检索结果-南通市图书馆

Effects of Solar UV Radiation on Materials Used in Agricultural Industry in Salta, Argentina: Study and Characterization

引用

Journal of Materials Science and Chemical Engineering 2014年第4期2卷 1-14页

作者： carlos cadena Delicia Acosta National Institute of Chemical Engineering INIQUI-CONICET Universidad Nacional de Salta Salta Argentina National Institute of Non-Conventional Energies INENCO-CONICET Universidad Nacional de Salta Salta Argentina

The current study presents the characterization of three types of materials after exposure to solar UV radiation. The selection of the materials is related to socio-economic aspects and rural activities in the northwest of Argentina (a.k.a. NOA). The objective was to establish a time parameter that allows estimating the durability of the materials according to their use. One of the materials is used as a protective cover (polyethylene film) of greenhouses, which are used for crop cultivation in the area. Another material is used in photovoltaic modules (PVMs), which are used to supply energy in isolated areas and the third material is sunscreen used by people that are exposed to UV radiation during rural activities. Degradation or deterioration of the materials was monitored using different spectroscopic assays: infrared was used to detect any structural changes in the material, X-rays were used for possible changes in the crystalline structure of the material, and spectral transmittance as this property is likely to be affected by changes in the structure of the material. The results showed that degradation of polyethylene seems to be related to the diminution in transparency and the loss of mechanical resistance with increasing exposure time. The decrease in transparency of one of the layers of a PVM caused a considerable decrease in the energy generated, whereas the sunscreens with a low sun protection factor (SPF) rapidly lost their protective properties and changed their photostability properties. Our results revealed a relationship between relative transmittance loss and exposure timse, which allows estimating the stability of different materials.

关键词： Polyethylene Films Photovoltaic Modules Sunscreen Characterization Degradation Effects Stability

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

Social Indicators in Preliminary Studies for the Installation of Solar Panels, Salta, Argentina

引用

Journal of Energy and Power Engineering 2014年第11期8卷 1869-1875页

作者： Emilce Ottavianelli Marcelo Ibarra carlos cadena Faculty of Sciences and Research Council National University of Salta Salta 4400 Argentina INIQUI (Institute for Chemical Industry) CONICET (National Scientific and Technical Research Council) Salta 4400 Argentina Public Prosecutor School Governance Salta 4400 Argentina INENCO (Research Institute of Non-Conventional Energy) CONICET (National Scientific and Technical Research Council)Salta 4400 Argentina

More than 10% of the population in Salta is regarded as rural. Many rural areas suffer a shortage of energy, and consequently, possibilities of social and economic development of the inhabitants become reduced. The activation of renewable energy sources in these areas presents inhabitants the advantages to generate their own energy. Dispersed rural communities create small electricity demands that are not considered by suppliers, because they are not profitable. Although thus far, feasibility analyses to install photovoltaic or thermal solar collectors are based on technical reasons, it seems more convenient that, in the future, projects for the installation of technology based on renewable energy should consider social indicators. As a preliminary step to field work is proposed in this paper using an equation that allows us to obtain a value of＂social index＂. With this analysis and the current survey accompanied by the local people, knowledge will be obtained of the real needs of these rural communities. The results show that there is a variation that would allow a classification or ordering of localities. To validate the results obtained is proposed as the next step to perform field work in each of the localities.

关键词： Solar energy social index rural community.

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

cSi Photovoltaic Modules, Main Degradation Factors Case Study: La Puna (Argentina)

引用

Engineering（科研） 2016年第6期8卷 371-385页

作者： María Teresa Montero Larocca carlos Alberto cadena María Julia Luisa Tamasi INENCO Instituto de Investigaciónen Energía No Convencional Salta Argentina CNEA Comisión Nacional de Energía Atómica Salta Argentina

This paper presents an analysis of the power loss of a set of photovoltaic modules exposed for more than fifteen years to solar radiation and other environmental factors. The study covered modules installed in 1989 and concluded with modules installed in 2004 (to 2009). Many of them were located in places high above the sea level and with high values of ultraviolet radiation. It is known that this power loss is caused by various factors: loss of optical properties of the protective glass, loss of transmittance of the encapsulation material (EVA), increase in series resistance, decrease in shunt resistance as well as other factors not analyzed in this study. The contribution of each of these factors to the power loss is measured and discussed in this analysis.

关键词： Degradation Shunt-Series Resistance Loss Transmittance

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

Temporal-spatial segregation among hummingbirds foraging on honeydew in a temperate forest in Mexico

引用

Current Zoology 2011年第1期57卷 56-62页

作者： carlos LARA Vanessa MARTINEZ-GARCIA Raul ORTIZ-PULIDO Jessica BRAVO-cadena Salvador LORANCA Alex CORDOBA-AGUILAR Laboratorio de Ecologfa de la Conducta Centro Tlaxcala de Biologfa de la Conducta UAT-UNAM Km 1.5 carretera Tlaxcala- Puebla s/n Colonia Xicohtencatl Apdo. Postal 262 Tlaxcala Tlaxcala 90070 Mexico Laboratorio de Ecologfa de Poblaciones. Centro de Investigaciones Biologicas. Universidad Autonoma del Estado de Hidalgo Mexico Departamento de Quimica y Biologia. Universidad de las Ameficas-Puebla. Cholula Puebla Mexico Departamento de Ecologfa Evolutiva. lnstituto de Ecologfa Universidad Nacional Autonoma de Mexico Distrito Federal Mexico

Spatial and temporal variation in interactions between hummingbirds and plants have often been examined, and hummingbirds and insects are known to indirectly interact in networks of nectar plants. In a highland temperate forest in Hidalgo, Mexico some oak trees were heavily infested by honeydew-producing insects （family Margarodidae, tribe Xylococcini, genus Strigmacoccus） and the honeydew was consumed by hummingbirds. Here using survival analysis we investigate how the honey- dew produced by dense populations of these margarodids is temporally and spatially partitioned by hummingbirds. We also measured the availability and quality of honeydew exudates, and then we recorded the time until a bird visited and used such re- sources. Four hummingbird species consumed this resource （Atthis eloisa, Hylocharis leucotis, Colibri thalassinus and Eugenes fulgens）. Data from 294 hours of observation on seven focal trees suggested temporal and spatial segregation among visiting birds according to body size and territorial behavior during the most honeydew-limited time. Hummingbird species differed in the dally times they foraged, as well as in the location where honeydew-producing insects were visited on the trees. Temporal and spatial segregation among hummingbird species is interpreted as an adaptation to reduce the risk of aggressive encounters. This may facilitate multispecies coexistence and allow these birds to exploit honeydew more effectively

关键词： Honeydew Hummingbirds Mexico Nectarivory Niche partitioning

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

Hierarchical dispatch of multiple microgrids using nodal price:an approach from consensus and replicator dynamics

引用

Journal of Modern Power Systems and Clean Energy 2019年第6期7卷 1573-1584页

作者： Miguel A.VELASQUEZ Oscar TORRES-PEREZ Nicanor QUIJANO Angela cadena Department of Electrical and Electronics Engineering Universidad de los AndesBogotaColombia

A hierarchical approach for the energy management of geographically close microgrids connected through a dedicated AC power network is proposed in this *** proposed approach consists of a two-layer energy management system(EMS)for networked *** the lower layer,each micro grid solves its own economic dispatch problem through a distributed model predictive control approach that respects capacity limits and ramp-rate constraints of distributed *** the upper layer,the energy trading in the network of microgrids decides how to optimally trade the energy based on the marginal cost information from the lower layer in order to improve global optimization objectives,e.g.,social *** order to solve the trading problem,a consensusbased algorithm and a replicator dynamics algorithm are proposed assuming that the marginal cost function of the microgrid is known and *** is shown that both algorithms converge to the same solution,which is equivalent to the minimization of operation *** consensus-based algorithm is extended in order to tackle more general marginal cost functions and trading network ***,the effect of ramp constraints and network limits is *** show the effectiveness of the proposed algorithms for three interconnected microgrids with different characteristics.

关键词： Consensus Economic dispatch Hierarchical control Networked microgrids Ramp limits Replicator dynamics

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

Evaluation of bias on the assessment of diet breadth of herbivorous insects using molecular methods

引用

Insect Science 2017年第2期24卷 194-209页

作者： Gissela De la cadena Anna Papadopoulou Jean-Michel Maes Jesus Gomez-Zurita Animal Biodiversity and Evolution Institut de Biologia Evolutiva (CSIC-Univ. Pompeu Fabra) Barcelona Spain Department of Integrative Ecology Estacion Biologica de Donana (EBD-CSIC) Seville Spain Museo entomologico de Leon Leon Nicaragua

The interactions between herbivores and their host plants play a key role in ecological processes. Understanding the width and nature of these interactions is funda- mental to ecology and conservation. Recent research on DNA-based inference of trophic associations suggests that the host range of phytophagous insects in the tropics may be wider than previously thought based on traditional observation. However, the reliability of molecular inference of ecological associations, still strongly dependent on PCR and thus exposed to the risk of contamination with environmental DNA, is under debate. Here, we explored alternative procedures to reduce the chance of amplification of external, nondiet DNA, including surface decontamination and analysis of mid/hind guts, comparing the results with those obtained using the standard protocol. We studied 261 specimens in eight species of Neotropical Chrysomelidae that yielded 316 psbA-trnH intergenic spacer sequences （cpDNA marker of putative diets） from unique and multiple-band PCR results. The taxonomic identity of these sequences was inferred using the automated pipeline BAGpipe, yielding results consistent with 31 plant families. Regardless of the proto- col used, a wide taxonomic spectrum of food was inferred for all chrysomelid species. Canonical Correspondence Analysis using these data revealed significant differences at- tributed mainly to species （expectedly, since they represent different ecologies）, but also to treatment （untreated vs. cleaned/gut samples） and PCR results （single vs. multiple bands）. Molecular identification of diets is not straightforward and, regardless of the species＇ niche breadth, combining approaches that reduce external contamination and studying multiple individuals per species may help increasing confidence in results.

关键词： food-webs gut content insect plant interaction molecular ecology molec-ular taxonomy psbA-trnH intergenic spacer

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

Influence of Vanadium Additions on the Performance of Mo<sub>3</sub>Si

引用

Materials Sciences and Applications 2021年第7期12卷 345-352页

作者： I. Rosales-cadena Center for Research in Engineering and Applied Sciences Cuernavaca Mexico

Several molybdenum silicides based alloys were produced by arc cast method with different vanadium additions. The microstructures revealed mainly single phase in samples with precipitation of second phases segregated to the grain boundaries. Lattice parameter and density measurements with different V concentrations have been correlated with lattice distortion. Mechanical properties studies were carried out, showing a decreasing behavior in microhardness while fracture toughness value increases at intermediate concentrations. Results indicated that vanadium alloying produces a significant effect on grain growth behavior and second phase precipitation.

关键词： Silicides Indentation Hardness Fracture Toughness Lattice Parameter

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

Severe COVID-19 patients exhibit an ILC2 NKG2D^(+) population in their impaired ILC compartment

引用

Cellular & Molecular Immunology 2021年第2期18卷 484-486页

作者： Alejandra Gomez-cadena Laurie Spehner Marie Kroemer Myriam Ben Khelil Kevin Bouiller Grégory Verdeil Sara Trabanelli Christophe Borg Romain Loyon Camilla Jandus Department of Pathology and Immunology University of GenevaGenevaSwitzerlandand Ludwig Institute for Cancer ResearchLausanneSwitzerland University of Bourgogne Franche-Comté INSERMEFS BFCUMR1098RIGHT Interactions Greffon-Hôte-Tumeur/Ingénierie Cellulaire et GéniqueF-25000BesançonFrance Department of Pharmacy University Hospital of BesançonF-25000BesançonFrance Department of Infectious Disease University Hospital of BesançonF-25000BesançonFrance UMR-CNRS 6249 Chrono-Environment UniversitéBourgogne Franche-ComtéF-25000BesançonFrance Department of Oncology UNIL-CHUVUniversity of Lausanne1066EpalingesSwitzerland Department of Medical Oncology University Hospital of BesançonF-25000BesançonFrance

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is responsible for the current COVID-19 disease *** some patients,the symptoms are mild,and a fraction of SARS-CoV-2-infected individuals develop severe illness with a high fatality rate due to lung damage and acute respiratory distress syndrome.1 Innate lymphoid cells(ILCs)are a recently identified type of effector immune cells that rapidly sense environmental stimuli and participate in early immune responses by promptly secreting large amounts of cytokines.2 The ILC2 subpopulation was shown to mediate Type 2 responses and to recruit eosinophils during viral lung infections upon the release of alarmins(e.g.,IL-33)by damaged epithelial cells.3,4,5 ILC2s were also shown to participate in the termination of inflammatory responses and tissue repair by amphiregulin *** addition,ILC2s are critical in the early phases of allergic lung inflammation,including that induced by the protease allergen papain.6 Based on the essential function of the papain-like protease PLpro in regulating SARS-CoV-27(Fig.1a)and the severe lung damage caused by this virus,we sought to investigate the potential involvement of ILC2s in immune responses to COVID-19.

关键词： impaired patients acute

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

Dispersion of niquel on the microstructure in magnesium based alloys for hydrogen storage

引用

Journal of Magnesium and Alloys 2013年第4期1卷 292-296页

作者： A.A.Zaldıvar-cadena I.Dıaz-Pena J.G.Cabanas-Moreno Universidad Autonoma de Nuevo Leon Av.Universidad s/nFacultad de Ingenierıa CivilSan Nicolas de los Garza N.L.C.P.66451Mexico Instituto Politecnico Nacional UPALMCol.LindavistaC.P.07338 Mexico D.F.Mexico

Mg–Xwt.%Ni(X=5 and 20)alloys have been prepared by mechanical alloying using milling times of 15 and 30 h in a planetary ball milling to know the effects of magnesium with the addition of Ni as catalyst,dispersion on the microstructure,area surface and the efficiency of hydrogen ***-EDS,XRD and ImageJ^(■)software have been used to characterize the microstructure and chemical composition of the *** experiments were performed as batch-type tests at 200,250 and 300℃ under 2 MPa H2 pressure during 30 *** experiments resulted in varying amounts of MgH2 in the hydrided powders depending on composition and hydriding *** best results point to an optimum Ni dispersion,which in turn depends on Ni content and milling time.

关键词： Hydrogen storage Magnesium Niquel Alloy Characterization

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

Blood Flow Simulation in the Femoral Artery

引用

Journal of Electronic Science and Technology 2018年第3期16卷 269-279页

作者： Camilo A.Naranjo Andrés F.Villa Juan C.Vélez Ricardo A.Prato Alberto J.cadena Juan P.Tello IPATEC Institute CONICETBariloche R8400 Integra IT Bogotá 602 the Electronic and Electric Engineering Department Universidad del NorteBarranquilla 1569 the Institute of Mathematics Universidad de AntioquiaMedellin 050010 the Cardiology Department Clínica de la CostaBarranquilla 080020

This paper presents the development of the blood flow simulation in two dimensions over the real geometry of the femoral artery. The Navier-Stokes equations are solved using the finite element method, to obtain the distributions of the blood pressure and flow velocity in multiple instants of time and different places of the femoral artery and thus determine the current condition of the blood vessels. The velocity field shows a laminar behavior,where, the velocity is higher in the center of the artery and decreases as the blood flow approaches artery walls. In spite of all artery and blood flow properties not being considered, the values of pressure and velocity obtained are within the normal ranges. Finally the model is used to verify if there exist irregularities in the blood flow in both healthy subjects and sick patients.

关键词： Blood flow femoral artery finite elements Navier-Stokes pressure velocity

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

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：