• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • Tagged with
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An investigation into human biowaste management using microwave hydrothermal carbonization for sustainable sanitation

Afolabi, Oluwasola O. D. January 2015 (has links)
The prolonged challenges and dire consequences of poor sanitation, especially in developing economies, call for the exploration of new sustainable technologies. These need to be: capable of effectively treating human faecal wastes without any health or environmental impacts; scalable to address rapid increases in population and urbanization; capable of meeting environmental regulations and standards for faecal management; and competitive with existing strategies. Further and importantly, despite its noxiousness and pathogenic load, the chemical composition of human biowaste (HBW) indicates that it may be considered to be a potentially valuable, nutrient-rich renewable resource, rather than a problematic waste product. This doctoral study therefore investigated microwave hydrothermal carbonization (M-HTC) as a sanitation technology for processing HBW - to convert it into a safe, pathogen-free material, while also recovering inherent value and providing an economic base to sustain the technology. To this end, the products of M-HTC treatment of sewage sludge, human faecal sludge, synthetic faecal simulant and human faeces were characterized with a suite of techniques and tests to demonstrate pathogenic deactivation, and the intrinsic value of the resultant solid char and liquor.
2

Nanopartículas de prata e Ag/Zno nanoestruturado como agentes antimicrobianos obtidos por processo hidrotermal de micro-ondas. / Silver nanoparticles and Ag / ZnO nanostructured as antimicrobial agents obtained by hydrothermal process of microwaves.

Santana, Suelanio Viegas de 29 August 2012 (has links)
Made available in DSpace on 2015-05-14T13:21:16Z (GMT). No. of bitstreams: 1 Arquivototal.pdf: 3817465 bytes, checksum: 48db05ac5b1af395dffcbde5a5601151 (MD5) Previous issue date: 2012-08-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study consists of the acquisition, characterization and evaluation of antimicrobial silver nanoparticles and nanostructured Ag/ZnO. The silver nanoparticles were obtained through a new route using AgNO3 as precursor salt and ammonium citrate as reducing agent. Concerning the commercial zinc oxide, silver nanoparticles were impregnated using the microwave hydrothermal method at different synthesis times. Samples of Ag / ZnO nanostructured were characterized by using techniques of X-Ray Diffraction (DRX), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The colloidal silver nanoparticles obtained during the processes were characterized through optical spectroscopy in the ultraviolet and visible (UV-Vis) regions. Antimicrobial activity assays were carried for the Ag / ZnO nanostructured and for colloidal silver nanoparticles. They were included six bacteria species as well as six fungal species. Analysis of toxic and cytotoxic activity was performed for colloidal silver nanoparticles on fingerlings of Poecilia Reticulata and Artemia salina. The results show that the chosen synthesis method is effective for silver synthesis, as well as for the process of impregnation of the silver nanoparticles on the commercial zinc oxide. The biological tests revealed significant antimicrobial activity of silver nanoparticles on the micro-organisms analyzed and their low toxicity. / Este trabalho consiste na obtenção, caracterização e avaliação antimicrobiana de nanopartículas de prata e Ag/ZnO nanoestruturado. As nanopartículas de prata foram obtidas através de uma nova rota utilizando AgNO3 como sal precursor e citrato de amônio como agente redutor. Sobre óxido de zinco comercial foram impregnadas nanopartículas de prata por meio do método hidrotermal de micro-ondas em diferentes tempos de síntese. As amostras Ag/ZnO nanoestruturado foram caracterizadas através das técnicas de difração de raios X (DRX), microscopia eletrônica de varredura (MEV) e espectroscopia de energia dispersiva (EDS). As nanopartículas de prata coloidais obtidas durante os processos foram caracterizadas por meio da espectroscopia óptica na região do ultravioleta e visível (UV-Vis). Ensaios de atividade antimicrobiana foram procedidos para o Ag/ZnO nanoestruturado e para as nanopartículas de prata coloidal. Foram incluídas seis espécies bacterianas e seis espécies fúngicas. Análises da atividade tóxica e citotóxica, foram procedidas para as nanopartículas de prata coloidal sobre alevinos de Poecilia Reticulata e sobre Artemia salina. Os resultados demostram que método de síntese escolhido se mostrou eficaz para a síntese da prata, bem como no processo de impregnação das nanopartículas de prata sobre o óxido de zinco comercial. Os testes biológicos revelaram significativa atividade antimicrobiana das nanopartículas de prata sobre os micro-organismos analisados e a sua baixa toxidade.
3

Estudo das propriedades microestruturais e ópticas do BaMoO4 processado em hidrotermal assistido por microondas

Tranquilin, Ricardo Luis [UNESP] 18 September 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-09-18Bitstream added on 2014-06-13T19:50:19Z : No. of bitstreams: 1 tranquilin_rl_me_bauru.pdf: 1401003 bytes, checksum: 671b0d9181df24fb0ba937b77bcac1d8 (MD5) / O estudo das propriedades fotoluminescentes nos diferentes materiais tanto orgânicos e inorgânicos tem despertado muito o interesse da comunidade científica. Dentre os molibdatos, destacamos o molibdato de bário (BAMoO4) devido suas propriedades ópticas e termoelétricas que junto com suas emissões luminescentes no azul, verde e laranja o tornam um importante material. Neste trabalho, pós de molibdato de bário foram sintetizados pelo método de coprecipitação e processados a 140 ºC por diferentes tempos, em hidrotermal assistido por irradiação de microondas. A caracterização dos pós foi realizada através de difração de raios - X, espectroscopia Raman, absorção na região do infravermelho. As análises microestruturais e morfológicas destes pós foram realizadas através das técnicas de microscopia eletrônica de varredura por canhão de elétrons e microscopia de Transmissão. As propriedades ópticas foram verificadas por meio da espectroscopia na região do ultravioleta visível e medidas de fotoluminescência. / The study of properties in different photoluminescent both organic and inorganic materials has attracted much interest form the scientific community. Among the molybdate,. the highlight of barium molybdate (BaMoO4) because their optical properties and thermoelectric that along with its luminescent emission in blue, green and orange make it an important material. In this work of barium molybdate were synthesized by co-precipitation method and processed at 140 ºC for diferent times in hydrothermal assisted by microwave irradiation. The characterization of powders was carried out by-ray diffraction - X, Raman spectroscopy, absorption in the infrared region. The micro structural and morphological analyses of these powders were performed using the techniques of field emission gun scanning electronic microscopy and by trasmission electronic microscopy. The optical properties were observed by spectroscopy in region the ultraviolet visible and measures of photoluminescence.
4

Estudo das propriedades microestruturais e ópticas do BaMoO4 processado em hidrotermal assistido por microondas /

Tranquilin, Ricardo Luis. January 2009 (has links)
Orientador: Élson Longo / Banca: Fenelon Martinho Lima Pontes / Banca: Alberthmeiry Teixeira Figueiredo / - 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 da Unesp / Resumo: O estudo das propriedades fotoluminescentes nos diferentes materiais tanto orgânicos e inorgânicos tem despertado muito o interesse da comunidade científica. Dentre os molibdatos, destacamos o molibdato de bário (BAMoO4) devido suas propriedades ópticas e termoelétricas que junto com suas emissões luminescentes no azul, verde e laranja o tornam um importante material. Neste trabalho, pós de molibdato de bário foram sintetizados pelo método de coprecipitação e processados a 140 ºC por diferentes tempos, em hidrotermal assistido por irradiação de microondas. A caracterização dos pós foi realizada através de difração de raios - X, espectroscopia Raman, absorção na região do infravermelho. As análises microestruturais e morfológicas destes pós foram realizadas através das técnicas de microscopia eletrônica de varredura por canhão de elétrons e microscopia de Transmissão. As propriedades ópticas foram verificadas por meio da espectroscopia na região do ultravioleta visível e medidas de fotoluminescência. / Abstract: The study of properties in different photoluminescent both organic and inorganic materials has attracted much interest form the scientific community. Among the molybdate,. the highlight of barium molybdate (BaMoO4) because their optical properties and thermoelectric that along with its luminescent emission in blue, green and orange make it an important material. In this work of barium molybdate were synthesized by co-precipitation method and processed at 140 ºC for diferent times in hydrothermal assisted by microwave irradiation. The characterization of powders was carried out by-ray diffraction - X, Raman spectroscopy, absorption in the infrared region. The micro structural and morphological analyses of these powders were performed using the techniques of field emission gun scanning electronic microscopy and by trasmission electronic microscopy. The optical properties were observed by spectroscopy in region the ultraviolet visible and measures of photoluminescence. / Mestre

Page generated in 0.0642 seconds