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Using nanotechnology to prevent fines migration while production

Petroleum 2021年第2期7卷 168-177页

作者： Mohamed Mansour Mohamed Eleraki Ahmed noah El-Abbas Moustafa Faculty of Science Zagazig UniversityEgypt Egyptian Petroleum Research Institute(EPRI) Egypt The British University Egypt

Formation damage due to fines migration is a major reason for well productivity decline for oil and gas *** fines are small enough to pass through pore throats causing pore plugging and permeability *** factors affect fines migration such as flow rate,salinity,pH value,reservoir temperature and oil polarity,as well as changes in chemical environment induced by Enhanced Oil Recovery(EOR)*** paper focuses on the effect of flow rates on fines detachment from the grain surfaces,which causing permeability *** the fluid inside the reservoir moves towards the wellbore,the fluid velocity increases,when the fluid reaches the critical flow rate these fines can be picked up into the *** fines captured by thinner pore throats causing pore plugging and permeability *** concentrations of nanoparticles were used to fix these fines on their sources and prevent their mobilization at high flow *** unique technique used in this study is changing the potential surfaces between fines and grain surfaces to prevent fines movement above the critical flow ***_(2)and MgO NPs used in this study can be adsorbed on the pore surfaces and reduce the repulsion forces between fines and pore ***_(2) and MgO nanoparticles at different concentrations(0.25,0.50 and 0.75 g/L)were used on treating the Abu-Rawash sandstone reservoir using Formation Damage System Cell *** experimental studies showed that using MgO NPs would prevent fines detachment from the pore surfaces and decrease the reduction of permeability at high flow rates more than SiO_(2) *** optimum concentration of MgO NPs was at 0.5 g/L as the permeability remediation at this concentration reaches to 64.83%.

关键词： Formation damage Fines migration Nanoparticles Zeta potential Permeability reduction Fluid flow rate

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The formation of orthogonal joint systems and cuboidal blocks:New insights gained from flat-lying limestone beds in the region of Havre-Saint-Pierre(Quebec,Canada)

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第12期15卷 3079-3093页

作者： Shaocheng Ji Yvéric Rousseau Denis Marcotte noah John Phillips Département des Génies Civil Géologique et des MinesÉcole Polytechnique de MontréalMontréalQuébecH3C 3A7Canada Department of Geology Lakehead UniversityThunder BayOntarioP7B 5E1Canada

Vertical orthogonal joints are a common feature in shallow crustal *** are several competing theories for their formation despite the *** examined the exceptional exposures of orthogonal joints in flat-lying Ordovician limestone beds from the Havre-Saint-Pierre Region in Quebec,Canada(north shore of Saint-Lawrence River)to test conceptual models of joint formation in a natural *** the region,the spacing of cross-joints is consistently larger than the spacing of systematic joints by a factor of 1.5 *** joint-spacing-to-bed-thickness ratios(s/t)are much larger in these beds(s/t=4.3 for systematic joints,and 6.4 for cross-joints)than those in higher strained strata along the south shore of the Saint-Lawrence River(s/t=1),highlighting the effect of tectonic strain in decreasing fracture spacing and block *** high values of s/t indicate that cross-joint formation was unlikely caused by a switch from compression to tension once a critical s/t ratio for systematic joints was reached(as hypothesized in previous studies).We proposed a new model for the formation of orthogonal joint systems where the principal stress axes locally switch during the formation of systematic *** presence of ladder-shaped orthogonal joints suggests a state of effective stress withσ_(1)^(∗)≫0>σ_(2)^(∗)>σ_(3)^(∗)and whereσ_(2)^(∗)-σ_(3)^(∗)is within the range of fracture strength variability at the time of *** research provides a new mechanical model for the formation of orthogonal joint systems and cuboidal blocks.

关键词： Plato's cuboids Orthogonal joints Fracture spacing Limestone Layered rock mechanics Appalachian geology

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On Polynomial Maximum EntropyMethod for ClassicalMoment Problem

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Advances in Applied Mathematics and Mechanics 2016年第1期8卷 117-127页

作者： Jiu Ding noah H.Rhee Chenhua Zhang Department of Mathematics The University of Southern MississippiHattiesburgMS 39406-5045USA Department ofMathematics and Statistics University ofMissouri–Kansas CityKansas CityMO 64110-2499USA

The maximum entropy method for the Hausdorff moment problem suffers from ill conditioning as it uses monomial basis{1,x,x2,···,xn}.Themaximum entropy method for the Chebyshev moment probelm was studied to overcome this drawback in[4].In this paper we review and modify the maximum entropy method for the Hausdorff and Chebyshev moment problems studied in[4]and present the maximum entropy method for the Legendre moment *** also give the algorithms of converting the Hausdorff moments into the Chebyshev and Lengendre moments,respectively,and utilizing the corresponding maximum entropy method.

关键词： Classical moment problem monomials Chebyshev polynomials Legendre polynomials

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Fault Diagnosis of Roller Bearing Using Deep Learning

Fault Diagnosis of Roller Bearing Using Deep Learning

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作者： RONO noah KIPYEGO 湖南大学

学位级别：硕士

滚动轴承故障诊断在机械操作中起着关键作用。比如,滚动轴承故障诊断在确保工作环境的安全性、防止机械故障、消除与滚动轴承部件故障相关的其他风险是非常重要的,最重要的是帮助工程师和其他部门做出决策以及时预防性维护。因此,为了... 详细信息

滚动轴承故障诊断在机械操作中起着关键作用。比如,滚动轴承故障诊断在确保工作环境的安全性、防止机械故障、消除与滚动轴承部件故障相关的其他风险是非常重要的,最重要的是帮助工程师和其他部门做出决策以及时预防性维护。因此,为了提高滚动轴承故障诊断技术的可靠性,迫切需要在滚动轴承故障诊断领域进行更多的研究。故障诊断过程可归纳为四个阶段:振动信号采集阶段,从信号中提取重要特征的特征提取阶段,降维阶段将高维特征降到低维,最后分类阶段来诊断部件的状况。滚动轴承故障诊断的分特征提取可以分为两类:统计特征和深度学习特征。深度学习方法即堆叠自动编码器和堆叠去噪自动编码器有很多优点,例如自动特征提取和高性能,因此使它们在选择合适的滚动轴承故障诊断方法时更为优选。在本论文工作中,集合经验模式分解(EEMD)被用于提取统计模型中的特征,浅层学习,然后被馈送到奇异值分解(SVD)以进行特征的降维,最后支持向量机分类器(SVM)用于轴承的状态识别。在深度学习的情况下,客观地使用简单自编码(AE),堆叠自编码(SAE)和堆叠去噪自编码(SDAE)来诊断故障。这些深度学习方法纯粹是无监督的。重要的是,这些方法不需要预处理输入数据,而是将原始数据直接馈入模型,然后进行数据训练,在堆叠去噪自动编码器的情况下添加噪声,然后训练每层自动编码器,最后引入支持向量机进行分类处理。然后在性能,稳定性等方面比较统计模型和深度学习模型的结果。

关键词：故障诊断滚动轴承 AE SAE SDAE 深度学习降维 EEMD SVD

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Superconductivity in antiperovskites

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npj Computational Materials 2022年第1期8卷 1424-1433页

作者： noah Hoffmann Tiago F.T.Cerqueira Jonathan Schmidt Miguel A.L.Marques Institut für Physik Martin-Luther-Universität Halle-WittenbergD-06099HalleGermany CFisUC Department of PhysicsUniversity of CoimbraRua Larga3004-516CoimbraPortugal

We present a comprehensive theoretical study of conventional superconductivity in cubic antiperovskites materials with composition XYZ_(3) where X and Z are metals,and Y is H,B,C,N,O,and *** starting point are electron–phonon calculations for 397 materials performed with density-functional perturbation *** 43%of the materials are dynamically unstable,we discovered 16 compounds close to thermodynamic stability and with T_(c) higher than 5 *** these results to train interpretable machine-learning models,leads us to predict a further 57(thermodynamically unstable)materials with superconducting transition temperatures above 5 K,reaching a maximum of 17.8 K for ***,the models give us an understanding of the mechanism of superconductivity in *** combination of traditional approaches with interpretable machine learning turns out to be a very efficient methodology to study and systematize whole classes of materials and is easily extendable to other families of compounds or physical properties.

关键词： properties theory perovskite

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Ca2+ sparks as a plastic signal for skeletal muscle health,aging,and dystrophy

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Acta Pharmacologica Sinica 2006年第7期27卷 791-798页

作者： noah WEISLEDER 675 Hoes Lane Department of Physiology and Biophysics UMDNJ-Robert Wood Johnson Medical School NJ 08854 Piscataway USA

Ca2+sparks are the elementary units of intracellular Ca2+signaling in striated musclecells revealed as localized Ca2+release events from sarcoplasmic reticulum(SR)byconfocal *** Ca2+sparks are well defined in cardiac muscle,therehas been a general belief that these localized Ca2+release events are rare in intactadult mammalian skeletal *** laboratories determined that Ca2+sparksin mammalian skeletal muscle could only be observed in large numbers when thesarcolemmal membranes are permeabilized or the SR Ca2+content is artificiallymanipulated,thus the cellular and molecular mechanisms underlying the regula-tion of Ca2+sparks in skeletal muscle remain largely ***,wediscovered that membrane deformation generated by osmotic stress induced arobust Ca2+spark response confined in close spatial proximity to the sarcolemmalmembrane in intact mouse muscle *** addition to Ca2+sparks,prolongedCa2+transients,termed Ca2+bursts,are also identified in intact skeletal *** induced Ca2+release events are reversible and repeatable,revealing a plas-tic nature in young muscle *** contrast,induced Ca2+sparks in aged muscleare transient and cannot be *** muscle fibers display un-controlled Ca2+sparks,where osmotic stress-induced Ca2+sparks are not revers-ible and they are no longer spatially restricted to the sarcolemmal *** of the mechanisms that underlie generation of osmotic stress-induced Ca2+sparks in skeletal muscle,and how these mechanisms are altered inpathology,will contribute to our understanding of the regulation of Ca2+homeo-stasis in muscle physiology and pathophysiology.

关键词： calcium signaling calcium channel aging muscular dystrophies endoplasmic reticulum

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Validation of a serum microRNA panel as biomarkers for early diagnosis of hepatocellular carcinoma post-hepatitis C infection in Egyptian patients

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World Journal of Gastroenterology 2017年第21期23卷 3864-3875页

作者： Moustafa Nouh Elemeery Ahmed noah Badr Marwa Anwar Mohamed Doaa Ahmed Ghareeb Medical Biotechnology Laboratory Genetic Engineering and Biotechnology Research DivisionNational Research Centre Toxicology and Food Contaminant Laboratory Food Science and Nutrition Research DivisionNational Research Centre Department of Chemical Pathology Medical Research InstituteAlexandria University Molecular Biology Laboratory Faculty of ScienceAlexandria University

AIM To investigate the prospective importance of serum micro(mi)RNAs(mi R-125 b, mi R-138 b, mi R-1269, mi R-214-5p, mi R-494, mi R375 and mi R-145) as early biomarkers for the diagnosis of hepatitis C virus(HCV)-related hepatocellular carcinoma(HCC).METHODS Two-hundred and fifty HCV4 a patients, 224 HCV4 aHCC patients, and 84 healthy controls were enrolled in the study. Expression levels of mi R214-5p, mi R-125 b, mi R-1269 and mi R-375 were quantified using quantitative real-time *** Expression of the selected mi RNAs in serum wassignificantly lower in HCC patients than in the healthy controls, except for mi R-1269 and mi R-494. There was a significant difference between HCC and HCV patients, in particular for HCC and late stage fibrosis, rather than HCV patients and early fibrosis. It is obvious that mi R-1269 was significantly upregulated in HCC cases compared to hepatic fibrosis cases. Each mi RNA can show HCC progression. Multivariate logistic regression analysis indicated that the tested panel of mi RNAs(mi R214-5p, mi R-125 b, mi R-1269 and mi R-375) represent accurate and specific indictors of HCC *** This study presents a panel of mi RNAs with strong power as putative diagnostic and prognostic biomarkers for HCV-induced HCC. Moreover, mi R-214-5p and mi R-1269 could be considered as early biomarkers for tracking the progress of liver fibrosis to HCC.

关键词： Micro RNA Hepatocellular carcinoma Fibrosis progression

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Prevalence of Hepatitis B and Associated Factors in the Garoua Central Prison,Cameroon: A Cross-Sectional Study

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Open Journal of Gastroenterology（肠胃病学期刊） 2024年第5期 174页

作者： Mohamadou Abdou Galdima Adamou Dodo Balkissou Guy Roger Nsenga Djapa Winnie Tatiana Bekolo Nga Gilles Aghoagni Antonin Wilson Ndjitoyap Ndam Ali Abas Mathurin Pierre Kowo Firmin Ankouane Andoulo Dominique noah noah Oudou Njoya Servais Albert Fiacre Eloumou Bagnaka

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Searching for ductile superconducting Heusler X_(2)YZ compounds

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npj Computational Materials 2023年第1期9卷 919-927页

作者： noah Hoffmann Tiago F.T.Cerqueira Pedro Borlido Antonio Sanna Jonathan Schmidt Miguel A.L.Marques Institut für Physik Martin-Luther-Universität Halle-WittenbergD-06099 HalleGermany CFisUC Department of PhysicsUniversity of CoimbraRua Larga 3004-516 CoimbraPortugal Max-Planck-Institut für Mikrostrukturphysik Weinberg 2D-06120 HalleGermany

Heusler compounds attract a great deal of attention from researchers thanks to a wealth of interesting properties,among which is *** we perform an extensive study of the superconducting and elastic properties of the cubic(full-)Heusler family using a mixture of ab initio methods,as well as interpretable and predictive machine-learning *** analyzing the statistical distributions of these properties and comparing them to anti-perovskites,we recognize universal behaviors that should be common to all conventional superconductors while others turn out to be specific to the material *** total,we discover a total of eight hypothetical materials with critical temperatures above 10 K to be compared with the current record of T_(c)=4.7 K in this ***,we expect most of these materials to be highly ductile,making them potential candidates for the manufacture of wires and tapes for superconducting magnets.

关键词： ductile compounds superconducting

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Sodium lanthanide fluoride core-shell nanocrystals： A general perspective on epitaxial shell growth

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Nano Research 2013年第8期6卷 547-561页

作者： noah J. J. Johnson Frank C. J. M. van Veggel Department of Chemistry University ofVictoria P.O. Box3065 Victoria British Columbia Canada V8W 3V6

Understanding the structural characteristics and growth mechanism（s） are essen-tial for generating core-shell nano-heterostructures with distinctive properties. Especially in lanthanide-based nanocrystals, rational design of the core-shell composition can be utilized to enhance/tune the optical properties of the final nanostructure, or can be used to integrate multiple functional applications （e.g., luminescent/magnetic）. In this article, we review the progress in our current understanding of the epitaxial shell growth in sodium lanthanide fluoride （NaLnF4） nanocrystals. In order to understand epitaxial shell growth the core nanocrystals have to be uniform, and to date the synthesis of high quality near uniform size/shape dispersion controlled synthesis of lanthanide-based nanocrystals has been achieved mainly with this class of nanocrystals. The progress in core-shell synthesis and the epitaxial shell growth mechanism in this class of nanocrystals （NaLnF4） are reviewed, and a general perspective is provided on the core-shell morphology based on different characterization techniques. While there has been tremendous progress in studying the impact of core-shell structures in various functional applications, this review also highlights, in our view, the still limited understanding of ways to control the core-shell morphology and it emphasizes some important, unanswered questions that remain to be addressed to maximize their performance.

关键词： upconvertingnanocrystals core-shell lanthanides epitaxy

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