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Influence of water evaporation on elastohydrodynamic lubrication with water-containing polyalkylene glycols

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Friction 2024年第10期12卷 2370-2388页

作者： stefan HOFMANN Thomas LOHNeR Karsten STAHL Technical University of Munich School of Engineering and DesignDepartment of Mechanical EngineeringGear Research Center(FZG)Boltzmannstraße 1585748 Garching near MunichGermany

The reduction of frictional power losses in power transmitting gears takes a crucial role in the design of energy-and resource-efficient ***-containing lubricants like glycerol and polyalkylene glycols have shown great potential in achieving friction within the superlubricity regime with coefficients of friction lower than 0.01 under elastohydrodynamic ***,a bio-based production of the base stocks can lead to the development of green ***,one challenge associated with the application of water-containing lubricants to gearboxes is the evaporation of water and its impact on the lubricant *** this study,the influence of water evaporation on elastohydrodynamic friction and film thickness was investigated for three water-containing polyalkylene *** nominal water contents of 20 wt%and 40 wt%and two viscosities were *** results show that the friction increases continuously with higher evaporated water content,while the overall friction level remains low in nearly water-free states.A similar trend is observed for film thickness,where the strong increase in viscosity results in a notable increase in film ***,the sensitivity of friction and film thickness to water evaporation is low for small amounts of evaporated *** allows generous thresholds for permissible variations in water content.

关键词： friction superlubricity aqueous lubrication elastohydrodynamic lubrication(eHL) evaporation polyalkylene glycol

Transfer learning applications for autoencoder-based anomaly detection in wind turbines

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energy and AI 2024年第3期17卷 1-10页

作者： Cyriana M.A.Roelofs Christian Gück stefan Faulstich Fraunhofer Iee Joseph-Beuys-Straße 834117 KasselGermany

Anomaly detection in wind turbines typically involves using normal behaviour models to detect faults *** behaviour models are often implemented through the use of neural networks,of which autoencoders are particularly popular in this ***,training autoencoder models for each turbine is time-consuming and resource ***,transfer learning becomes essential for wind turbines with limited data or applications with limited computational *** study examines how cross-turbine transfer learning can be applied to autoencoder-based anomaly ***,autoencoders are combined with constant thresholds for the reconstruction error to determine if input data contains an *** models are initially trained on one year’s worth of data from one or more source wind *** are then fine-tuned using small amounts of data from the target wind *** methods for fine-tuning are investigated:adjusting the entire autoencoder,only the decoder,or only the threshold of the *** performance of the transfer learning models is compared to baseline models that were trained on one year’s worth of data from the target wind *** results of the tests conducted in this study indicate that models trained on data of multiple wind turbines do not improve the anomaly detection capability compared to models trained on data of one source wind *** addition,modifying the model’s threshold can lead to comparable or even superior performance compared to the baseline,whereas fine-tuning the decoder or autoencoder further enhances the models’performance.

关键词： Condition monitoring Transfer learning Autoencoder Anomaly detecti on Wind turbines Fault detection

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

Fetal lung growth predicts the risk for early-life respiratory infections and childhood asthma

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World Journal of Pediatrics 2024年第5期20卷 481-495页

作者： Dimitra e.Zazara Olympia Giannou Steven Schepanski Mirja Pagenkemper Anastasios D.Giannou Maike Pincus Ioannis Belios stefan Bonn Ania C.Muntau Kurt Hecher Anke Diemert Petra Clara Arck Division for experimental Feto-Maternal Medicine Department of Obstetrics and Fetal MedicineUniversity Medical Center Hamburg-Eppendorf(UKE)Martinistraße 5220251HamburgGermany University Children’s Hospital UKEHamburgGermany Computer engineering and Informatics Department Polytechnic SchoolUniversity of PatrasPatrasGreece Institute of Developmental Neurophysiology Center for Molecular Neurobiology Hamburg(ZMNH)UKEHamburgGermany Department of Obstetrics and Fetal Medicine UKEHamburgGermany Department of General Visceral and Thoracic SurgeryUKEHamburgGermany Section of Molecular Immunology and Gastroenterology Ⅰ.Department of MedicineUKEHamburgGermany Pediatrics and Pediatric Pneumology Practice BerlinGermany Institute of Medical Systems Biology ZMNHUKEHamburgGermany Hamburg Center for Translational Immunology UKEHamburgGermany

Background early-life respiratory infections and asthma are major health burdens during *** predicting an increased risk for early-life respiratory diseases are ***,we identified the predictive value of ultrasound-monitored fetal lung growth for the risk of early-life respiratory infections and *** Fetal lung size was serially assessed at standardized time points by transabdominal ultrasound in pregnant women participating in a pregnancy *** between fetal lung growth and respiratory infections in infancy or early-onset asthma at five years were ***-learning models relying on extreme gradient boosting regressor or classifier algorithms were developed to predict respiratory infection or asthma risk based on fetal lung *** model development and validation,study participants were randomly divided into a training and a testing group,respectively,by the employed *** enhanced fetal lung growth throughout pregnancy predicted a lower early-life respiratory infection *** sex was associated with a higher risk for respiratory infections in *** lung growth could also predict the risk of asthma at five years of *** designed three machine-learning models to predict the risk and number of infections in infancy as well as the risk of early-onset *** models’R2 values were 0.92,0.90 and 0.93,respectively,underscoring a high accuracy and agreement between the actual and predicted *** variables included known risk factors and novel predictors,such as ultrasound-monitored fetal lung *** Sonographic monitoring of fetal lung growth allows to predict the risk for early-life respiratory infections and asthma.

关键词： Asthma Child risk early-life respiratory infections Prenatal lung development Sexual dimorphism

eVA NeXUS-Phaco performance study

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International Journal of Ophthalmology(english edition) 2024年第8期17卷 1447-1452页

作者： Lukas Feldhaus Andreas Ohlmann stefan Kassumeh Siegfried Priglinger Wolfgang Mayer Department of Ophthalmology University HospitalLudwig-Maximilians-University MunichMunich 80336Germany

AIM:To investigate a novel phacoemulsification system“eVA NeXUS”(D.O.R.C.,Dutch Opthalmic Research Center)in comparison to the existing system“eVA”in clinical *** to compare both phacoemulsification systems in terms of efficiency,safety and postoperative inflammatory ***:In this study standardized cataract surgery was performed on both eyes of the study participant,using the“eVA system”(control group,n=20)on one eye and the“eVA NeXUS system”(intervention group,n=20)on the other *** patients with cataract LOCS Grading 1-3 and no accompanying eye diseases were included in this study.A total of 20 patients were included in this study,with each treatment arm including 20 *** surgery a 0.1 mL aqueous humor sample was collected 1min after phacoemulsification to measure the total prostaglanin e2 concentrations using an enzyme-linked immunosorbent *** endothelial cell count,visual and refractive outcomes,and anterior chamber flare were evaluated preoperatively,and 1d,1wk,and 3mo ***:There were no statistically significant differences between both groups regarding intraoperative safety parameters including effective phacoemulsification time(P=0.904),balanced saline solution flow(P=0.701)and total surgery time(P=0.565).Postoperative prostaglandin e2 levels,anterior chamber flare as well as endothelial cell loss tended to be lower in the NeXUS-Group,however not being statistically significant(P=0.718;0.164;0.486).Both systems provided similar clinical outcomes,regarding best corrected visual acuity and refractive parameters,showing no statistically significant differences between both ***:Both systems show a high level of safety and efficency with similar results in terms of safety parameters including postoperative inflammatory activity and endothelial cell loss as well as visual and refractive *** statistically not significant,the eVA NeXUS system tends to cause less postoperative inflammatio

关键词： cataract surgery phacoemulsification fluidics instrument

Promoting the production of challenging proteins via induced expression in CHO cells and modified cell-free lysates harboring T7 RNA polymerase and mutant eIF2α

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Synthetic and Systems Biotechnology 2024年第3期9卷 416-424页

作者： Jeffrey L.Schloßhauer Lena Tholen Alexander Korner stefan Kubick Sofia Chatzopoulou Anja Honow Anne Zemella Fraunhofer Project Group PZ-Syn of the Fraunhofer Institute for Cell Therapy and Immunology-IZI Branch Bioanalytics and Bioprocesses-IZI-BBAm MühlenbergPotsdamGermany Fraunhofer Institute for Cell Therapy and Immunology-IZI Branch Bioanalytics and Bioprocesses-IZI-BBAm MühlenbergPotsdamGermany Faculty of Health Sciences Joint Faculty of the Brandenburg University of Technology Cottbus-SenftenbergThe Brandenburg Medical School Theodor FontaneUniversity of PotsdamPotsdamGermany Institute for Chemistry and Biochemistry Laboratory of Protein BiochemistryFreie Universitat BerlinThielallee 6314195BerlinGermany Institute of Biotechnology Technische Universit¨at BerlinStraße des 17.Juni 13510623BerlinGermany New/era/mabs GmbH August-Bebel-Str.8914482PotsdamGermany

Chinese hamster ovary(CHO)cells are crucial in biopharmaceutical production due to their scalability and capacity for human-like post-translational ***,toxic proteins and membrane proteins are often difficult-to-express in living ***,cell-free protein synthesis can be *** study explores innovative strategies for enhancing the production of challenging proteins through the modification of CHO cells by investigating both,cell-based and cell-free approaches.A major result in our study involves the integration of a mutant eIF2 translation initiation factor and T7 RNA polymerase into CHO cell lysates for cell-free protein *** resulted in elevated yields,while eliminating the necessity for exogenous additions during cell-free production,thereby substantially enhancing ***,we explore the potential of the Rosa26 genomic site for the integration of T7 RNA polymerase and cell-based tetracycline-controlled protein *** findings provide promising advancements in bioproduction technologies,offering flexibility to switch between cell-free and cell-based protein production as needed.

关键词： Inducible expression CHO cells Cell-free protein synthesis CRISPR T7 RNA polymerase eIF2 Rosa26

Towards engineering a portable platform for laparoscopic pre-training in virtual reality with haptic feedback

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虚拟现实与智能硬件（中英文） 2024年第2期6卷 83-99页

作者： Hans-Georg eNKLeR Wolfgang KUNeRT stefan PFeFFeR Kai-Jonas BOCK Steffen AXT Jonas JOHANNINK Christoph ReICH Furtwangen University 78120 FurtwangenGermany University Hospital and Faculty of Medicine Tuebingen 72076 TuebingenGermany

Background Laparoscopic surgery is a surgical technique in which special instruments are inserted through small incision holes inside the *** some time,efforts have been made to improve surgical pre training through practical exercises on abstracted and reduced *** The authors strive for a portable,easy to use and cost-effective Virtual Reality-based(VR)laparoscopic pre-training platform and therefore address the question of how such a system has to be designed to achieve the quality of today's gold standard using real tissue *** VR controllers are limited regarding haptic *** haptic feedback is necessary or at least beneficial for laparoscopic surgery training,the platform to be developed consists of a newly designed prototype laparoscopic VR controller with haptic feedback,a commercially available head-mounted display,a VR environment for simulating a laparoscopic surgery,and a training *** To take full advantage of benefits such as repeatability and cost-effectiveness of VR-based training,the system shall not require a tissue sample for haptic *** is currently calculated and visually displayed to the user in the VR *** the prototype controller,a first axis was provided with perceptible feedback for test *** of the prototype VR controllers can be combined to simulate a typical both-handed use case,e.g.,laparoscopic suturing.A Unity based VR prototype allows the execution of simple standard *** The first prototype enables full operation of a virtual laparoscopic instrument in *** addition,the simulation can compute simple interaction *** challenges lie in a realistic real-time tissue simulation and calculation of forces for the haptic *** weaknesses were identified in the first hardware prototype,which will be improved in subsequent *** degrees of freedom of the controller are to be provided with haptic *** make forces t

关键词： Laparoscopic surgery Training Virtual reality Controller Haptic feedback Kinesthetic skills

Spatiotemporal drivers of Nature's contributions to people:A countylevel study

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environmental Science and ecotechnology 2024年第4期20卷 323-332页

作者： Wei Jiang Bojie Fu Zhongguo Shu Yihe Lv Guangyao Gao Xiaoming Feng stefan Schüler Xing Wu Cong Wang State Key Laboratory of Urban and Regional ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesNo.18 Shuangqing Road100085BeijingChina Functional Agrobiodiversity Georg-August-Universit€at G€ottingenGrisebachstraße 637077G€ottingenGermany

Nature's contributions to people(NCP)encompass both the beneficial and detrimental effects of living nature on human quality of life,including regulatory,material,and non-material ***,vital NCPs have been deteriorating,accelerated by changes in both natural and anthropogenic drivers over recent *** the often inevitable trade-offs between NCPs due to their spatially and temporally uneven distributions,few studies have quantitatively assessed the impacts of different drivers on the spatial and temporal changes in multiple NCPs and their *** we evaluate the effects of precipitation,temperature,population,gross domestic product,vegetation restoration,and urban expansion on four key regulatory NCPs-habitat maintenance,climate regulation,water quantity regulation,and soil protection-in Nei Mongol at the county *** observe increasing trends in climate regulation and soil protection from 2000 to 2019,contrasted with declining trends in habitat maintenance and water quantity *** have identified the dominant positive and negative drivers influencing each NCP across individual counties,finding that natural drivers predominantly overpowered anthropogenic ***,we discover significant spatial disparities in the tradeoff or synergy relationships between NCPs across the *** findings illustrate how the impacts of various drivers on NCPs and their interrelationships can be quantitatively evaluated,offering significant potential for application in various spatial *** an understanding of trade-offs and scale effects,these insights are expected to support and inform policymaking at both county and provincial levels.

关键词： Potential regulating contributions Natural and anthropogenic drivers Path analysis Trade-off or synergy relationship China

exploring fs-laser irradiation damage subthreshold behavior of dielectric mirrors via electrical measurements

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High Power Laser Science and engineering 2024年第2期12卷 24-32页

作者： Petrisor Gabriel Bleotu Radu Udrea Alice Dumitru Olivier Uteza Maria-Diana Mihai Dan Gh Matei Daniel Ursescu stefan Irimiciuc Valentin Craciun extreme Light Infrastructure-Nuclear Physics(eLI-NP) Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering(IFIN-HH)MagureleRomania Doctoral School of Physics University of BucharestMagureleRomania LULI-CNRS CEAUniversite SorbonneEcole PolytechniqueInstitut Polytechnique de ParisPalaiseau CEDEXFrance Apel Laser IlfovRomania Aix-Marseille University CNRSLP3 UMR 7341MarseilleFrance Horia Hulubei National Institute for R&D in Physics and Nuclear engineering(IFIN-HH) MagureleRomania University Politehnica of Bucharest BucharestRomania National Institute for Lasers Plasma and Radiation Physics MagureleRomania

With ultrafast laser systems reaching presently 10 PW peak power or operating at high repetition rates,research towards ensuring the long-term,trouble-free performance of all laser-exposed optical components is *** work is focused on providing insight into the optical material behavior at fluences below the standardized laser-induced damage threshold(LIDT)value by implementing a simultaneous dual analysis of surface emitted particles using a Langmuir probe(LP)and the target current(TC).HfO_(2) and ZrO_(2) thin films deposited on fused silica substrates by pulsed laser deposition at various O_(2) pressures for defect and stoichiometry control were irradiated by Gaussian,ultrashort laser pulses(800 nm,10 Hz,70 fs)in a wide range of *** TC and LP collected signals were in good agreement with the existing theoretical description of laser–matter interaction at an ultrashort time *** approach for an in situ LIDT monitoring system provides measurable signals for below-threshold irradiation conditions that indicate the endurance limit of the optical surfaces in the single-shot energy scanning *** LIDT value extracted from the LP-TC system is in line with the multipulse statistical analysis done with ISO 21254-2:2011(e).The implementation of the LP and TC as on-shot diagnostic tools for optical components will have a significant impact on the reliability of next-generation ultrafast and high-power laser systems.

关键词： HfO_(2) in situ detection Langmuir probe laser-induced damage threshold target current ZrO_(2)