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Aplicação e avaliação de critérios semi-empíricos para o desenvolvimento de novas ligas vítreas do sistema Ti-Cu-Ni
(Universidade Federal de São Carlos, 2013-06-26) Mendes, Marcio Andreato Batista; Kiminami, Claudio Shyinti; https://lattes.cnpq.br/5443002033733395; https://lattes.cnpq.br/7695641535327968
The selection of good glass forming compositions is not a simple undertaking and many groups work on models and theoretical approximations in order to predict or at least guide the laborious and expensive experimental pinpointing of compositions in a given system. The DEMa-UFSCar group , in partnership with the solidification group of the EESC/SMM-USP , have worked in semi-empirical criteria based on a combination of topological aspects (criterion λmin), electronegativity (criteria Δe) and enthalpy of mixing of the elements [criterion Log(RC)] to predict compositions with high Glass Forming Ability (GFA). These criteria have shown good results to predict compositions with high GFA. The aim of this thesis was to contribute to the efforts being made to improve the efficiency and to expand the applications of these proposed criteria. For this study, we used the Log (RC) criterion and the combined criteria λmin x Δe. Using these criteria, nine composition of the Ti-Cu-Ni system were selected and were processed in the laboratory, so the theoretical and experimental results were compared. The experimental results were also compared with the theoretical results of other criteria reported in the literature. This study was performed with the use of rapidly solidified ribbons and analyzed by thermal analysis (DSC), Xray diffraction (XRD) and statistical tools. The results showed that the proposed criteria have low correlation with the experimental results; and to increase that correlation we proposed some improvements in the criteria. Additionally, through another study it was possible to determine the first stages of devitrification of the amorphous structure and to compare them with the predictions of the criteria Log (RC) and λmin x Δe. For this, we selected 4 alloys of the Ti-Cu-Ni system and a study of crystallization kinetics was performed using transmission electron microscopy (TEM), DSC and XRD analyzes. It was revealed that the experimental results are consistent with the theoretical results partially.
Influência do período de molhamento, temperatura e concentração de inóculo de Pyricularia grisea na ocorrência da brusone em plântulas de trigo
(Universidade Federal de São Carlos, 2013-06-26) Storani, Waleska Del Pietro; Urashima, Alfredo Seiiti; https://lattes.cnpq.br/1289170266294665; https://lattes.cnpq.br/2319417739940887
Blast disease, caused by Magnaporthe grisea (anamorph Pyricularia grisea), is one of the main diseases of wheat and is disseminated throughout main producing states of the Country. It has been causing significant yield loss and is a limiting factor for the crop s expansion in central Brazil where the weather is highly favorable. The use of resistant cultivars can be influenced by weather conditions and concentration of inoculum. Chapter 1 of the present dissertation describes the influence of period of foliar wetness on the occurrence of blast in wheat seedlings in two experiments. The first one employed cultivars BH1146 (resistant) and BR40 (susceptible) inoculated with the Pyricularia isolate PR06- 03. In the second assay, the cultivars were BR18 (resistant) and Anahuac (susceptible) inoculated with the fungal isolate PR01-23. Five treatments were the period of wetness (6, 10, 14, 18 and 24h) in ten replications. Analysis was performed using a completely randomized design with a factorial plan of the treatments (five foliar wetness periods and 2 cultivars). Results showed that the minimum period needed for the development of the disease was 10 hours when inoculated with the isolate PR06-03. The longer the foliar wetness period the higher the incidence and severity of the disease regardless the resistance of cultivars. Chapter 2 aimed to determine the influence of the weather and concentration of P. grisea on the incidence and severity of blast. The experiment used totally randomized design with a factorial plan of the treatments: four concentrations (10³, 104, 105, 106 spores/ml) and two cultivars, ten repetitions. The wheat cultivars were BR18 (resistant) and Anahuac (susceptible) which were inoculated with 50ml of P. grisea suspension (isolate PR06-03) at the concentrations 10³, 104, 105, 106 spores/ml. The seedlings were submitted to temperatures of 22ºC and 28ºC for 18 hours of foliar wetness. The results showed that at 22ºC higher disease severity occurred on susceptible cultivar whereas the disease was the same for both cultivars at 28ºC. The resistant cultivar reacted like a susceptible when submitted to high temperature and high concentration of pathogen.
Regularização ambiental de propriedades agrícolas: transição de cenários
(Universidade Federal de São Carlos, 2013-06-26) Storani, Denis; Colato, Alexandre; https://lattes.cnpq.br/5460973924624757; https://lattes.cnpq.br/6384020342617941
The constant changes of the forest legislation in Brazil show the complexity in its interpretation and application by the farmers in their properties. Since the first Forest Code (FC) through the decree no. 23.793 from 1934, going through the creation of the New FC through the Federal Law no. 4.771 from 1965 to the Federal Law no. 12.651 from 2012 which formulated the previous one, there were significant changes on the concepts, parameters and on the application way on those standards according to the preservation and the natural sources management of the farms, however, for their regularization should be observed basically two kinds of restriction of the soil usage proposed by the forest law: the permanent preservation area (PPA) and the legal reserve (LR). Thus, the aim of this work was to analyze the transition of the scenes according to the environmental regularization of the farms of the FC from 1965 and FC from 2012, besides to create a timeline from 1934 to 2012, analyzing the main legislations about the creation of the FC diagrams from 1965 and FC from 2012, analyzing the actions which should be done to regulate the farm. It was verified that the FC from 1965 was effective for 47 years, but it had gone through more than 80 modifications in its original text being more constant in the 90 s and 2000 s, nevertheless more than 90% of the farms didn t respect it. The reform of the FC from 1965, consolidated only by the end of 2012 through the Federal Law no. 12.727 which converted the MP no. 571 changing definitely the Federal Law no. 12.651 from May, 25th aimed to modernize trying to pair the FC from 2012 to the new reality of the Brazilian agriculture, bringing new mechanisms and tools to make its application easier. Although these devices should be applied in a practical and simple way to attend the 5.175.636 farms in a two year deadline, taking the risk of disuse like the previous FC.