Teses e Dissertações

Nesta secção apresenta-se o resumo da primeira tese de doutoramento defendida na Universidade Lusófona e algumas teses de mestrado em Educação e em Educação Especial, domínio cognitivo e motor

Effect of abutment angulation in the retention and durability of three overdenture attachment systems: An in vitro study

PURPOSE. This in vitro study investigated and compared the durability and retention of three types of attachments. MATERIALS AND METHODS. Three commercially available attachments were investigated: Clix (R), Dalbo-Plus (R) and Locator (R). In total, 72 samples of these attachments were placed in the acrylic resin forms and subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH 7 and 37 degrees C. The abutments were placed at angulations of 0 degrees, 10 degrees and 20 degrees. The retention force was recorded at the beginning and after 540, 1080, 2160, 3240, 4320 and 5400 insertion-removal cycles. RESULTS. The results revealed that there were significant differences in the average values of the insertion/removal force due to angulation (F ((2.48)) = 343619, P<.05) and the type of attachment (F ((7.48)) = 23.220, P<.05). CONCLUSION. Greater angulation of the abutments was found to influence the retention capacity of the attachments, and the fatigue test simulating 5 years of denture insertion and removal did not produce wear in the metal abutments.info:eu-repo/semantics/publishedVersio

Effect of plug-filling, Testing velocity and temperature on the tensile strength of strap repairs on aluminium structures

In this work, an experimental study was performed on the influence of plug-filling, loading rate and temperature on the tensile strength of single-strap (SS) and double-strap (DS) repairs on aluminium structures. Whilst the main purpose of this work was to evaluate the feasibility of plug-filling for the strength improvement of these repairs, a parallel study was carried out to assess the sensitivity of the adhesive to external features that can affect the repairs performance, such as the rate of loading and environmental temperature. The experimental programme included repairs with different values of overlap length (L O = 10, 20 and 30 mm), and with and without plug-filling, whose results were interpreted in light of experimental evidence of the fracture modes and typical stress distributions for bonded repairs. The influence of the testing speed on the repairs strength was also addressed (considering 0.5, 5 and 25 mm/min). Accounting for the temperature effects, tests were carried out at room temperature (≈23°C), 50 and 80°C. This permitted a comparative evaluation of the adhesive tested below and above the glass transition temperature (T g), established by the manufacturer as 67°C. The combined influence of these two parameters on the repairs strength was also analysed. According to the results obtained from this work, design guidelines for repairing aluminium structures wer

Tensile behaviour of single and double-strap repairs on aluminium structures

In this work, an experimental study was performed on the influence of plug filling, loading rate and temperature on the tensile strength of single-strap (SS) and double-strap (DS) repairs on aluminium structures. The experimental programme includes repairs with different values of overlap length (LO=10, 20 and 30 mm), and with and without plug filling. The influence of the testing speed on the repairs strength is also addressed (considering 0.5, 5 and 25 mm/min). Accounting for the temperature effects, tests were carried out at room temperature, 50ºC and 80ºC. This will permit a comparative evaluation of the adhesive tested below and above the Glass Transition Temperature (Tg), established by the manufacturer at 67ºC. The global tendencies of the test results concerning the plug filling and overlap length analyses are interpreted from the fracture modes and typical stress distributions for bonded repairs. According to the results obtained from this work, design guidelines for repairing aluminium structures were recommended

Eficácia do gasto público: uma avaliação do FNE, FNO e FCO

During the period 2000-2003, this paper evaluates and compares the efficacy of Financing Constitutional Fund of the Northeast (FNE), North (FNO) and Center-West (FCO) loans using propensity score estimates of firms that have received loans and of others that have not. In relation to FNE, the general result indicates a positive impact on the growth rate of employee number and no impact on the growth rate of wages paid for firms. In relation to FNO and FCO, there is not possible to indicate any kind of impact on the analyzed variables.Este artigo avalia e compara a eficácia dos empréstimos dos recursos do Fundo Constitucional de Financiamento do Nordeste (FNE), do Fundo Constitucional de Financiamento do Norte (FNO) e do Fundo Constitucional de Financiamento do Centro-Oeste (FCO), no período 2000-2003, a partir das estimativas de propensity score das firmas beneficiadas com recursos desses fundos constitucionais e de um conjunto de firmas não-beneficiadas por esses fundos. Em relação ao FNE, o resultado geral diz respeito ao impacto positivo sobre a taxa de variação do número de empregados e à ausência de impacto sobre a taxa de variação do salário médio pago pelas firmas. No que concerne ao FNO e FCO, não é possível apontar qualquer tipo de impacto nas variáveis em análise

Taper angle optimization of scarf repairs in carbon-epoxy laminates

The increasing use of Carbon-Fibre Reinforced Plastic (CFRP) laminates in high responsibility applications introduces an issue regarding their handling after damage. The availability of efficient repair methods is essential to restore the strength of the structure. The availability of accurate predictive tools for the repairs behaviour is also essential for the reduction of costs and time associated to extensive tests. This work reports on a numerical study of the tensile behaviour of three-dimensional (3D) adhesively-bonded scarf repairs in CFRP structures, using a ductile adhesive. The Finite Element (FE) analysis was performed in ABAQUS® and Cohesive Zone Models (CZM’s) was used for the simulation of damage in the adhesive layer. A parametric study was performed on two geometric parameters. The use of overlaminating plies covering the repaired region at the outer or both repair surfaces was also tested as an attempt to increase the repairs efficiency. The results allowed the proposal of design principles for repairing CFRP structures

Ações do Programa de Educação Tutorial (PET): intervenções para prevenção do bullying

O texto relata a experiência vivenciada com estudantes de uma escola pública municipal de Teresina, PI, para trabalhar a temática do bullying, suas formas de prevenção, identificação e consequências. O trabalho foi realizado usando como método a educação problematizadora de Paulo Freire. Apesar dos estudantes perceberem práticas de agressões o assunto é pouco discutido e são vários os tabus existentes. As intervenções educativas realizadas contribuíram para sensibilizar os estudantes e demais atores sociais da escola para a adoção de práticas de relações saudáveis como forma de prevenção da violência e despertou à atenção para a criação de formas de enfrentamento dessa problemática

Effects of therapeutic and aerobic exercise programs in temporomandibular disorder-associated headaches

Objective: To assess the effects of three 8-week exercise programs on the frequency, intensity, and impact of headaches in patients with headache attributed to temporomandibular disorder (TMD).&nbsp;Methodology: Thirty-six patients diagnosed with headache attributed to TMD participated in the study and were divided into three groups of 12 patients: a therapeutic exercise program (G1, mean age: 26.3±5.6 years), a therapeutic and aerobic exercise program (G2, mean age: 26.0±4.6 years), and an aerobic exercise program (G3, 25.8±2.94 years). Headache frequency and intensity were evaluated using a headache diary, and the adverse headache impact was evaluated using the Headache Impact Test (HIT-6). The intensity was reported using the numerical pain rating scale. These parameters were evaluated twice at baseline (A01/A02), at the end of the 8-week intervention period (A1), and 8–12 weeks after the end of the intervention (A2).&nbsp;Results: At A1, none of the G2 patients reported having headaches, in G1, only two patients reported headaches, and in G3, ten patients reported headache. The headache intensity scores (0.3 [95% CI: -0.401, 1.068]), (0.0 [95% CI: -0.734, 0.734]) and HIT-6 (50.7 [95% CI: 38.008, 63.459]), (49.5 [95% CI: 36.808, 62.259]), significantly decreased in G1 and G2 at A1. At A2 headache intensity scores (0.5 [95% CI: -0.256, 1.256]), (0.0 [95% CI: -0.756, 0.756]) and HIT-6 (55.1 [95% CI: 42.998, 67.268]), (51.7 [95% CI: 39.532, 63.802]) in G1 and G2 haven’t change significantly. The effects obtained immediately after the completion of the intervention programs were maintained until the final follow-up in all groups.&nbsp;Conclusion: The programs conducted by G1 (therapeutic exercises) and G2 (therapeutic and aerobic exercise) had significant results at A1 and A2