The present work reports a study of the effects of the compositions, and various catalytic additives and nanostructuring by high-energy ball milling, on the hydrogen storage properties of LiBH4, NaBH4, LiNH2 and LiAlH4 complex hydrides and their composites. The composites of (NaBH4+2Mg(OH)2) and (LiBH4+2Mg(OH)2) without and with nanometric nickel (n-Ni) added as a potential catalyst were synthesized by ball milling. The effect of the addition of 5 wt.% nanometric Ni on the dehydrogenation behavior of both the NaBH4-and LiBH4-based composites is rather negligible. In the (LiNH2+nMgH2) system, the phase transformations occurring as a function of the ball milling energy injected into the hydride system (LiNH2+nMgH2), having molar ratios n=0.5 to 2.0, have been thoroughly studied. The milling energy is estimated by a semi-empirical method. The results show that for the molar ratios n<1.0 three new phases such as LiH, amorphous Mg(NH2)2 (a-Mg(NH2)2) and Li2Mg(NH)2 are formed during ball milling depending on the injected energy. For the molar ratios n≥1.0 the new phase of MgNH forms whose formation is accompanied by a profound release of hydrogen. Addition of 5 %wt. KH can improve desorption rate of the LiNH2+0.5 MgH2 system. Furthermore this hydride system can be nearly fully rehydrogenated at 200°C and 50 bar H2 pressure. LiAlH4 containing 5 wt.% of nanometric Fe and Ni shows a profound mechanical dehydrogenation by continuously desorbing hydrogen (H2) during ball milling. X-ray diffraction studies show that Fe and Ni ions dissolve in the lattice, replacing the Al ions and forming a substitutional solid solution. Both Fe and Ni decrease the activation energies of stage I and II , but stage I is more sensitive to the particle size . The addition of 5 wt.% nano-size “interstitial compound” (n-TiC, n-TiN and n-ZrC) shows a continuous desorption of H2 is observed during high energy milling. Mechanical dehydrogenation rate of the doped samples increases noticeably during high-energy ball milling in the order of TiN > TiC > ZrC. The interstitial compound additives are able to strongly reduce the activation energy of Stage II dehydrogenation but do not substantially affect the apparent activation energy of Stage I .

The present work reports a study of the effects of the compositions, and various catalytic additives and nanostructuring by high-energy ball milling, on the hydrogen storage properties of LiBH4, NaBH4, LiNH2 and LiAlH4 complex hydrides and their composites. The composites of (NaBH4+2Mg(OH)2) and (LiBH4+2Mg(OH)2) without and with nanometric nickel (n-Ni) added as a potential catalyst were synthesized by ball milling. The effect of the addition of 5 wt.% nanometric Ni on the dehydrogenation behavior of both the NaBH4-and LiBH4-based composites is rather negligible. In the (LiNH2+nMgH2) system, the phase transformations occurring as a function of the ball milling energy injected into the hydride system (LiNH2+nMgH2), having molar ratios n=0.5 to 2.0, have been thoroughly studied. The milling energy is estimated by a semi-empirical method. The results show that for the molar ratios n<1.0 three new phases such as LiH, amorphous Mg(NH2)2 (a-Mg(NH2)2) and Li2Mg(NH)2 are formed during ball milling depending on the injected energy. For the molar ratios n≥1.0 the new phase of MgNH forms whose formation is accompanied by a profound release of hydrogen. Addition of 5 %wt. KH can improve desorption rate of the LiNH2+0.5 MgH2 system. Furthermore this hydride system can be nearly fully rehydrogenated at 200°C and 50 bar H2 pressure. LiAlH4 containing 5 wt.% of nanometric Fe and Ni shows a profound mechanical dehydrogenation by continuously desorbing hydrogen (H2) during ball milling. X-ray diffraction studies show that Fe and Ni ions dissolve in the lattice, replacing the Al ions and forming a substitutional solid solution. Both Fe and Ni decrease the activation energies of stage I and II , but stage I is more sensitive to the particle size . The addition of 5 wt.% nano-size “interstitial compound” (n-TiC, n-TiN and n-ZrC) shows a continuous desorption of H2 is observed during high energy milling. Mechanical dehydrogenation rate of the doped samples increases noticeably during high-energy ball milling in the order of TiN > TiC > ZrC. The interstitial compound additives are able to strongly reduce the activation energy of Stage II dehydrogenation but do not substantially affect the apparent activation energy of Stage I .

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Soybean is the main oilseed crop produced in the world, and many factors can affect the soybean yield, including the diseases and insects attacks. Thus, the seed treatment with fungicides and insecticides is another alternative for ensuring the establishment of appropriate plant stands in the field. In addition, is common the use of soybean seed coating with polymers to improve the incorporation of other products used in the seed treatment. Therefore, the aim of this study was to evaluate the physiological and health quality of soybean seeds treated with fungicide, insecticide, micronutrients and polymer. The study was developed in two chapters, being the first entitled "Physiological, and health quality and yield of soybean seeds with chemical treatment", which aims to evaluate the effect of soybean seed treatment on the physiological and health quality, as well as, on the field performance of seeds. In the second chapter, entitled "Soybean seeds chemical treatment on the physiological and health quality during storage" aimed to evaluate the effect of seed treatment with fungicide, insecticide micronutrients and polymer, during the storage period. The chemical treatment of soybean seeds is a suitable tool to improve the physiological performance of soybean seeds and the plants establishing in the field. Furthermore, the use of these products helped to maintain physiological and health quality of seeds during storage. / A soja é a principal oleaginosa cultivada no mundo, sendo que diversos fatores podem afetar seu potencial de rendimento, incluindo o ataque de doenças e insetos. Assim, o tratamento de sementes de soja com fungicidas e inseticidas é mais uma alternativa para assegurar o estabelecimento de uma população adequada de plantas no campo. Além desses produtos, tem-se difundido também o uso recobrimento de sementes com polímeros, visando melhorar a incorporação dos demais produtos vinculados às sementes. Diante disso, desenvolveu-se esse estudo com objetivo de avaliar o desempenho fisiológico e sanitário de sementes de soja submetidas ao tratamento químico com fungicida, inseticida, micronutrientes e polímero. O trabalho consiste de dois capítulos sendo o primeiro intitulado Qualidade fisiológica, sanitária e produtividade de sementes de soja submetidas ao tratamento químico , o qual tem por objetivo avaliar o efeito tratamento de sementes de soja no desempenho fisiológico e sanitário das sementes, bem como, no rendimento a campo. No segundo capítulo, intitulado Tratamento químico de sementes de soja sobre a qualidade fisiológica e sanitária durante o período de armazenamento objetivou-se avaliar o efeito do tratamento de sementes com fungicida, inseticida, micronutrientes e polímero, ao longo do período de armazenamento. O tratamento químico de sementes de soja demonstrou ser uma ferramenta adequada melhorando o desempenho fisiológico das sementes de soja e o estabelecimento de plantas no campo. Além disso, a utilização desses produtos auxiliou na manutenção da qualidade fisiológica e sanitária das sementes de soja ao longo do armazenamento.