检索结果-南通市图书馆

Wavelet-based deconvolution of ultrasonic signals in nondestructive evaluation

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 Zhejiang University-Science A(Applied Physics & Engineering) 2006年第10期7卷 1748-1756页

作者： herrera Roberto Henry orozco Rubén RODRIGUEZ Manuel Department of Informatics University of Cienfuegos Cienfuegos 59430 Cuba CEETI Central University of Las Villas Santa Clara 54830 Cuba Department of Physics Central University of Las Villas Santa Clara 54830 Cuba

In this paper, the inverse problem of reconstructing reflectivity function of a medium is examined within a blind deconvolution framework. The ultrasound pulse is estimated using higher-order statistics, and Wiener filter is used to obtain the ultrasonic reflectivity function through wavelet-based models. A new approach to the parameter estimation of the inverse filtering step is proposed in the nondestructive evaluation field, which is based on the theory of Fourier-Wavelet regularized deconvolution (ForWaRD). This new approach can be viewed as a solution to the open problem of adaptation of the ForWaRD framework to perform the convolution kernel estimation and deconvolution interdependently. The results indicate stable solutions of the esti- mated pulse and an improvement in the radio-frequency (RF) signal taking into account its signal-to-noise ratio (SNR) and axial resolution. Simulations and experiments showed that the proposed approach can provide robust and optimal estimates of the reflectivity function.

关键词： Blind deconvolution Ultrasonic signals processing Wavelet regularization

Are Polymers Toxic？ Case Study： Environmental Impact of a Biopolymer

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

Journal of Environmental Science and Engineering(B) 2017年第3期6卷 121-126页

作者： Giovanna Mercado Martha Dominguez israel herrera Rosa Maria Melgoza Environmental Engineering and Sustainable Technologies Faculty of Chemical Sciences and Engineering Autonomous University of the State of Morelos Cuernavaca 62209 Mexico Faculty of Chemical Sciences and Engineering Center for Research in Engineering and Applied Sciences Autonomous University of the State of Morelos Cuernavaca 62209 Mexico Center for Energy Environmental and Technological Research Madrid 28040 Spain

In this paper, the analysis of the environmental impacts of a biopolymer based on starch is presented. These impacts were calculated from a cradle to gate LCA （Life Cycle Assessment）, based on UNEEN ISO 14040：2006 and UNEEN ISO 14044, using as functional unit 1 kg of produced biomaterial. The impact categories analyzed were global wanning, ozone depletion, acidification and eutrophication. The results indicate that the electricity causes the highest impacts in the global warming and ozone depletion categories, but compared to synthetic polymers, the emissions are low. Finally, in the case of eutrophication, the impacts are similar to other biopolymers but higher in comparison with petroleum-based polymers like HDPE （High Density Polyethylene）, LDPE （Low Density Polyethylene）, PP （Polypropylene）, PS （Polystyrene） and PET （Polyethylene Terephthalate）.

关键词： Polymer biopolymer LCA environmental impacts.

Photo timeline of localized cutaneous leishmaniasis,Colombia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Infectious Medicine 2023年第1期2卷 63-65页

作者： Alvaro A.Faccini-Martínez Abraham Katime Zuniga Beatriz Elena orozco Sebá María-Joséherrera-Bedoya Fundación Universitaria de Ciencias de la Salud–FUCS Research InstituteBogotáColombia Servicios y Asesorías en Infectología–SAI BogotáColombia Hospital Militar Central Servicio de InfectologíaBogotáColombia Universidad del Magdalena School of MedicineSanta MartaMagdalenaColombia Universidad del Norte School of MedicineBarranquillaAtlánticoColombia Fundación Hospital Universidad del Norte Department of DermatologySoledadAtlánticoColombia Fundación Hospital Universidad del Norte Department of PathologySoledadAtlánticoColombia

Dear Editor,New World cutaneous leishmaniasis is a vector-borne neglected tropical disease caused by infection with protozoan parasites of the genus Leishmania;most of them included in the subgenus Viannia,which are transmitted by the bites of infected female phlebotomine sandflies[1].In Colombia *** and *** are the most frequent species associated with cutaneous leishmaniasis[2].The spectrum of New World cutaneous leishmaniasis includes single or multiple,localized,cutaneous ulcers;diffuse cutaneous leishmaniasis;disseminated cutaneous leishmaniasis;and mucosal leishmaniasis[3].

关键词： leishmaniasis cutaneous infection

Renewable Diesel Fuel from Processing of Vegetable Oil in Hydrotreatment Units: Theoretical Compliance with European Directive 2009/28/EC and Ongoing Projects in Spain

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Smart Grid and Renewable Energy 2010年第2期1卷 70-73页

作者： Daniel Garraín israel herrera Carmen Lago Yolanda Lechón Rosa Sáez 不详

Oil hydrotreating units in refineries are aimed at reducing the sulfur content of fuels to accomplish standard par-ticular specifications. However, this process is currently one of the best available technologies to produce biofuels from vegetable oil in a refinery. Vegetable oils can be processed or co-processed in these units if several adaptations are performed, so some properties could be improved in comparison with conventional fuel such as density and cetane number. This study highlights the theoretical greenhouse gases (GHG) emissions (using a life cycle assessment–LCA-approach) of a hydrotreated vegetable oil (HVO) from bibliographical data. Results were compared with other biofuel production processes, such as those obtained by transesterification of vegetable oil (FAME, fatty acid methyl ester). It has also been included the comparison with conventional fossil diesel as a benchmark in order to assess the theoretical compliance with GHG savings proposed in European Directive 2009/28/EC. Finally, ongoing projects and future perspectives in Spain are mentioned.

关键词： Hydrotreated Vegetable Oil Fatty Acid Methyl Ester GHG Emissions Savings Directive 2009/28/EC Renewable Diesel Fuel

Environmental Issues of a Marine Protected Area in a Tectonic Estuary in the Tropical Eastern Pacific:Uramba(Malaga Bay Colombia):Context,Biodiversity,Threats and Challenges

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 Water Resource and Protection 2013年第11期5卷 1037-1047页

作者： Jaime Ricardo Cantera Kintz Edgardo Londono-Cruz Luz Marina Mejia-Ladino Leonardo herrera-orozco Carlos Andres Satizabal Natalia Uribe-Castaneda Research Group in Estuaries and Mangroves of Colombian Pacific Departamento de BiologiaUniversidad del ValleCaliColombia Research Group in Taxonomy Systematic and Marine EcologyInstituto de Investigaciones Marinas y Costeras“Jose Benito Vives de Andreis”Santa MartaColombia

The environmental protection of tropical marine and coastal areas faces different challenges due to the diversity of aspects related to these areas, which include natural, social and economical issues. Despite these challenges, efforts for the protection of these areas are urgent nowadays because of the dramatical increase of human related threats like habitat destruction and population growth. Malaga Bay (MB) is a tectonic estuarine system located in Panama Bight (central region of the Colombian Pacific coast), which due to its origin shows important environmental characteristics of few sites in the Tropical Eastern Pacific (TEP) match. For these reasons, the government of Colombia declared in 2010, the bay’s marine area as a Marine National Natural Park in order to preserve its unique estuarine marine biodiversity. Despite this measure, MB presents several conditions that make environmental protection a very difficult task. In this paper, we present the geographical context, biodiversity and natural resources, environmental threats, the complexity of economic and social context, and the institutional and legal context of MB, to exemplify the difficulty that the protection of marine areas face in the TEP.

关键词： Protected Marine Areas Resources Conservation Estuaries Tropical Eastern Pacific

Non-Linear Analysis of Energy Absorption Systems under Impact Loads through FEM

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 Mechanics Engineering and Automation 2012年第8期2卷 487-494页

作者： Elias Rigoberto Ledesma-orozco Jose Angel Diosdado-De la Pena Gerardo israel Pdrez-Soto Alonso Salazar-Garibay Juan Francisco Reveles-Arredondo Gilberto Villalobos-Llamas Pedro Duran-Resendiz Department of Mechanical Engineering Universidad de Guanajuato (DICIS) Salamanca M~xico

This paper presents a non-linear simulation of the impact on a structure with different energy absorption systems using finite element models. Literature review on bistable structure, aluminum foam and expandable polystyrene is presented and taken as basis to propose energy absorption systems. Using a base structure, these systems are implemented by means of finite element modeling. A comparison of the damage caused to the structure in case of impact without implementing energy absorption system, and implementing energy absorption systems based on bistable structures, polystyrene foam and aluminum foam are shown here in. The results demonstrate the advantages of using energy absorption systems on structures under impact loads.

关键词： Bistable impact loads non-linear analysis energy absorption.

Water Quality Assessment of a Tropical Mexican Lake Using Multivariate Statistical Techniques

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 Environmental Protection 2015年第3期6卷 215-224页

作者： Jessica Badillo-Camacho Eire Reynaga-Delgado Isela Barcelo-Quintal Pedro F.Zarate del Valle Ulrico J.Lopez-Chuken Eulogio orozco-Guareno Jorge israel AlvarezBobadilla Sergio Gomez-Salazar Departamento de Quimica Universidad de Guadalajara-Centro Universitario de Ciencias Exactas e IngenieriasGuadalajaraMexico Departamento de Farmacobiologia Universidad de Guadalajara-Centro Universitario de Ciencias Exactas e IngenieriasGuadalajaraMexico Departamento de Ciencias Basicas Universidad Autonoma MetropolitanaUnidad AzcapotzalcoMexico D.F.Mexico Facultad de Ciencias Quimicas Universidad Autonoma de Nuevo LeonSan Nicolas de los GarzaMexico Departamento de Ingenieria Quimica Universidad de Guadalajara-Centro Universitario de Ciencias Exactas e IngenieriasGuadalajaraMexico

Water quality of Mexican tropical lake Chapala was assessed through multivariate statistical techniques, cluster analysis (CA) and principal component analysis (PCA) at ten different monitoring sites for ten physicochemical variables and six metals. This study evaluated and interpreted complex water quality data sets and apportioned of pollution sources to get better information about water quality. From descriptive statistics results, the highest concentrations of metals occurred during the dry season, and this trend was explained by the fact that an unusual rainy event occurred during the month of February 2009 and brought metals into the lake by runoffs from nearby mountains. According to international criteria for water consumption by aquatic organisms [USEPA], only Zn concentration values were below these criteria whereas the values of Ni, Pb, Cd and Fe were above the corresponding values set in these criteria (Ni: 52 μg·L-1, Pb: 2.5 μg·L-1, Cd: 0.25 μg·L-1, and Fe: 1000 μg·L-1). The correlations were observed by PCA, which were used to classify the samples by CA, based on the PCA scores. Seven significant cluster groups of sampling locations—(sites 4 and 5), (sites 3 and 9), (site 7), (site 10), (sites 2 and 6), (site 8) and (site 1)— were detected on the basis of similarity of their water quality. The results revealed that the stress exerted on the lake caused by waste sources follows the order: domestic > agricultural > industrial.

关键词： Multivariate Statistical Analysis toxic Metals Water Quality Lake Pollution

Affinity-induced covalent protein-protein ligation via the SpyCatcherSpyTag interaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Green Carbon 2023年第1期1卷 33-42页

作者： Jacob O.Fierer Omar E.Tovar-herrera Jonathan Y.Weinstein Amaranta Kahn Sarah Moraïs Itzhak Mizrahi Edward A.Bayer Department of Biomolecular Sciences the Weizmann Institute of ScienceRehovot 7610001Israel Department of Life Sciences Ben-Gurion University of the NegevBeer Sheva 84105Israel National Institute of Biotechnology in the Negev Ben-Gurion University of the NegevBe’er Sheva 84105Israel The Goldman Sonnenfeldt School of Sustainability and Climate Change Ben-Gurion University of the NegevBeer Sheva 84105Israel

Production of economically viable bioethanol is potentially an environmentally and financially worthwhile *** major source for fermentable sugars is ***,lignocellulosic biomass is difficult to degrade,owing to its inherent structural *** are complexes of cellulases and associated polysaccharide-degrading enzymes bound to a protein scaffold that can efficiently degrade *** of the enzyme subunits into the complex depends on intermodular cohesin-dockerin interactions,which are robust but nonetheless *** modular architecture of these complexes can be used to assemble artificial designer cellulosomes for advanced nanotechnological *** that promote lignocellulose degradation involve high temperatures and acidic or alkaline conditions that could dismember designer cellulosomes,thus requiring separation of reaction steps,thereby increasing overall process *** overcome these challenges,we developed a means of covalently locking cohesin-dockerin interactions by integrating the chemistry of SpyCatcher-SpyTag approach to target and secure the *** resultant cohesin-conjugated dockerin complex was resistant to high temperatures,SDS,and urea while high affinity and specificity of the interacting modular components were *** this approach,a covalently locked,bivalent designer cellulosome complex was produced and demonstrated to be enzymatically active on cellulosic *** combination of affinity systems with SpyCatcher-SpyTag chemistry may prove of general use for improving other types of protein ligation systems and creating unconventional,biologically active,covalently locked,affinity-based molecular architectures.

关键词： Synthetic Biology Protein Ligation Cellulosomes Cohesin Dockerin Protein Engineering Cellulose Degradation