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A maintenance Service Improvement Approach Based on Queue Networks: Application

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Open Journal of Applied Sciences 2024年第2期14卷 425-440页

作者： Aslain Brisco Ngnassi Djami wolfgang Nzié Boukar Ousman Joseph Nkongho Anyi Ulrich Ngnassi Nguelcheu Department of Fundamental Sciences and Techniques of Engineer Chemical Engineering and Mineral Industries School University of Ngaoundere Ngaoundere Cameroon Laboratory of mechanics Materials and Photonics National School of Agro-Industrial Sciences University of Ngaoundere Ngaoundere Cameroon Department of Electrical Engineering Energy and Automation National School of Agro-Industrial Sciences University of Ngaoundere Ngaoundere Cameroon Laboratory E3m Faculty of Industrial Engineering University of Douala Douala Cameroon Department of Physics Faculty of Science University of Ngaoundere Ngaoundere Cameroon

The quest to increase the performance of production systems that have become complex leads to the transfer to the maintenance function of the responsibility of guaranteeing the availability of such systems. Also, we will never stop saying that maintenance must integrate into all of the company’s initiatives, to affirm its role, which is to ensure greater availability and sustainability of the means of production. The objective of this paper is to evaluate the reliability and availability of a system without knowing the distribution law of the operating times. Among the methods for evaluating dependability criteria (Fault Trees, Petri Nets, etc.), we are interested in queues that have the advantage of taking into account functional dependencies, thus allowing a quantified optimization of maintenance. Indeed, queues make it possible to model parallel or sequential processes, implementing operations taking place at the same time or one after the other, meeting the needs of modeling production systems. The main result of this paper is the study of the influence of availability on the reliability of a multi-state production system.

关键词： markov Chains Queues Availability Reliability maintenance

Hot electron electrochemistry at silver activated by femtosecond laser pulses

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Opto-Electronic Advances 2023年第6期6卷 31-36页

作者： Oskar Armbruster Hannes Pöhl wolfgang Kautek University of Natural Resources and Life Sciences ViennaDepartment of BionanosciencesMuthgasse 111190 ViennaAustria University of Vienna Department of Physical ChemistryWähringer Straße 421090 ViennaAustria

A silver microelectrode with a diameter of 30μm in an aqueous K_(2)SO_(4) electrolyte was irradiated with 55 fs and 213 fs laser *** caused the emission of electrons which transiently charged the electrochemical double *** two applied pulse durations were significantly shorter than the electron-phonon relaxation *** laser pulse durations had negligible impact on the emitted charge,which is incompatible with multiphoton *** the other hand,the ob-served dependence of emitted charge on laser fluence and electrode potential supports the thermionic emission mechanism.

关键词： hot electron emission femtosecond laser laser electrochemistry silver electrode

Classifying handedness in chiral nanomaterials using label error robust deep learning

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npj Computational materials 2022年第1期8卷 1417-1423页

作者： C.K.Groschner Alexander J.Pattison Assaf Ben-moshe A.Paul Alivisatos wolfgang Theis m.C.Scott Department of materials Science and Engineering UC BerkeleyBerkeleyCAUSA School of Physics and Astronomy University of BirminghamBirminghamUK Department of Chemistry University of CaliforniaBerkeleyBerkeleyCAUSA materials Sciences Division Lawrence Berkeley National LaboratoryBerkeleyCAUSA molecular Foundry Lawrence Berkeley National LaboratoryBerkeleyBerkeleyCAUSA

High-throughput scanning electron microscopy(SEm)coupled with classification using neural networks is an ideal method to determine the morphological handedness of large populations of chiral *** labeling removes the time-consuming manual labeling of training data,but introduces label error,and subsequently classification error in the trained neural ***,we evaluate methods to minimize classification error when training from automated labels of SEm datasets of chiral Tellurium *** the mirror relationship between images of opposite handed particles,we artificially create populations of varying label *** analyze the impact of label error rate and training method on the classification error of neural networks on an ideal dataset and on a practical *** the three training methods considered,we find that a pretraining approach yields the most accurate results across label error rates on ideal datasets,where size and other morphological variables are held constant,but that a co-teaching approach performs the best in practical application.

关键词： error chiral remove

In-silico synthesis of lowest-pressure high-T_(c) ternary superhydrides

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npj Computational materials 2022年第1期8卷 1119-1125页

作者： Roman Lucrezi Simone Di Cataldo wolfgang von der Linden Lilia Boeri Christoph Heil Institute of Theoretical and Computational Physics Graz University of TechnologyNAWI Graz8010GrazAustria Dipartimento di Fisica Sapienza Universitàdi Roma00185RomeItaly Enrico Fermi Research Center Via Panisperna 89 A00184RomeItaly

We report the theoretical prediction of two high-performing hydride superconductors BaSiH_(8)and SrSiH_(8).They are thermodynamically stable above pressures of 130 and 174 GPa,respectively,and metastable below *** anharmonic phonon calculations,we determine the minimum pressures of dynamical stability to be around 3 GPa for BaSiH8 and 27 GPa for SrSiH_(8),and using the fully anisotropic migdal-Eliashberg theory,we predict Tc’s around 71 and 126 K,*** also introduce a method to estimate the lowest pressure of synthesis,based on the calculation of the enthalpy barriers protecting the BaSiH_(8)Fm3¯m structure from decomposition at various *** kinetic pressure threshold is sensibly higher than the one based on dynamic stability,but gives a much more rigorous limit for synthesizability.

关键词： synthesis stability high

Exogenous nitrogen input skews estimates of microbial nitrogen use efficiency by ecoenzymatic stoichiometry

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Ecological Processes 2023年第3期12卷 189-195页

作者： Lifei Sun Daryl L.moorhead Yongxing Cui wolfgang Wanek Shuailin Li Chao Wang CAS Key Laboratory of Forest Ecology and management Institute of Applied Ecology Chinese Academy of Sciences Department of Environmental Sciences University of Toledo Sino-French Institute for Earth System Science College of Urban and Environmental Sciences Peking University Division of Terrestrial Ecosystem Research Center of Microbiology and Environmental Systems Science University of Vienna

Background Ecoenzymatic stoichiometry models（EEST） are often used to evaluate microbial nutrient use efficiency, but the validity of these models under exogenous nitrogen（N） input has never been clarified. Here, we investigated the effects of long-term N addition（as urea） on microbial N use efficiency（NUE）, compared EEST and18O-labeling methods for determining NUE, and evaluated EEST's theoretical assumption that the ratios of standard ecoenzymatic activities balance resource availability with microbial *** We found that NUE estimated by EEST ranged from 0.94 to 0.98. In contrast, estimates of NUE by the18O-labeling method ranged from 0.07 to 0.30. The large differences in NUE values estimated by the two methods may be because the sum of β-N-acetylglucosaminidase and leucine aminopeptidase activities in the EEST model was not limited to microbial N acquisition under exogenous N inputs, resulting in an overestimation of microbial NUE by EEST. In addition, the acquisition of carbon by N-acquiring enzymes also likely interferes with the evaluation of NUE by *** Our results demonstrate that caution must be exercised when using EEST to evaluate NUE under exogenous N inputs that may skew standard enzyme assays.

关键词： Extracellular enzyme Resource allocation Nitrogen addition microbial metabolism limitation Isotope labeling

Effects of Bentonite,Hydrogel and Biochar Amendments on Soil Hydraulic Properties from Saturation to Oven Dryness

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Pedosphere 2019年第5期29卷 598-607页

作者： Osama m0HAWESH wolfgang DURNER Department of Plant Production Faculty of AgricultureMutah UniversityKarak 61710 (Jordan) Division of Environmental Science and Technology Graduate School of AgricultureKyoto UniversityKyoto 6110011 (Japan) Institute of Geoecology Technical University of BraunschweigLanger Kamp 19cBraunschweig 38106 (Germany)

Effects of hydrogel, bentonite, and biochar as soil amendments on soil hydraulic properties and improving water availability from saturation to oven dryness were investigated. Soils were mixed with hydrogel (0.10%, 0.25%, and 0.50%), bentonite (0.5%, 1.0%, and 2.5%), and biochar (1.0%, 2.5%, and 5.0%) as soil amendments (weight:weight). Three methods (extended multistep outflow (XmSO), evaporation (EVA), and WP4 dewpoint potentiometer) were used to measure soil hydraulic properties from saturation to oven dryness. The cumulative XmSO results were more uniform across all the applied pressure steps for the amended soils. The EVA exhibited a shorter linear decrease during the first evaporation stage and a lower evaporation rate during the second evaporation stage. The WP4 results also exhibited that soil amendments increased the soil water content of the amended soils at low matric potentials. The results of soil water retention curves revealed that the unamended soil retained less water at any matric potential compared to the amended soils. Soil hydraulic conductivity decreased with increasing amount of soil amendments. The saturated hydraulic conductivity was higher for the unamended soil than the soils amended w计h 2.5% bentonite, 0.50% hydrogel, and 5.0% biochar by 11, 3, and 18 times, respectively. These results suggested that soil amendments improved soil water retentivity, which confirmed the appropriateness of these soil amendments for potential use in sandy soil improvements. However, field experiments and economical perception studies should be considered for further investigation.

关键词： evaporation extended multistep outflow soil amendment soil matric potential soil moisture soil water retentivity water availability WP4 dewpoint potentiometer

Overlap of concurrent extrahepatic autoimmune diseases is associated with milder disease severity of newly diagnosed autoimmune hepatitis

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Hepatobiliary & Pancreatic Diseases International 2021年第1期20卷 21-27页

作者： Tobias mühling Helmut Rohrbach wolfgang Schepp Felix Gundling Department of Gastroenterology Internal Medicine ⅡUniversity of WürzburgWürzburgGermany Department of Pathology Academic Teaching Hospital BogenhausenTechnical University of MunichMunich 81925Germany Department of Gastroenterology Hepatology and Gastrointestinal OncologyAcademic Teaching Hospital BogenhausenTechnical University of MunichMunich 81925Germany Department of Internal medicine Division of GastroenterologyGastrointestinal Oncology and DiabetologyKemperhof KoblenzKoblenzGermany

Background:Concurrent extrahepatic autoimmune disorders(CEHAID)are frequently observed in autoimmune hepatitis(AIH).It is not clear whether there is any prognostic significance of CEHAID on *** aim of this study was to examine the prognostic impact of CEHAID and the correlation with the disease severity of ***:This study included 65 hospitalized subjects who fulfilled the accepted criteria for AIH during an 8-year period(2009–2016).All records were manually screened for presence of associated autoimmune *** severity of AIH was assessed by liver laboratory tests including the ratio of aspartate aminotransferase to alanine aminotransferase(AST/ALT)and liver ***:Among the enrolled patients,52(80%)were female(median age 61 years,IQR 45–75).Fifty-six(86.2%)were classified as type-1 *** 26(40%)patients at least one additional extrahepatic autoimmune disease was ***-four subjects were referred to our hospital because of acute presentation of AIH(supposed by an acute elevation of hepatic enzymes)for subsequent liver biopsy resulting in initial diagnosis of *** group was stratified into 3 subgroups:(A)AIH alone(n=14);(B)overlap with primary biliary cirrhosis(PBC)/primary sclerosing cholangitis(PSC)(n=11);and(C)with CEHAID(n=9).AST/ALT ratio was the lowest in subgroup C(median 0.64,IQR 0.51–0.94;P=0.023),compared to subgroup A(median 0.91,IQR 0.66–1.10)and subgroup B(median 1.10,IQR 0.89–1.36).Patients with AIH alone showed a trend to the highest grade of fibrosis(mean 2.3;95%CI:1.5–3.0)with no statistical significance compared to subjects with CEHAID(lowest grade of fibrosis;mean 1.5;95%CI:0.2–2.8;P=0.380)whereas the ongoing inflammation was ***:AST/ALT ratio and extent of fibrosis were lower in subjects with AIH and CEHAID,compared to subjects with only ***,the occurrence of CEHAID might be a predictor for lower disease severity of newly diagnosed acute onset AIH,possibly caused by an e

关键词： Autoimmune hepatitis Concurrent extrahepatic autoimmune disease Serum aminotransferase activities

Double Layer Composite Electrode Strategy for Efficient Perovskite Solar Cells with Excellent Reverse-Bias Stability

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Nano-micro Letters 2023年第1期15卷 225-235页

作者： Chaofan Jiang Junjie Zhou Hang Li Liguo Tan minghao Li wolfgang Tress Liming Ding michael Grätzel Chenyi Yi State Key Laboratory of Power System Department of Electrical EngineeringTsinghua UniversityBeijing 100084People’s Republic of China Institute of Computational Physics(ICP) ZHAW School of EngineeringWildbachstr.218400 WinterthurSwitzerland Center for Excellence in Nanoscience(CAS) Key Laboratory of Nanosystem and Hierarchical Fabrication(CAS)National Center for Nanoscience and TechnologyBeijing 100190People’s Republic of China Laboratory of Photonics and Interfaces Department of Chemistry and Chemical EngineeringSwiss Federal Institute of Technology Lausanne1015 LausanneSwitzerland

Perovskite solar cells(PSCs)have become the represent-atives of next generation of photovoltaics;nevertheless,their stability is insufficient for large scale deployment,particularly the reverse bias ***,we propose a transparent conducting oxide(TCO)and low-cost metal composite electrode to improve the stability of PSCs without sacrificing the *** TCO can block ion migrations and chemical reactions between the metal and perovskite,while the metal greatly enhances the conductivity of the composite *** a result,composite electrode-PSCs achieved a power conversion efficiency(PCE)of 23.7%(certified 23.2%)and exhibited excellent stability,maintaining 95%of the initial PCE when applying a reverse bias of 4.0 V for 60 s and over 92%of the initial PCE after 1000 h continuous light *** composite electrode strategy can be extended to different combinations of TCOs and *** opens a new avenue for improving the stability of PSCs.

关键词： Composite electrode Perovskite solar cells Stability Reverse bias Characterization

Effects of Saccharomyces cerevisiae or boulardii yeasts on acute stress induced intestinal dysmotility

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World Journal of Gastroenterology 2016年第48期22卷 10532-10544页

作者： Christine West Andrew m Stanisz Annette Wong wolfgang A Kunze mcmaster Brain-Body Institute St. Joseph’s Healthcare Department of Biology McM aster University Department of Psychiatry and Behavioural Neurosciences Mc Master University

AIm To investigate the capacity of Saccharomyces cerevisiae(S. cerevisiae) and Saccharomyces boulardii(S. boulardii) yeasts to reverse or to treat acute stress-related intestinal *** Adult Swiss Webster mice were stressed for 1 h in a wire-mesh restraint to induce symptoms of intestinal dysmotility and were subsequently killed by cervical dislocation. Jejunal and colon tissue were excised and placed within a tissue perfusion bath in which S. cerevisiae, S. boulardii, or their supernatants were administered into the lumen. Video recordings of contractility and gut diameter changes were converted to spatiotemporal maps and the velocity, frequency, and amplitude of propagating contractile clusters(PCC) were measured. motility pre- and post-treatment was compared between stressed animals and unstressed controls. RESULTS S. boulardii and S. cerevisiae helped to mediate the effects of stress on the small and large intestine. Restraint stress reduced jejunal transit velocity(mm/s)from 2.635 ± 0.316 to 1.644 ± 0.238, P m 0.032 ± 0.008 to 0.016 ± 0.005, P mm/s) from 0.864 ± 0.183 to 1.432 ± 0.329, P minal application of S. boulardii helped to restore jejunal and colonic velocity towards the unstressed controls; 1.833 ± 0.688 to 2.627 ± 0.664, P most apparent in the jejunum. S. cerevisiae increased PCC velocity in the stressed jejunum from 1.763 ± 0.397 to 2.017 ± 0.48, P = 0.0031 and PCC frequency from 0.016 ± 0.009 to 0.027 ± 0.007, P m 1.647 ± 0.187 to 1.038 ± 0.222, P motility to unstressed values in similar capacity. CONCLUSION The

关键词： Intestine Saccharomyces cerevisiae Saccharomyces boulardii Restraint stress motility