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Thermal and Mechanical Properties of Thermoplastic Starch and Poly(Vinyl Alcohol-Co-Ethylene)Blends

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Journal of Renewable Materials 2019年第3期7卷 245-252页

作者： Ana Clara Lancarovici Alves Rafael Grande antonio josé felix carvalho Department of Materials Engineering Sao Carlos School of EngineeringUniversity of Sao PauloAv.Joao Dagnone110013563-120Sao Carlos-SP-Brazil

The interest in thermoplastic starch(TPS)as a substitute material to replace conventional thermoplastics continues especially due its biodegradability,availability,low cost and because it is obtained from renewable ***,its poor mechanical properties and its high sensitivity to humidity have limited its use in several ***,the copolymer poly(ethylene-co-vinyl alcohol)(EVOH),with two different ethylene contents,27 and 44 mol%were blended with TPS by extrusion in order to overcome these *** obtained blends were characterized by thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),mechanical tensile testing,Scanning Electron Microscopy(SEM)and moisture absorption *** addition of EVOH copolymer did not significantly changed the thermal stability of TPS,however it increased the tensile strength in 65%when compared to *** morphology of the blends did not showed two distinct phases,an indication of miscibility or partial miscibility of the components.A decrease of moisture absorption was obtained by the addition of EVOH and is more pronounced for the EVOH with 44% of ethylene.

关键词： Thermoplastic starch EVOH polymer blends thermal properties of polymers mechanical properties of polymers

Special Issue on 15th Brazilian Polymer Conference:Biopolymers,Eco-Friendly and Biodegradable Polymers and Other Topics Related to Polymeric Materials Derived from Renewable Materials

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Journal of Renewable Materials 2021年第4期9卷 599-600页

作者： antonio Aprigio da Silva Curvelo antonio josé felix carvalho Daniel Pasquini São Carlos Institute of Chemistry University of São PauloSão Carlos13566-590-SPBrazil São Carlos School of Engineering University of São PauloSão Carlos13563-120-SPBrazil Institute of Chemistry Federal University of UberlândiaUberlândia38400-902MGBrazil

This issue of Journal of Renewable Materials is a special issue dedicated to the 15th Brazilian Polymer Conference(15th CBPol)which was held in Bento Gonçalves,Rio Grande do Sul State,Brazil,from 27 to 31 October,2019[1].CBPol is the main scientific forum in the field of polymer science and technology in *** conference has been held biannually since 1991 and in this event had almost 900 participants mainly from Brazil,but also from Argentina,Chile,Peru,USA,Canada,Belgium,France,Great Britain,Portugal and Spain,with 60%students and 40%professionals.A total of 1,100 papers from 2725 authors were presented,from which 25%(280 papers)was in the field of Biomaterials showing the importance of these materials which are in general based on renewable *** 280 works were developed mainly by researchers from Brazilian institutions(universities and research institutes),mainly from the south and southeast regions of the *** subject of more than 70%of the works was dedicated on vegetal raw materials,medicinal applications,packaging and composite materials.

关键词： materials showing annually

Starch Orodispersible Film Loaded with Melatonin for Human Supplementation

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Journal of Renewable Materials 2024年第7期12卷 1343-1354页

作者： Fabio Tamanini Tatiane Zucchini de Souza Creusa Sayuri Tahara Amaral Antônio joséfelix carvalho Eliane Trovatti Department of Health and Biological Sciences University of Araraquara(UNIARA)São Paulo14801-340Brazil Department of Materials Engineering São Carlos School of EngineeringUniversity of São PauloSão Paulo13563-120Brazil

An innovative pharmaceutical form for administering melatonin,based on starch orodispersibleﬁlm(ODF),was designed and *** composition of the ODF included starch as the polymer matrix,the active drug melatonin,and a ***,a natural hormone produced by the pineal gland in the brain,can be absorbed by passive diffusion across the mucous membrane,resulting in improved bioavailability when compared to conventional oral *** study shows a simple and efﬁcient method for preparing melatonin-loaded orodispersibleﬁlms with a physically stable and commercially viable matrix,suitable for use in the pharmaceutical ***ﬁlms were prepared by treating the starch with microwave irradiation,followed by plasticization with glycerol,melatonin loading and drying by solvent *** tests showed theﬁlms’robustness,with a modulus of approximately 97 MPa,indicating good handling *** uptake analysis showed fast water absorption,reaching about 150%within 2 min,indicating its fast oral disintegration *** tests in artiﬁcial saliva and dissolution studies indicated the release of the drug in min-utes,indicating the potential properties of theﬁlm for oral drug *** the best of our knowledge,there is no melatonin ODF based on starch described in the literature.

关键词： Starch orodispersibleﬁlm melatonin drug delivery

Water-Based Processing of Fiberboard of Acrylic Resin Composites Reinforced With Cellulose Wood Pulp and Cellulose Nanofibrils

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Journal of Renewable Materials 2019年第5期7卷 403-413页

作者： Emanoele Maria Santos Chiromito Eliane Trovatti antonio jose felix carvalho Department of Materials Engineering São Carlos School of EngineeringUniversity of São PauloAv.João Dagnone110013563-120São Carlos-SP-Brazil University of Araraquara-UNIARA R.Carlos Gomes1217CEP 14801-320AraraquaraSPBrazil

Despite the great potential of cellulose wood pulp and cellulose nanofibrils as reinforcing filler in thermoplastics,its use is limited due to its tendency to form agglomerates and due to its high hydrophilic *** we describe fiberboard composites with high contents of wood pulp or cellulose nanofibrils,and a resin of poly(styrene-methyl-methacrylate-acrylic acid)used as water-based *** wood pulp and cellulose nanofibrils were used directly in the form of water *** method is based on the flocculation of the polymer emulsion followed by agglomeration of a mixture of the polymer emulsion and cellulose suspension,leading to the co-precipitation of the composite material,which can be easily separated from the water *** with acrylic polymer/cellulose fibers in the proportions of 75:25,50:50 and 25:75 wt%were *** were characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),thermogravimetric analysis(TGA),dynamic mechanical analysis(DMA)and water absorption *** analysis revealed a very good dispersion of the fibers without evidence of agglomeration,which led to superior mechanical *** results showed the effectiveness of the methodology and the potential of cellulose wood pulp and CNF as reinforcement fillers in fiberboard composites and any other high fiber-content materials.

关键词： Cellulose wood pulp cellulose nanofibrils composites acrylic resin emulsion fiberboard

Thermal and salinity effects on locomotor performance of Thoropa taophora tadpoles(Anura,Cycloramphidae)

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Integrative Zoology 2020年第1期15卷 40-54页

作者： antonio C.GALLO Cinthia ABRASILEIRO Fábio Cury DE BARROS joséEduardo DE carvalho Department of Ecology and Evolutionary Biology Federal University of São PauloDiademaSão PauloBrazil

It is well known that environmental temperature influences several biological functions of ectotherms,notably in *** high permeability of anuran skin,associated with the effect of elevated environmental temperature,potentiates the dehydration process and this combination may restrict locomotor ***pa taophora is an endemic species from the Atlantic Rainforest whose tadpoles are semiterrestrial and predominantly diurnal,and are found in rocky seashores where they are exposed to sea spray and high *** this study we investigated how temperature and salinity conditions affect the locomotor performance in Thoropa taophora *** also assessed how different osmotic concentrations affect the activity of the metabolic pathways that support muscle *** measured the sprint speed of tadpoles of various sizes at different temperatures and salinities in the *** also measured the activity of the enzymes pyruvate kinase(PK),lactate dehydrogenase(LDH)and citrate synthase(CS)in different temperatures and osmotic concentrations,and calculated the thermal sensitivity and the activity constants for each *** results showed that,in general,sprint speed decreased with increasing temperature and ***,whereas the effect of increased salinity was similar in smaller and larger tadpoles,increased temperature had a higher negative impact on sprint speed of larger tadpoles,thus indicating low thermal sensitivity of small *** and LDH thermal sensitivities and LDH constant of activity decreased as the osmolality *** conclusion,the locomotor capacity of tadpoles was decreased by temperature and salinity,which may be related to a decrease in anaerobic metabolism both in terms of sensitivity and total energy turnover through enzymatic *** discuss the ecological consequences,including the potential impacts on predator escape behavior promoted by changes in metabolism and locomotor performance

关键词： amphibians energy metabolism enzyme activity sprint speed

ARHCS (Automatic Rainfall Half-Life Cluster System): A Landslides Early Warning System (LEWS) Using Cluster Analysis and Automatic Threshold Definition

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International Journal of Geosciences 2024年第1期15卷 54-69页

作者： Cassiano antonio Bortolozo Luana Albertani Pampuch Marcio Roberto Magalhães De Andrade Daniel Metodiev Adenilson Roberto carvalho Tatiana Sussel Gonçalves Mendes Tristan Pryer Harideva Marturano Egas Rodolfo Moreda Mendes Isadora Araújo Sousa Jenny Power Cemaden - National Center for Monitoring and Early Warning of Natural Disasters General Coordination of Research and Development S&#227o José dos Campos Brazil Environmental Engineering Department Institute of Science and Technology S&#227o Paulo State University S&#227o José dos Campos Brazil Department of Mathematical Sciences University of Bath Bath UK Institute for Mathematical Innovation University of Bath Bath UK

A significant portion of Landslide Early Warning Systems (LEWS) relies on the definition of operational thresholds and the monitoring of cumulative rainfall for alert issuance. These thresholds can be obtained in various ways, but most often they are based on previous landslide data. This approach introduces several limitations. For instance, there is a requirement for the location to have been previously monitored in some way to have this type of information recorded. Another significant limitation is the need for information regarding the location and timing of incidents. Despite the current ease of obtaining location information (GPS, drone images, etc.), the timing of the event remains challenging to ascertain for a considerable portion of landslide data. Concerning rainfall monitoring, there are multiple ways to consider it, for instance, examining accumulations over various intervals (1 h, 6 h, 24 h, 72 h), as well as in the calculation of effective rainfall, which represents the precipitation that actually infiltrates the soil. However, in the vast majority of cases, both the thresholds and the rain monitoring approach are defined manually and subjectively, relying on the operators’ experience. This makes the process labor-intensive and time-consuming, hindering the establishment of a truly standardized and rapidly scalable methodology on a large scale. In this work, we propose a Landslides Early Warning System (LEWS) based on the concept of rainfall half-life and the determination of thresholds using Cluster Analysis and data inversion. The system is designed to be applied in extensive monitoring networks, such as the one utilized by Cemaden, Brazil’s National Center for Monitoring and Early Warning of Natural Disasters.

关键词： Landslides Early Warning System (LEWS) Cluster Analysis Landslides Brazil

应用增爬群改善大雨条件下800 kV叠锥型支柱绝缘子的雨闪性能(英文)

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高电压技术 2011年第11期37卷 2772-2779页

作者： Orsino Oliveira Filho josé antonio Cardoso Darcy Ramalho de Mello Rogério Magalhes de Azevedo Sylvia G carvalho Cepel-Electric Energy Research Center Zip Code 21941-911 Rio de JaneiroRJBrazil Eletrobras Furnas-Centrais Eletricas S/A Zip Code 22283-900 Rio de Janeiro RJBrazil

Studies based on AC high voltage tests have been done at Cepel to investigate the performance of 800 kV busbar insulators under heavy wetting *** were tested which are now used on site and also with different configurations of booster *** recorded by ultra-violet(UV) camera were used to help the investigations on the effectiveness of booster *** comparing UV images of the insulator being stressed with high voltage under heavy artificial rain,with and without booster sheds,it was possible to observe how significant the reduction on the flashover formation process was when booster sheds were *** effectiveness of booster sheds was also quantified by determining the disruptive discharge of the insulator with and without *** results of these studies can also be considered as contribution to national and international standard technical committees to improving the standardized procedure for tests on ultra high voltage(UHV) insulators under heavy *** such as the clear definition of relevant UHV test procedure and test arrangements,including the use of UV camera,have to be taken into account.

关键词： UHV insulator heavy rain booster sheds wet tests disruptive discharge ultra-violet images

Thiopurine-methyltransferase variants in inflammatory bowel disease:Prevalence and toxicity in Brazilian patients

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World Journal of Gastroenterology 2014年第12期20卷 3327-3334页

作者： Ana Teresa P carvalho Barbara C Esberard Renata S B Fróes Davy C M Rapozo Ana B Grinman Tatiana A Simo Juliana C V C Santos antonio josé V Carneiro Luis Felipe Ribeiro-Pinto Heitor S P de Souza Disciplina de Gastroenterologia e Endoscopia Digestiva Universidade do Estado do Rio de Janeiro Programa de Carcinogênese Molecular Instituto Nacional de Cancer Laboratório de Toxicologia e Biologia Molecular Universidade do Estado do Rio de Janeiro Servi?o de Gastroenterologia Departamento de Clínica MédicaUniversidade Federal do Rio de Janeiro

AIM: To analyze the prevalence of thiopurine-methyltransferase (TPMT) genotypes and their association with drug toxicity in inflammatory bowel disease (IBD) patients from southeastern Brazil.

关键词： Inflammatory bowel disease Thiopurine-methyl-transferase Azathioprine Drug toxicity Pancreatitis

Novel LDPE/EVA Nanocomposites with Silver/Titanium Dioxide Particles for Biomedical Applications

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材料科学与工程（中英文B版） 2011年第4期1卷 516-522页

作者： Gabriel Molina de Olyveira Ligia Maria Manzine Costa Ant6nio joss felix de carvalho Pierre Basmaji Luiz antonio Pessan Department of Materials Engineering-Polymers Federal University of S6o Carlos-UFSCar 13565-905 S6o Carlos SP Brazil Department of Materials Engineering S6o Paulo University 13566-590 S6o Carlos SP Brazil Innovatec ＇s-Biotechnology Research and Development Sao Carlos SP Brazil

Nanocomposites with antimicrobial activity are of great interest nowadays and the development of titanium dioxide with these functional properties presents interest in academic and industrial sectors. An approach to develop PE nanocomposite containing Ag nanoparticles to have an antimicrobial effect is presented. To obtain such antimicrobial nanocomposites, LDPE/EVA were processed with Ag nanoparticles on TiO2 particles as inorganic carrier substance. Titanium dioxide nanoparticles (P-25) were covered with silver nanoparticles using Turkevich Method or citrate reduction method. The Ag/TiO2 nanoparticles were dispersed at concentration of 0.5 wt%, 0.8 wt% and 1 wt% in LDPE/ethylene vinyl acetate copolymer (EVA)-(50% w/w) at the melt state in a Haake torque Rheometer. Silver nanoparticles were characterized with UV-Vis Spectroscopy. The nanocomposites thus prepared were characterized through Ares Rheometer, Scanning Electronic Microscopy (SEM) and JIS Z 2801 antimicrobial tests to study the effects of the addition of nanoparticles on rheological properties, morphological behavior and antimicrobial properties. The results showed that incorporation of silver/titanium dioxide nanoparticles on nanocomposites obtained systems with different dispersions. The Ag/TiO2 particles showed uniform distribution of Ag on TiO2 particles as observed by SEM-EDX and antimicrobial tests according to JIS Z 2801 shows excellent antimicrobial properties.

关键词：纳米复合材料二氧化钛颗粒 LDPE 生物医学应用 EVA 含银二氧化钛纳米粒子聚乙烯复合材料