Orientador: Rodrigo Ramos Catharino / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T18:57:06Z (GMT). No. of bitstreams: 1 Guerreiro_TatianeMelina_M.pdf: 2016380 bytes, checksum: ef19a1e7b43ddd65fdb309939a8ceaf1 (MD5) Previous issue date: 2015 / Resumo: O Vinagre Balsâmico é um produto italiano de grande valor, bastante apreciado em todo o mundo devido ao seu sabor característico e aos seus potenciais benefícios à saúde. Ao longo dos últimos anos, diversos pesquisadores realizaram estudos que avaliaram a sua composição físico-química, microbiana e suas propriedades benéficas. Devido ao alto número de estudos que confirmam o seu caráter antioxidante e suas propriedades anti-hipertensivas e antiglicêmicas, o vinagre balsâmico é um produto alvo de fraudes e adulterações. Desta forma, há uma preocupação acerca dos balsâmicos autênticos, que possuam certificação tanto para sua origem (região ou país), como para suas condições de processamento, garantindo sua qualidade e originalidade. Por isso, o esforço para a redução de fraudes, bem como a garantia da qualidade dos balsâmicos são de grande interesse tanto para saúde do consumidor, quanto do ponto de vista econômico. Buscando encontrar estratégias analíticas confiáveis, capazes de avaliar rapidamente a qualidade do vinagre balsâmico, este trabalho emprega a técnica de Espectrometria de Massas por Ionização/Dessorção a Laser em Placa de Sílica (SP-LDI-MS) para a rápida caracterização química de amostras de vinagres balsâmicos comercial e com indicação geográfica protegida (IGP), e identificação de suas amostras adulteradas com vinagres de baixo custo, provenientes de maçã, álcool e vinhos branco e tinto / Abstract: The Balsamic Vinegar is a valuable Italian product, very popular worldwide due to its distinctive flavor and potential health benefits. Several studies have been conducted to assess physicochemical and microbial compositions as well as with respect to its beneficial properties. Due to the high number of studies that confirm its antioxidant character and their antihypertensive and antiglycemic properties, balsamic vinegar is a potential target for frauds and adulterations. Thus, there is growing concern about the search for authenticated balsamics, so make sure your origin (region or country) as well as their processing conditions, which guarantee quality and originality of balsamic vinegar. Striving for fraud reduction and ensuring the quality and safety of food through reliable analytical strategies to quickly assess the quality of balsamic vinegar are of great interest to health and the economic point of view. In this context, this work employs the technique of Silica Plate Laser Desorption/Ionization Mass Spectrometry (SP-LDI-MS) for rapid chemical characterization of samples of commercial balsamic vinegars and with protected geographical indications (PGI) and identification their samples adulterated with inexpensive vinegars from apple, alcohol and red and white wines / Mestrado / Fisiopatologia Médica / Mestra em Ciências

Orientador: Luís Roberto Marcondes Martins / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T03:21:27Z (GMT). No. of bitstreams: 1 Santos-Caldeira_MilenaMariaPierre_D.pdf: 2166037 bytes, checksum: 223155da07d2c223b86bb075bcb388de (MD5) Previous issue date: 2015 / Resumo: Dentro da abordagem minimamente invasiva da doença cárie, um material resinoso a base de metacrilatos, denominado infiltrante Icon® (DMG), foi apresentado com objetivo de paralisar lesões cariosas incipientes em esmalte pela penetração e polimerização dentro das mesmas. Para análise deste material, os objetivos do presente estudo foram: 1) avaliar a influência do pré-aquecimento (AQ) nas propriedades grau de conversão (GC), resistência à flexão (RF), módulo de elasticidade (ME), dureza Knoop (KN) e redução percentual de dureza (RD) de Icon®; e, 2) avaliar a influência do envelhecimento (EN) nas propriedades rugosidade superficial (RS), KN, RF e ME de Icon®. Para avaliação do efeito de AQ (n=10), corpos de prova foram confeccionados (7x2x1mm) de acordo com os grupos divididos em: G1, Icon sem aquecimento; G2, Icon pré aquecido em estufa a 37oC por 1h; G3, Icon com aplicação de ar frio (23oC) por 20 s; G4, Icon com aplicação de ar quente (40oC) por 20 s. GC foi avaliado através da Espectroscopia por Infravermelho Transformada de Fourier (FTIR). RF e ME foram obtidos pelo teste de resistência à flexão de 3 pontos, em máquina de ensaio universal a 0,5mm/min. KN foi avaliada pela média de 3 indentações sob carga de 50g por 15s, e, RD foi avaliada por KN após imersão dos corpos de prova em etanol por 24h. Os dados para avaliação de AQ foram submetidos a ANOVA um critério (5%). Para avaliação de EN (n=20), amostras do infiltrante foram confeccionadas (7x2x1mm) e armazenadas em saliva artificial, a 37oC, até o momento das análises. O fator tempo foi avaliado, nos mesmos espécimes, em 3 níveis (24h, 6 meses e 12 meses) para RS e KN; porém, para RF e ME, tempo foi avaliado em 2 fases (24h e 12 meses) em espécimes distintos devido ao teste destrutivo utilizado. RS foi avaliada, em 24h, 6 e 12 meses, pela média de 3 leituras Ra em rugosímetro. KN foi avaliada em 24h, 6 e 12 meses como previamente descritos para AQ. Enquanto, RF e ME foram avaliados em 24h e 12 meses como também descrito para AQ. Os dados de RS e KN foram submetidos à análise de medidas repetidas e teste de Tukey, enquanto que os dados de RF e ME foram submetidos a ANOVA um critério (5%). O aumento da temperatura do material Icon, não mostrou nenhuma melhora em relação a GC, RF, ME, KN e RD pelos diferentes métodos de preparo testados. Após envelhecimento, RS aumentou significativamente da análise comparado a 6 e 12 meses, enquanto KN sofreu redução nos mesmos 3 tempos testados, havendo correlação inversamente proporcional entre estas propriedades de Icon®. Adicionalmente, houve redução significante de RF e ME após envelhecimento de Icon®. Desta forma, pode-se concluir que o aquecimento do material não interferiu nas propriedades testadas, e o envelhecimento deteriorou as propriedades do infiltrante / Abstract: Within the minimally invasive approach to caries, a methacrylates based material, Icon® infiltrant (DMG), was presented in order to paralyze incipient enamel carious lesions by penetration and polymerization inside caries lesions. For material analysis, the aims of this study were: 1) to evaluate the effect of pre heating material (HE) in conversion degree (CD), flexural strength (FL), elastic modulus (EM), Knoop hardness (KN) and softening ratio (SR); and, 2) to evaluate the effect of artificial aging (AG) in surface roughness (SU), KN, FL and EM. For HE evaluation (n = 10), 10 specimens were prepared (7x2x1mm) according to the groups that were set up as follows: G1, unheated Icon; G2, preheated Icon in oven at 37°C for 1h; G3, Icon with cold air application (23°C) for 20s; G4 Icon with heated air application (40°C) for 20s. CD was measured by Fourier Transform Infrared spectroscopy (FTIR). FL and EM were evaluated by three-point bending test using an universal testing machine by 0,5mm/min. KN was assessed by three indentations average on load of 50g for 15s. And crosslink density was indirectly assessed by hardness softening ratio after ethanol immersion for 24h. The HE evaluation data were submitted to one-way ANOVA (5%). For AG evaluation (n = 20), samples were prepared (7x2x1mm) and stored in artificial saliva at 37°C until the analysis time. The time factor was evaluated in the same specimens, on 3 levels (24h, 6 months and 12 months) for SU and KN; however, for FL and EM, the time was evaluated in 2 levels (24h and 12 months) at different specimens because of the destructive testing. SU was evaluated at 24h, 6 and 12 months, by 3 readings roughness average (Ra cut-off). KN was assessed at 24h, 6 and 12 months, as previously described for AQ. FL and EM were evaluated at 24h and 12 months as well as described for AQ. Data from SU and KN were submitted to repeated measures analysis and Tukey test, while FL and EM data were submitted to one-way ANOVA (5%). Hight temperature did not improved CD, FL, EM, KN and SR by different prepare methods tested. Aging significantly increased SU from the initial analysis compared to 6 and 12 months, while KN decreased in the same three times tested, with inverse correlation between the properties. There was a significant FL and EM reduction after material aging. Therefore, it can be concluded that heating did not affect material properties tested, however, aging deteriorated infiltrant properties / Doutorado / Dentística / Doutora em Clínica Odontológica

Thesis (M.Sc.(Soil Science)) -- University of Limpopo, 2015 / Winery solid waste materials namely, wine filter materials (FM), grape marc (berry stalks, skins and seeds) and chopped grapevine pruning canes were composted in heaps through a thermophilic process. The filter materials were mixed with the grape marc and grapevine prunings at five rates (10%, 25%, 50%, 75% and 100%) to produce five composts herein designated as C10FM, C25FM, C50FM, C75FM and C100FM, respectively. A laboratory incubation study was thereafter carried out to determine the nutrient release potential of the composts using two soil types with varying textural characteristics. Each compost was mixed with soil at a rate equivalent to 200 kg N ha-1 and the mineral N, available P and exchangeable K content determined over 42 days incubation period. Results revealed that the composts possess high C content and low C:N ratios; and released significantly higher NH4-N and K concentration relative to un-amended control. The differences in the amount of P mineralised among the five compost treatments were not significant while significantly higher amount of K was mineralised at higher FM mix rates. The composts were applied to maize cv. SNK2147 on sandy soil in a greenhouse pot study at five rates (5, 10, 20, 40 and 80 t ha-1) to determine their effects on crop growth and yield as well as on selected soil chemical properties. An un-fertilised control and NPK fertiliser treatments were included for comparison. The pots were arranged in a completely randomized design, with each treatment replicated four times. The C50FM, C75FM and C100FM treatments applied at 80 t ha-1 gave significantly higher maize dry matter yield than the NPK fertiliser treatment. Quantitative estimates of the optimum compost rate for dry matter production ranged from 450 to 1842 g pot-1. Application of these composts significantly increased dry matter yield, plant height, stem diameter and the number of functional leaves per plant compared to the un-fertilised control. The K content of shoot from composts treatments exceeded the critical nutritional level of 3.3%. Plant tissue Zn content from C10FM, C25FM and C50FM treatments exceeded the critical nutritional level of 15 mg kg-1 while the residual soil K, Na and Zn contents after crop harvest were significantly increased following compost application. Similarly, the residual P was significantly increased in C25FM, C75FM and C100FM treatments after harvest. In conclusion, application of these composts exerted beneficial effects on maize performance and soil. Field studies under variable conditions are recommended to validate these findings. Keywords: wine, compost, nutrient release potential, maize, soil chemical properties

In vielen technischen Anwendungen werden Faserverbundwerkstoffe mit Hochleistungsfasern aus Carbon und AR-Glas eingesetzt, die aufgrund ihrer physikalischen und chemischen Eigenschaften ein hohes Festigkeitspotential aufweisen. Damit eröffnen sich neue Anwendungsgebiete, z. B. als textile Bewehrungen für Betonbauteile. Die Garnmaterialien müssen hohe sicherheitstechnische Anforderungen erfüllen. Dazu gehören u. a. eine ausreichende Tragfähigkeit unter Dauerlastbeanspruchung und eine hohe Temperaturbeständigkeit im Brandfall. Zur Spezifizierung dieser Eigenschaften wurden experimentelle Untersuchungen durchgeführt, deren Ergebnisse nachfolgend vorgestellt werden. / Due to their strong mechanical and chemical properties, fiber composite materials composed of high performance carbon and AR-glass fibers lend themselves to many technical applications. Potentially new and innovative application fields should be considered, such as textile reinforcements for concrete components. The yarn materials must meet high technical and safety standards, specifically sufficient load-bearing capabilities under long-term conditions and acceptable strength at high temperatures should fire occur. Research was conducted to document these characteristics. The results are presented in this paper.

Orientador: Mário Tanomaru Filho / Abstract: Tricalcium silicate cements associated with radiopacifiers are used as repair materials. Publication 1: Evaluation of tricalcium silicate-based cements (TCS) associated with zirconium oxide (ZrO2), calcium tungstate (CaWO4) or niobium oxide (Nb2O5) radiopacifiers compared to MTA Repair HP (MTA HP). Publication 2: Evaluation of tricalcium silicate-based cements (TCS) associated with zirconium oxide (ZrO2) radiopacifier with 10% or 20% of Biosilicate (TCS ZrO2 + 10% Biosilicate and TCS ZrO2 + 20% Biosilicate) compared to Biodentine. Setting Time (ST) and radiopacity were evaluated based on ISO 6876/2002 standard. Solubility was evaluated according to the method proposed by Carvalho-Júnior et al. (2007) modified. pH was measured at 3, 12 and 24 hours and 7, 14 and 21 days after immersion in distilled water. Cellular cytotoxicity and bioactivity were evaluated by methyltetrazolium (MTT), neutral red (NR), alkaline phosphatase (ALP), alizarin red (ARS) and real time PCR (qPCR) (Publication 1) assays in different periods of contact with eluates of the materials in Saos-2 cells. Antibacterial activity was evaluated by direct contact on Enterococcus faecalis in the planktonic form. For the physico-chemical and ARS tests, the data were submitted to ANOVA and Tukey tests; for MTT, NR and ALP tests the data were analyzed by the Two-Way ANOVA and Bonferroni tests; the antibacterial activity, were submitted to Kruskall-Wallis and Dunn tests (α = 0.05). Publication 1: TCS + CaWO4 presented... (Complete abstract click electronic access below) / Resumo: Cimentos de silicato tricálcico com radiopacificadores são utilizados como materiais reparadores. Publicação 1: Avaliação de cimento à base de silicato tricálcico (STC) associado aos radiopacificadores óxido de zircônio (ZrO2), tungstato de cálcio (CaWO4) ou óxido de nióbio (Nb2O5) em comparação ao MTA Repair HP (MTA HP). Publicação 2: Avaliação de material à base de silicato tricálcico (STC) e radiopacificador óxido de zircônio (ZrO2) e 10% ou 20% de Biosilicato (STC ZrO2 + 10% de Biosilicato e STC ZrO2 + 20% de Biosilicato) em comparação ao Biodentine. Tempo de presa e a radiopacidade foram avaliados seguindo ISO 6876/2002. A solubilidade foi avaliada de acordo com o método proposto por Carvalho-Júnior et al. (2007) modificado. pH foi avaliado 3, 12 e 24 horas, 7, 14 e 21 dias após imersão em água destilada. A citotoxidade e bioatividade celular foram avaliadas pelos testes metiltetrazólio (MTT), vermelho neutro (VN), atividade de fosfatase alcalina (ALP), ensaio de vermelho de alizarina (ARS) e PCR em tempo real (qPCR) (Publicação1), em diferentes períodos de contato com eluídos dos materiais em células Saos-2. Atividade antimicrobiana dos materiais foi avaliada por meio do teste de contato direto com Enterococcus faecalis na forma planctônica. Para os testes físicoquímicos e ARS, os dados foram submetidos aos testes ANOVA e Tukey; para os ensaios do MTT, VN e ALP e qPCR os dados foram analisados aos testes Two Way ANOVA e Bonferroni; os dados da atividade antimicrobiana f... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Thesis (M. Sc. (Geology)) -- University of Limpopo, 2021 / Mining activities for mineral resources over the years have, according to certain people, resulted in soil damage in the Atok area because of huge amounts of waste earth and rock that was brought to the surface, this waste often becomes toxic when it comes into contact with air and water. However, the geology of the area which is mafic in composition has caused major damage to the soil in the area as well. Due the removal process of desired mineral materials, soil textures have been destroyed, various nutrient cycles disturbed, and microbial communities altered, changing the vegetation and leading to the format of land in the area. Therefore, soil restoration of mining lands became a very important part of sustainable development strategies and also prescribed by law in South Africa. The geochemistry and mineralogy of soil samples taken from the area of Atok were studied using X-Ray Fluorescence (XRF) and physio-chemical parameter analysis. These methods are used for investigating the element and mineral associations and the distribution of heavy metals in these soils around the mine. The chemical and mineralogical data from soil and tailings were collected from each of the following areas around Atok: (Sefateng, Moonametsi, Mohlahlaneng, Sefateng Tailing Dam and Mafeo), the samples were collected at various depths; at each sampling points. The results of XRF analysis indicated that the soils are rich in MgO, CaO and Fe2O3 with minerals such as pyroxenes, plagioclase feldspar and occasional olivine being dominant. An excess of these minerals caused the soil to be infertile. The physio-chemical analysis showed that the soil texture is sandy, therefore this is the reason that the soil has low water holding capacity (27%) and low soil moisture (1.2%), the pH (8.50) and EC (<0.50 dS/m). Keywords: Soil composition, chemical properties, heavy metal, contamination.

Thesis (Ph.D. (Physics)) -- University of Limpopo, 2021 / Titanium dioxide is among the most abundant materials and it has many of interesting physical and chemical properties (i.e., low density, high thermal and mechanical strength, insensitivity to corrosion) that make it a compound of choice for electrodes materials in energy storage. There are, however, limitations on the theoretical side to using the main electronic structure theories such as Hartree-Fock (HF) or densityfunctional (DFT) especially for large periodic and molecular systems. The aim of the theses is to develop a new, widely transferable, self-consistent density functional tight binding SCC-DFTB data base of TiO2, which could be applied in energy storage anodes with a large number of atoms. The TiO2, LiTiO2 and NaTiO2 potentials were derived following the SCC-DFTB parameterization procedure; where the generalized gradient approximation (GGA) and local density approximation (LDA) exchange-correlation functional were employed yielding Slater-Koster DFTB parameters. The results of derived parameters were validated by being compared with those of the bulk rutile and brookite polymorphs. The structural lattice parameters and electronic properties, such as the bandgaps were well reproduced. Most mechanical properties were close to those in literature, except mainly for C33 which tended to be underestimated due to the choice of exchange-correlation functional. The variation of the bulk lattice parameter and volume with lithiation and sodiation were predicted and compared reasonably with those in literature. The newly derived DFTB parameters were further used to calculate bulk properties of the anatase, which is chemically more stable than other polymorphs. Generally, the accuracy of the lattice structural, electronic and mechanical properties of the bulk anantase were consistent with those of the rutile and brookite polymorphs. Furthermore, nanostructures consisting of a large number of atoms, which extend beyond the normal scope of the conventional DFT calculations, were modelled both structurally and electronically. Structural variations with lithiation was consistent with experimental and sodiation tends to enhance volume expansion than lithiation. Anatase TiO2 and LiTO2 nanotubes of various diameters were generated using NanoWrap builder within MedeA® software. Its outstanding resistance to expansion during lithium insertion and larger surface area make the TiO2 nanotube a promising candidate for rechargeable lithium ion batteries. The outcomes of this study will be beneficial to future development of TiO2 nanotube and other nanostructures. Lastly, our DFTB Slater-Koster potentials were applied to recently discovered trigonal bipyramid (TB), i.e. TiO2 (TB)-I and TiO2 (TB)-II polymorphs, which have enormous 1D channels that provide suitable pathways for mobile ion transport. All structural, electronic properties were consistent with those in literature and all elastic properties agreed excellently with those that were calculated using DFT methods. Finally, the bulk structures of the two polymorphs, were lithiated and sodiated versions and electronic and structural properties were studied, together with the lithiated versions of associated nanostructures consisting of a large number of atoms. Generally, the TiO2 (TB)-I structure was found to be mechanically, energetically more stable and ductile than TiO2 (TB)-II. Hence, it will be beneficial to use TiO2 (TB)-I as an anode material for sodium ion batteries (SIB), due to its unique ductility and larger 1D channels. / National Research Fund (NRF), Department of Science and Innovation (DSI), Material Modelling Centre

Poly(lactic acid) (PLA) is a polymer chain consisting of repeating units of lactic acid (LA) used in various biomedical applications because of its biocompatible features. It is commonly used as a subdermal filler and constitutes as the main ingredient in SculptraR, which is a collagen regenerating filler used to treat lipoatrophy of the cheeks or to rejuvenate the skin. The presence of macrophages triggers a foreign body reaction in response to PLA, which in turn prompts fibroblasts to gradually increase collagen fibers in the dermis. This literature study investigates how physical properties such as Mw, morphology, stereochemistry as well as chemical properties, influence the biological response and degradation of PLA. Additionally, a comparison of other bio stimulants, substituents and copolymers were performed. The aim of this study was constructed in collaboration with Galderma. All aspects that were taken into consideration affected the biological response and degradation to some extent. The degradation of the PLLA microspheres has a noticeable correlation to the biological immune response. An increase in the Mw and degree of crystallinity results in a decrease in degradation rate. Morphology greatly influences the immune response and particle size is vital for the degradation as well as biostimulation. The most suitable stereoisomer of PLA is the (L)-form based on both biological response and degradation. Decomposition of PLLA varies depending on the Mw which is affected by the pH of the surrounding environment. Compared to other substances used in biodegradable products, PLLA is regarded as the most auspicious for a durable result. PDLLA has desirable biological responses but is degraded too fast. PDLA is not suitable as a dermal filler due to its inflammatory response and bad collagen regeneration.

Yes / Construction and demolition waste (CDW) management and recycling practices are crucial for transitioning to a circular economy. This study focuses on the detailed characterization of CDWs, including hollow brick (HB), red clay brick (RCB), roof tile (RT), concrete (C), and glass (G), collected from seven different sites. The CDWs were characterized based on particle size distribution, chemical composition, and crystalline nature. Pozzolanic activity was evaluated through compressive strength measurements of cement mortars with 20% cement replacement by CDWs at 7, 28, and 90 days. The results showed that clayey CDWs exhibited similar physical/chemical properties and crystalline structures. Compositions of Cs varied significantly based on their original materials. CDWs satisfied the minimum strength activity index for supplementary cementitious materials, with pozzolanic activity influenced by fineness and SiO2+Al2O3 contents. The average strength activity indexes for HB, RCB, RT, C, and G were 84.5%, 86.3%, 83.4%, 80.7%, and 75.8%, respectively. Clayey CDWs contributed to mechanical strength development, while Cs' contribution was related to hydration of unreacted cementitious particles. G exhibited the weakest pozzolanic activity due to its coarser particle size. Overall, CDWs demonstrated suitable properties for use as supplementary cementitious materials in PC-based systems.

No description available.