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Influence of inter-grain cementation stiffness on the effective elastic properties of porous Bentheim sandstone

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第3期15卷 573-583页

作者： Bin Chen Jiansheng Xiang John-paul latham Department of Earth Science and Engineering Faculty of EngineeringImperial College LondonLondonSW72BXUK

Effective elastic properties of porous media are known to be significantly influenced by *** this paper,we investigated the influence of another critical factor,the inter-grain cementation stiffness,on the effective elastic properties of a granular porous rock(Bentheim sandstone)using an advanced numerical workflow with realistic rock microstructure and a theoretical ***,the disparity between the experimentally tested elastic properties of Bentheim sandstone and the effective elastic properties predicted by empirical equations was ***,a micro-computed tomography(CT)-scan based approach was implemented with digital imaging software AVIZO to construct the 3D(three-dimensional)realistic microstructure of Bentheim *** microstructural model was imported to a mechanics solver based on the 3D finite element model with inter-grain boundaries modelled by cohesive *** simulations were run to test the effective elastic properties for different shear and normal intergrain cementation ***,a relation between the macroscale Young’s modulus and inter-grain cementation stiffness was derived with a theoretical model which can also account for porosity *** the numerical and theoretical results indicate the influence of the inter-grain cementation stiffness,on the effective elastic properties is significant for porous *** calibrated normal and shear stiffnesses at the inter-grain boundaries are 1.2×10^(5) and 4×10^(4) Gpa/m,respectively.

关键词： porous sandstone Cohesive finite element model Grain-based model Rock microstructure Micro-computed tomography(CT)

THE ROLE OF RAILROAD IN THE DEVELOpMENT OF THE AMERICAN WEST—Railroad,Migration and Urban Growth

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Chinese Geographical Science 2001年第3期11卷 32-41页

作者： Lei Wang Michael latham Wuhan University Wuhan 430072 P.R. China

This paper explores the role of geographical expansion of railroads,one of the most important Fransporta-tion vehicles,in the history of American west development,analyses its implication on the unprecedented mi gration move-ment and the resulted urbanization i n the west and concludes with the fact that the appropriate interference b y the governm-net,especially in the early period,is vital to regional development pra ctice,because of market failure at t he initial stage,infrastructure constructio n conducted by the government always plays as the first impetus to any regional develop-ment *** through this brid ge,can some physical factors,such a s population,be attracted to feed th e back-ward *** a result,cities grow fa st and the region develops *** e xperience can be shared by all countr ***-sides reviewing the history of west development in America,focusing on t he relationship between railroads e xpansion and urban growth,which was realized thr ough population *** on the particular pattern of regional develop-ment between U.S and China is made as well at the *** is noted that despite of the common first impetus,govern-ment subsidies and the common final r esult,urbanization,the path for th e America is bottom-up,whereas that for China is top down,that is to say,developme nt should originate from big cities,then to towns,and finally radiate in to rural ar-eas.

关键词： migration railroad urban growth

The Virtual Geoscience Workbench, VGW: Open Source tools for discontinuous systems

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particuology 2010年第2期8卷 100-105页

作者： A. Munjiza J. Xiang X. Garcia J.p. latham G.G. Schiava D'Albano N.W.M. John Department of Engineering Queen Mary London University London UK Department of Earth Science and Engineering Imperial College London UK

In 1989 work began on merging finite and discrete elements. During 1990 algorithmic solutions for the new combined method were developed, together with a C-based implementation known as the Y code. In 2004 these developments and implementations were published as a textbook. Queen Mary University of London ~QMUL） and Imperial College are currently engaged in a research project to make Y codes in both 2D and 3D available in Open Source format and with mainly geoscience problems in mind. The result is a set of Open Source tools for Geoscience （VGW）, key components of which are summarised in this paper, together with illustrative range of simulation results. 2009 Chinese Society of particuology and Institute of process Engineering, Chinese Academy of Sciences. published by Elsevier B.V. All rights reserved.

关键词： Combined finite-discrete elementWorkbenchModellingGeoscience

DNA recovery and analysis from skeletal material in modern forensic contexts

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Forensic Sciences Research 2019年第1期4卷 51-59页

作者： Krista E.latham Jessica J.Miller Biology Department Human Identification CenterUniversity of IndianapolisIndianapolisINUSA

The generation of a DNA profile from skeletal remains is an important part of the identifica-tion process in both mass disaster and unidentified person cases. Since bones and teeth are often the only biological materials remaining after exposure to environmental conditions, intense heat, certain traumatic events and in cases where a significant amount of time has passed since the death of the individual, the ability to purify large quantities of informative DNA from these hard tissues would be beneficial. Since sampling the hard tissues for gen-etic analysis is a destructive process, it is important to understand those environmental and intrinsic factors that contribute to DNA preservation. This will serve as a brief introduction to these topics, since skeletal sampling strategies and molecular taphonomy have been dis-cussed in depth elsewhere. Additionally advances in skeletal DNA extraction and analysis will be discussed. Currently there is great variation in the DNA isolation methods used by laboratories to purify DNA from the hard tissues;however, a standardized set of short tan-dem repeat (STR) loci is analyzed by many US laboratories to allow for comparisons across samples and jurisdictions. Recent advances have allowed for the generation of DNA profiles from smaller quantities of template DNA and have expanded the number of loci analyzed for greater discriminatory power and predictions regarding the geographic ancestry and phenotype of the individual. Finally, utilizing databases and expanding the number of com-parison samples will be discussed in light of their role in the identification process.

关键词： Forensic sciences forensic anthropology forensic genetics individual identification molecular taphonomy skeletal DNA Extraction DNA profiles DNA databases

A three-dimensional feature extraction-based method for coal cleat characterization using X-ray μCT and its application to a Bowen Basin coal specimen

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 153-166页

作者： Yulai Zhang Matthew Tsang Mark Knackstedt Michael Turner Shane latham Euan Macaulay Rhys pitchers ARC Training Centre for M3D Innovation Research School of PhysicsAustralian National UniversityCanberraACT2601Australia Department of Materials physics Research School of PhysicsAustralian National UniversityCanberraACT2601Australia Anglo American Steelmaking Coal BrisbaneQLD4000Australia SCT Operations pty Ltd. WollongongNSW2500Australia

Cleats are the dominant micro-fracture network controlling the macro-mechanical behavior of *** understanding of the spatial characteristics of cleat networks is therefore important to the coal mining *** fracture networks(DFNs)are increasingly used in engineering analyses to spatially model fractures at various *** reliability of coal DFNs largely depends on the confidence in the input cleat *** of these parameters can be made from image-based three-dimensional(3D)characterization of coal cleats using X-ray micro-computed tomography(m CT).One key step in this process,after cleat extraction,is the separation of individual cleats,without which the cleats are a connected network and statistics for different cleat sets cannot be *** this paper,a feature extraction-based image processing method is introduced to identify and separate distinct cleat groups from 3D X-ray m CT ***(filters)representing explicit cleat features of coal are built and cleat separation is successfully achieved by convolutional operations on 3D coal *** new method is applied to a coal specimen with 80 mm in diameter and 100 mm in length acquired from an Anglo American Steelmaking Coal mine in the Bowen Basin,Queensland,*** is demonstrated that the new method produces reliable cleat separation capable of defining individual cleats and preserving 3D topology after ***-parallel fractures are also identified and separated,which has his-torically been challenging to delineate and rarely reported.A variety of cleat/fracture statistics is measured which not only can quantitatively characterize the cleat/fracture system but also can be used for DFN ***,variability and heterogeneity with respect to the core axis are *** heterogeneity is observed and suggests that the representative elementary volume(REV)of the cleat groups for engineering purposes may be a complex problem requ

关键词： Cleat separation Cleat statistics Feature extraction Discrete fracture network(DFN)modeling

latham法和牙龈——骨膜成形术治疗婴儿唇腭裂的初期评价

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华西口腔医学杂志 1991年第4期9卷 272-275页

作者：徐慧芬 Dr.Ralph latham Dr.Ralph Millard 华西医科大学口腔颌面外科学教研室加拿大西安大略大学美国迈阿密大学再造整形外科中心

简介了 latham 法和牙龈-骨膜成型术对唇腭裂婴儿的治疗及意义。观察测定了接受该治疗的44例唇腭裂患儿的咬合关系和牙槽裂区新骨形成的状况。结果发现:44例唇腭裂中,15例前牙反(牙合)。27例咬合片中有63%在齿槽裂区有不同程度的新骨生... 详细信息

简介了 latham 法和牙龈-骨膜成型术对唇腭裂婴儿的治疗及意义。观察测定了接受该治疗的44例唇腭裂患儿的咬合关系和牙槽裂区新骨形成的状况。结果发现:44例唇腭裂中,15例前牙反(牙合)。27例咬合片中有63%在齿槽裂区有不同程度的新骨生长。对该结果作了初期的评价,并提出了一些改进意见。

关键词： latham法唇裂腭裂骨形成

Technology　Encounters　China＇s　people　and　Culture：　The　United　Technologies　Corporation

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China Today 1995年第9期44卷 30-34页

作者： RICHARD latham

ＴｅｃｈｎｏｌｏｇｙＥｎｃｏｕｎｔｅｒｓＣｈｉｎａ＇ｓＰｅｏｐｌｅａｎｄＣｕｌｔｕｒｅ：ＴｈｅＵｎｉｔｅｄＴｅｃｈｎｏｌｏｇｉｅｓＣｏｒｐｏｒａｔｉｏｎＢｙＲＩＣＨＡＲＤＬＡＴＨＡＭＴＨＥＵｎｉｔｅｄＴｅｃｈｎｏｌｏ... 详细信息

ＴｅｃｈｎｏｌｏｇｙＥｎｃｏｕｎｔｅｒｓＣｈｉｎａ＇ｓＰｅｏｐｌｅａｎｄＣｕｌｔｕｒｅ：ＴｈｅＵｎｉｔｅｄＴｅｃｈｎｏｌｏｇｉｅｓＣｏｒｐｏｒａｔｉｏｎＢｙＲＩＣＨＡＲＤＬＡＴＨＡＭＴＨＥＵｎｉｔｅｄＴｅｃｈｎｏｌｏｇｉｅｓＣｏｒｐｏｒａｔｉｏｎ（Ｕ...

关键词： China

Interactions between hepatic iron and lipid metabolism with possible relevance to steatohepatitis

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World Journal of Gastroenterology 2012年第34期18卷 4651-4658页

作者： Umbreen Ahmed patricia S latham phillip S Oates Department of physiology Army Medical CollegeNational University of Sciences and TechnologyRawalpindi 46000Pakistan Department of pathology The George Washington School of Medicine and Health SciencesWashingtonDC 20037United States physiology M311 AnatomyPhysiology and Human BiologyUniversity of Western AustraliaPerthWA 6009 Australia

The liver is an important site for iron and lipid metabolism and the main site for the interactions between these two metabolic pathways. Although conflicting results have been obtained, most studies support the hypothesis that iron plays a role in hepatic lipogenesis. Iron is an integral part of some enzymes and transporters involved in lipid metabolism and, as such, may exert a direct effect on hepatic lipid load, intrahepatic metabolic pathways and hepatic lipid secretion. On the other hand, iron in its ferrous form may indirectly affect lipid metabolism through its ability to induce oxidative stress and inflammation, a hypothesis which is currently the focus of much research in the field of nonalcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD/NASH). The present review will first discuss how iron might directly interact with the metabolism of hepatic lipids and then consider a new perspective on the way in which iron may have a role in the two hit hypothesis for the progression of NAFLD via ferroportinand the iron regulatory molecule hepcidin. The review concludes that iron has important interactions with lipid metabolism in the liver that can impact on the development of NAFLD/NASH. More defined studies are required to improve our understanding of these effects.

关键词： Lipids Iron Non-alcoholic fatty liver dis-ease/non-alcoholic steatohepatitis Hepcidin Oxidativestress

无磁芯霍尔效应电流传感器IC的共模场抑制技术

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电子技术应用 2016年第8期42卷 8-10页

作者： Alexander latham Allegro MicroSystems LLC

利用霍尔效应可以测量集成载流回路产生的磁场,这种技术有许多优势。如果不使用磁芯会产生一些问题,那就是传感器IC容易受到杂散磁场的影响,霍尔板会出现高电流载流体或螺线管产生的杂散场,进而可能在测量电流时产生误差。解决这一问题... 详细信息

利用霍尔效应可以测量集成载流回路产生的磁场,这种技术有许多优势。如果不使用磁芯会产生一些问题,那就是传感器IC容易受到杂散磁场的影响,霍尔板会出现高电流载流体或螺线管产生的杂散场,进而可能在测量电流时产生误差。解决这一问题的根本方案是集成式差分电流传感技术。集成式差分电流传感可使杂散磁场产生的误差降低一到两个数量级。这样,此类传感器IC的用户就不必再担心杂散场干扰电流的测量,而且能简化pCB布局。

关键词：霍尔效应电流传感器差分电流传感共模场抑制杂散磁场