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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

Anti-wear properties evaluation of frictional sliding interfaces in automobile engines lubricated by copper/graphene nanolubricants

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Friction 2020年第5期8卷 905-916页

作者： mohamed Kamal ahmed ali Xianjun HOU mohamed AAABDELKAREEM Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Automotive and Tractors Engineering Department Faculty of EngineeringMinia UniversityEl-Minia 61111Egypt Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan 430070China

Owing to the significance of improving fuel economy, reducing emissions, and extending the durability of engine components, this study focused on the tribological performance of nano-additives. In this study, copper (Cu) and graphene (Gr) nanomaterials were dispersed in a fully formulated engine oil (5W-30) with different concentrations. The tribological trials were investigated under various speeds and loads, utilizing a reciprocating tribometer to mimic the ring/liner interfaces in the engine. The frictional surface morphologies were com-prehensively analyzed using electron probe X-ray microanalysis (EPMA), field emission scanning electron microscopy (FESEM), energy dispersive spectrometer (EDS), and three dimensional (3D) surface profilometry to explore the mechanisms responsible for improving the tribological performance of the frictional sliding parts in the engine. The tribological test results illustrated that lubrication by nano-additives reduced the wear rate (WR) and friction coefficient (COF) by 25%–30% and 26.5%–32.6%, respectively, as compared with 5W-30. The results showed that this is a promising approach for increasing the durability and lifespan of frictional sliding components and fuel economy in automobile engines.

关键词： engine tribology nanomaterial nanolubricant friction wear tribofilm

Evaluation of implanted perforated lacrimal punctal plugs using anterior segment optical coherence tomography

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Eye and Vision 2021年第1期8卷 366-373页

作者： Raafat Mohyeldeen abdelrahman Abdallah ahmed mohamed Kamal Elshafei Heba Radi AttaAllah Ophthalmology Department Minia UniversityEl‑MiniaEgypt Ophthalmology Department Minia University HospitalEl‑MiniaEgypt

Purpose:Evaluation of the patency and position of perforated lacrimal punctal plugs implanted for treating punctal stenosis together with quantitative assessment of the precorneal tear film using anterior segment optical coherence tomography(AS-OCT).Methods:In a prospective study,the lower punctum of 54 eyes of 29 patients implanted with perforated punctal plugs were examined using AS-OCT during the early postoperative *** tear meniscus height(TMH)and tear meniscus area(TMA)were ***,the patency of the plug,its position,TMH and TMA were evaluated,and the results were correlated with postoperative *** scale was used for epiphora ***:Using AS-OCT,48(88.9%)plugs were found in proper position while 6(11.1%)were *** lumen of the plugs was completely patent in 47(87%)plugs,partially obstructed in 2(3.7%)plugs and completely occluded in 5(9.2%)*** was a statistically significant postoperative decrease of TMH and TMA(P<0.001)and postoperative epiphora Munk score(P<0.001).Conclusion:AS-OCT is a valuable,reliable,and noninvasive investigative tool that can detect the proper positioning,patency,and contents of the implanted perforated lacrimal punctal plugs in addition to measurement of TMH and TMA.

关键词： AS-OCT Perforated plugs Plugs

HDR Image Reconstruction from a Single LDR Image Using Deep CNN

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HDR Image Reconstruction from a Single LDR Image Using Deep ...

作者： mohamed abdelrahman ahmed Dafaallah 山东大学

学位级别：硕士

高动态范围（HDR）成像是图像处理和计算机图形方面的快速增长领域。这是一种可以代表各种现实世界亮度的摄影技术。相比之下,传统成像也称为低动态范围（LDR）成像不能代表真实世界的强度和颜色,因为大多数数码相机都可以在自然场景中... 详细信息

高动态范围（HDR）成像是图像处理和计算机图形方面的快速增长领域。这是一种可以代表各种现实世界亮度的摄影技术。相比之下,传统成像也称为低动态范围（LDR）成像不能代表真实世界的强度和颜色,因为大多数数码相机都可以在自然场景中捕获有限的光强度范围。HDR成像克服了这种限制,允许捕获和传递可以与人类视觉系统的动态范围相匹配的信息。此HDR信息可用于各种应用程序,例如音调映射,基于图像的照明,HDR显示器,计算机视觉和其他后处理操作。HDR成像已经有了很多开发,但是尽管如此,就内容而言,LDR成像仍然是当今的标准。要在不同的HDR应用程序中使用此内容,需要将LDR内容转换为HDR,并将由于饱和或量化而丢失的信息需要恢复。本文工作的目的是开发深神网络,目的是从单个暴露LDR图像中重建HDR图像。我们利用卷积神经网络能力来克服先前作品的局限性,并处理重建HDR内容（例如暴露面积过度,暴露面积不足的区域,量化和线性化）时遇到的问题。在这项工作中,我们提出了两个用于HDR图像重建的新型CNN。使用深度学习的最新进展,在大型HDR图像数据集上对网络进行了培训。第一种方法在卷积自动编码网络上使用深度监督技术。除了输出层的总体损耗函数外,深度监督还增加了每个隐藏层的伴侣损失功能。这有助于网络轻松恢复较低分辨率的结构,并以更高分辨率恢复纹理。第二种方法采用了卷积自动编码器,该自动编码器使用剩余学习技术来加速培训,注意机制以增强有用的功能和上下文注意模块,以帮助恢复在暴露区域中丢失的信息。公共HDR数据集的广泛定量和定性实验表明,与现有方法相比,我们提出的方法有效地重建视觉上令人愉悦的HDR图像并显示出更好的性能的能力。

关键词：深度学习卷积神经网络计算摄影 HDR成像单幅图像HDR重建

A Deep Learning Ensemble Method for Forecasting Daily Crude Oil Price Based on Snapshot Ensemble of Transformer Model

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Computer Systems Science & Engineering 2023年第7期46卷 929-950页

作者： ahmed Fathalla Zakaria Alameer mohamed Abbas ahmed ali Department of Mathematics Faculty of ScienceSuez Canal UniversityIsmailia41522Egypt Mining and Petroleum Department Faculty of EngineeringAl-Azhar UniversityQenaEgypt School of Computer Science and Technology Central South UniversityChangshaHunanChina College of Computer Engineering and Sciences Prince Sattam Bin Abdulaziz UniversityAl-Kharj11942Saudi Arabia Higher Future Institute for Specialized Technological Studies Cairo3044Egypt

The oil industries are an important part of a country’s *** crude oil’s price is influenced by a wide range of ***,how accurately can countries predict its behavior and what predictors to employ are two main *** this view,we propose utilizing deep learning and ensemble learning techniques to boost crude oil’s price forecasting *** suggested method is based on a deep learning snapshot ensemble method of the Transformer *** examine the superiority of the proposed model,this paper compares the proposed deep learning ensemble model against different machine learning and statistical models for daily Organization of the Petroleum Exporting Countries(OPEC)oil price *** results demonstrated the outperformance of the proposed method over statistical and machine learning *** precisely,the proposed snapshot ensemble of Transformer method achieved relative improvement in the forecasting performance compared to autoregressive integrated moving average ARIMA(1,1,1),ARIMA(0,1,1),autoregressive moving average(ARMA)(0,1),vector autoregression(VAR),random walk(RW),support vector machine(SVM),and random forests(RF)models by 99.94%,99.62%,99.87%,99.65%,7.55%,98.38%,and 99.35%,respectively,according to mean square error metric.

关键词： Deep learning ensemble learning transformer model crude oil price

Techno-economic analysis to develop the first wind farm in the Egyptian western desert at Elkharga Oasis

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Clean Energy 2022年第1期6卷 211-225页

作者： mohamed A.abdelrahman Radwan H.Abdel-Hamid Maged ahmed Abo Adma mohamed Daowd Electrical Power and Machines Department Faculty of EngineeringHelwan UniversityCairoEgypt

During the past few years,Egypt has increased the share of electricity generation from renewable energy sources to achieve the renewable-energy *** Egyptian Ministry of Electricity and Renewable Energy has set an ambitious target to increase the share of renewable energy among the total energy mix to be 20%by 2022 and 42%by *** target will be achieved using several approved policies such as feed-in tariffs,build-own-operate and independent power producers under a merchant *** paper presents a full analysis of wind-potential characteristics at Elkharga Oasis in Egypt based on an actual wind-measurement campaign taken by a met mast at two height levels of 10 and 25 m,*** measurements show an average annual wind speed of 5.72 m/s at 10-m height and 6.53 m/s at>25-m *** estimated wind speed,however,is 8.38 m/s at 120 m,which is technically convenient to generate electricity from wind *** this paper,the wind potential in the area is assessed using the statistical method of the Weibull probability density *** different methods to estimate the Weibull distribution parameters are presented and the relevant accuracy is verified based on the root mean square error.A techno-economic assessment and selection of the optimal wind-turbine size with ideal micro-sitings are performed using the software package *** cases of study for three typical wind-turbine models with various rotor diameters,power capacity,layout configuration and annual yield are assessed at the *** selection of the most convenient wind turbine is determined based on the IEC 61400 standard criteria and the turbine that produces the lowest levelized cost of electricity.

关键词： wind energy wind-resource assessment Weibull distribution windPRO levelized cost of electricity

The Utilization of Eucalyptus Oil for Reducing Methane Production in Ruminants under in Vitro Conditions

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The Utilization of Eucalyptus Oil for Reducing Methane Produ...

作者： Safwat mohamed abdelrahman ahmed Attia 吉林农业大学

学位级别：硕士

畜牧业产生的甲烷是引起全球变暖的主要因素。地球气候变暖成为全球重要问题之一。本研究中在体外条件下研究不同浓度的桉叶油对瘤胃中生产甲烷的抑制作用。试验设计为:不同精粗比的饲粮,分别为70:30和60:40。饲粮干物质中桉叶油的浓度... 详细信息

畜牧业产生的甲烷是引起全球变暖的主要因素。地球气候变暖成为全球重要问题之一。本研究中在体外条件下研究不同浓度的桉叶油对瘤胃中生产甲烷的抑制作用。试验设计为:不同精粗比的饲粮,分别为70:30和60:40。饲粮干物质中桉叶油的浓度分别为0 mL/kg、2 mL/kg、4 mL/kg、6 mL/kg、8 mL/kg和10 mL/kg。试验采用的瘤胃原液从两只健康瘘管绵羊获取,分别在3 h、6 h、9 h、12 h、24 h、36 h、48 h和72 h,检测气压(GP)、甲烷产量(CH4)。发酵(72 h)结束后,检测挥发性脂肪酸(VFA)、氨态氮(NH3)、干物质降解率(DMD)及有机物降解率(OMD)、pH值和原生动物数等。结果表明,不同浓度的桉叶油处理条件下,甲烷产量有所降低(P<0.05)。在精粗比30:70的处理中,2 mL/kg组的甲烷产量较对照组减少32%,10 mL/kg组的甲烷产量较对照组减少38%。在精粗比60:40的处理中,2 mL/kg组的甲烷产量较对照组减少42%,10 mL/kg组的甲烷产量较0 mL/kg组减少46%。在所有精粗比处理中,通过提高桉叶油的浓度,与0 mL/kg组相比,原虫数量显著下降(P<0.05)。NH3浓度较0 mL/kg组下降,在精粗比为60:40组中不显著,在70:30中显著(P<0.05)。在所有精粗比处理中,随着桉叶油浓度的提高,A/P值、DMD和OMD都显著下降(P<0.05)。除了精粗比70:30处理中的10 mL/kg组,其他各组的pH值没有显著差异。综上,2 mL/kg组为效率最高组。该浓度的桉叶油降低甲烷气体为最佳浓度。同时成本也是最低的。

关键词：污染瘤胃桉叶油甲烷反刍动物

Geology and Mineral Chemistry of Uranium-and Thorium-bearing Minerals in Rare-Metal(NYF)Pegmatites of Um Solimate,South Eastern Desert,Egypt

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Acta Geologica Sinica(English Edition) 2021年第5期95卷 1568-1582页

作者： mohamed A.ali ahmed E.ABDEL GAWAD mohamed M.GHONEIM Nuclear Materials Authority 530 El-MaadiCairoEgypt

The garnet muscovite granitic pegmatite of Um Solimate,in southern Egypt,represents a promising asset for strategic and economic metals,especially Bi-Ni-Ag-Nb-Ta as well as U and *** ore bodies occur as large masses,pockets and/or veins of very coarse-grained pegmatites,which consist mainly of K-feldspar,quartz and albite with subordinate muscovite,garnet,and *** data revealed that e U-and e Th-contents of the pegmatites reach up to 39 ppm and 82 ppm,*** studied pegmatites are enriched in primary U and Th minerals(uraninite,coffinite,thorianite and uranothorite)as well as Hf-rich zircon and monazite,which give rise to anomalous radioactive ***-tantalium-bearing minerals(***,microlite and uranopyrochlore),xenotime,barite,galena,fluorite,and apatite are ubiquitous,and,consequently,the studied pegmatites belong tothe Niobium-Yttrium-Fluorine-type(NYF)*** noble metal mineralization includes argentite(Ag_(2)S),native Ni and Bi as well as bismite and *** addition,beryl and tourmaline are observed in pegmatites near the contact with metasediments and ultramafic *** observed compositional variations of Ta/(Ta+Nb)and Mn/(Mn+Fe)ratios in columbite(0.08-0.45 and 0.11-0.57,respectively)and Hf contents in zircon(3.54-6.46 wt%)may reflectan extreme degree of magmatic fractionation leading to formation of the pegmatite orebody.

关键词： radioactivity rare-metal mineralization pegmatites U/Th-bearing minerals Um Solimate Egypt

Impact of composition ratio on the structure and optical properties of(1-x)MnFe_(2)O_4/(x)ZnMn_(2)O_4 nanocomposite

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Chinese Physics B 2022年第7期31卷 481-489页

作者： Zein K.Heiba mohamed Bakr mohamed ali A.Alkathiri Sameh I.ahmed A A Alhazime Department of Physics Faculty of ScienceAin shams UniversityCairo 11566Egypt Physics Department Faculty of ScienceTaibah UniversityAl-Madina al MunawarahSaudi Arabia Depatment of Physics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

(1-x)MnFe_(2)O_(4)(MFO)/xZnMn_(2)O_(4)(ZMO)(x=0,0.2,0.5,0.8,and 1.0)nanocomposite samples were prepared using co-precipitation *** phase percentage,cell parameters,and crystallite size of MFO and ZMO phases in each nanocomposite sample were calculated using Rietveld refinement *** x-ray diffraction(XRD)analysis and Fourier-transform infrared spectroscopy techniques established the variation in the lattice parameters of each phase are due to permutation of all cations among the octahedral and tetrahedral sites of MFO and *** different oxidation states of different ions in all samples were determined using x-ray photoelectron spectroscopy(XPS)*** variation in absorbance of the nanocomposite samples with composition parameter(x)is dependent on the wavelength *** optical bandgap of the nanocomposite samples is decreased as the content of ZMO phase *** effect of alloying on the refractive index,extinction coefficient,dielectric constant,optical conductivity,and the nonlinear optical behaviors of all samples were studied in *** nanocomposite sample x=0.5 disclosed upgraded optical parameters with the highest refractive index,optical conductivity,and PL intensity,which nominate it to be functional in various application fields.

关键词： MFO and ZMO composite XPS structure optical