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Influence of railway wheel tread damage on wheel-rail impact loads and the durability of wheelsets

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Railway Engineering Science 2024年第1期32卷 20-35页

作者： Michele Maglio Tore Vernersson Jens C.o.Nielsen Anders Ekberg Elena Kabo CHARMEC Department of Mechanical and Maritime SciencesChalmers University of TechnologySE‑41296 GothenburgSweden

Dynamic wheel-rail contact forces induced by a severe form of wheel tread damage have been measured by a wheel impact load detector during full-scale field tests at different vehicle *** on laser scanning,the measured three-dimensional damage geometry is employed in simulations of dynamic vehicle-track interaction to calibrate and verify a simulation *** relation between the magnitude of the impact load and various operational parameters,such as vehicle speed,lateral position of wheel-rail contact,track stiffness and position of impact within a sleeper bay,is *** calibrated model is later employed in simulations featuring other forms of tread damage;their effects on impact load and subsequent fatigue impact on bearings,wheel webs and subsurface initiated rolling contact fatigue of the wheel tread are *** results quantify the effects of wheel tread defects and are valuable in a shift towards condition-based maintenance of running gear,and for general assessment of the severity of different types of railway wheel tread damage.

关键词： Wheel tread damage Rolling contact fatigue cluster Field measurements Dynamic vehicle-track interaction Wheel-rail impact load Wheelset durability

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Climate Trends and Their Impact on Sorghum production in Marigat, Baringo County: A Historical Analysis

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open Journal of Modern Hydrology 2024年第2期14卷 106-129页

作者： Kennedy o. okuku Japheth o. onyando Romulus o. okwany Clement K. Kiptum Department of Agricultural Engineering Egerton University Nakuru Kenya School of Engineering University of Eldoret Eldoret Kenya

Climate is subject to fluctuations in the majority of the world, mainly caused by rainfall as well as temperature variations. Climate fluctuations in Kenya have resulted in the spread of desert-like conditions in the ASALs region, such as Marigat in Baringo County. As a county, Baringo experiences great variations in climate annually, as well as uncertainty in expected rains, thereby negatively impacting the production of crops such as sorghum. This study applied the rainfall anomaly index (RAI), standardised precipitation evapotranspiration index (SpEI), standard precipitation index (SpI), and Mann-Kendall (MK) statistical test for trends on historical climatic data in analysing both temperature and precipitation data over the period 1990 to 2022 to determine their trend, patterns and how they affect the production of sorghum crops. The machine learning method (R studio) with inputs was used to calculate the SpI, SpEI, RAI and MK trend test. The rainfall varied from below average to above average during the study period with no clear pattern in the RAI, SpEI and SpI values. The years 2020 and 2000 stood out as they had higher and lower rainfall than usual, respectively. The Marigat area generally experienced more rainfall during the high/long rainfall season (AMJJ). The MK trend test on average monthly rainfall, SoND, AMJJ, and annual precipitation confirmed a positive trend in precipitation. However, the short rainy season (SoND) was found to be the most variable period for rainfall, and there was a slight increase in daily average temperatures during this season.

关键词： Trends precipitation Temperature RAI SpI SpEI and MK

Nonlinear Study on the Mechanical performance of Built-Up Cold-Formed Steel Concrete-Filled Columns under Compression

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3435-3465页

作者： oulfa Harrat Yazid Hadidane S.M.Anas Nadhim Hamah Sor Ahmed Farouk Deifalla paul o.Awoyera Nadia Gouider Civil Engineering Laboratory Faculty of TechnologyDepartment of Civil EngineeringBadji Mokhtar-Annaba UniversityP.O.Box 12Annaba23000Algeria Department of Civil Engineering Faculty of Engineering and TechnologyJamia Millia Islamia(A Central University)New Delhi110025India Civil Engineering Department University of GarmianKalar46021Iraq Department of Civil Engineering Harran UniversitySanliurfa63510Turkey Structural Engineering and Construction Management Department Future University in EgyptNew Cairo11835Egypt Department of Civil Engineering Covenant UniversityOta112233Nigeria

Given their numerous functional and architectural benefits,such as improved bearing capacity and increased resistance to elastic instability modes,cold-formed steel(CFS)built-up sections have become increasingly developed and used in recent years,particularly in the construction *** paper presents an analytical and numerical study of assembled CFS two single channel-shaped columns with different slenderness and configurations(backto-back,face-to-face,and box).These columns were joined by double-row rivets for the back-to-back and box configurations,whereas they were welded together for the face-to-face *** built-up columns were filled with ordinary concrete of good *** element models were applied,using ABAQUS software,to assess mechanical performance and study the influence of assembly techniques on the behavior of cold-formed columns under axial *** approaches based on Eurocode 3 and Eurocode 4 recommendations for un-filled and concrete-filled columns respectively were followed for the numerical analysis,and concrete confinement effects were also considered per American Concrete Institute(ACI)standards for face-to-face and box *** obtained results indicated a good correlation between the numerical results and the proposed analytical methodology which did not exceed 8%.The failure modes showed that the columns failed due to instabilities such as local and global buckling.

关键词： Cold-formed steel built-up sections slenderness rivets welded axial compression analytical approaches confinement buckling

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可编程多物理机制的力学超材料

力学进展 2024年

作者： p.Sinha T.Mukhopadhyay 印度理工学院航空工程系英国南安普顿大学工学院

力学超材料是一种有别于传统力学行为的工程材料，它源于人工可编程的微结构以及材料的固有属性。在过去的十年中，随着计算性能和复杂微观结构制造能力的巨大进步，力学超材料已经吸引了研究人员的广泛关注，因为它能够实现自然界中不... 详细信息

力学超材料是一种有别于传统力学行为的工程材料，它源于人工可编程的微结构以及材料的固有属性。在过去的十年中，随着计算性能和复杂微观结构制造能力的巨大进步，力学超材料已经吸引了研究人员的广泛关注，因为它能够实现自然界中不可能出现的多重物理属性。该领域迅速崛起的趋势之一是将材料行为和单元结构与其他不同的多种物理因素(如电场或磁场)以及温度、光或化学反应等刺激相结合，从而扩大按需主动调制力学响应的范围。在本文中，我们旨在概述有关超材料的力学和多物理性质调制的相关文献，重点介绍双能级设计的新兴趋势，着重讨论力学超材料在关键工程领域应用中的巨大潜力。本文对该领域的发展趋势、挑战和未来路线进行了系统深入分析，涵盖实时可重构性和功能编程、4D打印、纳米超材料、人工智能和机器学习、多物理折纸/剪纸、活性物质、软物质和保形超材料、复杂微结构制造、服役寿命效应和可扩展性等概念。

关键词：力学超材料按需特性调制多物理力学可编程物质双级点阵主动超材料刺激响应材料

Thermochemical co-conversion of biomass-plastic waste to biochar:a review

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Green Chemical Engineering 2024年第1期5卷 31-49页

作者： Adewale George Adeniyi Kingsley o.Iwuozor Ebuka Chizitere Emenike oluwaseun J.Ajala Samuel ogunniyi Kabir B.Muritala Department of Chemical Engineering Faculty of Engineering and TechnologyUniversity of IlorinIlorinP.M.B.1515Nigeria Department of Chemical Engineering Landmark UniversityOmu-AranKwara StateP.M.B.1001Nigeria Department of pure and Industrial Chemistry Nnamdi Azikiwe UniversityAwkaP.M.B.5025Nigeria Department of Chemistry Federal University of TechnologyBosso CampusMinnaNiger StateP.M.B.65Nigeria

Biomass and plastics are two of the most common municipal solid wastes globally that have continuously placed a burden on the *** is therefore important that they are properly *** coconversion offers a valuable opportunity to recycle biomass and plastics simultaneously into biochar,which reduces the time and cost of recycling them individually while producing a material with a wide range of *** study is a review of published literature that discusses the thermochemical co-processing of biomass and plastic wastes into *** was observed that co-pyrolysis and co-hydrothermal carbonization are the most commonly utilized technologies for this *** characteristics of different biomass and plastics that have been thermochemically converted into biochar were *** properties of the resulting biochar are affected by the feedstock composition,pre-treatment and blending ratio,the reactor’s configuration,reaction temperature,and the presence of a *** studies found that treating the feedstocks separately resulted in a lower yield of biochar than processing them *** biochar created by this procedure has been used as a soil additive and as an adsorbent for water *** perspectives and suggestions,such as the necessity for some technical advancement,biochar’s economic benefits,improved government participation,and raised social awareness,were also *** factors have the potential to propel this field of study to great horizons.

关键词： Biomass Co-pyrolysis plastic Thermochemical process Valorization

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Bile acid signaling in the regulation of whole body metabolic and immunological homeostasis

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Science China(Life Sciences) 2024年第5期67卷 865-878页

作者： Wei Jia Yitao Li Kenneth C.p.Cheung Xiaojiao Zheng School of Chinese Medicine Hong Kong Baptist UniversityHong KongChina Center for Translational Medicine and Shanghai Key Laboratory of Diabetes Mellitus Shanghai Sixth People's Hospital Affiliated to Shanghai JiaoTong University School of MedicineShanghai 200233China

Bile acids(BAs)play a crucial role in nutrient absorption and act as key regulators of lipid and glucose metabolism and immune *** the enterohepatic circulation,BAs are synthesized,metabolized,and reabsorbed,with a portion entering the vascular circulation and distributing *** allows BAs to interact with receptors in all major organs,leading to organ-organ interactions that regulate both local and global metabolic processes,as well as the immune *** review focuses on the whole-body effects of BA-mediated metabolic and immunological regulation,including in the brain,heart,liver,intestine,eyes,skin,adipose tissue,and *** BA synthesis and receptor signaling is a promising strategy for the development of novel therapies for various diseases throughout the body.

关键词： bile acid whole body metabolism immunity

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Downstaging strategies for unresectable hepatocellular carcinoma

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World Journal of Gastroenterology 2024年第20期30卷 2731-2733页

作者： Georgia Sofia Karachaliou Nikolaos Dimitrokallis Dimitrios p Moris Division of Gastroenterology Department of MedicineDuke University Medical CenterDurhamNC 27710United States First Department of Surgery&organ Transplant Unit Evangelismos General HospitalAthens 10676Greece Department of Surgery Duke University Medical CenterDurhamNC 27710United States

A significant number of patients with hepatocellular carcinoma(HCC)are usually diagnosed in advanced stages,that leads to inability to achieve *** options are focusing on downstaging a locally advanced *** is wellsupported in the literature that patients with HCC who undergo successful conversion therapy followed by curative-intent surgery may achieve a significant survival benefit compared to those who receive chemotherapy alone or those who are successfully downstaged with conversion therapy but not treated with *** artery infusion chemotherapy can be a potential downstaging strategy,since recent studies have demonstrated excellent outcomes in patients with colorectal liver metastatic disease as well as primary liver malignancies.

关键词： Unresectable hepatocellular carcinoma Hepatic arterial infusion chemotherapy Downstaging Hepatocellular carcinoma

MDCN:Modified Dense Convolution Network Based Disease Classification in Mango Leaves

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Computers, Materials & Continua 2024年第2期78卷 2511-2533页

作者： Chirag Chandrashekar K.p.Vijayakumar K.pradeep A.Balasundaram School of Computer Science and Engineering Vellore Institute of Technology(VIT)ChennaiIndia Center for Cyber physical Systems School of Computer Science and EngineeringVellore Institute of Technology(VIT)ChennaiIndia

The most widely farmed fruit in the world is *** the production and quality of the mangoes are hampered by many *** diseases need to be effectively controlled and ***,a quick and accurate diagnosis of the disorders is *** convolutional neural networks,renowned for their independence in feature extraction,have established their value in numerous detection and classification ***,it requires large training datasets and several parameters that need careful *** proposed Modified Dense Convolutional Network(MDCN)provides a successful classification scheme for plant diseases affecting mango *** model employs the strength of pre-trained networks and modifies them for the particular context of mango leaf diseases by incorporating transfer learning *** data loader also builds mini-batches for training the models to reduce training ***,optimization approaches help increase the overall model’s efficiency and lower computing *** employed on the MangoLeafBD Dataset consists of a total of 4,000 *** the experimental results,the proposed system is compared with existing techniques and it is clear that the proposed algorithm surpasses the existing algorithms by achieving high performance and overall throughput.

关键词： Leaf disease detection deep convolutional neural networks transfer learning optimization MangoLeafBD Dataset

Machine learning in liver surgery:Benefits and pitfalls

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World Journal of Clinical Cases 2024年第12期12卷 2134-2137页

作者： Rafael Calleja Manuel Durán María Dolores Ayllón Ruben Ciria Javier Briceño Hepatobiliary Surgery and Liver Transplantation Unit Hospital Universitario Reina SofíaMaimonides Biomedical Research Institute of CordobaCórdoba 14004Spain

The application of machine learning(ML)algorithms in various fields of hepatology is an issue of ***,we must be cautious with the *** this letter,based on a published ML prediction model for acute kidney injury after liver surgery,we discuss some limitations of ML models and how they may be addressed in the *** the future faces significant challenges,it also holds a great potential.

关键词： Machine learning Liver surgery Artificial intelligence Random forest prediction model