检索结果-南通市图书馆

Potential of Bamboo Species Guadua trinii and Guadua angustifolia for Nanocellulose Production

Journal of Renewable Materials 2024年第9期12卷 1541-1555页

作者： Agatha E.R.Prado Gárate Fernando E.Felissia María Cristina Area teresa Suirezs María Evangelina Vallejos Círculo de Investigación del Bambú Universidad Nacional Agraria La Molina(UNALM)Lima15026Perú Instituto de Materiales de Misiones(IMAM) Universidad Nacional de Misiones(UNaM)Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Facultad de Ciencias ExactasQuímicas y Naturales(FCEQYN)Programa de Celulosa y Papel(PROCyP)Posadas3300Argentina Instituto de Materiales de Misiones(IMAM) Universidad Nacional de Misiones(UNaM)Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Facultad de Ciencias Forestales(FCF)Eldorado3380Argentina

Non-traditional lignocellulosic materials are a significant resource for producing high-value products,including *** work studied the nanocellulose obtention from chemical pulps of the two fast-growing bamboo species,Guadua trinii,and Guadua *** pulps were produced by soda-anthraquinone(S)pulping from both autohydrolysis-pretreated(H)and unpretreated bamboo ***-pretreated(SHP)and unpretreated soda-anthraquinone(AQ)(SP)pulps were characterized by yield,Kappa number,alpha,beta,and gamma cellulose,degree of polymerization,water retention value,and *** nanocellulose was produced by a sequential chemical oxidation treatment(2,2,6,6-tetramethylpiperidine-1-oxyl,TEMPO reagent)and mechanical *** was characterized by carboxylic group content and *** results revealed that autohydrolysis pretreatment resulted in a higher hemicelluloses extraction in *** contrast,the pulping yield of unpretreated samples was higher for ***,and the soda-AQ pulps from this species exhibited better delignification than the autohydrolysis-pretreated *** crystallinity index values of the obtained pulps were high(>80%),and the alpha-cellulose contents were *** viscosities of the aqueous nanocellulose suspensions were higher for the nanocellulose solutions obtained from the unpretreated soda-AQ ***,nanocellulose from *** unpretreated soda-AQ pulps had a higher rate of carboxylic *** results of this work are significant in assessing the potential of both bamboo species as a source of high-value products within the biorefinery framework because the viscosities of the aqueous nanocellulose suspensions depend on the size and shape of *** has significant importance for industrial unit operations and potential applications.

关键词： Natural fiber Guadua angustifolia Guadua trinii soda-anthraquinone pulp nanocellulose

来源：

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

Unpaved rural roads as source areas of sediment in a watershed of the Brazilian semi-arid region

引用

International Journal of Sediment Research 2019年第5期34卷 475-485页

作者： teresa raque. lima farias Pedro Henrique Augusto Medeiros Joaquín Navarro-Hevia José Carlos de Araújo Federal Institute of Education Science and Technology of Ceará University of Valladolid Campus La Yutera Federal University of Ceará Department of Agricultural Engineering Campus do Pici

Approximately 80% of the road network in Brazil is unpaved and shows evidences of a high erosion potential. In the semi-arid Caatinga Biome in the northeast of the country, a monitoring programme has been done for two years in order to analyze runoff and sediment production from unpaved rural roadways and from embankments. Sediment production ranged from 0.30 to 0.92 Mg/ha yr, higher than in undisturbed areas, but generally lower than that reported for unpaved roads in other regions. However,this is a semi-arid area with low rainfall and runoff and, hence, with a limited hydrological connectivity and sediment production. Sediment production on an embankment with no vegetation was around ten times higher than on an embankment with vegetation. On the road surface, annual sediment production(normalized for gradient) in a section with traffic was three times higher than for a road surface without traffic. In addition, events that occurred after roadway maintenance activities generated peaks of sediment concentration of over 5000 mg/L. These results suggest that sediment production from roads and embankments with bare surfaces is at least one order of magnitude higher than in undisturbed catchment areas. Maintenance activity and vehicle traffic contribute to an increase in sediment availability and impact on the sediment concentration, but less intensely on sediment loads, which depend on the runoff magnitude of the events occurring after roadway maintenance. It was also found that the natural vegetation of the semi-arid region potentially captures sediment on roadway embankments; thereby playing an important role in breaking connectivity between the sediment flow from unpaved roads and the natural drainage system of the catchment.

关键词： Sediment production Caatinga vegetation Road maintenance Embankment

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Pseudo-discontinuum model to simulate hard-rock mine pillars

引用

Underground Space 2023年第4期11卷 81-95页

作者： Erick Ro genes Alessandra dos Santos Gomes Marcio Muniz de farias Leandro lima Rasmussen Faculty of Technology University of BrasiliaDF 70910-900BrasiliaBrazil

In this study,the pseudo-discontinuum modeling technique,called continuum Voronoi block model(CVBM),was applied to repre-sent the behavior of hard-rock pillars from underground mines subjected to high field *** CVBM’s ability to produce numerical results consistent with the observed behavior of pillars is demonstrated through the numerical analysis of a hypothetical case and a back analysis of the Creighton mine *** results show that the model can capture convergence displacements and explicitly show the formation of macro-fractures parallel to excavation walls,intact rock slabs,and V-shaped *** components are characteristics of brittle failure induced by highly stressed ground *** studies presented in this work confirm the CVBM as a convenient tool for the numerical modeling of intact rock pillars excavated in deep underground mines.

关键词： Brittle failure Spalling Bulking Voronoi tessellation

来源：

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

Fiber Laser Sensor Based on a Phase-Shifted Chirped Grating for Acoustic Sensing of Partial Discharges

引用

Photonic Sensors 2013年第1期3卷 44-51页

作者： Sanderson E. U. lima Rubem G farias Francisco M. ARAUJO Luis A. FERREIRA José L. SANTOS Vladimiro MIRANDA1 Orlando FRAZAO INESC Porto Rua do Campo Alegre 687 Porto 4169-007 Portugal Faeuldade de Engenharia da Computacāo Universidade Federal do Pará Belém Brasil Faculdade de Ciēncias da Universidade do Porto Rua do Campo Alegre 687 Porto 4169-007 Portugal Faculdade de Engenharia da Universidade do Porto Rua Dr. Roberto Frias s/n Porto 4200-465Portugal

Acoustic emission monitoring is often used in the diagnosis of electrical and mechanical incipient faults in the high voltage apparatus. Partial discharges are a major source of insulation failure in electric power transformers, and the differentiation from other sources of acoustic emission is of the utmost importance. This paper reports the development of a new sensor concept - a fiber laser sensor based on a phase-shifted chirped fiber grating - for the acoustic emission detection of incipient faults in oil-filled power transformers. These sensors can be placed in the inner surface of the transformer tank wall, not affecting the insulation integrity of the structure and improving fault detection and location. The performance of the sensing head is characterized and compared for different surrounding media： air, water, and oil. The results obtained indicate the feasibility of this sensing approach for the industrial development of practical solutions.

关键词： Transformer insulation partial discharges acoustic detection fiber laser sensors

来源：

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

Non-Isothermal Separation Process of Two-Phase Mixture Water/Ultra-Viscous Heavy Oil by Hydrocyclone

引用

Advances in Chemical Engineering and Science 2011年第4期1卷 271-279页

作者： Josedite Saraiva de Souza Fabiana Pimentel Macêdo farias Ramdayal Swarnakar Severino Rodrigues de farias Neto Antonio Gilson Barbos de lima 不详

Environmental agencies do not allow effluents, from the petroleum productions, which contain oil concentrations that exceed the amounts permitted by the regulations. In recent time heavy oil operating petroleum industries are generating oil/water mixture by products, which are difficult to separate. Industrially, hydrocyclone is generally used to separate oil from an oil/water mixture. This is due to its high performance of separation, low cost of installation and maintenance. In the present work, therefore, the thermal fluid dynamics of water/ultra-viscous heavy oil separation process in a hydrocyclone has been studied. A steady state mathematical model which simulates the performance of a non-isothermal separation process is presented. The Eulerian-Eulerian approach for the interface of the phases involved (water/ultra-viscous heavy-oil) is used and the two-phase flow is considered as incompressible, viscous and turbulent. For carrying out numerical solutions of the governing equations the CFX11? commercial code was used. Results of the behavior of the two-fluid flow inside the hydrocyclone and separation efficiency are presented and analyzed. The role of the average temperature of the fluid, oil droplet diameter and the fluid mixture inlet velocity on the separation efficiency of the hydrocyclone are verified.

关键词： Thermal Fluid Dynamics Hydrocyclone Two-Phase Flow Simulation Separation Efficiency

来源：

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

Self-care actions for the maintenance of the arteriovenous fistula:An integrative review

引用

International Journal of Nursing Sciences 2020年第3期7卷 369-377页

作者： Natália Ramos Costa Pessoa Laís Helena de Souza Soares lima Gutembergue Arag(a)o dos Santos Cecília Maria farias de Queiroz Fraz(a)o Clemente Neves sousa V(a)nia Pinheiro Ramos Federal University of Pernambuco Recife Brazil Center for Health Technology and Services Research Faculty of Medicine (CINTESIS) Porto University Nursing School of Porto Portugal

Objective:To identify self-care actions for the maintenance of arteriovenous fistula of renal ***:An integrative review study was conducted and literature were searched in Medline/PubMed,Scopus,CINAHL LILACS,BDENF and SciELO Library databases using the descriptors chronic renal insufficiency,arteriovenous fistula,self-care,and *** inclusion criteria were that the documents be written in Portuguese,English,and Spanish,full text available,published in the last five years,and that they address the research *** articles,theses,dissertations,editorials of nonscientific journals,and research studies that did not follow the necessary methodological rigor were *** were analyzed with the IRAMUJTEQ ***:Fifteen articles were selected and comprised the final *** classes of self-care actions emerged from the text segments analysis and grouped into three categories:(1)Self-care actions that maintain the arteriovenous fistula;(2)Self-care actions for the prevention and the monitoring of complications with arteriovenous fistula;(3)Self-care actions directed at the perioperative period of arteriovenous fistula ***:The results allowed us to identify important care for the maintenance of arteriovenous fistula *** self-care actions identified in this study can guide a nursing care policy for implementation with protocols that help identify problems related to self-care actions and,thus,subsidize the development of actions aimed at the renal ***,more studies with high levels of evidence that identify self-care actions with arteriovenous fistula and the factors involved in its implementation are needed.

关键词： Arteriovenous fistula Chronic renal insufficiency Health education Renal dialysis Self care

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Acute kidney injury in leptospirosis:Overview and perspectives

引用

Asian Pacific Journal of Tropical Medicine 2018年第10期11卷 549-554页

作者： Geraldo Bezerra da Silva Junior Nattachai Srisawat Gabriela Studart Galdino ênio Sima Macedo JoséReginaldo Pinto Geysa Maria Nogueira farias Renan lima Alencar Roberto da Justa Pires Neto Elvino JoséGuardao Barros Elizabeth De Francesco Daher Medical Sciences and Public Health and Graduate Programs School of Medicine Health Sciences Center University of Fortaleza Excellence Center for Critical Care Nephrology Division of Nephrology Department of Medicine Chulalongkorn University Collaborating CRISMA faculty member Department of Critical Care Medicine Univeristy of Pittsburgh School of Medicine Medical Sciences and Public Health Graduate Programs Department of Internal Medicine School of Medicine Federal University of Ceara Department of Internal Medicine School of Medicine Federal University of Rio Grande do Sul

Leptospirosis is a bacterial disease disseminated through the centuries in the whole world which causes symptoms that go from self-limited diseases to hemorrhagic manifestations and organ failure, including acute kidney injury(AKI), composing the severe disease known as the Weil's syndrome. Mortality rates varies according to the clinical presentation and usually increases when kidney injury is present, and is even higher in the setting of pulmonary hemorrhage. There are recent advances in the search for novel biomarkers of renal involvement and early detection of AKI in leptospirosis, as well as in its pathophysiology. We review in this article the clinical aspects of leptospirosis-associated AKI and the perspectives for future research.

关键词： Leptospirosis Acute kidney injury Perspectives Bacterial infections

来源：

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

The Igarape Weir decelerated transport of contaminated sediment in the Paraopeba River after the failure of the B1 tailings dam(Brumadinho)

引用

International Journal of Sediment Research 2023年第5期38卷 673-697页

作者： Daniela Patrícia Salgado Terêncio Fernando António Leal Pacheco Renato farias do Valle Junior Maytê Maria Abreu Pires de Melo Silva teresa Cristina Tarlé Pissarra Marília Carvalho de Melo Carlos Alberto Valera Luís Filipe Sanches Fernandes Inov4Agro/Centro de Investiga??o e Tecnologias Agroambientais e Biológicas Universidade de Trás-os-Montes e Alto Douro Centro de Química de Vila Real Universidade de Trás-os-Montes e Alto Douro Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista(UNESP) Via de Acesso Prof.Paulo Donato Castellane Instituto Federal do Triangulo Mineiro Campus Uberaba Laboratório de Geoprossessamento 5. Secretaria de Estado de Meio Ambiente e Desenvolvimento Sustentável Cidade Administrativa do Estado de Minas Gerais Rodovia Jo?o Paulo II 6. Coordenadoria Regional das Promotorias de Justi?a do Meio Ambiente das Bacias dos Rios Paranaíba e Baixo Rio Grande Rua Coronel Ant?nio Rios

The B1 dam of Co rrego do Feij～ao Mine, owned by Vale, S.A. mining company and located on the FerroCarv～ao stream, collapsed and injected 2.8 Mm3of clayey, silty, and sandy iron-and manganese-rich tailings into the Paraopeba River(Minas Gerais state, Brazil). The accident occurred on 25 January2019 and the tailings have been co-transported with coarser natural sediment since then, being partly trapped in the Igarape Weir reservoir located on the Paraopeba River nearly 45 km downstream the injection point. The general purpose of the current study was to model suspended sediment transport in the vicinity of the Igarape Weir aiming to assess the concomitant barrier effect imposed by this ***, the spatial distributions of suspended clay, silt, and very fine-grained sand fractions(CSS) of sediment were mapped around the Igarape Weir under low-flow(16 m3/s) and high-flow(5 to 10,000years return period stream discharge; 699—2,699 m3/s) regimes, using RiverFlow2D as the modelling tool. The concentrations of the various grain materials in the upstream and downstream sectors were quantified linking the barrier effect to concentration reductions in the direction of stream flow. It was also a study goal to calculate differences of iron and manganese concentrations in the sediment + tailings mixtures along the Paraopeba River. The study results showed reductions in the CSS between 6.6% and18%, from upstream to downstream of the Igarape Weir, related with backwater effects, free and submerged hydraulic jumps, bank sedimentation in periods of high flow, and streambed sedimentation controlled by channel sinuosity and tailings density. These reductions were accompanied by drops in the concentrations of iron and manganese present in the clay and silt fractions, which varied between 6% and42% under low flows and between 16% and 44% under high flows. Bank sedimentation was viewed as a potential threat to the riparian vegetation in the long-term. Dredging is the poten

关键词： Sediment transport Tailings dam break Metal contamination Hydrodynamic modelling RiverFlow2D Ratio concentration analysis

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Theoretical Evaluation of Two-Phase Flow in a Horizontal Duct with Leaks

引用

Advances in Chemical Engineering and Science 2013年第4期3卷 6-14页

作者： Morgana de Vasconcellos Araújo Severino Rodrigues de farias Neto Antonio Gilson Barbosa de lima Department of Chemical Engineering Center of Science and Technology Federal University of Campina Grande (UFCG Department of Chemical Engineering Center of Science and Technology Federal University of Campina Grande (UFCG) Department of Mechanical Engineering Center of Science and Technology Federal University of Campina Grande (UFCG) Campina Grande Brazil

The transport of oil and its derivates are done, mostly, by pipeline. The time to detect leaks has to be short for pre-venting big disasters in the nature and decreasing losses for industries. The techniques available for leak detection vary from visual inspection to the use of computational techniques such as mathematical modeling. This paper aims to study the fluid dynamics of two-phase flow (water-oil) in the pipe with leakage. The equations of the mass and momentum conservation are numerically solved by using the ANSYSCFX commercial code with the aid of a structured mesh of a horizontal pipe with three holes of leaks. The Eulerian-Eulerian model was adopted considering the oil as continuous phase and water as dispersed phase, and constant fluid properties. With profiles of pressure and volume fraction along the time in the pipe, the influence of leakage on the single-phase (oil) and two-phase (water-oil) was evaluated.

关键词： Two-Phase Flow Numerical Simulation Leakage Pipeline

来源：

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

Unsteady Fluidynamic Behavior of Gas Bubbles Flowing in Curved Pipes: A Numerical Study

引用

Advances in Chemical Engineering and Science 2012年第2期2卷 283-291页

作者： Jose Luis Gomes Marinho Ramdayal Swarnakar Severino Rodrigues de farias Neto Antonio Gilson Barbosa de lima Department of Chemical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil Department of Mechanical Engineering Center of Sciences and Technology Federal University of Campina Grande Campina Grande Brazil

Petroleum is considered as one of the factors for the development of a nation as well as a cause of economic and political conflicts around the world because of the diversity of products obtained with their derivatives such as fuel for automotives and aviation, and manufacturing plastic parts, among others. The crude petroleum (usually oil, water and gas) found in an underground reservoir is transported to the surface by pipes, and has drawn the attention of researchers because of the problems generated in the pipeline with particular attention to the loss of pressure, friction and bubbles. For a fluid flow in plug regime, where many of the bubbles formed coalesce and produce bigger ones of sizes almost equal to the pipe diameter (Taylor bubble), severe instability in the flow is caused. In this context, the objective of this research has been to study the Taylor bubble flow in curved ducts using the software CFX. Results of the transient effects of the air concentration on the bubble air volumetric fraction, of the viscosity on bubble format, and pipe angle of 90? on bubble symmetry are presented and interpreted.

关键词： Slug Flow Taylor Bubbles Curved Pipe CFD Oil Simulation

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：