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Diode Pumped High Peak Power Quasi Q-Switched and Passively Q-Switched Nd:YVO<sub>4</sub>Lasers at 1064 nm and 532 nm using Cr:YAG and KTP crystals

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Optics and Photonics Journal 2013年第1期3卷 51-62页

作者： ashraf f. el-sherif Mahmoud M. Talat Military Technical Institute Cairo Egypt Townes Laser Institute CREOL College of Optics and Photonics University of Central Florida Orlando USA

Diode end-pumped solid-state lasers have the potential to yield high quality laser beams with high ef.iciency f.r laser range f.nding and warning receiver applications as well as day and night military laser designation systems. In this paper we presents theoretical calculations using Advanced Dynamics Prof.ssional LASCAD sof.ware and experimental studies f.r a high power pigtailed f.ber diode laser module of.8 W operating at 808 nm with a specially designed high ef.iciency cooling system, end pumped high-ef.iciency Nd:YVO4 laser of.3 × 3 × 10 mm rod and overall cavity length of.44 mm. To the best of.our knowledge a self.Q-switching ef.ects was generated in Nd:YVO4 laser by changing the cavity dimensions and the position of.the intracavity KTP crystal at certain regime of.operation f.r the f.rst time, in which the cavity length is reduced to be 30 mm and the distance between Nd:YVO4 rod and KTP crystal is only 1mm. Self.Q-switched laser pulse at 532 nm with high peak power of.96 W, pulse width of.88 ns at f.HM and repetition rate of.400 kHz was achieved. Experimental studies of.a passive Q-switched Nd:YVO4 laser using Cr:YAG crystal with three dif.erent transmissions of.30%, 40% and 70% were investigated. Passive Q-switched laser pulse at 1064 nm and narrow line width of.less than 1.5 nm with highest peak power of.nearly 18 kW, short pulse width of.less than 4 ns at f.HM and higher repetition rate of.45 kHz using Cr:YAG with transmission of.30% was achieved f.r the f.rst time.

关键词： High Power Diode Laser High Power Nd:YVO4 Laser Cr:YAG Saturable Absorber Mirror Passive Q-Switching KTP Crystal Self Q-Switching Special Cooling System

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Hyperspectral imaging and remote trace detection of.cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)compared with traditional explosives using laser induced f.uorescence

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Def.nce Technology（防务技术） 2021年第5期17卷 1609-1616页

作者： Hany S.Ayoub ashraf f.el-sherif Ahmed elbeih Department of.Physics Faculty of ScienceCairo UniversityEgypt Laser Photonics Research Center Engineering Physics DepartmentMilitary Technical CollegeCairoEgypt Explosives Department Military Technical CollegeKobry ElkobbahCairoEgypt

cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole(BCHMX)is an advanced energetic compound that expected to spread worldwide in the near ***,no approved remote detection methods were reported in current literature f.r this material,we perf.rmed hyper-spectral imaging and laser induced f.uorescence(LIf.to a BCHMX sample under low laser f.uence f.r determining the optimum laser wavelength used in any f.ture BCHMX-LIf.based remote detection *** this purpose,an experimental setup consisted of.a sun spectrum lamp and hyper-spectral camera was built to illuminate and image white powder samples of.BCHMX in comparison with the traditional explosives,HMX(1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane),RDX(1,3,5-trinitro-1,3,5-triazacyclohexane),PETN(2,2-Bis[(nitroxy)methyl]propane-1,3-diyldinitrate).The imaging reveals strong BCHMX sample absorption contrast among other samples at wavelength ranging f.om 400 to 410 *** light source was replaced by a 405 nm laser diode illuminator,a strong BCHMX sample LIf.at the spectral range f.om 425 to 700 nm was observed under low laser f.uence condition of.0.1 mJ/cm^(2).f.nally,we demonstrated successf.lly the ability of.the 405 nm LIf.and the hyperspectral imaging technique to detect f.nger print traces of.BCHMX on white cellulose f.bric f.om a distance of.15 m and a detection limit of.1 mg/cm^(2).

关键词： Hyperspectral imaging Remote trace detection BCHMX Laser induced f.uorescence

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Ef.icient Data Compression of.ECG Signal Based on Modif.ed Discrete Cosine Transf.rm

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Computers, Materials & Continua 2022年第6期71卷 4391-4408页

作者： ashraf Mohamed Ali Hassan Mohammed S.Alzaidi sherif S.M.Ghoneim Waleed el Nahal electronics and Communications Engineering Department Faculty of EngineeringSinai UniversityArishCO 45511Egypt Department of.electrical Engineering College of EngineeringTaif UniversityTaif21944Saudi Arabia f.culty of.Technology and Education Suez UniversitySuez43527Egypt electronics and Communications Engineering Department Faculty of EngineeringMSA UniversityCO 12585Egypt

This paper introduced an ef.icient compression technique that uses the compressive sensing(CS)method to obtain and recover sparse electrocardiography(ECG)*** recovery of.the signal can be achieved by using sampling rates lower than the Nyquist f.equency.A novel analysis was proposed in this *** apply CS on ECG signal,the f.rst step is to generate a sparse signal,which can be obtained using Modif.ed Discrete Cosine Transf.rm(MDCT)on the given *** transf.rmation is a promising key f.r other transf.rmations used in this search domain and can be considered as the main contribution of.this paper.A small number of.wavelet components can describe the ECG signal as related work to obtain a sparse *** technique f.r ECGsignal compression,which is a novel area of.research,is *** signals are introduced randomly between any successive beats of.the ***-BIH database can be represented as the experimental database in this domain of.***-BIH database consists of.various ECG signals involving a patient and standard ECG *** can be considered as the simulation tool used in this *** proposed method’s uniqueness was inspired by the compression ratio(CR)and achieved by *** perf.rmance measurement of.the recovered signal was done by calculating the percentage root mean dif.erence(PRD),mean square error(MSE),and peak signal to noise ratio(PSNR)besides the calculation of.***,the simulation results indicated that this work is one of.the most important works in ECG signal compression.

关键词： Compressive sensing sparse beats of.hearts compression ratio percentage root mean dif.erence

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Monoclonal antibodies:Principles and applications of.immmunodiagnosis and immunotherapy f.r hepatitis C virus

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World Journal of.Hepatology 2015年第22期7卷 2369-2383页

作者： ashraf Tabll Aymn T Abbas sherif el-Kaf.awy Ahmed Wahid Microbial Biotechnology Department (Biomedical Technology Group) Genetic Engineering and Biotechnology DivisionNational Research Centre Biotechnology Research Laboratories Gastro--eneterology Surgery CentreMansoura University Special Inf.ctious Agents Unit King Fahd Medical Research CenterKing Abdulaziz University National Liver Institute Menoufia University Biochemistry Department Molecular and Cellular Biology UnitFaculty of PharmacyMinia University

Hepatitis C virus(HCV) is a major health problem worldwide. Early detection of.the inf.ction will help better management of.the inf.cted cases. The monoclonal antibodies(m Ab) of.mice are predominantly used f.r the immunodiagnosis of.several viral,bacterial,and parasitic antigens. Serological detection of.HCV antigens and antibodies provide simple and rapid methods of.detection but lack sensitivity specially in the window phase between the inf.ction and antibody development. Human mA b are used in the immunotherapy of.several blood malignancies,such as lymphoma and leukemia,as well as f.r autoimmune diseases. In this review article,we will discuss methods of.mouse and human monoclonal antibody production. We will demonstrate the role of.mouse mA b in the detection of.HCV antigens as rapid and sensitive immunodiagnostic assays f.r the detection of.HCV,which is a major health problem throughout the world,particularly in Egypt. We will discuss the value of.HCV-neutralizing antibodies and their roles in the immunotherapy of.HCV inf.ctions and in HCV vaccine development. We will also discuss the dif.erent mechanisms by which the virus escape the ef.ect of.neutralizing mA b. f.nally,we will discuss available and new trends to produce antibodies,such as egg yolk-based antibodies(Ig Y),production in transgenic plants,and the synthetic antibody mimics approach.

关键词： Hepatitis C virus Monoclonal antibodies Immunodiag

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Robust and High Accuracy Algorithm f.r Detection of.Pupil Images

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Computers, Materials & Continua 2022年第10期73卷 33-50页

作者： Waleed el Nahal Hatim G.Zaini Raghad H.Zaini sherif S.M.Ghoneim ashraf Mohamed Ali Hassan electronics and Communications Engineering Department Faculty of EngineeringMSA UniversityCO12585Egypt Computer Engineering Department College of Computer and Information TechnologyTaif UniversityTaif21944Saudi Arabia f.culty of.Health and Rehabilitation Sciences Princess Nourah bint Abdulrahman UniversityRiyadhSaudi Arabia Department of.electrical Engineering College of EngineeringTaif UniversityTaif21944Saudi Arabia electronics and Communications Engineering Department Faculty of EngineeringSinai UniversityArishCO45511Egypt

Recently,many researchers have tried to develop a robust,f.st,and accurate *** algorithm is f.r eye-tracking and detecting pupil position in many applications such as head-mounted eye tracking,gaze-based human-computer interaction,medical applications(such as deaf.and diabetes patients),and attention *** real-world conditions challenge the eye appearance,such as illumination,ref.ections,and *** the other hand,individual dif.erences in eye physiology and other sources of.noise,such as contact lenses or *** present work introduces a robust pupil detection algorithm with and higher accuracy than the previous attempts f.r real-time analytics *** proposed circular hough transf.rm with morphing canny edge detection f.r Pupillometery(CHMCEP)algorithm can detect even the blurred or noisy images by using dif.erent f.ltering methods in the pre-processing or start phase to remove the blur and noise and f.nally the second f.ltering process bef.re the circular Hough transf.rm f.r the center f.tting to make sure better *** perf.rmance of.the proposed CHMCEP algorithm was tested against recent pupil detection *** and results show that the proposed CHMCEP algorithm achieved detection rates of.87.11,78.54,58,and 78 according to´Swirski,ExCuSe,else,and labeled pupils in the wild(LPW)data sets,*** results show that the proposed approach perf.rms better than the other pupil detection methods by a large margin by providing exact and robust pupil positions on challenging ordinary eye pictures.

关键词： Pupil detection eye tracking pupil edge morphing techniques eye images dataset

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Chandelier-assisted scleral buckling using wide angle viewing contact lens f.r pseudophakic retinal detachment repair

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International Journal of.Ophthalmology(English edition) 2019年第4期12卷 627-633页

作者： ashraf Ahmed Nossair Wael Ahmed Ewais sherif Ahmed Eissa Department of.Ophthalmology Faculty of Medicine Cairo University Dar el Oyoun Hospital

AIM: To evaluate a modif.ed technique f.r scleral buckling(SB) in pseudophakic retinal detachment(RD).METHODS: A retrospective non-comparative study included 21 consecutive eyes with uncomplicated pseudophakic RD that was repaired by chandelier assisted SB using wide angle viewing(WAV) contact lens. Segmental tire alone was used in 5 eyes(23.81%), and combined with encircling band in 7 eyes(33.33%). Radial sponge alone was used in 3 eyes(14.29%) and combined with encircling band in 6 eyes(28.57%).RESULTS: Primary success rate was(90.48%). External drainage of.subretinal f.uid was perf.rmed in 8 eyes(38.1%). Intraoperative complications included vitreous prolapse at chandelier sclerotomy site in 4 eyes(19.05%) and localized subretinal hemorrhage at drainage site in one eye(4.76%). No case of.intraocular lens(IOL) displacement, retinal incarceration or iatrogenic retinal tear was detected. Postoperative complications included choroidal detachment in one eye(4.76%), elevated intraocular pressure in 2 eyes(9.52%), epiretinal membrane f.rmation in one eye(4.76%) and prolif.rative vitreoretinopathy in 3 eyes(14.29%). Mean postoperative corrected distance visual acuity was 0.7±0.3 logMAR units. CONCLUSION: Chandelier-assisted SB using WAV contact lens is a reliable technique f.r repairing selected cases of.simple pseudophakic RD.

关键词： buckling pseudophakia rhegmatogenous detachment

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Synthesis, spectral, optical and anti-inf.ammatory activity of.complexes derived f.om 2-aminobenzohydrazide with some rare earths

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Journal of.Rare Earths 2015年第7期33卷 758-764页

作者： Nasser Mohammed Hosny el Sayed A.el Morsy Yousery E.sherif Chemistry Department Faculty of Science Port-Said University Clinical Pharmacology Department Faculty of Medicine Mansoura University Pharmacology and Therapeutics Department Qassim College of Medicine Qassim University Department of.Chemistry Faculty of Science and Arts Taibah University

Three new metal complexes derived f.om Er（Ⅲ）, Dy（Ⅲ） and Zr（Ⅳ） with 2-aminobenzohydrazide （ABH） were synthesized and characterized by elemental analyses, IR, ^1H-NMR, ES-MS and transmission electron microscopy （TEM）. The morphology and the particle size were determined by TEM. The results showed that the ligand acted as neutral bi-dentate coordinating to the metal ions through the carbonyl oxygen and amidic amino nitrogen. The aromatic amine group remained inert towards coordination. The optical band gap was measured and f.und to be 3.3, 3.5 and 4.3 eV f.r Er（Ⅲ）, Dy（Ⅲ） and Zr（Ⅳ）, respectively. The optical band gap values indicated a semi-conducting nature of.the investigated complexes. The anti-inf.ammatory and analgesic activities of.the tested compounds were determined and compared with standard meloxicam.

关键词： Er(Ⅲ) Dy(Ⅲ) Zr(Ⅳ) metal complexes optical band gap rare earths

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Thermochemical Aspects of.Activated Ammonium Perchlorates with Superior Thermal Stability,Decomposition Enthalpy,Propagation Index,and Decomposition Kinetic Parameters

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Journal of.Thermal Science 2021年第6期30卷 2196-2201页

作者： sherif elbasuney M.Yehia SHUKRI Ismael sherif f.rag AHMED Saleh GHARIEB S.el-Sayyad Head of.Nanotechnology Research Center Military Technical College(MTC)Cairo 11646Egypt School of.Chemical Engineering Military Technical College(MTC)Cairo 11646Egypt Science and Technology Center of.Excellence Cairo 11646Egypt Drug Radiation Research Department National Center for Radiation Research and Technology(NCRRT)Egyptian Atomic Energy Authority(EAEA)Cairo 11646Egypt

Ammonium perchlorate(AP)includes oxidizing and reducing elements on the same *** can act as an ef.icient oxidizer and mono-propellant as *** this study,AP experienced crystallographic phase change f.om orthorhombic centrosymmetric to non-centrosymmetric under controlled isothermal heat *** dif.ractograms conf.rmed this crystallographic phase *** thermal behaviour of.activated AP had been investigated using *** AP demonstrated high chemical stability with an increase in endothermic phase transition enthalpy by 170%.The enthalpy of.the subsequent two main exothermic decomposition reactions was increased by 250%.Whereas AP demonstrated total decomposition enthalpy of.733 J/g,activated AP showed 2614 J/*** AP can secure self.sustained response at a high *** index(combustion enthalpy/ignition temperature)was employed to assess self.sustained reaction *** AP demonstrated high propagation index of.8.7 compared with 2.5 f.r un-activated *** decomposition kinetic parameters had investigated using Kissinger and KAS *** AP showed an increase in activation energy by 89%using the Kissinger method;kinetic parameters using the KAS method were in good agreement with the Kissinger *** can have concluded that AP with novel kinetic decomposition parameters f.r enhanced saf.ty storage and high combustion characteristics has evolved.

关键词： solid propellants oxidizers thermal behavior Kinetic parameters activation energy

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Removal of.trace arsenic(V) and phosphate f.om water by a highly selective ligand exchange adsorbent

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Journal of.Environmental Sciences 2011年第12期23卷 1947-1954页

作者： Md. Rabiul Awual sherif A. el-Saf.y Akinori Jyo National Institute f.r Materials Science Exploratory Materials Research Laboratory for Energy and Environment 1-2-1 Sengen TsukubaIbaraki 305-0047 Japan Department of.Applied Chemistry and Biochemistry Kumamoto University Kurokami 2-39-1 Kumamoto 860-8555 Japan

A highly selective ligand exchange type adsorbent was developed f.r the removal of.trace arsenic（V）（As（V）） and phosphate f.om water. This adsorbent was prepared by loading zirconium（IV） on monophosphonic acid resin. This adsorbent was able to remove toxic anions ef.iciently at wide pH ranges. However, low pH was pref.rable f.r maximum breakthrough capacity in an adsorption operation. The ef.iect of.a large amount of.competing anions such as chloride, bicarbonate, and sulf.te on the adsorption systems of.As（V） and phosphate anions was investigated. The experimental f.ndings revealed that the As（V） and phosphate uptakes were not af.iected by these competing anions despite the enhancement of.the breakthrough points and total adsorption. Phosphate anion was slightly pref.rable than As（V） in their competitive adsorption by the adsorbent. The adsorbed As（V） and phosphate on the Zr（IV）-loaded resin were quantitatively eluted with 0.1 mol/L sodium hydroxide solution, and the adsorbent was regenerated by 0.5 mol/L sulf.ric acid. During several cycles of.adsorption-elution-regeneration operations, no Zr（IV） was detected in the column ef.uents. Theref.re, the Zr（IV）- loaded monophosphonic acid resin is an ef.ective ligand exchange adsorbent f.r removing trace concentrations of.As（V） and phosphate f.om water.

关键词： arsenic(V) phosphate ligand exchange adsorbent common anions regeneration

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Glycated Hemoglobin HbA1c:Permittivity Experimental Applications with Some Mathematical Concepts,Temperature and f.equency Variations

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Journal of.Renewable Materials 2022年第9期10卷 2335-2354页

作者： Soliman Abdalla sherif Kandil Waleed el-Shirbeeny f.tma Bahabri Department of.Physics Faculty of ScienceKing Abdulaziz UniversityJeddahSaudi Arabia Department of.Materials Science Institute of Graduate Studies and ResearchAlexandria UniversityAlexandriaEgypt Department of.Physics Faculty of ScienceJeddah UniversityJeddahSaudi Arabia

Diabetes disorder turns smoothly to be a global epidemic disorder and the glycated hemoglobin(HbA1c)starts to be an ef.icient marker of.*** dielectric spectroscopy on dif.erent human normal-and diabetic-blood samples is used to characterize and to estimate the HbA1c concentration.“dc-”and ac-measurement of.the complex conductivity in the temperature range f.om 280 K up to 320 K,and in the f.equency range f.om one Hz up to 32 MHz have been *** thermal activation energy,ΔEσ,of.dc-electric conductivity lies in the range 95 meVf.RBCs relaxation time is aboutΔEτ=140 *** experimental data have been modeled by a physical-model and good f.ttings have been f.und between calculated and experimental *** ef.ective number of.charges,nG,T,is estimated af.er Cole and Cole *** has f.und that nG,T increases with both temperature,T,and with the glycation rate *** increase may shed some light on an ef.ective and possible way to treat(and to detect)diabetes disorders via eliminating the excess electric charges produced by glycation *** present work sheds the light on the possible combination of.f.cused ultrasound with magnetic resonance imaging to study the dielectric-thermal variations of.glycated-RBCs,which can lead to very precise and non-invasive monitoring of.glycation concentration in vivo and in vitro via magnetic resonance-thermometry.

关键词： Glycated-hemoglobin rate thermal characterization red blood cells RBCs relaxation of.RBCs dielectric constant mathematical model

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