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Coupled Inversion of Pressure and Tiltmeter Data for Mapping Hydraulic Fracture geometry

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Acta Mechanica Solida Sinica 2024年第3期37卷 396-405页

作者： Zuorong Chen Xiaofang Jiang Zhejun Pan robert g.Jeffrey National Key Laboratory of Continental Shale Oil Northeast Petroleum UniversityDaqing163318China SCT Operation Pty.Ltd. PO Box 824WollongongNSW2520Australia

Pressure and tilt data are jointly inverted to simultaneously map the orientation and dimensions of a hydraulic *** deformation induced by a fracture under internal pressure is modeled using the distributed dislocation *** planar fracture is represented by four quarter ellipses,joined at the center and sharing *** configuration provides a straightforward model for characterizing asymmetric fracture *** inverse problem of mapping the fracture geometry is formulated using the Bayesian probabilistic method,combining the a priori information on the fracture model with updated information from pressure and tilt *** the nonlinear inverse problem is achieved by pseudo-randomly sampling the posterior probability distribution through the Markov chain Monte Carlo *** resulting posterior probability distribution is then explored to assess uncertainty,resolution,and correlation between model *** experiments are conducted to verify the accuracy and validity of the proposed analysis method in mapping the fracture geometry using synthetic pressure and tilt data.

关键词： Hydraulic fracture mapping Coupled inversion Tilt Treating pressure

Hydrodynamic function and spring constant calibration of FluidFM micropipette cantilevers

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Microsystems & Nanoengineering 2024年第1期10卷 277-286页

作者： Attila Bonyár Ágoston g.Nagy Hans gunstheimer gotthold Fläschner robert Horvath Department of Electronics Technology Faculty of Electrical Engineering and InformaticsBudapest University of Technology and EconomicsBudapestHungary Nanobiosensorics Laboratory Institute of Technical Physics and Materials ScienceCentre for Energy ResearchHUN-RENBudapestHungary Nanosurf Ag Gräubernstrasse 12CH-4410 LiestalSwitzerland

Fluidic force microscopy(FluidFM)fuses the force sensitivity of atomic force microscopy with the manipulation capabilities of microfluidics by using microfabricated cantilevers with embedded fluidic *** innovation initiated new research and development directions in biology,biophysics,and material *** acquire reliable and reproducible data,the calibration of the force sensor is ***,the hollow FluidFM cantilevers contain a row of parallel pillars inside a rectangular *** precise spring constant calibration of the internally structured cantilever is far from trivial,and existing methods generally assume simplifications that are not applicable to these special types of *** addition,the Sader method,which is currently implemented by the FluidFM community,relies on the precise measurement of the quality factor,which renders the calibration of the spring constant sensitive to *** this study,the hydrodynamic function of these special types of hollow cantilevers was experimentally determined with different *** on the hydrodynamic function,a novel spring constant calibration method was adapted,which relied only on the two resonance frequencies of the cantilever,measured in air and in a *** on these results,our proposed method can be successfully used for the reliable,noise-free calibration of hollow FluidFM cantilevers.

关键词： spring cantilever function

Predicting the coefficient of friction in a sliding contact by applying machine learning to acoustic emission data

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Friction 2024年第6期12卷 1299-1321页

作者： robert gUTIERREZ Tianshi FANg robert MAINWARINg Tom REDDYHOFF Tribology group Department of Mechanical EngineeringImperial College LondonExhibition RoadLondon SW72AZUK Shell global Solutions(US)Inc.Shell Technology Center Houston 3333 Highway 6 SouthHoustonTX 77082USA Shell International Petroleum Company Limited Shell CentreYork RoadLondon SE17NAUK

It is increasingly important to monitor sliding interfaces within machines,since this is where both energy is lost,and failures *** emission(AE)techniques offer a way to monitor contacts remotely without requiring transparent or electrically conductive ***,acoustic data from sliding contacts is notoriously complex and difficult to ***,we simultaneously measure coefficient of friction(with a conventional force transducer)and acoustic emission(with a piezoelectric sensor and high acquisition rate digitizer)produced by a steel‒steel rubbing *** data is then used to train machine learning(ML)algorithms(e.g.,gaussian process regression(gPR)and support vector machine(SVM))to correlated acoustic emission with *** training requires the dense AE data to first be reduced in size and a range of processing techniques are assessed for this(e.g.,down-sampling,averaging,fast Fourier transforms(FFTs),histograms).Next,fresh,unseen AE data is given to the trained model and the resulting friction predictions are compared with the directly measured *** is excellent agreement between the measured and predicted friction when the gPR model is used on AE histogram data,with root mean square(RMS)errors as low as 0.03 and Pearson correlation coefficients reaching ***,predictions remain accurate despite changes in test conditions such as normal load,reciprocating frequency,and stroke *** paves the way for remote,acoustic measurements of friction in inaccessible locations within machinery to increase mechanical efficiency and avoid costly failure/needless maintenance.

关键词： acoustic emission condition monitoring friction machine learning gaussian process regression support vector machine

Importance of periphytic biofilms for carbon cycling in paddy fields:A review

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Pedosphere 2024年第1期34卷 36-43页

作者： Lei ZHOU Yonghong WU Junzhuo LIU Pengfei SUN Ying XU Jan DOLFINg robert gMSPENCER Erik JEPPESEN State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Zigui Three gorges Reservoir Ecosystem Observation and Research Station of Ministry of Water Resources of the People's Republic of ChinaYichang 443605China College of Nanjing University of Chinese Academy of SciencesNanjing 211135China Faculty of Energy and Environment Northumbria UniversityNewcastle upon Tyne NE18QHUK Department of Earth Ocean and Atmospheric ScienceFlorida State UniversityTallahassee FL 32306USA Department of Ecoscience&Centre for Water Technology(WATEC) Aarhus UniversityAarhus DK-8000Denmark Sino-Danish Centre for Education and Research Beijing 100049China Limnology Laboratory Department of Biological Sciences and Centre for Ecosystem Research and Implementation(EKOSAM)Middle East Technical UniversityAnkara 06800Turkiye Institute of Marine Sciences Middle East Technical UniversityMersin 33731Turkiye

Paddy fields play an important role in global carbon(C) cycling and are an important source of methane(CH_(4)) emissions. Insights into the processes influencing the dynamics of soil organic C(SOC) in paddy fields are essential for maintaining global soil C stocks and mitigating climate change. Periphytic biofilms composed of microalgae, bacteria, and other microorganisms are ubiquitous in paddy fields, where they directly mediate the transfer of elements at the soil-water interface. However, their contributions to C turnover and exchange have been largely neglected. Periphytic biofilms affect and participate in soil C dynamics by altering both abiotic(e.g., pH and redox potential) and biotic conditions(e.g., microbial community composition and metabolism). This review summarizes the contributions of periphytic biofilms to soil C cycling processes, including carbon dioxide fixation, SOC mineralization, and CH_(4) emissions. Future research should be focused on: i) the mechanisms underlying periphytic biofilm-induced C fixation and turnover and ii) quantifying the contributions of periphytic biofilms to soil C uptake, stabilization, and sequestration in paddy fields.

关键词： carbon fixation carbon mineralization carbon sequestration methane emission microbial aggregates soil organic carbon

Next generation multiple access for IMT towards 2030 and beyond

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Science China(Information Sciences) 2024年第6期67卷 448-450页

作者： Zhiguo DINg robert SCHOBER Pingzhi FAN H.Vincent POOR Department of Computer and Information Engineering Khalifa University Department of Electrical and Electronic Engineering University of Manchester Institute for Digital Communications Friedrich Alexander-University Erlangen-Nurnberg (FAU) CSNMT International Cooperation Research Center (MoST) Southwest Jiaotong University Department of Electrical and Computer Engineering Princeton University

Multiple access techniques are fundamental to the design of wireless communication systems,since many crucial components of such systems depend on the choice of the multiple access technique[1].For example,the use of ...

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Commentary on “Why people should run after positive affective experiences instead of health benefits”

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Journal of Sport and Health Science 2024年第4期13卷 451-452页

作者： Ting Wang Jinghua Chen robert Schinke Liye Zou Body-Brain-Mind Laboratory School of PsychologyShenzhen UniversityShenzhen 518060China School of Kinesiology and Health Sciences Laurentian UniversitySudburyON P3E 2C6Canada

Maltagliati et al.1 recently highlighted the vital role of affective experiences in promoting physical activity(PA).The authors suggested that positive affective experiences,rather than health benefits,can tip the balance in favor of PA over sedentary *** authors proposed a new formal decision model between PA and sedentary alternatives and reported that when health benefits are the unique reason to action,the costs of PA(e.g.,effort)and the subjective value(SV)of sedentary alternatives(V_(sed))are the main drivers of decision-making processes.

关键词： benefits formal decision

Public health importance of light intensity physical activity

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Journal of Sport and Health Science 2024年第5期13卷 674-675页

作者： robert Ross Ian Janssen Mark S.Tremblay School of Kinesiology and Health Studies Queen’s UniversityKingstonON K7L 3N6Canada School of Medicine Division of Endocrinology and MetabolismQueen’s UniversityKingstonON K7L 3N6Canada Healthy Active Living and Obesity Research group Children’s Hospital of Eastern Ontario Research InstituteOttawaON K1H 8L1Canada Department of Pediatrics University of OttawaOttawaON K1H 8L1Canada

*** intensity physical activity(PA)benefits health PA guidelines worldwide recommend that adults accumulate 150 min of moderate intensity or 75 min of vigorous intensity PA(moderate-to-vigorous PA(MVPA))weekly to achieve health benefits.1-3 Absent from these guidelines are recommendations for light intensity PA(LPA,e.g.,walking at a leisurely pace of 3 km/h or less,equivalent to 1.5-2.9 metabolic equivalents).

关键词： intensity light benefits

Effect of reaction and post-treatment conditions on physico-chemical properties of magnetic iron oxide nano-particles Author links open overlay panel

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Particuology 2024年第8期91卷 155-167页

作者： Masome Moeni Mohamed Edokali Matthew Rogers Oscar Cespedes Louey Tliba Tamseela Habib robert Menzel Ali Hassanpour School of Chemical and Process Engineering Faculty of Engineering and Physical ScienceUniversity of LeedsLeedsLS29JTUK School of Physics and Astronomy Faculty of Engineering and Physical ScienceUniversity of LeedsLeedsLS29JTUK Mechanical Engineering Department University of Engineering&TechnologyLahorePakistan School of Chemistry Faculty of Engineering and Physical ScienceUniversity of LeedsLeedsLS29JTUK

Poor stability and dispersibility,as well as aggregation are considered as major challenges in clinical application of iron oxide nanoparticles(IONPs).Several studies have shown that the synthesis parameters and post-synthesis treatments e.g.,drying methods,have the capability to improve the particles'***,we investigate the combined effect of synthesis and post-treatment parameters on the particle size,stability and magnetism of ***(Fe_(3)O_(4))NPs were prepared via co-precipitation and post-treated using different methods,i.e.(i)freeze dried at-53℃,0.133 mbar for 48 h(liquid nitrogen frozen(LFD)and freezer frozen(FFD)),(ii)vacuum oven dried(VOD)at 60℃for 24 h,and(iii)kept wet colloidal(WET),dispersed in deionized *** Fe_(3)O_(4)NPs’chemical functional groups,size,shape,crystallinity,stability,aggregation,porosity,and magnetic properties were further analysed using different characterisation *** results showed that,while the WET sample had the best stability and significantly less aggregation at different temperatures,amongst post-treated Fe_(3)O_(4)NPs,LFD sample exhibited the best stability(up to 37℃),dispersion and smallest polydispersity ***,all dried NPs had superparamagnetic characteristics,while,LFD Fe_(3)O_(4)NPs had better magnetic properties and stability than other drying methods.

关键词： Iron oxide nanoparticles Co-precipitation Stability Aggregation Magnetic properties

Endotoxin-induced alterations of adipose tissue function:a pathway to bovine metabolic stress

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1391-1407页

作者： Miguel Chirivi g.Andres Contreras Department of Large Animal Clinical Sciences Michigan State UniversityEast LansingMIUSA

During the periparturient period, dairy cows exhibit negative energy balance due to limited appetite and increased energy requirements for lactogenesis. The delicate equilibrium between energy availability and expenditure puts cows in a state of metabolic stress characterized by excessive lipolysis in white adipose tissues(AT), increased production of reactive oxygen species, and immune cell dysfunction. Metabolic stress, especially in AT, increases the risk for metabolic and inflammatory diseases. Around parturition, cows are also susceptible to endotoxemia. Bacterial-derived toxins cause endotoxemia by promoting inflammatory processes and immune cell infiltration in different organs and systems while impacting metabolic function by altering lipolysis, mitochondrial activity, and insulin sensitivity. In dairy cows, endotoxins enter the bloodstream after overcoming the defense mechanisms of the epithelial barriers, particularly during common periparturient conditions such as mastitis, metritis, and pneumonia, or after abrupt changes in the gut microbiome. In the bovine AT, endotoxins induce a pro-inflammatory response and stimulate lipolysis in AT, leading to the release of free fatty acids into the bloodstream. When excessive and protracted, endotoxin-induced lipolysis can impair adipocyte's insulin signaling pathways and lipid synthesis. Endotoxin exposure can also induce oxidative stress in AT through the production of reactive oxygen species by inflammatory cells and other cellular components. This review provides insights into endotoxins' impact on AT function, highlighting the gaps in our knowledge of the mechanisms underlying AT dysfunction, its connection with periparturient cows' disease risk, and the need to develop effective interventions to prevent and treat endotoxemia-related inflammatory conditions in dairy cattle.

关键词： Adipose tissue dysfunction Endotoxin Inflammation Insulin resistance