1 resultado para 1545
em Universidade Federal do Rio Grande do Norte(UFRN)
Filtro por publicador
- Repository Napier (1)
- Aberdeen University (5)
- Aberystwyth University Repository - Reino Unido (1)
- Academic Research Repository at Institute of Developing Economies (1)
- Acceda, el repositorio institucional de la Universidad de Las Palmas de Gran Canaria. España (3)
- AMS Tesi di Dottorato - Alm@DL - Università di Bologna (2)
- Andina Digital - Repositorio UASB-Digital - Universidade Andina Simón Bolívar (1)
- Aquatic Commons (1)
- Archimer: Archive de l'Institut francais de recherche pour l'exploitation de la mer (2)
- Archive of European Integration (1)
- Archivo Digital para la Docencia y la Investigación - Repositorio Institucional de la Universidad del País Vasco (2)
- Aston University Research Archive (2)
- Biblioteca de Teses e Dissertações da USP (1)
- Biblioteca Digital | Sistema Integrado de Documentación | UNCuyo - UNCUYO. UNIVERSIDAD NACIONAL DE CUYO. (1)
- Biblioteca Digital da Câmara dos Deputados (2)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (17)
- Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP) (4)
- Biblioteca Digital de Artesanías de Colombia (1)
- Biblioteca Digital de la Universidad Católica Argentina (1)
- Biblioteca Digital Loyola - Universidad de Deusto (25)
- Biblioteca Valenciana Digital - Ministerio de Educación, Cultura y Deporte - Valencia - Espanha (18)
- BORIS: Bern Open Repository and Information System - Berna - Suiça (74)
- Boston University Digital Common (1)
- Bucknell University Digital Commons - Pensilvania - USA (1)
- Bulgarian Digital Mathematics Library at IMI-BAS (1)
- CaltechTHESIS (1)
- Cámara de Comercio de Bogotá, Colombia (1)
- Cambridge University Engineering Department Publications Database (11)
- CentAUR: Central Archive University of Reading - UK (32)
- Chinese Academy of Sciences Institutional Repositories Grid Portal (24)
- Cochin University of Science & Technology (CUSAT), India (1)
- Comissão Econômica para a América Latina e o Caribe (CEPAL) (5)
- CORA - Cork Open Research Archive - University College Cork - Ireland (1)
- Corvinus Research Archive - The institutional repository for the Corvinus University of Budapest (3)
- Dalarna University College Electronic Archive (2)
- Digital Archives@Colby (1)
- Digital Commons - Michigan Tech (1)
- Digital Commons at Florida International University (2)
- DigitalCommons@The Texas Medical Center (1)
- DigitalCommons@University of Nebraska - Lincoln (1)
- Digitale Sammlungen - Goethe-Universität Frankfurt am Main (8)
- Duke University (18)
- eResearch Archive - Queensland Department of Agriculture; Fisheries and Forestry (2)
- FUNDAJ - Fundação Joaquim Nabuco (1)
- Gallica, Bibliotheque Numerique - Bibliothèque nationale de France (French National Library) (BnF), France (25)
- Greenwich Academic Literature Archive - UK (6)
- Harvard University (1)
- Helda - Digital Repository of University of Helsinki (2)
- Indian Institute of Science - Bangalore - Índia (8)
- Instituto Nacional de Saúde de Portugal (1)
- Instituto Politécnico de Santarém (1)
- Instituto Politécnico do Porto, Portugal (4)
- Instituto Superior de Psicologia Aplicada - Lisboa (1)
- Livre Saber - Repositório Digital de Materiais Didáticos - SEaD-UFSCar (1)
- Lume - Repositório Digital da Universidade Federal do Rio Grande do Sul (1)
- Massachusetts Institute of Technology (1)
- Memoria Académica - FaHCE, UNLP - Argentina (7)
- Ministerio de Cultura, Spain (7)
- Portal de Revistas Científicas Complutenses - Espanha (2)
- Publishing Network for Geoscientific & Environmental Data (57)
- QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast (3)
- Queensland University of Technology - ePrints Archive (8)
- ReCiL - Repositório Científico Lusófona - Grupo Lusófona, Portugal (1)
- Repositorio Académico de la Universidad Nacional de Costa Rica (3)
- Repositório Científico do Instituto Politécnico de Santarém - Portugal (1)
- Repositorio Institucional de la Universidad Nacional Agraria (1)
- Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho" (29)
- RIBERDIS - Repositorio IBERoamericano sobre DIScapacidad - Centro Español de Documentación sobre Discapacidad (CEDD) (5)
- RUN (Repositório da Universidade Nova de Lisboa) - FCT (Faculdade de Cienecias e Technologia), Universidade Nova de Lisboa (UNL), Portugal (1)
- School of Medicine, Washington University, United States (1)
- SerWisS - Server für Wissenschaftliche Schriften der Fachhochschule Hannover (1)
- Universidad Autónoma de Nuevo León, Mexico (4)
- Universidad de Alicante (7)
- Universidad del Rosario, Colombia (5)
- Universidad Politécnica de Madrid (4)
- Universidade Complutense de Madrid (2)
- Universidade de Lisboa - Repositório Aberto (3)
- Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP) (1)
- Universidade Federal do Rio Grande do Norte (UFRN) (1)
- Universidade Metodista de São Paulo (2)
- Universitat de Girona, Spain (2)
- Universitätsbibliothek Kassel, Universität Kassel, Germany (1)
- Université de Lausanne, Switzerland (3)
- Université de Montréal, Canada (4)
- University of Connecticut - USA (1)
- University of Michigan (220)
- University of Queensland eSpace - Australia (1)
- WestminsterResearch - UK (1)
Resumo:
In recent years, studies about the physicochemical properties of mixed oxides, call attention of the scientific community, properties like as piezoelectricity, photoluminescence, or applications as catalysts, arise in these compounds, when their chemical compositions are modified, in this context some routes are employed in the synthesis of these materials, among which can be cited these methods: ceramic, combustion, co-precipitation, Pechini or polymeric precursor method, hydrothermal, sol-gel; these routes are divided into traditional routes or chemical routes. In this work were synthesized oxides with variable composition, from the thermal decomposition of titanium, cobalt, nickel and praseodymium nitrilotriacetates. The nitrilotriacetates were characterized by IR Spectroscopy (FTIR), Thermogravimetric (TG/ DTG) and Differential Scanning Calorimetry (DSC), while oxides have been characterized by X-ray diffraction (XRD), Spectrofluorimetry and IR Spectroscopy (FTIR). From FTIR data, it was demonstrated that the displacement of the band corresponding to the carboxylate group (νCOOH) at 1712 cm-1, present in nitrilotriacetic acid (H3NTA), for 1680-1545 cm-1, these stretches are characteristics of coordinated nitrilotriacetates, By thermal analysis (TG/DTG /DSC), it was suggested, that in an oxidizing atmosphere (air) oxides are obtained at lower temperatures than in an inert atmosphere N2(g). By results from X-ray Diffraction (XRD), it was determinated that the oxides are crystalline and the predominant phases obtained are summarized titanate phases rutile and ilmenite. By fluorimetry was observed that the intensity of emission bands are directly proportional to the concentration of ions Ni2+, Co2+ and Pr3+, and IR spectroscopy (FTIR) from oxides, demonstrated the disappearance of characteristic bands by nitrilotriacetates, determining the complete decomposition of the nitrilotriacetates in oxides