94 resultados para KGF
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The research aimed to produce sheets of particles with waste processing of Eucalyptus sp bonded with urea-formaldehyde and evaluate the effect of pressure variation in the quality of the boards produced. To do so, the Boards made were divided into two treatments depending on the pressing pressure of 30 to 40 kgf / cm². Once pressings, climatized, the particleboards have been sectioned in test samples, and underwent physical-mechanical tests for determining density, swelling and water absorption, modulus of rupture and elasticity in static bending and internal linking. The particleboards pressed at 40 kgf / cm ² showed the best results
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The purpose of this study was to investigate the validity of critical force test from maximal lactate steady state (MLSS) during resistance test using straight bench press. Five healthy male volunteers aged (22.6 ± 2.88 years), weight (76.3 ± 11.49 kg) e height (182.6 ± 7.54cm), trained in resistance exercise, and performed four diferent test to determine: one maximal effort (1RM), critical force using the critical power model (force vs 1/time limit - 20, 25 and 30% 1RM). The CF was the linear coefficient and the anaerobic impulse capacity (CIA) was the angular. MLSS was determined using loads of 80, 90, 100 and 110% of critical force. Blood lactate samples were abtained at each 300sec between each stage of total 1200sec. Maximal 30s test (M30) was accomplished with load of 25% of body weight in SBP. The results showed that the 1 RM was 79.4 Kgf (± 16.98), CF 10.1N (± 2.25), CIA 1756.82 N.s (± 546.96) and the R² 0.984 (± 0,02). The MLSS occurs at 100% CF load. The lactate concentration at the MLSS was 2.2 mmol/L (± 0.77). Significant correlation was observed between MLSS and CF on SBP (r = 0.88 p = 0.05). In M30 the minimum, mean and peak power were (25.0 ± 4.9, 28.0 ± 4.9, and 30.0 ± 4.6 kgf.rps, respectively). The fatigue index was 18.0% (± 6,8). The M30 was significantly correlated with Ppeak and Pmean (r = 0.98 for both, p = 0.003). The CF means has been validated to predict the resistance training and the CIA show to be a representative anaerobic parameter in straight bench press.
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This work presents a study that aims to validate the fatigue analyses developed on finite element commercial software, ANSYS Workbench. It was based on mechanical tests development of traction and hardness, to verify the mechanical properties of material that the shaft was manufactured (ABNT 1045 steel), it was developed bend test, with purpose to prove the confiability degree of computational analyses, obtaining the maximum stress in a work condition determined with 40 [kgf] of load applied, and at the end, was developed the fatigue test to obtain the number of cycles that the transmission shaft can support in a work condition with 8 [kgf] of load applied. The results obtained during the work present, have to be quite satisfactory with the theoretically expected
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This study aimed to evaluate the effect of Er:YAG (L) and diamond drills (DD) on: 1) the microshear bond strength (MPa); 2) the adhesive interface of two-step (TS) – Adper Scotchbond Multipurpose and one-step (OS) adhesives – Adper EasyOne, both from 3M ESPE. Material and methods: According to the preparation condition and adhesives, the samples were divided into four groups: DD_TS (control); DD_OS; L_TS and L_OS. 60 bovine incisors were randomly divided into experimental and groups: 40 for microshear bond strength (n = 10) and 20 for the adhesive interface morphology [6 to measure the thickness of the hybrid layer (HL) and length of tags (t) by CLSM (n = 3); 12 to the adhesive interface morphology by SEM (n = 3) and 2 to illustrate the effect of the instruments on dentine by SEM (n = 1)]. To conduct the microshear bond strength test, four cylinders (0.7 mm in diameter and 1 mm in height with area of adhesion of 0.38 mm) were constructed with resin composite (Filtek Z350 XT – 3M ESPE) on each dentin surface treated by either L or DD and after adhesives application. Microshear bond strength was performed in universal testing machine (EMIC 2000) with load cell of 500 kgf and a crosshead speed of 0.5 mm / min. Adhesive interface was characterized by thickness of hybrid layer (HL) and length of tags (t) in nm, with the aid of UTHSCSA ImageTool software. Results: Microshear bond strength values were: L_TS 34.10 ± 19.07, DD_TS 24.26 ± 9.35, L_OS 33.18 ± 12.46, DD_OS 21.24 ± 13.96. Two-way ANOVA resulted in statistically significant differences only for instruments (p = 0.047). Mann-Whitney identified the instruments which determined significant differences for HL thickness and tag length (t). Concerning to the adhesive types, these differences were only observed for (t). Conclusion: It can be concluded that 1) laser Er:YAG results in higher microshear bond strength values regardless of the adhesive system (TS and OS); 2) the tags did not significant affect the microshear bond strength; 3) the adhesive interface was affected by both the instruments for cavity preparation and the type of adhesive system used.
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In view of the low loading values commonly employed in dentistry, a load-application device (LAD) was developed as option to the universal testing machine (UTM), using strain gauge analysis. The aim of this study was to develop a load-application device (LAD) and compare the LAD with the UTM apparatus under axial and non-axial loads. An external hexagonal implant was inserted into a polyurethane block and one EsthetiCone abutment was connected to the implant. A plastic prosthetic cylinder was screwed onto the abutment and a conical pattern crown was fabricated using acrylic resin. An impression was made and ten identical standard acrylic resin patterns were obtained from the crown impression, which were cast in nickel-chromium alloy (n=10). Four strain gauges were bonded diametrically around the implant. The specimens were subjected to central (C) and lateral (L) axial loads of 30 kgf, on both devices: G1: LAD/C; G2: LAD/L; G3: UTM/C; G4: UTM/L. The data (με) were statistically analyzed by repeated measures ANOVA and Tukey's test (p<0.05). No statistically significant difference was found between the UTM and LAD devices, regardless of the type of load. It was concluded that the LAD is a reliable alternative, which induces microstrains to implants similar to those obtained with the UTM.
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Pós-graduação em Odontologia Restauradora - ICT
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Pós-graduação em Odontologia Restauradora - ICT
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Pós-graduação em Odontologia Restauradora - ICT
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Recent orthodontic bonding materials have aimed to reduce the working time of the clinician, by simplifying the acid etching procedure by applying self-etching primer adhesive systems. However, the adhesion quality of these materials still demands investigation. Thus, the present study aimed to evaluate the bond strengths of three different adhesive systems. A hundred and eighty bovine lower incisors were cut and embebbed in acrylic resin matrices, in which orthodontic brackets were bonded with Transbond XT (2n = 60), Transbond XT Self Etching Primer (2n = 60) e Tyrian (2n = 60). For each composite, bond strength tests were executed immediately (n = 30) and 24 hours (n = 30) after the bonding, in the assay machine Versat 2000 (Pantec), by applying 500 Kgf of load at 1mm/min of velocity. Transbond XT, Transbond XT Self Etching Primer and Tyrian presented, respectively, average values of bond strength of 7.43, 7.09 and 3.41 MPa at the time immediately, and 7.42, 8.81 and 5.35 MPa at 24 hours after the bonding, where differences were statistically significant at 5% between Tyrian and Transbond groups at both observation times. It was concluded that Tyrian was the material that presented significant lower bond strength with regard to Transbond groups that were similar.
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A força de preensão manual tem sido relatada como determinante no desempenho de empunhadura em modalidades como lutas e escalada. Este estudo teve por propósito avaliar a aptidão de força isotônica máxima e de preensão manual em praticantes e não praticantes de montaria em touros, a fim de obter parâmetros de referência desta população. Foram avaliados 20 sujeitos em dois grupos, sendo 10 classificados como atletas de montaria e 10 não-atletas. A avaliação da força de preensão manual foi realizada em dinamômetro em posição convencional (DP) e específica (DE), com ambas as mãos (D e E). A força isotônica máxima foi determinada pelo teste de uma repetição máxima (1RM) e também foram obtidas medidas de circunferência dos segmentos, bem como a composição corporal por protocolo de dobras cutâneas. Os valores das variáveis foram comparados pelo teste-t (ρ ≤ 0,05) para dados independentes. As relações entre os valores de força e características antropométricas foram traçadas pelo coeficiente de Pearson. Os resultados para AMT em DPD (43.8±6.8 kgf), DPE (39.4±7.7 kgf), DED (44.9±5.6 kgf) e DEE (39.8±8.3 kgf) comparados aos apresentados por n-AMT em DPD (47.0±3.0 kgf), DPE (42.2±6.1 kgf), DED (49.2±1.5 kgf) e DEE (46.2±4.1 kgf) apresentaram diferenças apenas para DED e DEE. A força nos testes de 1RM (supino reto: 73.2±12.0 kg e 82.0±12.0 kg; rosca direta: 45.2±8.9 kg e 43.8±8.9 kg; tríceps pulley: 67.0±6.3 kg e 72.0±6.3 kg; e puxada posterior: 73.5±8.5 kg e 73.7±7.5 kg) não mostram diferenças entre os grupos. A influência sobre a dinamometria apresenta-se diferente entre os grupos, sendo relevante a força de flexão do cotovelo em AMT e a antropometria e força isotônica para n-AMT. Conclui-se que as características morfo-funcionais de membros superiores não demandam especificidade à montaria em touros.
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A força de preensão manual tem sido relatada como determinante no desempenho de empunhadura em modalidades como lutas e escalada. Este estudo teve por propósito avaliar a aptidão de força isotônica máxima e de preensão manual em praticantes e não praticantes de montaria em touros, a fim de obter parâmetros de referência desta população. Foram avaliados 20 sujeitos em dois grupos, sendo 10 classificados como atletas de montaria e 10 não-atletas. A avaliação da força de preensão manual foi realizada em dinamômetro em posição convencional (DP) e específica (DE), com ambas as mãos (D e E). A força isotônica máxima foi determinada pelo teste de uma repetição máxima (1RM) e também foram obtidas medidas de circunferência dos segmentos, bem como a composição corporal por protocolo de dobras cutâneas. Os valores das variáveis foram comparados pelo teste-t (ρ ≤ 0,05) para dados independentes. As relações entre os valores de força e características antropométricas foram traçadas pelo coeficiente de Pearson. Os resultados para AMT em DPD (43.8±6.8 kgf), DPE (39.4±7.7 kgf), DED (44.9±5.6 kgf) e DEE (39.8±8.3 kgf) comparados aos apresentados por n-AMT em DPD (47.0±3.0 kgf), DPE (42.2±6.1 kgf), DED (49.2±1.5 kgf) e DEE (46.2±4.1 kgf) apresentaram diferenças apenas para DED e DEE. A força nos testes de 1RM (supino reto: 73.2±12.0 kg e 82.0±12.0 kg; rosca direta: 45.2±8.9 kg e 43.8±8.9 kg; tríceps pulley: 67.0±6.3 kg e 72.0±6.3 kg; e puxada posterior: 73.5±8.5 kg e 73.7±7.5 kg) não mostram diferenças entre os grupos. A influência sobre a dinamometria apresenta-se diferente entre os grupos, sendo relevante a força de flexão do cotovelo em AMT e a antropometria e força isotônica para n-AMT. Conclui-se que as características morfo-funcionais de membros superiores não demandam especificidade à montaria em touros.
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Pós-graduação em Odontologia Restauradora - ICT
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Pós-graduação em Odontologia Restauradora - ICT