Estudo de formulação de massa para aplicação em placas cerâmicas

The sector of civil construction is strongly related to the red ceramic industry. This sector uses clay as raw material for manufacturing of various products such as ceramic plates. In this study, two types of clay called clay 1 and clay 2 were collected on deposit in Ielmo Marinho city (RN) and then characterized by thermogravimetric analysis (TG/DTG), differential thermal analysis (DTA), X-ray diffraction (XRD), X-ray fluorescence (XRF), rational analysis and particle size distribution and dilatometric analyses. Ceramic plates were manufactured by uniaxial pressing and by extrusion. The plates obtained by pressing were produced from the four formulations called 1, 2, 3 and 4, which presented, respectively, the following proportions by mass: 66.5% clay 1 and 33.5% clay 2, 50% clay 1 and 50% clay 2, 33.5% clay 1 and 66.5% clay 2, 25% clay 1 and 75% clay 2. After firing at 850, 950 and 1050 °C with heating rate of 10 °C/min and soaking time of 30 minutes, the following technological properties were determined: linear firing shrinkage, water absorption, apparent porosity, apparent specific mass and tensile strength (3 points). The formulation containing 25% clay 1 produced plates with most satisfactory results of water absorption and mechanical resistance, because of that it was chosen for manufacturing plates by extrusion. A single firing cycle was established for these plates, which took place as follow: heating rate of 2 °C/min up to 600 ºC with soaking time of 60 minutes, followed by heating using the same rate up to 1050 ºC with soaking time of 30 minutes. After this cycle, the same technological properties investigated in the plates obtained by pressing were determined. The results indicate (according to NRB 13818/1997) that the plates obtained by pressing from the mixture containing 25 wt% clay 1, after firing at 1050 °C, reach the specifications for semi-porous coating (BIIb). On the other hand, the plates obtained by extrusion were classified as semi-stoneware (group AIIa)

Influence of prior 810-nm-diode intracanal laser irradiation on hydrophilic resin-based sealer obturation

Dentin wall structural changes caused by 810-nm-diode laser irradiation can influence the sealing ability of endodontic sealers. The objective of this study was to evaluate the apical leakage of AH Plus and RealSeal resin-based sealers with and without prior diode laser irradiation. Fifty-two single-rooted mandibular premolars were prepared and divided into 4 groups, according to the endodontic sealer used and the use or non-use of laser irradiation. The protocol for laser irradiation was 2.5W, continuous wave in scanning mode, with 4 exposures per tooth. After sample preparation, apical leakage of 50% ammoniacal silver nitrate impregnation was analyzed. When the teeth were not exposed to irradiation, the Real Seal sealer achieved the highest scores, showing the least leakage, with significant differences at the 5% level (Kruskal-Wallis test, p = 0.0004), compared with AH Plus. When the teeth were exposed to the 810-nm-diode laser irradiation, the sealing ability of AH Plus sealer was improved (p = 0282). In the Real Seal groups, the intracanal laser irradiation did not interfere with the leakage index, showing similar results in the GRS and GRSd groups (p = 0.1009).

Influência da distribuição granulométrica na estabilidade dimensional de placas cerâmicas de base vermelha

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of surface conditioning methods on the microtensile bond strength of resin composite to composite after aging conditions

Objectives. This study evaluated the effect of two different surface conditioning methods on the repair bond strength of a bis-GMA-adduct/bis-EMA/TEGDMA based resin composite after three aging conditions.Methods. Thirty-six composite resin blocks (Esthet X, Dentsply) were prepared (5 mm x 6 mm x 6 mm) and randomly assigned into three groups for aging process: (a) immersion in citric acid (pH 3.0 at 37 degrees C, 1 week) (CA); (b) boiling in water for 8h (BW) and (c) thermocycling (x5000, 5-55 degrees C, dwell time: 30s) (TC). After aging, the blocks were assigned to one of the following surface conditioning methods: (1) silica coating (30 mu m SiOx) (CoJet, 3M ESPE) + silane (ESPE-Sil) (CJ), (2) phosphoric acid + adhesive resin (Single Bond, 3M ESPE) (PA). Resin composite (Esthet.X (R)) was bonded to the conditioned substrates incrementally and light polymerized. The experimental groups formed were as follows: Gr1:CA + PA; Gr2:CA + CJ Gr3:BW + PA; Gr4: BW + CJ; Gr5:TC + PA; Gr6: TC + CJ. The specimens were sectioned in two axes (x and y) with a diamond disc under coolant irrigation in order to obtain non-trimmed bar specimens (sticks, 10 mm x 1 mm x 1 mm) with 1 mm(2) of bonding area. The microtensile test was accomplished in a universal testing machine (crosshead speed: 0.5 mm min(-1)).Results. The means and standard deviations of bond strength (MPa +/- S.D.) per group were as follows: Gr1: 25.5 +/- 10.3; Gr2: 46.3 +/- 10.1; Gr3: 21.7 +/- 7.1; Gr4: 52.3 +/- 15.1; GrS: 16.1 +/- 5.1; Gr6, 49.6 +/- 13.5. The silica coated groups showed significantly higher mean bond values after all three aging conditions (p < 0.0001) (two-way ANOVA and Tukey tests, alpha = 0.05). The interaction effect revealed significant influence of TC aging on both silica coated and acid etched groups compared to the other aging methods (p < 0.032). Citric acid was the least aggressive aging medium.Significance. Chairside silica coating and silanization provided higher resin-resin bond strength values compared to acid etching with phosphoric acid followed by adhesive resin applications. Thermocycling the composite substrates resulted in the lowest repair bond strength compared to citric acid challenge or boiling in water. (C) 2006 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Detection of immunoglobulin G antibodies to Neospora caninum in humans: High seropositivity rates in patients who are infected by human immunodeficiency virus or have neurological disorders

Considering that little is known about the epidemiology of Neospora caninum infection in humans, particularly in populations with high Toxoplasma gondii infection rates, the present study aimed to investigate the presence of antibodies to N. caninum in T. gondii-seropositive and -seronegative individuals. A total of 256 serum samples divided into four groups (61 samples from human immunodeficiency virus [HIV]-positive patients, 50 samples from patients with neurological disorders, 91 samples from newborns, and 54 samples from healthy subjects) were assessed for N. caninum and T. gondii serologies by indirect fluorescent-antibody test, enzyme-linked immunosorbent assay, and immunoblotting (IB). Immunoglobulin G antibodies to N. caninum were predominantly detected in HIV-infected patients (38%) and patients with neurological disorders (18%), while newborns and healthy subjects showed lower seropositivity rates (5% and 6%, respectively). Seropositivity to N. caninum was significantly associated with seropositivity to T. gondii in both HIV-infected patients and patients with neurological disorders. Seroreactivity to N. caninum was confirmed by IB, with positive sera predominantly recognizing the 29-kDa antigen of N. caninum. The results of this study indicate the presence of N. caninum infection or exposure in humans, particularly in HIV-infected patients or patients with neurological disorders, who could have opportunistic and concurrent infections with T. gondii. These findings may bring a new concern for the unstable clinical health of HIV-infected patients and the actual role of N. caninum infection in immunocompromised patients.

Influence of light, plant density and disinfection in spore germination of fern blechnum brasiliense desv. blechnaceae

The present assay had as objective evaluating spore germination of Blechnum brasiliense in relation to light, plant density and disinfection. The assay was carried out at Jaboticabal, Sào Paulo State, Brazil, from February, 22 to June, 30, 1996. The experimental design was randomized blocks on a factorial scheme (3x2x2), consisting of 12 treatments, three environments (shade-house, dark-house and germination camera), 2 densities (0.005 grs and 0.010 grs of spores/treatment) and presence or absence of disinfection. The leaf coverage area (130 days) and the number of days necessary to germinate were evaluated. The germination camera data were not analysed because they were insignificant; consequently, the remining data were analysed on a 2×2×2 scheme. The shade-house provided larger green covering area and a faster germination. The density of 0.0 lOg of spore/treatments presented the largest green covering area. The supply of partial light was necessary for good germination. The interaction between the environment and the density had significant effect on the green covering area.

Avaliação técnica e socioeconômica da cultura da uva para mesa em pequenas propriedades rurais da Regional de Jales (SP)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caracterização de uma jazida visando a garantia da qualidade de matérias-primas para indústria cerâmica de revestimentos

Pós-graduação em Geologia Regional - IGCE

Metodologia para o gerenciamento integrado saudável dos resíduos sólidos da bacia da estrada nova do município de Belém/PA

O presente trabalho tem o objetivo de criar uma metodologia para o Gerenciamento Integrado dos Resíduos Sólidos (GIRS) que associa a prática pertinente ao tema, com programas que envolvam a comunidade, no sentido de manter o meio ambiente limpo e saudável, tendo como cenário o município de Belém, especificamente a Bacia Hidrográfica da Estrada Nova (BHEN). Objetiva também identificar porquê, apesar da BHEN possuir coleta de resíduos e serviços de limpeza realizada pela Secretaria Municipal de Saneamento (SESAN), a mesma permanece, constantemente, suja, principalmente, de lixo e entulho lançados nas vias públicas e canais de drenagem dessa bacia. A pesquisa de campo consistiu de entrevistas com os principais atores desse trabalho, a comunidade da BHEN. Inova no município um modelo de programas de participação da população com o nome de Cidadania e Participação Ativa da Comunidade (CIPAC) propondo 20 programas: Mascote da educação ambiental; Boteco em boteco; Eu amo minha cidade; Alô comunidade; TV SOS “Meio ambiente”; Rádio “Desperta comunidade; Coral e teatro “Reciclar”; Educa móvel; Coleta seletiva nas escolas; O meio ambiente pede carona; Centro de memória; A escola do lixo; Conhecer o lixo; Comunidade nota 10; Futuro verde; Coleta seletiva “porta a porta” Implantação dos LEVs; Criação das unidades básicas ecológicas; Criação da central de reciclagem de entulho; Criação das unidades de triagem de materiais recicláveis; Criação das cooperativas de catadores e carroceiros. Faz uma previsão de investimentos para implantação e manutenção desses programas assim como o retorno do investimento aplicado com a implantação. Como resultado, apresenta um novo modelo, baseado na prática, como sustentação para o estabelecimento de uma política municipal, de acordo com a Lei da Política Nacional de Resíduos Sólidos (PNRS) que tramita no Congresso Nacional. Também foram identificados parâmetros capazes de identificar a inadequação do processo atual de coleta de lixo e dos serviços de limpeza nessa bacia. Esses resultados alcançados permitem concluir que grande parte da população da BHEN não está preparada para aderir a um programa de Gestão de Resíduos Sólidos (GRS), que tenha como ponto de partida o GIRS. O grau de escolaridade e o nível de conhecimento da comunidade não representam obstáculos para isso, mas sim a falta de programas que envolvam a sua participação, a coleta de resíduos e serviços de limpeza urbana corretamente prestados, pois, atualmente, na pesquisa de campo realizada, foram visivelmente reprovados. Finalmente, ainda conclui que somente com a implantação de um GIRS, com apoio do CIPAC o meio ambiente seria consideravelmente beneficiado, mas não resolveria os graves problemas ambientais da BHEN, será necessária a melhoria de todos os sistemas de infra-estrutura urbana nessa importante bacia, para um efeito realmente mais saudável. É importante destacar que, no momento atual, as propostas apresentadas por este trabalho são consideradas bastante oportunas, pois com o inicio da implantação do Programa de Recuperação Urbano-Ambiental da Bacia da Estrada Nova (PROMABEM) pela Administração Municipal financiado pelo Banco Interamericano de Desenvolvimento (BID), os problemas sanitários e ambientais dessa importante bacia têm grande probabilidade de ser resolvidos.

Geosynthetic-Reinforced Soil Structure Built to Restore Original Geometry of a 12 m High Slope After Failure Using Local Soil

This paper presents a study case in which a geosynthetic-reinforced soil (GRS) structure was used to rebuild a 12 m high slope after its failure. The failed slope is located between the parking lot of a private company and a public school. Due to surrounding structures restrictions, this project required a solution with rapidity in execution. In addition, as a requirement established by its owner, this structure should recover the original geometry of the slope. Besides the importance regarding surrounding constructions, an interesting aspect of this study case relies on the versatility of geosynthetic materials. A woven geotextile was used as reinforcement. Five other geosynthetic materials were used in this study case. Facing comprised a geocell filled with local soil cover and grass mats, resulting in a green facing. A geonet was used to hold the grass mats in place before grass roots development. Regarding the drainage system, geocomposite drains and geopipes were installed to drain subsurface water. A nonwoven geotextile was used as filter in drainage trenches, which were placed near the structure toe. Additionally to the GRS structure, the lower portion of the slope was reinforced with soil nailing technique. The face of the nailed soil portion was covered with sandbags and shotcrete. It emphasizes the flexibility of GRS structures regarding their application with other technical options in Geotechnical Engineering. The economic aspect of this study case also deserves attention. It did not require soil transportation and other design and construction steps, e.g. concrete structures design and construction.

Comparison Between Micro- and Macrosurgical Techniques for the Treatment of Localized Gingival Recessions Using Coronally Positioned Flaps and Enamel Matrix Derivative

Background: The aim of this study is to compare the macro- and microsurgery techniques for root coverage using a coronally positioned flap (CPF) associated with enamel matrix derivative (EMD). Methods: Thirty patients were selected for the treatment of localized gingival recessions (GRs) using CPF associated to EMD. Fifteen patients were randomly assigned to the test group (TG), and 15 patients were randomly assigned to the control group (CG). The microsurgical approach was performed in the TG, and the conventional macrosurgical technique was performed in the CG. The clinical parameters evaluated before surgery and after 6 months were GR, probing depth, relative clinical attachment level, width of keratinized tissue (WKT), and thickness of keratinized tissue (TKT). The discomfort evaluation was performed 1 week postoperative. Results: There were no statistically significant differences between groups for all parameters at baseline. At 6 months, there was no statistically significant difference between the techniques in achieving root coverage. The percentage of root coverage was 92% and 83% for TG and CG, respectively. After 6 months, there was a statistically significant increase of WKT and TKT in TG only. Both procedures were well tolerated by all patients. Conclusions: The macro- and microsurgery techniques provided a statistically significant reduction in GR height. After 6 months, there was no statistically significant difference between the techniques regarding root coverage, and the microsurgical technique demonstrated a statistically significant increase in WKT and TKT. J Periodontol 2010;81:1572-1579.

Influence of prior 810-nm-diode intracanal laser irradiation on hydrophilic resin-based sealer obturation

Dentin wall structural changes caused by 810-nm-diode laser irradiation can influence the sealing ability of endodontic sealers. The objective of this study was to evaluate the apical leakage of AH Plus and RealSeal resin-based sealers with and without prior diode laser irradiation. Fifty-two single-rooted mandibular premolars were prepared and divided into 4 groups, according to the endodontic sealer used and the use or non-use of laser irradiation. The protocol for laser irradiation was 2.5W, continuous wave in scanning mode, with 4 exposures per tooth. After sample preparation, apical leakage of 50% ammoniacal silver nitrate impregnation was analyzed. When the teeth were not exposed to irradiation, the Real Seal sealer achieved the highest scores, showing the least leakage, with significant differences at the 5% level (Kruskal-Wallis test, p = 0.0004), compared with AH Plus. When the teeth were exposed to the 810-nm-diode laser irradiation, the sealing ability of AH Plus sealer was improved (p = 0282). In the Real Seal groups, the intracanal laser irradiation did not interfere with the leakage index, showing similar results in the GRS and GRSd groups (p = 0.1009).

Galactose Recognition by the Apicomplexan Parasite Toxoplasma gondii

Toxosplasma gondii is the model parasite of the phylum Apicomplexa, which contains numerous obligate intracellular parasites of medical and veterinary importance, including Eimeria, Sarcocystis, Cryptosporidium, Cyclospora, and Plasmodium species. Members of this phylum actively enter host cells by a multistep process with the help of microneme protein (MIC) complexes that play important roles in motility, host cell attachment, moving junction formation, and invasion. T. gondii (Tg)MIC1-4-6 complex is the most extensively investigated microneme complex, which contributes to host cell recognition and attachment via the action of TgMIC1, a sialic acid-binding adhesin. Here, we report the structure of TgMIC4 and reveal its carbohydrate-binding specificity to a variety of galactose-containing carbohydrate ligands. The lectin is composed of six apple domains in which the fifth domain displays a potent galactose-binding activity, and which is cleaved from the complex during parasite invasion. We propose that galactose recognition by TgMIC4 may compromise host protection from galectin-mediated activation of the host immune system.

Att bli fri från anorexi – En kvalitativ studie av professionella behandlingsmetoder samt självhjälp

Forskning vad gäller självhjälpsgrupper och dess faktiska verkan är överlag begränsad och trots flera års forskning finns det fortfarande ingen behandling som ger mycket goda resultat för många patienter med anorexi. Vetenskaplig utvärdering av olika behandlingsmetoder saknas i stor utsträckning och en genomgång av den vetenskapliga litteraturen visar att det inte finns några läkemedel med dokumenterad effekt vid anorexi. Varför bildas självhjälpsgrupper? Varför räcker det inte med de professionella behandlingsmodellerna? Dessa frågor ämnar jag att finna svar på i min uppsats. Jag har forskat kring professionella behandlingsmetoder samt självhjälp. Mina kärnfrågor i uppsatsen är: vilka olika professionella behandlingsmetoder finns och vad är självhjälp? Jag har valt en kvalitativ ansats på min uppsats. Jag vill beskriva, förklara och jämföra självhjälpsgrupper för anorexi och deras sätt att se sjukdomen och hur de arbetar för att ta sig ur den. Detta i förhållande till professionella behandlingsmetoder. Mina bakgrundsstudier med förklaringsmodeller av anorexi och tillgängliga professionella behandlingsmodeller har jag gjort genom en systematisk genomgång. Min studie görs enligt kvalitativ metod och genom en systematisk beskrivning. Jag har också gjort en systematisk sökning av de tillgängliga litteraturer som finns på biblioteket respektive Internet. Självhjälpsgrupper bör ses som ett komplement till de professionella behandlingsmetoderna snarare än ett alternativ, och man bör inte utesluta en professionell behandling för att istället vara med i en självhjälpsgrupp. Däremot bör man absolut inte underskatta den kraft och styrka det kan ge, att träffa andra människor i samma situation. Att samtala om det gemensamma problem man har, stötta varandra och känna gemenskap är en stark drivkraft i kampen att bli frisk från anorexi

L'efficienza degli indici azionari: un'analisi empirica

La studio dell’efficienza di un indice azionario ha accresciuto la propria importanza nell’industria dell’asset management a seguito della diffusione dell’utilizzo di benchmark e investimenti indicizzati. Il presente lavoro valuta il livello di efficienza dei principali indici del mercato azionario statunitense, dell’Area Euro e italiano. Lo studio empirico ricorre a quattro misure di efficienza: il GRS, un test small-sample multivariato fondato sul CAPM; il test large sample di Wald, implementato tramite una simulazione bootstrap; il test GMM, che è stato applicato in una cornice non-gaussiana attraverso una simulazione block bootstrap; la misura di efficienza relativa di Kandel e Stambaugh. I risultati empirici forniscono una prova evidente della superiore efficienza degli indici equiponderati. Questa conclusione è interpretata sulla base della letteratura scientifica esistente, analizzando le diverse cause di ordine teorico ed empirico che sono state proposte.