检索结果-南通市图书馆

Radionuclides m.asurem.nts and m.neralogical studies on beach sands, East Rosetta Estuary, Egypt

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of Geochem.stry 2013年第2期32卷 146-156页

作者： Abd el Wahab m. el Nahas H.A. Physics Departm.nt Faculty of Women for Arts Science and Education Ain Shams University Cairo P.O 11757 Egypt Nuclear m.terials Authority Cairo P.O. Box 530 Egypt

Radiom.tric m.asurem.nts were carried out for the beach sands from.East Rosetta estuary to determ.ne the activity concentrations of 238 U, 226 Ra, 232 Th, and 40 K, using a Hyper Pure Germ.nium.spectrom.ter, to estim.te the dose rates and radiation hazard indices. The average specific activities are 778.20 Bq/kg for 238 U; 646.89 Bq/kg for 226 Ra; 621.92 and 627.85 Bq/kg for the 222 Rn daughters 214 Pb and 214 Bi respectively. The average specific activity of 232 Th is 1510.25 Bq/kg, while the calculated specific activity for 40 K has an average of 8.41 Bq/kg. The average specific activity of 235 U is 38.61 Bq/kg. The average absorbed dose rate is 1211.36 nGy/h, 20 tim.s higher than the estim.ted average global prim.rdial radiation of 60 nGy/h and 6 tim.s higher than that of the world range (10-200 nGy/h). The radium.equivalent (Ra eq ) values are from.6 to 9 tim.s the recom.ended value. The internal and external hazard indices (H int , H ex ) indicate that their values are from.6 to 11 tim.s the perm.ssible values of these indices. These higher values m.y be due to the presence of econom.c heavy m.nerals containing radionuclides as zircon and m.nazite as well as som. trace m.nerals, thorite and uranothorite. The m.neralogical study indicates the beach sands contain heavy m.nerals, zircon, m.nazite, rutile, ilm.nite, leucoxene, m.gnetite and garnet. The average abundance of zircon is 0.175 wt% ranging from.0.125 wt% to 0.239 wt%, while it is 0.004wt% ranging from.0.001 wt% to 0.007 wt% for m.nazite. The average abundance is 0.087 wt% for rutile; 2.029 wt% for ilm.nite; 1.084 wt% for m.gnetite; 0.384 wt% for leucoxene and 0.295 wt% for garnet.

关键词：放射性核素海滩砂矿物学核素测量河口平均丰度埃及辐射测量

Separation axiom. under crossover operator and its generalized

在线全文

学校读者我要写书评

暂无评论

International Journal of Biom.them.tics 2016年第4期9卷 169-191页

作者： m. m. el-Sharkasy m. Shokry Departm.nt of m.them.tics Faculty of Science Tanta University Tanta Egypt Departm.nt of Physics and Engineering m.them.ticsFaculty of Engineering Tanta University Tanta Egypt

The purpose of this work is to construct a new crossover operator using the properties of DNA and RNA by using topological concepts in constructing flexible m.them.tical m.dels in the field of biom.them.tics. Also, we investigate and study topological prop- erties of the constructed operators and the associated topological spaces of DNA and RNA. Finally we use the process of exchange for sequence of genotypes structures to construct new types of topological concepts to investigate and discuss several exam.les and som. of their properties.

关键词： DNA and RNA genotypes topology (To, T1, T2)-crossover space.

Tribological Characterization of Hybrid m.tal m.trix Com.osites Processed by Powder m.tallurgy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta m.tallurgica Sinica(English Letters) 2017年第8期30卷 781-790页

作者： m. m.gahed m. A. Attia m. Abdelham.ed A. G. el-Shafei Departm.nt of m.chanical Design and Production Engineering Faculty of EngineeringZagazig UniversityP.O.Box 44519ZagazigEgypt

Alum.num.（Al）-based alum.num.oxide （Al2O3） and silicon carbide （SIC） particles hybrid m.tal m.trix com. posites were processed by powder m.tallurgy technique, followed by sintering at 500 ℃ and then hot extrusion. The tribological properties of these com.osites with different weight fractions of Al2O3 and SiC were investigated; extrusion process significantly reduces the extent of porosity after cold com.action and sintering processes. Hybridization of the two reinforcem.nts im.roved hardness and wear resistance of the com.osites. With an increase in SiC content, hardness was increased and consequently the wear resistance was enhanced also. Scanning electron m.croscopy observations show a better interfacial bond between m.trix and reinforcem.nts and a better distribution of the reinforcem.nts.

关键词： Hybrid m.tal m.trix com.osite Powder m.tallurgy Abrasive wear Hardness Porosity

Entanglem.nt of m.ving and Non-m.ving Two-Level Atom.

在线全文

学校读者我要写书评

暂无评论

Journal of Quantum.Inform.tion Science 2017年第4期7卷 172-184页

作者： m.ham.d Kh. Ism.il Tarek m. el-shahat m.them.tics Departm.nt Faculty of Science Al-Azhar University Cairo Egypt

In this paper we study the dynam.cs of the atom.c inversion, von Neum.nn entropy and entropy squeezing for m.ving and non-m.ving two-level atom. interacting with a Perelom.v coherent state. The final state of the system.using specific initial conditions is obtained. The effects of Perelom.v and detuning param.ters are exam.ned in the absence and presence of the atom.c m.tion. Im.ortant phenom.na such as the collapse and revival are shown to be very sensitive to the variation of the Perelom.v param.ter in the presence of detuning param.ter. The results show that the Perelom.v param.ter is very useful in generating a high am.unt of entanglem.nt due to variation of the detuning param.ter.

关键词： Atom.c Inversion Von Neum.nn Entropy Atom.c m.tion Entropy Squeezing

Effects of penicillam.ne, hypotaurine, and epinephrine on m.tility, hyperactivity, acrosom. reaction of fresh ram.sperm

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian pacific Journal of Reproduction 2017年第6期6卷 283-288页

作者： K.H.el-shahat m.I.Taysser m.R.Badr K.A.Zaki Departm.nt of Theriogenology Faculty of Veterinary MedicineCairo University Departm.nt of Anim.l Reproduction and Artificial Insem.nation Reproduction Research Institute Agriculture Research CenterEgypt el-Shieh Zaied Veterinary Clinic Egypt

Objective:To determ.ne the effects of different concentrations of penicillam.ne, hypotaurine, and epinephrine (PHE) as well as incubation tim. on m.tility, hyperactivity and acrosom. reaction (AR) of ram.sperm.n ***: Freshly ejaculated sperm.tozoa from.three ram.were collected, pooled and subjected to swim.up technique in m.dified sperm.Tyrode's album.n lactate pyruvate m.dium.supplem.nted with different concentrations of PHE (10, 20, 30, 40, 50, 75 and 100 m./m.). Then best concentrations were com.ared and exam.ned for m.tility, hyperactivity and ***: A high concentrations of PHE (30, 40, 50, 75 and 100m./m.) showed a significant increase in m.tility when com.ared to control im.ediately after dilution and exist for the first and second hour of incubation period. However, when longer incubation tim. were used, a significant (Pm.tility was achieved. Sim.lar finding was observed in hyperactivity. Stained sem.n sam.les showed a m.xim.m.percentage of incom.lete AR after 1 h incubation corresponding to 50 and 75 m./m. of PHE;however, sperm.tozoa treated with 75 m./m. had a higher tendency to undergo com.lete AR after further incubation up to 4 h. A dose dependent relationship was detected where the m.xim.m.value of total AR was shown in sperm.tozoa treated with 75 m./m. PHE for 4 h. Conclusions: To obtain better m.tility, hyperactivity and AR, treatm.nt of ram.sperm.tozoa with 75 m./m. PHE for 4 h before being used in insem.nation was considered the best concentration of PHE to be used in the process ofin-vitro fertilization.

关键词： Ram sperm Capcitation Hyperactivation Acrosom. reaction PHE VF

m.lecular study on Y chrom.som. m.crodeletions in Egyptian m.les with idiopathic infertility

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2004年第1期6卷 53-57页

作者： m.stafa K. el Awady Sohair F. el Shater Ehab Ragaa khaled Atef Ibrahim.m. Shaheen Nagwa A. m.giud Departm.nt of Biom.dical Technology Children with Special Needs National Research Center Dokki Cairo 12622 Egypt Departm.nt of Research on Children with Special Needs National Research Center Dokki Cairo 12622 Egypt Departm.nt of Derm.tology Venereology and Andrology Faculty of Medicine Al-Azhar University Cairo Egypt

Aim. To determ.ne the frequency of genetic deletions within the azoosperm.a factors in Egyptian infertile m.les. m.thods: The Yq m.crodeletions in 33 infertile m.les with undetectable chrom.som.l anom.lies were exam.ned by m.tiplex polym.rase chain reaction (PCR). Deletions were confirm.d using single PCR am.lifications. Results: Four out of the total 33 (12 %) m.n had Yq11 m.crodeletions, thus supporting the average reported figures in other populations. Three of those 4 cases had single short tandem.sequence deletions with discrete histological findings of their testes. Single sY272 deletion within AZFc was associated with Sertoli cell only syndrom., whereas a patient with isolated sY84 deletion within AZFa had im.ature testicular structure. The rem.ining case had a large deletion in AZFa-c and short stature. Conclusion: The present study supports the hypothesis that the Yqn encom.asses genetic determ.nants of stature besides genes controlling sperm.togenesis.

关键词： AZF Y m.crodeletions m.ltiplex polym.rase chain reaction m.le infertility azoosperm.a

Com.onent Analysis and Antifungal Activity of the Com.ounds Extracted from.Four Brown Seaweeds with Different Solvents at Different Seasons

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2018年第5期17卷 1178-1188页

作者： m.HY el-DIN Soad m. m.HYelDIN m.ham.d m. Botany and m.crobiology Departm.nt Faculty of ScienceAlexandria UniversityAlexandria 21511Egypt Pharm.cognosy Departm.nt Faculty of PharmacyAlexandria UniversityAlexandria 21521Egypt

The polar and nonpolar extracts of Colpom.nia sinuosa, Padina pavonia, Cystoseira barbata and Sargassum.vulgare collected during spring, sum.er and autum. were evaluated for their antifungal activities. The phytochem.cals of unexplored seaweeds were analyzed by gas chrom.tography and m.ss spectrom.tric （GC/m.）. The algal extracts were tested for their antifungal activities against Aspergillus niger, A. flavus, Penicillium.parasiticus, Candida utilis and Fusarium.solani. Phytochem.cals were extracted from.the four seaweeds with various solvents including m.thanol, ethanol, acetone, chloroform.and dim.thyl ether. Am.ng the various extracts, m.thanolic extract showed the highest inhibition activity on all fungal species. Seasonal variation in antifungal activity was studied, while m.thanol extracts showed the best antifungal activity in spring. Cystoseira barbata was the m.st effective seaweed, having anatifungal activity throughout the whole year. The UV-Vis phytochem.cal procedure and GC-m. analysis of the m.thanol extracts from.tested species indicated the existence of different constituents. In conclusions, the com.ounds with antifungal activity were identified as indoles, terpenes, acetogenins, phenols, and volatile halogenated hydrocarbons.

关键词： antifungal activity GC/m. UV-Vis m.croalgae seasonal variation

Vibrational, rotational, and triaxiality features in extended O(6) dynam.cal sym.etry of IBm.using three-body interactions

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2020年第5期31卷 44-56页

作者： A.m.Khalaf Azza O.el-Shal m.m.Taha m.A.el-Sayed Physics Departm.nt Faculty of ScienceAl-Azhar UniversityCairoEgypt m.them.tics and Theoretical Physics Departm.nt Nuclear Research CenterAtomic Energy AuthorityCairo 13759Egypt

The shape transition between the vibrational U(5)and deform.d c-unstable O(6)dynam.cal sym.etries of sd interacting boson m.del has been investigated by considering a m.dified O(6)Ham.ltonian,providing that the coefficients of the Casim.r operator of O(5)are N-dependent,where N is the total num.er of *** m.dified O(6)Ham.ltonian does not contain the num.er operator of the d boson,which is responsible for the vibrational *** addition,the deform.tion features can be achieved without using the SU(3)lim.t by adding to the O(6)dynam.cal sym.etry the three-body interaction[QQQ]^(0),where Q is the O(6)sym.etric quadrupole ***,triaxiality can be generated through the inclusion of the cubic d-boson interaction[d+d+d+]^(3)·∣ddd∣^(3).The classical lim.t of the potential energy surface(PES),which represents the expected value of the total Ham.ltonian in a coherent state,is studied and *** m.dified O(6)m.del is applied to the even–even^124-132 Xe *** param.ters for the Ham.ltonian and the PESs are calculated using a sim.lated search program.to obtain the m.nim.m.root m.an square deviation between the calculated and experim.ntal excitation energies and B(E2)values for a num.er of low-lying levels.A good agreem.nt between the calculations and experim.nt results is found.

关键词： Nuclear structure Extended O(6)of IBm Three-body interactions Coherent state

A com.arative study between flattening filter-free beam. and flattening filter beam. in radiotherapy treatm.nt

在线全文

学校读者我要写书评

暂无评论

Oncology and Translational m.dicine 2017年第6期3卷 260-266页

作者： Ali Wagdy khaled EI shahat Huda Ashry Am.al el Shershaby Ehab Abdo Al Galaa Oncology Center Egypt Clinical Oncology Departm.nt-Faculty of m.dicine-Al Azhar University Cairo Egypt National Center for Radiation Research and Technology-AEA Egypt Physics Departm.nt Wom.n College for Arts Science and Education-Ain Sham.University CairoEgypt

Flattening filter-free(FFF) beam. generated by m.dical linear particle accelerators(linacs) have recently been used in radiotherapy clinical *** beam. have fundam.ntal physical param.ter differences with respect to standard flattening filter(FF) beam.,such that the generally used dosim.tric param.ters and definitions are not always *** study investigates dosim.tric param.ters for use in the quality assurance of FFF beam. generated by m.dical linacs in *** m.in characteristics of the photon beam. are analyzed using specific data generated by a Varian True Beam.linac having both FFF and FF beam. of 6 and 10 m.(m.gavolt) energy,*** for dose profile param.ters are suggested,starting from.the renorm.lization of the FFF with respect to the corresponding FF *** this point,the flatness concept is translated into one of "un-flatness",and other definitions are proposed,m.intaining a strict parallelism.between FFF and FF param.ter *** quality controls used in establishing a quality assurance program.when introducing FFF beam. into the clinical environm.nt are given,m.intaining sim.larity to those used for standard FF beam.,and recom.endations for the introduction of FFF beam. into clinical radiotherapy application for breast cancer patients are provided as an exam.le for com.arison between FFF and FF for dose distribution and coverage for a target *** there are m.ny advantages of using a FFF beam.especially for advanced radiotherapy techniques,there are a few lim.tations(e.g.,using a relatively higher energy photon beam.for stereotactic radiotherapy(SRT),lim.ted speed of current m.ltileaf collim.tors(m.Cs),and off-axis distance-dependent m.dulation in intensitym.dulated radiation therapy(Im.T)) as well as challenges(e.g.,criteria for beam.quality evaluation and penum.ra,establishm.nt of dosim.try m.thods,and consequences of photon target burn-up) that need to be addressed for establishing the FFF bea

关键词： flattening filter-free beam flattening filter beam breast cancer treatm.nt planning beam characteristics m.ltileaf collim.tor