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Numerical study of novel OME_(1-6) combustion mechanism and spray combustion at changed ambient environments

Frontiers in Energy 2024年第4期18卷 483-505页

作者： Frederik WIESMANN Zeyan QIU Dong HAN Lukas STRAUβ Sebastian RIEβ Michael WENSING thomas LAUER Institute of Powertrains and Automotive Technology TU Wien1060 ViennaAustria Key Laboratory for Power Machinery and Engineering of Ministry of Education Shanghai Jiao Tong UniversityShanghai 200240China Professorship for Fluid Systems Technology Friedrich-AlexanderUniversität Erlangen-Nürnberg91058 ErlangenGermany

For a climate-neutral future mobility,the socalled e-fuels can play an essential ***,oxygenated e-fuels containing oxygen in their chemical formula have the additional potential to burn with significantly lower soot *** particular,polyoxymethylene dimethyl ethers or oxymethylene ethers(PODEs or OMEs)do not contain carbon-carbon bonds,prohibiting the production of soot precursors like acetylene(C_(2)H_(2)).These properties make OMEs a highly interesting candidate for future climate-neutral compression-ignition ***,to fully leverage their potential,the auto-ignition process,flame propagation,and mixing regimes of the combustion need to be *** achieve this,efficient oxidation mechanisms suitable for computational fluid dynamics(CFD)calculations must be developed and *** present work aims to highlight the improvements made by developing an adapted oxidation mechanism for OME1-6 and introducing it into a validated spray combustion CFD model for *** simulations were conducted for single-and multi-injection patterns,changing ambient temperatures,and oxygen *** results were validated against high-pressure and high-temperature constantpressure chamber ****-chemiluminescence measurements accomplished the characterization of the auto-ignition *** experiments and simulations were conducted for two different *** improvements concerning the prediction of the ignition delay time were accomplished while also retaining an excellent agreement for the flame lift-off *** spatial zones of high-temperature reaction activity were also affected by the adaption of the reaction *** showed a greater tendency to form OH^(*) radicals within the center of the spray in accordance with the experiments.

关键词： oxygenated fuels reaction kinetics oxidation mechanisms computational fluid dynamics(CFD) oxymethylene ethers(OME) e-fuels multiinjection spray-combustion

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Health economics for intra-capsular hip fractures undertaking fixation

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World Journal of Orthopedics 2024年第1期15卷 30-38页

作者： Anatole Wiik thomas Ashdown Ian Holloway Department of Surgery Trauma and OrthopaedicsLondon North West University HealthcareLondon HA13UJUnited Kingdom Department of Surgery Trauma and OrthopaedicsLondon North West University HospitalLondon HA13UJUnited Kingdom

BACKGROUND Hip fracture is a common musculoskeletal injury in the elderly requiring surgery *** operative mainstay of intra-capsular hip fractures is arthroplasty with a smaller proportion for *** To determine the most beneficial method of fixation for patients with intracapsular hip *** A registered audit from 2012-2018 was conducted on all intra-capsular hip fractures treated with 2 commonly used fixation *** notes,electronic records and clinical codes for cost benefit were evaluated.A validated quality of life measure was collected at least 1 year after *** A total of 83 patients were identified with intra-capsular fractures undergoing fixation during the retrospective *** were 47 cannulated cancellous screw and 36 sliding hip screw fixations with the case mix comparable for age,gender,co-morbidities and fracture *** was no significant difference in blood loss,tip apex distance,radiation exposure,length of stay,radiological union time,collapse,avascular necrosis or re-operation between fixation *** regression analysis demonstrated displaced intracapsular hip fractures correlated significantly with an undesirable outcome conferring a relative odds ratio of *** were 9(19%)and 4(11%)patients respectively,who required *** was no significant difference in health resource group tariff and implant cost with comparable EQ-5D and visual CONCLUSION No significant advantage was identified with differing fixation type,but irrespective there were a high number of patients requiring *** was predicted by initial fracture displacement and patient *** may need to be carefully considered for health economics and patient benefit.

关键词： Hip fracture Fixation Patient reported outcome measure Cost

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BLE beacons for sample position estimation in a life science automation laboratory

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Transportation Safety and Environment 2024年第3期6卷 111-123页

作者： Haiping Wu Steffen Junginger thomas Roddelkopf Hui Liu Kerstin Thurow Institute of Artificial Intelligence&Robotics(IAIR) Key Laboratory of Traffic Safety on Track of Ministry of EducationSchool of Traffic and Transportation EngineeringCentral South UniversityChangsha 410075HunanChina Institute of Automation(IAT) University of Rostock18119 RostockGermany Center of Life Science Automation(celisca) University of Rostock18119 RostockGermany

Estimation of the sample position is essential for working process monitoring and management in the life science automation lab*** low-energy(BLE)beacons have the advantages of low price,small size and low energy consumption,which make them a promising solution for sample position estimation in the automated *** fingerprinting models have been proposed to achieve indoor localization with the received signal strength(RSS)***,most of the research depends on intensive beacon *** estimation,which depends entirely on one beacon,is more suitable for sample position estimation in large automated *** complexity of the life science automation laboratory environment brings challenges to the traditional path loss model(PLM),which is a widely used radio wave propagation model-based proximity estimation *** this paper,BLE sensing devices for sample position estimation are *** BLE beacon-based proximity estimation is discussed in the framework of machine learning,in which the support vector regression(SVR)is utilized to model the nonlinear relationship between the RSS data and distance,and the Kalman filter is utilized to decrease the RSS data *** experimental results over different environments indicate that the SVR outperforms the PLM significantly,and provides 1 m absolute errors for more than 95%of the testing *** Kalman filter brings benefits to stable distance *** from proximity-based sample position estimation,the proposed framework turned out to be effective in position estimation between parallel workbenches and position estimation on an automated workstation.

关键词： BLE beacon position estimation proximity estimation received signal strength(RSS) support vector regression(SVR) life science automation laboratory

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Clean,but not green:Emission assessment,forecast modelling and policy solutions for plastic microbeads from personal care products in India

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Emerging Contaminants 2024年第3期10卷 124-133页

作者： Riya Kumbukattu Alex thomas Maes Suja Purushothaman Devipriya School of Environmental Studies Cochin University of Science and Technology682022India GRID-Arendal Teaterplassen 34836ArendalNorway

Intentionally added plastic microbeads in personal care products(PCP)are an underestimated source of *** microbeads are added as fillers,to increase product volume or aesthetics and allegedly have the purpose of cleansing and *** assess and forecast microbead emissions in India,this study analysed 45 items from four different categories of personal care products:face wash,face scrub,shower gel and body scrub available in the Indian market and determined microbead abundance,size,colour,shape and polymer ***,an emission estimation and time-seriesbased forecast for 2030 was done using ARIMA(0,2,0)for individual categories and *** results indicate that 45.00%of the products contained irregular or smooth microplastics,with Polyethylene being the dominant polymer,followed by Polypropylene,Polystyrene,Polyurethane and Polycaprolactone.A significant number of products(23.33%)contained cellulose microbeads,with ambiguity regarding their *** identified microbeads were mainly irregular in shape and granular in texture,especially ***/transparent colour dominated the identified microbeads,followed by blue,pink,yellow,red and *** 1.34%of the total product contained plastic microbeads,with 5.04%and 0.04%being the highest and lowest percentages *** average size of microbeads was found to be 640.74 mm,452.45 mm,556.66 mm and 606.30 mm in different *** overall annual emission estimation was 3.51×10^(19)(highest),2.14×10^(18)(lowest)and 1.37×10^(19)(average)in 2021 and forecasted to be 4.12×10^(19)(highest),2.52×10^(18)(lowest)and 1.611019(average)in *** exorbitantly high value is due to India's significant population,globalisation,inefficient wastewater efficiency,growing economy and disposable income.A lack of policies and adequate regulations further add to *** study emphasises and recommends the development of stringent policies and other well-tailored mitig

关键词： Microplastic beads Time-series forecast Policy solutions Emission estimation Personal care products

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Key features of numerical models for the FE-simulation of deep tunnel advance by the NATM

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Underground Space 2024年第1期14卷 357-376页

作者： Peter Gamnitzer Matthias Neuner Magdalena Schreter-Fleischhacker Alexander Dummer thomas Mader Stefan Smaniotto Gunter Hofstetter Unit of Strength of Materials and Structural Analysis Institute of Basic Sciences in Engineering SciencesUniversitat InnsbruckTechnikerstraβe 13Innsbruck A-6020Austria

In the present work,important aspects of time-dependent nonlinear 3D finite element(FE)models for deep tunnel advance by the New Austrian Tunneling Method(NATM),characterized by repeated sequences of excavation,securing,and idle periods,are discussed on the example of a 3D finite element model of a stretch of the Brenner Base Tunnel,which is currently constructed between Austria and *** material models are utilized for representing the surrounding rock mass and the shotcrete *** on the finite element model,strategies for the efficient implementation into a parallel distributed memory numerical code are *** are essential to achieve reasonable computation times for numerical simulations of tunneling based on large 3D FE *** particular,the implementation of the construction procedure,parallel computing and communication specific details,and efficient linear solvers for the global equation system within the incremental-iterative Newton–Raphson scheme are ***,possible extensions of the material models for rock mass and shotcrete,used in the 3D FE model,are *** concern(i)a gradient-enhanced model for transversely isotropic rock and rock mass,taking into account hardening and softening behavior and(ii)the extension of the shotcrete model to nonlinear creep and damage due to *** possible benefits of the model extensions in numerical simulations of tunneling by the NATM are discussed.

关键词： NATM Finite element model Rock Shotcrete Damage-plasticity model

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Entangled photon pair generation in an integrated SiC platform

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Light(Science & Applications) 2024年第6期13卷 1041-1046页

作者： Anouar Rahmouni Ruixuan Wang Jingwei Li Xiao Tang thomas Gerrits Oliver Slattery Qing Li Lijun Ma National Institute of Standards and Technology 100 Bureau DrGaithersburgMD20899USA Department of Electrical and Computer Engineering Carnegie Mellon UniversityPittsburghPA15213USA

Entanglement plays a vital role in quantum information *** to its unique material properties,silicon carbide recently emerged as a promising candidate for the scalable implementation of advanced quantum information processing *** date,however,only entanglement of nuclear spins has been reported in silicon carbide,while an entangled photon source,whether it is based on bulk or chip-scale technologies,has remained ***,we report the demonstration of an entangled photon source in an integrated silicon carbide platform for the first ***,strongly correlated photon pairs are efficiently generated at the telecom C-band wavelength through implementing spontaneous four-wave mixing in a compact microring resonator in the 4H-silicon-carbide-on-insulator *** maximum coincidence-to-accidental ratio exceeds 600 at a pump power of 0.17 mW,corresponding to a pair generation rate of(9±1)×10^(3) pairs/***-time entanglement is created and verified for such signal-idler photon pairs,with the two-photon interference fringes exhibiting a visibility larger than 99%.The heralded single-photon properties are also measured,with the heralded g^((2))(0)on the order of 10^(−3),demonstrating the SiC platform as a prospective fully integrated,complementary metal-oxide-semiconductor compatible single-photon source for quantum applications.

关键词： quantum coincidence mixing

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Assessment of Seasonal Rainfall Prediction in Ethiopia: Evaluating a Dynamic Recurrent Neural Network to Downscale ECMWF-SEAS5 Rainfall

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Advances in Atmospheric Sciences 2024年第11期41卷 2230-2244页

作者： Abebe KEBEDE Kirsten WARRACH-SAGI thomas SCHWITALLA Volker WULFMEYER Tesfaye ABEBE Markos WARE Hawassa University College of Agriculture P.O.Box 05HawassaEthiopia Institute of Physics and Meteorology University of HohenheimP.O.Box 70599StuttgartGermany Arba Minch University Water Institute of Technology Faculty of Meteorology and HydrologyP.O.Box 21Arba MinchEthiopia

Seasonal rainfall plays a vital role in both environmental dynamics and decision-making for rainfed agriculture in Ethiopia, a country often impacted by extreme climate events such as drought and flooding. Predicting the onset of the rainy season and providing localized rainfall forecasts for Ethiopia is challenging due to the changing spatiotemporal patterns and the country's rugged topography. The Climate Hazards Group Infra Red Precipitation with Station Data(CHIRPS), ERA5-Land total precipitation and temperature data are used from 1981–2022 to predict spatial rainfall by applying an artificial neural network(ANN). The recurrent neural network(RNN) is a nonlinear autoregressive network with exogenous input(NARX), which includes feed-forward connections and multiple network layers, employing the Levenberg Marquart algorithm. This method is applied to downscale data from the European Centre for Medium-range Weather Forecasts fifth-generation seasonal forecast system(ECMWF-SEAS5) and the Euro-Mediterranean Centre for Climate Change(CMCC) to the specific locations of rainfall stations in Ethiopia for the period 1980–2020. Across the stations, the results of NARX exhibit strong associations and reduced errors. The statistical results indicate that, except for the southwestern Ethiopian highlands, the downscaled monthly precipitation data exhibits high skill scores compared to the station records, demonstrating the effectiveness of the NARX approach for predicting local seasonal rainfall in Ethiopia's complex terrain. In addition to this spatial ANN of the summer season precipitation, temperature, as well as the combination of these two variables, show promising results.

关键词： station prediction downscaling artificial neural networks rainfall

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Rethinking Global Context in Crowd Counting

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Machine Intelligence Research 2024年第4期21卷 640-651页

作者： Guolei Sun Yun Liu thomas Probst Danda Pani Paudel Nikola Popovic Luc Van Gool Computer Vision Lab ETH ZürichZürich 8092Switzerland Institute for Infocomm Research A*STARSingapore 138632Singapore Magic Leap Zürich 8050Switzerland

This paper investigates the role of global context for crowd ***,a pure transformer is used to extract features with global information from overlapping image *** by classification,we add a context token to the input sequence,to facilitate information exchange with tokens corresponding to image patches throughout transformer *** to the fact that transformers do not explicitly model the tried-and-true channel-wise interactions,we propose a token-attention module(TAM)to recalibrate encoded features through channel-wise attention informed by the context *** that,it is adopted to predict the total person count of the image through regression-token module(RTM).Extensive experiments on various datasets,including ShanghaiTech,UCFQNRF,JHU-CROWD++and NWPU,demonstrate that the proposed context extraction techniques can significantly improve the performanceover the baselines.

关键词： Crowd counting vision transformer global context attention density map.

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Disclosing the true impact of screening endoscopy in colorectal cancer prevention

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Cancer Communications 2024年第4期44卷 504-507页

作者： thomas Heisser Carlo Senore Michael Hoffmeister Lina Jansen Hermann Brenner Division of Clinical Epidemiology and Aging Research German Cancer Research Center(DKFZ)HeidelbergBaden-WürttembergGermany Epidemiology and Screening Unit Reference Centre for Epidemiology and Cancer PreventionUniversity Hospital Cittàdella Salute e della ScienzaTurinPiedmontItaly Epidemiological Cancer Registry Baden-Württemberg German Cancer Research Center(DKFZ)HeidelbergBaden-WürttembergGermany Division of Preventive Oncology German Cancer Research Center(DKFZ)and National Center for Tumor Diseases(NCT)HeidelbergBaden-WürttembergGermany German Cancer Consortium(DKTK) German Cancer Research Center(DKFZ)HeidelbergBaden-WürttembergGermany

Preprint:https://***/10.1101/*** trials,cohort and modeling studies have consistently demonstrated a major impact of screening endoscopies on reducing colorectal cancer(CRC)inci-dence and mortality[1].Over time,CRC mortality starts to be lower in those who underwent screening compared to those who did not due to earlier detection of prevalent.

关键词： prevention endoscopy impact CRC

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A simulation study on spatial and time resolution for a cost-effective positron emission particle tracking system

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Particuology 2024年第5期88卷 312-322页

作者： Josephine Oppotsch Matthias Steinke Miriam Fritsch Fritz-Herbert Heinsius thomas Held Nikoline Hilse Viktor Scherer Ulrich Wiedner Ruhr-Universität Bochum Institut für Experimentalphysik I44801 BochumGermany Ruhr-Universität Bochum Lehrstuhl für Energieanlagen und Energieprozesstechnik44801 BochumGermany

This work is the second part of a simulation study investigating the processing of densely packed and moving granular assemblies by positron emission particle tracking (PEPT).Since medical positron emission tomography (PET) scanners commonly used for PEPT are very expensive,a PET-like detector system based on cost-effective organic plastic scintillator bars is being developed and tested for its *** this context,the spatial resolution of a resting positron source,a source moving on a freely designed model path,and a particle motion given by a discrete element method (DEM) simulation is studied using Monte Carlo simulations and the software toolkit *** not only extended the simulation and reconstruction to a moving source but also significantly improved the spatial resolution compared to previous work by adding oversampling and iteration to the reconstruction ***,in the case of a source following a trajectory developed from DEM simulations,a very good resolution of about 1 mm in all three directions and an average 3D deviation between simulated and reconstructed events of 2.3 mm could be ***,the resolution for realistic particle motion within the generic grate system (which is the test rig for further experimental studies) is well below the smallest particle *** simulation of the dependence of the reconstruction accuracy on tracer particle location revealed a nearly constant efficiency within the entire detector system,which demonstrates that boundary effects can be neglected.

关键词： Positron emission particle tracking Monte Carlo method Time-of-flight Plastic scintillators Silicon photomultipliers(SiPMs)

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