Estudo do comportamento plástico, mecânico, microestrutural e térmico do concreto produzido com resíduo de porcelanato

Population growth experienced in major cities, allied to society s need of infra-structure, especially ones related to habitational demands, increases the consumption of construction materials. As a consequence, consumption of natural resources itself. Thus, due to this process, concrete is one of the most produced materials in civil construction. This is also due to the great diversity of its application, easiness in its execution and adequate mechanical performance, as well as low production costs. Following the same tendencies in construction development, the ceramic industry has intensified the production of porcelain ceramic tiles and floors. These are achieved by a fine finishing and receive polishing at the end of the fabrication process. This work researched the use of porcelain residues in polishing for the production of concrete. All of which; due to economical and environmental issues. This process aims to prove adequate destiny for this type of residue, due to environmental issues, incorporating it to the concrete itself; all of which provides economy in consumption of the materials that constitute concrete. Thus, the main characteristics of concrete were investigated through the inclusion of different concentration of the porcelain residue as additional trait element. The residue rates incorporated to the trait varied from 10% to 50% in relation to the cement mass, in the traits with plastic additives and without plastic additives. It is observed that the inclusion of porcelain residue produced a meaningful alteration in the consistency of fresh concrete. This residue has a fine granulometry and it considerably absorbed the water used in the concrete spreading, influencing the way this material is dealt with. Thus, the value of cement striking decreases with the increase of residues present in trait. The maximal incorporation of the residue was of 50%, massively, for the same factor water/initial cement. The use of residues in concrete results in an 40% increase in the compression resistance. It is also proportional to residue concentration of porcelain in the trait. The microstructure was also favored once porosity and concrete absorption decreases with the use of this residue. The parameters demonstrate the quality and durability of the concrete produced with this residue. The use of porcelain residue in concrete composition has not produced meaningful thermal behavior changes. Thermal conductivity, heat capacity and thermal diffusivity have been maintained basically constant

Crescimento econômico e restrição externa da economia brasileira: uma análise do padrão das exportações em relação ao BRIC e do Sistema de Inovação do Brasil (1980-2012)

This Master s Thesis aims to use the theoretical models of growth with restricted balance of payments, specifically Kaldor (1970) and Thirlwall (1979) models, to analyze the behavior and the pattern of specialization of Brazilian exports and imports in the last years. It is observed that, in some periods, the pattern of specialization has contributed in restricting long-term growth of the Brazilian economy. It has been hypothesized that overall this is due to lack of structural transformation policies. To achieve this goal, it analyzed the performance of Brazilian exports and imports disaggregating them according to their technological content. The basis for comparison was a group of countries to which Brazil is inserted in, the BRIC. In this regard, the work is a comparative analysis by using descriptive statistics. It is concluded that the low rate of GDP growth experienced by Brazil since the 1980s can be explained in part by the decoupling of the Brazilian National Innovation System (NIS) and the Brazilian productive structure. This would be reducing the income elasticity of exports and raising imports, causing a pattern of specialization intensive primary commodities and labor and low-skill labor

Estudo do efeito do óxido de bário no comportamento de massas para porcelanato

In this work, it is proposed the study of the effect of barium oxide acting as synthetic flow in the behavior of masses for stoneware from the use of raw materials found in the deposits of minerals of the Rio Grande do Norte that it makes use of a great natural potential for the industrialization of the product. The porcelanato is a sophisticated product with excellent final properties being applied as ceramic coating in buildings of high standard of engineering. The raw materials selected for the development of the study had been two types of argilas, two types of feldspatos, dolomita, talco, barium carbonate and silica, being characterized by X-ray fluorescence, X-ray diffraction, granulometric analysis, dilatometric analysis and thermal analysis. Thus, it is intended to define four formulations using the cited raw materials that will be processed, conformed and sintered in the temperatures of 1150 °C, 1175 °C, 1200 °C, 1225 °C e 1250 °C. From the physical characterizations, chemical and morphologic of the formed formulations, the effect of barium oxide is determined in the physical and mechanical properties of the studied system carrying water absorption tests, linear retraction, apparent porosity, apparent specific mass, compacting curve, flexural strength and microstructural analysis by XRD and SEM. After analyzing the results, indicated that barium oxide acts as a flux of high temperature and as the ordering of structure, where the embedded glass phase has the nucleating effect phase potassium silico-aluminum reacting with free silica which together with the high content of potassium concentrated form a new crystalline phase called microcline. The masses studied with the addition of barium oxide present physical-mechanical properties highly satisfactory in reduced firing temperatures, which implies a saving in energy given off in the production and increased productivity

Comportamento do camarão de água doce macrobrachium rosenbergii (De Man, 1879) em cultivos misto e monossexo

Understanding the behavioral activities of freshwater shrimp in captivity is of paramount importance for the appropriate management of the species. In Brazil, the shrimp Macrobrachium rosenbergii is currently the most widely used species in the freshwater shrimp culture due to its high potential for cultivation and good market acceptance. Thus, the present study aimed to describe and characterize the behavioral activities of M. rosenbergii in monosex and in mixed (male and female) (manuscript 1, 2 and 3) populations and the growth performance of this species in restrictive feeding conditions and in different feeding management (manuscript 4 and 5, respectively) . Juvenile and adult shrimps were collected from ponds of the Aquaculture Station - Unidade Especializada em Ciências Agrárias - Universidade Federal do Rio Grande do Norte (UFRN), Macaíba/RN and then transferred to the Laboratório de Estudos do Comportamento do Camarão LECC (Laboratory for Shrimp Behavioral Studies) of the Universidade Federal do Rio Grande do Norte (UFRN). For each treatment , eight aquaria of 250 L (50 cm x 50 cm x 100 cm) were used in a closed recirculating water system with artificial lighting, constant aeration , continuous filtration through a biochemical and biological filter (canister filter), and fine sand as substrate . The water quality was monitored daily. The lab consisted of two rooms with artificial lighting system , controlled by a timer with dark / light cycle of 12:12 h . In manuscript 1, the behavioral categories of the species were presented through an ethogram, which described 31 behaviors, subdivided into general and agonistic behaviors. Manuscript 2 compared the behavioral profile of shrimps in male and in female monosex and mixed populations over 24 hours in laboratory. In three types (mixed, male monosex and female monosex) of populations during the light and dark phases of the 24 hour cycle, the shrimps showed higher occurrence of cleaning behavior. Manuscript 3 examined the influence of the color of the shelter on the frequency of its use and behavioral activities of shrimp in mixed, in male monosex and in female monosex populations over 24 hours. We observed that the shrimp M. rosenbergii burrow more frequently during the light phase in male monosex and mixed populations; they also tend to choose the black shelters. Female monosex populations tend to use red and orange shelters. In manuscript 4, we evaluated in laboratory the behavioral activities and growth performance of juvenile shrimps under food restriction. We observed that a mild food restriction may be used since there is no loss concerning the growth of the animals; feeding management on alternate days , compared to daily management can be financially productive both reducing labor costs and reducing the amount of feed used . Manuscript 5 evaluated the behavior of shrimps in monosex and in mixed populations, as well as the latency of reach the food according to feed offer (tray or food dispersal) . Our results indicate that animals adjust to both types of feed offer food dispersal as much as tray, but they spend more time to reach the feed when it is offered in trays (feeders). Comparing culture types (mixed, male monosex and female monosex), the latency to reach the food was lower for female monosex population. The data obtained in this study demonstrate the importance of identifying different pressures and environmental stimuli on the behavioral responses of this species. This knowledge would support management improvement to optimize the levels of animals‟ welfare, resulting in a better zootecnical performance

Estudo do comportamento plástico, mecânico, microestrutural e térmico do concreto produzido com resíduo de porcelanato

Population growth experienced in major cities, allied to society s need of infra-structure, especially ones related to habitational demands, increases the consumption of construction materials. As a consequence, consumption of natural resources itself. Thus, due to this process, concrete is one of the most produced materials in civil construction. This is also due to the great diversity of its application, easiness in its execution and adequate mechanical performance, as well as low production costs. Following the same tendencies in construction development, the ceramic industry has intensified the production of porcelain ceramic tiles and floors. These are achieved by a fine finishing and receive polishing at the end of the fabrication process. This work researched the use of porcelain residues in polishing for the production of concrete. All of which; due to economical and environmental issues. This process aims to prove adequate destiny for this type of residue, due to environmental issues, incorporating it to the concrete itself; all of which provides economy in consumption of the materials that constitute concrete. Thus, the main characteristics of concrete were investigated through the inclusion of different concentration of the porcelain residue as additional trait element. The residue rates incorporated to the trait varied from 10% to 50% in relation to the cement mass, in the traits with plastic additives and without plastic additives. It is observed that the inclusion of porcelain residue produced a meaningful alteration in the consistency of fresh concrete. This residue has a fine granulometry and it considerably absorbed the water used in the concrete spreading, influencing the way this material is dealt with. Thus, the value of cement striking decreases with the increase of residues present in trait. The maximal incorporation of the residue was of 50%, massively, for the same factor water/initial cement. The use of residues in concrete results in an 40% increase in the compression resistance. It is also proportional to residue concentration of porcelain in the trait. The microstructure was also favored once porosity and concrete absorption decreases with the use of this residue. The parameters demonstrate the quality and durability of the concrete produced with this residue. The use of porcelain residue in concrete composition has not produced meaningful thermal behavior changes. Thermal conductivity, heat capacity and thermal diffusivity have been maintained basically constant