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Prospects delineation and evaluation using the CDP gathers characterization, onshore Nile Delta, Egypt

Petroleum Research 2019年第4期4卷 365-375页

作者： mohamed Hussein Ahmed S.Abu El-Ata mohamed g.El-Behiry Petroleum Engineering Department Faculty of EngineeringFuture University in EgyptEgypt geophysics Department Faculty of ScienceAin Shams UniversityEgypt geophysics Department Faculty of ScienceCairo UniversityEgypt

In the last decade, the seismic AVO analysis have become prominent in the direct hydrocarbons indicator(DHI), aimed at characterizing the fluid content or the lithology of a possible reservoir and reducing theexploration drilling risk. This research discuss the impact of studying the common depth point (CDP)gathers on Near, Mid and Far-offsets, to verify the credibility of the amplitude response in the prospectevaluation, through analyzing a case study of two exploratory wells;one has already penetrated a gasbearing sandstone as a reservoir and the other one is dry-sand, but drilled in two different prospects,using the amplitude versus offset (AVO) analysis, to understand the reservoir configuration and itsrelation to the different amplitude response. The results show, that the missing of the short-offset data isthe reason of the false anomaly encountered in the dry sand, due to some urban surface obstacles duringacquiring the seismic data in the field especially, the study area is located in El Mansoura city, which it isa highly cultivated flat terrain, with multiple channels and many large orchards on the edge of the river,and sugar cane and rice fields. Several lessons have been learned, which how to differentiate between thegas reservoirs and non-reservoirs, by understanding the relation between the Near and Far-offset traces,to reduce the amplitude anomalies to their right justification, where missing of Near-offset data led to apseudo-amplitude anomaly. The results led to a high success of exploration ratio as the positives vastlyoutweigh the negatives.

关键词： CDP gathers AVO analysis Seismic attributes Qawasim sands Near-offset

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ASSESSMENT OF TISSUE OPTICAL CLEARINg AS A FUNCTION OF gLUCOSE CONCENTRATION USINg OPTICAL COHERENCE TOMOgRAPHY

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Journal of Innovative Optical Health Sciences 2010年第3期3卷 169-176页

作者： NARENDRAN SUDHEENDRAN mohamed mohamed MOHAMAD g.gHOSN VALERY V.TUCHIN KIRILL V.LARIN Department of Electrical and Computer Engineering University of Houston N308 Engineering Building 1 HoustonTX 77204USA Department of Biomedical Engineering University of Houston 2028 SERC Building HoustonTX 77204USA Department of Medicine Baylor College of Medicine HoustonTX 77030USA Institute of Optics and Biophotonics Saratov State University Saratov 410012Russia Institute of Precise Mechanics and Control of RAS Saratov 410056 Russia

One of the major challenges in imaging biological tissues using optical techniques,such as optical coherence tomography(OCT),is the lack of light penetration due to highly turbid structures within the *** clearing techniques enable the biological samples to be more optically homogeneous,allowing for deeper penetration of light into the *** study investigates the effect of optical clearing utilizing various concentrations of glucose solution(10%,30%,and 50%)on porcine skin.A gold-plated mirror was imaged beneath the tissue and percentage clearing was determined by monitoring the change in reflected light intensity from the mirror over *** ratio of percentage clearing per tissue thickness for 10%,30% and 50% glucose was determined to be 4.7±1.6%mm^(−1)(n=6),10.6±2.0%mm^(−1)(n=7)and 21.8±2.2%mm^(−1)(n=5),*** was concluded that while higher glucose concentration has the highest optical clearing effect,a suitable concentration should be chosen for the purpose of clearing,considering the osmotic stress on the tissue sample.

关键词： glucose porcine skin percent clearing scattering coefficient optical coherence tomography

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growth of gas bubbles in the biotissues with convective acceleration

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International Journal of Biomathematics 2014年第6期7卷 223-238页

作者： S. A. Mohammadein K. g. mohamed Department of Mathematics Faculty of Science Tanta University Tanta Egypt Department of Mathematics Faculty of Science Benha University Benha Egypt

This paper presents formulae and explanation about the growth of a convective gas bubble in the blood and other tissues of divers who surface too quickly, concentration distribution around the growing bubble is also presented. The formulae are valid all over the growth stages, i.e. under variable ambient pressure while the diver is ascending, and under constant ambient pressure at diving stops or at sea level. The mathematical model is solved analytically by using the method of combined variables. The growth process is affected by tissue diffusivity, concentration constant and the initial void fraction, which is the dominant parameter. Results show that, the time of the complete growth, in the convective growth model, is shorter than those earlier presented by Mohammadein and mohamed [Concentration distribution around a growing gas bubble in tissue, Math. Biosci. 225（1）（2010） 11-17] and Srinivasan et al. [Mathematical models of diffusion- limited gas bubble dynamics in tissue, J. Appl. Physiol. 86 （1999） 732-741] for the growth of a stationary gas bubble, this explains the effect of bubble motion on consuming the oversaturated dissolved gas from the tissue into growing bubble which leads to increment in the growth rate to be more than those presented in the previous stationary models.

关键词： gas bubble concentration distribution convective growth method of com- bined variables.

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Summary of the current guidelines for managing iatrogenic colorectal perforations and the evolving role of endoluminal vacuum therapy

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World Journal of Clinical Cases 2025年第6期13卷 1-8页

作者： Ahmed Tawheed Ibrahim Halil Bahcecioglu Mehmet Yalniz Mubin Ozercan Ali Cagri Oral mohamed El-Kassas Department of Endemic Medicine Faculty of MedicineHelwan UniversityCairo 11795Egypt Department of gastroenterology Firat UniversityElazig 23119Türkiye Liver Disease Research Center College of MedicineKing Saud UniversityRiyadh 7805Saudi Arabia

Colonoscopy represents a safe procedure that is widely used in medical practice either to diagnose or treat various gastrointestinal *** the last few years,the incidence rate of perforations in colonoscopic procedures has increased,especially in therapeutic *** recent advancements in endoscopic techniques and gastrointestinal tumoral resection procedures such as endoscopic mucosal resection,endoscopic full-thickness resection,and endoscopic submucosal dissection(ESD)could be a risk factor for this increased *** incidence rate of mortality of serious colonoscopic perforations is 7.1%.The management plan for these perforations starts with conservative treatment in mild cases,endoscopic closure,and surgical management in severe ***,endoluminal vacuum therapy was found to be effective in the management of colorectal perforations and this has been reported in multiple case *** editorial provides an overview of the current guidelines for the management of iatrogenic colorectal *** insights are from the perspectives of endoscopists and *** also present a management algorithm based on the guidelines of the European Society of gastrointestinal Endoscopy,the American gastroenterological Association,and the World Society of Emergency *** also discussed in brief the use of endoluminal vacuum therapy in colorectal perforations.

关键词： Colon Rectum Iatrogenic colonic perforation Colonoscopy guidelines Endovacuum Endolumical vacuum therapy Endoscopic management

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Dynamic Interaction Analysis of Coupled Axial-Torsional-Lateral Mechanical Vibrations in Rotary Drilling Systems

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Structural Durability & Health Monitoring 2025年第1期19卷 77-103页

作者： Sabrina Meddah Sid Ahmed Tadjer Abdelhakim Idir Kong Fah Tee mohamed Zinelabidine Doghmane Madjid Kidouche Applied Automation Laboratory Faculty of Hydrocarbons and ChemistryUniversity of BoumerdesBoumerdes35000Algeria Institute of Electrical and Electronic Engineering(IgEE) University of BoumerdesBoumerdes35000Algeria Laboratory of the Electrification of Industrial Enterprises University of BoumerdesBoumerdes35000Algeria Electrical Engineering Department Mohamed Boudiaf University of M’silaM’sila28000Algeria Department of Civil and Environmental Engineering King Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Construction and Building Materials King Fahd University of Petroleum&Minerals(KFUPM)Dhahran31261Saudi Arabia

Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and *** achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is *** study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling *** study speciﬁcally investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency *** events not only hinder the efﬁciency of drilling but also lead to exhaustion and harm to the system’s components since they are difﬁcult to be detected and controlled in real *** study investigates the dynamic interactions of these vibrations,speciﬁcally in their high-frequency modes,usingﬁeld data obtained from measurement while ***ﬁndings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem *** obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control ***,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect ***,by exploiting theseﬁndings,the assessment of structural resilience in rotary drilling systems can be ***,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efﬁciency of rotary drilling systems in the petroleum industry.

关键词： Rotary drilling systems mechanical vibrations structural durability dynamic interaction analysis ﬁeld data analysis

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Projective Hilbert modules and sequential approximations

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Science China Mathematics 2025年第1期 137-168页

作者： Lawrence g.Brown Huaxin Lin Department of Mathematics Purdue University Department of Mathematics East China Normal University Department of Mathematics University of Oregon Shanghai Institute for Mathematics and Interdisciplinary Sciences

We show that when A is a separable C*-algebra,every countably generated Hilbert A-module is projective（with bounded module maps as morphisms）.We also study the approximate extensions of bounded module *** the case where A is a σ-unital simple C*-algebra with strict comparison,and every strictly positive lower semicontinuous affine function on quasitraces can be realized as the rank of an element in the Cuntz semigroup,we show that the Cuntz semigroup is equivalent to unitarily equivalent classes of countably generated Hilbert A-modules if and only if A has stable rank one.

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EJUSTCO:Monte Carlo radiation transport code hybrid with ANN model for gamma-ray shielding simulation

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Nuclear Science and Techniques 2023年第9期34卷 155-176页

作者： Joseph Konadu Boahen Ahmed S.g.Khalil Mohsen A.Hassan Samir A.Elsagheer mohamed Materials Science and Engineering Department School of Innovative Design EngineeringEgypt-Japan University of Science and Technology(E-JUST)179New Borg El-Arab CityEgypt Physics Department Environmental and Smart Technology GroupFaculty of ScienceFayoum UniversityFayoum 63514Egypt Faculty of Engineering Aswan UniversityAswanEgypt

gamma ray shielding is essential to ensure the safety of personnel and equipment in facilities and environments where radiation *** Monte Carlo technique is vital for analyzing the gamma-ray shielding capabilities of *** this study,a simple Monte Carlo code,EJUSTCO,is developed to cd simulate gamma radiation transport in shielding materials for academic *** code considers the photoelectric effect,Compton(incoherent)scattering,pair production,and photon annihilation as the dominant interaction mechanisms in the gamma radiation shielding *** reduction techniques,such as the Russian roulette,survival weighting,and exponential transformation,are incorporated into the code to improve computational *** the exponential transformation parameter typically requires trial and error as well as ***,a deep learning neural network is proposed as a viable method for predicting this parameter for the first *** model achieves an MSE of 0.00076752 and an R-value of *** exposure buildup factors and radiation dose rates due to the passage of gamma radiation with different source energies and varying thicknesses of lead,water,iron,concrete,and aluminum in single-,double-,and triple-layer material systems are validated by comparing the results with those of MCNP,ESg,ANS-6.4.3,MCBLD,MONTEREY MARK(M),PENELOPE,and *** errors of 5.6%,2.75%,and 10%are achieved for the exposure buildup factor in single-,double-,and triple-layer materials,respectively.A significant parameter that is not considered in similar studies is the gamma ray *** the EJUSTCO code,the total number and energy albedos have been *** results are compared with those of MCNP,FOTELP,and *** general,the EJUSTCO-developed code can be employed to assess the performance of radiation shielding materials because the validation results are consistent with theoretical,experimental,and literary results.

关键词： Monte Carlo gamma rays Shielding Artificial neural network Simulation

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Luminescent characterization of rare earth Dy^(3+) ion doped TiO_2 prepared by simple chemical co-precipitation method

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Journal of Rare Earths 2019年第1期37卷 24-31,M0003页

作者： mohamed Zikriya Y.F.Nadaf P.Vijai Bharathy C.g.Renuka Department of Physics Bangalore University Department of Physics and Research Center Maharani's Science College for Women Department of Physics CBM College

Pure and rare-earth ion (Dy^(3+)) doped TiO_2 nanomaterials were prepared through a chemical coprecipitation method. The chemical composition, micro structure and optical properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy and photo luminescence (PL). XPS analysis reveals that Dy^(3+)ions are preferentially occupied in the TiO_2 crystallite lattices. Both the XRD and TEM analyses confirm that both the pure and Dy doped TiO_2 are in pure anatase phase and in nano size range, respectively. Also it is found that the maximum solubility limit for Dy^(3+) ions is found to be 0.4%in TiO_2 matrix, above which it occupies interstitials and/or crystallite surface of TiO_2 nanocrystals. From the UV-Vis spectroscopy studies it is found that Dy doping induces blue shift in TiO_2. From the PL analysis it is found that doping Dy^(3+) improves the luminescence behavior in comparison with the pure TiO_2 ***, doping very low concentrations of Dy^(3+) greatly alters the structural morphology and directly increases the luminescence behavior of TiO_2 suitable for advanced optoelectronic applications.

关键词： Rare earth ions TiO2 Dy^3+ion Microstructure Photoluminescence

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A probabilistic model for sediment entrainment:The role of bed irregularity

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International Journal of Sediment Research 2017年第2期32卷 137-148页

作者： mohamed Elhakeem A.N.Thanos Papanicolaou Achilleas g.Tsakiris Abu Dhabi University University of Tennessee Civil and Environmental Engineering University of Tennessee

A generalized probabilistic model is developed in this study to predict sediment entrainment under the incipient motion,rolling,and pickup modes.A novelty of the proposed model is that it incorporates in its formulation the probability density function of the bed shear stress,instead of the near-bed velocity fluctuations,to account for the effects of both flow turbulence and bed surface irregularity on sediment *** proposed model incorporates in its formulation the collective effects of three parameters describing bed surface irregularity,namely the relative roughness,the volumetric fraction and relative position of sediment particles within the active *** key feature of the model is that it provides a criterion for estimating the lift and drag coefficients jointly based on the recognition that lift and drag forces acting on sediment particles are interdependent and vary with particle protrusion and packing *** model was validated using laboratory data of both fine and coarse sediment and was compared with previously published *** study results show that all the examined models perform adequately for the fine sediment data,where the sediment particles have more uniform gradation and relative roughness is not a *** proposed model was particularly suited for the coarse sediment data,where the increased bed irregularity was captured by the new parameters introduced in the model *** a result,the proposed model yielded smaller prediction errors and physically acceptable values for the lift coefficient compared to the other models in case of the coarse sediment data.

关键词： Sediment entrainment Probabilistic models Bed surface irregularity Active layer relative roughness Packing density Volumetric fraction of sediment

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Structural Characterization and Antioxidant Activity of Lignin Extracted from Ficus Carica L.

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Journal of Renewable Materials 2019年第4期7卷 345-354页

作者： Ibtissem Moussa Ramzi Khiari Ali Moussa gérard Mortha mohamed Farouk Mhenni University of Monastir Faculty of SciencesUR13 ES 63-Research Unity of Applied Chemistry&EnvironmentAvenue of the environment5019 MonastirTunisia University of Monastir National Engineering School of MonastirStreet of Ibn El Jazzar5000 MonastirTunisia Higher Institute of Technological Studies of Ksar-Hellal Department of Textile-TunisiaAvenue of Hadj Ali Soua.5070 Ksar-HellalTunisia University of grenoble Alpes CNRSGrenoble INPLGP2F-38000 GrenobleFrance

The most abundant phenolic biopolymer in the biosphere is the *** phenolic biopolymer commonly exists in combination with polysaccharides and other cell wall *** this study,the solvent system dioxane-water is used to extract lignin,which is considered as unaltered native *** dioxane lignin extracted from fig stems was characterized regarding to its structural feature,quantification of its functional groups,molecular weight,and evaluation of its thermal *** and molecular weight distribution of the studied lignin indicated that isolated lignin contained a low amount of sugar(c.a.19%)and had a high weight-average molecular weight(10068 ***-1).Lignin sample had approximately the same amounts of guaiacyl(g)and p-hydroxyphenyl(H)units with relatively fewer syringyl(S)*** isolated lignin revealed good antioxidant ***,it proved to have a high potential of application in new antioxidants formulations.

关键词： Ficus Carica L. lignin organosolv molecular weight NMR spectroscopy antioxidant activity

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