Traditional processing technologies can negatively affect polyphenolics of blueberry products. Optimization of hydrothermodynamic (HTD) processing has been used to minimize blueberry-based product quality degradation. Preliminary experiments have shown that the quality of HTD blueberry purée in terms of anthocyanin concentration and tannin content was significantly higher than that of most commercial blueberry products. HTD technology provided pasteurization with significantly lower losses of anthocyanins as compared with conventional heating. Screening of the factors has shown that holding time, temperature of pasteurization and heating rate were significant, while cavitation mode was non-significant. Response surface methodology was used to determine an optimal combination of temperature and time (92 to 95°C with holding time 0.5 to 2.0 min). Non-linear regression analysis of the shelf-life data has provided fitted models which could be used to predict changes in anthocyanin concentration and tannins for different storage periods at 4°C and at room temperature (20 to 25°C).

The main objective of this research was to develop a catalytic thermal conversion process for production of carbon-based nanomaterials (CNs) from kraft lignin. Four specific objectives were to: (1) understand the structural evolution of kraft lignin during its thermal treatment process; (2) investigate effects of temperature, and iron catalyst loading and morphology on the catalytic thermal conversion of kraft lignin to CNs, understand lignin catalytic thermal conversion mechanism; (3) explore potential applications of CNs synthesized from kraft lignin as an adsorbent for lead removing from contaminated water; (4) and propose effective methods for graphene material characterization. Experimental results indicated that the crystallinity of CNs from non-catalytic thermal conversion of kraft lignin increased and amorphous potion in CNs decreased with increased temperature. Specifically, as temperature increased from 500 to 1000 °C, CNs had its lateral crystallite size (La) increased from 6.97 to 13.96 angstrom, its lattice space (d002) decreased from 3.56 to 3.49 angstrom, and its crystallite (Lc) thickness was between 8 to 9 angstrom. The process of catalytic thermal conversion of kraft lignin yielded graphene-based nanomaterials such as multilayer graphene-encapsulated iron nanoparticles (MLGEINs), multilayer graphene (MLG) sheets, and MLG nanoribbons. Producing MLGEINs required a minimum temperature of 750 °C. The minimum temperature for producing MLG sheets and MLG nanoribbons was found to be 600 °C. It was found that carbonous gases from kraft lignin decomposition acted as the carbon source for MLG sheets and MLG nanoribbons formation, and solid carbon from carbonized lignin acted as the carbon source for the formation of MLGEINs. The yield of CNs increased with increased iron loading. Solid iron nanoparticles as a catalyst favor to form MLG nanoribbons, while iron nitrate favors to form MLGEINs. MLGEINs showed a good sorption capacity for aqueous Pb2+. The adsorption mechanism was mainly dominated by ion-exchange reaction. The final lead contains MLGEINs can be rapidly separated from solution through a magnet. FTIR, Raman, and HRTEM techniques are effective tools for characterizing defects in graphene-based materials. XRD technique is useful to evaluate the average structure parameters of graphene-based materials. SEM technique can be used to characterize morphology of graphene-based materials.

This research aimed to unite virtues of intrinsically microporous polyimides (PIM-PIs) and thermally treated polymers to develop advanced high-performance membranes with not only high permeability and high selectivity, but mechanical resilience, thermal and chemical stability, and plasticization resistance. Recent research showed that thermal treatment of polymers below or above their degradation temperatures is a potential avenue for improving gas transport properties. Thermally rearranged (TR), thermally crosslinked, or carbon molecular sieve (CMS) membranes have demonstrated promising results in addressing some pressing challenges of gas separation membranes such as chemical stability and plasticization resistance. However, the thermal treatment of PIM-PIs is scarcely studied, and its effect on gas transport properties still remains vague. This Ph.D. work started by investigating the solid-state conversion of PIM-PIs into heterocyclic ring systems upon heat treatment. The PIM-PIs containing functional hydroxyl- and cyano-groups were thermally treated to derive two types of cyclisation systems – conventional polybenzoxazole (PBO) and novel isoindoloquinazolinedione (IQD). Compared to the PIM-PI derived PBO, the novel solid-state conversion of intrinsically microporous cyanoimides into IQD favorably enhanced ultramicropores with up to 80% increase in gas permeability without an expense of gas-pair selectivity. Furthermore, by studying the thermal treatment of non-functionalized and functionalized 6FDA-based polymers a long-neglected contribution of fluorine to the formation of micropores was revealed. It was concluded that the heat treatment induced a continuous fluorine release at 450 °C – crosslinking polymer chains and increasing free volume accessible for gas transport. Finally, for the first time, a hydroxyl-functionalized PIM-PI, 6FDA-HTB, was heat treated by stepwise temperature increase from below, to near and above its degradation temperature to form TR, intermediate and early-stage CMS membranes. This study provided valuable insights on the correlation between the ultra- and micropore development and gas transport properties in PIM-PIs as a function of treatment temperature. Compared to the precursor, the intermediate stage membranes possessed 20-30 times higher CO2 permeability with equivalent CO2/CH4 selectivity. Also, intermediate and early-stage carbon derivatives of 6FDA-HTB exhibited an outstanding 1:1 CO2/CH4 mixed-gas separation results well transcending the 2018 mixed-gas upper bound line. These results deemed further investigation of intermediate stage membranes attractive.

Perfluorosulfonate ionomer (PFSI) membranes were annealed at elevated temperature for various periods of time in order to investigate the morphological effects of thermal treatments. For Nafion® 117, the DSC thermograms of Na+-, Cs+- and tetramethylammonium(TMA+)-form membranes show an endothermic peak develops upon annealing at 200ºC, indicating the development of crystallinity in the membrane. For these three samples annealed under same conditions, the heat of fusion (ΠH) values of the endothermic event increases with increasing counterion size. Larger tetraalkylammonium ions, tetraethylammonium(TEA+) and tetrapropylammonium(TPA+), result in no significant peak upon annealing at 200ºC. DSC thermograms of annealed Na+-form 3M Ionomer show no peak upon annealing and DSC thermograms of annealed TMA+-form 3M Ionomer show a very small peak that develops with annealing time at high equivalent weights. Annealed TMA+-form Dow Ionomer, which has a side chain shorter than both Nafion® and 3M Ionomer and a smaller mole% of side chains at the same equivalent weight, shows a relatively high ΠH value, which might also be related to its blocky nature. These results show that the isothermal crystallization kinetics of PFSI is affected by the counterion attached to the sulfonate group, the length of side chain, the mole% of side chains and the nature of the membrane. Water uptake analysis has been performed on annealed membranes, and the result shows that water uptake decreases with increasing degree of crystallinity. / Master of Science

O objetivo deste trabalho visa analisar criticamente o processo de fabricação do arame galvanizado, discutindo a influência de variáveis, tais como: composição química do aço, velocidade dos fios na linha de galvanização e temperaturas associadas ao tratamento térmico, garantindo com isto um produto aderente as novas necessidades apresentadas pelo setor da avicultura que emprega o arame galvanizado BWG 18 na confecção de telas. A metodologia adotada envolveu as etapas de revisão da literatura e procedimento experimental D.O.E. (Design of Experiments), com coleta de amostras sob diferentes empregos (matéria prima) e condições operacionais (alteração de velocidades na linha de galvanização) e posterior realização de ensaios e análises de laboratório nas amostras coletas. Na etapa final foi realizado a avaliação e discussão dos resultados obtidos, identificando o produto galvanizado que melhor atende as propriedades mecânicas exigidas na fabricação de telas para o setor de avicultura. / The objective of this work aims at critically analyze the process of manufacture of the galvanized wire, arguing the influence of variables, such as: chemical composition of the steel, wire speed in the galvanizing line and temperatures associates to the heat treatment, ensuring with this an adherent product the new necessities presented for the poultry keeping that uses galvanized wire BWG 18 in the manufacturing of wire mesh. The adopted methodology involved the stages of revision of literature and experimental procedure D.O.E. (Design of Experiments), with acquisition of samples under different jobs (raw material) and operational conditions (alteration of speeds in the galvanizing line) and later accomplishment of assays and analyses of laboratory in the samples collections. In the final stage it was carried through the evaluation and quarrel of the acquired results, identifying the galvanized product that better takes care of the demanded mechanical properties in the manufacture of wire mesh for the poultry keeping sector.

In this study, the reactive rf magnetron sputtering was used to deposit zinc oxide (ZnO) thin films on Si substrate. The optimal sputtering parameters for film as luminescence application were found to be oxygen concentration (O2/O2+Ar) of 21%, RF power of 100W, substrate temperature of 500¢XC and sputtering pressure of 5 mtorr. Beside, the thermal treatment procedure was carried out to improve the luminescence characteristics of ZnO thin films. The physical characteristics of ZnO thin films deposited on Si substrate with different sputtering parameters were obtained by the analyses of XRD and SEM. The optical properties of ZnO thin films were discussed also. Ultraviolet (UV) visible spectrometer and photoluminescence spectrometer were used to measure the visible transmission and photoluminescence characteristics (PL), respectively. According to the experimental results, it is found that under optimal sputtering parameters, the emitted UV light intensity will be increased as the FWHM in x-ray diffraction is decreased, i.e. the grain size is larger. In addition, after post-deposition annealing at 800¢J, the strongest UV emission intensity was obtained in the nitrogen ambient and the strongest visible (green) emission intensity was obtained in the oxygen ambient.

Made available in DSpace on 2014-06-11T19:27:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-25Bitstream added on 2014-06-13T19:14:25Z : No. of bitstreams: 1 kimaid_mie_me_guara.pdf: 2034242 bytes, checksum: 7b11e5da6457c5a1b1399620f3fff905 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho foi avaliar a capacidade de formação da apatita na superfície da liga Ti-30TA após modificação da superfície usando o método biomimético com tipos de solução SBF diferentes, convencionais e condensado (5xSBF). A liga Ti-30TA foi obtida a partir do titânio C.P. titânio e tântalo usando um forno de arco voltaico. Os lingotes foram submetidos a um tratamento térmico e foram forjados à frio. O tarugo foi usinado em um torno CNC para atingir microestrutura e morfologia semelhante aos implantes dentários. Foram cortados discos com 13 mm de diâmetro e 3 mm de espessura. Para o tratamento de superfície, as amostras foram imersas em solução aquosa de NaOH 0,5M a 60 º C por 24 horas, lavados com água destilada e seco a 40 º C por 24h. Após o tratamento alcalino, as amostras foram tratadas termicamente a 300 º C por 1 h em um forno elétrico no ar. Os discos foram imersos em SBF para formar uma camada de apatita sobre sua superfície. As superfícies foram avaliadas por microscopia eletrônica de varredura (MEV) e microscopia de força atômica (AFM). Medidas de ângulo de contato foram realizadas a fim de avaliar a molhabilidade. Os resultados indicam a formação de um revestimento de nanoapatita sobre a superfície da liga experimental Ti-30Ta. / The purpose of this work was to evaluate apatite forming ability in surface of Ti- 30Ta alloy after modification surface using biomimetic method with different SBFs, conventional and condensed (5xSBF). Ti-30Ta alloy was obtained from C.P. titanium and tantalum by using an arc-melting furnace. Ingots were submitted to heat treatment and they were cold worked by swaging. Billet turning on a CNC lathe in order to achieve microstructure and morphology similar to dental implants. Discs with 13 mm in diameter and 3 mm in thickness were cutting. For surface treatment, samples were immersed in 0.5M NaOH aqueous solution at 60ºC for 24 hours, washed with distilled water and dried at 40ºC for 24h. After the alkaline treatment, samples were heat treated at 300 ºC for 2 h in an electrical furnace in air. Discs were soaking in SBF to form an apatite layer on the surface. Surfaces were investigated using scanning electron microscope (SEM) and atomic force microscopy (AFM). Contact angle measurements were carried out in order to evaluate the wettability. The results indicate that nanoapatite coating could form on surface of Ti- 30Ta experimental alloy.

Approximately 96,000 tonnes of the UK Higher Activity Waste (HAW) inventory consists of irradiated nuclear graphite. The current Nuclear Decommissioning Authority (NDA) baseline strategy for irradiated graphite in England and Wales is isolation in a future Geological Disposal Facility, with Scottish policy endorsing an alternative decision of near surface long-term storage. Irradiated graphite disposal routes in the UK remain under review, however, as there are concerns surrounding timing and whether deep geological disposal is the most appropriate course of action for graphite. An alternative waste management solution is treatment prior to disposal to separate mobile radioactive isotopes such as 3H and 14C from the bulk material, allowing for HAW volume reduction and concentration. Optimisation of an existing thermal treatment process at the Nuclear Graphite Research Group (NGRG) of the University of Manchester has been effected and a detailed review of the uncertainties associated with quantitative determination of radioisotope releases during thermal treatment of irradiated graphite samples has been conducted. Thermal treatment experiments in both an inert atmosphere and 1% oxygen in argon atmosphere have been conducted for temperatures ranging from 600°C to 800°C, and durations from 4 to 120 hours, to determine the effects of oxidation time and temperature, and the consequent oxidation characteristics on the release rate of prominent radioisotopes, with a focus on the release of 14C. Lower temperature treatments in an oxidising atmosphere have shown that a preferential release of 14C-enriched graphite can be achieved from the bulk material of Oldbury Magnox reactor irradiated graphite, with evidence demonstrating that this liberated 14C-enriched region is located at the graphite surfaces throughout the porous structure. A large proportion of radiocarbon found in this irradiated graphite, however, is uniformly distributed throughout the bulk material and cannot be selectively oxidised. It is found that prominent metallic radioisotopes such as 60Co are not mobile at these temperatures and remain in the bulk graphite material, inclusive of radioactive caesium which the literature suggests will volatilise. The preliminary results were undertaken as part of the EU FP7 EURATOM Project: CARBOWASTE.

O objetivo deste trabalho visa analisar criticamente o processo de fabricação do arame galvanizado, discutindo a influência de variáveis, tais como: composição química do aço, velocidade dos fios na linha de galvanização e temperaturas associadas ao tratamento térmico, garantindo com isto um produto aderente as novas necessidades apresentadas pelo setor da avicultura que emprega o arame galvanizado BWG 18 na confecção de telas. A metodologia adotada envolveu as etapas de revisão da literatura e procedimento experimental D.O.E. (Design of Experiments), com coleta de amostras sob diferentes empregos (matéria prima) e condições operacionais (alteração de velocidades na linha de galvanização) e posterior realização de ensaios e análises de laboratório nas amostras coletas. Na etapa final foi realizado a avaliação e discussão dos resultados obtidos, identificando o produto galvanizado que melhor atende as propriedades mecânicas exigidas na fabricação de telas para o setor de avicultura. / The objective of this work aims at critically analyze the process of manufacture of the galvanized wire, arguing the influence of variables, such as: chemical composition of the steel, wire speed in the galvanizing line and temperatures associates to the heat treatment, ensuring with this an adherent product the new necessities presented for the poultry keeping that uses galvanized wire BWG 18 in the manufacturing of wire mesh. The adopted methodology involved the stages of revision of literature and experimental procedure D.O.E. (Design of Experiments), with acquisition of samples under different jobs (raw material) and operational conditions (alteration of speeds in the galvanizing line) and later accomplishment of assays and analyses of laboratory in the samples collections. In the final stage it was carried through the evaluation and quarrel of the acquired results, identifying the galvanized product that better takes care of the demanded mechanical properties in the manufacture of wire mesh for the poultry keeping sector.

O objetivo deste trabalho visa analisar criticamente o processo de fabricação do arame galvanizado, discutindo a influência de variáveis, tais como: composição química do aço, velocidade dos fios na linha de galvanização e temperaturas associadas ao tratamento térmico, garantindo com isto um produto aderente as novas necessidades apresentadas pelo setor da avicultura que emprega o arame galvanizado BWG 18 na confecção de telas. A metodologia adotada envolveu as etapas de revisão da literatura e procedimento experimental D.O.E. (Design of Experiments), com coleta de amostras sob diferentes empregos (matéria prima) e condições operacionais (alteração de velocidades na linha de galvanização) e posterior realização de ensaios e análises de laboratório nas amostras coletas. Na etapa final foi realizado a avaliação e discussão dos resultados obtidos, identificando o produto galvanizado que melhor atende as propriedades mecânicas exigidas na fabricação de telas para o setor de avicultura. / The objective of this work aims at critically analyze the process of manufacture of the galvanized wire, arguing the influence of variables, such as: chemical composition of the steel, wire speed in the galvanizing line and temperatures associates to the heat treatment, ensuring with this an adherent product the new necessities presented for the poultry keeping that uses galvanized wire BWG 18 in the manufacturing of wire mesh. The adopted methodology involved the stages of revision of literature and experimental procedure D.O.E. (Design of Experiments), with acquisition of samples under different jobs (raw material) and operational conditions (alteration of speeds in the galvanizing line) and later accomplishment of assays and analyses of laboratory in the samples collections. In the final stage it was carried through the evaluation and quarrel of the acquired results, identifying the galvanized product that better takes care of the demanded mechanical properties in the manufacture of wire mesh for the poultry keeping sector.