检索结果-南通市图书馆

Laser texturing of piston ring for tribological performance improvement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2023年第10期11卷 1895-1905页

作者： Rita FERREIRA Óscar carvalho Luís sOBRAL sandra carvalho Filipe sILVA CMEMs-UMinho University of MinhoGuimarães 4800058Portugal LABBELs-Associate Laboratory Guimarães 4800058Portugal CEMMPRE-Center for Mechanical Engineering Materials and ProcessesUniversity of CoimbraRua Luís Reis SantosCoimbra 3030-788Portugal MAHLE Componentes de MotoresS.A.Núcleo Industrial de MurtedeCantanhede 3060-372Portugal

The radial surface coating layer of compression piston rings is used to improve their wear resistance during the internal combustion engine ***,at top dead centers,the friction coefficient of the piston ring–cylinder liner pair is detrimental to the engine’s tribological *** this work,dimples with different texture dimensions and densities were tested in a home-developed *** friction coefficient was measured for all samples,and for those with the best results,their wear resistance was *** texture with an aspect ratio of 0.25 and a density area of 15%reported the best tribological results.

关键词： piston ring surface texture friction wear

Investigating the physics of disruptions with real-time tomography at JET

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma science and Technology 2022年第3期24卷 80-88页

作者： Diogo R FERREIRA Pedro J carvalho Ivo s carvalho Chris I sTUART Peter J LOMAs JET Contributors 无 Instituto de Plasmas e Fusão Nuclear(IPFN) Instituto Superior Técnico(IST)Universidade de LisboaAv.Rovisco Pais 11049-001 LisboaPortugal Culham Centre for Fusion Energy(CCFE) UK Atomic Energy Authority(UKAEA)Culham Science CentreAbingdonOX143DB OxfordshireUnited Kingdom see the author list of E.Joffrin et al 2019 Nucl Fusion 59112021 EUROfusion Consortium JETCulham Science CentreAbingdonOX143DBUK

As JET is developing and testing operational scenarios for higher fusion performance,an increase in pulse disruptivity is being *** a deeper analysis,we find that several radiative phenomena play an active role in determining the outcome of the *** analysis is enabled by the use of real-time tomography based on the bolometer *** though plasma tomography is an inverse problem,we use machine learning to train a forward model that provides the radiation profile directly,based on a single matrix multiplication *** model is used to investigate radiative phenomena including sawtooth crashes,ELMs and MARFE,and their relationship to the radiated power in different regions of *** particular,we use realtime tomography to monitor the core region,and to throw an alarm whenever core radiation exceeds a certain *** results suggest that this measure alone can anticipate a significant fraction of disruptions in the JET baseline scenario.

关键词： plasma tomography machine learning plasma disruptions

Quo vadis? Bioengineered polysaccharide-based hydrogel scaffolds for damaged central nervous system recovery and regeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第7期17卷 1478-1480页

作者： Isadora C.carvalho Herman s.Mansur Center of Nanoscience Nanotechnology and Innovation-CeNano2IDepartment of Metallurgical and Materials EngineeringFederal University of Minas GeraisBelo HorizonteMGBrazil

Impairments in the central nervous system(CNs)are a prevalent cause of life-long disabilities worldwide,representing serious health,social,and economic concerns(Doblado et al.,2021).During the last decades,with the population eldering and the increase in the life span,we have experienced an increase in CNs-related disorders,like stroke and neurodegenerative diseases(Jarrin et al.,2021).

关键词： al. diseases system

Optical clearing mechanisms characterization in muscle

在线全文

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health sciences 2016年第5期9卷 82-100页

作者： Luís Oliveira M.Inês carvalho Elisabete Nogueira Valery V.Tuchin Physics Department–Polytechnic Institute of Porto school of Engineering Rua Dr.Antonio Bernardino de Almeida 4314200-072 PortoPortugal FEUP–University of Porto Rua Dr.Roberto Frias 4200-465 PortoPortugal CIETI–Centre of Innovation in Engineering and Industrial Technology ISEP Rua Dr.Antonio Bernardino de Almeida4314200-072 PortoPortugal DEEC/FEUP and INEsC TEC University of Porto Rua Dr.Roberto Frias 4200-465 PortoPortugal Research-Education Institute of Optics and Biophotonics saratov National Research state University 83 Astrakhanskaya street Saratov 410012Russia Laboratory of Laser Diagnostics of Technical and Living systems Institute of Precision Mechanics and Control RAs 24 Rabochaya street Saratov 410028Russia Interdisciplinary Laboratory of Biophotonics Tomsk National Research state University 36 Lenin's avenue Tomsk 634050Russia

Optical immersion clearing is a technique that has been widely studied for more than two decades and that is used to originate a temporary transparency effect in biological *** applied in cooperation with clinical methods it provides optimization of diagnosis and treatment *** technique turns biological tissues more transparent through two main mechanisms-tissue dehydration and refractive index(RI)matching between tissue *** matching is obtained by partial replacement of interstit ial water by a biocompat ible agent that presents higher RI and it can be completely rever sible by natural rehydration in vrivo or by assisted rehydration in ex vivo *** data to characterize and discriminate between the two mechanisms and to find new ones are *** a simple method,based on collimated transmittance and thickness measurements made from muscle samples under treatment,we have estimated the diffusion properties of glucose,ethylene glycol(EG)and water that were used to perform such char acterization and *** these properties with data from literature that characterize their diffusion in water we have observed that musde cell membrane permeability limits agent and water diffusion in the *** same experi-mental data has allowed to calculate the optical dearing(OC)eficiency and make an inter-pretation of the internal changes that occurred in muscle during the *** same methodology can now be used to perform similar studies with other agents and in other tissues in order to solve engineering problems at design of inexpensive and robust technologies for a *** improvement of optical tomogr aphic techmiques with better contrast and in depth imaging.

关键词： Collimated transmittance agent diffusivity tissue dehydration thickness variation refractive index matching glucose ethylene glycol

Hydro-wind Optimal Operation for Joint Bidding in Day-ahead Market: storage Efficiency and Impact of Wind Forecasting Uncertainty

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power systems and Clean Energy 2020年第1期8卷 142-149页

作者： António Cerejo sílvio J.P.s.Mariano Pedro M.s.carvalho Maria R.A.Calado Technical-scientific Unity of Electrical and Industrial Engineering Polytechnic Institute of Castelo BrancoAvenida do Empresário6000-767 Castelo BrancoPortugal Department of Electromechanical Engineering University of Beira Interior and Instituto de TelecomunicacoesCalcada Fonte do Lameiro6201-001 CovilhaPortugal Department of Electrical and Computer Engineering Instituto Superior Técnicoand INESC-IDUniversity of LisbonAv.Rovisco Pais1049-001 LisbonPortuga

Wind power production is *** imbalance between committed and delivered energy in pool markets leads to the increase of system costs,which must be incurred by defaulting producers,thereby decreasing their *** avoid this situation,wind producers can submit their bids together with hydro *** the mismatches between the predicted and supplied wind power can be used by hydro producers,turbining or pumping such differences when *** study formulates the problem of hydro-wind production optimization in operation contexts of pool *** problem is solved for a simple three-reservoir cascade case to discuss optimization *** results show a depreciation in optimal revenues from hydro power when wind forecasting is *** depreciation is caused by an asymmetry in optimal revenues from positive and negative wind power *** problem of neutralizing the effect of forecasting uncertainty is subsequently formulated and solved for the three-reservoir *** results are discussed to conclude the impacts of uncertainty on joint bidding in pool market contexts.

关键词： Optimization hydro power wind power uncertainty joint bidding pool market

Artificial intelligence application in diagnostic gastrointestinal endoscopy-Deus ex machina?

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2021年第32期27卷 5351-5361页

作者： Fábio Pereira Correia Luís carvalho Lourenço Department of Gastroenterology Hospital Prof.Dr Fernando FonsecaLisbon 2720-276Portugal

The close relationship of medicine with technology and the particular interest in this symbiosis in recent years has led to the development of several computed artificial intelligence(AI)systems aimed at various areas of medicine.A number of studies have demonstrated that those systems allow accurate diagnoses with histological precision,thus facilitating decision-making by clinicians in real *** the field of gastroenterology,AI has been applied in the diagnosis of pathologies of the entire digestive tract and their attached glands,and are increasingly accepted for the detection of colorectal polyps and confirming their histological *** have shown high accuracy,sensitivity,and specificity in relation to expert endoscopists,and mainly in relation to those with less *** applications that are increasingly studied and with very promising results are the investigation of dysplasia in patients with Barrett's esophagus and the endoscopic and histological assessment of colon inflammation in patients with ulcerative *** some cases AI is thus better than or at least equal to human ***,additional studies are needed to reinforce the existing data,and mainly to determine the applicability of this technology in other *** review summarizes the state of the art of AI in gastroenterological pathology.

关键词： Artificial intelligence Computer-aided diagnosis Deep learning gastrointestinal endoscopy Colorectal polyps Dysplasia

Addressing inclusion,innovation,and sustainability challenges through the lens of economic geography:Introducing the hierarchical regional innovation system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geography and sustainability 2024年第1期5卷 1-12页

作者： Iván Tartaruga Fernanda sperotto Luís carvalho Centre of studies in Geography and spatial Planning(CEGOT) Faculty of Arts and HumanitiesUniversity of PortoPorto 4150-564Portugal school of Economics and Management University of PortoPortoPortugal

The world is facing dramatic challenges related to environmental sustainability at an accelerating *** this context,the field of economic geography(EG)has been playing an important role in understanding both the socioeconomic and technological dimensions of these challenges,as it deals with a variety of complementary notions and *** from this lens,our aim is to explore a conceptual framework that can help us to understand environmental changes relating to multi-dimensional territorial development,notably in eco-nomic contexts where inequality is high,and stratification based on hierarchies regulate social and economic *** on the territory concept,we propose the original notion of a hierarchical regional innovation system(HRIs)that emphasises the pervasive role of hierarchies(powers)in regional innovation systems and illustrate its value with evidence and case studies from extant literature on sustainability *** HRIs can help us understand and promote development paths considering the contribution of inclusive eco-innovations(another original conceptual amalgam).Through some empirical cases from other studies in low-carbon transitions,we show the application of the HRIs(and inclusive eco-innovation)*** conclusion,we provide incen-tives to explore new regional innovation systems,alongside the HRIs,adapted to different regions worldwide and centred on the inclusiveness of people and places.

关键词： Inclusive eco-innovation Inclusive innovation Hierarchical regional innovation system(HRIs) Territorial development sustainable development sustainability transitions

The Gender Patenting Gap: A study on the Iberoamerican Countries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Data and Information science 2020年第3期5卷 116-128页

作者： Danilo s.carvalho Lydia Bares Kelyane silva Center for Technological Development in Health(CDTs) Oswaldo Cruz FoundationRio de JaneiroBrazil Department of General Economics University of Cadiz Av.Enrique Villegas Velez211002CadizSpain Intellectual Property Academy Brazilian National Institute of Industrial PropertyRio de JaneiroBrazil

Purpose: This work presents a study on the female involvement in patent applications in all 23 Ibero-American countries that are WIPO members, in order to measure gender inequalities in institutional collaborations and technological fields, across ***/methodology/approach: The data used in this paper come from EPO Worldwide Patent statistical Database(PATsTAT). PATsTAT contains bibliographical data relating to more than 100 million patent documents from leading industrialized and developing countries, as well as legal event data from more than 40 patent authorities contained in the EPO worldwide legal event data(INPADOC). The extracted subset is composed of 150,863 patent applications with priority years between 2007 and ***: Our observations indicate that even in more dynamic economies such as Portugal and spain, the participation of women per patent applications does not exceed 30%. Additionally, the distribution of female participation among institutional sectors and technological fields is consistent with previous studies in other regions and indicate a socio-cultural *** limitations: Unisex names were not considered and were counted as gender unknown, and patent applications for which no inventor information was available were discarded, but further effort of data analysis may provide more information about gender *** implications: While patents are imperfect variables of inventive step and therefore should be considered as a variable proxy of innovation, our findings may help to guide the implementation of policies for balancing gender participation in innovative activities, as well as instigating research into the issues causing divisive participation along gender ***/value: While there is a widespread effort into evaluating and improving the participation of groups recognized as minorities within state-of-the-art activities, research about women participation in the innovation sector is fragmente

关键词： Gender I beroamerica Patent statistic

Natural Mg silicates with different structures and morphologies: Reaction with K to produce K2MgsiO4 catalyst for biodiesel production

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第1期27卷 46-54页

作者： Fabiane carvalho Ballotin Mayra Nascimento sara silveira Vieira Alexandre carvalho Bertoli Ottávio Carmignano Ana Paula de carvalho Teixeira Rochel Montero Lago Departamento de Química Universidade Federal de Minas GeraisBelo HorizonteBrasil Doutorado Inovação/Mineradora Pedras Congonhas Universidade Federal de Minas Gerais31270-901 Belo Horizonte-MGBrazil

In this work, different magnesium silicate mineral samples based on antigorite, lizardite, chrysotile(which have the same general formula Mg3si2O5(OH)4), and talc(Mg3si4O10(OH)2) were reacted with KOH to prepare catalysts for biodiesel production. simple impregnation with 20 wt% K and treatment at 700–900°C led to a solid-state reaction to mainly form the K2MgsiO4 phase in all samples. These results indicate that the K ion can diffuse into the different Mg silicate structures and textures, likely through intercalation in the interlayer space of the different mineral samples followed by dehydroxylation and K2MgsiO4 formation. All the materials showed catalytic activity for the transesterification of soybean oil(1:6 of oil : methanol molar ratio, 5 wt% of catalyst, 60°C). However, the best results were obtained for the antigorite and chrysotile precursors, which are discussed in terms of mineral structure and the more efficient formation of the active phase K2MgsiO4.

关键词： silicate serpentinite lizardite antigorite talc chrysotile biodiesel