392 research outputs found
Ti3SiC2-Cf composites by spark plasma sintering: Processing, microstructure and thermo-mechanical properties
MAX phases, and particularly Ti3SiC2, are interesting for high temperature applications. The addition of carbon fibers can be used to reduce the density and to modify the properties of the matrix. This work presents the densification and characterization of Ti3SiC2 based composites with short carbon fibers using a fast and simple fabrication approach: dry mixing and densification by Spark Plasma Sintering. Good densification level was obtained below 1400 °C even with a high amount of fibers. The reaction of the fibers with the matrix is limited thanks to the fast processing time and depends on the amount of fibers in the composite. Bending strength at room temperature, between 437 and 120 MPa, is in the range of conventional CMCs with short fibers and according to the resistance of the matrix and the presence of residual porosity. Thermo-mechanical properties of the composites up to 1500 °C are also presented.This work has received funding from the European Union’s Horizon2020 “Research and innovation programme” under grant agreement No 685594 (C3HARME
The Synthesis and Characterization of Gadolinium Alginate Spheres and Potential Uses as a Contrast-Enhancing Anti-Cancer Material
https://openworks.mdanderson.org/sumexp23/1032/thumbnail.jp
Fabrication of radiopaque, drug loaded resorbable inferior vena cava filters
https://openworks.mdanderson.org/sumexp23/1073/thumbnail.jp
HYDRA: Macroscopic modeling of hybrid ablative thermal protection system
In the framework of HYDRA, an European funded program, technological solutions of hybrid Thermal Protection System (TPS) are developed. This advanced shielding relies on the hybridization of upper lightweight porous ablative material and inner Ceramic Matrix Composite (CMC) bonded together with a novel high temperature adhesive. The aerial mass optimization of the full TPS requires a controlled reduction in the ablative material thickness to reach high operating temperature configuration of the CMC. Therefore, radiative heat transfer takes place in a thin layer of ablator and becomes a major contributor to the elevation of the interface temperature. In this paper we develop an high fidelity radiative transfer in porous carbon fibers charring and ablative material. Specific elementary characterization, plasma test campaign and numerical simulation are scheduled to feed this radiative heat transfer model
Uncertain pasts and risk-sensitive futures in sub-Saharan urban transformation
This chapter explores the status and the scope for transition of risk- sensitive and transformative urban development in diverse cities of sub-Saharan Africa. Sub-Saharan Africa is important because of its large proportions of urban populations with high vulnerability and growing exposure to risks. High rates of urban growth pose increasing risks as we go into the future, yet there is also opportunity to reduce risk through integrating risk management into development. However, this opportunity space is often constrained by limited capacities to plan and manage the rapid urbanisation process, particularly in informal settlements. Limited capacities to prevent processes of risk accumulation pose threats to poverty reduction and sustainable development. In this context, there is an increasingly urgent need for squarely recognising and addressing the underlying vulnerabilities of urban populations and their root causes. Transitioning towards such sustainable urban pathways will require the strengthening of capacities and accountability of city authorities and broader governance systems, both formal and informal
Caracterização do pão regional do distrito de Viseu e de Pão São
Dissertação de Mestrado em Qualidade e Tecnologia AlimentarO objectivo deste estudo visa a caracterização de diferentes amostras de pão Regional e pão São, procurando encontrar semelhanças e identificar os elementos diferenciadores dos mesmos. As amostras de pão Regional foram recolhidas no distrito de Viseu: Carregal do Sal, Cabanas de Viriato, Santar, Viseu, Mangualde, São Pedro do Sul e São Cipriano. No caso do pão São as amostras foram fornecidas pela empresa produtora, Fábrica do Pão localizada em Seia. Procedeu-se à caracterização física, química e sensorial, tendo sido avaliadas as diferentes propriedades em termos de média e desvio padrão das réplicas efectuadas. Posteriormente, procedeu-se a uma análise estatística, para comparação de médias e avaliação da significância das diferenças, tendo para tal sido usado o teste de Tuckey HSD. Foram ainda calculados os coeficientes de correlação de Pearson. Os resultados foram analisados recorrendo ao software SPSS para o Windows versão 19.0 e Statistic versão 6., sendo realizado o teste de análise de variância "one-way" (ANOVA). Numa fase posterior, os valores obtidos para as características do pão foram sujeitos a uma análise de componentes principais (PCA) e uma análise de Cluster. Em relação aos parâmetros químicos analisados no pão Regional, as amostras apresentaram algumas semelhanças e algumas diferenças, assim como também a nível físico e sensorial. No entanto, no que respeita à análise sensorial, as amostras foram, de modo geral, percepcionadas da mesma forma pelos provadores, não sendo detectadas diferenças significativas. Ainda assim, em termos de apreciação global a amostra preferida foi a da pastelaria Flor de Cabanas. Em relação aos parâmetros químicos, físicose sensoriais do pão São, as amostras mostraram-se semelhantes entre si, o que pode ser explicado por terem basicamente a mesma constituição em termos de ingredientes. Contudo, será de assinalar algumas diferenças em termos de fibra, hidratos de carbono, proteína e cloretos, devido à presença de farinha de tremoço numa das amostras. Quando comparadas as amostras de pão Regional com as de pão São, verificou-se que estas se apresentaram bastante diferentes, quer em termos químicos, físicos ou nível sensorial. Foi possível observar que ao nível sensorial os pães Regionais foram os preferidos pelos provadores.ABSTRACT: The aim of this study is the characterization of different samples of regional bread and healthy bread, trying to identify the similarities and contrasting elements in them. The regional bread samples were collected in the District of Viseu: Carregal do Sal, Cabanas de Viriato, Santar, Viseu, São Pedro do Sul and São Cipriano. The healthy bread samples were provided by the production company "Fábrica do Pão", located in Seia. The physical, chemical and sensory characterization was undertaken, having been avaluted the different proprerties in terms of mean value and standard deviation of the replicas made. Later, we proceeded to a statistical analysis for comparison of means and assessing the significance of the differences, having been used for this the Tukey HSD test. We also calculated the Pearson correlation coefficients. The results were analyzaed using the SPSS software version 19.0 for Windows and Statistica version 6, having been performed an analysis of variance "one way"(ANOVA). At a later stage, the values obtained for the characteristics of bread were subjected to principal components analysis (PCA) and cluster analysis. Regardind the chemical parameters analyzed in the regional bread, the samples showed some similarities and differences, as well as regarding the physical and sensory parameters. However, concerning the sensory analysis, the samples were generally perceived by the panelists in the same way, and no significant differences were observed. Still, in terms of the same way preferred by the panelists the sample from pastry "Flor de Cabanas". With respect to chemical, physical and sensory parameters of the healthy bread, the samples were similar, which can be explained by having basically the same constitution in terms of ingredients. However, there can be noted some differences in terms of fiber, carbohydrates, protein and chlorides, due to the presence of lupine flour in one sample. When comparing the regional bread samples with the healthy bread ones, it was found that they quite different, either at the chemical, physical or sensory levels. It was observed that at the sensory level the regional breads were those preferred by the tasters
Evaluation of Clinical and Immunopathological Features of Different Infective Doses of Trypanosoma cruzi in Dogs during the Acute Phase
Infection with Trypanosoma cruzi is a major risk in Latin America, and dogs are believed to be good models for evaluating Chagas disease. Here, we evaluated the clinical and immunopathological alterations developed by mongrel dogs experimentally infected with different infective doses (2,000, 20,000, and 200,000 metacyclic trypomastigotes of Sylvio X10/4 strain kg−1 via intraperitoneal). Clinical and electrocardiographic parameters, as well as antibody production and pathologic lesions were evaluated. All three doses of this strain of T. cruzi induced a similar pattern of infection characterized by cardiac arrhythmias and severe and diffuse myocarditis. Specific anti-T. cruzi IgG indicated seroconversion by day 14 after infection, and IgG levels increased during the period of evaluation. Mortality was observed only in dogs infected with the medium or high parasite doses, but not in the group infected with a low dose of 2,000 parasites kg−1. Infection with a low dose of parasites provides an excellent nonlethal model to evaluate the immunopathology of the acute disease in dogs infected with the Sylvio X10/4 strain of T. cruzi
- …