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Chemistry and particle size distribution of respirable coal dust in underground mines in Central Eastern Europe

International Journal of Coal Science & Technology 2022年第1期9卷 200-216页

作者： Pedro Trechera xavier Querol Robert Lah Diane Johnson Aleksander Wrana Ben Williamson Teresa Moreno Instituto de Diagnostico Ambiental Y Estudios del Agua Consejo Superior de Investigaciones Cientificas(IDAEACSIC)C/Jordi Girona 18‑2608034 BarcelonaSpain Department of Natural Resources and Environment Industrial and TIC Engineering(EMIT-UPC)08242 ManresaSpain Premogovnik Velenje d.d Partizanskacesta 783320 VelenjeSlovenia Camborne School of Mines University of ExeterPenrynCornwall TR109FEUK Department of Extraction Technology and Mining Support Central Mining Institute(GIG)40‑166 KatowicePlacGwarkow 1Poland

Despite international efforts to limit worker exposure to coal dust,it continues to impact the health of thousands of miners across *** coal dust has been studied to improve risk models and its control to protect *** size distribution analyses shows that using spraying systems to suppress airborne dusts can reduce particulate matter concentrations and that coals with higher ash yields produce finer *** are marked chemical differences between parent coals and relatively coarse deposited dusts(up to _(500)μm,DD_(500)).Enrichments in Ca,K,Ba,Se,Pb,Cr,Mo,Ni and especially As,Sn,Cu,Zn and Sb in the finest respirable dust fractions could originate from:(i)mechanical machinery wear;(ii)variations in coal mineralogy;(iii)coal fly ash used in shotcrete,and carbonates used to reduce the risk of *** enrichments in Ca in mine dusts are attributed to the use of such concrete,and elevated K to raised levels of phyllosilicate mineral *** concentrations are higher in the parent coal than in the DD_(500),probably due to relatively lower levels of organic *** concentrations of all elements observed in this study remained below occupational exposure limits.

关键词： Coal dust Deposited dust Respirable dust Particle size distribution Dust chemistry PM10 coal dust exposure

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Coupled models may help clarify the drivers of observed icesheet melt season shift:comments on Liang et al.(2023)

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National Science Review 2023年第9期10卷 247-247页

作者： xavier Fettweis Department of Geography University of Liège

A new machine-learning-based algorithm deriving melt extent from satellite data [1] has shown that the timing of the melt season over Antarctica has shifted between 1978 and *** later onset and end of the melt season result from complex interactions between the general circulation around Antarctica and sea-ice cover impacting heat exchanges between atmosphere and ocean around the ice sheet.

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Convenient model of hard tissue simulation for dental radiographic research and instruction

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World Journal of Methodology 2024年第1期14卷 80-86页

作者： Etiene Andrade Munhoz Claudio Roberto Gaiao xavier Roberto Ponce Salles Ana Lúcia Alvares Capelozza Augusto Vanni Bodanezi Department of Dentistry Health Science CentreFederal University of Santa CatarinaFlorianopolis 88040-379Brazil Department of Stomatology Radiology and Oral SurgerySchool of DentistryUniversity of São PauloBauru 17012-901Brazil

BACKGROUND The authors describe a technique for building an alternative jawbone phantom using dental gypsum and rice for research and dental radiology *** To investigate the potential of an alternative phantom to simulate the trabecular bone aspect of the human maxilla in periapical *** Half-maxillary phantoms built from gypsum-ground rice were exposed to X-rays,and the resulting images(experimental group)were compared to standardized radiographic images produced from dry human maxillary bone(control group)(n=7).The images were blindly assessed according to strict criteria by three examiners for the usual trabecular aspects of the surrounding bone,and significant differences between groups and in assessment reliability were compared using Fisher’s exact and kappa tests(α=0.05).RESULTS The differences in the trabecular aspects between groups were not statistically *** addition,interobserver agreement among observers was 0.43 and 0.51 for the control and experimental groups,respectively,whereas intraobserver agreement was 0.71 and 0.73,*** The tested phantom seemed to demonstrate potential for trabecular bone image Munhoz EA et *** of hard tissue simulation for dental radiography WJM https://*** 2 March 20,2024 Volume 14 Issue 1 simulation on maxillary periapical radiographs.

关键词： Phantom Radiology Education Endodontic treatment Bone trabecular

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Determining indoor air quality and identifying the origin of odour episodes in indoor environments

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Journal of Environmental Sciences 2009年第3期21卷 333-339页

作者： Eva Gallego xavier Roca Jose Francisco Perales xavier Guardino Environmental Centre Laboratory Polytechnic University of Catalonia (LCMA-UPC) Avda Diagonal 647 E 08028 Barcelona Spain National Centre of Work Conditions (INSHT) Dulcet 2-10 E 08034 Barcelona Spain

A methodology for identifying volatile organic compounds （VOCs） and determining air quality of indoor air has been developed. The air samples are collected using pump samplers by the inhabitants when they perceive odorous and/or discomfort episodes. Glass multi-sorbent tubes are connected to the pump samplers for the retention of VOC. The analysis is performed by automatic thermal desorption （ATD） coupled with gas chromatography-mass spectrometry （GC/MS）. This methodology can be applied in cases of sick building syndrome （SBS） evaluation, in which building occupants experience a series of varied symptoms that appear to be linked to time spent in the building. Chemical pollutants concentrations （e.g., VOC） have been described to contribute to SBS. To exemplify the methodology, a qualitative determination and an evaluation of existing VOC were performed in a dwelling where the occupants experienced the SBS symptoms. Higher total VOC （TVOC） levels were detected during episodes in indoor air （1.33 ±1.53 mg/m^3） compared to outdoor air （0.71± 0.46 mg/m^3）. The concentrations of individual VOCs, such as ethanol, acetone, isopropanol, 1-butanol, acetic acid, acetonitrile and 1-methoxy-2-propanol, were also higher than the expected for a standard dwelling. The external source of VOC was found to be an undeclared activity of storage and manipulation of solvents located at the bottom of a contiguous building.

关键词： indoor air thermal desorption TVOC VOC sick building syndrome

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Isoperimetric,Sobolev,and Eigenvalue Inequalities via the Alexandroff-Bakelman-Pucci Method:A Survey

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Chinese Annals of Mathematics,Series B 2017年第1期38卷 201-214页

作者： xavier CABRe Universitat Politecnica de Catalunya Departament de MatemktiquesDiagonal 64708028 BarcelonaSpain ICREA Pg.Lluis Companys 2308010 BarcelonaSpain.

This paper presents the proof of several inequalities by using the technique introduced by Alexandroff, Bakelman, and Pucci to establish their ABP estimate. First,the author gives a new and simple proof of a lower bound of Berestycki, Nirenberg, and Varadhan concerning the principal eigenvalue of an elliptic operator with bounded measurable coefficients. The rest of the paper is a survey on the proofs of several isoperimetric and Sobolev inequalities using the ABP technique. This includes new proofs of the classical isoperimetric inequality, the Wulff isoperimetric inequality, and the Lions-Pacella isoperimetric inequality in convex cones. For this last inequality, the new proof was recently found by the author, xavier Ros-Oton, and Joaquim Serra in a work where new Sobolev inequalities with weights came up by studying an open question raised by Haim Brezis.

关键词： Isoperimetric inequalities Principal eigenvalue Wulff shapes ABP estimate

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Rare case of ascites several years after liver transplantation

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Gastroenterology Report 2022年第1期10卷 677-679页

作者： Liesbeth Deroo Anne Hoorens xavier Verhelst Helena Degroote Hans Van Vlierberghe Anja Geerts Department of Gastroenterology and Hepatology Ghent University HospitalGhentBelgium Department of Pathology Ghent University HospitalGhentBelgium

Case report A 67-year-old male patient with a history of liver transplantation presented with complaints of progressive abdominal *** had a history of alcoholic cirrhosis complicated by hepatocellular carcinoma for which he underwent orthotopic liver transplantation in ***,he developed end-stage renal disease,requiring hemodialysis in *** 2018,the diagnosis of high-risk essential thrombocythemia(ET)(presence of the JAK2(V617F)mutation and advanced age without a history of thrombosis)was made.

关键词： liver diagnosis JAK2

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Performance Back-deduction from a Loading to Flow Coefficient Map:Application to Radial Turbine

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Journal of Thermal Science 2012年第6期21卷 509-517页

作者： xavier CARBONNEAU Nicolas BINDER Université de Toulouse Institut Supérieur de l'Aéronautique et de l'Espace(ISAE)10avenue Edouard Belin BP 54032 31400 ToulouseFrance

Radial turbine stages are often used for applications requiring off-design operation,as turbocharging for *** off-design ability of such stages is commonly analyzed through the traditional turbine map,plotting the reduced mass-flow against the pressure-ratio,for reduced-speed ***,some alternatives are possible,such as the flow-coefficient(Ψ)to loading-coefficient(φ)diagram where the pressure-ratio lines are actually straight lines,very convenient property to perform prediction.A robust method re-creating this map from a predicted Ψ-φ diagram is *** work has shown that this back-deduction quality,without the use of any loss models,depends on the knowledge of an intermediate pressure-ratio.A modelization of this parameter is then *** comparison with both experimental and CFD results is presented,with quite good agreement for mass flow rate and rotational speed,and for the intermediate pressure *** last part of the paper is dedicated to the application of the intermediate pressure-ratio knowledge to the improvement of the deduction of the pressure ratio lines in the Ψ-φ *** this improvement,the back-deduction method of the classical map is structured,applied and evaluated.

关键词：径流式涡轮应用程序流量系数装载系数涡轮机地图返回性能

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WTR:A Reputation Metric for Distributed Hash Tables Based on a Risk and Credibility Factor

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Journal of Computer Science & Technology 2009年第5期24卷 844-854页

作者： xavier Bonnaire Erika Rosas Departamento de Informatica Universidad Tecnica Federico Santa MariaValparaisoChile Laboratoire d'Informatique de Paris 6 Universite Pierre et Marie CurieCNRS UMR 7606 INRIA REGALParisFrance

The growing number of popular peer to peer applications during the last five years has implied for researchers to focus on how to build trust in such very large scale distributed systems. Reputation systems have shown to be a very good solution to build trust in presence of malicious nodes. We propose in this paper a new metric for reputation systems on top of a Distributed Hash Table that uses a notion of risk to make the applications aware of certain behaviours of malicious nodes. We show that our metric is able to significantly reduce the number of malicious transactions, and that it also provides very strong resistance to several traditional attacks of reputations systems. We also show that our solution can easily scale, and can be adapted to various Distributed Hash Tables.

关键词： peer to peer reputation system risk evaluation

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Surgery for metastatic pancreatic neuroendocrine tumors: a narrative review

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Hepatobiliary Surgery and Nutrition 2023年第1期12卷 69-83页

作者： Jelani K.Williams Jason L.Schwarz xavier M.Keutgen Division of General Surgery and Surgical Oncology Department of SurgeryUniversity of Chicago MedicineChicagoILUSA

Background and Objective:Pancreatic neuroendocrine tumors(PanNETs)are derived from the islet cells of the pancreas and have been increasing in *** of these tumors are nonfunctional although some can secrete hormones and lead to hormone-specific clinical *** is the mainstay of treatment for localized tumors,however,surgical resection is controversial in metastatic *** narrative review seeks to summarize the current literature surrounding surgery,specifically in the controversial area of metastatic PanNETs,review current treatment paradigms,and understand the benefits of surgery in this group of ***:Authors searched PubMed using the terms“surgery pancreatic neuroendocrine tumor”,“metastatic neuroendocrine tumor”,and“liver debulking neuroendocrine tumor”from January 1990 to June *** English language publications were *** Content and Findings:There is no consensus among the leading specialty organizations regarding surgery for metastatic *** considering surgery for metastatic PanNETs,tumor grade and morphology,location of the primary tumor,extra-hepatic or extra-abdominal disease,as well as liver tumor burden and metastatic distribution should be *** the liver is the most common site of metastasis and liver failure is the most common cause of death in patients with hepatic metastases,attention is centered here on debulking and other ablative *** transplantation is rarely used for hepatic metastases but could be beneficial in a small subset of *** studies have demonstrated improvement in survival and symptoms after surgery for metastatic disease,but the lack of prospective randomized control trials significantly limits analysis of surgical benefits in patients with metastatic ***:Surgery is the standard of care for localized PanNETs,while it remains controversial in metastatic *** studies have shown a survival and symptomatic be

关键词： Pancreatic neuroendocrine tumors(PanNETs) liver tumor burden hepatic metastasis liver debulking DOTATATE

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Towards electrochemical hydrogen storage in liquid organic hydrogen carriers via proton-coupled electron transfers

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Journal of Energy Chemistry 2022年第10期31卷 292-300,I0007页

作者： Hamid Ghorbani Shiraz Mikhail Vagin Tero-Petri Ruoko Viktor Gueskine Krzysztof Karon Mieczystaw tapkowski Tobias Abrahamsson Thomas Ederth Magnus Berggren xavier Crispin Laboratory of Organic Electronics Department of Science and Technology(ITN)Linkoping UniversitySE-60174 NorrkopingSweden Smart Photonic Materials Facuty of Engineering and Natural SciencesTampere UniversiyPBox 541.Tampere Fl-33101Finland Silesian University of Technology.Faculty of Chemistry Deparment of Physical Chemistry and Technology of PolymersM.Strzody 9.44-100 GliwicePoland dDepartment of Physics Chemistry and Biology(IFM)Linkoping UniversiySE-58183 LinkopingSweden

Green hydrogen is identified as one of the prime clean energy carriers due to its high energy density and a zero emission of CO_(2).A possible solution for the transport of H_(2)in a safe and low-cost way is in the form of liquid organic hydrogen carriers(LOHCs).As an alternative to loading LOHC with H_(2)via a two-step procedure involving preliminary electrolytic production of H_(2)and subsequent chemical hydrogenation of the LOHC,we explore here the possibility of electrochemical hydrogen storage(EHS)via conversion of proton of a proton donor into a hydrogen atom involved in covalent bonds with the LOHC(R)via a protoncoupled electron transfer(PCET)reaction:2nH^(+)+2ne^(-)+Rox■n H_(2)^(0)*** chose 9-fluorenone/fluorenol(Fnone/Fnol)conversion as such a model PCET *** electrochemical activation of Fnone via two sequential electron transfers was monitored with in-situ and operando spectroscopies in absence and in presence of different alcohols as proton donors of different reactivity,which enabled us to both quantify and get the mechanistic insight on *** possibility of hydrogen extraction from the loaded carrier molecule was illustrated by chemical activation.

关键词： Proton-coupled electron transfer Electrochemical hydrogen storage Hydrogen bonding agent Anion-radical Comproportionation

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