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Natural ray-emitting radionuclides in Egyptian cement

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Nuclear Science and Techniques 2005年第6期16卷 376-380页

作者： a.m.el-arabi A.ABBADY A.H. el-KAmel A. NOSIER A. mOUSTAFA Physics Deptartment Faculty of Science Qena South Valley University Egypt Physics Deptartment Faculty of Science Assiut University Egypt Physics Deptartment Faculty of Science El-Azhar University Egypt

Samples of cement manufactured in Egypt and the raw materials have been analyzed usinggamma-spectroscopy, in order to determine the concentration of natural radionuclides and associated radiologicalhazard. The mean of specific activity due to radionuclides of 226 Ra, 232 Th and 40 K was found to be (20±4), (11± 2),(320±18) (gypsum), (41±8), (27±5), (410±27) (clay), (58±11), (18±3), (321±20) (iron ore) and (37.6±6), (11.8±3),(178.6±15) Bq?kg -1 (Portland cement), respectively. 40 K concentration could not be detected in slag, limestone, sul-phateresistant cement (S.R.C.), clinker and white cement, while the mean specific activities of 226 Ra and 232 Th are(239±16), (48.7±7); (31.5±5), (10±2); (47±7), (20±5); (23±5), (10.4±3) and (23±5), (11±3) Bq?kg -1 , respectively. Theactivities (concentrations) are in the same range as the data released in other countries. The calculated radiation haz-ardparameters for all the samples are still lower than the acceptable values in Egypt and other countries.

关键词： γ射线放射性核埃及伽马射线

Estimation of radiation hazard indices from natural radioactivity of some rocks

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Nuclear Science and Techniques 2006年第2期17卷 118-122页

作者： A.ABBADY N.K.AHmED a.m.el-arabi R.mICHel A.H.el-KAmel A.G.E.ABBADY Physics Department Faculty of Science Qena South Valley University Egypt Institute of the Radiation Protection and Radioecology Hannover University Germany Physics Department Faculty of Science Assiut University Egypt

Different samples of igneous and metamorphic rocks from Egypt and Germany have been considered to measure γ-ray activity concentrations due to naturally occurring, potentially hazardous radonuclides 226Ra, 232Th and 40K. The radiation hazard parameters including radiation equivalent activity, gamma-absorbed dose rate, and exter- nal and internal hazard indices have been estimated. The gamma-absorbed dose rates in air of rocks in Egypt range from 4.2 to 128.5 nGy·h-1 with a mean value of 55.3 nGy·h-1. For igneous and metamorphic rocks from Germany, the values of absorbed dose rates fluctuate from 5.1 to 148.6 nGy·h-1, with a mean value of 60.9 nGy·h-1. Generally, it is found that the radiation hazard indices in common igneous rocks are distinctly higher in acidic than in ultrabasic rocks. The results are discussed and compared with the corresponding published data.

关键词：自然放射性岩石变质岩环境放射学

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

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

Predicting peak ground acceleration using the Convmixer network

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Earthquake Science 2025年第2期38卷 126-135页

作者： mohammed, mona Saad, Omar m. Keshk, arabi Ahmed, Hatem m. National Research Institute of Astronomy and Geophysics (NRIAG) Cairo 11511 Egypt Division of Physical Science and Engineering King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Delta Technological University Menoufia 32684 Egypt Faculty of Computers and Information Menoufia University Menoufia 32512 Egypt

The level of ground shaking, as determined by the peak ground acceleration (PGA), can be used to analyze seismic hazard at a certain location and is crucial for constructing earthquake-resistant structures. Predicting the PGA immediately after an earthquake occurs allows for the issuing of a warning by an earthquake early warning system. In this study, we propose a deep learning model, Convmixer, to predict the PGA recorded by weak-motion velocity seismometers in Japan. We use 5-s three-component seismograms, from 2 s before until 3 s after the P-wave arrival time of the earthquake. Our dataset comprised more than 50,000 single-station waveforms recorded by 10 seismic stations in the K-NET, Kiki-NET, and Hi-Net networks between 2004 and 2023. The proposed Convmixer is a patch-based model that extracts global features from input seismic data and predicts the PGA of an earthquake by combining depth and pointwise convolutions. The proposed Convmixer network had a mean absolute error of 2.143 when applied to the test set and outperformed benchmark deep learning models. In addition, the proposed Convmixer demonstrated the ability to predict the PGA at the corresponding station site based on 1-second waveforms obtained immediately after the arrival time of the P-wave. © 2025 The Authors

关键词： deep learning (DL) earthquake early warning system (EEWS) peak ground acceleration (PGA)

Insights into transferal to fractal space modeling:delayed forced Helmholtz-Duffing oscillator with the non-perturbative approach

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Communications in Theoretical Physics 2025年第1期77卷 11-22页

作者： Yusry O el-Dib Department of mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

The damped Helmholtz-Duffing oscillator is a topic of great interest in many different fields of study due to its complex *** transitioning from conventional continuous differential equations to their fractal counterparts,one gains insights into the system's response under new mathematical *** paper presents a novel method for converting standard continuous differential equations into their fractal *** conversion occurs after the nonlinear system is transformed into its linear *** analyses show that there are several resonance sites in the fractal system,which differ from the one resonance point found in the continuous *** important finding is that the fractal system loses some of its stabilizing power when decaying behavior is transformed into a diffuse ***,a decrease in the fractal order in resonance settings shows a stabilizing impact,highlighting the dynamics'complexity inside fractal *** endeavor to convert to fractals is a revolutionary technique that is being employed for the first time.

关键词： nonlinear oscillations Helmholtz-Duffing oscillator forced with delay effect non-perturbative methodology stability outlines new perspectives on transferal to fractal space modeling

Water equivalence of some 3D dosimeters:a theoretical study based on the effective atomic number and effective fast neutron removal cross section

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Nuclear Science and Techniques 2017年第12期28卷 170-181页

作者： a.m.el-Khayatt Department of Physics College of Science Al Imam Mohammad Ibn Saud Islamic University (IMSIU) Reactor Physics Department NRC Atomic Energy Authority

Effective atomic numbers for photon energy absorption(ZPEA_(eff)) and their corresponding electron numbers (NPEA_(eff)), and effective macroscopic removal cross sections of fast neutrons(RR) were calculated for 27 different types of three-dimensional dosimeters, four types of phantom materials, and water. The values of ZPEA_(eff) and NPEA_(eff) were obtained using the direct method for energies ranging from 10 keV to 20 meV. Results are presented relative to water, for direct comparison over the range of examined energies. The effect of monomers that are used in polymer gel dosimeters on the water equivalence is discussed. The relation between Σ_R and hydrogen content was studied. micelle gel dosimeters are highly promising because our results demonstrate perfect matching between the effective atomic number, electron density number, and fast neutron attenuation coefficient of water.

关键词： 3D dosimeters Water equivalence Effective atomic number Photon energy absorption Removal cross section Fast neutrons

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

Optimal Distributed Dispatch of Smart multi-Agent Energy Hubs Based on Consensus Algorithm Considering Lossy Communication Network and Uncertainty

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CSEE Journal of Power and Energy Systems 2025年第1期11卷 352-364页

作者： Abdelfattah A.eladl magda I.el-Afifi magdi m.el-Saadawi Bishoy E.Sedhom electrical Engineering Department Faculty of EngineeringMansoura UniversityEl-MansouraEgypt

This paper proposes an IoT-Fog-Cloud distributed consensus algorithm for solving the energy hub(EH)dispatch problem with packet-dropping communication links and some of EH elements'*** generating and consumption unit in this algorithm is required to estimate total power generated,total load,and power *** node coordination is accomplished using a distributed *** a distributed approach wins in work sharing,enduring a single link failure,effective decision-making,quickest convergence,and autonomy for global power *** method works with all grid types in connected and islanded *** total operation cost and emissions while meeting total demand and system constraints are the most crucial contributions of this *** case studies are applied to explain performance and effectiveness of the proposed algorithm with different packet loss *** uncertainty,sensitivity of the system was *** show mismatch between generated and consumed power is improved by 100%in the electricity grid,99.94%in heating grid,and 99.91%in gas ***,total operating cost,total emissions,and emissions cost decreased by 8.6%,13.48%,and 18.73%,respectively.

关键词： Consensus algorithm CO_(2)emissions energy hubs multi-energy systems packet drops.