4 resultados para Sobolev inner products

em Universidade Federal do Rio Grande do Norte(UFRN)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

OLIVEIRA, E. L. et al. Use of Fibres obtained from the Cashew (Anacardium ocidentale, L) and Guava (Psidium guayava) Fruits for Enrichment of Food Products. Brazilian Archives of Biology and Technology, Curitiba, PR, v. 48, p. 143-150, 2005.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Sisal is a renewable agricultural resource adapted to the hostile climatic and soil conditions particularly encountered in the semi-arid areas of the state of Rio Grande do Norte. Consequently, sisal has played a strategic role in the economy of the region, as one of few options of income available in the semi-arid. Find new options and adding value to products manufactured from sisal are goals that contribute not only to the scientific and technological development of the Northeastern region, but also to the increase of the family income for people that live in the semi-arid areas where sisal is grown. Lignocellulosic fibers are extracted from sisal and commonly used to produce both handcrafted and industrial goods including ropes, mats and carpets. Alternatively, addedvalue products can be made using sisal to produce alumina fibers (Al2O3) by biotemplating, which consists in the reproduction of the natural fiber-like structure of the starting material. The objective of this study was to evaluate the conditions necessary to convert sisal into alumina fibers by biotemplating. Alumina fibers were obtaining after pretreating sisal fibers and infiltrating them with a Al2Cl6 saturated solution, alumina sol from aluminum isopropoxide or aluminum gas. Heat-treating temperatures varied from 1200 ºC to 1650 °C. The resulting fibers were then characterized by X-ray diffraction and scanning electronic microscopy. Fibers obtained by liquid infiltration revealed conversion only of the surface of the fiber into α-Al2O3, which yielded limited resistance to handling. Gas infiltration resulted in stronger fibers with better reproduction of the inner structure of the original fiber. All converted fibers consisted of 100% α-Al2O3 suggesting a wide range of technological applications especially those that require thermal isolation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis approaches the situation of small and medium Brazilian companies facing the exportation process, focusing honey (Apis Mellifera). The world economy has had growing market internationalization, known as globalization. In this context, the exportation has to be faced as a way to minimize the inner market difficulties and increase the levels of quality and productivity to attend the external markets in a competitive way. A company exportation process is not linked to its dimensions, but connected to the commitment with quality, creativity and professionalism. The search for new productive frontiers has benefited Brazilian beekeeper, mainly the northeast ones. Besides, the claim for products that are free of chemical remains, with a bigger aggregate value has increased every day, and the Apismel Company is benefited for having potential to produce organic honey. This paper approaches a case study realized with Sixty-nine beekeeper from Serra do Mel, RN, that make the Apismel Company and it aims to investigate the competitive factors that affects honey exportation. In order to obtain subsidies to execute the objective of this work, it was chosen a questionnaire as instrument of research. The questionnaire was structured from variables that were considered as directions of competition in honey exportation. The results were tabled in Software (Statistics version 11.0). The descriptive, exploiter and Kolmogorov-Smirnov analyses were used to analyze the obtained results. At the end, this work recommends that the Apismel Company promote capacitating courses and technical consultations at the many villages that make the county, to ripen and add efficiency in handling implementation in order to equilibrate production factors and to attract inner and external markets

Relevância:

20.00% 20.00%

Publicador:

Resumo:

It is analyzed through the concepts of tribology and mechanical contact and damage the suggestion of implementing a backup system for traction and passage of Pipeline Inspection Gauge (Pig) from the inside of pipelines. In order to verify the integrity of the pipelines, it is suggested the possibility of displacement of such equipment by pulling wires with steel wires. The physical and mechanical characteristics of this method were verified by accelerated tests in the laboratory in a tribological pair, wire versus a curve 90. It also considered the main mechanisms of wear of a sliding system with and without lubricant, in the absence and presence of contaminants. To try this, It was constructed a test bench able to reproduce a slip system, work on mode back-and-forth ("reciprocation"). It was used two kinds of wires, a galvanized steel and other stainless steel and the results achieved using the two kinds of steel cables were compared. For result comparative means, it was used steel cables with and without coating of Poly Vinyl Chloride (PVC). The wires and the curves of the products were characterized using metallographic analysis, microhardness Vickers tests, X-ray diffraction (XRD), X-Ray Refraction (XRF) and tensile tests. After the experiments were analyzed some parameters that have been measurable, it demonstrates to the impracticality of this proposed method, since the friction force and the concept of alternating request at the contact between the strands of wire and the inner curves that are part ducts caused severe wear. These types of wear are likely to cause possible failures in future products and cause fluid leaks