Modelling the melting and solidification of solder material

Abstract not available

Computational modelling of defects in fibre optic cables

Abstract not available

Multiphysics modelling of solder joint formation

Abstract not available

A Multimedia Video Player Based of FFmpeg

With the rapid development of Internet technologies, video and audio processing are among the most important parts due to the constant requirements of high quality media contents. Along with the improvement of network environment and the hardware equipment, this demand is becoming more and more imperious, people prefer high quality videos and audios as well as the net streaming media resources. FFmpeg is a set of open source program about the A/V decoding. Many commercial players use FFmpeg as their displaying cores. This paper designed a simple and easy-to-use video player based on FFmpeg. The first part is about the basic theories and related knowledge of video displaying, including some concepts like data formats, streaming media data, video coding and decoding. In a word, the realization of the video player depend on the a set of video decoding process. The general idea about the process is to get the video packets from the Internet, to read the related protocols and de-encapsulate the protocols, to de-encapsulate the packaging data and to get encoded formats data, to decode them to pixel data that can be displayed directly through graphics cards. During the coding and decoding process, there could be different degrees of data losing, which is called lossy compression, but it usually does not influence the quality of user experiences. The second part is about the principle of the FFmpeg decoding process, that is one of the key point of the paper. In this project, FFmpeg is used for the main decoding task, by call some main functions and structures from FFmpeg class libraries, packaging video formats could be transfer to pixel data, after getting the pixel data, SDL is used for the displaying process. The third part is about the SDL displaying flow. Similarly, it would invoke some important displaying functions from SDL class libraries to realize the function, though SDL is able to do not only displaying task, but also many other game playing process. After that, a independent video displayer is completed, it is provided with all the key function of a player. The fourth part make a simple users interface for the player based on the MFC program, it enable the player could be used by most people. At last, in consideration of the mobile Internet’s blossom, people nowadays can hardly ever drop their mobile phones, there is a brief introduction about how to transplant the video player to Android platform which is one of the most used mobile systems.

Extração de blocos graníticos nas pedreiras de Cinza Ariz e Amarelo Macieira da empresa Polimagra – Granitos, S.A

A perfuração em maciços rochosos desempenha um papel fundamental na área da exploração e extração de rocha ornamental, nomeadamente em granitos. Para esse efeito, e como irá ser abordado neste trabalho, são utilizados pela empresa Polimagra – Granitos, S.A, nas pedreiras que explora, dois sistemas de perfuração: perfuração hidráulica e perfuração pneumática. Sendo um dos objetivos deste trabalho perceber qual o tipo de perfuração que apresenta maior rentabilidade, torna-se importante perceber as principais características dos dois sistemas de perfuração em estudo. Para isso, com a realização deste estágio curricular na empresa Polimagra – Granitos, S.A, foi possível comparar as principais diferenças dos dois sistemas utilizados, através do acompanhamento dos trabalhos de lavra em pedreiras, da cronometragem de tempos de perfuração em maciço rochoso granítico e da realização de um estudo de fracturação nas pedreiras de Cinza Ariz e Amarelo Macieira. Durante este tempo do estágio foi ainda possível acompanhar os diferentes métodos de transformação utilizado sobre os diferentes granitos obtidos, nas instalações fabris da empresa Polimagra – Granitos, S.A. De destacar ainda, e dentro da área da transformação do granito, a utilização de um sistema robótico de tecnologia de ponta, para corte, acabamento e embalamento de produtos em granito.

Desempenho térmico de coberturas: Um estudo comparativo entre as telhas de material reciclado, de fibra e betume, fibrocimento e cerâmica

This study aims to compare the thermal performance of tiles made from recycled material (waste packaging cardboard with aluminized film) with the tiles of fiber and bitumen, fiber cement and red ceramic with the aim of verifying the suitability of tile to be used in hot and humid climate of low latitude. The samples were selected according to the availability from Natal - RN market, as they are sold to the consumers. The methodology was based on studies that used experimental apparatus composed of thermal chambers heated by banks of incandescent bulbs, to analyze the thermal performance of materials. The tiles in the study were submitted to analysis of thermal performance, thermophysical properties and absorptance, using chambers of thermal performance, measuring the thermophysical properties and portable spectrometer, respectively. Comparative analysis of thermal performance between two samples of the recycled material with dimple sizes and different amounts of aluminum were made, in order to verify, if these characteristics had some interference on the thermal performance of them; the results showed no significant performance differences between the samples. The data obtained in chambers of thermal performance and confirmed by statistical analysis, showed, that the tile of recycled material have similar thermal performance to the tile of fiber cement. In addition to these tests was carried out the automatic monitoring of a building covered with tiles of recycled material, to verify its thermal performance in a real situation. The results showed that recycled shingles must be used with technical criteria similar to those used for fiber cement tiles, with regard to the heat gain into the building. Within these criteria should be taken into account local characteristics, especially in regions with hot and humid climate, and its use must be associated, according to the literature, to elements of thermal insulation and use of passive techniques such as vented attics, ceilings and right foot higher

Melhoria da qualidade de jerked beef pela substituição de nitrito de sódio por extratos naturais de própolis e erva mate como agente antioxidante

Jerked beef, an industrial meat product obtained from beef with the addition of sodium chloride and curing salts and subjected to a maturing and drying process is a typical Brazilian product which has been gradually discovered by the consumer. The replacement of synthetic antioxidants by natural substances with antioxidant potential due to possible side effects discovered by lab tests, consumer health, is being implemented by the meat industry. This study aimed to evaluate the lipid oxidation of jerked beef throughout the storage period by replacing the sodium nitrite by natural extracts of propolis and Yerba Mate. For jerked beef processing brisket was used as raw material processed in 6 different formulations: formulation 1 (control - in nature), formulation 2 (sodium nitrite - NO), formulation 3 (Yerba Mate - EM), formulation 4 (propolis extract - PRO), formulation 5 (sodium nitrite + Yerba Mate - MS + NO), formulation 6 (propolis extract + sodium nitrite - PRO + NO). The raw material was subjected to wet salting, dry salting (tombos), drying at 25°C, packaging and storage in BOD 25°C. Samples of each formulation were taken every 7 days for analysis of lipid oxidation by the TBARS method. In all formulations, were carried out analysis of chemical composition at time zero and sixty days of storage. The water activity analysis and color (L *, a *, b *) was monitored at time zero, thirty and sixty days of storage. The Salmonella spp count, Coliform bacteria, Termotolerant coliforms and coagulase positive staphylococci were taken at time zero and sixty days. The activity of natural antioxidants evaluated shows the decline of lipid oxidation up to 2.5 times compared with the product in natura and presented values with no significant differences between treatments NO and EM, confirming the potential in minimize lipid oxidation of Jerked beef throughout the 60 days of storage. The results also showed that yerba mate has a higher antioxidant capacity compared to the propolis except the PRO + NO formulation. When associated with yerba mate with sodium nitrate, TBARS values become close to values obtained only for the control samples with the addition of sodium nitrite. The proximal composition of the formulations remained within the standards required in the IN nº22/2000 for jerked beef. Samples that differ significantly at 5% are directly related to the established type of formulation. The count of microorganisms was within the standards of the DRC nº12/2001 required for matured meat products. The intensity of the red (a*) decreased with storage time and increase the intensity of yellow (b*) indicates a darkening of the product despite L* also have been increased. These results suggest that yerba mate is a good alternative to meat industry in reducing healing addition salts when associated with another antioxidant.

Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage

The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189 +/- 58 operational taxonomic units (OTUs) but dropped to 27 +/- 12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota.

Caracterização da fração de óleo de café extraido de grãos sadios, verdes e preto-verdes, e a influência na adição deste na sensorial de café liofilizado

The application of roasted coffee oil directly on freeze dried soluble coffee is used to minimize the formation of fine poder which adhere on the glass packaging, which results in a negative visual appearance, as well as contributes to the aromatic impact when opening the packaging. The coffee oil is considered a high cost product obtained from Arabica coffee beans, previosly selected and roasted, by mechanical press. In Brazil the coffee culture and marketing results in the selection of the beans by type of defects and beverage, the volume of exportation works with types of coffee beans with low quantity of defects resulting in a large volume of defective coffee beans trading on the domestic market. Nevertheless, coffees which present defective grains like green, black-green beans present differences in the final flavor of the roasted coffees. The aim of this study was to evaluate the chemical composition of the oils extracted from grains classified as normal, green and black-green, at natural and roasted conditions. The oil was obtained by cold extraction using solvents of different polarities, and yield was calculated as well as its fatty acid composition. The oil of the roasted defective coffee grains was also used to prepare drinks of lyophilized soluble coffee in order to verify if jugdes were able to differenciate the sensory caracteristics of the beverages, in comparison to the product prepared using commercial oil obtained by mechanical pressing. Samples of oil obtained from defective grains showed similar extraction yields compared to hot extraction. Cromatographs of oils of the deffective grains did not showed differences compared to normal grains. In relation to the sensory analysis of the soluble coffee beverages, it was verified that when applying oils of light roasted black-green beans or oils of medium and dark roasted green beans obtained with rapid process, judges had more difficulties to distinguish differences between samples. Economic viability demonstrated that with the actual prices of the coffee beans, the use of defective beans could reduce in 64% the costs of the raw beans.