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Thermomechanical treatment of austempered ductile iron

China Foundry 2007年第4期4卷 304-309页

作者： A.A.Nofal h.nasr el-din M.M.Ibrahim Central Metallurgical Research and Development Institute (CMRDI)CairoEgypt

The production of lightweight ferrous castings with increased strength properties became unavoidable facing the serious challenge of lighter aluminum and magnesium castings. The relatively new ferrous casting alloy ADI offers promising strength prospects, and the thermo-mechanical treatment of ductile iron may suggest a new route for production of thin-wall products. This work aims at studying the influence of thermomechanical treatment, either by ausforming just after quenching and before the onset of austempering reaction or by cold rolling after austempering. In the first part of this work, ausforming of ADI up to 25% reduction in height during a rolling operation was found to add a mechanical processing component compared to the conventional ADI heat treatment, thus increasing the rate of ausferrite formation and leading to a much finer and more homogeneous ausferrite product. The kinetics of ausferrite formation was studied using both metallographic as well as XRD-techniques. The effect of ausforming on the strength was quite dramatic （up to 70% and 50% increase in the yield and ultimate strength respectively）. A mechanism involving both a refined microstructural scale and an elevated dislocation density was suggested. Nickel is added to ADI to increase hardenability of thick section castings, while ausforming to higher degrees of deformation is necessary to alleviate the deleterious effect of alloy segregation on ductility. In the second part of this work, the influence of cold rolling （CR） on the mechanical properties and structural characteristics of ADI was investigated. The variation in properties was related to the amount of retained austenite （7~） and its mechanically induced transformation. In the course of tensile deformation of ADI, transformation induced plasticity （TRIP） takes place, indicated by the increase of the instantaneous value of strain-hardening exponent with tensile strain. The amount of retained austenite was found to decrease due to

关键词： ADI ausforming cold-rolling thermomechanical treatment transformation induced plasticity

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Mossbauer,optical and structural properties of Fe^(3+) ion in borate glass

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Journal of Rare Earths 2025年第1期43卷 162-170,I0006页

作者： Essam A.elkelany hesham Y.Amin A.Samir M.M.el-hady h.h.el-Bahnasawy Moukhtar A.hassan Basic Science Department Faculty of EngineeringSinai UniversityAl-Arish45511Egypt School of Information and electrical Engineering Hangzhou City UniversityHangzhou30015China State Key Laboratory of Modern Optical Instrumentation College of Optical Science and EngineeringZhejiang UniversityHangzhou310027China Basic Science Department Faculty of Engineering at ShoubraBenha University11629Egypt Physics Department Faculty of ScienceAl-Azhar University11884CairoEgypt

Lanthanum-bearing iron lithium borate glass is a quaternary system for oxide glasses and was prepared via the melt-quenching *** present article correlates the structure,optical,ligand field and M?ssbauer data on iron lithium borate glass co ntaining La^(3+).The density was measured,while the molar volume was *** physical parameters are *** increasing the La_(2)O_(3) content within the glass network,infrared spectra analysis reveals structural modifications such as the increase in BO_(4) units and the decline in both BO_(3) units and NBO bonds ***,optical absorption spectra were *** absorption spectra disclose a plethora of electronic transitions that are related to Fe^(3+)in tetrahedral and octahedral sites,however,Fe^(2+)phase is not observed in optical spectra,but it has a clear signature in M?ssbauer ***,the glass absorption edges undergo a clear blue shift,reflecting an increased band gap energy(1.96-2.28 eV).The decline in NBO bonds justifies this ***,the values of crystal field splitting are increased,while the values of Racah parameters are *** trend is justified by the decline in NBO bonds and increases electron localization around Fe cations.M?ssbauer spectra confirm the existence of Fe^(3+)in tetrahedral and octahedral sites,while Fe^(2+)exists in only a tetrahedral *** increasing La_(2)O_(3) content,the isomer shift of Fe^(3+)in tetrahedral sites changes to be 0.312-0.329 mm/s,while the isomer shift of octahedral Fe^(3+)is 0.424-0.456 mm/*** findings coincide with optical *** the isomer shift of tetrahedral Fe^(2+)is 0.902-0.911 mm/*** results of structural,optical and ligand field associated with M?ssbauer spectra open more vistas toward the utility of these samples in the optics realm.

关键词： Fe3+ions Rare-earth oxide Mossbauer spectra Ligand field parameters Optical properties

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Thermal effects on wear behavior of additively manufactured NiTi shape memory alloys

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Chinese Journal of Aeronautics 2025年第1期38卷 147-164页

作者： Xianghui hUANG Nan KANG Pei WANG Mohamed el MANSORI Arts et Metiers Institute of Technology MSMPHESAM UniversitéChâlons-en-Champagne 51006France henan Key Laboratory of high-Performance Carbon Fiber Reinforced Composites Institute of Carbon Matrix CompositesHenan Academy of SciencesZhengzhou 450046China Texas A&M Engineering Experiment Station Institute for Manufacturing SystemsCollege StationTX 77843USA

NiTi alloys fabricated by laser powder bed fusion(LPBF)additive manufacturing technology not only address the compositional instability resulting from complex processes but also solve the challenges of difficult machining of intricate aerospace ***,there are very few reports on the wear behavior of LPBF-NiTi *** the present work,the effects of microstructure and thermal treatment,including heat treatment and frictional heat,on the wear behavior of LPBF-NiTi alloy and 100Cr6 ball were analyzed through a series of tribological experiments with different sliding *** the average sliding speed increases(0.079–0.216 m/s),the wear rate of the as-built and heat-treated samples tends to decrease in the range of 2.69×10^(-3)–0.97×10^(-3)mm^(3)/*** the heat-treated LPBF-NiTi alloy is 46%harder than the as-built alloy is,the latter has a higher toughness(505 MJ/m^(3))and greater transformation strain of SIM(0.097).This leads to a coupling effect of heat treatment and sliding speed on the wear *** addition,the wear track morphologies under different sliding speeds are asymmetric due to the 24% greater acceleration at the far end from the motor and the 2.15 mm deviation between the maximum speed position and the geometric center of the *** wear modes of the as-built and heat-treated samples included adhesive,abrasive and delamination ***,the wear morphologies and dominant wear modes change with the frictionally caused heat release induced by the sliding speed.

关键词： Additive manufacturing Laser powder bed fusion NiTi alloys Wear resistance Sliding speed

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Thermal oil recovery factors from sandpacks of variable mineralogy

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Petroleum Research 2023年第4期8卷 481-489页

作者： Viacheslau Y.Kudrashou hisham A.nasr-el-din Slippery Rock University United States Texas A&M University United States

S Steam injection is commonly used for production of viscous crude *** rock often contains clay *** nature of steam and clay minerals may lead to formation *** work in-vestigates oil recovery and changes in petrophysical properties as a function of the ***-packs with quartz,calcite,feldspar,kaolinite,smectite,and illite were prepared for steam injection *** of the steamed sandpacks was determined using coreflood *** composition of the produced aqueous samples was determined using ICP-OES(inductively coupled plasma-optical emission spectroscopy).Morphology of the rock samples was studied using SEM-EDs(scanning electron microscope-energy dispersive X-ray spectroscopy).Mineralogy and elemental content of the solid samples were determined using XRD(X-ray diffraction)analysis and XRF(X-ray fluorescence)*** was found that aqueous phase samples produced from clay-rich sandpacks tend to have higher ph than samples produced from samples without clay *** recovery factors for 100%quartz case was determined to be 65 wt%.Calcite-and feldspar-rich sandpacks produced 56 and 61 wt%of oil *** with clay fractions have shown the lowest oil recovery-39,29,and 28 wt%for kaolinite-,smectite-,and illite-rich samples *** dissolution and pre-cipitation were the dominant damaging mechanism for quartz and calcite ***-rich sandpack demonstrated signs of structural destruction of the mineral and fines ***'s effect on oil recovery was found to be associated with fines *** hydration and swelling in presence of steam was the dominant formation damage effect on the oil *** interaction with illite-rich sandpack caused formation of amorphous *** paper presents oil recovery factors as a function of injected pore volume(PV)of steam for sandpacks of different *** results characterize petroph

关键词： Steam injection Oilrecovery Kaolinite Smectite Ilite Sandpack

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Effects of rare-earth Pr3+-Dy3+ doping on structural,magnetic,optical and dielectric properties of Zn2Y hexaferrite

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Journal of Rare Earths 2025年第2期43卷 329-336页

作者： Ibrahim Mohammed Mohamed E.el Sayed Ali Shawabkeh Mohammad N.Murshed Ibtehaj F.Alshdoukhi Zeinhom M.el-Bahy J.Mohammed A.K.Srivastava Department of Physics Lovely Professional University Department of Science Technology Waziri Umaru Federal Polytechnic Birnin Kebbi Physics Department Faculty of Science and ArtsKing Khalid University College of Engineering and Technology American University of the Middle East Department of Basic Sciences College of Science and Health ProfessionsKing Saud Bin Abdulaziz University for Health ScienceKing Abdullah International Medical Research Center Department of Chemistry Faculty of ScienceAl-Azhar University Department of Physics Faculty of ScienceFederal University Dutse

This study was conducted to investigate the properties of Pr3+-Dy3+doped Zn2Y-type hexaferrite for potential technological applications.X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR） and field-emission scanning electron microscopy（FESEM） were used to analyze structural *** crystallite size in the synthesized samples varies between 57.54 and 68.57 *** vibrational bands at 400 and 600 cm-1,common to all hexaferrites,were confirmed through *** FESEM analysis reveals an agglomeration of magnetic grains and a decrease in the average grain size from 1.24 to1.06 μ*** M-h loops show that,with x values of 0.0,0.1,and 0.2,the saturation magnetization is determined to be 34.76,34.23,and 32.52 emu/g,*** corresponding coercivity values are21.24,30.39,and 33.99 ***-visible spectroscopy using Tauc theory reveals an increase in the optical band gap from 2.32 to 2.50 eV,indicating a tunable energy band structure by incorporating Pr3+-Dy3+*** dielectric constant increases,whereas AC conductivity decreases with increased Pr3+-Dy3+*** obtained results suggest the potential suitability of these materials for various technological applications.

关键词： Dielectric constant Magnetic hysteresis Optical band gap Pr3+-Dy3+ Rare earths Zn2Y-type hexaferrite

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Role of Right Ventricular-Pulmonary Arterial Coupling Measured by Echocardiography in Predicting Right Ventricular Dysfunction after Cardiac Surgery

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World Journal of Cardiovascular Surgery 2025年第1期15卷 1-11页

作者： Ismail nasr el-Sokkary Esam Ahmed Khalil Mohammed Fawzy eltaweel Ahmed Alherazi Mohammed Samy Bahaa Abdelgawad elkhonezy Mohamed el Sayed Moussa Mohamed Ahmed Mosaad Zaki Ibrahim Abdel Fattah Yassin Mohamed Kamal Rehan Department of Cardiothoracic Surgery Faculty of Medicine Al-Azhar University Cairo Egypt Department of Cardiology Al-Azhar University Faculty of Medicine Cairo Egypt Department of Cardiothoracic Surgery Faculty of Medicine Menoufia University Shibin El Kom Egypt Department of Cardiothoracic Surgery Faculty of Medicine Alexandria University Alexandria Egypt Department of Internal Medicine Faculty of Medicine Beni Suef University Cairo Egypt

Background: The tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) is an indirect estimate of right ventricular-pulmonary arterial (RV-PA) coupling that has been shown to correlate with invasive measures. We aimed to assess the ability of the tricuspid annular plane systolic excursion/pulmonary systolic pressure ratio (TAPSE/PASP) as a measure for RV-PA coupling to predict the development of RV dysfunction after cardiac surgery. Methods: This prospective study was conducted on 100 patients with ischemic heart disease and undergoing cardiac surgery (coronary artery bypass graft (CABG)) with normal preoperative right ventricular function, classified according to RV function outcomes into 2 groups: Normal RV group (65 patients) and RV dysfunction group (35 patients). All cases underwent per and postoperative transthoracic echocardiography. Results: By using receiver operating characteristic curve analysis, pre-operative TAPSE/PASP ratio could significantly predict the RV dysfunction (P 0.58, with AUC of 94%, 88.6% sensitivity, and 89.2% specificity. Post-operative TAPSE/PASP Ratio could significantly predict the RV dysfunction (P 0.39, with AUC of 84%, 100% sensitivity, and 76.9% specificity. Pre-operative TAPSE/PASP ratio could significantly predict mortality (P Conclusion: The TAPSE/PASP ratio is an excellent tool for CABG patients for its ability to detect and predict the development of RV dysfunction after cardiac surgery, along with the prediction of mortality in post-operative CABG patients.

关键词： Right Ventricular Pulmonary Arterial Coupling Echocardiography Cardiac Surgery

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New insights into hydraulic fracturing fluids used for hightemperature wells

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Petroleum 2021年第1期7卷 70-79页

作者： Tariq Almubarak Leiming Li Jun hong Ng hisham nasr-el-din Mohammed AlKhaldi Texas A&M University USA Aramco Services Company Saudi Arabia Saudi Aramco EXPEC ARC Saudi Arabia

Current interest in deep,low-permeability formations(<10 md)demands accelerated development of high-temperature hydraulic fracturing *** guar systems break down above 300°F and require higher polymer loadings to main... 详细信息

Current interest in deep,low-permeability formations(elerated development of high-temperature hydraulic fracturing *** guar systems break down above 300°F and require higher polymer loadings to maintain thermal ***,higher polymer loadings generate more residue and damage to the proppant pack and the *** resolve these problems,a variety of high-temperature stabilizers are added to enhance the thermal stability of these fracturing fluids at temperatures above 300*** focus of this work is to:(1)identify those additives that best enhance temperature stability of fracturing fluids and(2)study the rheological influence of incorporating these additives on the fracturing fluid *** experimental fracturing-fluid solutions were prepared at a total polymer concentration of 30 and 40 lb/1000 *** such as synthetic polymer,oxygen scavengers,crosslinkers,crosslinker delay additives,and ph buffers were examined in this *** polymer solutions were crosslinked with a metallic crosslinker between 200 and 400°*** measurements were carried out in a highpressure/high-temperature(hP/hT)rheometer to evaluate rheology and thermal *** show that adding a synthetic polymer and a crosslinker with the slowest reaction rate improves the fracturing fluid thermal *** the three other additives tested,oxygen scavengers showed the greatest enhancement to thermal stability while ph buffers showed the *** the addition of high-temperature stabilizing additives,the fracturing fluid in this work was able to maintain a stable performance at temperatures up to 400°*** the thermal stability of fracturing fluids at a lower polymer loading remains a challenge in the *** work proposes techniques that can be used to enhance the thermal stability of fracturing *** knowledge about these different techniques will allow for better additive development and a

关键词： Oxygen scavenger Crosslinker Crosslinker delay Shear tolerance high temperature Synthetic polymer CMhPG Buffers

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Evaluation of the Effectiveness of Traditional and Nano Materials Used in Consolidation of Sandstone Used in Ramesses III Temple, Karnak, Egypt

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Journal of Minerals and Materials Characterization and Engineering 2025年第1期13卷 18-30页

作者： Essam h. Mohamed Zeinab Mahmoud Ahmed Mahmoud L. Abd el-Latif Department of Archaeological Conservation Faculty of Archaeology South Valley University Qena Egypt Department of Conservation Faculty of Archaeology South Valley University Qena Egypt housing and Building Research Center Giza Egypt

This experimental study assesses the effectiveness of traditional and nano-materials in enhancing the physical and mechanical properties of deteriorated sandstone from Ramesses III Temple, Karnak, Luxor, Egypt. Treatments included Nano Estel (5%), Paraloid B-72 (3%), Paraloid B-72/Nano Estel (3%/5%), and ethyl silicates. Treated samples underwent Scanning electron Microscopy (SEM) and physical/mechanical testing. Results show that Paraloid B-72/Nano Estel (3%/5%) yielded optimal consolidation, significantly improving sandstone’s physical and mechanical properties.

关键词： Ramesses III Temple Deteriorated Sandstone Consolidation Treatments Nano Material Physical and Mechanical Properties

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Characterization and Catalytic Activity of New Metal-organic Frameworks Resulted from Self-assembly of Ph3SnCI, K[Cu（CN）2] and Nitrogen Donor Ligands

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Chinese Journal of Chemistry 2011年第7期29卷 1401-1410页

作者： Etaiw, Safaa el-din h. elsherbiny, Abeer S. Badr el-din, Ahmed S. Chemistry Department Faculty of Science Tanta University Tanta Egypt

Five new metal-organic frameworks （MOFs） of the general composition [Ph3SnCu（CN）2.L], where L= pyrazine （pyz）（1）, methylpyrazine （mepyz）（2）, 4,4＇-bipyridine （bpy）（3）, trans-l,2-bis（4-pyridyl）ethene （tbpe）（4） or 1,2-bis（4-pyridyl）ethane （bpe）（5）, have been synthesized and characterized to test their potential applications as catalysts. The structures of the MOFs 1--5 mainly consist of Cu（CN）2 building blocks connected by the Ph3Sn cations and the bipodal ligand forming polymeric networks. They exhibit strong fluorescence in the solid state. Also, they are used as heterogeneous catalysts for the degradation of azo-dyes, metanil yellow （MY） by diluted solution of hydrogen peroxide as oxidant. The reaction is first order with respect to MY dye, while the factors affecting the rate constant of the degradation reaction are investigated. The activation parameters of the reaction have been estimated and a possible mechanism has been proposed.

关键词： copper tin heterogeneous catalyst metanil yellow hydrogen peroxide

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hematobiochemical and histopathological alterations in Nile Tilapia(Oreochromis niloticus)exposed to ethidium bromide:The protective role of Spirulina platensis

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Aquaculture and Fisheries 2024年第1期9卷 93-103页

作者： Sabreen Abdullah Mervat Naguib Alaa el-din Salah el-din Alaa el-din h.Sayed Zoology Department Faculty of ScienceAswan UniversityAswan81528Egypt Zoology Department Faculty of ScienceAssuit UniversityAssiut71516Egypt

Ethidium bromide(EtBr)is one of the contaminants recorded in aquatic environments whose effects have been investigated;however,there is still limited knowledge about its *** study examined the potential protective effects of Spirulina platensis(SP)against the effects of EtBr toxicity in the Nile tilapia(Oreochromis niloticus)*** were divided to five groups,viz.,a control and four treatment groups of low-dose EtBr(10μg/L),low-dose EtBr with SP(10μg/L EtBr+200 mg/L SP),high-dose EtBr(100μg/L),and high-dose EtBr with SP(100μg/L EtBr+200 mg/L SP);the exposure period was 2 *** and high doses of EtBr induced alterations in some hematological,biochemical,and histopathological *** hepatocytes,degenerated area,vacuolated hepatocytes,pyknotic nuclei,constricted and dilated blood sinusoids,and infiltration of inflammatory cells were *** peroxidation concentration was not significantly different in groups exposed to low doses of EtBr and EtBr with SP,but it was increased in groups exposed to high doses of EtBr and EtBr with SP,compared with the control *** feeding with SP,most histological and histochemical parameters restored to normal ***,SP may possess the ability to preserve the structural integrity of the hepatic and renal membranes.

关键词： Ethidium bromide Spirulina platensis Oreochromis niloticus Liver Lipid peroxidation

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