Efeito do tratamento térmico nas propriedades mecânicas e resistência ao desgaste de um ferro fundido branco multicomponente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Manejo integrado da ferrugem asiática da soja na região de Jaboticabal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

ASIAN SOYBEAN RUST INTEGRATED MANAGEMENT POTENTIAL: DISEASE SEVERITY, PLANT DEVELOPMENT AND YIELD COMPONENTS, CULTIVAR MG/BR-46 (CONQUISTA)

Soybean rust caused by Phakopsora pachyrhizi Sydow & P. Sydow is one of the major diseases of the soybean crop. The aim of this study was to evaluate the effects of sowing dates, plant populations and reduced doses of fungicides on soybean rust severity and its effects on plant development and yield, cultivar MG/BR46 (Conquista). Field experiments were conducted in the 2009/2010 and 2010/2011 harvests, under natural rust infestation of soybean rust. As from the appearance of the first disease symptoms, also began the fungicide spraying and the disease severity assessments. To understand the nature and extent of the effects of different treatments, a multivariate analysis of factors was applied. For the majority of the agronomic characters and factors, one-third to two-thirds of their variability can be explained by changes in plant populations or by differences in the fungicide treatments, and the remainder, was explained by sowing date variations. The fungicide treatments and sowing dates are determinants in disease severity and its interference on crop productivity. The characters of plant growth are more dependent on plant population variations. Treatments with azoxystrobina + ciproconazol promoted smaller disease severities, reflecting in productivity increase. The plant populations can be reduced up to 160.000 plants ha(-1) without losses in the disease control and the soybean yield. In general, the earliest sowings provided increase in the plant development, although the rust control was less efficient.

Caracterização molecular, citogenética e fenotípica de acessos do Complexo Saccharum para fins de introgressão genética

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Artificial neural networks applied to bandsawing process control

In the search for productivity increase, industry has invested on the development of intelligent, flexible and self-adjusting method, capable of controlling processes through the assistance of autonomous systems, independently whether they are hardware or software. Notwithstanding, simulating conventional computational techniques is rather challenging, regarding the complexity and non-linearity of the production systems. Compared to traditional models, the approach with Artificial Neural Networks (ANN) performs well as noise suppression and treatment of non-linear data. Therefore, the challenges in the wood industry justify the use of ANN as a tool for process improvement and, consequently, add value to the final product. Furthermore, Artificial Intelligence techniques such as Neuro-Fuzzy Networks (NFNs) have proven effective, since NFNs combine the ability to learn from previous examples and generalize the acquired information from the ANNs with the capacity of Fuzzy Logic to transform linguistic variables in rules.

Análise do perfil de dureza e microestrutura de um aço forjado AISI A2 submetido a tratamento térmico com resfriamento em água

Due to the large use of steel in several processes around the world, there is the increasingly concern to find new materials and/or optimization and improvement of the processes, as the need to reduce the cost and a productivity increase in the primary industry, such as the siderurgy. The rolling is the most used mechanical process in the world and therefore is required the development of new tools in high volume and with optimum characteristics to support the market demand. Forged rolls used are for rolling. These rolls have heat treatment that has the purpose to achieve the appropriated mechanical properties to support the variables of the rolling process. The objective of this work is to analyze the hardness profile and the microstructure a tool steel similar to AISI A2, forged in an opened die process and submitted to heat treatment with water-cooling. The results allowed plotting a hardness profile and performing a microstructure analysis, and whereby to confirm that the heat treatment is not a quenching, but it is a material beneficiation by the hardening of superficial layer, since there is no martensitic microstructure. Therefore, this paper provides the support to future studies about the possibility to perform enhancements in this thermal heat made in the rolls produced at Gerdau Plant in Pindamonhangaba

Análise do perfil de dureza e microestrutura de um aço forjado AISI A2 submetido a tratamento térmico com resfriamento em água

Due to the large use of steel in several processes around the world, there is the increasingly concern to find new materials and/or optimization and improvement of the processes, as the need to reduce the cost and a productivity increase in the primary industry, such as the siderurgy. The rolling is the most used mechanical process in the world and therefore is required the development of new tools in high volume and with optimum characteristics to support the market demand. Forged rolls used are for rolling. These rolls have heat treatment that has the purpose to achieve the appropriated mechanical properties to support the variables of the rolling process. The objective of this work is to analyze the hardness profile and the microstructure a tool steel similar to AISI A2, forged in an opened die process and submitted to heat treatment with water-cooling. The results allowed plotting a hardness profile and performing a microstructure analysis, and whereby to confirm that the heat treatment is not a quenching, but it is a material beneficiation by the hardening of superficial layer, since there is no martensitic microstructure. Therefore, this paper provides the support to future studies about the possibility to perform enhancements in this thermal heat made in the rolls produced at Gerdau Plant in Pindamonhangaba

Land use policies and practices for reducing vulnerability in rural Tajikistan

Tajikistan, with 93% of its surface area taken up by mountains and 65% of its labor force employed in agriculture, is judged to be highly vulnerable to risks, including climate change risks and food insecurity risks. The article examines a set of land use policies and practices that can be used to mitigate the vulnerability of Tajikistan’s large rural population, primarily by increasing family incomes. Empirical evidence from Tajikistan and other CIS countries suggests that families with more land and higher commercialization earn higher incomes and achieve higher well-being. The recommended policy measures that are likely to increase rural family incomes accordingly advocate expansion of smallholder farms, improvement of livestock productivity, increase of farm commercialization through improvement of farm services, and greater diversification of both income sources and the product mix. The analysis relies for supporting evidence on official statistics and recent farm surveys. Examples from local initiatives promoting sustainable land management practices and demonstrating the implementation of the proposed policy measures are presented.

Carbon and oxygen isotope data for carbonates and benthic foraminifers from ODP Hole 113-689B

At Ocean Drilling Program Site 689 (Maud Rise, Southern Ocean), d18O records of fine-fraction bulk carbonate and benthic foraminifers indicate that accelerated climate cooling took place following at least two closely spaced early late Eocene extraterrestrial impact events. A simultaneous surface-water productivity increase, as interpreted from d13C data, is explained by enhanced water-column mixing due to increased latitudinal temperature gradients. These isotope data appear to be in concert with organic-walled dinoflagellate-cyst records across the same microkrystite-bearing impact-ejecta layer in the mid-latitude Massignano section (central Italy). In particular, the strong abundance increase of Thalassiphora pelagica is interpreted to indicate cooling or increased productivity at Massignano. Because impact-induced cooling processes are active on time scales of a few years at most, the estimated 100 k.y. duration of the cooling event appears to be too long to be explained by impact scenarios alone. This implies that a feedback mechanism, such as a global albedo increase due to extended snow and ice cover, may have sustained impact-induced cooling for a longer time after the impacts.

Geochemistry, sediment components, and paleoproductivity reconstruction for the Miocene to early Pliocene sediments

We reconstruct paleoproductivity at three sites in the Atlantic Ocean (Ocean Drilling Program Sites 982, 925, and 1088) to investigate the presence and extent of the late Miocene to early Pliocene 'biogenic bloom' from 9 to 3 Ma. Our approach involves construction of multiple records including benthic foraminiferal and CaCO3 accumulation rates, Uvigerina counts, dissolution proxies, and geochemical tracers for biogenic and detrital fluxes. This time interval also contains the so-called late Miocene carbon isotope shift, a well-known decrease in benthic foraminiferal d13C values. We find that the timing of paleoproductivity maxima differs among the three sites. At Site 982 (North Atlantic), benthic foraminifera and CaCO3 accumulation were both at a maximum at ~5 Ma, with smaller peaks at ~6 Ma. The paleoproductivity maximum was centered earlier (~6.6-6.0 Ma) in the tropical Atlantic (Site 925). In the South Atlantic (Site 1088), paleoproductivity increased even earlier, between 8.2 Ma and 6.2 Ma, and remained relatively high until ~5.4 Ma. We note that there is some overlap between the interval of maximum productivity between Sites 925 and 1088, as well as the minor productivity increase at Site 982. We conclude that the paleoproductivity results support hypotheses aiming to place the biogenic bloom into a global context of enhanced productivity. In addition, we find that at all three sites the d13C shift is accompanied by carbonate dissolution. This observation is consistent with published studies that have sought a relationship between the late Miocene carbon isotope shift and carbonate preservation.

Dinoflagellate cyst assemblages, Mg/Ca based reconstructed temperatures, stable carbon isotopes, and geochemical parameters of sediment core GeoB9508-5

In order to investigate a possible connection between tropical northeast (NE) Atlantic primary productivity, Atlantic meridional overturning circulation (AMOC), and drought in the Sahel region during Heinrich Stadial 1 (HS1), we used dinoflagellate cyst (dinocyst) assemblages, Mg/Ca based reconstructed temperatures, stable carbon isotopes (d13C) and geochemical parameters of a marine sediment core (GeoB 9508-5) from the continental slope offshore Senegal. Our results show a two-phase productivity pattern within HS1 that progressed from an interval of low marine productivity between ~ 19 and 16 kyr BP to a phase with an abrupt and large productivity increase from ~ 16 to 15 kyr BP. The second phase is characterized by distinct heavy planktonic d13C values and high concentrations of heterotrophic dinocysts in addition to a significant cooling signal based on reconstructions of past sea surface temperatures (SST). We conclude that productivity variations within HS1 can be attributed to a substantial shift of West African atmospheric processes. Taken together our results indicate a significant intensification of the North East (NE) trade winds over West Africa leading to more intense upwelling during the last millennium of HS1 between ~ 16 and 15 kyr BP, thus leaving a strong imprint on the dinocyst assemblages and sea surface conditions. Therefore, the two-phase productivity pattern indicates a complex hydrographic setting suggesting that HS1 cannot be regarded as uniform as previously thought.

Geochemistry of sediments cores in the Mediterranean Sea

We investigated five time-equivalent core sections (180-110 kyr BP) from the Balearic Sea (Menorca Rise), the easternmost Levantine Basin and southwest, south, and southeast of Crete to reconstruct spatial patterns of productivity during deposition of sapropels S5 and S6 in the Mediterranean Sea. Our indicators are Ba, total organic carbon and carbonate contents. We found no indications of Ba remobilization within the investigated core intervals, and used the accumulation rate of biogenic Ba to compute paleoproductivity. Maximum surface water productivity (up to 350 g C/m2/yr) was found during deposition of S5 (isotope stage 5e) but pronounced spatial variability is evident. Coeval sediment intervals in the Balearic Sea show very little productivity change, suggesting that chemical and biological environments in the eastern and western Mediterranean basins were decoupled in this interval. We interpret the spatial variability as the result of two different modes of nutrient delivery to the photic zone: riverderived nutrient input and shoaling of the pycnocline/nutricline to the photic zone. The productivity increase during the formation of S6 was moderate compared to S5 and had a less marked spatial variability within the study area of the eastern Mediterranean Sea. Given that S6 formed during a glacial interval, glacial boundary conditions such as high wind stress and/or cooler surface water temperatures apparently favored lateral and vertical mixing and prevented the development of the spatial gradients within the Eastern Mediterranean Sea (EMS) observed for S5. A non-sapropel sediment interval with elevated Ba content and depleted 18O/16O ratios in planktonic foraminifer calcite was detected between S6 and S5 that corresponds to the weak northern hemisphere insolation maximum at 150 kyr. At this time, productivity apparently increased up to five times over surrounding intervals, but abundant benthic fauna show that the deep water remained oxic. Following our interpretation, the interval denotes a failed sapropel, when a weaker monsoon did not force the EMS into permanent stratification. The comparison of interglacial and glacial sapropels illustrates the relevance of climatic boundary conditions in the northern catchment in determining the facies and spatial variability of sapropels within the EMS.

UM ESTUDO PRELIMINAR DAS INFLUÊNCIAS DO MERCADO DE COMMODITIES NA VARIAÇÃO DO CUSTO DA ALIMENTAÇÃO DO TRABALHADOR: ANÁLISE DE RISCO DA SEGURANÇA ALIMENTAR E NUTRICIONAL

A Segurança Alimentar e Nutricional do trabalhador brasileiro é uma das formas de garantia de saúde e conseqüente aumento de produtividade refletido pelo compromisso do PAT Programa de Alimentação do Trabalhador que completou 30 anos em 2006. O objetivo do estudo é relacionar a variação de preços das commodities de alimentos presentes na refeição do trabalhador de acordo com o sistema normativo do PAT, identificando possíveis conseqüências negativas à Segurança Alimentar do Trabalhador no Brasil. A metodologia, por meio da análise de regressão múltipla, utiliza os dados de ICV Índice de Custo de Vida - de alimentação fora do domicílio como proxy a alimentação do trabalhador. Os resultados sugerem que os alimentos que apresentaram variação negativa com os tipos de refeições analisadas, como a carne suína e a soja, podem ser substituídos por outro valor nutricional semelhante como a carne bovina, o frango e o óleo de milho. Apenas a variação do preço do feijão foi seguida pelo aumento do preço do prato comercial, cuja alternativa é a mudança na maneira de oferecer a refeiç ão ao trabalhador, como os restaurantes por quilo. Diante do cenário exposto, há indícios de que a variação de preços dos alimentos no mercado de commodities teria pouca influência no preço final das refeições, mas a discussão em torno da futura escassez de oferta de alimentos devido ao aumento da população mundial e a mudança dos padrões alimentares com as sociedades urbanizadas insere o risco da SAN no contexto político e econômico da nutrição.(AU)

UM ESTUDO PRELIMINAR DAS INFLUÊNCIAS DO MERCADO DE COMMODITIES NA VARIAÇÃO DO CUSTO DA ALIMENTAÇÃO DO TRABALHADOR: ANÁLISE DE RISCO DA SEGURANÇA ALIMENTAR E NUTRICIONAL

A Segurança Alimentar e Nutricional do trabalhador brasileiro é uma das formas de garantia de saúde e conseqüente aumento de produtividade refletido pelo compromisso do PAT Programa de Alimentação do Trabalhador que completou 30 anos em 2006. O objetivo do estudo é relacionar a variação de preços das commodities de alimentos presentes na refeição do trabalhador de acordo com o sistema normativo do PAT, identificando possíveis conseqüências negativas à Segurança Alimentar do Trabalhador no Brasil. A metodologia, por meio da análise de regressão múltipla, utiliza os dados de ICV Índice de Custo de Vida - de alimentação fora do domicílio como proxy a alimentação do trabalhador. Os resultados sugerem que os alimentos que apresentaram variação negativa com os tipos de refeições analisadas, como a carne suína e a soja, podem ser substituídos por outro valor nutricional semelhante como a carne bovina, o frango e o óleo de milho. Apenas a variação do preço do feijão foi seguida pelo aumento do preço do prato comercial, cuja alternativa é a mudança na maneira de oferecer a refeiç ão ao trabalhador, como os restaurantes por quilo. Diante do cenário exposto, há indícios de que a variação de preços dos alimentos no mercado de commodities teria pouca influência no preço final das refeições, mas a discussão em torno da futura escassez de oferta de alimentos devido ao aumento da população mundial e a mudança dos padrões alimentares com as sociedades urbanizadas insere o risco da SAN no contexto político e econômico da nutrição.(AU)

UM ESTUDO PRELIMINAR DAS INFLUÊNCIAS DO MERCADO DE COMMODITIES NA VARIAÇÃO DO CUSTO DA ALIMENTAÇÃO DO TRABALHADOR: ANÁLISE DE RISCO DA SEGURANÇA ALIMENTAR E NUTRICIONAL

A Segurança Alimentar e Nutricional do trabalhador brasileiro é uma das formas de garantia de saúde e conseqüente aumento de produtividade refletido pelo compromisso do PAT Programa de Alimentação do Trabalhador que completou 30 anos em 2006. O objetivo do estudo é relacionar a variação de preços das commodities de alimentos presentes na refeição do trabalhador de acordo com o sistema normativo do PAT, identificando possíveis conseqüências negativas à Segurança Alimentar do Trabalhador no Brasil. A metodologia, por meio da análise de regressão múltipla, utiliza os dados de ICV Índice de Custo de Vida - de alimentação fora do domicílio como proxy a alimentação do trabalhador. Os resultados sugerem que os alimentos que apresentaram variação negativa com os tipos de refeições analisadas, como a carne suína e a soja, podem ser substituídos por outro valor nutricional semelhante como a carne bovina, o frango e o óleo de milho. Apenas a variação do preço do feijão foi seguida pelo aumento do preço do prato comercial, cuja alternativa é a mudança na maneira de oferecer a refeiç ão ao trabalhador, como os restaurantes por quilo. Diante do cenário exposto, há indícios de que a variação de preços dos alimentos no mercado de commodities teria pouca influência no preço final das refeições, mas a discussão em torno da futura escassez de oferta de alimentos devido ao aumento da população mundial e a mudança dos padrões alimentares com as sociedades urbanizadas insere o risco da SAN no contexto político e econômico da nutrição.(AU)