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Defect assessment of welded specimen considering weld induced residual stresses using SINtAP procedure and FEA

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transactions of Nonferrous Metals Society of China 2013年第5期23卷 1452-1458页

作者： M.JEYAKUMAR t.christopher Faculty of Mechanical Engineering Sardar Raja College of Engineering Faculty of Mechanical Engineering Government College of Engineering

the defect assessment in butt-welded joint of AStM A36 steel plates and 7075-t7351 aluminum alloy plates containing transverse through thickness crack was analyzed using SINtAP procedure and FEA incorporating weld induced residual stresses. Weld induced longitudinal residual stress profile can be obtained through SINtAP procedure, FEA or experimental analysis. this residual stress profile can be fitted with the trapezoidal residual stress profile available in SINtAP. For three different cases, crack length and residual stress intensity factor （SIF） are calculated and its comparison with the results obtained through FEA is plotted with respect to crack length. the stress intensity factor for mechanical loading is also plotted in the same graph. Using this graphical plot, the total SIF, including residual stress and mechanical loading, can be calculated for any particular crack size. the total SIF can be compared with the fracture toughness of the material for damage tolerance analysis. Also a failure assessment diagram is drawn for welded 7075-t7351 aluminum alloy plates with different crack sizes for as-welded （only residual stress） and mechanical loading along with the existing weld induced residual stresses to show the safety level for a particular crack size and mechanical loading.

关键词： failure assessment diagram fracture toughness stress intensity factor through thickness crack welding residual stress

Fracture strength evaluation of titanium alloys using modified average stress criterion

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transactions of Nonferrous Metals Society of China 2013年第4期23卷 1072-1079页

作者： H.BRIGHtON ISAAC JOHN t.christopher Sardar Raja College of Engineering AlangulamTirunelveli-627808India Government College of Engineering PerumalpuramTirunelveli-627007India

Structural integrity procedures were used to demonstrate the fitness for the purpose of engineering components transmitting loads. the prediction of the fracture strength of titanium alloys containing sharp notches through the damage model depends on the un-notched strength and the critical length of the damage zone ahead of the notch. In general, the critical length of the damage zone depends on the material, specimen, and size of the sharp notch. Modifications were made in one of the stress fracture criteria known as the average stress criterion for accurate prediction of notched tensile strength of titanium alloy specimen containing sharp notches. to examine the adequacy of these modifications, fracture data of center-cracked titanium alloys with various thicknesses are considered. the notched （fracture） strength estimates are found to be close to the test results. the modified average stress criterion is very simple to predict the notched tensile strength.

关键词： titanium alloys center crack tensile specimen stress criterion failure assessment diagram fracture strength

Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

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Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： christopher J.O’Connell Matthew J.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA James L.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

traumatic brain injury(tBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).tBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

Comparative analysis of empirical and deep learning models for ionospheric sporadic E layer prediction

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Earth and Planetary Physics 2025年第1期9卷 10-19页

作者： BingKun Yu PengHao tian XiangHui Xue christopher JScott HaiLun Ye JianFei Wu Wen Yi tingDi Chen XianKang Dou Institute of Deep Space Sciences Deep Space Exploration LaboratoryHefei 230088China CAS Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China Department of Meteorology University of ReadingReading RG66BBUK

Sporadic E(Es)layers in the ionosphere are characterized by intense plasma irregularities in the E region at altitudes of 90-130 *** they can significantly influence radio communications and navigation systems,accurate forecasting of Es layers is crucial for ensuring the precision and dependability of navigation satellite *** this study,we present Es predictions made by an empirical model and by a deep learning model,and analyze their differences comprehensively by comparing the model predictions to satellite RO measurements and ground-based ionosonde *** deep learning model exhibited significantly better performance,as indicated by its high coefficient of correlation(r=0.87)with RO observations and predictions,than did the empirical model(r=0.53).this study highlights the importance of integrating artificial intelligence technology into ionosphere modelling generally,and into predicting Es layer occurrences and characteristics,in particular.

关键词： ionospheric sporadic E layer radio occultation ionosondes numerical model deep learning model artificial intelligence

transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN t.ASGHAR Z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

this paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. the influence of magnetic fields is also inspected in terms of their physical characteristics. to depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).the effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： hybrid nanofluid oscillating curved stretchable sheet gyrotactic microorganism Cattaneo-Christov heat and mass flux chemical reaction analytical solution O368

Role of the histone methyltransferases Ezh2 and Suv4-20h1/Suv4-20h2 in neurogenesis

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Neural Regeneration Research 2023年第3期18卷 469-473页

作者： christopher t.Rhodes Chin-Hsing Annie Lin Eunice Kennedy Shriver National Institute of Child Health and Human Development(NICHD) National Institutes of Health(NIH)BethesdaMDUSA Department of Integrative Biology University of Texas at San AntonioSan AntonioTXUSA University of texas at San Antonio Neurosciences Institute San AntonioTXUSA

Mechanisms regulating neurogenesis involve broad and complex processes that represent intriguing therapeutic targets in the field of regenerative *** influential factor guiding neural stem cell proliferation and cellular differentiation during neurogenesis are epigenetic *** present an overview of epigenetic mechanisms including chromatin structure and histone modifications;and discuss novel roles of two histone modifiers,Ezh2 and Suv4-20h1/Suv4-20h2(collectively referred to as Suv4-20h),in neurodevelopment and *** review will focus on broadly reviewing epigenetic regulatory components,the roles of epigenetic components during neurogenesis,and potential applications in regenerative medicine.

关键词： adult neurogenesis epigenetic Ezh2 histone co-regulation histone modification neurodevelopment neurogenesis regenerative medicine Suv4-20h

Molecular anatomy and pathogenic actions of Helicobacter pylori CagA that underpin gastric carcinogenesis

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Cellular & Molecular Immunology 2020年第1期17卷 50-63页

作者： Atsushi takahashi-Kanemitsu christopher t.Knight Masanori Hatakeyama Department of Microbiology Graduate School of MedicineThe University of TokyoTokyoJapan

Chronic infection with Helicobacter pylori cagA-positive strains is the strongest risk factor for gastric *** cagA gene product,CagA,is delivered into gastric epithelial cells via the bacterial type IV secretion *** CagA then undergoes tyrosine phosphorylation at the Glu-Pro-Ile-tyr-Ala(EPIYA)motifs in its C-terminal region and acts as an oncogenic scaffold protein that physically interacts with multiple host signaling proteins in both tyrosine phosphorylation-dependent and-independent *** of CagA using in vitro cultured gastric epithelial cells has indicated that the nonphysiological scaffolding actions of CagA cell-autonomously promote the malignant transformation of the cells by endowing the cells with multiple phenotypic cancer hallmarks:sustained proliferation,evasion of growth suppressors,invasiveness,resistance to cell death,and genomic *** expression of CagA in mice leads to in vivo oncogenic action of CagA without any overt *** in vivo oncogenic activity of CagA is further potentiated in the presence of chronic *** Helicobacter pylori infection triggers a proinflammatory response in host cells,a feedforward stimulation loop that augments the oncogenic actions of CagA and inflammation is created in CagA-injected gastric *** that Helicobacter pylori is no longer colonized in established gastric cancer lesions,the multistep nature of gastric cancer development should include a“hit-and-run”process of CagA ***,acquisition of genetic and epigenetic alterations that compensate for CagA-directed cancer hallmarks may be required for completion of the“hit-and-run”process of gastric carcinogenesis.

关键词： cagA/CagA Helicobacter pylori SHP2 PAR1 inflammation “hit-and-run”carcinogenesis

Introduction to social sensing and big data computing for disaster management

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International Journal of Digital Earth 2019年第11期12卷 1198-1204页

作者： Zhenlong Li Qunying Huang christopher t.Emrich Geoinformation and Big Data Research Laboratory Department of GeographyUniversity of South CarolinaColumbiaSCUSA Department of Geography University of Wisconsin-MadisonMadisonWIUSA School of Public Administration and National Center for Integrated Coastal Research University of Central FloridaOrlandoFLUSA

traditional data collection methods such as remote sensing and field surveying often fail to offer timely information during or immediately following disaster *** sensing enables all citizens to become part of a large sensor network,which is low cost,more comprehensive,and always broadcasting situational awareness ***,data collected with social sensing is often massive,heterogeneous,noisy,unreliable from some aspects,comes in continuous streams,and often lacks geospatial reference ***,these issues represent a grand challenge toward fully leveraging social sensing for emergency management decision making under extreme ***,big data computing methods and technologies such as high-performance computing,deep learning,and multi-source data fusion become critical components of using social sensing to understand the impact of and response to the disaster events in a timely *** special issue captures recent advancements in leveraging social sensing and big data computing for supporting disaster *** analyzed within these papers are some of the promises and pitfalls of social sensing data for disaster relevant information extraction,impact area assessment,population mapping,occurrence patterns,geographical disparities in social media use,and inclusion in larger decision support systems.

关键词： Social media VGI big data natural hazards spatial computing

Modelling of the behavior of marine oil spills: applications based on random walk techniques

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Journal of Environmental Sciences 2000年第1期12卷 3-8页

作者： Li, Zhi-Wei Mead, christopher t. Zhang, Shu-Shen Dept. of Environ. Sci. and technol. Dalian University of Technology Dalian 116012 China HR Wallingford Howbery Park Wallingford Oxon OX10 8BA United Kingdom

A numerical model has been developed to simulate the transport and fate of oil spilled at sea. the model combines the transport and fate processes of spilled oil with the random walk technique. Oil movement under the influence of tidal currents, wind driven currents, and turbulent eddies is simulated by the PLUME RW dispersion model developed by HR Wallingford. the weathering processes in the model represent physical and chemical changes of soil slicks with time, and comprise mechanical spreading, dispersion, evaporation and emulsification. Shoreline stranding is determined approximately using a capacity method for different shoreline types. this paper presents details of the model, and describe the results of various sensitivity tests. the model is suitable for oil spill contingency planning.

关键词： oil spill modelling random walk technique CLC number: tQ021 4 Document code: A