In the present study,the effect of aging heat treatment at 650,750,and 850？C on the impact toughness of 316L austenitic stainless steel,2205 duplex stainless steel and their weldments has been investigated.Welding pr...In the present study,the effect of aging heat treatment at 650,750,and 850？C on the impact toughness of 316L austenitic stainless steel,2205 duplex stainless steel and their weldments has been investigated.Welding process was conducted using the TIG（tungsten inert gas） welding technique.Instrumented impact testing,at room temperature,was employed to determine the effect of aging treatment on the impact properties of investigated materials.Aging treatment resulted in degradation in the impact toughness as demonstrated by the reduction in the impact fracture energy and deformation parameters（strain hardening capacity,fracture deffection,and crack initiation and propagation energy）.The degree of embrittlement was more noticeable in duplex stainless steel parent and weld-metal than in 316L stainless steel and became greater with the increase of aging temperature.The degradation in impact toughness was discussed in relation to the observed precipitation of the intermetallic sigma phase in the microstructure of the stainless steel weldments and the corresponding fracture surface morphology.展开更多
Cobalt is used in the manufacture of alloys, catalysts in the petroleum industry, catalytic converters, and paint pigments. Thus the potential for Co releases into the environment is highly increased. Use of waste slu...Cobalt is used in the manufacture of alloys, catalysts in the petroleum industry, catalytic converters, and paint pigments. Thus the potential for Co releases into the environment is highly increased. Use of waste sludges and sewage effluent to fertilize and irrigate soils has also increased soil Co concentrations. Total cobalt contents of alluvial delta soil of Egypt show considerable variation ranging from 13.1 to 64.7 ppm. The impact of either wastewater irrigation or industrial activities on soil total Co was obvious due to accumulation of organic matter and solid waste in the surface soil samples. Food crops and vegetables should not be grown on soil highly contaminated by Co. It is noteworthy that the delayed neutron activation analysis(DNAA) technique could be used successfully for total Co determination due to its high sensitivity. It is quit clearly that dust samples of Cairo City contains higher Co level, as compared to Suez Canal Region(Ismailia, Port Said and El-Suez cities). The high values in Cairo City may be due to the existence of industries around the city and the intensive traffic. To minimize Co environmental hazards, waste effluents should be treated on site. Thus, levels of potentially toxic Co needs to be continuously monitored and should be removed during several treatment processes before the disposal of these wastes.展开更多
Extraction of V（V） and Cr（III） from acidic sulfate leach liquors of ilmenite using 0.4 mol/L Aliquat 336 chloride in kerosene was carried out. Different parameters affecting the extraction process such as equilibr...Extraction of V（V） and Cr（III） from acidic sulfate leach liquors of ilmenite using 0.4 mol/L Aliquat 336 chloride in kerosene was carried out. Different parameters affecting the extraction process such as equilibrium time, sulfate concentration, Aliquat 336 concentration, equilibrium p H and the extraction temperature were investigated. Extraction of V（V） and Cr（III） by Aliquat 336 involved anion exchange mechanism, and the extracted species are [（VO2SO4）R4N]org at low equilibrium p H for V（V） and [R4N-Cr（OH）4]org at high equilibrium p H for Cr（III）. Calculated thermodynamic parameters show that the extraction process is endothermic reaction for V（V） and exothermic for Cr（III）. Also, calculated values of ？Gex and ？Sex indicate that the extraction reactions of V（V） and Cr（III） proceed as non-spontaneous reaction is more random. V（V） and Cr（III） were stripped, precipitated, separated and calcined at 500 °C for 2.0 h to produce the corresponding oxide in pure form after rinsing and drying.展开更多
This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol...This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol-gel method.The samples were characterized using the X-ray diffraction technique(XRD),Fourier transform infrared(FT-IR)spectroscopy,the energy dispersive X-ray spectra(EDX),inductively coupled plasma optical emission spectroscopy(ICP-OES),high resolution scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)surface area analysis,ultraviolet-diffuse reflectance spectroscopy(UV-DRS),and vibrating sample magnetometer(VSM)technique.The Rietveld refinements of the samples indicate that at higher concentrations of La^3+,nanostructures with dual phase,i.e.cubic spinel and orthorhombic LaFeO3 perovskite with space group(Pbnm)appear.Optical studies show that the energy band gap(Eg)of the bare LiCo0.25Zn0.25Fe2 O4 ferrite sample(2.18 eV)reaches up to 2.47 eV at x=0.06 and above this concentration,it drops sharply to 2.00 eV.Although the saturation magnetization and the coercivity of LiCo0.25Zn0.25LaxFe2-xO4 are lower than that of LiCo0.25Zn0.25Fe2 O4 NPs.Overall,the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo0.25Zn0.25LaxFe2-xO4 NPs are suitable to be applied in transformers core.展开更多
Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room tempe...Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room temperature.Potentiodynamic results showed that 6% Mo alloy possessed a remarkable resistance to crevice corrosion compared with 316L alloy when they are tested in the same solution. The breakdown potential at which passivity broke down for 316L alloy was 0.00 mV （SCE）. The corresponding value for 6% Mo alloy could not reach up to the potential value of 700 mV （SCE）. 316L alloy suffered extremely from crevice corrosion at room temperature （about 25℃）, which indicates that the critical crevice corrosion temperature, below which crevice corrosion does not occur, was lower than the test temperature. For 6% Mo alloy, the critical crevice corrosion temperature was higher than the testing temperature. Electrochemical parameters indicated that 6% Mo alloy exhibited higher crevice corrosion resistance than 316L alloy.展开更多
The solvent extraction of Pr(Ⅲ) and Sm(Ⅲ) with trialkyl phosphine oxide(Cyanex 923) in chloroform,carbon tetrachloride,n-octane,cyclohexane,1,2-dichloroethane,benzene,toluene,xylene and nitrobenzene from acidic nitr...The solvent extraction of Pr(Ⅲ) and Sm(Ⅲ) with trialkyl phosphine oxide(Cyanex 923) in chloroform,carbon tetrachloride,n-octane,cyclohexane,1,2-dichloroethane,benzene,toluene,xylene and nitrobenzene from acidic nitrate medium was investigated.On the basis of slope analysis data,the composition of the extracted species was determined as(M(NO3)3?2CY923),CY923 refers to Cyanex 923.The values of the equilibrium constants and the separation factors were calculated.The effect of the diluents on the metal extracti...展开更多
Objective:To assess the hepatoprotective effects of flavone on nicotine-induced liver damage.Methods:Thirty-six rats were allocated into six groups:the control group,the nicotine group,the flavone alone groups(10 and ...Objective:To assess the hepatoprotective effects of flavone on nicotine-induced liver damage.Methods:Thirty-six rats were allocated into six groups:the control group,the nicotine group,the flavone alone groups(10 and 25 mg/kg/body weight),and the nicotine groups treated with flavone(10 and 25 mg/kg/body weight).Liver function,oxidative stress,Nrf2 pathway(HO-1,Nrf2,and Keap-1),and inflammatory markers(IL-17,TNF-α,and NF-κB)were evaluated.Additionally,a histopathological examination of liver tissues was performed.Results:Nicotine increased liver damage,inflammation,and oxidative stress.However,flavone suppressed nicotine-induced liver enzymes,oxidative stress,and inflammation,as manifested by increased antioxidants and decreased malondialdehyde level,liver enzymatic activities,and inflammatory markers.Flavone(10 and 25 mg/kg/body weight)also reduced the level of Keap-1 and increased HO-1 and Nrf2 levels in the liver of nicotine-exposed rats.Conclusions:Flavone has hepatoprotective properties and may slow the progression of liver injury by reducing oxidative stress,liver enzymes,and inflammation possibly via the Nrf2 pathway.展开更多
BACKGROUND Hepatitis C virus(HCV),hepatitis B virus(HBV),and human immunodeficiency virus 1(HIV-1)are the most epidemic blood-borne viruses,posing threats to human health and causing economic losses to nations for com...BACKGROUND Hepatitis C virus(HCV),hepatitis B virus(HBV),and human immunodeficiency virus 1(HIV-1)are the most epidemic blood-borne viruses,posing threats to human health and causing economic losses to nations for combating the infection transmission.The diagnostic methodologies that depend on the detection of viral nucleic acids are much more expensive,but they are more accurate than sero-logical testing.AIM To develop a rapid,cost-effective,and accurate diagnostic multiplex polymerase chain reaction(PCR)assay for simultaneous detection of HCV,HBV,and HIV-1.METHODS The design of the proposed PCR assay targets the amplification of a short conserved region featured with a distinguishable melting profile and electro-phoretic molecular weight inside each viral genome.Therefore,this diagnostic method will be appropriate for application in both conventional(combined with electrophoresis)and real-time PCR facilities.Confirmatory in silico investigations were conducted to prove the capability of the approached PCR assay to detect variants of each virus.Then,Egyptian isolates of each virus were subjected to the wet lab examination using the given diagnostic assay.RESULTS The in silico investigations confirmed that the PCR primers can match many viral variants in a multiplex PCR assay.The wet lab experiment proved the efficiency of the assay in distinguishing each viral type through high-resolution melting analysis.Compared to related published assays,the proposed assay in the current study is more sensitive and competitive with many expensive PCR assays.CONCLUSION This study provides a simple,cost-effective,and sensitive diagnostic PCR assay facilitating the detection of the most epidemic blood-borne viruses;this makes the proposed assay promising to be substitutive for the mistakable and cheap serological-based assays.展开更多
Metal-substituted cobalt ferrites [MxCo(1-x)Fe2O4(M=Zn,Cu,Mn;x=0.0,0.25,0.5,and 0.75)]were synthesized via a sol-gel technique.The ferrite structures were confirmed by X-ray diffraction, Fourier transform infrared spe...Metal-substituted cobalt ferrites [MxCo(1-x)Fe2O4(M=Zn,Cu,Mn;x=0.0,0.25,0.5,and 0.75)]were synthesized via a sol-gel technique.The ferrite structures were confirmed by X-ray diffraction, Fourier transform infrared spectroscopy,scanning electron microscopy,surface analysis using the Brunauer-Emmett-Teller method,and energy-dispersive X-ray spectroscopy.Antimicrobial activity of these ferrites against selected pathogenic microbes was determined.The structures remained cubic spinel phases after substitution of metals.Substitution strongly influenced the microstructure and homoge- neous grain distribution.The particle size of the ferrites increased linearly with increase in their annealing temperature.The surface area of zinc cobalt ferrite nanoparticles (ZCFO)was 52.56m^2/g,the average pore size was 1.84nm,and pore volume was 0.136mL/g.All ferrites showed antimicrobial activity toward all pathogens selected.Of these,the most powerful was ZCFO,showing zones of inhibition of 13.0mm against Bacillus subtilis and Staphylococcus aureus and 12.0mm against Candida albicans.Gamma-irradiated ZCFO nanoparticles (150.0kGy)maintained higher antimicrobial activity than non-irradiated particles,e.g. being active toward S.aureus (16.0mm).ZCFO is proposed as a candidate material for industrial and biomedical purposes.展开更多
A procedure for radioiodination of valsartan with iodine-125 is carried out via an electrophilic substitution of hydrogen atom with the iodonium cation I+. All reaction parameters were studied to optimize the labeling...A procedure for radioiodination of valsartan with iodine-125 is carried out via an electrophilic substitution of hydrogen atom with the iodonium cation I+. All reaction parameters were studied to optimize the labeling conditions of valsartan and to obtain a maximum radiochemical yield (RCY) of the 125I-Valsartan [125I-Val]. By using 3.7 MBq of Na125I, 50 μg of valsartan (0.2 mM) as substrate, 25 μg of Iodogen (0.15 mM) as oxidizing agent in ethanol at room temperature for 30 min, the radiochemical yield of 125I-Val was 98.6% The radiochemical yield was determined by electrophoresis using cellulose acetate moistened with 0.02 M phosphate buffer pH 7. The labeled compound was separated and purified by means of high-pressure liquid chromatography (HPLC). The biological distribution in normal mice indicates the suitability of radioiodinated valsartan to image any cardiovascular disorders.展开更多
Spike architecture influences both grain weight and grain number per spike,which are the two major components of grain yield in bread wheat(Triticum aestivum L.).However,the complex wheat genome and the influence of var...Spike architecture influences both grain weight and grain number per spike,which are the two major components of grain yield in bread wheat(Triticum aestivum L.).However,the complex wheat genome and the influence of various environmental factors pose challenges in mapping the causal genes that affect spike traits.Here,we systematically identified genes involved in spike trait formation by integrating information on genomic variation and gene regulatory networks controlling young spike development in wheat.We identified 170 loci that are responsible for variations in spike length,spikelet number per spike,and grain number per spike through genome-wide association study and meta-QTL analyses.We constructed gene regulatory networks for young inflorescences at the double ridge stage and thefloret primordium stage,in which the spikelet meristem and thefloret meristem are predominant,respec-tively,by integrating transcriptome,histone modification,chromatin accessibility,eQTL,and protein–pro-tein interactome data.From these networks,we identified 169 hub genes located in 76 of the 170 QTL regions whose polymorphisms are significantly associated with variation in spike traits.The functions of TaZF-B1,VRT-B2,and TaSPL15-A/D in establishment of wheat spike architecture were verified.This study provides valuable molecular resources for understanding spike traits and demonstrates that combining genetic analysis and developmental regulatory networks is a robust approach for dissection of complex traits.展开更多
Bulked-segregant analysis is a time-and cost-saving strategy for identifying major quantitative trait loci(QTL) in a mapping population. Bulked-segregant analysis combined with whole-genome sequencing(BSA-seq) was per...Bulked-segregant analysis is a time-and cost-saving strategy for identifying major quantitative trait loci(QTL) in a mapping population. Bulked-segregant analysis combined with whole-genome sequencing(BSA-seq) was performed to rapidly identify QTL for heading date, plant height, and panicle length in a large F_(2) population derived from two landraces: Chuan 7(C7) and Haoboka(HBK). Twenty plants with extremely low or high phenotypic values for the target traits were selected from an F_(2) population of 940 plants to construct low-and high-value bulks. Three pairs of bulks for the three traits were constructed, resulting in six DNA pools. BSA-seq revealed nine QTL: four for heading date, three for plant height, and two for panicle length. These QTL were validated in a random F_(2) population or BC_(4)F_(2) populations. The major novel plant height QTL, qPH8, acting additively with an effect equivalent to that of semi-dwarf 1(sd1), is potentially valuable for hybrid rice breeding. qPH8 controls mainly the elongation of basal internodes. The C7 allele of qPH8 reduces plant height and increases lodging resistance without yield penalty, suggesting a potential role for qPH8 in improving rice plant architecture.展开更多
A1 doped SmFeO3 （SmFel_xmlxO3; 0.0〈x〈0.15; step 0.05） were prepared by double sintering ceramic technique. The obtained samples were crystallized in single phase structure except the sample with x=0.15. The unit c...A1 doped SmFeO3 （SmFel_xmlxO3; 0.0〈x〈0.15; step 0.05） were prepared by double sintering ceramic technique. The obtained samples were crystallized in single phase structure except the sample with x=0.15. The unit cell volume was found to decrease with increasing AI substitution in orthoferrite. The effective magnetic moment （μeff） and the Curie constant （C） were calculated from the reciprocal of the molar magnetic susceptibility （Z-1） versus absolute temperature plot and found to attain maximum value for the parent sample. The magnetic behavior showed two different magnetic transitions, viz, N6el temperature （TN） and spin reorientation （TsR） transitions. The M-H hysteresis loop of the parent sample took butterfly-shape as a result of different contributions anisotropies. From the magnetic properties measurements, it was obviously found that B-site cation dilution resulted in a drastic decrease in the magnetization. Surprisingly large value of the coercive field was obtained for the undoped sample;Hc=6198.80e. Based on the mentioned results, one can recommend the use of such orthoferrite in magnetic recording media and as pining layer in spin valve for spin- tronic applications.展开更多
A new polyglycerol phthalate extractant was prepared and characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance(~1H NMR) spectroscopy, and thermogravimetric analysis. A prelimin...A new polyglycerol phthalate extractant was prepared and characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance(~1H NMR) spectroscopy, and thermogravimetric analysis. A preliminary study of the extraction of long-lived(^(90) Sr and ^(152+154)Eu) and short-lived(^(90) Y) radionuclides by polyglycerol phthalate was performed. The influence of different diluents, concentration of the acid, type of acid, and various interfering ions was explored. The stripping of ^(152+154)Eu radionuclide was studied by using different acid solutions, and it was found that sulfuric acid was the ideal acid for this purpose. Furthermore,^(152+154)Eu was extracted from the fission products(^(90) Sr) and the extraction% of^(90) Sr was found to improve in the presence of interfering ions.展开更多
Multi-Walled carbon nanotubes are used as preconcentrating probes for the quantitative determination of trace cadmium, copper and lead in environmental and biological sample using graphite Furnace Atomic Absorption Sp...Multi-Walled carbon nanotubes are used as preconcentrating probes for the quantitative determination of trace cadmium, copper and lead in environmental and biological sample using graphite Furnace Atomic Absorption Spectrometry and inductively coupled Plasma Optical Emission spectrometry. The method is based on the electrostatic interactions of positively charged Cd+, Cu+ and Pb+ with the negatively charged multi-walled carbon nanotubes (MWCNTs) for the preconcentration and isolation of analytes from sample solutions. Effective preconcentration of trace cadmium, copper and lead was achieved in a pH range of 5 - 7, 5 - 7 and 4 - 7, respectively. The retained cadmium, copper and lead were efficiently eluted with 0.3 mol·L-1 HCl for graphite Furnace Atomic Absorption Spectrometry determination. The multi-walled carbon nanotubes packed micro-column exhibited fairly fast kinetics for the adsorption of cadmium, copper and lead, permitting the use of high sample flow rates up to at least 3 mL·min-1 for the flow injection on micro-column preconcentration without the loss of the retention efficiency. The detection limits (3σ) were 0.03, 0.01 and 0.5 ng·mL-1 for Cd, Cu and Pb, respectively. The relative standard deviation under optimum condition is less than 2.9% (n = 10). The developed method was successfully applied to the determination of trace Cd, Cu and Pb in a variety of environmental and biological samples.展开更多
Polyvinyl alcohol(PVA) is a well-known friendly polymer for paper-making, textiles, and a variety of coatings, biomedical applications such as artificial pancreas, synthetic vitreous body, wound dressing, artificial s...Polyvinyl alcohol(PVA) is a well-known friendly polymer for paper-making, textiles, and a variety of coatings, biomedical applications such as artificial pancreas, synthetic vitreous body, wound dressing, artificial skin,and cardiovascular device. In this paper, ion/electron beam is employed to get insight into the irradiation effect on surface morphology and optical properties of PVA polymer. UV-Vis spectra are recorded to investigate the effect of induced defects on the optical band gap and the formed carbon clusters size. Scanning electron microscopy(SEM) is used to relate and investigate surface morphology and optical properties of the target polymer with different doses(15, 30 and 60 min). Also, PVA polymer is subjected to theoretical studies by using semi-empirical PM7 quantum chemical method.展开更多
This work is concerned with ion beam dynamics and compares the emittance to aberration ratios of two-and three-electrode extraction systems. The study is conducted with the aid of Version 7 of SIMION 3D ray-tracing so...This work is concerned with ion beam dynamics and compares the emittance to aberration ratios of two-and three-electrode extraction systems. The study is conducted with the aid of Version 7 of SIMION 3D ray-tracing software. The beam dependence on various parameters of the extraction systems is studied and the numerical results lead to qualitative conclusions. Ion beam characteristics using diode and triode extraction systems are investigated with the aid of the computer code SIMION 3 D, Version 7.0. The diode （two electrode extraction system） and triode （three- electrode extraction, acceleration-deceleration system） extraction systems are designed and optimized with different geometric parameters of the electrode system, voltage applied to the extraction electrode, and plasma parameters inside the ion source chamber, as well as by the ion beam space charge. This work attempts to describe the importance of the acceleration-deceleration extraction system. It shows that besides an increase of the beam energy, the ion beam has lower emittance than the two-electrode extraction system. Ion beams of the highest quality are extracted whenever the half-angular divergence is minimum for which the perveance current intensity and the extraction gap have optimum value. Knowing the electron temperature of the plasma is necessary to determine plasma potential and the exact beam energy.展开更多
A translucent wooden substrate with long-lasting phosphorescence,high photostability and durability,tough surface,ultraviolet protection,high optical transmittance,and superhydrophobicity was developed.This long-lasti...A translucent wooden substrate with long-lasting phosphorescence,high photostability and durability,tough surface,ultraviolet protection,high optical transmittance,and superhydrophobicity was developed.This long-lasting phosphorescent wooden substrate is able to continue emitting light for extended time periods.Lignin-modified wood(LMW)was immobilized with a solution of epoxy resin(ER)and rare-earth doped aluminate(REDA)phosphor nanoparticles(NPs).For an improved dispersion of pigment,REDA was synthesized in a nanoscale particle size,and characterized by transmission electron microscopy(TEM)to indicate a particle size of 8-14 nm.The crystal structure of REDA nanoparticles was also proved by X-ray diffraction(XRD).For an improved production of long-persistent phosphorescent colo rless woods,REDA must be well-dispersed in MAA without aggregation.Absorption and emissio n,as well as decay and lifetime spectra were explored.The morphologies of the wooden substrates with different ratios of REDA were investigated by scanning electron microscopy(SEM),X-ray fluorescence(XRF)analysis,Fourier transform infrared spectra(FT-IR),elemental mapping,and energy-dispersion Xray(EDXA).The phosphorescent woods show changes in color from colorless to green under ultraviolet(UV)irradiation,and to yellowish-green in the dark,as proved by the colorimetric parameters of the CIE Lab system.The afterglow wood samples display an absorbance band at 365 nm and two phosphorescent bands at 431 and 520 nm.Improved UV shielding,photostability,and hydrophobicity were explored.With increasing REDA ratio,both static contact and slide angles are found to improve in the ranges of147.6°-163.6°and 9°-14°,respectively.The long-lasting photoluminescence is optimized at a REDA ratio of 8%.The present strategy shows a large-scale production approach of multiple functional woods for many potential applications,such as smart glow in the dark windows and safety signs.展开更多
The impact properties of hot rolled carbon steel （used for the manufacture of reinforcement steel bars） and the quenched ＆ tempered （Q＆T） low alloy steel （used in the pressure vessel industry） were determined....The impact properties of hot rolled carbon steel （used for the manufacture of reinforcement steel bars） and the quenched ＆ tempered （Q＆T） low alloy steel （used in the pressure vessel industry） were determined. The microstructure of the hot rolled carbon steel contained ferrite/pearlite phases, while that of the quenched and tempered low alloy steel contained bainite structure. Impact properties were determined for both steels by instrumented impact testing at temperatures between -150 and 200℃. The impact properties comprised total impact energy, ductile to brittle transition temperature, crack initiation and propagation energy, brittleness transition temperature and cleavage fracture stress. The Q＆T low alloy steel displayed much higher resistance to ductile fracture at high test temperatures, while its resistance to brittle fracture at low test temperatures was a little higher than that of the hot rolled carbon steel. The results were discussed in relation to the difference in the chemical composition and microstructure for the two steels.展开更多
Nuclear fuel performance modeling and simulation are critical tasks for nuclear fuel design optimization and safety analysis under normal and transient conditions.Fuel performance is a complicated phenomenon that invo...Nuclear fuel performance modeling and simulation are critical tasks for nuclear fuel design optimization and safety analysis under normal and transient conditions.Fuel performance is a complicated phenomenon that involves thermal,mechanical,and irradiation mechanisms and requires special multiphysics modules.In this study,a fuel performance model was developed using the COMSOL Multiphysics platform.The modeling was performed for a 2D axis-symmetric geometry of a UO2fuel pellet in the E110 clad for VVER-1200 fuel.The modeling considers all relevant phenomena,including heat generation and conduction,gap heat transfer,elastic strain,mechanical contact,thermal expansion,grain growth,densification,fission gas generation and release,fission product swelling,gap/plenum pressure,and cladding thermal and irradiation creep.The model was validated using a code-to-code evaluation of the fuel pellet centerline and surface temperatures in the case of constant power,in addition to validation of fission gas release(FGR)predictions.This prediction proved that the model could perform according to previously published VVER nuclear fuel performance parameters.A sensitivity study was also conducted to assess the effects of uncertainty on some of the model parameters.The model was then used to predict the VVER-1200 fuel performance parameters as a function of burnup,including the temperature profiles,gap width,fission gas release,and plenum pressure.A compilation of related material and thermomechanical models was conducted and included in the modeling to allow the user to investigate different material/performance models.Although the model was developed for normal operating conditions,it can be modified to include off-normal operating conditions.展开更多
文摘In the present study,the effect of aging heat treatment at 650,750,and 850？C on the impact toughness of 316L austenitic stainless steel,2205 duplex stainless steel and their weldments has been investigated.Welding process was conducted using the TIG（tungsten inert gas） welding technique.Instrumented impact testing,at room temperature,was employed to determine the effect of aging treatment on the impact properties of investigated materials.Aging treatment resulted in degradation in the impact toughness as demonstrated by the reduction in the impact fracture energy and deformation parameters（strain hardening capacity,fracture deffection,and crack initiation and propagation energy）.The degree of embrittlement was more noticeable in duplex stainless steel parent and weld-metal than in 316L stainless steel and became greater with the increase of aging temperature.The degradation in impact toughness was discussed in relation to the observed precipitation of the intermetallic sigma phase in the microstructure of the stainless steel weldments and the corresponding fracture surface morphology.
文摘Cobalt is used in the manufacture of alloys, catalysts in the petroleum industry, catalytic converters, and paint pigments. Thus the potential for Co releases into the environment is highly increased. Use of waste sludges and sewage effluent to fertilize and irrigate soils has also increased soil Co concentrations. Total cobalt contents of alluvial delta soil of Egypt show considerable variation ranging from 13.1 to 64.7 ppm. The impact of either wastewater irrigation or industrial activities on soil total Co was obvious due to accumulation of organic matter and solid waste in the surface soil samples. Food crops and vegetables should not be grown on soil highly contaminated by Co. It is noteworthy that the delayed neutron activation analysis(DNAA) technique could be used successfully for total Co determination due to its high sensitivity. It is quit clearly that dust samples of Cairo City contains higher Co level, as compared to Suez Canal Region(Ismailia, Port Said and El-Suez cities). The high values in Cairo City may be due to the existence of industries around the city and the intensive traffic. To minimize Co environmental hazards, waste effluents should be treated on site. Thus, levels of potentially toxic Co needs to be continuously monitored and should be removed during several treatment processes before the disposal of these wastes.
文摘Extraction of V（V） and Cr（III） from acidic sulfate leach liquors of ilmenite using 0.4 mol/L Aliquat 336 chloride in kerosene was carried out. Different parameters affecting the extraction process such as equilibrium time, sulfate concentration, Aliquat 336 concentration, equilibrium p H and the extraction temperature were investigated. Extraction of V（V） and Cr（III） by Aliquat 336 involved anion exchange mechanism, and the extracted species are [（VO2SO4）R4N]org at low equilibrium p H for V（V） and [R4N-Cr（OH）4]org at high equilibrium p H for Cr（III）. Calculated thermodynamic parameters show that the extraction process is endothermic reaction for V（V） and exothermic for Cr（III）. Also, calculated values of ？Gex and ？Sex indicate that the extraction reactions of V（V） and Cr（III） proceed as non-spontaneous reaction is more random. V（V） and Cr（III） were stripped, precipitated, separated and calcined at 500 °C for 2.0 h to produce the corresponding oxide in pure form after rinsing and drying.
基金the Materials Science Unit,Radiation Physics Department,National Center for Radiation Research and Technology,Egypt,for financing and supporting this study under the project Nanostructured Magnetic Materials。
文摘This paper addresses the manipulation of structural,morphology,optical and magnetic properties of LiCo0.25Zn0.25Fe2 O4 ferrite via incorporation of different proportions of La^3+at the expense of iron ions using a sol-gel method.The samples were characterized using the X-ray diffraction technique(XRD),Fourier transform infrared(FT-IR)spectroscopy,the energy dispersive X-ray spectra(EDX),inductively coupled plasma optical emission spectroscopy(ICP-OES),high resolution scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)surface area analysis,ultraviolet-diffuse reflectance spectroscopy(UV-DRS),and vibrating sample magnetometer(VSM)technique.The Rietveld refinements of the samples indicate that at higher concentrations of La^3+,nanostructures with dual phase,i.e.cubic spinel and orthorhombic LaFeO3 perovskite with space group(Pbnm)appear.Optical studies show that the energy band gap(Eg)of the bare LiCo0.25Zn0.25Fe2 O4 ferrite sample(2.18 eV)reaches up to 2.47 eV at x=0.06 and above this concentration,it drops sharply to 2.00 eV.Although the saturation magnetization and the coercivity of LiCo0.25Zn0.25LaxFe2-xO4 are lower than that of LiCo0.25Zn0.25Fe2 O4 NPs.Overall,the superparamagnetic nature and low values of saturation magnetization and coercivity of LiCo0.25Zn0.25LaxFe2-xO4 NPs are suitable to be applied in transformers core.
文摘Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room temperature.Potentiodynamic results showed that 6% Mo alloy possessed a remarkable resistance to crevice corrosion compared with 316L alloy when they are tested in the same solution. The breakdown potential at which passivity broke down for 316L alloy was 0.00 mV （SCE）. The corresponding value for 6% Mo alloy could not reach up to the potential value of 700 mV （SCE）. 316L alloy suffered extremely from crevice corrosion at room temperature （about 25℃）, which indicates that the critical crevice corrosion temperature, below which crevice corrosion does not occur, was lower than the test temperature. For 6% Mo alloy, the critical crevice corrosion temperature was higher than the testing temperature. Electrochemical parameters indicated that 6% Mo alloy exhibited higher crevice corrosion resistance than 316L alloy.
文摘The solvent extraction of Pr(Ⅲ) and Sm(Ⅲ) with trialkyl phosphine oxide(Cyanex 923) in chloroform,carbon tetrachloride,n-octane,cyclohexane,1,2-dichloroethane,benzene,toluene,xylene and nitrobenzene from acidic nitrate medium was investigated.On the basis of slope analysis data,the composition of the extracted species was determined as(M(NO3)3?2CY923),CY923 refers to Cyanex 923.The values of the equilibrium constants and the separation factors were calculated.The effect of the diluents on the metal extracti...
文摘Objective:To assess the hepatoprotective effects of flavone on nicotine-induced liver damage.Methods:Thirty-six rats were allocated into six groups:the control group,the nicotine group,the flavone alone groups(10 and 25 mg/kg/body weight),and the nicotine groups treated with flavone(10 and 25 mg/kg/body weight).Liver function,oxidative stress,Nrf2 pathway(HO-1,Nrf2,and Keap-1),and inflammatory markers(IL-17,TNF-α,and NF-κB)were evaluated.Additionally,a histopathological examination of liver tissues was performed.Results:Nicotine increased liver damage,inflammation,and oxidative stress.However,flavone suppressed nicotine-induced liver enzymes,oxidative stress,and inflammation,as manifested by increased antioxidants and decreased malondialdehyde level,liver enzymatic activities,and inflammatory markers.Flavone(10 and 25 mg/kg/body weight)also reduced the level of Keap-1 and increased HO-1 and Nrf2 levels in the liver of nicotine-exposed rats.Conclusions:Flavone has hepatoprotective properties and may slow the progression of liver injury by reducing oxidative stress,liver enzymes,and inflammation possibly via the Nrf2 pathway.
文摘BACKGROUND Hepatitis C virus(HCV),hepatitis B virus(HBV),and human immunodeficiency virus 1(HIV-1)are the most epidemic blood-borne viruses,posing threats to human health and causing economic losses to nations for combating the infection transmission.The diagnostic methodologies that depend on the detection of viral nucleic acids are much more expensive,but they are more accurate than sero-logical testing.AIM To develop a rapid,cost-effective,and accurate diagnostic multiplex polymerase chain reaction(PCR)assay for simultaneous detection of HCV,HBV,and HIV-1.METHODS The design of the proposed PCR assay targets the amplification of a short conserved region featured with a distinguishable melting profile and electro-phoretic molecular weight inside each viral genome.Therefore,this diagnostic method will be appropriate for application in both conventional(combined with electrophoresis)and real-time PCR facilities.Confirmatory in silico investigations were conducted to prove the capability of the approached PCR assay to detect variants of each virus.Then,Egyptian isolates of each virus were subjected to the wet lab examination using the given diagnostic assay.RESULTS The in silico investigations confirmed that the PCR primers can match many viral variants in a multiplex PCR assay.The wet lab experiment proved the efficiency of the assay in distinguishing each viral type through high-resolution melting analysis.Compared to related published assays,the proposed assay in the current study is more sensitive and competitive with many expensive PCR assays.CONCLUSION This study provides a simple,cost-effective,and sensitive diagnostic PCR assay facilitating the detection of the most epidemic blood-borne viruses;this makes the proposed assay promising to be substitutive for the mistakable and cheap serological-based assays.
文摘Metal-substituted cobalt ferrites [MxCo(1-x)Fe2O4(M=Zn,Cu,Mn;x=0.0,0.25,0.5,and 0.75)]were synthesized via a sol-gel technique.The ferrite structures were confirmed by X-ray diffraction, Fourier transform infrared spectroscopy,scanning electron microscopy,surface analysis using the Brunauer-Emmett-Teller method,and energy-dispersive X-ray spectroscopy.Antimicrobial activity of these ferrites against selected pathogenic microbes was determined.The structures remained cubic spinel phases after substitution of metals.Substitution strongly influenced the microstructure and homoge- neous grain distribution.The particle size of the ferrites increased linearly with increase in their annealing temperature.The surface area of zinc cobalt ferrite nanoparticles (ZCFO)was 52.56m^2/g,the average pore size was 1.84nm,and pore volume was 0.136mL/g.All ferrites showed antimicrobial activity toward all pathogens selected.Of these,the most powerful was ZCFO,showing zones of inhibition of 13.0mm against Bacillus subtilis and Staphylococcus aureus and 12.0mm against Candida albicans.Gamma-irradiated ZCFO nanoparticles (150.0kGy)maintained higher antimicrobial activity than non-irradiated particles,e.g. being active toward S.aureus (16.0mm).ZCFO is proposed as a candidate material for industrial and biomedical purposes.
文摘A procedure for radioiodination of valsartan with iodine-125 is carried out via an electrophilic substitution of hydrogen atom with the iodonium cation I+. All reaction parameters were studied to optimize the labeling conditions of valsartan and to obtain a maximum radiochemical yield (RCY) of the 125I-Valsartan [125I-Val]. By using 3.7 MBq of Na125I, 50 μg of valsartan (0.2 mM) as substrate, 25 μg of Iodogen (0.15 mM) as oxidizing agent in ethanol at room temperature for 30 min, the radiochemical yield of 125I-Val was 98.6% The radiochemical yield was determined by electrophoresis using cellulose acetate moistened with 0.02 M phosphate buffer pH 7. The labeled compound was separated and purified by means of high-pressure liquid chromatography (HPLC). The biological distribution in normal mice indicates the suitability of radioiodinated valsartan to image any cardiovascular disorders.
基金supported by STI2030-Major Projects (2023ZD0406802)the Fundamental Research Funds for the Central Universities (2662020ZKPY002)+1 种基金the National Key Laboratory of Crop Genetic Improvement Self-Research Program (ZW19A0201)the HZAUAGIS Cooperation Fund 869 (SZYJY2021006).
文摘Spike architecture influences both grain weight and grain number per spike,which are the two major components of grain yield in bread wheat(Triticum aestivum L.).However,the complex wheat genome and the influence of various environmental factors pose challenges in mapping the causal genes that affect spike traits.Here,we systematically identified genes involved in spike trait formation by integrating information on genomic variation and gene regulatory networks controlling young spike development in wheat.We identified 170 loci that are responsible for variations in spike length,spikelet number per spike,and grain number per spike through genome-wide association study and meta-QTL analyses.We constructed gene regulatory networks for young inflorescences at the double ridge stage and thefloret primordium stage,in which the spikelet meristem and thefloret meristem are predominant,respec-tively,by integrating transcriptome,histone modification,chromatin accessibility,eQTL,and protein–pro-tein interactome data.From these networks,we identified 169 hub genes located in 76 of the 170 QTL regions whose polymorphisms are significantly associated with variation in spike traits.The functions of TaZF-B1,VRT-B2,and TaSPL15-A/D in establishment of wheat spike architecture were verified.This study provides valuable molecular resources for understanding spike traits and demonstrates that combining genetic analysis and developmental regulatory networks is a robust approach for dissection of complex traits.
基金partially supported by the National Natural Science Foundation of China(31701391)the National Key Laboratory of Crop Genetic Improvement Self-Research Program(ZW18B0101)。
文摘Bulked-segregant analysis is a time-and cost-saving strategy for identifying major quantitative trait loci(QTL) in a mapping population. Bulked-segregant analysis combined with whole-genome sequencing(BSA-seq) was performed to rapidly identify QTL for heading date, plant height, and panicle length in a large F_(2) population derived from two landraces: Chuan 7(C7) and Haoboka(HBK). Twenty plants with extremely low or high phenotypic values for the target traits were selected from an F_(2) population of 940 plants to construct low-and high-value bulks. Three pairs of bulks for the three traits were constructed, resulting in six DNA pools. BSA-seq revealed nine QTL: four for heading date, three for plant height, and two for panicle length. These QTL were validated in a random F_(2) population or BC_(4)F_(2) populations. The major novel plant height QTL, qPH8, acting additively with an effect equivalent to that of semi-dwarf 1(sd1), is potentially valuable for hybrid rice breeding. qPH8 controls mainly the elongation of basal internodes. The C7 allele of qPH8 reduces plant height and increases lodging resistance without yield penalty, suggesting a potential role for qPH8 in improving rice plant architecture.
文摘A1 doped SmFeO3 （SmFel_xmlxO3; 0.0〈x〈0.15; step 0.05） were prepared by double sintering ceramic technique. The obtained samples were crystallized in single phase structure except the sample with x=0.15. The unit cell volume was found to decrease with increasing AI substitution in orthoferrite. The effective magnetic moment （μeff） and the Curie constant （C） were calculated from the reciprocal of the molar magnetic susceptibility （Z-1） versus absolute temperature plot and found to attain maximum value for the parent sample. The magnetic behavior showed two different magnetic transitions, viz, N6el temperature （TN） and spin reorientation （TsR） transitions. The M-H hysteresis loop of the parent sample took butterfly-shape as a result of different contributions anisotropies. From the magnetic properties measurements, it was obviously found that B-site cation dilution resulted in a drastic decrease in the magnetization. Surprisingly large value of the coercive field was obtained for the undoped sample;Hc=6198.80e. Based on the mentioned results, one can recommend the use of such orthoferrite in magnetic recording media and as pining layer in spin valve for spin- tronic applications.
文摘A new polyglycerol phthalate extractant was prepared and characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance(~1H NMR) spectroscopy, and thermogravimetric analysis. A preliminary study of the extraction of long-lived(^(90) Sr and ^(152+154)Eu) and short-lived(^(90) Y) radionuclides by polyglycerol phthalate was performed. The influence of different diluents, concentration of the acid, type of acid, and various interfering ions was explored. The stripping of ^(152+154)Eu radionuclide was studied by using different acid solutions, and it was found that sulfuric acid was the ideal acid for this purpose. Furthermore,^(152+154)Eu was extracted from the fission products(^(90) Sr) and the extraction% of^(90) Sr was found to improve in the presence of interfering ions.
文摘Multi-Walled carbon nanotubes are used as preconcentrating probes for the quantitative determination of trace cadmium, copper and lead in environmental and biological sample using graphite Furnace Atomic Absorption Spectrometry and inductively coupled Plasma Optical Emission spectrometry. The method is based on the electrostatic interactions of positively charged Cd+, Cu+ and Pb+ with the negatively charged multi-walled carbon nanotubes (MWCNTs) for the preconcentration and isolation of analytes from sample solutions. Effective preconcentration of trace cadmium, copper and lead was achieved in a pH range of 5 - 7, 5 - 7 and 4 - 7, respectively. The retained cadmium, copper and lead were efficiently eluted with 0.3 mol·L-1 HCl for graphite Furnace Atomic Absorption Spectrometry determination. The multi-walled carbon nanotubes packed micro-column exhibited fairly fast kinetics for the adsorption of cadmium, copper and lead, permitting the use of high sample flow rates up to at least 3 mL·min-1 for the flow injection on micro-column preconcentration without the loss of the retention efficiency. The detection limits (3σ) were 0.03, 0.01 and 0.5 ng·mL-1 for Cd, Cu and Pb, respectively. The relative standard deviation under optimum condition is less than 2.9% (n = 10). The developed method was successfully applied to the determination of trace Cd, Cu and Pb in a variety of environmental and biological samples.
文摘Polyvinyl alcohol(PVA) is a well-known friendly polymer for paper-making, textiles, and a variety of coatings, biomedical applications such as artificial pancreas, synthetic vitreous body, wound dressing, artificial skin,and cardiovascular device. In this paper, ion/electron beam is employed to get insight into the irradiation effect on surface morphology and optical properties of PVA polymer. UV-Vis spectra are recorded to investigate the effect of induced defects on the optical band gap and the formed carbon clusters size. Scanning electron microscopy(SEM) is used to relate and investigate surface morphology and optical properties of the target polymer with different doses(15, 30 and 60 min). Also, PVA polymer is subjected to theoretical studies by using semi-empirical PM7 quantum chemical method.
文摘This work is concerned with ion beam dynamics and compares the emittance to aberration ratios of two-and three-electrode extraction systems. The study is conducted with the aid of Version 7 of SIMION 3D ray-tracing software. The beam dependence on various parameters of the extraction systems is studied and the numerical results lead to qualitative conclusions. Ion beam characteristics using diode and triode extraction systems are investigated with the aid of the computer code SIMION 3 D, Version 7.0. The diode （two electrode extraction system） and triode （three- electrode extraction, acceleration-deceleration system） extraction systems are designed and optimized with different geometric parameters of the electrode system, voltage applied to the extraction electrode, and plasma parameters inside the ion source chamber, as well as by the ion beam space charge. This work attempts to describe the importance of the acceleration-deceleration extraction system. It shows that besides an increase of the beam energy, the ion beam has lower emittance than the two-electrode extraction system. Ion beams of the highest quality are extracted whenever the half-angular divergence is minimum for which the perveance current intensity and the extraction gap have optimum value. Knowing the electron temperature of the plasma is necessary to determine plasma potential and the exact beam energy.
基金support and funding of King Khalid University through Research Center for Advanced Materials Science(RCAMS)under grant no:RCAMS/KKU/008/21the support provided by King Abdullah City for Atomic and Renewable Energy(K.A.CARE)under K.A.CARE-King Abdulaziz University Collaboration Program。
文摘A translucent wooden substrate with long-lasting phosphorescence,high photostability and durability,tough surface,ultraviolet protection,high optical transmittance,and superhydrophobicity was developed.This long-lasting phosphorescent wooden substrate is able to continue emitting light for extended time periods.Lignin-modified wood(LMW)was immobilized with a solution of epoxy resin(ER)and rare-earth doped aluminate(REDA)phosphor nanoparticles(NPs).For an improved dispersion of pigment,REDA was synthesized in a nanoscale particle size,and characterized by transmission electron microscopy(TEM)to indicate a particle size of 8-14 nm.The crystal structure of REDA nanoparticles was also proved by X-ray diffraction(XRD).For an improved production of long-persistent phosphorescent colo rless woods,REDA must be well-dispersed in MAA without aggregation.Absorption and emissio n,as well as decay and lifetime spectra were explored.The morphologies of the wooden substrates with different ratios of REDA were investigated by scanning electron microscopy(SEM),X-ray fluorescence(XRF)analysis,Fourier transform infrared spectra(FT-IR),elemental mapping,and energy-dispersion Xray(EDXA).The phosphorescent woods show changes in color from colorless to green under ultraviolet(UV)irradiation,and to yellowish-green in the dark,as proved by the colorimetric parameters of the CIE Lab system.The afterglow wood samples display an absorbance band at 365 nm and two phosphorescent bands at 431 and 520 nm.Improved UV shielding,photostability,and hydrophobicity were explored.With increasing REDA ratio,both static contact and slide angles are found to improve in the ranges of147.6°-163.6°and 9°-14°,respectively.The long-lasting photoluminescence is optimized at a REDA ratio of 8%.The present strategy shows a large-scale production approach of multiple functional woods for many potential applications,such as smart glow in the dark windows and safety signs.
文摘The impact properties of hot rolled carbon steel （used for the manufacture of reinforcement steel bars） and the quenched ＆ tempered （Q＆T） low alloy steel （used in the pressure vessel industry） were determined. The microstructure of the hot rolled carbon steel contained ferrite/pearlite phases, while that of the quenched and tempered low alloy steel contained bainite structure. Impact properties were determined for both steels by instrumented impact testing at temperatures between -150 and 200℃. The impact properties comprised total impact energy, ductile to brittle transition temperature, crack initiation and propagation energy, brittleness transition temperature and cleavage fracture stress. The Q＆T low alloy steel displayed much higher resistance to ductile fracture at high test temperatures, while its resistance to brittle fracture at low test temperatures was a little higher than that of the hot rolled carbon steel. The results were discussed in relation to the difference in the chemical composition and microstructure for the two steels.
基金The Science,Technology&Innovation Funding Authority(STDF)in cooperation with The Egyptian Knowledge Bank(EKB).
文摘Nuclear fuel performance modeling and simulation are critical tasks for nuclear fuel design optimization and safety analysis under normal and transient conditions.Fuel performance is a complicated phenomenon that involves thermal,mechanical,and irradiation mechanisms and requires special multiphysics modules.In this study,a fuel performance model was developed using the COMSOL Multiphysics platform.The modeling was performed for a 2D axis-symmetric geometry of a UO2fuel pellet in the E110 clad for VVER-1200 fuel.The modeling considers all relevant phenomena,including heat generation and conduction,gap heat transfer,elastic strain,mechanical contact,thermal expansion,grain growth,densification,fission gas generation and release,fission product swelling,gap/plenum pressure,and cladding thermal and irradiation creep.The model was validated using a code-to-code evaluation of the fuel pellet centerline and surface temperatures in the case of constant power,in addition to validation of fission gas release(FGR)predictions.This prediction proved that the model could perform according to previously published VVER nuclear fuel performance parameters.A sensitivity study was also conducted to assess the effects of uncertainty on some of the model parameters.The model was then used to predict the VVER-1200 fuel performance parameters as a function of burnup,including the temperature profiles,gap width,fission gas release,and plenum pressure.A compilation of related material and thermomechanical models was conducted and included in the modeling to allow the user to investigate different material/performance models.Although the model was developed for normal operating conditions,it can be modified to include off-normal operating conditions.
