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High Voltage 2021年第1期6卷 82-94页

作者： johnatan m.rodríguez‐serna Ricardo Albarracín‐Sánchez Department of Electrical and Electronic Engineering Automatic Controland Applied PhysicsSchool of Industrial Design and Engineering(ETSIDI)Universidad Politécnica de Madrid(UPM)MadridSpain Department of Electrical Engineering Universidad de AntioquiaMedellínColombia

Electrical trees are defects originated and driven by partial discharges(PD)activity and this is the reason why their modelling and simulation are fundamental for the ageing mechanisms comprehension and diagnosis analyses of insulation systems compound by solid *** study presents a brief review of the different models implemented to simulate PD in electrical trees inside solid *** addition,an improved deterministic model as well as a stochastic model are presented,which allow predicting adequately the PD pulses distribution,in magnitudes and phase,for non‐conducting electrical trees of different shape and *** case studies were simulated and their results exhibit good agreement when compared with measurements presented in the *** is concluded that the main parameters that state the PD behaviour in trees are the inception and extinction voltage mag-nitudes,including their probability distributions,and the tree *** models can be used for prognosis analysis based on on‐line measurements.

关键词： solid conducting electrical

Finite-element-analysis models for numerical simulation of partial discharges in spherical cavities within solid dielectrics:a review and a novel method

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High Voltage 2020年第5期5卷 556-568页

作者： johnatan m.rodríguez-serna Ricardo Albarracín-Sánchez Abdullahi A.mas'ud Department of Electrical and Electronic Engineering Automatic Controland Applied PhysicsSchool of Industrial Design and Engineering(ETSIDI)Universidad Politécnica de Madrid(UPM)Ronda de Valencia 328012MadridSpain 2Department of Electrical EngineeringUniversidad de AntioquiaCalle 67 No.53-108MedellínColombia 3Department of Electrical and Electronic Engineering TechnologyJubail Industrial College31961JubailSaudi Arabia

During the last two decades,partial discharges(PDs)modelling methods have been used as a complement of insulation diagnosis systems of electrical ***-element-analysis models for simulating PDs in cavities within solid dielectric materials are reviewed and a novel model is presented,which combines the main advantages of electrostatic and electric current *** theoretical background is presented and some limitations and restrictions are discussed.A case of study was implemented for three different ageing conditions and simulation results exhibit good agreement with reported values by other authors in the *** analysis of variations of PD behaviour with ageing as a function of temperature and pressure is briefly *** is concluded that more research is needed to include physical and chemical interactions on the void surface and that the cavity surface conductivity plays a fundamental role in the PD simulations at advanced ageing conditions.

关键词： element analysis solid

OTB-morph:One-time Biometrics via morphing

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machine Intelligence Research 2023年第6期20卷 855-871页

作者： mahdi Ghafourian Julian Fierrez Ruben Vera-rodriguez Aythami morales Ignacio serna Biometrics and Data Pattern Analytics Laboratory(BiDA Lab) Universidad Autonoma de MadridMadrid28049Spain

Cancelable biometrics are a group of techniques to transform the input biometric to an irreversible feature intentionally using a transformation function and usually a key in order to provide security and privacy in biometric recognition *** transformation is repeatable enabling subsequent biometric *** paper introduces a new idea to be exploited as a transformation function for cancelable biometrics aimed at protecting templates against iterative optimization *** proposed scheme is based on time-varying keys(random biometrics in our case)and morphing *** experimental implementation of the proposed scheme is given for face *** results confirm that the proposed approach is able to withstand leakage attacks while improving the recognition performance.

关键词： Biometrics face recognition template protection morphing security

Extremal Coalitions for Influence Games Through Swarm Intelligence-Based methods

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Computers, materials & Continua 2022年第3期70卷 6305-6321页

作者： Fabián Riquelme rodrigo Olivares Francisco munoz Xavier molinero maria serna Escuela de Ingeniería Informática Universidad de ValparaísoValparaísoChile Computer Science Department Universitat Politècnica de CatalunyaBarcelonaSpain mathematics Department Universitat Politècnica de CatalunyaTerrassaSpain

An influence game is a simple game represented over an influence graph(i.e.,a labeled,weighted graph)on which the influence spread phenomenon is *** games allow applying different properties and parameters coming from cooperative game theory to the contexts of social network analysis,decision-systems,voting systems,and collective *** exact calculation of several of these properties and parameters is computationally hard,even for a small number of *** examples of these parameters are the length and the width of a *** length of a game is the size of its smaller winning coalition,while the width of a game is the size of its larger losing *** parameters are relevant to know the levels of difficulty in reaching agreements in collective decision-making *** the above,new bio-inspired metaheuristic algorithms have recently been developed to solve the NP-hard influence maximization problem in an efficient and approximate way,being able to find small winning coalitions that maximize the influence spread within an influence *** this article,we apply some variations of this solution to find extreme winning and losing coalitions,and thus efficient approximate solutions for the length and the width of influence *** a case study,we consider two real social networks,one formed by the 58 members of the European Union Council under nice voting rules,and the other formed by the 705 members of the European Parliament,connected by political *** are promising and show that it is feasible to generate approximate solutions for the length and width parameters of influence games,in reduced solving time.

关键词： Influence game influence spread collective behavior swarm intelligence bio-inspired computing

Electrochemical Corrosion Study in H₂SO₄ of NiAl with Cu Additions, microstructure and micro-Hardness at Room Temperature

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Journal of minerals and materials Characterization and Engineering 2022年第3期10卷 225-241页

作者： Jesús m. Colín de la Cruz Sergio A. serna Barquera Alvaro Torres-Islas Arturo molina-Ocampo Edgar Valenzuela José G. González rodríguez Universidad Autónoma del Estado de morelos Facultad de Ciencias Químicas e Ingeniería UAEM-FCQeI. Av. Universidad 1001Colonia Chamilpa Cuernavaca Morelos México Universidad Autónoma del Estado de morelos Centro de Investigación en Ingeniería y Ciencias Aplicadas UAEM-CIICAp Cuernavaca Morelos México UABC Baja California Sur México

For many years, intermetallic materials promise applications in a wide variety of technology areas. NiAl intermetallic compound is material that exhibits important characteristics such as high corrosion resistance and low density besides its ability to retain strength and stiffness at elevated temperatures. However NiAl intermetallic is too hard, brittle and exhibits very low ductility at room temperature being the reason because this material is not yet available for structural applications. In order to increase the ductility of the NiAl intermetallic compound, the addition of a third alloying element has been proved, nevertheless it is important to determine if such additions decrease or increase the hardness and the corrosion resistance of the alloy. So, the present investigation reports the corrosion performance of the NiAl intermetallic compound modified with Cu, emphasizing the EIS analysis and the relation between physical parameters and the modelling equations used in the Equivalent Electric Circuit. It was found that the addition of Cu promotes the formation of the γ’-Ni3Al phase in Cu contents greater than 15 at. %, in addition to a decrease in micro hardness and an increment in the Icorr values. In this way, the electrochemical characterization evidenced a high corrosion resistance of these intermetallic alloys.

关键词： NiAl-Cu Corrosion Behavior Electrochemical Impedance Spectrum Vickers micro Hardness microstructure

Rheumatoid Factor and Anti Citrulinated Peptide. Relation with Remission and Progression in Rheumatoid Arthritis with Biologic Agent Therapy, during a One-Year Follow-Up

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Open Journal of Rheumatology and Autoimmune Diseases 2014年第1期4卷 34-38页

作者： Asunción Acosta Pereira Berta magallares López Esther moga Naranjo Arturo rodríguez de la serna Division of Rheumatology Department of Internal Medicine Hospital Sant Pau Barcelona Spain.

The aim of this study is to assess the variations of the RF and ACCP in RA patients treated with biologics in actual clinical practice (real) conditions for a one-year follow-up from the first biologic medication. The evaluated patients with a diagnosis of RA, according to the American College of Rheumatology (ACR) 1987 were selected from the outpatient consult of Rheumatology of the “Hospital de Sant Pau” during one month (November 2012). We collected and analyzed data from 41 patients with RA and positivity for RF and/or ACCP. Of the 41 patients had given FR and ACCP at 3, 6 and 12 months respectively in 18 and 10 patients. In 22 patients had given DAS 28 at 3, 6 and 12 months respectively. The mean age of the sample is 55 years (range 29-79), with a mean disease progression 9 years (4 months to 32 years). 70% are women. 33 patients (80.5%) initiated treatment with anti-TNF and 8 (19.5%) with other no anti-TNF mechanism of action. There was a statistically significant (p = 0.001, ANOVA) decrease in DAS 28 (average decrease of 1.6 points) at 3 months is maintained at 6 and 12 m and no significant differences in their evolution by separating anti-TNF drugs vs. other biological agents (different mechanisms of action (p = 0.285). So we have not detected a correlation between DAS 28 and FR or ACCP along the first 12 months of biological treatment. In our experience we did not find a correlation between DAS 28 and RF or ACCP, thus RF and ACCP do not appear to predict the response to treatment.

关键词： Rheumatoid Arthritis Rheumatoid Factor Anticitrulin Antibodies

Nonlinear optical properties of integrated GeSbS chalcogenide waveguides

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Photonics Research 2018年第5期6卷 I0062-I0067页

作者： SAmUEL serna HONGTAO LIN CARLOS ALONSO-RAmOS ANUPAmA YADAV XAVIER LE ROUX KATHLEEN RICHARDSON ERIC CASSAN NICOLAS DUBREUIL JUEJUN HU LAURENT VIVIEN Centre de Nanosciences et de Nanotechnologies (C2N) CNRS Univ.Paris-Sud Université Paris SaclayC2N Orsay Laboratoire Charles Fabry Institut d'Optique Graduate SchoolCNRS Université Paris Saclay Department of materials Science and Engineering Massachusetts Institute of Technology-MIT College of Optics and Photonics-CREOL University of Central Florida

In this paper, we report the experimental characterization of highly nonlinear Ge Sb S chalcogenide glass *** used a single-beam characterization protocol that accounts for the magnitude and sign of the real and imaginary parts of the third-order nonlinear susceptibility of integrated Ge23 Sb7 S70(GeSbS) chalcogenide glass waveguides in the near-infrared wavelength range at λ =1580 nm. We measured a waveguide nonlinear parameter of 7.0±0.7 W^(-1)· m(-1), which corresponds to a nonlinear refractive index of n_2=0.93±0.08 × 10^(-18) m^2∕W,comparable to that of silicon, but with an 80 times lower two-photon absorption coefficient βTPA=0.010± 0.003 cm∕GW, accompanied with linear propagation losses as low as 0.5 dB/cm. The outstanding linear and nonlinear properties of Ge Sb S, with a measured nonlinear figure of merit FOmTPA=6.0 ±1.4 at λ =1580 nm, ultimately make it one of the most promising integrated platforms for the realization of nonlinear functionalities.

关键词： Sb Nonlinear optical properties of integrated GeSbS chalcogenide waveguides

Effects of dielectric stoichiometry on the photoluminescence properties of encapsulated WSe2 monolayers

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Nano Research 2018年第3期11卷 1399-1414页

作者： Javier martfn-Sanchez Antonio mariscal marta De Luca Aitana Tarazaga martin-Luengo Georg Gramse Alma Halilovic Rosalia serna Alberta Bonanni Ilaria Zardo Rinaldo Trotta Armando Rastelli Institute of Semiconductor and Solid State Physics Johannes Kepler University Linz Altenbergerstrasse 69 A-4040 Linz Austria Laser Processing Group Instituto de Optica CSIC C/Serrano 121 28006 Madrid Spain Department of Physics University of Basel Klingelbergstrasse 82 4056 Basel Switzerland Institute for Biophysics Johannes Kepler University Linz Gruberstrasse 40 A-4020 Linz Austria

Two-dimensional transition metal dichalcogenide semiconductors have emerged as promising candidates for optoelectronic devices with unprecedented properties and ultra-compact footprints. However, the high sensitivity of atomically thin materials to the surrounding dielectric media imposes severe limitations on their practical applicability. Hence, to enable the effective integration of these materials in devices, the development of reliable encapsulation procedures that preserve their physical properties is required. Here, the excitonic photoluminescence （at room temperature and 10 K） is assessed on mechanically exfoliated WSe2 monolayer flakes encapsulated with SiOx and AlxOy layers by means of chemical and physical deposition techniques. Conformal coating on untreated and non- functionalized flakes is successfully achieved by all the techniques examined, with the exception of atomic layer deposition, for which a cluster-like oxide coating is formed. No significant compositional or strain state changes in the flakes are detected upon encapsulation, independently of the technique adopted. Remarkably, our results show that the optical emission of the flakes is strongly influenced by the stoichiometry quality of the encapsulating oxide. When the encapsulation is carried out with slightly sub-stoichiometric oxides, two remarkable phenomena are observed. First, dominant trion （charged exciton） photoluminescence is detected at room temperature, revealing a clear electrical doping of the monolayers. Second, a strong decrease in the optical emission of the monolayers is observed, and attributed to non-radiative recombination processes and/or carrier transfer from the flake to the oxide. Power- and temperature-dependent photoluminescence measurements further confirm that stoichiometric oxides obtained by physical deposition lead to a successful encapsulation, opening a promising route for the development of integrated two-dimensional devices.

关键词： two dimensional (2D)materials dielectric encapsulation transition metaldichalcogenides semiconductors photoluminescence WSe2

Where Are the Bromeliads? A Study on Different Trails in the Ecological Reserve of Guapiaçu, RJ

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Agricultural Sciences 2023年第2期14卷 196-201页

作者： johnatan Jair de Paula marchiori Vinicius de Souza Oliveira Gilcéa Teixeira Fontana Boone Luan Luciano dos Santos Pereira Natália Cristina Barbosa moura Ana Beatriz mamedes Piffer Anderson mathias Holtz Lusiane de Sousa Ferreira Raquel Cetto Sampaio Federal Rural University of Rio de Janeiro Seropédica Brazil Center for Agricultural Sciences and Engineering Federal University of Espírito Santo Alegre Brazil Campus Itapina Federal Institute of Espírito Santo Colatina Brazil State University Paulista “Júlio de mesquita Filho” Botucatu Brazil

Bromeliaceae are important in ecological restoration, showing easy adaptation to different environments, and constantly interacting with each other through ecological relationships, whose effects may or may not benefit the species involved. The hypothesis tested whether the population density of Hohenbergia augusta is higher in areas at a more advanced successional stage (brown trail), since the species is typical of more structured forest environments, occurring especially in the lower strata of the forest. Six plots of 10 meters (6 × 10 m) were installed, parallel to the brown and yellow trails, and with a distance of 5 m from the edge. Plots were allocated alternately between the two sides of the trail, 10 meters apart from each other when on the same side. In each plot, all H. augusta (Vell.) E. morren bromeliads were sampled, without a minimum inclusion criterion, provided they were epiphytic phorophytes. The logarithm of the value was used for data normalization and later, the data were tested in a student’s t-test. The study pointed out that the highest population density of H. augusta occurred in the brown trail because the area is in a more advanced successional stage.

关键词： Bromeliads Atlantic Forest Ecological Restoration

Development and internal validation of the Comprehensive ALPPS Preoperative Risk Assessment(CAPRA)score:is the patient suitable for Associating Liver Partition and Portal vein ligation for Staged hepatectomy(ALPPS)?

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Hepatobiliary Surgery and Nutrition 2022年第1期11卷 52-66,I0007,I0008页

作者： Ivan Capobianco Karl J.Oldhafer mohammed-Hossein Fard-Aghaie Ricardo Robles-Campos Roberto Brusadin Henrik Petrowsky michael Linecker Arianeb mehrabi Katrin Hoffmann Jun Li Asmus Heumann Roberto Hernandez-Alejandro mauro Enrique Tun-Abraham Elio Jovine matteo Serenari Bergthor Bjornsson Per Sandström Ruslan Alikhanov mikhail Efanov Paolo muiesan Andrea Schlegel Thomas m.van Gulik Pim B.Olthof Gregor Alexander Stavrou Lina maria serna-Higuita Alfred Königsrainer Silvio Nadalin Department of General Visceral and Transplant SurgeryUniversity Hospital TübingenTübingenGermany Department of General and Abdominal Surgery Asklepios Hospital BarmbekHamburgGermany Department of Surgery Virgen de la Arrixaca Clinic and University HospitalMurciaSpain Swiss HPB and Transplantation Center Department of SurgeryZurich University HospitalZurichSwitzerland Department of General Visceraland Transplantation SurgeryUniversity of HeidelbergHeidelbergGermany General Visceral and Thoracic Surgery Department and ClinicHamburg-Eppendorf University Medical CenterHamburgGermany Division of Transplantation and Hepatobiliary Surgery University of RochesterRochesterNYUSA Division of HPB Surgery and Liver Transplantation Department of SurgeryLondon Health Sciences CentreLondonCanada General and Emergency Surgery Unit Azienda Ospedaliero-Universitaria di BolognaMaggiore HospitalBolognaItaly General Surgery and Transplantation Unit Azienda Ospedaliero-Universitaria di BolognaSant’Orsola-Malpighi HospitalBolognaItaly Department of Surgery in Linköping and Department of Biomedical and Clinical SciencesLinköping UniversityLinköpingSweden Department of Hepatopancreatobiliary Surgery Moscow Clinical Scientific CenterMoscowRussia Liver Unit Queen Elizabeth Hospital BirminghamUniversity Hospitals Birmingham NHS Foundation TrustBirminghamUK Department of Surgery Amsterdam UMC(Location AMC)University of AmsterdamAmsterdamThe Netherlands Department of General Abdominal and Thoracic SurgerySurgical OncologySaarbruecken General HospitalSaarbrueckenGermany Department of Clinical Epidemiology and Applied Biometry University of TübingenTübingenGermany

Background:Preoperative patient selection in Associating Liver Partition and Portal vein ligation for Staged hepatectomy(ALPPS)is not always reliable with currently available scores,particularly in patients with primary liver *** study aims to(I)to determine whether comorbidities and patients characteristics are a risk factor in ALPPS and(II)to create a score predicting 90-day mortality ***:Thirteen high-volume centers participated in this retrospective multicentric study.A risk analysis based on patient characteristics,underlying disease and procedure type was performed to identify risk factors and model the Comprehensive ALPPS Preoperative Risk Assessment(CAPRA)score.A nonparametric receiver operating characteristic analysis was performed to estimate the predictive ability of our score against the Charlson Comorbidity Index(CCI),the age-adjusted CCI(aCCI),the ALPPS risk score before Stage 1(ALPPS-RS1)and Stage 2(ALPPS-RS2).The model was internally validated applying ***:A total of 451 patients were *** was 14.4%.The CAPRA score is calculated based on the following formula:(0.1×age)−(2×BSA)+1(in the presence of primary liver tumor)+1(in the presence of severe cardiovascular disease)+2(in the presence of moderate or severe diabetes)+2(in the presence of renal disease)+2(if classic ALPPS is planned).The predictive ability was 0.837 for the CAPRA score,0.443 for CCI,0.519 for aCCI,0.693 for ALPPS-RS1 and 0.807 for *** 1,000 cycles of bootstrapping the C statistic was *** accuracy plot revealed a cut-off for optimal prediction of postoperative mortality of ***:Comorbidities play an important role in ALPPS and should be carefully considered when planning the *** assessing the patient’s preoperative condition in relation to ALPPS,the CAPRA score has a very good ability to predict postoperative mortality.

关键词： Associating Liver Partition and Portal vein ligation for Staged hepatectomy(ALPPS) comorbidity mortality prediction model patient selection