检索结果-南通市图书馆

Corrosion behavior of electron beam processed AZ91 magnesium alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2020年第4期8卷 1314-1327页

作者： Fatemeh Iranshahi Mohammad Bagher Nasiri fernando Gustavo Warchomicka Christof Sommitsch Institute of Materials Science Joining and FormingGraz University of TechnologyKopemikusgasse 24/1Graz 8010Austria

The increasing use of light alloys owing to their high performance makes magnesium alloys very attractive for the use in automotive and biomedical ***,it is well known that magnesium and its alloys have poor corrosion resistance in different atmospheric and aqueous *** a means of improving corrosion resistance through the microstructure modification,electron beam processing(EBP)was applied on the as-cast AZ91 magnesium *** evaluate the microstructure influence on the corrosion-resistant,the EB processed samples underwent a solution heat treatment and an artificial aging heat *** different obtained microstructures were investigated by standard microscopy and electrochemical corrosion tests to evaluate the microstructure and its effects on the corrosion resistance of AZ91 *** EBPed specimens show a significant microstructure refinement and homogenous distribution ofβ-phase at the grain boundaries surrounded by supersaturatedα-Mg which acts as a barrier against *** electrochemical corrosion test of the samples immersed in 3.5 wt%NaCl after 4 weeks indicates that the EBP improves the corrosion resistance of the alloy due to the nobler corrosion potential of supersaturated a-Mg and more stable protective hydroxide films compared to the heat-treated and as-cast conditions.

关键词： Magnesium alloys Electron beam processing Corrosion AZ91 Microstructure Grain refinement.

Internal anal sphincter augmentation and substitution

在线全文

学校读者我要写书评

暂无评论

Gastroenterology Report 2014年第2期2卷 106-111页

作者： fernando de la Portilla Unidad de Gestion Clinica de Cirugia General y del Aparato Digestivo Instituto de Biomedicina de Sevilla(IBIS)SevilleSpain

There is an increasing recognition of the importance of internal anal sphincter(IAS)dysfunction presenting as passive faecal *** problem may manifest after anal sphincterotomy or following the more minimally invasive operations for haemorrhoids,as well as with advancing *** of the poor results of IAS plication and the beneficial outcomes with peri-urethral bulking agents in urology,these materials have been developed for use in IAS *** review outlines the basic purported mechanisms of action,defining the materials in clinical use,their methods of deployment,complications and reported *** is still much that is unknown concerning the ideal agent or the volume and the technique of deployment,which will only be answered by powerful,prospective,randomized,controlled *** specific role of autologous stem cells designed to regenerate the sphincters in cases of functional impairment or muscle loss is yet to be seen.

关键词： faecal incontinence internal anal sphincter dysfunction internal anal sphincter augmentation bulking agents

Polymer Sensitized Quasi Solid-State Photovoltaic Cells Using Derivatives of Polythiophene

维普期刊数据库评论

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 Materials Science & Technology 2006年第6期22卷 811-816页

作者： G.K.R.Senadeera J.M.R.C.fernando Institute of Fundamental Studies Hantane RoadKandySri Lanka Institute of Fundamental Studies Hantane RoadKandySri Lanka Postgraduate Institute of ScienceUniversity of PeradeniyaPeradeniyaSri Lanka

Substituted thiophene sensitized, nanocrystalline TiO2-based quasi solid-state solar cells were fabricated by using either poly （3-thiophene acetic acid）（P3TAA） or a copolymer with poly （3-thiophene acetic acid）-poly （hexyl thiophene）（P3TAA-PHT） polymers and copper iodide （Cul） as a hole conducting material together with an ionic liquid 1-ethyl-3-methylimidazolium bis （trifluoromethylsulfonyl） amide and lithium bis （triflu- oromethanesulfone） imide as additives for charge transport promotion. Dramatic enhancements in the cell performances were observed with the additives in Cul. While the cell sensitized with P3TAA generated a short-circuit photocurrent of -1.45 ***^-2, an open-circuit photovoltage of -345 mV with a total power conversion efficiency of -0.3% under simulated full sunlight of 100 mW-cm^-2 （air mass： 1.5）, the cell sensitized with copolymer P3TAA-PHT delivered -0.25% efficiency under the same conditions with -1.23 mA-cm^-2 as photocurrent and -371 mV as photovoltage.

关键词： Solar cells Polymers Titanium dioxide

Behavior of diatomaceous soil in lacustrine deposits of Bogota, Colombia

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 367-379页

作者： Bernardo Caicedo Cristhian Mendoza fernando López Arcesio Lizcano Department of Civil and Environmental Engineering Universidad de Los AndesBogotáColombia Department of Civil Engineering Universidad Nacional de Colombia Sede ManizalesManizalesColombia Ecole Centrale Paris Laboratoire MSSMat-UMR CNRS 8579ParisFrance SRK Consulting VancouverCanada

This work presents a study on the behaviors of diatomaceous soils. Although studies are rarely reported on these soils, they have been identified in Mexico City, the Sea of Japan, the northeast coast of Australia,the equatorial Pacific, and the lacustrine deposit of Bogota(Colombia), among other locations. Features of this kind of soil include high friction angle, high initial void ratio, high compressibility index, high liquid limit, and low density. Some of these features are counterintuitive from a classical soil mechanics viewpoint. To understand the geotechnical properties of the diatomaceous soil, a comprehensive experimental plan consisting of more than 2400 tests was performed, including physical tests such as grain size distribution, Atterberg limits, density of solid particles, and organic matter content; and mechanical tests such as oedometric compression tests, unconfined compression tests, and triaxial *** tests were complemented with scanning electron microscope(SEM) observations to evaluate the microstructure of the soil. The test results show that there is an increase in liquid limit with increasing diatomaceous content, and the friction angle also increases with increasing diatomaceous content. In addition, several practical correlations were proposed for this soil type for shear strength mobilization and intrinsic compression line. Finally, useful correlations were presented, such as the relationship between the state consistency and the undrained shear strength, the friction angle and the liquid limit, the void ratio at 100 kPa and the liquid limit, the plasticity index and the diatomaceous content, among others.

关键词： Diatomaceous soil Soft soils Compressibility Friction angle Natural soil

Low-Cost Tiled Display System Architecture with Dynamic Web-Based Management

在线全文

学校读者我要写书评

暂无评论

China Communications 2022年第10期19卷 143-168页

作者： Daniel Marfil fernando Boronat F.Javier Pastor Anna Vidal Communications Department Gandia CampusUniversitat Politecnica de ValenciaCalle Paraninfo146730Grao de GandiaValencia(Spain) Drawing Department Gandia CampusUniversitat Politecnica de ValenciaCalle Paraninfo146730Grao de GandiaValencia(Spain) Applied Mathematics Department Gandia CampusUniversitat Politecnica de ValenciaCalle Paraninfo146730Grao de GandiaValencia(Spain)

In this paper, a scalable hardware and software architecture for tiled display systems (a.k.a. videowalls), which can be implemented by using low-cost devices, together with a dynamic web-based management and configuration service are proposed. It has been designed to support both stored and live broadcast/broadband content, in mosaic or warp distributions. The displays and devices can be dynamically configured via web in different ways: the displays can create a single display of a larger size;or they can be configured in a customized way in order to playout different media contents in different display combinations. As display renderers, low-cost devices are proposed as the main hardware element to obtain affordable videowall systems. As a proof of concept, two prototypes have been implemented, including an accurate synchronization mechanism based on a Master/Slave control scheme and aggressive and smooth playout adjustment techniques. To evidence the good performance of the prototypes and configuration service, both objective and subjective evaluations have been conducted regarding synchronization accuracy and usability. On the one hand, the mean values of the asynchronies between the video playout processes in each display are kept below 25ms (i.e., frame accuracy). On the other hand, the obtained usability score in the System Usability Scale (SUS) test has been 88.65, which is considered as excellent.

关键词： AMP media synchronization multi-screen playout adjustment tiled displays videowall

Short-term effect of physical activity on sleep health:A population-based study using accelerometry

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2022年第5期11卷 630-638页

作者： Andrea Wendt Inácio Crochemore M.da Silva Helen Goncalves Ana Menezes fernando Barros fernando C.Wehrmeister Post-graduate Program in Epidemiology Federal University of PelotasPelotas 96020-220Brazil

Background:Regular physical activity(PA) is an important behavior in improving sleep ***,the short-term effects of PA on sleep are still *** study aimed to verify the effect of different intensities of PA practiced in different periods of the day on the subsequent sleep night in a population-based cohort of young ***::Prospective analyses were conducted for PA performed during the day and its effect on the following sleep night using data from the22-year follow-up of the 1993 Pelotas Birth Cohort in Brazil(mean age of participants-22.6 years).Wrist-worn accelerometry was usedto measure both PA and sleep *** intensity,we analyzed the sleep effect of light PA(LPA),moderate PA,and vigorous PA,stratified by *** variables were sleep time window(STW;the difference between sleep onset and sleep end),total sleep time(TST;the sum of minutes classified as sleep in STW),and sleep percent(SP;SP=(TST/STW);expressed in percentage).We performed generalized estimating equations using Stata ***::The means of STW,TST,and SP were 443.6 min/day,371.1 min/day,and 84%,*** spent in moderate PA and vigorous PA in the morning and afternoon was not associated with sleep *** men,10 min/day of morning LPA increased TST by2.56 min/*** women,10 min/day of morning LPA increased SP by 0.15 percentage *** LPA also increased SP by 0.09 percentage points for *** PA seems to have an inverse effect on sleep variables for any intensity and both ***::The effect of PA on sleep health is intrinsically related to the period of the day in which it is *** effect magnitude is different between *** better sleep health,it is preferable that PA be performed during the day.

关键词： Accelerometer Exercise Physical activity Population-based study Sleep health

The role of behavioral changes and prompt treatment in the control of STIs

在线全文

学校读者我要写书评

暂无评论

Infectious Disease Modelling 2019年第1期4卷 1-10页

作者： fernando Saldaňa Ignacio Barradas CIMAT Guanajuato Gto36000 Mexico

In this paper,we study general recovery functions and treatment in the dynamics of an SIS model for sexually transmitted infections with nonzero partnership *** is shown how partnership dynamics influences the predicted prevalence at the steady state and the basic reproduction ***'s indices are used to evaluate the contribution of model parameters to the overall variance of R *** recovery functions studied here take into account that society's capacity to provide treatment is limited when the number of infected individuals is *** analysis is used to establish a relationship between an alert level of prevalence and the minimum recovery time that guarantees the eradication of the *** also show that a backward bifurcation can occur when there are delays in the treatment of infected individuals.

关键词： Recovery function Pair formation Sensibility analysis Behavioral interventions Sexually transmitted infections

Vision-based fatigue crack detection using global motion compensation and video feature tracking

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2023年第1期22卷 19-39页

作者： Rushil Mojidra Jian Li Ali Mohammadkhorasani fernando Moreu Caroline Bennett William Collins Department of Civil Environmental and Architectural EngineeringThe University of KansasLawrenceKansasUSA Department of Civil Construction and Environmental EngineeringUniversity of New MexicoAlbuquerqueNew MexicoUSA

Fatigue cracks that develop in civil infrastructure such as steel bridges due to repetitive loads pose a major threat to structural *** being the most common practice for fatigue crack detection,human visual inspection is known to be labor intensive,time-consuming,and prone to *** this study,a computer vision-based fatigue crack detection approach using a short video recorded under live loads by a moving consumer-grade camera is *** method detects fatigue crack by tracking surface motion and identifies the differential motion pattern caused by opening and closing of the fatigue ***,the global motion introduced by a moving camera in the recorded video is typically far greater than the actual motion associated with fatigue crack opening/closing,leading to false detection *** overcome the challenge,global motion compensation(GMC)techniques are introduced to compensate for camera-induced *** particular,hierarchical model-based motion estimation is adopted for 2D videos with simple geometry and a new method is developed by extending the bundled camera paths approach for 3D videos with complex *** proposed methodology is validated using two laboratory test setups for both in-plane and out-of-plane fatigue *** results confirm the importance of motion compensation for both 2D and 3D videos and demonstrate the effectiveness of the proposed GMC methods as well as the subsequent crack detection algorithm.

关键词： global motion compensation fatigue crack detection computer vision parallax effect distortion induced fatigue crack video stabilization camera motion in-plane fatigue crack out-of-plane fatigue crackanalysis

Robust state feedback for uncertain 2-D discrete switched systems in the Roesser model

在线全文

学校读者我要写书评

暂无评论

Journal of Control and Decision 2021年第3期8卷 331-342页

作者： Khalid Badie Mohammed Alfidi fernando Tadeo Zakaria Chalh Engineering Systems and Applications LaboratoryNational School of Applied SciencesFezMorocco Institute of Sustainable Processes and Industrial Engineering SchoolUniversity of ValladolidValladolidSpain

The design of robust H_(∞)controllers is considered here for a class of two-dimensional(2-D)discrete switched systems described by the Roesser model with polytopic *** focuses on the design of a switched state feedback controller,which guarantees the robust asymptotic stability and a prescribedH_(∞)performance for the closed-loop *** using multiple parameter-dependent Lyapunov functionals,and introducing some switched free-weighting matrices,a new sufficient condition for the robust H_(∞)performance analysis of uncertain 2-D discrete switched systems is ***,the design of switched state feedback controller is proposed in terms of linear matrix inequalities(LMIs).Illustrative examples are given to illustrate the effectiveness of the developed theoretical results.

关键词： 2-D discrete switched systems polytopic uncertainties robust H∞control linear matrix inequalities(LMIs)