958 resultados para Brasil. Departamento de Polícia Federal
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The multivariate t models are symmetric and with heavier tail than the normal distribution, important feature in financial data. In this theses is presented the Bayesian estimation of a dynamic factor model, where the factors follow a multivariate autoregressive model, using multivariate t distribution. Since the multivariate t distribution is complex, it was represented in this work as a mix between a multivariate normal distribution and a square root of a chi-square distribution. This method allowed to define the posteriors. The inference on the parameters was made taking a sample of the posterior distribution, through the Gibbs Sampler. The convergence was verified through graphical analysis and the convergence tests Geweke (1992) and Raftery & Lewis (1992a). The method was applied in simulated data and in the indexes of the major stock exchanges in the world.
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In soil surveys, several sampling systems can be used to define the most representative sites for sample collection and description of soil profiles. In recent years, the conditioned Latin hypercube sampling system has gained prominence for soil surveys. In Brazil, most of the soil maps are at small scales and in paper format, which hinders their refinement. The objectives of this work include: (i) to compare two sampling systems by conditioned Latin hypercube to map soil classes and soil properties; (II) to retrieve information from a detailed scale soil map of a pilot watershed for its refinement, comparing two data mining tools, and validation of the new soil map; and (III) to create and validate a soil map of a much larger and similar area from the extrapolation of information extracted from the existing soil map. Two sampling systems were created by conditioned Latin hypercube and by the cost-constrained conditioned Latin hypercube. At each prospection place, soil classification and measurement of the A horizon thickness were performed. Maps were generated and validated for each sampling system, comparing the efficiency of these methods. The conditioned Latin hypercube captured greater variability of soils and properties than the cost-constrained conditioned Latin hypercube, despite the former provided greater difficulty in field work. The conditioned Latin hypercube can capture greater soil variability and the cost-constrained conditioned Latin hypercube presents great potential for use in soil surveys, especially in areas of difficult access. From an existing detailed scale soil map of a pilot watershed, topographical information for each soil class was extracted from a Digital Elevation Model and its derivatives, by two data mining tools. Maps were generated using each tool. The more accurate of these tools was used for extrapolation of soil information for a much larger and similar area and the generated map was validated. It was possible to retrieve the existing soil map information and apply it on a larger area containing similar soil forming factors, at much low financial cost. The KnowledgeMiner tool for data mining, and ArcSIE, used to create the soil map, presented better results and enabled the use of existing soil map to extract soil information and its application in similar larger areas at reduced costs, which is especially important in development countries with limited financial resources for such activities, such as Brazil.
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This work was designed to evaluate the effect of storage forms and conditions upon the enzyme activity of phytase and bioavaibility of calcium and phosphorus in broiler diets. The work was accomplished in two steps. The first step, made in the laboratory measured the activity of the phytase enzyme along the storage period. In this step, two experiments were performed: Experiment 1, constituted of 5 treatments (pure phytase stored at 0 °C, 4 °C and environmental temperature and mixed to vitamin and mineral supplement, stored at environmental temperature) in CRD and split plot scheme. The activities were evaluated every 14 days for 112 days of storage, being verified that the phytase storage in the pure form at 0o C was superior to the other treatments. Experiment 2, made up of 4 treatments (phytase mixed to the ration directly, directly and afterwards pelleted, via mineral supplement and via vitamin supplement),all the treatments being stored at environmental temperature, in CRD and split plot scheme. The activities were evaluated every 7 days for 56 days' storage, being verified that the storage of the phytase mixed to the ration via vitamin supplement and directly with the ration pelleted later, provoked a fall in phytase activity when compared with the other treatments. In the second step, the effect of phytase on the bioavaibility of calcium and phytic phosphorus was evaluated, 2 experiments being accomplished (3 and 4); in both experiments were utilized 576 broiler line chicks, housed in an array of heated batteries, receiving practical diets on the basis of corn and soybean meal (basal) for 21days. At the end of 27 days of age,96 birds were slaughtered for evaluation of the mineral contents (Ca and P) in the tíbias and plasma phosphorus. The excretae were collected from 22 to 27 days of age of the birds. Experiment 3: A CRD with the treatments in 2 x 3 x 2 +4 factorial arrangement was utilized, namely, two levels of total phosphorus (0.35 and 0.45% of total phosphorus), three leveis of phytase (500, 750 and 1,000 FTU) and four additional treatments with levels of 0.35 and 0.45 % of available phosphorus for each sex, with three replicates per treatment. There was significant interaction among levels of phosphorus and phytase (P< 0.05) for weight gain, ration consumption and feed conversion. Phytase did not indicate significant differences when the level 0.45% was utilized, nevertheless, at the level 0.35% as phytase was supplemented, weight gain, ration consumption and feed conversion were improved, chiefly with 1,000 FTU/Kg, in both sexes. The males presented greater weight gain. The ration consumption and feed conversion were equal to those of females. The contrast 0.45% did not affect the performance of males and females, the same not occurring with the level 0.35%,at which the available phosphorus was superior in both the sexes. The highest contents of ashes, phosphorus and calcium in the tíbias and plasma phosphorus were obtained with the levels of 750 and 1,000 FTU/Kg of phytase and 0.45% of total phosphorus. The males presented higher contents of ashes in the tibias. The level 0.45% of available phosphorus presented the greatest contents of ashes, calcium and phosphorus in the tibias, and phosphorus in the plasma. The lowest excretions of phosphorus occurred at the levels 0.35% of total phosphorus and 1,000FTU/kg of phytase. The lowest contents of ashes and calcium in the excretae were obtained with 0.35% and 1,000FTU/Kg of phytase. The females excreted smallest amounts of ashes, calcium and phosphorus than the males. Experiment 4: a CRD with the treatments in 3 x 4 x 2 factorial arrangement, namely, three levels of phytase (0, 500 and 1,000 FTU), four levels of calcium (0.7, 0.8, 0.9 and 1.0%) with four replicates per treatment. The performance was not affected by the treatments utilized, the males being superior to the females in weight gain, feed consumption and conversion. The contents of ashes in the tibias were not affected by the levels of phytase but as calcium levels raised, the ash contents increased. The contents of calcium and phosphorus in the tibias increased with the supplementation of 500 and 1,000 FTU/kg of phytase and with calcium levels. The utilization of phytase did not decrease the excretion of ashes, calcium and phosphorus.
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Considering the relevance of researches concerning credit risk, model diversity and the existent indicators, this thesis aimed at verifying if the Fleuriet Model contributes in discriminating Brazilian open capital companies in the analysis of credit concession. We specifically intended to i) identify the economic-financial indicators used in credit risk models; ii) identify which economic-financial indicators best discriminate companies in the analysis of credit concession; iii) assess which techniques used (discriminant analysis, logistic regression and neural networks) present the best accuracy to predict company bankruptcy. To do this, the theoretical background approached the concepts of financial analysis, which introduced themes relative to the company evaluation process; considerations on credit, risk and analysis; Fleuriet Model and its indicators, and, finally, presented the techniques for credit analysis based on discriminant analysis, logistic regression and artificial neural networks. Methodologically, the research was defined as quantitative, regarding its nature, and explanatory, regarding its type. It was developed using data derived from bibliographic and document analysis. The financial demonstrations were collected by means of the Economática ® and the BM$FBOVESPA website. The sample was comprised of 121 companies, being those 70 solvents and 51 insolvents from various sectors. In the analyses, we used 22 indicators of the Traditional Model and 13 of the Fleuriet Model, totalizing 35 indicators. The economic-financial indicators which were a part of, at least, one of the three final models were: X1 (Working Capital over Assets), X3 (NCG over Assets), X4 (NCG over Net Revenue), X8 (Type of Financial Structure), X9 (Net Thermometer), X16 (Net Equity divided by the total demandable), X17 (Asset Turnover), X20 (Net Equity Profitability), X25 (Net Margin), X28 (Debt Composition) and X31 (Net Equity over Asset). The final models presented setting values of: 90.9% (discriminant analysis); 90.9% (logistic regression) and 97.8% (neural networks). The modeling in neural networks presented higher accuracy, which was confirmed by the ROC curve. In conclusion, the indicators of the Fleuriet Model presented relevant results for the research of credit risk, especially if modeled by neural networks.
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The objective of this work was to identify a possible relation between corporate governance, through the structure of the boards of directors and the levels of earnings management of Brazilian public companies. The study is characterized as a descriptive, of a hypothetical-deductive nature, with quantitative approach guided by the estimation model proposed by Kang and Sivaramakrishnan (1995). The sample was comprised by 56 companies, analyzed in the period from 2011 to 2014. The information on the companies were extracted from Economatica databank. For the data analysis, we used multivariate techniques, such as Pearson correlation and panel data in POLS, Fixed Effects and Random Effects approaches. Furthermore, we applied the mean comparison test ANOVA. The results obtained show that, generally, the organizations tend to follow the profile of boards of directors recommended by the codes of corporative governance. However, the characteristics of the composition of the board, regarding its size and the duality of positions that are not yet sufficient to be considered capable of inhibiting the discretionary practice of the studied companies. Relative the control variables, only size and return on equity presented no significant relation with result management. It is important to highlight that literature point many factors that explain the different impacts caused by the formation of the administration board in different regions or countries. Among the factors pointed, we highlight the legal system of the country, the economic and political development, the importance of the capital market, and the level of accounting education.
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In the present study aimed to characterize and quantify four contaminants (ethyl carbamate, 2,3-butanedione, furfural and 5-hydroxymethylfurfural) present in alembic cachaça and industrial. Were collected forty-four samples of cachaça in the southern regions, the Midwest, southeast of Minas Gerais and São Paulo state, and subsequently subjected to physical, chemical and chromatographic analyzes. The physicochemical analyzes were performed according to the methodology described by the Ministry of Agriculture, Livestock and Supply (MAPA). The ethyl carbamate, 2,3-butanedione, furfuaral and 5 hydroxymethylfurfural were characterized and quantified by high-performance liquid chromatography (HPLC). The results of the ethyl carbamate analysis, it was found that both samples showed column cachaças outside the standards required by law, with the values 245.31 235.53 L-1 ug and none of the liquor samples alembic showed concentration greater than 210.0 ug L-1 , and the method is very sensitive to low limits of detection and quantification. In determining 2,3-butanedione, it was revealed that the column cachaças showed higher levels of contaminants when compared to cachaça alembic. In the quantification of furfural and 5-hydroxymethylfurfural was developed and validated analytical methods employed to high-performance liquid chromatography (HPLC) with DAD detector. Samples column cachaças showed higher values than the limit established by Brazilian legislation and ranged from 7.00 to 5.63 mg / 100 ml of anhydrous alcohol over the alembic cachaça.
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Elicitation with chitosan is a tool used to improve the responses of plant defense by inducing secondary metabolism routs. In addition, the adequate application of this elicitor on medicinal plants can promote the increase of major components in the composition of the oil. However, we lack information concerning which are the main physiological processes responsible for the changes in the composition of the oil. Thus, we aimed at evaluating the action of chitosan and determine an ideal concentration for optimizing the production of essential oil in Achillea millefolium L. and the changes in the physiological processes responsible for this increase. The research was conducted in greenhouse of the Plant Physiology sector of the Universidade Federal de Lavras (UFLA) with A. millefolium plants. The treatments consisted of control (water); acetic acid solvent (with no elicitor); and chitosan in the concentrations of 2, 4 and 6 g L -1 . The measurements of growth, gas exchange, enzyme activity of the antioxidant system and phenylalanine ammonia lyase (PAL), in addition to the production and composition of the essential oil. We verified that the application of chitosan promoted decrease in plant growth. However, the concentration of 4 g L -1 of chitosan induced an increase in the content and yield of the essential oil. In the oil, there was predominance of sesquiterpenic compounds, including the major compounds borneol, β-caryophyllene, β-cubebene, α-farnesene and chamazulene. The elicitation with chitosan at 4 g L -1 promoted an increase of the photosynthetic rate, activity of the antioxidant system and of PAL, however, this increase occurred in short-term, only in the first days after elicitation.
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In order to improve the quality and safety of food, the active packaging emerges as a new technology based on the release of composites beneficial to food products. Thus, biodegradable films incorporated with active substances have the function of acting as a barrier to external elements, protecting the product and increasing its shelf life. They are formulated from proteins, polysaccharides, lipids or from the combination of these compounds. However, there is a need to improve the performance properties of these packages. Nanotechnologies, then, emerges with the study of many nanoparticles as additives to modify the performance of biodegradable polymers. With this, we aimed at developing and active antioxidant film of corn starch blenders and whey protein isolate with rosemary essential oil or microcapsules of rosemary essential oil reinforced with sodium montmorillonite (MMTNa + ) nanoparticles by extrusion. The films were developed and characterized in a first stage for the selection of the best polymeric blender using the following analyses: water vapor permeability (WVP), machanical properties; optical, thermogravimetry (TG), differential scanning calorimetry (DSC), x-ray diffraction (XRD) and scanning electron microscopy (SEM). In the second stage, montmorillonite clay nanoparticles and rosemary essential oil were added as reinforcement to evaluate its antioxidant effect. In a third stage, we studied the addition of microcapsules of rosemary essential oil (MR) as a form of protecting the active agent and its antioxidant potential in the films. The results indicate that the development of p olymeric blender with 30% of corn starch substitution is the most indicated for future work. The addition of rosemary essential oil or microcapsule of rosemary essential oil allowed for the obtaining of nanocomposites with antioxidant potential for application in food packages.
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Nature Protection Areas (NPA) are important in the modern world, although still created with no well-defined criteria, overall in state and municipal spheres. In addition, there are no consistent information on the existence or factors that influence the creation and distribution of these areas. The present work had the objectives of identifying the Nature Protection Areas in Minas Gerais, Brazil, considering the municipalities and their mesoregions; perform a space-temporal analysis of the NPAs in Minas Gerais; relate the existence of NPAs with the Municipal Human Development Index (MHDI) and the municipal Gini Index (GI); relate the existence of NPA with the space-temporal and population density of each municipality; relate the Gross Domestic Product (GDP) with the presence of NPAs; relate the existence of NPAs with the occurrence of preservation areas in municipalities within the Atlantic Forest Biome; and verify the influence of the Ecological Sales and Services Tax (Ecological ICMS) institute over the creation of municipal NPAs in Minas Gerais. To reach these objectives, we researched databases, governmental websites, contacted managers and sent questionnaires to the 853 municipalities of Minas Gerais. After tabulating the data, statistical tests were applied to verify possible correlations. The results showed that the state has 9.26% of its territory protected, with the predominance of units of Sustainable Use, especially Environmental Protection Areas, which constitute 69.9% of this area. Only 1.96% of the territory are protected by Integral Protection (IP). We found no correlation between MHDI and the presence of NPAs. However, we verified that municipalities with IP units present higher GI when compared to the others, suggesting that the presence of this conservation unit (CU) model may be associated to social inequality. The results also showed a higher concentration CU in regions that use little of its natural resources as main economic basis and in municipalities with higher GDP. We also registered a positive correlation between the size of the municipalities, of the mesoregions, preserved area of the Atlantic Forest and population density. The Ecological ICMS did not contribute for a better IP in the state and, currently, does not represent an incentive to the creation of CU in Minas Gerais, even in the case of Environmental Protection Areas. This work registered a high degree of vulnerability if the protection system in this state, based on low restriction conservation units.
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Seeking alternatives for the total or partial substitution of synthetic fibers for natural fibers, with reinforcement in polymeric materials, this work was conducted with the objective of evaluating the treatment with corona discharge on the adherence of juta fibers with resin. The fibers were exposed to corona discharge for 1, 5, 10 and 15 minutes, as well as after treatment with hot water, molding composites fiber-reinforced with filaments treated for 10 and 15 minutes, and without the treatment. The chemical structures were evaluated by spectrometry in the region of Fourier transform infrared with attenuated total reflection (FTIR/ATR), observing the formation of a new band and the increase in the absorption of groupings with oxygen. The thermal analyses, such as thermogravimetry (TG) and differential scanning calorimetry (DSC) revealed the degradation of cellulose, hemicellulose and lignin. The microstructural characterization by scanning electron microscopy (SEM) showed changes in the surface of the fiber, such as roughness, superficial depressions, surface degradation and cavity formation. The adhesion of the fibers was evaluated by the pullout test, allowing us to verify the increase in adhesion strength after treatment with corona discharge. In conclusion, the treatment with corona discharge changes the surface of the juta fibers, resulting in better adherence with the resin.
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The tree leguminous gliricídia (Gliricidia sepium), acácia (Acacia mangium), leucena (Leucaena leucocephala) and sombreiro (Clitoria fairchildiana) are indicated for agroforestry systems, reclamation of degraded lands, reforestation and other purposes in the wet tropic. Despite the importance of legumes the preamazon region it is lacking in information about the symbiotic capacity and diversity of indigenous rhizobia of these legumes. The aim of this work was to evaluate the phenotypic and genetic diversity of rhizobia species nodulating gliricidia sombreiro, leucena and acacia in the Maranhão pre-Amazon region and authenticate isolates of these species in siratro (Macroptilium atropurpureum). For this they were installed two experiments. Sampling was carried out on a alley cropping system, was sampled 20 plants of each species by collecting 10 nodules per plant. It was made isolation, cultural characterization, partial 16S rRNA gene sequencing and analysis of the symbiotic ability of bacterial strains with siratro. The authentication experiment was done in two steps for each legume (gliricidia, acácia, sombreiro and leucena), in the greenhouse and in a completely randomized design with three replications with sterile Hoagland nutrient solution as substrate. Gliricídia, Sombreiro, leucena and acacia are colonized by distinct groups of rhizobia. Gliricidia nodulate preferably with Rhizobium, sombreiro and acacia nodulate preferably with Bradyrhizobium and leucena has Mesorhizobium main symbiote. Endophytic strains of ten genera were found colonizing the gliricidia, sombrero, leucena and acacia nodules and a strain of Arthrobacter sp. had a positive nodulation with siratro. This is the first report on isolation of Methylobacterium sp. in gliricidia nodules and endophytic ability of Terriglobus sp. strains. Indigenous strains of pre-Amazon region of Bradyrhizobium, Mesorhizobium and Rhizobium genus nodulate with siratro, but are ineficiente or had low efficiency to promote their growth.
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In this work, magnetic photocatalysts were synthesized containing differents levels of TiO2 (40, 60 e 80%) supported at the supporter of C/LV, forming the photocatalysts 40, 60, 80Ti/C/LV, using tar pitch as carbon (C) source and red mud (LV) as iron source. The prepared magnetic photocatalysts and TiO2 were used to degrade the Remazol Black textile dye (PR5) and the organic material present in samples of a textile dye effluent. The characterization of photocatalysts by Raman, X-Ray Diffraction, Transmission Electron Micoscope and Scanning, Energy Dispersive X-ray Spectrometry, Termogravimetry and Elemental Analysis, confirms the presence of carbon and magnetite in support C/LV and the presence of TiO2 in prepared photocatalysts. The photocatalytic reactions with TiO2 were analyzed by different experimental conditions, such as: mass of TiO2 (30-240 mg), solution pH (2-10), light intensity (0.871 and 1.20 mWcm-2), type of radiation (UV and sunlight-1.420 mWcm-2), radiation incidence area (44.2 to 143.1 cm2) and dissolved oxygen (OD, 1.9 and 7.6 mg L- 1). Results showed that reactions with the following conditions: 220 mg of TiO2, pH 10, solar radiation, 7.6 mg L-1 of OD and an incidence area of radiation of 143.1 cm2 showed the best results for degradation of PR5 dye. Photocatalytic reactions with magnetic photocatalysts for degrading PR5 shows that efficiency increases with TiO2 content in the C/LV support, where, above 60% of TiO2, there was not significant increase in reaction velocity. In addition, solar radiation has proved to be advantageous for photocatalytic reactions. In order to verify the presence of a non-magnetic fraction in the photocatalyst 60Ti/C/LV0, magnetic separation was proceeded. The characterizations of the magnetic (FM) and nonmagnetic (NMF) fraction confirmed that about 25% of TiO2 did not fixed in 60Ti/C/LV photocatalyst. Results of photocatalytic reactions with FM and FNM showed that both phases have photocatalytic activity for degradation of PR5. The reactions executed for the degradation of organic matter present in the actual sample of textile effluent showed that TiO2 and magnetic photocatalyst 60Ti/C/ LV have better results for color removal (85 to 35%), soluble solids ( 11 and 3%), DQO (90 and 86%) and turbidity (94 and 11%) than the treatment done by the textile industry. Sedimentation kinetics tests in presence of a magnet showed that photocatalysts are separated faster from aqueous environment than pure TiO2. Obtained results showed that magnetic photocatalysts have excellent photocatalytic activity and can be separated from the reaction environment on a simple and quick way when a magnetic field is applied.
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The barks generated from the wood processing industries are wastes generated in significant quantities, becoming interesting to have basic studies of their anatomical and chemical properties in order to make better use of this material. This study aimed to carry out anatomical studies, chemical and tannins from the barks of commercial clones of Eucalyptus. For this, permanent histological slides for anatomical characterization and percentage of cellular elements were prepared; and cellular elements were dissociated for biometry of the elements. The analyses were related to chemical extractives, ash, lignin, suberin, sugars, phenols, tannins, flavonoids and antioxidant activity of the extracts. The tannins were extracted in pure water and with water mixed with sodium sulfite, and were subsequently evaluated the properties by FT-IR. It was verified by the anatomical characterization and chemical quantification, the similarity between the clones. Regarding the biometrics of cellular elements, statistically significant differences were not observed for the following parameters: length and diameter of sieve tube, axial parenchyma diameter, and rays hight. The yield of condensed tannins and Stiasny index for studied clones are low, showing the infeasibility of using bark for the extraction of tannins to produce adhesives, however tannins and other bioactive phenolic compounds can be used in the pharmaceutical and cosmetics sectors due to its antioxidant potential. The spectrum of tannins is the same as the one found the literature. Due to the high yield of verified sugar, (around 46,68%) sugars are potencial products, with a high yield of glucose , it is interesting for application in biorefinery.
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The consumption of snack bars is based especially on the demand for practical and nutritious food. Coffee is highlighted for being appreciated and consumed worldwide, presenting elevated antioxidant activity, in addition to peculiar sensorial attributes. Therefore, it has great potential for use in many formulations. However, the success in the acceptance of a new product also derives from adequate marketing strategies. In this context, the present study aimed at evaluating the feasibility of introducing to the market a snack bar added with coffee, by means of sensorial acceptance and purchase intent of the consumers, in addition to identifying the best concept and the possible market segments. This work was a qualitative, by means of a focus group (content analysis), and quantitative research, by means of sensorial analysis and structures questionnaires (descriptive – frequency distribution, arithmetic mean, crosstabs and t test – and multivariate – cluster and discriminate analysis - statistical techniques). With the results, we showed that the main aspects considered by the consumers regarding the snack bar added with coffee. According to the qualitative evaluation, the consumer prefers packaging with matte colors ranging in the tones related to the coffee grain. The analysis of the quantitative data allows us to infer that the evaluations of the product regarding overall impression, purchase intent, preference and expectation before and after consuming the product are better for packaging containing the information “special coffee flavor – 100% arabic”. Regarding market segment, it was possible to conclude that, of the three extracted groups, the group of “healthy and conscious consumers” was the segment with higher potential for exploitation regarding purchase and consumption of the snack bar added with coffee.