Sol-gel (solution-gelation) method was used to prepare Ni-Ti and Ni-Ti-Al catalysts for reforming of methane with carbon dioxide. This method, after optimizing the parameters such as hydrolysis and acid/alkoxide ratio, is able to make a Ni-Ti catalyst with a surface area as high as 426m2/g when calcined at 473K; but calcination at higher temperature lead to dramatic decrease in surface area. XRD, XPS, TEM and SEM were used to understand this change. Using a packed bed reactor, the catalysts were evaluated with the reforming reaction. It was found that the activity of the Ni-Ti catalyst increases with the Ni loading in the range of 1-10wt%. The reduction temperature has strong effect on activity of the reduced catalyst. Up to 973K, the activity increases with the reduction temperature; but after 973K, the activity decreases and become 0 when the temperature is over 1023K. The Ni-Ti catalyst also deactivated as 15% after 4h of time on stream. The XRD analysis shows that Ti3O5 formed in the catalyst after higher-temperature reduction as well as after the reaction for a period of time. The formation of Ti3O5 may render the catalyst to loss its activity. However, further study is expected to understand the mechanism. TG/DTA analysis shows that both Ni-Ti and Ni-Ti-Al catalysts had carbon deposition; but the latter maintained higher activity in a longer period of time.

As inspired by the coordination environment of nickel in NikR and NiSOD, imidazole ligands were incorporated into N2SNiII square planar complexes in order to investigate the electronic and structural features of NiII species containing both imidazole and thiolate ligation. Rare examples of nickel complexes containing such ligand sets in continuous tetradentate (N2N'S) and discontinuous (N2S---N') coordination were synthesized and characterized. A significant finding in these studies is that the plane of the imidazole ligand is oriented perpendicular to the N2SNi plane. Further investigations addressed the orientational preference and stereodynamic nature of flat monodentate ligands (L = imidazoles, pyridine and an N-heterocyclic carbene) bound to planar N2SNi moieties. The solid state molecular structures of planar [N2SNiL]n+ complexes accessed through bridge-splitting reactions of dimeric, thiolate-S bridged [N2SNi]2 complexes, reveal that the plane of the added monodentate ligand orients largely orthogonal to the N2SNiL square plane. Variable temperature 1H NMR characterization of dynamic processes and ground state isomeric ratios of imidazole complexes in their stopped exchange limiting spectra, readily correlate with DFT-guided interpretation of Ni-L rotational activation barriers. Full DFT characterization relates the orientation mainly to steric hindrance derived both from ligand and binding pocket. In the case of the imidazole ligands a minor electronic contribution derives from intramolecular electrostatic interactions (imidazole C-2 C-H[superscript delta]+- - S[superscript delta]- interaction). Our group has firmly established the versatility of the (bme-daco)2-, (bme-dach)2-, and (ema)[left arrow]- ligands to accommodate a number of metals (M = Ni, Zn, Cu, and Fe ), and have demonstrated reactivity of such N2S2M complexes occurs predominately at the S-thiolate sites. As vanadium is of interest for its biological, pharmacological and spectroscopic/analytical probe abilities, vanadyl analogues were explored as mimics of possible chelates formed from Cys-X-Cys binding sites in vivo. The structural and electronic changes from the incorporation of V=O2+ in such dianionic and tetraanionic N2S2 binding pockets is investigated and compared to Ni2+ and Zn2+ in similar N2S2 environments. The nucleophilicity of the S-thiolate in these systems is explored with alkylating agents and W(CO)x. Furthermore, the vanadyl interaction with the CGC peptide, the biological analogue of the tetraanionic N2S2 ligand, was produced and characterized by EPR; its W(CO)x adducts were indentified by ?(CO) infrared spectroscopy.

This study aims to experimentally explore the possibility to join the two pieces of low-carbon steel and Cu-Ni alloy as the cladding material into a thick clad steel plate during a Friction Stir Lap Welding¡]FSLW¡^process without a probe. Two methods are employed to enhance the welding strength. Firstly, a layer of nickel is coated on the low-carbon steel to prevent it from oxidizing during the welding process. Secondly, the surface of the low-carbon steel is knurled to increase the contact area between the welding surfaces. Experimental results show that Ni-coating can effectively prevent the generation of oxidation and improve the welding strength. According to the tensile test using a plate of Cu-Ni alloy with a thickness of 4 mm, the welding strength of the clad steel plate with Ni-coating is about 2.3 times greater than that without Ni-coating. Moreover, according to the impact test, the clad steel plate with Ni-coating can absorb more impact energy than that without Ni-coating. This difference increases with increasing thickness of the plate. It is also found that the welding strength at the center of joints using the Ni-coating is greater than that at the substrate of copper-nickel alloy. For the clad steel plate with knurling, since it is difficult to fill the gap between the patterns of knurling, the increase in the contact area between the welding surfaces has been offset. Hence, the welding strength of the clad steel plate with knurling is less than that with Ni-coating.

Partial oxidation of CH4, CO2 reforming of CH4, and oxidative CO2 reforming of CH4 to produce synthesis gas at 700°C over supported Ni catalysts have been studied. A Ni/Mg-Al catalyst was prepared by the solid phase crystallization (spc-) method starting from a hydrotalcite-type (HT) anionic precursor. From XRD analysis, only Ni0.5Mg2.5Al catalyst consists of the layered hydrotalcite-type structure; not Ni0.5Ca2.5Al and Ni/Al2O3 catalysts. By TPR test, the Ni0.5Mg2.5Al-HT catalyst requires a high reduction temperature than the Ni0.5Ca2.5Al catalyst. It implies that the Ni0.5Mg2.5Al-HT which has a layered structure shows the stronger interaction strength between the molecules. It might increase the resistance of coke formation on the surface of the catalyst. For the reaction tests, the Ni0.5Ca2.5Al showed the highest initial activity for synthesis gas production for all reactions; but, its activity was decreased quickly due to coke formation except during the partial oxidation of CH4. The Ni0.5Mg2.5Al-HT showed a relatively higher reactivity compared to the equilibrium level than Ni/Al2O3 catalyst; and it shows very stable reactivity than other catalysts. By TPO test, the Ni0.5Mg2.5Al-HT has the lower amount of coke formed during the reaction than the Ni0.5Ca2.5Al catalyst. It confirms that the Ni0.5Mg2.5Al-HT catalyst has stronger resistance to coke formation; and it leads to provide stable reactivity in any reforming conditions at high temperature. Therefore, the Ni0.5Mg2.5Al-HT catalyst was the most promising catalyst in terms of activity and stability for partial oxidation, CO2 reforming, and oxidative CO2 reforming of CH4. The Ni0.5Mg2.5Al-HT catalyst was used to investigate the CO2 reforming of CH4 kinetics. With increasing CH4 partial pressures at constant CO2 partial pressure, the rates of CH4 consumption were increased. However, with increasing CO2 partial pressure at constant CH4 partial pressure, CH4 consumption rates was increased at lower CO2 partial pressure, but turned to independent at higher CO2 partial pressure. When the partial pressure of H2 was increased, the CO formation rate was decreased; it confirmed that the reverse water-gas shift (RWGS) reaction was occurring during the CO2 reforming of CH4 reaction. In addition, the reaction kinetic expression was proposed when the CH4 dissociation step was considered as a rate-limiting step.

This work have served as a preliminary work for a more extensiveresearch on antimony- and nickel-doped tin dioxide electrodes used forozone generation in electrolytic reactions. The target has been to test themanufacturing process of Sb/Ni-doped SnO2 with spin-coating techniqueand succeed to make electrodes for anodic ozone evolution and tocharacterize them. Electrode manufacturing was made using sol-gelfrom chloride salts of tin, antimony and nickel, which were applied to atitanium substrate through spin-coating. The substrates were spun todifferent thickness followed by drying and baking of the substrate. A setof electrodes with three layers were made just with spin-coating, additionallya set of electrodes with twenty layers were made with bothspin-coating and dip-coating. To characterize physical properties of theelectrodes, x-ray diffraction, scanning electron microscopy and transmissionelectron microscopy were conducted. Electrochemical measurementswere made in open beakers with a platinum cathode andsulphuric acid electrolyte using a galvanostatic measurement with afixed current. To measure the ozone evolution the optical absorbancedifference from the electrolyte compared to a clean electrolyte wasmeasured, this however only measures the amount of aqueous ozonepresent. Assembling of SnO2 electrodes for ozone evolution was successful.For the three-layered electrodes the absorbance readings wereinconclusive but with the twenty-layered electrodes there was a smell ofozone present within the electrolyte and absorbance reading of the dipcoatedelectrode presented a clear peak for ozone.

Applied research project (D. Min.)--School of Theology and Missions, Oral Roberts University, 2006. / Includes abstract and vita. Translated from Korean. Includes bibliographical references (leaves 156-163).

Applied research project (D. Min.)--School of Theology and Missions, Oral Roberts University, 2006. / Includes abstract and vita. Includes bibliographical references (leaves 158-165).

Zugl.: Köln, Universiẗat, Diss., 2008.

Orientador: Carlos Roberto Grandini / Banca: Maria Cristina R. Alves Rezende / Banca: Katia Regina Cardoso / O Programa de Pós Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi / Resumo: Dentre os materiais avançados que a Ciência e Engenharia de Materiais vêm desenvolvendo estão os biomateriais. Há muito, estes são utilizados para reparar partes do corpo danificadas ou deterioradas, mas em função da enorme complexidade dos tecidos vidos e do organismo como um todo, é comum ocorrerem falhas a curto ou longo prazo. No entando, a demanda por esses materiais tende a aumentar, justificando a importância de mais pesquisas nesta área. Existem muitos dispositivos médicos e odontológicos confeccionados com a liga Ti-Ni em função de suas propriedades de memória de forma, superelasticidade e biocompatibilidade. No entando, o elemento níquel é muito tóxico em níveis elevados. A liga Ti-5Ni é o objeto deste estudo e foi preparada a partir da fusão dos metais precursores, tratada térmica e mecanicamente, além de ser dopada com oxigênio. Em cada condição, foi caracterizada em termos de sua composição química, densidade, difração de raios X e microscopia óptica. Também foram analisadas propriedades como microdureza, módulo de elasticidade e biocompatibilidade. As micrografias mostraram que a microestrutura das amostras são dependentes dos tratamentos térmicos e que propriedades tais como microdureza e módulo de elasticidade sofrem variações de acordo com a microestrutura e quantidade de oxigênio. O refinamento pelo método de Rietveld permitiu averiguar as variações nos parâmetros de rede com a inserção de níquel e oxigênio ao titânio. Foram obtidos resultados satisfatórios nos testes de biocompatibilidade, concluindo que a liga apresenta bom potenciala como biomaterial / Abstract: Among the advanced materials that are developing by science and materials and materials engineering are the biomaterials. There are a lot, these are used to repair damaged or deteriored parts of the body, but in the function of the enormous complexity of living tissue and organism as a whole, are common failures in the short or long term. However, the demand for these materials tends to increase, justifying the importance of further research in this area. There are many medical and dental devices made with Ti-Ni alloy due to its properties of shape memory, supereslaticity and biocompatibility. However, the nickel element is very toxic at high levels. Ti-5Ni alloy is the object of this study and was prepared from arc-melting and heat mechanically treated, besides being doped with oxygen. In each condition, it was characterized in terms of its chemical composition, density, x-ray diffraction and optical microscopy. Were also examined properties such as microhardness, elasticity modulus and biocompatibility. The micrographies showed that the microstructure of samples is dependent on the heat treatment and properties such as microhardness and elasticity modulus suffer variations according to the microstructure and oxygen amount. Refinement by Rietveld method allowed investigating changes in lattice parameters with the addition of nickel and oxygen to titanium. Satisfactory results were obtained in biocompatibility tests, concluding that the alloy presents good potential as a biomaterial / Mestre

Submitted by Guilherme Orsetti (guilherme.orsetti@ufvjm.edu.br) on 2016-07-14T19:37:31Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) andressa_ aparecida_goncalves.pdf: 2921232 bytes, checksum: 7bb7b4fc7e6bed0489470006df3aeb04 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-07-18T14:56:29Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) andressa_ aparecida_goncalves.pdf: 2921232 bytes, checksum: 7bb7b4fc7e6bed0489470006df3aeb04 (MD5) / Made available in DSpace on 2016-07-18T14:56:29Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) andressa_ aparecida_goncalves.pdf: 2921232 bytes, checksum: 7bb7b4fc7e6bed0489470006df3aeb04 (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / Funda??o de Amparo ? Pesquisa do estado de Minas Gerais (FAPEMIG) / Nanopart?culas bimet?licas (bNPs) de Ni-Fe estabilizadas com s?lica (Ni-Fe/SIL) e quitosana (Ni-Fe/QUI) foram sintetizadas e caracterizadas para aplica??o em ?gua contaminada para remo??o da nimesulida (NMS). Para os ensaios em batelada em solu??es aquosas, fatores que afetam a remo??o NMS tais como a concentra??o inicial de NMS e a dosagem de Ni-Fe/SIL e Ni-Fe/QUI foram investigados sistematicamente. A remo??o completa da NMS foi obtida em 15 min de rea??o ao utilizar-se as bNPs 8%Ni-Fe/SIL, na velocidade 250 rpm, dose de 0,6g e concentra??o inicial de 50 mg L-1. J? a remo??o completa ao utilizar-se as bNPs 17%Ni- Fe/QUI foi obtida ap?s 17,5 min de rea??o de 40 mg L-1 de NMS com 0,8 g de 17%Ni- Fe/QUI e agita??o de 250 rpm. Como esperado para uma rea??o heterog?nea realizada em batelada, sob vigorosa agita??o, foi verificado que a taxa de remo??o aumentou com o aumento da concentra??o inicial da NMS e da dosagem de 8%Ni-Fe/SIL e 17%Ni-Fe/QUI. Foi realizado um estudo do efeito da velocidade de agita??o do sistema, verificando que este ? um fator que influencia diretamente na taxa de remo??o. O estudo de remo??o na presen?a e na aus?ncia de oxig?nio dissolvido revelou que a presen?a deste ?ltimo exerce uma pequena influ?ncia no processo de remo??o. Um estudo comparativo da remo??o utilizando a bNPs na presen?a e na aus?ncia dos agentes estabilizantes foi realizado nas mesmas propor??es, sendo verificado que os n?veis de remo??o foram superiores para o sistema em presen?a de estabilizantes. A an?lise do subproduto formado da NMS mostrou que este ? menos t?xico que o composto original. O presente trabalho demonstra que o processo de tratamento redutivo alternativo fazendo uso de nanopart?culas bimet?licas contendo Fe e Ni ? muito promissor para a elimina??o da NMS. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Qu?mica, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / ABSTRACT Fe-Ni bimetallic nanoparticles stabilized with silica (Ni-Fe/SIL) and chitosan (Ni-Fe/CS) were synthesized and characterized for use in contaminated water for removal of nimesulide (NMS). For the test batch in aqueous solutions, factors affecting the removal of drugs such as the initial concentration of NMS and dosage of Ni-Fe/SIL and Ni-Fe/CS were investigated systematically. The complete removal of the NMS was obtained in 15 min of reaction using up the bNPS 8%Ni-Fe/SIL speed 250 rpm, initial concentration of 50 mg L- and 0.6g dose. Since complete removal when using bNPs 17%Ni-Fe/CS was obtained after 17.5 minutes of reaction 40 mg L-1 NMS with 0.8 g of 17%Ni-Fe/CS and stirring 250 rpm. As expected for a heterogeneous reaction carried out in batch, under vigorous stirring, it was found that the removal rate increased with the increase of the initial concentration of the drugs and dosage of Ni-Fe/SIL and Ni-Fe/CS. A study of the effect of system stirring speed was carried out by checking that this is a factor that directly influence the removal rate. The removal of the presence and in the absence of dissolved oxygen showed that the presence of the latter exerts a small influence on the removal process. A comparison of removal using the bNPs in the presence and in the absence of stabilizers was performed in the same proportions, and found that the removal rates were higher for the system in the presence of stabilizers. The analysis of the byproduct formed from the NMS showed that it is less toxic than the parent compound. The present work demonstrates that the reductive treatment process alternative making use of bimetallic nanoparticles containing Fe and Ni is very promising for the elimination of NMS.