Avaliação do desempenho de aços inoxidáveis ferríticos com relação a propriedades mecânicas e oxidação em altas temperaturas

Orientador: Haroldo de Araújo PonteDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduaçao em Engenharia - PIPE. Defesa: Curitiba, 15/12/2008Inclui bibliografiaÁrea de concentraçao: Engenharia e ciencias de materiai

Photocatalytic performance of textiles coated with titanium dioxide-reduced graphene oxide system for degradation of crude petroleum under similar solar irradiation

The pollution caused by oil and its toxic derivatives presents a considerable risk to the public health and the environment. This work is devoted to the study of the influence of TiO2 nanoparticles immobilized on three types of textiles materials (Cotton, Entretela, and Polylactic Acid-PLA) coated with reduced graphene oxide (RGO) to be used for degradation of crude petroleum under simulated solar irradiation. The morphological studies of the functionalized textiles substrates were performed by using Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy, which indicated an excellent dispersion and adhesion of nanoparticles of about 60% (atomic %Ti) on the textile fibers covered with RGO after washing. Ultraviolet-visible Diffuse Reflectance spectra suggest a reduction in the band gap energy of TiO2 up to 2.86 eV due to the presence of RGO. The functionalized textiles presented at least 60% of photocatalytic efficiency measured by Rhodamine B degradation, decreasing less than 12% after the rigorous washing. The excitation/emission Synchronous Fluorescence Spectroscopy and Fourier-transform Infrared spectroscopies demonstrated a great potential for photocatalytic degradation of the functionalized textiles substrates as the appearance of the hydroxyl, carboxyl, and the C-O bands confirm the photoinduced oxidation of the organic compounds implying with high prospects in petroleum and wastewater treatment areas. Moreover, this environmentally friendly, sustainable, and inclusive research work can be included in clean technologies, contributing to the novel socio-economic model recognized as "Green Recovery".[GRAPHICS].This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2019 and the project PTDC/FIS-MAC/6606/2020. Also, the third author would like to acknowledge the FCT for the Ph.D. scholarship (SFRH/BD/137421/2018). Moreover, the authors would like to acknowledge Sociedade Nacional de Combusti ' veis de Angola (Sonangol), which partially provided the crude oil samples

Avaliação do desempenho de aços inoxidáveis ferríticos com relação a propriedades mecânicas e oxidação em altas temperaturas

Orientador: Haroldo de Araújo PonteDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduaçao em Engenharia - PIPE. Defesa: Curitiba, 15/12/2008Inclui bibliografiaÁrea de concentraçao: Engenharia e ciencias de materiai

New Trends for Controlled-Release of TBH Herbicide in the Field by Using a Biodegradable Polymer Fashion

The herbicide Tebuthiuron (TBH) is widely used to weed control in sugar cane and cotton crops. However, TBH when applied to the soil is prone to the leaching process due to its high solubility, reaching soil layers below the required control zone. Here, we present a new insight for controlled-release of TBH herbicide by using a microparticulate system on the weed plants of difficult control. For this purpose, calcium alginate (Ca-ALG) microparticles containing the TBH herbicide were developed as a strategy to reduce the groundwater contamination, caused by the mobility of the herbicide element. The obtained results are innovative since demonstrates potential application in controlled-release as well as efficiency on the weed species control of Digitaria horizontalis (Willd) and Ipomoea grandifolia (Dammer) O'Donell weed species in pre-emergence. DOI: http://dx.doi.org/10.17807/orbital.v12i4.1552<br /