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Effect of Conductive Fillers on the Cyclic Stress-Strain and Nano-Scale Free Volume Properties of Silicone Rubber

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Chinese Journal of Polymer Science 2014年第5期32卷 558-567页

作者： m.h.abd-El Salam S.El-Gamal m.mohsen D.m.abd El-maqsoud Physics Department Faculty of Education Ain Shams University Physics Department Faculty of Science Ain Shams University

The effect of carbon black （CB） and graphite （G） powders on the macroscopic and nano-scale free volume properties of silicone rubber based on poly（di-methylsiloxane）（PDmS） was studied through thermal and cyclic mechanical measurements, as well as with positron annihilation lifetime spectroscopy （PALS）. The melting temperature of the composites （Tm） and the endothermic enthalpy of melting （Δhm） were estimated by differential scanning calorimetry （DSC）. Tm and the degree of crystallinity （χc） of PDmS composites were found to decrease with increasing the CB content. This can be explained due to the increase in physical cross-linking which results in a decrease in the crystallite thickness. Besides, χc was found to be dependent on the filler type. Cyclic stress-strain behavior of PDmS loaded with different contents of filler has been studied. mullins ratio （Rm） was found to be dependent on the filler type and content. It was found that, Rm increases with increasing the filler content due to the increase in physical cross-linking which results in a decrease in the size of free volume, as observed through a decrease of the o-Ps lifetime τ3 measured by PALS. moreover, the hysteresis in PDmS-CB composites was more pronounced than in PDmS-G composites. Furthermore, a correlation was established between the free volume Vf and the mechanical properties of PDmS composites containing different fillers. A negative correlation was observed between Vf and Rm.

关键词： Positron annihilation Positronium Free volume Si-rubber Composite Cyclic mechanical properties.

桃仁油和蛋白质的化学特性——桃仁粉的体外消化率和氨基酸分布

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中国油脂 1989年第1期14卷 32-37页

作者： E.h.Rahma m.h.abd El-Aal 马仲登

桃仁中油和蛋白质的含量分别为54.5％和27.5％,灰分和碳水化合物含量很低。总脂类中含有98％甘油三酸酯;甾醇和极性脂类分别为0.41％和1.1％。脂肪酸组成主要为油酸(63.8％)、亚油酸(15.4％);饱和脂肪酸为20.7％。脱脂粉呈现良好的吸... 详细信息

桃仁中油和蛋白质的含量分别为54.5％和27.5％,灰分和碳水化合物含量很低。总脂类中含有98％甘油三酸酯;甾醇和极性脂类分别为0.41％和1.1％。脂肪酸组成主要为油酸(63.8％)、亚油酸(15.4％);饱和脂肪酸为20.7％。脱脂粉呈现良好的吸油和乳化特性, 但是吸水作用和发泡能力较低。在酸性和碱性两种ph下蛋白质的溶解度都高;在ph4.3情况下,溶解度最低。清蛋白是蛋白质的主要组成成份(占60％);其次为非蛋白质氮(17％)、球蛋白和谷蛋白组分为9.5％和8.2％、醇溶谷蛋白仅为6.0％。胃—胰蛋白酶对蛋白质消化力最高, 而胰蛋白酶消化率最低。蛋白质富含赖氨酸、亮氨酸、异亮氨酸、缬氨酸、苏氨酸、以及碱性和酸性氨基酸,但是蛋氨酸缺乏。聚丙烯酰胺凝胶电泳分析(PAGE)表明,由不同迁移率分离出五条谱带,它们含有高和低的两种分子量的蛋白质。

关键词：食品化学桃仁桃仁成份桃仁粉

Dysprosium oxide,alumina,and graphene oxide reinforced polycaprolactone thin films:Thermal stability,morphology,and cell viability

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Journal of Rare Earths 2024年第7期42卷 1337-1343,I0005页

作者： mohamed Tharwat Elabbasy mohamed R.Atteya mai A.Samak mousa abdelrahman Tahani Almahmoud m.A.El-morsy A.A.menazea m.F.h.abd El-Kader Department of Public health College of Public Health and Health InformaticsUniversity of Ha'ilHa'il2440Saudi Arabia Food Control Department Faculty of Veterinary MedicineZagazig UniversityZagazig44519Egypt Department of Physical Therapy College of Applied Medical SciencesUniversity of Ha'ilHa'ilSaudi Arabia Department of histology and Cell Biology Faculty of MedicineZagazig UniversityZagazig44519Egypt College of Nursing University of Ha'ilHa'ilSaudi Arabia College of Science and humanities in Al-Kharj Physics DepartmentPlasma Technology and Material Science UnitPrince Sattam Bin Abdulaziz UniversityAl-kharj11942Saudi Arabia Physics Department Faculty of ScienceUniversity of DamiettaNew Damietta34517Egypt Spectroscopy Department Physics Research InstituteNational Research CentreDokki12622GizaEgypt Biophysics Department Faculty of ScienceCairo UniversityGizaEgypt

Developing a biomaterial for wound healing applications is still a ***,dysprosium oxide(Dy_(2)O_(3)),aluminum oxide(Al_(2)O_(3)),and graphene oxide(GO)were embedded in cast films based on polycaprolactone(PCL)to be examined for wound dressing *** techniques were used to characterize the fabricated films including X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),Raman,and scanning electron microscopy(SEm),besides their biological *** thermogravimetric analysis(TGA)exhibits high thermal stability as the scaffold weight decreases slightly to 98.6%after raising the temperature from room temperature to 280℃.The cell viability was investigated and it is shown that the viable cells grow up to approximately 93%at 75μg/***,the cell attachment shows excellent behavior as the cells attach on most of the surface of the modified PCL which shows high biocompatibility.

关键词： Wound healing Polycaprolactone Dy_(2)O_(3) Al_(2)O_(3) Biocompatible Rare earths

Langmuir-Schaefer Film Investigation and Density Functional Theory Band Gap Calculations of Calix[n]arene-Para-Aminobenzoic Acid for Drug Nanosensor Application

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Journal of Wuhan University of Technology(materials Science) 2024年第5期39卷 1311-1318页

作者： WONG Yeong Yi F L Supian A Radzwan m musa N F N abd Karim Department of Physics Sultan Idris Education UniversityTanjong Malim 35900Malaysia Department of Chemistry Sultan Idris Education UniversityTanjong Malim 35900Malaysia

Calix[n]arenes was utilized to detect PABA,the primary sunscreen *** study investigates the interaction of calix[4]arene(C4),calix[6]arene(C6),and PABA using the Langmuir method and first-principle density functional theory(DFT).Using the Langmuir-Schaefer(LS)technique,an ultrathin film composed of calix[n]arenes and their complexes with PABA was deposited on various *** on the Langmuir study,the PABA molecule was bonded to the lower rims of both C4 and C6 with the host-guest ratio of 1:*** of the LS films formed were then characterized by ultravioletvisible spectroscopy(UV-Vis),Fourier-transform infrared spectroscopy(FTIR)and carbon,hydrogen,nitrogen,sulfur elemental analyzer(ChNS).The band gap reduction obtained in the DFT study denotes the charge transfer interaction with promising reactivity between the calix[n]arenes and *** sensing of PABA by C4 and C6 is successful based on the formation of bonding between them due to the hosts’effective trapping *** outcomes of this study could be applied to drug delivery systems for future pharmaceutical and medical applications.

关键词： calix[n]arenes band gap density functional theory Langmuir-Schaefer PABA sensor

Optimization of Cooperative Relayingmolecular Communications for Nanomedical Applications

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Computer modeling in Engineering & Sciences 2024年第2期138卷 1259-1275页

作者： Eman S.Attia Ashraf A.m.Khalaf Fathi E.abd El-Samie Saied m.abd El-atty Konstantinos A.Lizos Osama Alfarraj heba m.El-hoseny Department of Electrical Engineering Faculty of EngineeringMinia UniversityMinia61111Egypt Department of Electronics and Electrical Communications Engineering Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt Department of Informatics Faculty of Mathematics and Natural SciencesUniversity of Oslo(UiO)OsloNorway Computer Science Department Community CollegeKing Saud UniversityRiyadh11437Saudi Arabia Department of Computer science The Higher Future Institute for Specialized Technological StudiesEl ShoroukEgypt

Recently,nano-systems based on molecular communications via diffusion(mCvD)have been implemented in a variety of nanomedical applications,most notably in targeted drug delivery system(TDDS)***,because the mCvD is unreliable and there exists molecular noise and inter symbol interference(ISI),cooperative nano-relays can acquire the reliability for drug delivery to targeted diseased cells,especially if the separation distance between the nano transmitter and nano receiver is *** this work,we propose an approach for optimizing the performance of the nano system using cooperative molecular communications with a nano relay scheme,while accounting for blood flow effects in terms of drift *** fractions of the molecular drug that should be allocated to the nano transmitter and nano relay positioning are computed using a collaborative optimization problem solved by themodified Central Force Optimization(mCFO)*** the previous work,the probability of bit error is expressed in a closed-form *** is used as an objective function to determine the optimal velocity of the drug molecules and the detection threshold at the nano *** simulation results show that the probability of bit error can be dramatically reduced by optimizing the drift velocity,detection threshold,location of the nano-relay in the proposed nano system,and molecular drug budget.

关键词： Nanomedical system molecular communication cooperative relay optimization

Assessment of groundwater suitability for different activities in Toshka district,south Egypt

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Journal of Groundwater Science and Engineering 2024年第1期12卷 34-48页

作者： marwa m Aly Shymaa AK Fayad Ahmed mI abd Elhamid Faculty of Engineering mataria Helwan UniversityCairo 11718Egypt Division of Engineering International Academy for Engineering and Media Science(IAEMS)6th of October City 15515Egypt hydraulics Research Institute National Water Research CenterMWRICairo 13621Egypt

Globally,groundwater has globally emerged as a crucial freshwater source for domestic,irrigation,and industrial *** evaluation of groundwater quality in the Toshka region is imperative to ensure its suitability for the extensive agricultural and industrial activities underway in this promising,groundwater-dependent development *** is particularly significant as Egypt increasingly relies on groundwater reserves to address freshwater deficits and to implement mega-development projects in barren *** this study,fifty-two samples were collected from the recently drilled wells tapping into the Nubian Sandstone Aquifer(NSA)in the Toshka *** quality was assessed through hydrochemical analysis,Piper diagram,and various indicators such as Na%,SAR,RSC,KR,mh and *** hydrochemical analysis revealed improved groundwater quality characteristics,attributed to continuous recharge from Lake *** Piper diagram categorised most of the water samples as"secondary salinity"water *** all wells proved suitable for irrigation with only two wells unsuitable based on mh values and six wells based on KR *** Total hardness(Th)values,all samples were classified as"Soft",indicating their suitability for domestic and industrial *** Quality Index(WQI)results concluded that all samples met WhO and FAO guidelines for drinking and irrigation,*** distribution maps,constructed using GIS,facilitate the interpretation of the *** monitoring of quality parameters is essential to detect any deviation from permissible limits.

关键词： Nubian Sandstone Aquifer Water Quality Assessment hydro-chemical Analysis Irrigation Quality Indicators Domestic Use Water Quality Index

Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 543-562页

作者： h.m.FEIZABAD m.h.YAS Department of mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQm)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQm)

Depositional environment， petrophysical evaluation and electrical properties of Zeit Formation， Northwestern shore of Gulf of Suez， Egypt

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Journal of Earth Science 2024年

作者： mohamed m.Gomaa Emad A.abd El Aziz Geophysical Sciences Department， National Research Centre El-Behoos St.， Dokki， Cairo， Egypt.

The Zeit sand reservoir is one of the most prolific formations at Northwestern side of the Gulf of Suez. In this research we will try to coordinate between electrical， petrophysical properties， depositional environment and facies discrimination in order to evaluate the hydrocarbon potentiality of studied Zeit formation. The statistical parameters for potassium (K)， thorium (Th) and Th/U ratio contents have a general increase towards northwestern parts， whereas uranium (U) content has a general increase towards southeastern parts. The sandstone facies is distinguished from the other facies by its thorium content >4 ppm. U has high carbonate content (U ≥1 ppm). Rocks’ electrical properties vary greatly depending on a number of factors. Electrical measurements were taken at frequencies range of (5×10-4hz–100 khz) for fully saturated samples (clayey sandstone) with NaCl (20 gm/Littre). As salinity， clay content， and frequency increase， consequently does the electrical properties. The continental condition are present in northwestern part (back-sea) which is distinguished by high K percent， high Th， high Th/U ratio， and low U contents. Low K， Th， and Th/U ratio contents， with high U contents， characterize the marine depositional environment that existed around the east and southeastern parts (fore-sea coincide with the dipping of strata). Furthermore， the studied Zeit Formation has good petrophysical properties that coincide with marine conditions. The middle and eastern parts (around ISS-94 and CSS-288) is a good reservoir (porosity 36%–39%， shale content hydrocarbon saturation 71%–92%， and net pay thickness 17–63 feet).

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Crystal structure and luminescence dynamics of highly pure Lim(PO_(3))_(3):Eu^(3+)(m=Sr,Ca) red phosphors for white light emitting diodes

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Journal of Rare Earths 2024年第8期42卷 1470-1478,I0002页

作者： Payal Khajuria m.manhas A.K.Bedyal Ankush Vij h.C.Swart Vinay Kumar Department of Physics and Astronomical Sciences Central University of JammuRahy-Suchani.Samba1143J&KIndia Department of Physics School of SciencesCluster University of JammuCanal RoadJammu180001India Department of Physics University of Petroleum and Energy StudiesDehradunUttarakhand248007India Department of Physics University of the Free StateP.O.Box 339BloemfonteinZA 9300South Africa

highly pure red phosphors Lim(PO_(3))_(3):Eu^(3+)(m=Sr,Ca) doped with Eu^(3+)(1 mol%) were synthesized via solution combustion method and their crystal structure and luminescence dynamics were studied to explore its suitability in white light emitting *** Rietveld refinement analysis of the powder Xray diffraction patterns reveals that the phosphors belong to the pure triclinic phase of LiSr(PO_(3))_(3) and LiCa(PO_(3)) with space group P-1(2).The scanning electron microscopy images showed the agglomerated *** photoluminescence emission spectra under 393 nm show an orange band at 594 nm and a red band at 613 nm ascribed to ^(5)D_(0)→^(7)F_(1).^(5)D_(0)→^(7)F_(2) transitions of Eu^(3+)ion in both the ***,the spectroscopic properties such as luminescence behaviour,and Stark splitting were used to examine the symmetry of Eu^(3+)ions in Lim(PO_(3))_(3):Es^(3+)(m=Sr,Ca) phosphors in terms of distortion induced upon *** Stark splitting shows that the actual site symmetry for Eu^(3+)ion was estimated to be D_(2) type for both *** photometric properties of LiCa(PO_(3))_(3):Eu^(3+)such as Commission International de l'Eclairage coordinates(x=0.64,y=0.36) near to the standard one(red),high color purity(95%) and higher brightness reveal that the phosphor has the capability of acting as a red component in n-UV white light emitting diodes.

关键词： Photoluminescence Phosphate WLEDs Stark splitting Rare earths