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Analysis of alternative parameters of dynamic resistance measurement in high voltage circuit breakers

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High voltage 2019年第3期4卷 197-202页

作者： Herbet Filipe dos Santos Sousa Adriano Costa de Oliveira George victor Rocha Xavier Henrique Nunes de Santana Edson Guedes da Costa tarso vilela ferreira Federal University of Campina Grande Campina GrandeBrazil Federal University of Sergipe AracajuBrazil

Throughout its lifetime,high-voltage circuit breaker(HvCB)contacts suffer from inevitable degradation processes,especially during the formation of electric *** degraded contacts can reduce the current interruption capacity and increase the chances of operational faults,which might lead to considerable financial ***,the use of efficient evaluating techniques is a key factor to achieve systems *** dynamic resistance measurement(DRM)is a technique that can be used to evaluate the degradation level of HvCB'*** stands out from the usual technique,static resistance measurement,by allowing the assessment of both the main contacts and the arcing contacts(ACs).Usually,the mean resistance or the area under the DRM curve is used to estimate the AC ***,DRM is a non-standardised technique and there are no specified parameters to evaluate the real wear ***,an analysis of alternative parameters extractible from the DRM technique is presented in this study,such as amplitude and variance of the DRM *** results attest the possible use of more than one parameter for the continuous evaluation of HvCB ACs,characterising the DRM as a more complete and precise diagnosis tool.

关键词： resistance parameters dynamic

Nanocellulose-based porous materials: Regulation and pathway to commercialization in regenerative medicine

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Bioactive Materials 2023年第11期29卷 151-176页

作者： Filipe v.ferreira Alana G.Souza Rubina Ajdary Lucas P.de Souza Jo˜ao H.Lopes Daniel S.Correa Gilberto Siqueira Hernane S.Barud Derval dos S.Rosa Luiz H.C.Mattoso Orlando J.Rojas Nanotechnology National Laboratory for Agriculture(LNNA) Embrapa Instrumentation-Rua XV de Novembro1452S˜ao CarlosSP13560-979Brazil Center for Engineering Modelingand Applied Social Sciences(CECS)Federal University of ABC(UFABC)Santo Andr´eBrazil Department of Bioproducts and Biosystems School of Chemical EngineeringAalto UniversityP.O.Box 16300AaltoEspooFIN-00076Finland College of Engineering and Physical Sciences Aston Institute of Materials ResearchAston UniversityBirminghamUK Department of Chemistry Division of Fundamental Sciences(IEF)Technological Institute of Aeronautics(ITA)S˜ao Jose dos CamposSPBrazil Laboratory for Cellulose&Wood Materials Empa-Swiss Federal Laboratories for Materials Science and TechnologyÜberlandstrasse 1298600DübendorfSwitzerland Biopolymers and Biomaterials Laboratory(BIOPOLMAT) University of Araraquara(UNIARA)Araraquar114801-340S˜ao PauloBrazil Bioproducts Institute Department of Chemical&Biological EngineeringDepartment of Chemistry andDepartment of Wood ScienceThe University of British Columbi12360 East MallVancouverBCV6T 1Z3Canada

We review the recent progress that have led to the development of porous materials based on cellulose nanostructures found in plants and other resources. In light of the properties that emerge from the chemistry, shape and structural control, we discuss some of the most promising uses of a plant-based material, nanocellulose, in regenerative medicine. Following a brief discussion about the fundamental aspects of self-assembly of nanocellulose precursors, we review the key strategies needed for material synthesis and to adjust the architecture of the materials (using three-dimensional printing, freeze-casted porous materials, and electrospinning) according to their uses in tissue engineering, artificial organs, controlled drug delivery and wound healing systems, among others. For this purpose, we map the structure-property-function relationships of nanocellulose-based porous materials and examine the course of actions that are required to translate innovation from the laboratory to industry. Such efforts require attention to regulatory aspects and market pull. Finally, the key challenges and opportunities in this nascent field are critically reviewed.

关键词： Cellulose nanofibrils Cellulose nanocrystals Regenerative medicine Biomaterial Sustainable materials Green nanomaterials

Enhancing production monitoring: A back allocation methodology to estimate well flow rates and assist well test scheduling

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Petroleum Research 2024年第3期9卷 369-379页

作者： G.S.Chaves v.J.M.ferreira Filho Universidade Federal Do Rio de Janeiro Brazil

Production flow rates are crucial to make operational decisions,monitor,manage,and optimize oil and gas *** rates also have a financial importance to correctly allocate production to fiscal purposes required by regulatory agencies or to allocate production in fields owned by multiple *** its significance,usually only the total field production is measured in real time,which requires an alternative way to estimate wells'*** address these challenges,this work presents a back allocation methodology that leverages real-time instrumentation,simulations,algorithms,and mathe-matical programming modeling to enhance well monitoring and assist in well test *** methodology comprises four modules:simulation,classification,error calculation,and *** modules work together to characterize the flowline,wellbore,and reservoir,verify simulation outputs,minimize errors,and calculate flow rates while honoring the total platform flow *** well status generated through the classification module provides valuable information about the current condition of each well(*** the well is deviating from the latest well test parameters),aiding in decision-making for well testing scheduling and *** effectiveness of the methodology is demonstrated through its application to a representative offshore oil field with 14 producing wells and two years of daily production *** results highlight the robustness of the methodology in properly classifying the wells and obtaining flow rates that honor the total platform flow ***,the methodology supports well test scheduling and provides reliable indicators for well *** uti-lizing real-time data and advanced modeling techniques,this methodology enhances production monitoring and facilitates informed operational decision-making in the oil and gas industry.

关键词： Production estimation Real-time production Production monitoring Back allocation Well test scheduling Flow rate estimation

The use of Artificial Neural Networks to estimate seismic damage and derive vulnerability functions for traditional masonry

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Frontiers of Structural and Civil Engineering 2020年第3期14卷 609-622页

作者： Tiago Miguel ferreira Joao ESTEvAO Rui MAIO Romeu vICENTE ISISE Institute of Science and Innovation for Bio-Sustainability(IB-S)Department of Civil EngineeringUniversity of MinhoGuimaraes 4800-058Portugal Department of Civil Engineering University of AlgarveFaro 8005-139Portugal RISCO Department of Civil EngineeringUniversity of AveiroAveiro 3810-193Portugal

ABSTRACT This paper discusses the adoption of Artificial Intelligence-based techniques to estimate seismic damage,not with the goal of replacing existing approaches,but as a mean to improve the precision of empirical *** such,damage data collected in the aftermath of the 1998 Azores earthquake(Portugal)is used to develop a comparative analysis between damage grades obtained resorting to a classic damage formulation and an innovative approach based on Artificial Neural Networks(ANNs).The analysis is carried out on the basis of a vulnerability index computed with a hybrid seismic vulnerability asssment methodology,which is subsequently used as input to both *** results obtained are then compared with real post-earthquake damage observation and critically discussed taking into account the level of adjustment achieved by each ***,a computer routine that uses the ANN as an approximation function is developed and applied to derive a new vulnerability curve *** general terms,the ANN developed in this study allowed to obtain much better approximations than those achieved with the original vulnerability approach,which has revealed to be quite ***,the proposed vulnerability curve expression was found to provide a more accurate damage prediction than the traditional analytical expressions.

关键词： Artificial Neural Networks seismic vulnerability masonry buildings damage estimation,vulnerability curves

Innate and adaptive immune responses in male and female reproductive tracts in homeostasis and following HIv infection

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Cellular & Molecular Immunology 2014年第5期11卷 410-427页

作者： Philip v Nguyen Jessica K Kafka victor H ferreira Kristy Roth Charu Kaushic McMaster Immunology Research Centre (MIRC) and Michael G.DeGroote Institute ot Intectious Dtseas Research (IIDR) Department of Pathology and Molecular Medicine McMaster University Hamilton Ontario Canada

The male and female reproductive tracts are complex microenvironments that have diverse functional demands. The immune system in the reproductive tract has the demanding task of providing a protective environment for a fetal allograft while simultaneously conferring protection against potential pathogens. As such, it has evolved a unique set of adaptations, primarily under the influence of sex hormones, which make it distinct from other mucosal sites. Here, we discuss the various components of the immune system that are present in both the male and female reproductive tracts, including innate soluble factors and cells and humoral and cell-mediated adaptive immunity under homeostatic conditions. We review the evidence showing unique phenotypic and functional characteristics of immune cells and responses in the male and female reproductive tracts that exhibit compartmentalization from systemic immunity and discuss how these features are influenced by sex hormones. We also examine the interactions among the reproductive tract, sex hormones and immune responses following HIv-1 infection. An improved understanding of the unique characteristics of the male and female reproductive tracts will provide insights into improving clinical treatments of the immunological causes of infertility and the design of prophylactic interventions for the prevention of sexually transmitted infections.

关键词： female reproductive tract genital immunity HIv-1 male reproductive tract mucosal immune responses sexhormones sexually transmitted infections

Thermodynamic analysis, synthesis, characterization, and evaluation of 1-ethyl-3-methylimidazolium chloride: Study of its effect on pretreated rice husk

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Chinese Journal of Chemical Engineering 2023年第8期60卷 143-154页

作者： Eileen Katherine Coronado-Aldana Cindy Lizeth ferreira-Salazar Nubia Yineth Piñeros-Castro Rubén vázquez-Medina Felipe A.Perdomo Universidad de BogotáJorge Tadeo Lozano Facultad de Ciencias Naturales e IngenieríaCra.422-61CundinamarcaBogotáColombia Instituto Politecnico Nacional CICATA QueretaroCerro Blanco 141Colinas del Cimatario76090 QueretaroMexico School of Engineering University of EdinburghEdinburgh EH93FBUnited Kingdom

This work is focused on the determination of the optimal reaction conditions to synthesize the ionic liquid 1-ethyl-3-methylimidazolium chloride([EMIM][Cl]) and assess its suitability for the pretreatment of rice husk. The modified UNIFAC(UNIversal quasi-chemical Functional-group Activity Coefficients)approach for ionic liquids is used to develop a thermodynamic model that describes the reactive system methylimidazole(MIM), chloroethane(C_(2)H_(5)Cl) and [EMIM][Cl]. The model allows to study the phase equilibria coexistence(vapor–liquid equilibria and solid–liquid equilibria) and yields the theoretically optimal conditions to synthesize the ionic liquid. The model predictions are validated with the available experimental and reported data. By implementing the developed model, a simple way to synthesize ionic liquid [EMIM][Cl] was found allowing to study its influence on the structure and morphology of pretreated rice husk. The lignocellulosic materials involved in this study are characterized by their composition, enzymatic digestibility, scanning electron microscopy, and crystallinity. Compared to untreated material, [EMIM][Cl]-pretreated rice husk produces cellulose that can be efficiently enzymatic hydrolyzed with high sugar yields. This work offers a suitable methodology to include the synthesis and thermodynamics of the solvent media within the design of low-cost ionic liquids for lignocellulosic biomass pretreatment.

关键词： Ionic liquids Fluid-phase equilibria Thermodynamics Waste treatment UNIFAC approach

A Chopper Negative-R Delta-Sigma ADC for Audio MEMS Sensors

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Computer Modeling in Engineering & Sciences 2022年第2期130卷 607-631页

作者： Jamel Nebhen Pietro M.ferreira College of Computer Engineering and Sciences Prince Sattam bin Abdulaziz UniversityAlkharj11942Saudi Arabia Universit´e Paris-Saclay Centrale SupelecCNRSLaboratory de G´enie Electrique et Electronique de ParisGif-sur-Yvette91192France Sorbonne Universite CNRSLab.de Genie Electrique et Electronique de ParisParis75252France

This paper presents a proposed low-noise and high-sensitivity Internet of Thing(IoT)system based on an M&NEMS *** IoT device consists of an M&NEMS resistive accelerometer associated with an electronic readout circuit,which is a silicon nanowire and a Continuous-Time(CT)△∑*** first integrator of the△∑ADC is based on a positive feedback DC-gain enhancement two-stage amplifier due to its high linearity and low-noise *** mitigate both the offset and 1/f noise,a suggested delay-time chopper negative-R stabilization technique is applied around the first integrator.A 65-nm CMOS process implements the CT△∑*** supply voltage of the CMOS circuit is 1.2-v while 0.96-mW is the power consumption and 0.1-mm^(2) is the silicon *** M&NEMS microphone and△∑ADC complete circuit are fabricated and *** a working frequency bandwidth of 20-kHz,the measurement results of the proposed IoT system reach a signal to noise ratio(SNR)of ***,it has a measured dynamic range(DR)of 108-dB and a measured signal to noise and distortion ratio(SNDR)of 101.3-dB.

关键词： M&NEMS sensor △∑ ADC chopper negative-R IoT 1/f noise SNR

Phase separation and coarsening of NiAl(β′)intermetallic in quench-aged Fe-Ni-Al alloys

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Journal of Iron and Steel Research International 2020年第11期27卷 1331-1338页

作者： C.ferreira-Palma J.A.Rosas-Barrios v.M.Lopez-Hirata D.I.Rivas-Lopez H.J.Dorantes-Rosales Faculty of Chemical Sciences Universidad VeracruzanaVeracruz 94294Mexico ESIQIE Instituto Politecnico Nacional.UPALMMexico City 07738Mexico

The coarsening behavior of four quench-aged Fe-Ni-AI alloys with different Ni and Al con tents is *** alloys were solubilized at 1100℃for 24 h,water-quenched and aged at 850℃for periods ranging from 1 to 100 h to promote phase separation and *** two alloys with the highest combined Ni and Al contents(>35 at.%)showed signs of spinodal decomposition,while the alloys with lower Ni and Al contents followed a classical nucleation *** Ni and Al contents promoted an increase in NiAl(β′)phase fraction in concordance with phase equilibrium *** alloy with the highest[3'fraction presented a completely interconnected *** coarsening ofβ′particles in the other three alloys followed the predictions of the Lifshitz-Slyozov-Wagner(LSW)*** general trend was an increase in the coarsening kinetics with higher Ni and Al *** highest hardness was found in the alloys with higher fraction albeit these compositions are less resistant to coarsening and have been reported to present a low room-temperature ductility.

关键词： Precipitation Spinodal decomposition Coarsening Aging Fe-Ni-Al alloy

超声波与人工智能在现场绝缘诊断中的应用(英文)

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高电压技术 2012年第8期38卷 1842-1847页

作者： ferreira T v Germano A D Silva K M Costa E G Department of Electrical Engineering Federal University of Campina GrandeCampina Grande Institute for High voltage Technology and Power Transmission Technische Universitt München Department of Electrical Engineering University of Brasília

This work studies the feasibility of implementing a system for diagnosis of electrical insulation in the field based on ultrasonic noise and artificial neural *** system,proved functional under laboratory conditions,extracts spectral information from the ultrasonic noise emitted by the corona discharges in electric equipments,and correlates it with previously defined degrees of *** achieve this classification,artificial neural networks are *** results show the viability of the method in the site;nevertheless they also show that its reliability is proportional to the size and diversity of the available database.

关键词：局部放电射频信号放电量高电压技术