Cairo University

MTPR Journal

 

Detection of interplanetary coronal mass ejections' signature using artificial neural networks

U+1F5132016-12-31 & doi: https://doi.org/10.19138/MTPR/(16)1-10
Ramy Mawad, A. Radi, R. Saber, A. Mahrous, Mohamed Youssef, Walid Abdel-Sattar, Hussein M. Farid, Shahinaz Yousef

We have estimated the arrival time of interplanetary coronal mass ejection (ICME) shocks during solar cycle 23 (the period from 1996 to 2007) using the artificial neural network. Under our model, we could match 97% of the listed coronal mass ejection CME-ICME events selected by Cane and Richardson (2010) using the initial velocities of the ICME events. Whereas, when we used the ICME velocity at a distance 20R⊙, our model succeeded to match only 84% of the listed ICME events. The prediction of CME travel-time correlated to the initial speed of CMEs, we found a high correlation coefficient between initial speed of CME and calculated travel time under our model (R≈74) with power fitting. The prediction of ICME arrival time can be better estimated from initial speed and linear speed of CMEs more than from final speed or speed at 20 R⊙.

HTML PDF

 

Evolution of the binary neutron star system PSR1913+16 due to gravitational waves emission

U+1F5132016-12-25 & doi: https://doi.org/10.19138/mtpr/(16)11-19
Shahinaz Yousef, Zeinab A. Mabrouk, Mostafa Kamal Ahmed

We have studied how the eccentric orbits of binary neutron stars evolve due to the emission of gravitational waves according to Popov and Imshennik method [1]. We have applied this method to PSR1913+16 binary system. Our results for this system are highly comparable with the latest analysis for that system based on published timing observations from 1974 through 2006 [2].The most important results from our study are: elliptical orbits shrink in size and become near circular at their late stages of evolution while the circular orbits don’t change their shapes; and most of the energy due to gravitational radiation emission is lost at high eccentricities near the periastron position.

HTML PDF

 

PROSPECTS of NUCLEAR PHYSICS WITH LASERS – DREAM OR REALITY?

U+1F5122016-12-17
T. Kuehl, P. Neumayer, B. Borm, D. Schneider, A. Yakushev, J. Khuyagbaatar, V. Bagnoud, Ch. Brabetz, F. Wagner, Th. Stoehlker

The application of lasers to drive nuclear reactions started as soon as the discovery of lasers was published. Soon afterwards laser fusion programs for power production where initiated. Already in the early1990’s reports on laser accelerated electron beams started the idea of laser driven nuclear reactions using laser accelerated particles. With the later advent of proton and light-ion acceleration reaching 10’s of MeV this idea became more and more realistic. For many practical application laser accelerated beams might soon reach a level of commercial applicability. The quest of a competitional role in the realm of advanced Nuclear Physics has started at least with the ELI projects, in particular ELI NP in Bukarest. In the talk experimental results in the direction of new laser acceleration schemes and the application of standard nuclear physics instrumentation for laser experiments will be discussed.

HTML

 

NEW ENERGY RESOURCES START FROM THE LATEST ACHIEVEMENTS of INTERNATIONAL RESEARCH

U+1F5122016-12-17
LOTFIA M. EL NADI

We plan to initiate unprecedented large experiment provided by high technological equipments that are widely used in international laboratories. The study of the interaction of high density laser fields with matter is an important rapidly expanding branch of physics since the last five years. The potential applications of this research are numerous, not only in physics, but also in new energy resources, chemistry, biology, material science, in the fast ignition approach to fusion, in accelerators, for relativistic electrons and for Nuclear effects and charged ion acceleration. Since their starting steps in 2000, high density short pulse (HDSP) lasers have been developed to generate very short pulses with typical high performance parameters. The study of the interaction of high density laser fields with matter is an important rapidly expanding branch of physics. The potential applications of this research are numerous and we shall present an approach to evaluate the economics of the Thermal Energy Production applying the High Density LASER INDUCED THERMAL ENERGY HD- LITE.

HTML

 

METALLOPORPHYRINS: STRUCTURE, BONDING and SELF-ASSEMBLING

U+1F5122016-12-17
A.M.Ionov, S.I.Bozhko, V.S.Bozhko, R.N.Mozhchil

Organic molecular films of porphyrins have attracted attention over the past years in view of potential applications as the templates for nanomaterials synthesis, nanoelectronic devices and for biology and medicine. For understanding and tailoring their properties the knowledge of electronic structure and bonding in porphyrins is required. The goal of these studies was to investigate the surface topography and the electronic structure of a valence band(VB) and core levels of tetraaril-porphyrins, RE(Yb, Er,) metals and Pt-group compounds (Pt-TPP(n-COOH3)4;etc). The electronic structure of VB, C1s, O1s, N1s, metal core levels and the topography of porphyrins were studied by PES and AFM. The HRPES studies were performed at the RGBL BESSY II using photon energies 120-600 eV. All elements of the compounds were found in XPS spectra. In TPP spectra two peaks of N1s at 399.8 and 397.8 eV (BE range) were assigned to sp3 and sp2 nitrogen, respectively. In metalloporphyrins the charge distribution is more uniform for N1s spectra of metalloporphyrins. Different peaks in spectra were related to the unequivalent C atoms in the molecules (aromatic and C-N-C groups). The valence band is formed by the states corresponding to π (2- 12 eV BE) and σ-states (8-16 eV) of macrocycles. AFM studies of thin films structure show that the structure of solid-phase films is determined by their chemical nature, supramolecular structure and interaction with substrates. These films self-assemble in the air under ambient conditions into partially ordered large rod-shaped and flat supramolecular nanostructures on flat substrates, with an average size in nanoscale, where the molecules are approximately parallel and cofacial to one another. The results of PES and AFM studies of topography and self-assembling processes in thin films of porphyrins are presented and discussed.

Acknowledgement This work was supported by Russian Academy of Sciences and the bilateral program “Russian-German Laboratory at BESSY”.

HTML

 

TOPOLOGICAL SEMIMETAL SB (111) WITH EXOTIC BEHAVIOR: STM, LEED and APRES STUDIES

U+1F5122016-12-17
S.I. Bozhko, S.V. Chekmazov A.M. Ionov, .A.A.Kapustin A.A. Smirnov, O.Yu.Vilkov*

Due to a strong spin-orbit interaction, the surface states of Sb (111) are similar to those for topological insulators. The surface states are protected by timereversal symmetry, and energy dispersion is a linear function of momentum. Surface modification (for example, defects in surface structure) leads to a local break of the surface translational symmetry and can change surface states. It is the primary reason to study the defects of Sb crystal structure and their effect on the surface states dispersion. Etching of the Sb(111) surface using Ar+ ions is a common way to create defects both in a bulk and on the surface of the crystal. For qualitative interpretation of the PE features we have provided the comparative experiments on at (111) surface and after ion etching. Sb(111) ion etching at room temperature reveals anomalous exotic behavior of a surface crystal structure. It results in the formation of flat terraces with a size of 2nm. Investigation of electronic structure of the etched Sb (111) surface has demonstrated an increase of density of states (DOS) at the Fermi level. The results are discussed in terms of local break of the Peierls transition conditions. The authors thank Russian-German laboratory at BESSY II and the Resource Center of Saint Petersburg State University “Physical Methods of Surface Investigation’’.

HTML

 

ELASTIC SCATTERING MEASUREMENTS at LHC and THEORETICAL INVESTIGATIONS

U+1F5122016-12-17
Fazal-e-Aleem

Large Hadron Collider (LHC) is offering a whole new ground for subatomic studies in the Tevatronenery regime. Elastic scattering is explored by the TOTEM Experiment which will offer us a clearer picture of diffractive scattering. Together with earlier measurements at GeV energies, theory faces a challenge. In our recent work, it was observed that by using Generalized Chou Yang model we can give a consistent picture of hadronic radii. In this talk, we will give an overview of current and future TOTEM measurements together with theoretical explanation.

HTML

 

STELLAR LABORATORIES

U+1F5122016-12-17
K. Werner

Atomic data for highly ionized species beyond the iron group are scarce. We have discovered hot white dwarf stars exhibiting spectral lines of this species, originating from atmospheric plasmas with temperatures of the order 100,000 Kelvin. Ultraviolet spectroscopy is executed with the Hubble Space Telescope. We perform quantummechanical calculations to obtain line-transition probabilities and level-excitation energies. The data are validated by feeding them into stellar atmosphere models to compute stellar spectra which are then compared to the observations. In this way, we were using stars to obtain, for the first time ever, atomic data of many heavy elements like Zn, Ga, Ge, Kr, Zr, Mo, Xe, and Ba in ionization stages IV-VII.

HTML

 

NUCLEAR ELECTRON TUNNELING in SUPERCOMPRESSED SUPERSONIC JET

U+1F5122016-12-17
Kholmurad Khasanov

The development of a special design of nozzles which we call dynamic emitter [1]allowed us to obtain asupersonic jet with spiral instability, super vibration and supercompression[2,3].When we pass this supersonic jet through an environment with thermoelectronic emission, we can observe the release of bulk energy and transformation of atoms [4,5,6] which is accompanied by gamma rays, x-rays, heat and light emission of high density of energy.These phenomena’s allows us to claim that the Nuclear Electron Tunnelling based on the quantum-mechanical effects are taking place in the nucleated continuum. Below are pictures of practical application of the phenomena:

References [1]Kh. Khasanov and S. V. Petukhov, “Dynamic Emitter,” PF Patent No. 2058196, 1996 [2]Kh. Khasanov, “Visualization of Super-Compressibility in Supersonic Spiral-Twisted Jets”, Physics Letters A, Vol. 376, No. 5, 2012, pp. 748-753. [3]Kh. Khasanov, “Double Spiraled Supersonic Jet,” Fluid Dynamics, Vol. 46, No. 3, 2011, pp. 433-436. [4] Kh. Khasanov, “Spatial Super-Compressibility of the Continuous Media in High-Frequency Fields”, American Journal of Modern Physics, 2015; 4(6): 281-286. [5] Kh. Khasanov, “Super-Comprehensibility Phenomenon”,Journal of Modern Physics, 2013, 4. [6] Radiation of Directed Gravitation High-Energy Photo 5th International Conference on Modern Trends in Physics Research, Cairo University, 2014

HTML

 

APPLYING PHYSICS to LIFE - DEVELOPMENT of HEALTHCARE TECHNOLOGY for THE COMMON PEOPLE - in THE LIGHT of BANGLADESH EXPERIENCE

U+1F5122016-12-17
Dr.K Siddique-e Rabbani

Technology and science are at the root of human civilization. In the medical scenario, right from the simple mercury thermometer to gigantic PET scanners, healthcare technology has proliferated to a stage beyond imagination of the common person; Physics being the major knowledge base behind all these developments. However, selfish desires to grab all the benefits led to unprecedented technology deprivation and unacceptable human sufferings to about 80% of the global population who eventually turned out to be the residents of the so called ‘Third World’ or the ‘Low Resource Countries (LRC)’.The educated and trained scientists and technologists in these LRCs contributed further to this divide by indulging in publication driven research or ‘glamourous’ research keeping themselvesin isolated ‘bubbles’ and being oblivious to the sufferings of their own populations who had supported all the expenditures in educating them and in bearing the costs of research, however meagre that may be. The author felt that the only solution to the above mentioned scenariolies in the development of technology needed to enhance the quality of life of the common people within each of the national boundaries, particularly within the LRCs and this realisation brought himstraight back home in 1978, after obtaining a PhD in microelectronics which was rather irrelevant to his country but offered high job prospects in the North. At home he looked for avenues in science that could be useful to the people.A research in a medical problem initiated by a senior gave him a direction and a subsequent academic link with UK scientists boosted the horizon and expertise. Over the last 38 years the author’s team developed severalmodern healthcare devices including computer based ones which are being used in hospitals, clinics or by patients, even beyond the borders of Bangladesh. Some wereroutinely used for more than twenty years, unimaginable for any imported equipment! These devices include, i)Computerised EMG/Nerve conduction equipment, ii) Computerised ECG equipment (also used in telemedicine for online transmission of data), iii)Computerised dynamic Pedograph (for foot pressure distribution mapping), iv)Iontophoresis equipment for treatment of excessive sweating (used by patients at home), v)Muscle & Nerve stimulator (for physiotherapy), vi) Low cost semi-functional mechanical prosthetic hand, vii) Intraoperative Neuro Monitor (for monitoring nerves during brain or spinal surgery) and viii) Electrical Bio-Impedance devicefor localised physiological monitoring.Such efforts also gave the expertise and experience to fill in gaps that were revealed when the devices were used for clinical work or for research, which led to innovations in the areas of nerve conduction in the form of a new parameter, ‘Distribution of FLatency (DFL)’ and in general physiological study and diagnosis through another new technique, ‘Focused Impedance Method (FIM)’. Both of these have been taken up for research by advanced universities of the world including Norway and UK.The author’s team deliberately refrained from taking out patents, rather they have established an ‘International Centre for Technology Equalisation (ICTEq)’ for dissemination of the matured technologies. They have also innovated very simple techniques for providing germ-free drinking water using solar Pasteurisation that a rural user can make from easily available materials. The author’s group also got involved in the manufacture and dissemination of the developed technology and in establishing a telemedicine network within the countrydeveloping their own hardware and software. The success of all the above effort has started to become visible and has beenacclaimed nationally and internationally. Financial support has also started pouring in from national and international sources. All these efforts and models for dissemination have immense potentials to solve some of the major problems in the healthcare sector, particularly in the LRCs and the author expects serious discussions on these issues in a forum such as the MTPR-2016.

HTML

 

SURFACE NANOENGINEERING: WRITING WITH OXYGEN ADATOMS on THE oO2/MO(110)SURFACE

U+1F5122016-12-17
S.Bozhko1,2, K.Walshe1, B.Walls1, O.Lübben1, B.Murphy1, V.Bozhko3, I.Shvets1

Writing at the nanoscale using the desorption of oxygen adatoms from the oxygen-rich MoO2+x/Mo(110) surface is demonstrated by scanning tunneling microscopy (STM). High-temperature oxidation of the Mo(110) surface results in a strained, bulk-like MoO2(010) ultra-thin film with an O–Mo–O trilayer structure.Due to the lattice mismatch between the Mo(110) and the MoO2(010), the latter consists of well-ordered molybdenum oxide nanorows separated by 2.5 nm. Further oxidation results in the oxygen-rich MoO2+x/Mo(110)surface, which exhibits perfectly aligned double rows of oxygen adatoms,imaged by STM as bright protrusions. Individual oxygen adatoms can be removed from the surface by pulsing at positive sample biases greater than 1.5V (Fig. a,b.c). Adatoms were removed from the surface both when STM tip was in tunneling contact and when it was far from the surface (tunneling current was absent). Tipmovement along the surface can be used for controlled lithography (or writing) at the nanoscale, with a just atomic sizeofa feature (Fig. d). By moving the STMtip in a predetermined fashion, information can be written and read by applying specific biases between the surface and the tip.

HTML

 

PLASMA OPACITY of THE SUN and EXOPLANETARY HOST STARS

U+1F5122016-12-17
Sultana N. Nahar

Thousands of extra-solar planets have been discovered thus far, mainly by the space based observatory KEPLER. Host stars of exoplanets generally fall under a category of "cool dwarfs" like our Sun, specially G, K, F, and M-class stars. Most stars belong to this category, with stellar fluxes that are not too intense for planetary atmospheres to exist. Of particular interest are Earth-like planets and solar-type stars, forming a star-planet system in the so-called "habitable or Goldilocks" zone where liquid water may also be found. The primary technique for detecting exoplanets is planetary transit across the host star, and measurement of resultant variation in stellar flux. However, the variations are extremely slight, and interpretation of observation requires precise knowledge of stellar atmospheres and detailed knowledge of emitted spectrum. In particular, the predicted near-UV flux is important since Earth-like life forms are highly sensitive to it. However, current model spectra of cool stars do not accurately reproduce observed fluxes even for the Sun. The problem lies in the attenuation of transmitted flux due to the opacity of plasma comprising stellar atmospheres. The computations for opacity are highly complex, requiring non-localthermodynamic- equilibrium (NLTE) models using a vast amount of atomic data for a plethora of UV lines and continuous opacity, especially for relatively low ionization stages of abundant elements such as carbon, sililcon and iron, and ions such as nuetral and singly ionized Fe I-II. Radiative atomic processes responsible for photon absorption and opacity can now be computed with high accuracy using state-of-the-art atomic physics and computer codes. The most powerful theoretical methodology is the R-Matrix method that is capable of producing highly detailed photoionization or bound-free cross sections and millions of transition probabilities among hundreds to thousands of atomic levels.

HTML

 

STM INVESTIGATION OF INTERFACIAL BAND BENDING IN AU-TIPPED CD-CHALCOGENIDES HYBRID NANOSTRUCTURES

U+1F5122016-12-17
Hassan Talaat

The interfacial electronic structure of Au-tipped CdX (X = S, Se and Te) hybrid nanostructures (HNSs) have been studied by UHV scanning tunneling spectroscopy (STS) at room temperature. Au-tipped CdX (X = S, Se and Te) HNSs were synthesized by phase transfer chemical methods. The dimensions were determined by the scanning tunneling microscope (STM), the high resolution transmission electron microscope (HRTEM) and the optical absorption. The measured dimensions using these techniques are consistent, giving Au tip average size within the range of [2.5, 3.5] nm and Cd-chalcogenides quantum dots (QDs) nanoparticles (NPs) average size within the range of [3.5, 4] nm. The STS at the interface of Au-tipped CdS and CdSe HNSs detects a downward band bending towards the interface ~0.25 ± 0.01 eV and 0.18 ± 0.03 eV respectively, indicating an electron accumulation at these interfaces. However, an upward band bending towards the interface of ~0.78 ± 0.01 eV is measured by the STS at the interface of Au-tipped CdTe HNS, indicating electron depletion at the interface. The band bending values were also confirmed using the corresponding calculated models of the energy band diagrams. These different behaviors were also observed in the UVevis absorption of Autipped CdS and CdSe HNSs, which shows exciton bleaching features, but an exciton increasing feature is observed in the case of Au-tipped CdTe HNS. These later results are explained as a result of the presence of electron accumulation at the interface of Au-tipped CdS and CdSe HNSs, and also an electron depletion at the interface of Autipped CdTe HNS. Such determinations of the interfacial band bending in Au-tipped Cd-chalcogenides HNSs have significant consequences on the charge separation efficiency and the photo-response behavior. Furthermore, the presence of these bands has a direct impact in the field of applying plasmonics for improved photovoltaic solarcells.

HTML

 

THE APPLICATION OF ATOMIC FORCE MICROSCOPY (AFM) IN NANO-BIOPHYSICS

U+1F5122016-12-17
Hosam Gharib Abdelhady

We applied the 4D AFM to:

First: Film the landing of individual, flexible nanomolecules onto atomically flat surfaces from a very diluted aqueous drop. How these nanomolecules start making a monolayer? How they behave when they just meet a single, free moving biomolecules (DNA in this study)? Finally, how we applied these results in producing individual, targeted nanoparticles for cancer treatment?

Second: Image in nanoscopic scale the DNA damage bysmall and large Au NPsin near physiological conditions.

Finally: Capturethe mechanism(s) of enzymaticaction on a very short RNA rods. We believe that these points will increase the application of 4D-AFM in biophysics and Nanomedicine.

HTML

 

OPTICAL and ELECTRICAL PROPERTIES of AG/PVA NANOCOMPOSITES for AN ORGANIC ELECTRONIC APPLICATIONS

U+1F5122016-12-17
Kamal M. Abd El-Kader, Wahib M. Attia, Ahmed .G. El-Shamy

In the present work, Poly (vinyl alcohol)-silver (PVA-Ag) nanocomposite films with thickness 0.18 mm, constant silver content (0.4 wt. %) and different time of reactions (0.1, 3, 5, 7, 9 h) were prepared by the chemical reduction (in-situ) method. Structural and optical properties of PVA-Ag nanocomposite were studied by Uv-vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), atomic force microscope (AFM) and photoluminescence (PL) spectroscopy. Optical absorption studies showed an additional peak at 427 nm for different films and a peak at 210 nm for undoped PVA film. It was found that the root mean square (RMS) roughness, the average diameter of Ag nanoparticles and optical energy gap decrease, while PL intensity, the conductivity, and the absorbed intensity at 427 nm increase as the time of reaction is increased. XRD results showed the formation of silver nanoparticles with (FCC) phase in the PVA matrix. The dielectric constant (ε') value decreased with the increasing the time of reaction. The conductivity and dielectric loss were increased with an increasing the time of reaction. Poole - Frankel emission is the prevailing transport mechanism for all samples.

HTML

 

AN INNOVATIVE HYBRID REGULARIZED KACZMARZ-BAT APPROACH for UXO DETECTION FROM ITS GRADIENT MAGNETIC ANOMALY

U+1F5122016-12-17
M. Abdelazeem 1, E. Emary 2 and M. Gobashy 3

Different countries suffer from the problem of detecting and locating the unexploded ordnance (UXO) after military events. Such a problem has a great impact on economic development and future plans. Egypt is one of those countries, where more than 23 million UXOs are expected to cover a wide part of its northwestern desert. Detection of UXO becomes a persistent target for many geophysical research teams. Currently, unconventional near-surface flight technologies, such as quad/hexa-copters instead of regular land surveys, are used for safety reasons in the acquisition phase. In the interpretation phase, the analytical methods played challenging role to solve such ill-posed problems using the regularization tools especially those based on Tikhonov formula. Those methods still have limitations when dealing with highly ill-posed problems. Fortunately, neither noise nor ill-posedness affects the quality of the solution produced by artificial intelligence based techniques. Hence, the application of the hybrid regularize/artificial intelligence based technique would present a promising choice. In this work, we implement the Kaczmarz-Bat technique, which holds the power of the regularizing analytical technique as an initial good solution and the benefits of artificial intelligent technique, represented in bat method to enhance the solution. The gradient magnetic field over UXO objects was sliced into profiles and solved using the proposed approach as 2D earth models. The solutions are stacked together in a 3D perspective model illustrating the depth and location of the targets.

HTML

 

NEWLY EMERGING PHOTONIC TECHNOLOGIES: FUNDAMENTALS and APPLICATIONS

U+1F5122016-12-17
SALAH OBAYYA

The turn towards optical computers and photonic integrated circuits in high capacity optical networks has attracted the interests of expert researchers nowadays. This is because all optical packet switching and routing technologies hold promise to provide more efficient power and footprint scaling with increased router capacity. Therefore, it is aimed to integrate more optical processing elements into the same chip, and thus, increase on-chip processing capability and system intelligence. The merging of components and functionalities drives down packaging cost, bringing photonic devices one step (or more) closer to deployment in routing systems. Photonic crystal devices can be functionally used as a part of comprehensive all photonic crystal based system, where on the same photonic crystal platform, many functionalities can be realized. Therefore, photonic crystals have recently received much attention due to their unique properties in controlling the propagation of light. Many potential applications of photonic crystals require some capability for tuning through external stimuli. It is anticipated that the photonic crystals infiltrated with liquid crystals (LCs) have high tunability with external electric field and temperature. For the vast majority of LCs, the application of an electric field results in an orientation of the nematic director either parallel or perpendicular to the field, depending on the sign of the dielectric anisotropy of the nematic medium. `Plasmonics' is a relatively new term in Optics which refers to applications or phenomena in which surface plasmons (SP) are involved. Recently, the scientists and engineers of several disciplines have turned their attention to the plasmonic effects and their applications.This is because advances in technology have allowed fabrication and patterning of metallic structures in nanometer scale. Further, the SP waveguides can confine the light in nanoscale dimensions beyond the diffraction limit. Therefore, more compact optical systems can be developed based on the plasmonic waveguides. In almost all cases, an accurate quantitative theoretical modelling of these devices has to be based on advanced computational techniques that solve the corresponding, numerically very large linear, nonlinear or coupled partial differential equations. In this talk, the different computational modelling techniques will be introduced. In addition, novel designs of high birefringence LC PCF infiltrated with a nematic liquid crystal (NLC-PCF) are presented and analyzed. Moreover, due to their different uses in communication systems, the performance of novel designs of high tunable polarization rotator, directional coupler, polarization splitter, plasmonic multiplexer-demultiplexer, plasmonic temperature sensors based on the NLC-PCF will be introduced. The simulation results are obtained using full vectorial finite difference method, full vectorial finite difference beam propagation method, and finite element method (FEM) with nonuniform meshing capabilities and perfect matched layer boundary conditions.

HTML

 

TOWARDS DIAGNOSTICS and MONITORING of DISEASE BIOMARKERS in EXHALED BREATH USING FREQUENCY COMB LASER

U+1F5122016-12-17
T. Mohamed1,2, F. Zhu1 , J. Strohaber1 , A. A. Kolomenskii1 , and Hans A Schuessler1

Breath analysis is a non-invasive method for monitoring the volatile organic compounds present in the human breath and is one of the clinical tests that can be used for early disease detection. The advantages of breath analysis in comparison to blood or urine analysis includes it is non-invasive, easily repeated, and does not cause any infections. In this connection an optical setup based on a frequency comb laser and a multipass optical cell has been developed for breath analysis. The multipass optical cell is formed by six highly reflective confocal mirrors to achieve long optical path of 600 m in a cell of only of 0.5 m in length. The frequency comb lasers are a broadband fiber laser beams with spectral range spanning from 1500 nm to 1700 nm and from 3100 to 3400 nm. The relevant spectrum covers many biomarkers, including ethane, acetone, methane, ethylene, carbon dioxide, carbon monoxide, ammonia, and methylamine. For testing the optical setup, the absorption laser spectroscopy measurements in the near/mid IR of acetone, methane, carbon dioxide, carbon monoxide gasses were carried out. For methane and acetone a signal to noise ratio of 120 was obtained and the detection limits were ~ 1.5 ppmv and ~ 2 ppmv respectively. Also a brief description of a new laser facility at Beni-Suef University, Egypt will be discussed during the conference.

HTML

 

NERATION ULTRAFAST WHITE-LIGHT LASER PULSES

U+1F5122016-12-17
Walid Tawfik

Ultrafast laser pulses have beenvital for a varietyof developed applications like: X- ray free electron laser generation X-FEL, femtosecond laser pulses induced high harmonic generation and as an essential means for creation of ultraviolet coherent attosecond laser pulses [1]. Recently, high power table-top laserschemebasically depends on Ti:Sapphire as an amplifiermedium, and some terawatt-class laser systems have been established [2]. Nevertheless, these sophisticated systems have serious problems like pulse deformation due to thermal load on the amplifiers and thermal lensing particularly inside the laser rod [3]. In this work, generation and characterization of broadband-ultrafast high energy laser pulses have been considered using a relatively simple methodology. The characterization of ultrafast pulses in the regime of few-cycle pulses has been considered using spectral phase interferometry for direct electric-field reconstruction (SPIDER) [4]. These pulses were produced due to supercontinuum triggered by self – phase modification (SPM) in neon gas filled hollow-fiber followed by a set of chirpedmirrors for dispersion compensation. The generated output pulses after compression achieved ~ 5femtosecond pulse duration with high energy of sub-mJ at 1 KHz repetition rate. The output spectral bandwidth found to cover broadrange from 550 – 950 nm.It has been found that the out put pulse width is affected by thepulse duration of the injected femtosecond pulses into the optical fiber under different gas pressures. The obtained pulses may give a chance to create high harmonic generations HHGwhich could be used for generation of extremely short pulses down to x-ray regime with short pulse durations down to attosecond regime in future.

HTML

 

FIFTIETH ANNIVERSARY of GENERATING THE FIRST SOLAR LASER (50 Years Solar Laser)

U+1F5122016-12-17
Yasser A. Abdel-Hadi

Solar laser is one of the novel branches in recent technology. This branch has been developed from the combination of two sciences; solar energy and laser physics. The workers and researchers in the field of laser are celebrating the golden jubilee of the invention of solar laser (or solar generated (or pumped)) laser. It was a great success to use the solar energy to generate the laser beam which usually needs high energy to get generated. The idea of directly converting broad-band solar radiation into coherent and narrow-band laser radiation represented a new success of the geometrical-optics-based solar energy. This way of thinking was a very good solution to obtain the laser beam from the solar energy. A trip of 50 years of solar laser and its applications is summarized in this presentation.

HTML

 

CHARACTERIZATION of LA0.7SR0.3MNO3 THIN FILMS by PULSED LASER DEPOSITION for SOFC APPLICATION

U+1F5122016-12-17
A.A. El-Aziem*a, Y. Badra, K.M. El-Khatibb, M. A. Hafez a

La0.7Sr0.3MnO3 (LSM) polycrystalline was synthesized using sol gel method at 600 ᵒC. The structure and elemental analysis were confirmed by XRD and EDX respectively with rhombohedral crystal structure. HR-TEM imaging showed that the prepared LSM has uniform shape with agglomeration and average size from 100- 200 nm by PSD. Thin films of LSM with 97 nm were deposited on clean Si (100) single crystal substrate by PLD using Nd: YAG (1064 nm) with 10 Hz repetition rate and 6 ns pulse duration at room temperature in high vacuum of ~ 6´10-6 Torr. LSM films were annealed at temperatures of 400, 600, 800 and 1000 ᵒC for 2h. The XRD indicated that crystallization is enhanced by increasing annealing temperature. Additionally, grain size was increased by rising annealing temperature as indicated from FESEM imaging. The average roughness (Ra) and root mean square roughness (Rq) were decreased by increasing annealing temperature up to 600 ᵒC then increased by further temperature increasing as showed by AFM images. Raman spectra were recorded in wave numbers 100-100 ٠cm-1 and all major peaks appeared at annealing temperature 1000 ᵒC. The electrical and dielectric properties for the as deposited film and films annealed at different temperatures also recorded in temperature ranges from room temperature to 200 °C and found to be sensitive to temperature and open possibility for using LSM as cathode part in solid oxide fuel cell (SOFC).

HTML

 

STORAGE of FEMTOSECOND LASER PULSES in AN OPTICAL TRAP

U+1F5122016-12-17
Abdullah Shehata1, Mohamed Yassien1, Mona Ali1, Tarek Mohamed1, Reinhold Schuch2

An optical trap for storing femtosecond laser pulses was investigated theoretically to enhance the interaction efficiency with optically thin targets. The optical trap consists of an electro-optical switch, high reflective mirrors and a focusing system. The efficiency of the optical trap is strongly depends on the optical losses from the optical elements of the trap [1]. To compensate the optical losses, Ti: Sapphire crystal as an amplifying medium was implemented in the optical trap. It has high saturation fluence ≈ 0.9 Jcm-2, and upper state lifetime of 3.2 μs. These parameters do not cause a quick extraction of the stored energy from the amplifying medium and keep the intensity of stored laser pulse constant over 3.2 μs [2]. In the theoretical investigations, we had studied the trapping of femtosecond laser pulses of wavelength 800 nm, 1mJ energy per pulse, 10 Hz repetition rate and with different pulse duration times. Due to the propagation of these laser pulses through the optical trap both of phase self modulation and group velocity dispersion, introduce large broadening for the laser pulses that have the initial duration time <500 fs. To compensate this broadening, chirped mirror with suitable properties can be used. Power consideration showed an increase in the average power of the laser system when the optical trap that includes a Ti: Sapphire by a factor of 165 times compared to single passage of the laser pulse. Also the laser pulse could be stored in the optical trap for 4 μs. Comparison between the available experimental data and our theoretical data showed a good agreement.

HTML

 

GROWTH OF SILVER OXIDE (AgO) THIN FILMS BY PULSED LASER DEPOSITION

U+1F5122016-12-17
Hisham Imam1, Ahmed Elbanna2, Mohamed A. Hafez1, Inas ElZawawi2, Yosr Gamal1

In this work, a series of Silver Oxide (AgO)thin films on silicon substrates by pulsed laser deposition (PLD) are studied at different deposition conditions and constant oxygen pressure 0.3 mbar. The thin films were prepared by Nd:YAG laser (1064 & 532 nm) with 10 Hz repetition rate and 6 ns pulse duration.The effects of ablation time (Tab) on the structural and optical properties ofAgO thin films by grazing incident X-ray diffraction (GIXRD).XRD and TEM result confirmed that the structure of the films prepared by the fundamental wavelength of Nd:YAGlaser at constant oxygen pressure 0.3 mbar were nanocrystalline monoclinic AgO. The optical band gap of the thin films which prepared using the fundamental and second harmonic of Nd:YAG laserdecreases with increasing the Tab. The partical size (Ps) of nanocrystallineAgO thin film increases by increasing the ablation time Tab that effects on the optical properties of the AgO films. The controlling of the optical properties thin films which were prepared by PLD technique could be arbitrated for certain application with controlling the ablation time Tab at fixed constant oxygen pressure. Influence The polycrystalline of cubic inverse spinel structure with the appearance of secondary phase was appeared at 900oC. The Raman spectra gave the peaks corresponding to the tetrahedral and octahedral groups. VSM measurements showed that enhancement of magnetization with an increase annealing temperatures.

HTML

 

HIGH INDEX OF REFRACTION AND OPTICAL FREQUENCY GENERATION FORMED BY METAMATERIAL BASED ON PLASMONIC SPHERICAL NANOPARTICLES

U+1F5122016-12-17
S.I.Hassab Elnaby and Norhan Salama

Metamaterials have been one of the most attracted strikethrough scientific topics in many disciplines due to their achievable extraordinary optical properties including negative index of refraction, Near-zero index and ultra high index of refraction. The three dimensional FDTD method is employed for investigating the electromagnetic propagation through a proposed structure of metamaterial based on periodic arrays of gold spherical nanopaticles. The optical properties of the structure are investigated as a function of gap distances between the metallic nanoparticls. The structure exhibit an increment of index of refraction by increasing the gap distances reaching up to 10.16 at the gap distance (a=750nm) for incident wavelength λ=500nm with transmission about 30%. Interesting phenomena of generation of new frequencies (induced frequencies) with high amplitudes are observed. The induced frequencies are transmitted outside the structures.

HTML

 

Fusion Energy by Ultra Intense Laser Initiated Nuclear Reactions with Aluminum Targets

U+1F5122016-12-17
Lotfia El Nadi1,2*, M. Ramadan3, M. El Nagdy4, A.Naser A. El Fetouh1

Ultra Intense Laser UIL interaction with Al27 target could possibly give rise to a nuclear rection of the target nuclei with the accelerated target charged ion in the laser field. The residual radioactive nuclei of Mn 52 and Mn 51 could well be due to evaporation of deuterons and tritons from the created compound nucleus according to the nuclear reaction: Al27 (Al27, H2) Mn52 and AL27 (Al27 + H3) Mn51 We here with report simulation of compound nucleus formation followed by particle evaporation applying Monto Calro code PACE-4 to estimate the possible cross-section for forming highly excited compound nucleus Fe54 leading to the final Nuclei Mn52 and Mn51. The results shown in the figure below indicate that the highest cross section of such possible two reactions is peaking at Al27 ions projectile energy ≈ 60 MeV (2.222 MeV/ A ) and 70 MeV ( 2.593 MeV/A ) respectively. The cross sections for production of the neutron deficient Mn nuclei resulting from the two above mentioned nuclear reactions of Al27 + Al27 are also estimated. The estimated crosssection of Mn52 and Mn51 positron emitters shown in figure indicate maximum values of approximately 30 and 150 mb at the aluminum ion energies mentioned above respectively. The nuclear reactions leading to Mn positron emitters are expected to also provide deuterons and tritons with the same cross-sections, The energies of these particles (H2 and H3) are calculated considering the newest standard Tables of the Atomic Masses. Possible acceleration of these emitted particles in the laser field is also expected. The Possibility of a new approach of fusion of the deuterons and tritons without implosion during the confined short laser pulse duration is proposed. In this approach an intense laser field equal or above 100 Peta Watt/cm2 would be needed. Simulation calculations for the form factors will be reported. The design of the experimental set up to be applied to attain such Fusion energy and overcome probable difficulties will be elaborated.

HTML

 

CHARACTERISTICS of METAL SURFACES COATED by THERMAL SPRAYING and LASER COATING

U+1F5122016-12-17
Sameh Akila1, M. A. Hafez1, M. Atta Khedr1, Ali S. Khalil2

Two ways had been used for obtaining coating of Nickel – 5%Aluminum as a bond coat followed by Magnesia-Stabilized Zirconium Oxide(ZrO2-18 to 25%MgO), Calcia-Stabilized Zirconium Oxide(ZrO2 -5%CaO) and mix from them as a top coat on the surfaces of Stainless Steel 304 (S.S. 304) specimens; were Thermal Spraying and Laser coating. The Thermal spraying coating was done by Air/Atmospheric plasma spraying APS using a PLASMA-TECHNIK AG Switzerland and F4-MB (machine-plasma torch), however CW 1.06 μm Nd-YAG diode pumped laser with maximum output power 2200W has been used for laser coating/cladding LC. The microstructure and mechanical properties of both coatings were investigated by scanning electron microscopy, X-ray diffraction, wear resistance and microhardness tests. The measurements showed the preference of the laser coating/cladding over the thermal spraying coating; where the internal microstructure showed more homogeneity of LC than APS coatings, The LC process involved complete melting of the coating powder in the laser generated melt pool followed by rapid solidification. The hardness of the coating layer was approximately 1600 Hv compared with only 400 Hv for the APS coating.

HTML

 

A HIGH-FINESSE FABRY–PEROT CAVITY WITH A FREQUENCY-DOUBLED GREEN LASER FOR PRECISION COMPTON POLARIMETRY at JEFFERSON LAB

U+1F5122016-12-17
Mohamed A. Hafez, Abdurahim Rakhman, Sirish Nanda, Al W. Tobias, Gordon D. Cates

In Jefferson Laboratory, Hall A experiments using a polarized electrons beam require measurement of the beam polarization accurately. The Hall A Compton Polarimeter (CP) utilizing the principle of Compton scattering of electrons from a circularly polarized photons measures the polarization of the electron beam from cross section asymmetry of scattered photons and electrons. CP is a superior technical solution since it is non-destructive for the electron beam. A high-finesse Fabry–Perot cavity with a frequency-doubled continuous wave green laser (532 nm) has been built and installed in Hall A of Jefferson Lab for high precision Compton Polarimetry. The infrared (1064 nm) beam from a ytterbium-doped fiber amplifier seeded by a Nd:YAG nonplanar ring oscillator laser is frequency doubled in a single-pass periodically poled MgO:LiNbO3 crystal. The maximum achieved green power at 5 W infrared pump power is 1.74 W with a total conversion efficiency of 34.8%. The green beam is injected into the optical resonant cavity and enhanced up to 3.7 k W with a corresponding enhancement of 3800. The scattered electrons and photons are detected using an electron and photon detectors. All the devices of the setup are installed on an optical table which is located between magnetic dipoles (Polarimeter Chicane). The polarization transfer function has been measured in order to determine the intracavity circular laser polarization within a measurement uncertainty of 0.7 %. The PREx experiment at Jefferson Lab used this system for the first time and achieved 1.0 % precision in polarization measurements of an electron beam with energy and current of 1.06 GeV and 50 μA.

HTML

 

INFLUENCE OF PLASMA FORMATION ON THE SUPERCONTINUUM GENERATIONBYFEMTOSECOND LASER PULSE IN PHOTONIC CRYSTAL FIBERS

U+1F5122016-12-17
Hisham A. El-Kolaly

The processes affecting the spectrum of the pulse is studied. Amongthese are self-phase modulation, nonlinear self-focusing, plasma generation, andgroup velocity dispersion. The combination of these factors leads to an asymmetric spectrum. If group velocity dispersion cannot arrest nonlinear self-focusing, selfphase modulation, coupled with nonlinear self-focusing, gives rise to a red shifted spectrum. In case plasma is generated, large blue shifted components are observed. The maximum blue shift is determined by both the maximum value of the electron density, and the distance over which the plasma extends. Interaction Picture Method in combination with the Conserved Quantity Error method for the step-size determination is adapted for the calculations.

HTML

 

Growth of Gadolinium Doped Cobalt Titanium Ferrite Thin Films by Pulsed LaserDeposition

U+1F5122016-12-17
Mohamed A. Khedr, Aya A. Elamy, Mohamed A. Hafez, Hisham Imam

Cobalt ferrite thin films are receiving increasing interest in applications such as magnetic sensors, microwave devices, and highdensity recording media due to their high permeability, high Curie temperature, and chemical stability. In this work, a series of Gd doped Co-Ti ferrite (Co1.1Ti0.1Gd0.04Fe1.76O4) thin films on silicon substrates by pulsed laser deposition (PLD) are studied at different deposition conditions in high vacuum of ~2x10-6Torr. The thin films are prepared by Nd:YAG laser (1064 nm) with 10 Hz repetition rate and 6 ns pulse duration. The Co1.1Ti0.1Gd0.04Fe1.76O4 thin films were prepared by PLD and followed byannealing at 300C, 500C, 700C, and 900C, for 2h in air.The thin films structural properties, and magnetic properties were investigated by X-ray diffraction (XRD), Raman spectroscopy, and Vibrating Sample Magnetometer (VSM). XRD result confirmed that the single phase of cubic inverse spinel structure of CoFe2O4at 300, 500, and 700oC with preferred orientation (311) for silicon substrates. The polycrystalline of cubic inverse spinel structure with the appearance of secondary phase was appeared at 900oC. The Raman spectra gave the peaks corresponding to the tetrahedral and octahedral groups. VSM measurements showed that enhancement of magnetization with an increase annealing temperatures.

HTML

 

STUDY and SIMULATION FUSION REACTION of ACCELERATED PROTONS WITH BORON INDUCED by HIGH POWER LASER

U+1F5122016-12-17
Lotfia M. Elnadi1,2, Omar Emara1, Dalia M. Osman1

In this work, we study the interaction of accelerated protons using High Power Laser with a Boron target through Fusion Nuclear reaction and calculate the cross section of production of Carbon -12 nuclei. Recently the progress of developing Laser systems has been rising with great pace. Experimental Physics of Laser produced Plasma has been developed accordingly. Now Laser systems capable of generating High Density Short Pulses can be achieved by several ways such as chirped pulse method (CPM). This method provides Laser beams with a high density and Pulses of duration about 30-50 fs which can be used in many fields. The interaction of such laser beams with targets of light nuclei such as Boron can introduce Inertial Fusion. A Simulation calculation of the interaction of accelerated protons by High Density Laser with Boron is being elaborated in this study The following graphs are the plots for the yield of the nuclear reaction between H+ and B where the proton is the projectile accelerated by laser of energies between the range of 1 to 300 MeV towards the Boron target. These cross sections have been calculated using the program PACE-4 which is part of the Lise++ packages that is based on the Monte Carlo method. In this graph, it was found that the highest cross section was 709 mb at an energy of 2.9 MeV. There were also other Carbon isotopes found as residuals to the reaction which are demonstrated in the following graph. Further part of the study will be a comparison between the collected data and experimental data performed using similar laser systems.

HTML

 

PHOTODEGRADATION OF PESTICIDES USING CORE-SHEEL NANOCOMPOSITES IN WASTWATER

U+1F5122016-12-17
Dina Momdouh Fouad, Nader Kamel Abed elmoniem, Mona Bakr Mohamed

In our study nanocomposites of TiO2-Au and ZnO-Au core-shell nanoparticles have been prepared via colloidal chemical method. The particle size, shape and chemical composition have been determined via high resolution transmission electron microscope (TEM) and X-ray diffraction (XRD) analysis. These nanomaterials have been used as a photocalalysts for photodegradation of organic waste for water purification. Primicarb is one of the most commonly used pesticides in Egypt, the degradation of 20 ppm primicarb under ultraviolet (UV) and visible light in the presence and absence of TiO2, TiO2-Au, and ZnO-Au nanocomposite was analyzed with high performance liquid chromatography (HPLC) and UV-Visible Spectra. The rate of the photodegradation and the catalytic activity of thesenanomaterials have been determined and compared. The results indicate that the core-shell nanoparticles is much more active catalyst in presence of sun light than pure TiO2 nanomaterials which has absorption maximum at 370nm.

HTML

 

A SENSITIVE MAGNETO-OPTICAL CURRENT SENSOR FOR HVDC NETWORKS

U+1F5122016-12-17
R. El-Bashar, J. El-Azab, Salah H. El-Naby

Currently, optical sensors (OSs) have become a contestant to conventional sensors especially in hazard environments. Magneto optic current sensor (MOCS) is considered a new solution for measuring high dc currents in high voltage direct current (HVDC) networks. Moreover, it provides the ability to be interfaced easily with fiber-optic based Ethernet local area networks. These features make it smart in monitoring the condition of the network in case of failure. A MOCS with polarimetric configurations is estimated using a small optical glass sensor SF-59 into a gapped toroid iron core. The light source wavelength used is from a laser LED at 435.8 nm, the maximum current measured is nearly 3000 A being limited by the maximum output of variac. The output test result proves that the sensor become more sensitive in comparable with laser led at 632 nm and the ability of the sensor to be used as a current sensor in HVDC networks and protect DC motor.

HTML

 

NOVEL PEROVSKITE – GRAPHENE COMPOSITE APPROACH TO ENHANCE THE PHYSICAL PROPERTIES OF LAFEO3

U+1F5122016-12-17
Ebtesam E. Ateia, and Seham K. Abdel-Aal

Graphene acts as an excellent supporting material in the preparation of a variety of nanocomposites. In the present study synthesis of LaFeO3/GO was carried out through citrate gel auto combustion method. X-ray diffraction, Field emission scan electron microscopy and Fourier transform infrared spectroscopy were used to study the effect of GO on the structural, magnetic and optical properties. The XRD peak shows that all the diffraction peaks of LaFeO3/GO nanocomposites can be assigned similar to a single phase LaFeO3 belonging to orthorhombic distorted perovskite LaFeO3 phase [1]. The calculated average grain size is in the range of 26 to 45 nm. The synthesized LaFeO3-graphene nanocomposite can be potentially used as a visible-light responsive magnetically separable photo catalyst and hence as a powerful separation tool to deal with water pollution problems.

[1] Xiao Ren, Haitao Yang, Sai Gen, Jun Zhou, Tianzhong, Royal society of chemistry, 2016, 8, 752.

HTML

 

Enhanced Light Trapping in Thin Film Solar Cells

U+1F5122016-12-17
Mohamed F. O. Hameed, and S. S. A. Obayya

The potential to enhance the light trapping inside thin-film solar cell (SC) has been widely addressed to improve the SC efficiency and substantially reduce its cost. Thin-film SC offers a significant cost reduction compared to traditional bulky thick film SCs. However, the overall performance of thin-film SC is not optimal due to its low absorption. To address the weak optical absorption in Si thin films, several nanostructures such as nanowires, diffraction gratings and plasmonic scatters have been employed to enhance the ultimate efficiency of the Si SC.In this regard, novel light trapping techniques such as funnel NWs, and plasmonic thin film SC will be presented. The optical properties of the studied designs are numerically investigated by using 3D finite difference time domain method.The numerical results show that around 35% absorption improvement has been achieved using plasmonic nanoparticles compared to the conventional thin film SC.Further, funnel shaped SiNWs offer an ultimate efficiency of 41.8% with an enhancement of 54.8% relative to conventional cylindrical SiNWs.

HTML

 

EFFECT OF HEAT AND LIGHT INTENSITY ON (I-V) CHARACTERIZATION OF CU2S FILM / P- SI HETEROJUNCTION”

U+1F5122016-12-17
M.M. Saadeldin1, M.M. El-Nahass2, K. Sawaby1.

Cuprous sulphide was deposited on p-type silicon substrate by thermal evaporation technique to form Cu2S film / p-Si heterojunction, and deposited on glass to measure the thermoelectric power. The thickness of Cu2S film is (d = 113 nm), the structure of Cu2S thin film investigated by X-Ray diffraction (XRD). XRD pattern shows that the powder of Cu2S has a polycrystalline nature and also the thin film. By indexing the peaks, Cu2S is defined as orthorhombic crystal system with lattice parameter [a=11.82 Å, b= 27.05 Å, c =13.43Å]. Surface morphology and grain size has been obtained by transmission electron microscope (TEM). TEM) for a deposited Cu2S thin film shows a nanocrystalline structure with average grain size 43 nm. .The thermo electric power of Cu2S thin film was obtained and the seeback is positive refers to a p-type semiconducting. The calculated rectification ratio at 1 volt for the investigated device was found to be 4.3 at room temperature. I-V characteristic in dark at temperature from 393 to 373 Kelvin has been investigated. I-V characteristic in illumination at light intensity from 1400 to 22000 Lux has been investigated by change the distance between the light source and the sample. The I-V curves exhibited diode like behavior the obtained value of series resistance (Rs) was 104KΩ. The quality factor shows that the thermionic emission is the operating mechanism.

HTML

 

LAYING-DOWN CONFIGURATION OF 4,4”DIAMINOP- TERPHENYL ON SI(001)-2×1 OBSERVED BY SCANNING TUNNELING MICROSCOPY

U+1F5122016-12-17
Amer Mahmoud Amer Hassan, Akira Sasahara, Hideyuki Murata, Masahiko Tomitori

To fabricate ordered molecular multi-layers over a wide area through π–π stacking interaction, the molecule frameworks lying-down parallel to the substrate are preferable specially for the light-emitting and photovoltaic molecular devices. The lying-down configuration in the layers is mostly dominated by the chemical properties at the interface between the substrate and the first layer molecules. For example, as a substrate, a Si(001)-2×1 surface has a large number of Si dangling bonds per unit area. The molecules with π orbitals deposited on the Si(001)-2×1 can be bonded with the dangling bonds, which are slant to the surface, possibly leading to their lying-down configuration. In this study, we examine the adsorption of 4,4”diamino-pterphenyl (DAT) vapor-deposited on the Si(001)-2×1 by a scanning tunneling microscope (STM) to pursue the stable lying-down configuration. An ultrahigh vacuum (UHV) chamber system equipped with a molecule evaporator and STM was used. At low coverages of DAT, a number of elongated protrusions were observed, frequently tilted at ~17° to the Si dimer rows of the Si(001)- 2×1. The protrusions corresponded to individual DAT molecules. The stability at 17° was ascribed to three chemical bonds to the Si surface; each amino group at both ends of a DAT covalently bonds to one Si atom of a Si dimer, and in addition the center benzene ring of the DAT forms a bond, resulted in a butterfly-like lying down structure (Fig. 1) [1].

References 1) A. Hassan, T. Nishimura, A. Sasahara, H. Murata, and M. Tomitori: Surf. Sci. 630 (2014) 96.

HTML

 

PHYSICO MECHANICAL PROPERTIES OF AG DOPED NANO HYDROXYAPATITE/CHITOSAN

U+1F5122016-12-17
S. F. Mansour a, S. I. El-dekb, M. K. Ahmed c

Nano-hydroxyapatite/chitosan (n-HAP/CS) biocomposites with high compressive strength were synthesized by microwave coprecipitation assisted. HAP was doped with both Mg2+ and Ag+ simultaneously as the formula: [MgxAgyCa(10-x-y)(PO4)(OH)2] ;[0≤(x+y)≤1]. The samples were characterized by Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The results showed that the shape, size and crystallinity index of nano-HAP crystals in composites were similar to that of natural bone. Ag+ presents high impact in improving anti-bacterial effect, in addition; Mg2+dopant was a crucial factor in progressing the mechanical properties. Furthermore, mechanical testing exhibited that the maximum compressive strength of the composite materials was 15 MPa. The measured density was in range of 1.12-1.43 g/cm3. Multifunctional non-sintered materials show promising results in drug loaded bioceramics with improved mechanical features in bone tissue engineering.

HTML

 

PBS QUANTUM DOTS: THIN FILM APPLICATION IN OPTOELECTRONICS

U+1F5122016-12-17
Shaimaa A. Mohamed

Semiconductor nanocrystal represents an attractive alternative to various vacuum-based techniques for application in optoelectronic devices. Lead sulfide is used as colloidal quantum dots (CQDs) to benefit from their size tunability, stability, solution processability and high quantum yield luminescence. These properties allow more photon harvesting by matching the band gap to the solar spectrum, making it a versatile absorber material when applied in solar cell devices allow achievingpower-conversion efficiencies (PCEs) greater than 11%.The full potential of colloidal quantum dots is not fully harnessed yet. The thin film properties of the colloidal quantum dots are still limiting the performance of the device although it applies the optimum device engineering. Therefor it is important to overcome the exciting limit by understanding the thin film in more details. Since few people know about the technology, it is essential that we raise its profile.

Reference: 1. Philipp Stadler, Shaimaa A. Mohamed, et. al.Iodide-Capped PbS Quantum Dots: Full Optical Characterization of a Versatile Absorber, Adv. Mater. 2015, DOI: 10.1002/adma.201404921

HTML

 

PHYSICO MECHANICAL PROPERTIES OF AG DOPED NANO HYDROXYAPATITE/CHITOSAN

U+1F5122016-12-17
S. F. Mansour a, S. I. El-dekb, M. K. Ahmed c

Nano-hydroxyapatite/chitosan (n-HAP/CS) biocomposites with high compressive strength were synthesized by microwave coprecipitation assisted. HAP was doped with both Mg2+ and Ag+ simultaneously as the formula: [MgxAgyCa(10-x-y)(PO4)(OH)2] ;[0≤(x+y)≤1]. The samples were characterized by Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). The results showed that the shape, size and crystallinity index of nano-HAP crystals in composites were similar to that of natural bone. Ag+ presents high impact in improving anti-bacterial effect, in addition; Mg2+dopant was a crucial factor in progressing the mechanical properties. Furthermore, mechanical testing exhibited that the maximum compressive strength of the composite materials was 15 MPa. The measured density was in range of 1.12-1.43 g/cm3. Multifunctional non-sintered materials show promising results in drug loaded bioceramics with improved mechanical features in bone tissue engineering.

HTML

 

PBS QUANTUM DOTS: THIN FILM APPLICATION IN OPTOELECTRONICS

U+1F5122016-12-17
Shaimaa A. Mohamed

Semiconductor nanocrystal represents an attractive alternative to various vacuum-based techniques for application in optoelectronic devices. Lead sulfide is used as colloidal quantum dots (CQDs) to benefit from their size tunability, stability, solution processability and high quantum yield luminescence. These properties allow more photon harvesting by matching the band gap to the solar spectrum, making it a versatile absorber material when applied in solar cell devices allow achievingpower-conversion efficiencies (PCEs) greater than 11%.The full potential of colloidal quantum dots is not fully harnessed yet. The thin film properties of the colloidal quantum dots are still limiting the performance of the device although it applies the optimum device engineering. Therefor it is important to overcome the exciting limit by understanding the thin film in more details. Since few people know about the technology, it is essential that we raise its profile.

Reference: 1. Philipp Stadler, Shaimaa A. Mohamed, et. al.Iodide-Capped PbS Quantum Dots: Full Optical Characterization of a Versatile Absorber, Adv. Mater. 2015, DOI: 10.1002/adma.201404921

HTML

 

Improvement of physical properties of Cobalt nanoferrites via Gd/Er doping

U+1F5122016-12-17
Ebtesam E. Ateia, and Fatma S. Soliman

Pure nanoparticles of the rare-earth substituted cobalt ferrites with general formula CoGd0.025Er0.05 Fe1.925 O4were prepared by thechemical citrate method.The effect of variation in the rare-earth substitution and its impact on the structural characteristics, magnetic properties like saturation magnetization, coercivity and Curie temperature were studied.The average crystallite sizes of doped and pure Cobalt ferrite samples are21.49 and 37.7 nm respectively. The substitution of rare-earth elements in cobalt ferrite is promising for their magneto-optical recording application as they are helpful in decreasing the particles size of the investigated samples [1].Also theyalter the coercivity and saturation magnetization compared to pure cobalt nanoferrite [Fig.1].This can be clarified in view of weaker nature of the RE3+- Fe3+ interaction compared to Fe3+-Fe3+ interaction.EDAX spectra reveal the purity of the nano ferrite samples. The obtained data from EDAX elemental analysis is shown as inset of the figure. It can be seen that the stoichiometry is very close to the estimated values [Fig.2]. [1]Y. B. Kannan, R. Saravanan, N. Srinivasan, K. Praveena, K. Sadhana, J Mater Sci: Mater Electron (2016) 27:12000–12008

HTML

 

Physical Properties of Mg0.7Cu0.3Fe2O4Nano- Ferrites Synthesized by citrate method

U+1F5122016-12-17
Ebtesam E. Ateia, and Amira T. Mohamed*

Copper ferrite has beenstudied due to its motivating crystallographic and optical properties.Nanoferrites of the general formula Mg0.7Cu0.3Fe2O4were prepared by Citrate- gel auto combustion method. The structure was studied by X-ray diffraction, Brunauer- Emmet-Teller, and Energy dispersive X-ray spectroscopy analyses. The crystallite size was estimated from XRD broadening of (311) peak using Scherer’s formula(Fig.1).The magnetic properties werestudied by carrying out the hysteresis of Mg0.7Cu0.3Fe2O4at different temperatures (100,170,240and 300K) (Fig.2). The investigated samples exhibit low coercivity values indicating that the samples belong to the family of soft ferrites. The magnetization of all samples increases linearly with increasing applied magnetic field up to 5000 Oe. Beyond this applied field, the magnetization attained maximum values and then saturation occured.The band gap energy, which wascalculated from near infrared (NIR) and visible (VIS) reflectance spectra using the Kubelka-Munk function,decreases with increasing the particle size[1]. Furthermore, the band gaps are quite narrow (1.3–1.9eV), hence the investigated samples could act as visible light driven photo catalysts.

[1] M.A. Amer, T. Meaz, M. Yehia, S.S. Attalah, F. Fakhry, Alloys. Compd. 633, 448–455(2015).

HTML

 

STUDY OF THE ELECTRICAL PROPERTIES AND THE MICROSTRUCTURE OF ZnO DOPED WITH CuO AND Na3BiO3

U+1F5122016-12-17
M. M. Saadeldin1, Osama A. Desouky2, Mai M. Younis3, and Marwan M. Ahmed4

Mixtures of ZnO doped with CuO and Na3BiO3 as additive were prepared by solid state reaction from the calcined oxides. SEM and AFM revealed the presence of inter-granular phase. Additives present in grain boundaries between ZnO grains.XRD showed that no binary compound was formed and there are increase in dislocation density with additives. The conductivity and the dielectric constant are highly dependent on the microstructure of conducting grains surrounded by this insulating oxide barrier. The amounts of additives affect the coefficient of non-linearity and breakdown voltage. Microstructure had been studied with SEM and AFM.

HTML

 

Study The Genetoxicity Of Gold Magneto Nanoparticles In Liver Cancer Cells Via Laser Induced Plasma Spectroscopy

U+1F5122016-12-17
Ola S. Ahmed1 , H. Imam 2, Abdel-Rahman Zekri3Mona B. Mohamed2, Hussein M Khaled1 Mahmoud H Abdel-kader2,4

Laser-induced breakdown spectroscopy technique (LIBS) used in the study the effect of gold magneto nanoparticles on the liver cancer cells (HepG2) by examining the variation in genotoxicity and cytotoxicity.HepG2 cell line (106 cells) was cultured and expanded, after which, they were incubated with gold magneto nanoparticles at concentrations 10,25, 50 μg/ml at 12 hours. The effect of this nanoparticles in cell apoptosis as well as in autophagy were evaluated by both flow cytometry and acridine orange.Annexin V/propidium iodide double staining for evaluation of apoptosis in the treated cells at concentration of nanocomposite 10, 25, 50μg/ml showed increase in the apoptotic presented from 11.25% ± 3.1% to 28% ± 2.04%,39% ± 3.6%, 60% ± 4.3% respectively.The gene expression of apoptosis pathway was also investigated by apoptosis specific PCR array assay.The genes most high significantly in HepG2 cells were TNF, BIRC3 and NFKB1 fold regulation ratio of 158.03- fold and 149.2- fold. These genes expression profiles related to stress and toxicity pathways.LIBS results shows that increasing iron oxide nanoparticles concentration is associated with increasing calcium concentration in the biological cells. This effect might be due to increasing the probability of a calcium influx in single cells due to higher surface iron oxide loading and the degree of cell spreading.An increase in the calcium content in the cells have a role in program cell death was prove it by profile apoptosis PCR array.Finally we have demonstrated successfully that LIBS can be an effective technique for the detection of magnetic nanoparticles concentrations present in liver cancer cells (HepG2 cells) and study the effect of these particle through investigation variation in genotoxicity and cytotoxicity.

HTML

 

STUDY OF THE ELECTRICAL PROPERTIES AND THE MICROSTRUCTURE OF ZnO DOPED WITH CuO AND Na3BiO3

U+1F5122016-12-17
M. M. Saadeldin1, Osama A. Desouky2, Mai M. Younis3, and Marwan M. Ahmed4

Mixtures of ZnO doped with CuO and Na3BiO3 as additive were prepared by solid state reaction from the calcined oxides. SEM and AFM revealed the presence of inter-granular phase. Additives present in grain boundaries between ZnO grains.XRD showed that no binary compound was formed and there are increase in dislocation density with additives. The conductivity and the dielectric constant are highly dependent on the microstructure of conducting grains surrounded by this insulating oxide barrier. The amounts of additives affect the coefficient of non-linearity and breakdown voltage. Microstructure had been studied with SEM and AFM.

HTML

 

Study The Genetoxicity Of Gold Magneto Nanoparticles In Liver Cancer Cells Via Laser Induced Plasma Spectroscopy

U+1F5122016-12-17
Ola S. Ahmed1 , H. Imam 2, Abdel-Rahman Zekri3Mona B. Mohamed2, Hussein M Khaled1 Mahmoud H Abdel-kader2,4

Laser-induced breakdown spectroscopy technique (LIBS) used in the study the effect of gold magneto nanoparticles on the liver cancer cells (HepG2) by examining the variation in genotoxicity and cytotoxicity.HepG2 cell line (106 cells) was cultured and expanded, after which, they were incubated with gold magneto nanoparticles at concentrations 10,25, 50 μg/ml at 12 hours. The effect of this nanoparticles in cell apoptosis as well as in autophagy were evaluated by both flow cytometry and acridine orange.Annexin V/propidium iodide double staining for evaluation of apoptosis in the treated cells at concentration of nanocomposite 10, 25, 50μg/ml showed increase in the apoptotic presented from 11.25% ± 3.1% to 28% ± 2.04%,39% ± 3.6%, 60% ± 4.3% respectively.The gene expression of apoptosis pathway was also investigated by apoptosis specific PCR array assay.The genes most high significantly in HepG2 cells were TNF, BIRC3 and NFKB1 fold regulation ratio of 158.03- fold and 149.2- fold. These genes expression profiles related to stress and toxicity pathways.LIBS results shows that increasing iron oxide nanoparticles concentration is associated with increasing calcium concentration in the biological cells. This effect might be due to increasing the probability of a calcium influx in single cells due to higher surface iron oxide loading and the degree of cell spreading.An increase in the calcium content in the cells have a role in program cell death was prove it by profile apoptosis PCR array.Finally we have demonstrated successfully that LIBS can be an effective technique for the detection of magnetic nanoparticles concentrations present in liver cancer cells (HepG2 cells) and study the effect of these particle through investigation variation in genotoxicity and cytotoxicity.

HTML

 

Nanomaterial Enhanced Emission using Laser Induced Plasma Technique

U+1F5122016-12-17
A. M. EL Sherbini

It was the first worldwide published article about enhancing the amount of light emitted from nanomaterial target based plasma over corresponding bulk material. Both plasmas are created via interaction of Nd: YAG laser pulses under the same ambient conditions [1]. This subject become world-wide-spreading issue [2-8] and was subjected to extensive experimental study using OES-Technique. The effect of different experimental parameters including laser irradiance (fluence), delay time, different laser wavelengths and different types and sizes of nanomaterials were studied over the past five years in different laboratories. After all, some conclusions were drawn: (1) The enhanced emission was found increases linearly with delay time after plasma ignition, (2) Decreases in a logarithmic way with the increasing laser fluence, (3) No changes in both of plasma electron density and temperature from nano-tobulk materials (4) This enhancement emission was found compatible with relative masses ejected from either target and finally (5) The recently published work shows that the main reason of signal enhancement can be attributed to the a significant reduction of plasma threshold fluence offered by the nanomaterial size reduction. In this review we will explore different experimental and theoretical aspects of this new phenomenon.

[1] A.M. EL Sherbini, C.G. Parigger, Wavelength dependency and threshold measurements for nanoparticleenhanced laser-induced breakdown spectroscopy, Spectrochim. Acta B 116 (2016) 8–15 [2] A.M. EL Sherbini, A.-N.M. Aboulfotouh, F. Rashid, S. Allam, T.A. EL Dakrouri, Observed enhancement in LIBS signals from nano vs. bulk ZnO targets: comparative study of plasma parameters, World J. Nanosci. Eng. 2 (2012) 181–188. [3] A.M. EL Sherbini, A.A. Galil, T.M. EL Sherbini, Nanomaterials induced plasma spectroscopy, J. Phys. Conf. Ser. 548 (2014) 012031 [4] A. De Giacomo, R. Gaudiuso, C. Koral, M. Dell’Aglio, O. De Pascale, Nanoparticleenhanced laserinduced breakdown spectroscopy of metallic samples, Anal. Chem. 85 (2013) 10180–10187. http://dx.doi.org/10.1021/ac4016165. [5] A. De Giacomo, R. Gaudiuso, C. Koral, M. Dell’Aglio, O. De Pascale, Nanoparticle enhanced laser induced breakdown spectroscopy: effect of nanoparticles deposited on sample surface on laser ablation and plasma emission, Spec. [6] A.M. EL Sherbini, C.G. Parigger, “Nano-material size dependent laser-plasma thresholds,” Spectrochim. Acta Part B 124, 79–81 (2016).

HTML

 

PREPARATION AND CHARATERIZATION OF SOME SMART MATERIALS USING SPECIALLY DESIGNED ROBOTIC SYSTEM

U+1F5122016-12-17
Shereef A. Fareeda, Prof. Amer Mahmoud Amerb

The aim of the present work is to synthesis new magnetocaloric, magnetoelectric, piezoelectric and photochromic smart materials with improving the preparation conditions. It is well known; that Smart materials are designed materials that have a change in one or more properties in response to external stimuli. A second generation of specially machine with articulated robotic arm designed to prepare the samples with accurate physical parameters such as heating/cooling temperature, pressure, pH value and time of process. In addition, the system used to characterize the samples by measuring some of the thermal, magnetic, electrical, optical and mechanical properties.

HTML

 

NONLINEAR OPTICS & LASERS

U+1F5122016-12-17
Walid Tawfik

National Institute of Laser NILES, Cairo University, Cairo, Egypt.Nonlinear optics is the branch in physics in which the electric polarization density of the medium is considered as a nonlinear relation with the electromagnetic field of the light. As a widespread field of applications in electromagnetic wave propagation, light nonlinear-interaction with matter leads to a wide range of phenomena, like phase conjugation, Raman scattering and optical frequency conversion. The nonlinearity is usually obtained only at very high light intensities values of the electric field analogous to interatomic electric fields, approximately around 108 V/m, which is over than million suns, so that such intensities can be delivered only by lasers. Moreover, a variety of the analytical tools considered in nonlinear optics are of wide-ranging character, such as the symmetry considerations and perturbative techniques, and can similarly well be considered in other branches in nonlinear dynamics. Consequently, numerous developments in nonlinear optics have been made, with a lot of efforts with fields of, for example, laser and maser in 1960s and 1970s. Nonlinear optics clarifies nonlinear response of properties such as polarization, frequency, phase or path of incident light. These nonlinear interactions induce optical nonlinear phenomena: second harmonic generation SHG, third harmonic generation THG and Sum-frequency generation SFG. These phenomena due to nonlinear propagation of high intensity laser light in some crystals will be discussed and its applications will be considered.

HTML

 

FOUR-DIMENSIONAL ULTRAFAST ELECTRON MICROSCOPY (4D UEM)

U+1F5122016-12-17
Mohamed Mahgoob

The four-dimensional ultrafast electron microscopy (4D UEM) is a cutting-edge technique which has become a promising tool for visualizing atomic-scale motions in all four dimensions of space and time, aiming to image the electron dynamics in real-time scale. In this talk I will describe the four-dimensional ultrafast electron microscopy (4D UEM) developed at Caltech, which resulted in a number of patents and publications by Dr. Zewail as well as summarizing applications that investigate ultrafast phenomena with the time scale of a millionth of a billionth of a second, the femtosecond which is pivotal to understanding the dynamic processes of nano-objects. In particular, I will describe the photon-induced near-field electron microscopy (PINEM) allowing us to observe the Plasmon fields of nanoparticle via the measurement of photon-electron interaction. I will also present the latest developments in preparing the proper infrastructure and setting up the 4D UEM that will be operational next year and will be part of Zewail City’s facilities in imaging and nanotechnology.

HTML

 

SOLAR ENERGY: THE ULTIMATE RENEWABLE RESOURCE

U+1F5122016-12-17
Lotfia El Nadi1,2, Samah Mohamed 2 , Hossam Hamed1, Adel Shehap1, Magdy Omar1, Galila Mehana1, Hussein Abdel Moniem1, Laila Soliman3, Mahmoud Hafez3

Argument that sun provides power only during the day is countered by the fact that 70% of energy demand is during daytime hours. At night, traditional methods can be used to generate the electricity. Goal is to decrease our dependence on fossil fuels. Currently, 75% of our electrical power is generated by coal-burning and nuclear power plants.Mitigates the effects of acid rain, carbon dioxide, and other impacts of burning coal and counters risks associated with nuclear energy. pollution free, indefinitely sustainable.  CAIRO UNIVERSITY PROJECT WILL BE DEMONSTRATED.  NEW APPROACH TO APPLY REFRACTION OF LIGHT ON TRANSPARENT SPHERES WILL BE EXPLAIND and ADOPTED INDUSTRIALLY AND SCIENTIFICALLY

HTML

 

المجھر الالكتروني رباعي الابعاد فائق السرعة

U+1F5122016-12-17
محمد محجوب

یعتبر المجھر الالكتروني رباعي الابعاد فائق السرعة تقنیة متطورة, والتي اصبحت اداة واعدة لدراسة الحركة على المستوي الذري في الابعاد المكانیة والزمانیة, ویھدف لتصویر حركیات الالكترون آنیا. خلال كلمتي, سوف اقوم بوصف المجھر الالكتروني رباعي الابعاد والذي تم تطویره بمعھد كالیفورنیا للتكنولوجیا, والذي اسفر عن عدد من براءات الاختراع بالاضافة لعدد من الابحاث للدكتور احمد زویل –رحمھ الله- كما سأتحدث عن ملخص لتطبیقاتھ في دراسة الظواھر فائقة السرعة والتي تحدث في نطاق ملیون ملیار جزء من الثانیة والمعروفة بالفتموثانیة (عشرة مرفوعة للقوة - ١٥ ), والتي تعتبر محوریة في عملیة دراسة حركیات الاجسام متناھیة الصغر. وعلى وجھ الخصوص, سأقوم بالحدیث عن المجھر الالكتروني ذو الحقل القریب المستحث بالفوتونات, الذي یسمح لنا بمراقبة الحقول البلازمونیة للجسیمات متناھیة الصغر من خلال قیاس تفاعل الفوتون والالكترون. سأقدم كذلك آخر التطورات في اعداد البنیة التحیة المناسبة للمجھر الالكتروني رباعي الابعاد بالاضافة لاعداده للتشغیل في العام المقبل, وسیكون جزءا من مرافق مدینة زویل للتصویر وتكنولوجیا النانو.

HTML

 

SOLAR ENERGY: THE ULTIMATE RENEWABLE RESOURCE

U+1F5122016-12-17
Lotfia El Nadi1,2, Samah Mohamed 2 , Hossam Hamed1, Adel Shehap1, Magdy Omar1, Galila Mehana1, Hussein Abdel Moniem1, Laila Soliman3, Mahmoud Hafez3

Argument that sun provides power only during the day is countered by the fact that 70% of energy demand is during daytime hours. At night, traditional methods can be used to generate the electricity. Goal is to decrease our dependence on fossil fuels. Currently, 75% of our electrical power is generated by coal-burning and nuclear power plants.Mitigates the effects of acid rain, carbon dioxide, and other impacts of burning coal and counters risks associated with nuclear energy. pollution free, indefinitely sustainable.

* CAIRO UNIVERSITY PROJECT WILL BE DEMONSTRATED. * NEW APPROACH TO APPLY REFRACTION OF LIGHT ON TRANSPARENT SPHERES WILL BE EXPLAIND and ADOPTED INDUSTRIALLY AND SCIENTIFICALLY

HTML

 

المجھر الالكتروني رباعي الابعاد فائق السرعة

U+1F5122016-12-17
محمد محجوب

یعتبر المجھر الالكتروني رباعي الابعاد فائق السرعة تقنیة متطورة, والتي اصبحت اداة واعدة لدراسة الحركة على المستوي الذري في الابعاد المكانیة والزمانیة, ویھدف لتصویر حركیات الالكترون آنیا. خلال كلمتي, سوف اقوم بوصف المجھر الالكتروني رباعي الابعاد والذي تم تطویره بمعھد كالیفورنیا للتكنولوجیا, والذي اسفر عن عدد من براءات الاختراع بالاضافة لعدد من الابحاث للدكتور احمد زویل –رحمھ الله- كما سأتحدث عن ملخص لتطبیقاتھ في دراسة الظواھر فائقة السرعة والتي تحدث في نطاق ملیون ملیار جزء من الثانیة والمعروفة بالفتموثانیة (عشرة مرفوعة للقوة - ١٥ ), والتي تعتبر محوریة في عملیة دراسة حركیات الاجسام متناھیة الصغر. وعلى وجھ الخصوص, سأقوم بالحدیث عن المجھر الالكتروني ذو الحقل القریب المستحث بالفوتونات, الذي یسمح لنا بمراقبة الحقول البلازمونیة للجسیمات متناھیة الصغر من خلال قیاس تفاعل الفوتون والالكترون. سأقدم كذلك آخر التطورات في اعداد البنیة التحیة المناسبة للمجھر الالكتروني رباعي الابعاد بالاضافة لاعداده للتشغیل في العام المقبل, وسیكون جزءا من مرافق مدینة زویل للتصویر وتكنولوجیا النانو.

HTML

 

New Retinal Image Processing Trends to Assist the Early Detection of Diabetic Retinopathy

U+1F5122016-12-17
A.K.M. Seyam, A.A. Sharawi1, A.A. Eldib2

Early detection of diabetic lesions can halt progression of the disease and prevent consequent loss of vision, as exudates are a visible sign of diabetic retinopathy and a marker for the presence of coexistent retinal oedema. If present in the macular area, they are a major cause of treatable visual loss in the non proliferative forms of diabetic retinopathy. It would be useful to have an automated method of detecting exudates in digital retinal images produced from diabetic retinopathy screening programmes In this work we apply digital image processing techniques to detect the main anatomical features of the retina, and to extract diabetic retinopathy signs from retinal images. Various approaches are explored to localize the optic disc. First template matching is implemented. Then we use texture analysis combined with morphological operations and markercontrolled watershed to localize the optic disc and its boundary. Once the optic disc has been located, a Region-of-Interest (ROI) for the macular region is created. Then the macula and fovea are segmented. We have proposed various techniques to detect exudates, hemorrhages and microaneurysms by morphological operations combined with Otsu’s thresholding algorithm and FCM clustering. The methodologies are tested on a set of 130 images. The success rates of disk localization by template matching and morphological operations are 94.6%, and 96.9% respectively, and 92% for the macular region. It is also found that the proposed method for exudates detection by morphological operations detects exudates successfully with sensitivity, specificity, and accuracy of 80.19 %, 98.85%, and 98.72 % respectively.

HTML

 

Particle Production in 3.7A GeV 16O–Nucleus Interactions

U+1F5122016-12-17
A. Abdelsalam1*, M. S. El–Nagdy2*, B. M. Badawy3*, W. Osman1*, Mennah1*, Abdelnasser4*, and Mariem2

Experimental study on 3.7A GeV 16O interactions with emulsion nuclei is carried out. The shower particle multiplicity characteristics are investigated. Data are presented in terms of the number of emitted particles in both forward and backward angular zones. The dependence on the target size is presented. For this purpose the statistical events are discriminated into groups according to the interactions with H, CNO, Em, and AgBr target nuclei. The separation of events, into the mentioned groups, is executed basing on Glauber's multiple scattering theory approaches. Features suggestive of a decay mechanism seem to be a characteristic of the backward emission. This emission may be during the de–excitation of the excited target nucleus, in a behavior like that of compound–nucleus disintegration. Regarding the limiting fragmentation hypothesis beyond 1A GeV, the target size is the main parameter affecting the backward production. The incident energy is a principle factor responsible for the forward emitted particle production in a creation system. However, the target size is an effective parameter as well as the projectile size considering the geometrical concept regarded in the nuclear fireball model. The data are simulated in the framework of the Lund Monte Carlo simulation code, the so–called modified FRITIOF model. The multisource thermal model can predict source numbers, may be responsible for particle production.

HTML

 

Angular Distributions of Target Fragments Emitted in 14.6 A GeV Silicon-Emulsion Interactions

U+1F5122016-12-17
A. Abdelsalam1, M.S. El–Nagdy2, A.M. Abdalla3, A. Saber3

Many results obtained from studying the angular distributions of heavy fragments emitted from interaction of silicon nucleus with composite target nuclei of emulsion at collision energy 14.6 A GeV per nucleon. The angular distributions of grey and black secondary charged produced fragments are well described through statistical model. The average emission angle is for grey particles and for black particles that are nearly constant for different projectiles in range of collision energy 2.2 to 14.6 A GeV. The predicted rational velocity by statistical model which describe the system responsible for production of secondary particle is nearly equal to 0.5 for grey particles and tends to be ~ 0.13 for black particles. The velocity of the emitting system described by parameter β//, where the emitting system for grey particles is fast with typical longitudinal velocities β// g ~ 0.13-0.20 while it slow for emission black particle in the range β// b ~ 0.008-0.019. The temperatures of the system responsible for emission of secondary slow fragments are found to be 58 and 6 MeV for fast grey and slow heavy fragments respectively. The angular distributions of slow fragments, grey and black particles show clear dependence on size of target nucleus. Most probable emission angles are in forward direction for interactions with light nuclei while it becomes symmetry around the middle angle for interactions with heavy nuclei. The emission system of these particles becomes slower and low temperature with increasing mass number of the interacting target nucleus.

HTML

 

Fragmentation of 16O projectile in Nuclear Emulsion at 60 GeV

U+1F5122016-12-17
M.S.ElNagdy1,A.Abdelsalam2,B.M.Badawy3,P.I.Zarubi4, A.M.Abdalla5, S.M.Abdel-Halim6, M.Mahmoud2, A.Saber5 and M.M.Ahmed1

Topology of 16O fragmentation at 4.5 A Gev/c with emulsion nuclei is reported. The charges Z2 of projectile fragments were carefully measured and identified.The experimental measurements of partial production cross-section of the multiple helium fragments emitted from 16O beam are studied and compared with that obtained from different projectiles and various energies. We present results using a special type of events,selected to separate the events due to collision of singly charged particle Z=1 from 16O compared with collision of neutron from 16O beam. Those when neutron from 16O is collided. We describe a topological structure of such events.

HTML

 

MASSES OF MESON SPECTRA IN POLYAKOV LINEAR-SIGMA MODEL IN VANISHING AND FINITE MAGNETIC FIELDS

U+1F5122016-12-17
Abdel Magied Abdel Aal DIAB 1,2, Abdel Nasser Tawfik 1,2 and M. T. Hussien 3

At vanishing temperature, the Ployakov linear-sigma model (PLSM) is considered in calculating sixteen meson states. Huge magnetic fields are likely in relativistic heavyion collisions due to offcenter opposite motion of the spectator charges and momentum imbalance of the participants. Influences of such magnetic fields can be integrated to the PLSM Lagrangian through a utilization of Landau quantization, a momentum-space dimensional reduction and a modification in the energy-momentum relation. We present a novel study for sixteen meson states, especially their masses, which shall be compared to the most recent compilation of the Particle Data Group, lattice QCD spectra and other models.

HTML

 

NATURE - INSPIRED: ALGORITHMS AND APPLICATIONS

U+1F5122016-12-17
Kornay Hameda

Nature is a wonderful source of inspiration for developing optimization techniques that can tackle difficult problems in science and engineering. Since the early 1970s, various nature-inspired optimization algorithms have emerged starting with the Genetic Algorithm (GA) have been proposed and successfully implemented in different applications. However, because each algorithm possesses strengths and weaknesses, there is no single method within the family of nature-inspired numerical optimization algorithms that stands out as the best for solving all types of problems. Therefore, hybrid algorithms have been presented to balance the overall exploration and exploitation ability to improve the convergence capability of the optimization techniques.

HTML

 

NEW TRENDS IN COMPUTATIONAL PLASMONIC

U+1F5122016-12-17
Ahmed Heikal

Center for Photonic and Smart Materials (CPMS), Zewail City of Science and Technology, Sheikh Zayed District, 6th of October City, 12588 Giza, Egypt. For any photonic device simulation, the accuracy of the numerical solution not only depends on the methods being used but also on the discretization parameters used in that numerical method. The analysis of optical waveguides with strong longitudinal and transverse discontinuities remains a defiance facing numerical techniques. In this work, three innovative methods will be presented to overcome some of the problems facing the traditional methods of modeling photonic devices, especially plasmonics. A new smoothed finite element method (SFEM) is proposed to analyse time domain wave propagation in photonic devices. Moreover, to accurately analyze plasmonic structures with strong discontinuities, a stable Bidirectional Beam Propagation Method (BiBPM) based on Blocked Schur (BS) algorithm is introduced. Finally, an accurate and computationally efficient rational Chebyshev multi-domain pseudospectral method (RC-MDPSM) for modal analysis of Photonic devices is presented. The efficiency of the suggested technique stems from using rational Chebyshev basis functions to accurately represent the semi-infinite computational domain; thus, eliminating the use of PML like absorbing boundary conditions.

HTML

 

ULF GOMAGNETIC PULSATIONS DRIVEN BY SOLAR WIND NUMBER DENSITY OSCILLATIONS

U+1F5122016-12-17
Rasha M Emara

The magnetosphere of the earth undergoes oscillations of different periods and amplitudes. There is almost consensus that the variations are of solar origin, while the earth’s main magnetic field and secular variations are of internal origin. The magnetospheric (ULF) pulsations can arise from a variety of sources, and these pulsations are often observed to occur at discrete frequencies over extended intervals of time. The free energy needed to stimulate such pulsations can arise from local reconfiguration of magnetic stresses, wave-particle interaction, or a host of other sources which are internal to the magnetosphere. In addition, the solar wind can often provide a source of broadband energy which can then couple to discrete magnetospheric oscillations. Knowing that the real solar wind is variable, impulsive compression arising from rapid increase of solar wind dynamic pressure requires changes of the plasma and field properties through the magnetosphere. The present work studies the source of magnetospheric ultra low frequency pulsation focusing on the solar wind dynamic pressure and solar wind number density as a direct driver of these pulsations. The correlation between the solar wind number density pulsations and the magnetospheric magnetic field oscillations was studied for 30 events (in the interval from January to June 2007). The spectral analysis of the solar wind number density and the geosynchronous magnetospheric data was also investigated for the same events. Both investigations revealed a strong relation between the global magnetospheric oscillations and the solar wind oscillations. Keywords: Magnetosphere, Magnetospheric oscillations, Solar wind , interplanetary magnetic field.

HTML

 

OMEGA TABLE AND PARTIAL MOLECULAR SYMMETRY SOLVE GROUP THEORY CHARACTER TABLE DEFECTS IN MOLECULAR SPECTROSCOPY

U+1F5122016-12-17
A. S. Abdel-Rahman1, S. K. Abdel-Aal

Group theory character table is a very useful tool to know important information about molecular activities and their spectra but suffers different defects such as the definition of the physical meaning of ω, the entire levels of degenerate states and the atomic motion through molecular vibration. On the way to define the infrared spectra, Raman spectra and natural frequency of molecules; it is important to split degenerate states and determine the motion of each atom through molecular vibration. While symmetry can be seen as the most basic and important concept in physics, higher n-fold rotation axis Cn symmetry element can be represented as full or partial symmetric rotation axis and governs other symmetry elements in the molecule thought the vibrational motion. Symmetry states and Omega-table which hold all possible symmetry states of the molecule will solve character table defects. Selection rules judge some of the symmetry states to be forbidden. Omega-table illustrates the relation between symmetry elements in the molecule through its translation, rotation and vibration processes and separates the degenerate states and then can be reduced to point group character table. Based on omega-table, the description of the atomic motion of NH3 molecule or any other molecules through vibration were so clear according to ω mathematical value and its physical meaning.

HTML

 

MEASUREMENT OF SOUND REDUCTION INDEX OF LIGHTWEIGHT PARTITIONS USING TWO- ROOM AND VIBRATION VELOCITY METHODS

U+1F5122016-12-17
A.M.Shehap1, Abd ElFattah A Mahmoud2, Hatem Kh. Mohamed3*

Noise pollution has become another deleterious outcome of modern civilization. Nowadays, the usage of lightweight partitions in various wall and floor structures increases due to its advantages over traditional masonry partitions since they are easy to install and it can achieve the sound insulation requirements with low cost and low overall surface weight. Airborne sound insulation is the most important physical quantity defining the acoustical quality of buildings. In this paper, a comparison between two-room method that described by ISO 140-3 and vibration velocity method (not standardized) for measuring sound reduction index (SRI) of single and double leaf plywood and gypsum board lightweight partitions are presented. Regarding to double leaf partitions, measurements were carried out with the leaves separated by 50, 100 mm air gap. Space between the leaves was filled with a layer of either Rockwool or polyurethane in order to show the effect of cavity absorption on the sound reduction index behavior. From the results it is shown that, the SRI of gypsum board increased by 5-6 dB over plywood and it is also shown that a good agreement between the two mentioned methods except at high frequencies.

HTML

 

STUDYING THE CHARACTERISTICS OF THE INTERVAL BETWEEN ICME-SHOCK ARRIVAL TIMES

U+1F5122016-12-17
Rofida Saber1, Ramy Mawad2, Hussien M. Farid3, Shahinaz Yousef3

The estimation and characterizes of interval time between associated arrived Interplanetary Coronal Mass Ejection-Storm Sudden Commencement (ICME-SSC) events is the aim of this research. The travel time of the CME-Shock could be estimated from an empirical equation that depends on ICME's mass and velocity. It helps us to estimate the more accurate Coronal mass ejection's (CME) travel time reaching Earth. A high correlation was found between interval time and ICME's mass during the period 1996-2010.

HTML

 

IN THE NAME OF ALLAH, MOST BENEFICENT, THE MERCIFUL DARK MATTER, DARK ENERGY; A QURANIC PROSPECTIVE

U+1F5122016-12-17
Shahinaz Yousef

In The Name of Allah, Most Beneficent, The Merciful " He created the heavens without pillars that you see… sūratluq'mān 10 "Allah is He Who raised the heavens without pillars that you see…(The Thunder 13:2) These two verses of the Noble Quran clearly are taking about the invisible dark matter and dark energy respectively. They are both described as invisible pillars. However dark matter is used in the very creation of the cosmos while dark energy is used in raising up the cosmos. We can see only 4.9 of the cosmos. Dark matter is an unidentified type of matter comprising approximately 27% of the mass and energy in the observable universe. The function of dark matter can be referred from the rest of sūratluq'mān10th verse. He created the heavens without pillars that you see and has cast into the earth anchorage, lest it should shake with you.., In analogy we can infer that the function of dark matter is to stabilize the cosmos. Dark Energy cause accelerated expansion of the universe contrary to expectations.

HTML

 

ON THE SOLAR CORONAL HOLES PROTON AND ELECTRON STREAMS INITIATIONS OF CENTRAL ITALY AND NEW ZELANDSEVEREEARTHQUAKES IN OCTOBER AND NOVEMBER 2016

U+1F5122016-12-17
Shahinaz Yousef, Mohamed Ahmed Semeida and Sara Said Khodairy

As we are at the bottom of the very weak solar cycle number 24, the sun is dominated by very large coronal holes. The magnetic field lines of coronal holes are open, thus they are the sites of fast solar winds as protons and electrons can easily escape into space. Central Italy was struck by several earthquake starting 26 of October 2016 and ending 3 November. The largest was of magnitude 6.5 on October 30. A wide coronal hole in the solar northern solar hemisphere started facing the earth on October 26, enabling fast solar wind streams to strike the earth. Ground electric currents were recorded as a consequence of this coronal hole. The 2016 Kaikoura earthquake was a magnitude 7.8 (Mw) earthquake in the South Island of New Zealand that occurred two minutes after midnight on 14 November 2016. This earthquake can be attributed to another solar coronal hole located in the Solar Southern hemisphere. The mechanism of initiation of earthquakes due to solar streams is suggested as due to induced electric currents in the ground and magma below the surface that cause movements in the plates of the earth thus induce earthquakes.

HTML

 

CHARGING STRATEGY FOR ELECTROSTATIC CONTROL OF SPACECRAFT: NEW APPROACHES

U+1F5122016-12-17
Yehia Abdel-Aziz

Spacecraft charging is a naturally occurring phenomenon in the space plasma environment, which in most cases is undesirable due to the deleterious effect on on-board electronics. Based on the fundamental physical principle that a moving charged particle experiences the Lorentz force in a magnetic field, one can deduce that an electrostatically charged spacecraft in Earth orbit is subjected to the Lorentz force in the Earth’s magnetic field. Early studies of spacecraft charging conclude that the natural spacecraft charging level may reach to about 10-8 C/kg and the induced Lorentz force with such charging level is insufficient to perturb the orbit and attitude of satellite significantly. The concept of Lorentzaugmented orbits is analogous to the motion of charged dust grains in planetary magnetic fields, After the launch of artificial satellites, the phenomenon of spacecraft surface charging was discovered and found to be omnipresent, and therefore the motion of electrically charged artificial satellites affected by the Lorentz force. However, much research relating to charged spacecraft are conducted by space-plasma physicists, and the primary purpose of their research is to attenuate the hazardous electromagnetic radiation effect caused by surface charging. Contrary to previous studies that concentrate on passive mitigation of the charge, a new concept of active application of the charge of spacecraft has been proposed by Peck in recent years [1]. Such conception spacecraft is referred to as Lorentz spacecraft, an artificially charged space vehicle that intentionally generates net charge on its surface to induce Lorentz force via interaction with the planetary magnetic field. If the charging level is several orders of magnitude larger than natural charging level or even higher, the induced Lorentz force could be utilized as propellantless electromagnetic propulsion for orbital maneuvers and attitude control. The Lorentz force acting on an electrostatically charged spacecraft may provide a useful thrust for controlling a spacecraft’s orbit and attitude control [2]. In this work, the Lorentz force has been developed as a function of the orbital elements. The orbital perturbations of a charged spacecraft by Lorentz force in the Earth’s magnetic field, which is modeled as a titled dipole is investigated using the Gauss variation of the Lagrange planetary Equations. The perturbations in the orbital elements depend on the value of the charge to mass ratio (q/m). The dynamical models of the Relative motion are developed that leads to approximate analytical solutions for the motion of a charged spacecraft subject to Lorentz force. The modeled derived when the chief spacecraft’s reference orbit is either circular or elliptical, and the deputy spacecraft is capable of established electrostatic charge. The numerical results show that the effects of the Lorentz force on the spacecraft are to change intrack position or/and plane orbit. The results investigated the approximation of the trajectory an estimate the reachable of the Lorentz spacecraft for short time intervals with different ration (q/m) for different orbits in LEO.

[1] Peck MA. Prospects and challenges for Lorentz-augmen-ted orbits. In: AIAA guidance, navigation, and control conference and exhibit, San Francisco, California, 15–18 August 2005, paper no. IAA-2005-5995. [2] Abdel-Aziz, Yehiaand M. Shoaib, Attitude dynamics and control of spacecraft usinggeomagnetic Lorentz force. Research in Astronomy and Astrophysics (RAA) Vol 15 No. 1, 127-144, 2015.

HTML

 

HAMILTONIAN MODEL OF FORMATION FLYING SATELLITESINTHE NEAR-POLAR CIRCULAR ORBITS Shaheera A. Altalhi*1 and M.I. El-Saftawy*&**

U+1F5122016-12-17
*King Abdul-Aziz University, 21442 Jeddah, Saudi Arabia. **National Research Institute of Astronomy and Geophysics, 80203 Cairo, Egypt

HTML

 

ARCHAEOLOGICAL PROSPECTION VIA NEW CUCKOO SEARCH ALGORITHM

U+1F5122016-12-17
M. Abdelazeem1, E. Emary2, M. Elgayyar3 and N. Sweilam3

Geophysical tools are non-destructive techniques used normally to explore subsurface geologic structures and buried objects. The goal of geophysical inverse problem is to determine the spatial distribution and depths to buried targets at a variety of scales; it ranges from few centimeters to many kilometers. To identify ore bodies, extension of archaeological targets, old mines, unexploded ordnance (UXO) and oil traps, the linear geomagnetic/gravitational inverse problem resulted from the Fredholm integral equation of the first kind is solved using many strategies. The solution is usually affected by the condition of the kernel matrix of the linear system and the noise level in the data collected. In this paper, a regularized Kaczmarz method is used to get a regularized solution. This solution is taken as an initial solution to Cuckoo search global optimizer to refine the quality and reach a plausible model. The artificial intelligence methods are less sensitive to noise or ill-posedness. To test efficiency, the proposed hybrid method is applied to different synthetic examples of different noise levels and different dimensions. Then, to prove the applicability and reliability of the method, it is applied to different real archaeological sites.

HTML

 

EVOLUTION OF THE BINARY NEUTRON STAR SYSTEM PSR1913+16 DUE TO GRAVITATIONAL WAVES EMISSION

U+1F5122016-12-17
Zeinab A. Mabrouk, M. K. Ahmed, Shahinaz Yousef

We have applied the method derived by (Imshennik and Popov 1994) of determination the elliptical orbits evolution due to gravitational wave emission on PSR1913+16. Our results are highly comparable with the latest analysis of that system based on published timing observations from 1974 through 2006 (Weisberg, Nice and Taylor, 2010). The comparison is shown in the next table. We plan to extend the system data analysis up till 2016.

Imshennik V.S. and Popov D.V., 1994. Astronomy Letters, Vol.20, No.5, 1994, PP.529-537.
Weisberg J. M., Nice D. J. and Taylor J. H., 2010. The Astrophysical Journal, 722:1030–1034.

HTML

 

Tissue Engineered Hearts

U+1F5122016-12-17
Amr Zaher

Heart failure occurs when the heart is unable to pump sufficiently to maintain blood flow to meet the body's needs. The annual incidence approaches 10 per 1,000 population after 65 years of age, affecting people of all ages, from children and young adults to the middle-aged and the elderly. Heart failure is present in 2 percent of person's age 40 to 59 and more than 5 percent of persons age 60 to 69. In the case of heart failure that does not respond to medical treatments, hearts transplant the treatment of choice. Rejection is most likely to occur after the transplant. Patients need to take medicines for the rest their life to suppress the immune system. These medicines increase the chance for infection. Their long-term use also can increase risk for cancer and renal failure. The developing field of tissue engineering aims to regenerate damaged tissues by combining cells from the body with highly porous scaffold biomaterials, which act as templates for tissue regeneration, to guide the growth of new tissue. Engineer entire new hearts, will enable transplants without the risk of rejection by the recipient's immune system. The strategy is simple enough in principle. First we remove all the cells from animal heart then take the scaffold left behind and repopulate it with stem cells immunologically matched to the patient in need. The crippling shortage of transplantable hearts around the world may be solved.

HTML

 

EFFECT OF COLD PLASMA ON THE BILAYER LIPID MEMBRANE

U+1F5122016-12-17
Heba M Fahmy, Asmaa A Hassan, Ghada F Abdelfatah, Salma Y Mohamed1, Mohamed H Gaber

Cold atmospheric plasma (CAP) has many promising applications in biomedical engineering, dentistry and oncology. This study investigates the effect of CAP on 1,2-dipalmitoyl-Sn-glycerol-3- phosphocholine (DPPC) liposomes prepared by the thin film hydration method which are used as a model for lipid bilayer membrane. DPPC liposomes were exposed to cold plasma 2, 3 and 5 minutes. The effects of cold plasma on DPPC characterization parameters such as size, charge, FTIR absorption spectrum, UV-visible spectrum and phase transition temperatures were investigated. Exposure of DPPC liposomes to CAP led to an increment in the size and stability of liposomes by increasing the exposure time. 2-min CAP exposure was found to increase liposomal size through particle aggregation, whereas, 3 and 5 min exposure increases the liposome size via adsorption of negative species emerging from CAP on their surfaces. As depicted from differential scanning calorimetry (DSC) results, the electrostatic interaction between the CAP species and phospholipids acyl groups of DPPC resulted in the change of DPPC conformation. The hydrocarbon chains of lipid molecules arranged more closer, especially with increasing the exposure time. Thus, it can be concluded that CAP alters the physical and chemical characteristics of DPPC liposomes.

HTML

 

PREPARATION, CHARACTERIZATION AND IN VITRO ANTIMICROBIAL ACTIVITY OF LIPOSOMAL THYMOQUINONE AGAINST DIFFERENT MICROORGANISMS

U+1F5122016-12-17
Heba Mohamed Fahmy, Nada Reda Abd Elkader, Taiseer Mohamed Abd Eldaim, Omnia Eid Ali, Ayaat Mahmoud Mosleh, Latifa Helmy Ahmed

Nowadays, infectious microorganisms show a significant tolerance and become more and more resistant to currently used antibiotics. The present study aims to evaluate the effect of Thymoquinone (TQ) (The main gradient of Nigella sativa seeds) either free or encapsulated in (1,2-dipalmitoyl-Sn-glycero-3- phosphocholine) DPPC liposomes on the antimicrobial activity of several microorganisms (Escherichia coli, Staphylococcus aureus, Candida albicans, Aspergillus brasiliensis). DPPC liposomes and TQ-encapsulated DPPC liposomes were characterized by the measurement of the liposomal size, zeta potential, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy, UVvisible spectrum, transmission electron microscope in addition to the measurement of the refractive index. The encapsulation efficiency of the TQ-encapsulated liposome was found to be more than 90%. The liposomal size of TQ-encapsulated DPPC liposomes showed an increase relative to DPPC liposomes. Moreover, the results obtained for the zeta potential (-17.7 mV for DPPC liposomes versus -7.06 mv for TQ-encapsulated DPPC liposomes) indicated that the DPPC had become less stable due to the TQ-DPPC encapsulation, meaning a loss of repulsive forces between particles and a higher tendency of aggregation. DSC results demonstrated a higher phase transition of TQ-encapsulated DPPC liposomes when compared to free DPPC lisposomes indicating that the hydrocarbon chains of lipid molecules arranged more closer due to TQ encapsulation. We also examined the antimicrobial activity of both free DPPC and TQ-encapsulated DPPC liposomes by the zone Inhibition method against several types of microorganisms. The antimicrobial action of both Escherichia coli, Staphylococcus aureus species were not changed by any of the tested formulation. Free thymoquinone showed a moderate antimicrobial activity on Candida albicans, however, neither DPPC nor TQ-encapsulated DPPC liposomes showed any effect on the same yeast species. Regarding the Aspergillus brasiliensis, it demonstrated a mild antimicrobial effect by both the DPPC and TQ-encapsulated DPPC Liposomes. In conclusion, encapsulation of DPPC liposomes with TQ greatly alter the physical and chemical properties of DPPC liposomes. TQ-encapsulated DPPC liposomes can be utilized as an antimicrobial agent against the Aspergillusbrasiliensis fungi.

HTML

 

OBSTACLES AND CHALLENGES IN THE TREATMENT OF BRAIN DISORDERS: EMERGING USE OF NANOTECHNOLOGY IN THE TREATMENT OF NEUROLOGICAL DISEASES

U+1F5122016-12-17
Heba M Fahmy

There is a widespread concern about neurological disorders. Unfortunately, most of the currently used treatment strategies for the handling of many of these disorders remain unsuccessful. In fact, drug delivery from the systemic circulation to the central nervous system (CNS) is restricted due to the presence of many extracellular and intracellular barriers. One promising solution to bypass these obstacles is by applying the drug delivery systems in the nanoscale dimensions. These nanosized drug delivery systems have many advantages over other conventional drug delivery methods such as: specific targeting, high drug loading capacity and in many cases, reduced toxicity. Grounded on this fact, nanotechnology could cause a revolution in the treatment of neurological and psychiatric diseases. In this context, I will start with the drawbacks of the currently used conventional drug delivery systems for the CNS and the challenges they affront to make their actions. Then, I will discuss the role of nanotechnology in enhancing the delivery of drugs to the CNS. I will present some examples of the effective use of nanoparticles in the handling of many brain disorders, especially: Alzheimer's disease, brain tumors and others. At the end, I will speak about the future use of nanotechnology in the advanced treatment of neurological diseases.

HTML

 

PREPARATION AND PHYSICOCHEMICAL CHARACTERIZATION OF (STARCH/CHITOSAN/GELATIN) GLYCEROL PLASTICIZER-BASED THIN FILMS

U+1F5122016-12-17
Heba Mohamed Fahmy, Ahmed Samir Mohamed, Merna Mostafa Abd El-Hamed, Amira Bahaa El-Din Mustafa, Amena Sayed Elfaky, Esraa Samy Abu Serea

widespread applications in diverse fields such as food packaging industries, wound dressings (artificial skin), tissue engineering, antibacterial agents and carriers in drug delivery/drug release systems especially anticancer drugs. In the present work, we geared up for the first time, Chistosan/starch/gelatin thin films using glycerol as a plasticizer. The current study introduces a comparison between three different concentrations of starch-Chitosan-gelatin blends (12.5:12.5:25) blend I, (15:15:20) blend II and (10:10:30) blend III while using glycerol as a plasticizer in all the blends. The characterizations of thin films were evaluated using X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Fourier Transform Infrared Spectroscopy (FTIR). In addition, mechanical properties measurements (tensile strength, elastic modulus and the elongation at break %) were performed. The results of the present study indicated that blend III (10:10:30) showed significant increases in the tensile strength, elastic modulus and the elongation at break% relative to the 2 other blends. These results pointed to better mechanical properties emphasized by blend III. XRD demonstrated the crystalline structure in the prepared thin films. In addition, FTIR showed that the three materials used (Chitosan, starch and gelatin) were well cross linked together which resulted in a homogeneous mixture. In conclusion, The present study presented a flexible blend (blend III) made of Stach/Chistosan/ gelatin with the ratios (10:10:30) with good mechanical properties that can be applied in various applications. Further studies are needed to test the engineered thin films created in the present work in diverse applications such as food packaging, skin compensators or others.

HTML

 

Evaluation of the efficiency of 99mTc-DMSA as a radiopharmaceutical in dynamic renal scans

U+1F5122016-12-17
Heba M Fahmy1*, Hossam M Yassin2, Islam M Muhamed1, Samar E Mohamed1, Shimaa S Hassan1

In dynamic renal scans, 99mTc-diethylenetriamine pentaacetic acid (DTPA) is much used and give information about the renal blood-flow and excretory function. 99mTc-dimercaptosuccinic acid (DMSA) is employed for static renal imaging and can show also the renal cortical structure. The purpose of this work was to evaluate whether DMSA can be utilized as a radiopharmaceutical in dynamic renal scans or not. The aim extends also to compare the results obtained from DMSA with those obtained with DTPA scans. A comparison of the data obtained from the renograms of 47 subjects (normal subjects and abnormal renal function patients having: obstructive nephropathy, bilateral nephropathy, hydro-nephrosis, reduced or non-function kidney and/or atrophic kidney) that had 99mTc-DMSA and 99mTc-DTPA dynamic scintigraphies using the same protocol. Estimation of the left kidney, right kidney and the total glomerular filtration rate (GFR) from 99mTc-DTPA and 99mTc-DMSA renograms showed a strong positive correlation.Moreover, estimation of the time of the peak height from 99mTc-DTPA and99m Tc- DMSA renograms for the right and left kidneys showed non-significant changes and strongpositive correlation for both the normal subjects and patients with kidney abnormalities. In the light of the results obtained from the present study, it could be suggested that 99mTc-DMSA could be successfully replace99mTc- DTPA in dynamic renograms in the case of the renal conditions that had been studied in the present work. This will be money and time consuming, and will lower the radiation dose to the patients. In addition, the same qualities of results are obtained with both radiopharmaceuticals in normal subjects and abnormal renal function patients.

HTML

 

Re-evaluation of Liquefaction Potentiality for selected pre-liquefied sites associated with 1992 Cairo Earthquake

U+1F5122016-12-17
Abdel Hafiez H E1, 3, 4, Milad Girgis1, Mostafa Toni 2, 4, Mohamed Taha1

A moderate earthquake (Ms=5.8) was occurred On October 12, 1992 at about 25 km south west of the center of Cairo city and caused a big damage to numerous poorly constructed buildings. Many seismological phenomena were noticed and studied after this earthquake; one of the important phenomenon happened is the soil liquefaction which was associated usually with the occurrence of big sand-boils that was observed in many areas near the epicenter of the earthquake. Recently different methods are used to re-evaluate the liquefaction potentiality, five different sites that showed high liquefaction potentiality during Cairo Earthquake, have been selected to re-evaluate for liquefaction potentiality depending on one the new tools. Shear wave velocity determination provide a promising approach to calculate the factor of safety (FS) against liquefaction, and resistance evaluation of sandy soils against this phenomenon. Multi-channel analysis of surface wave (MASW) method as a recent powerful tool is used to detect the velocity model beneath the studied sites to be used as input for calculation of factor of safety (FS) as an indication for liquefaction potentiality. The aim of this research is to study the potentiality of occurring of the liquefaction phenomenon in a pre-reported sites surrounding Cairo earthquake based on detailed investigation of the soil characterization. The selected five sites named Aquaz, Atf, Bedsa, El-Gammal, Zaweit Dahshour showed a high liquefaction performance during Cairo earthquake which forced us to re-evaluate and update our knowledge through the recent technique about the liquefaction potentiality at these sites. The Factor of safety obtained using shear wave was compared with the values obtained using SPT from previous study of one of the authors, the results show more improvement with reliability through this study beside the accurate calculation of the shear wave, which gave an indication that using Shear wave velocity is a promising tool for re-evaluation of the liquefaction potentiality.

HTML