HIV-1 protease plays a crucial role in the late state of the life cycle of HIV virus when it cleaves the viral polyprotein precursors into the structural and functional proteins. If it is effectively inhibited, HIV particles remain immature and noninfectious. The application of highly active antiretroviral therapy (HAART) including protease inhibitors can reduce plasma HIV-1 levels below the detection limit in adherent patients and thus dramatically change their life expectancy. The clinical utility of the first inhibitors was limited by severe side effects, low bioavailability, high pill burdens, and rapid development of viral resistance under the selection pressure of HIV antiretrovirals. To overcome these difficulties, second-generation inhibitors were developed. Despite an indisputable improvement they brought to antiretroviral therapy, the development of new highly active HIV-1 protease inhibitors with optimal pharmacokinetic properties, higher metabolic stability, little off-target activity, and particularly, more favorable resistance profiles is still of high importance. This thesis provides an overview of anti-HIV- drugs including development of substituted metallacarboranes, a new class of potent, unusual, nonpeptidic HIV protease inhibitors with therapeutic potential. Next, the impact of...

Aerobic and anaerobic performance of the upper body (UB) and lower body (LB) were assessed by arm cranking and treadmill tests respectively in a comparison of national (N) and international (I) male gymnasts. Force velocity and Wingate tests were performed using cycle ergometers for both arms and legs. In spite of a significant difference in training volume (4–12 vs. 27–34 h·wk−1 for N and I, respectively), there was no significant difference between N and I in aerobic and anaerobic performance. Upper body and LB maximal oxygen uptake (JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max) values were 34.44 ± 4.62 and 48.64 ± 4.63 ml·kg−1·min−1 vs. 33.39 ± 4.77 and 49.49 ± 5.47 ml·kg−1·min−1, respectively, for N and I. Both N and I had a high lactic threshold (LT), at 76 and 82% of JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max, respectively. Values for UB and LB force velocity (9.75 ± 1.12 and 15.07 ± 4.25 vs. 10.63 ± 0.95 and 15.87 ± 1.25 W·kg−1) and Wingate power output (10.43 ± 0.74 and 10.98 ± 3.06 vs. 9.58 ± 0.60 and 13.46 ± 1.34 W·kg−1) were also consistent for N and I. These findings confirm the consistency of JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max values presented for gymnasts in the last 4 decades, together with an increase in peak power values. Consistent values for aerobic and anaerobic performance suggest that the significant difference in training volume is related to other aspects of perfomance that distinguish N from I gymnasts. Modern gymnastics training at N and I levels is characterized by a focus on relative strength and peak power. In the present study, the high LT is a reflection of the importance of strength training, which is consistent with research for sports such as wrestling. Aerobic and anaerobic performance of the upper body (UB) and lower body (LB) were assessed by arm cranking and treadmill tests respectively in a comparison of national (N) and international (I) male gymnasts. Force velocity and Wingate tests were performed using cycle ergometers for both arms and legs. In spite of a significant difference in training volume (4–12 vs. 27–34 h·wk−1 for N and I, respectively), there was no significant difference between N and I in aerobic and anaerobic performance. Upper body and LB maximal oxygen uptake (JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max) values were 34.44 ± 4.62 and 48.64 ± 4.63 ml·kg−1·min−1 vs. 33.39 ± 4.77 and 49.49 ± 5.47 ml·kg−1·min−1, respectively, for N and I. Both N and I had a high lactic threshold (LT), at 76 and 82% of JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max, respectively. Values for UB and LB force velocity (9.75 ± 1.12 and 15.07 ± 4.25 vs. 10.63 ± 0.95 and 15.87 ± 1.25 W·kg−1) and Wingate power output (10.43 ± 0.74 and 10.98 ± 3.06 vs. 9.58 ± 0.60 and 13.46 ± 1.34 W·kg−1) were also consistent for N and I. These findings confirm the consistency of JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max values presented for gymnasts in the last 4 decades, together with an increase in peak power values. Consistent values for aerobic and anaerobic performance suggest that the significant difference in training volume is related to other aspects of perfomance that distinguish N from I gymnasts. Modern gymnastics training at N and I levels is characterized by a focus on relative strength and peak power. In the present study, the high LT is a reflection of the importance of strength training, which is consistent with research for sports such as wrestling.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-03T15:20:09Z No. of bitstreams: 2 Dissertação - Pedro Ivo de Carvalho - 2017.pdf: 4004894 bytes, checksum: 33f2a48487a0eb9767e85161eae677b4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-03T15:20:21Z (GMT) No. of bitstreams: 2 Dissertação - Pedro Ivo de Carvalho - 2017.pdf: 4004894 bytes, checksum: 33f2a48487a0eb9767e85161eae677b4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-03T15:20:22Z (GMT). No. of bitstreams: 2 Dissertação - Pedro Ivo de Carvalho - 2017.pdf: 4004894 bytes, checksum: 33f2a48487a0eb9767e85161eae677b4 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Several researches aim to discover a best development of new glass-fiber-reinforced composite resins for the manufacture of intraradicular posts with better mechanical properties has been the aim of several researches lately. The reinforcement of composite resin with glass fibers can improve the mechanical properties, such as flexural strength, fracture resistance and compressive strength. Considering that the resin matrix monomers, the photoinitiator system and the interaction with the glass fibers interfere in the homogenization of the composite and in the degree of polymer conversion, the present work had as Objective: To evaluate the influence of different proportions of the monomers Bis-EMA / Bis-GMA / TEGDMA and photoactivator systems based on DFI and camphorquinone on the mechanical properties of a experimental fiberglass reinforced composite resin. Methodology: Ten groups were created (n = 10) using an experimental resin based on methacrylate, having as study factors: 1. Different matrices according to the proportions of monomers Bis-GMA (BG), TEGDMA (TE) and Bis-EMA (BE): And 2. The photoinitiator system: without DFI (SD) salt or DFI (CD) salt. The samples were prepared for the flexural strength (RF) and diametral tensile strength (RTD) tests. Statistical analysis showed that for RF (Mpa) there was significance in the interaction between the factors under study (p = 0.047). The highest result occurred for Group 10 (267.815 ± 45.05) c, followed by Group 9 (242.440 ± 44.83) bc; Group 8 (241.05 ± 44.83) b Group 3 (236.152 ± 26.42) abc. The lowest result occurred in Group 9 (192.450 ± 12.60) a, followed by Group 7 (202.35 ± 28.36) ab; Group 6 (207,240 ± 30,07) ab; Group 2 (209.530 ± 23.16) ab; Group 5 (216,760 ± 30,14); And Gruop 1 (218,880 ± 41,49). For RTD only the presence of DFI salt showed statistical significance (p = 0.001). The addition of the DFI salt in the composite significantly increased results for flexural strength and diametral tensile strength, while the increase of Bis-EMA was significant for better flexural strength results. / A busca pelo desenvolvimento de novos compósitos reforçados com fibra de vidro para a confecção de pinos intrarradiculares com melhores propriedades mecânicas tem sido a base de várias pesquisas atuais. O incremento fibras de vidro silanizadas nas resinas promove melhora nos valores de resistência à flexão, resistência à fratura e resistência compressiva. Tendo em vista que os monômeros da matriz resinosa, o sistema fotoiniciador e a interação com as fibras de vidro interferem na qualidade do compósito e no grau de conversão polimérica, o presente trabalho teve como objetivo avaliar as propriedades mecânicas de um compósito experimental reforçado por fibra de vidro composto por 30% de matriz orgânica, 47,5% de partícula de carga e 22,5% de vibras de vidro curta(3mm), variando proporções de monômeros Bis-EMA, Bis-GMA e TEGDMA e o efeito do sal de difenil-iodônio (DFI) em um sistema fotoiniciador à base de canforoquinona. Dez grupos foram criados (n=10) utilizando uma resina experimental a base de metacrilato, tendo como fatores em estudo: 1. Diferentes matrizes de acordo com as proporções dos monômeros Bis-GMA, TEGDMA e Bis-EMA e 2. O sistema fotoiniciador: sem sal DFI (SD) ou com sal DFI (CD). As amostras foram preparadas para os testes resistência flexural (RF) e resistência à tração diametral (RTD). Análise estatística mostrou que para RF (Mpa) houve significância na interação entre os fatores em estudo (p=0,047). Os melhores resultados foram encontrados para os grupos: Grupo 10 (267,815±45,05)c, seguido por Grupo 9 (242,440±44,83)bc. Para RTD somente a presença do sal DFI demonstrou significância estatística (p=0,001). Em MPa foram observados os maiores resultados: Grupo 10, (35,36±2,61b); Grupo 8, (35,07±6,89b). A adição do sal DFI no compósito aumentou significativamente resultados para resistência flexural e resistência à tração diametral, enquanto que a presença de Bis-EMA foi significante para melhores resultados somente em resistência flexural.

Yes / This paper proposes a method by which material inhomogeneity may be taken into account in a reliability calculation. The method employs Monte-Carlo simulation; and introduces a material strength index, and a standard deviation of material strength to model the variation in the strength of a component throughout its volume. The method is compared to conventional load-strength interference theory. The results are identical for the case of homogeneous material, but reliability is shown to reduce for the same load as the component volume increases. The case of a tensile bar is used to explore the variation of reliability with component volume.

Fiber laser welding (FLW) was used to join advanced high strength steel (AHSS) and high strength steel (HSS); specifically two dual-phase (DP) steels, with ultimate tensile strengths above 980 MPa and with different chemistries (DP980 Rich and DP980 Lean), and a high strength low alloy (HSLA) steel, with an ultimate tensile strength of 450MPa (HSLA450). The welding speed and power were varied to develop a process envelope for minimizing weld concavity. In order to attain welds free of weld concavity a balance of speed and power was required; weld concavity could be reduced by lowering power and increasing speed. Welds with amounts of concavity ranging from 15 % to 35 % were characterized with respect to hardness, tensile and fatigue testing. Tensile results revealed that DP steel was sensitive to weld concavity while HSLA450 was not. At stress amplitudes enduring beyond 1000 cycles, welded specimens exhibited lower fatigue resistance compared to the base metal. Concavity reduced the fatigue life of DP980 steels, where increasing the amount of concavity further reduced the fatigue resistance, while the fatigue resistance of HSLA steel welds was not sensitive to weld concavity. Hardness profiling of the welds revealed that HAZ softening was present in the DP980 steel welds. The amount of HAZ softening was normalized; allowing for comparison of different steels. Welds made by FLW demonstrated reduced softening compared other laser welding types because FLW was capable of welding with lower heat input. A difference in the FZ hardness was observed between the DP980 steels because of the difference in carbon content of the steels; where higher carbon content resulted in higher FZ hardness. Additionally the high cooling rate in FLW created higher fusion zone hardness than the values predicted by Yurioka’s model based on arc welding. Examination of the microstructure revealed that the soft zone of DP980 Lean steel possessed severely tempered martensite and untransformed ferrite while DP980 Rich generated a structure with a mixture of tempered martensite, untransformed ferrite and a small fraction of non-tempered martensite. This difference in HAZ softening was attributed to the alloying content of the DP980 Rich steel the higher alloying content of DP980 Rich steel formed a stable austenite that could exist near the Ac1 temperature and enabled the formation of new martensite in the soft zone. The effects of HAZ softening were apparent in tensile testing where the DP980 Lean steel, which exhibited higher softening, demonstrated by a severe reduction in elongation while the DP980 Rich steel, which had higher resistance to softening, attained elongation comparable to its base metal. HSLA450 exhibited a slight reduction in elongation due to the hardening of the fusion zone. The welded DP980 Rich and HSLA450 steels consistently failed within the base metal, while the DP980 Lean steel failed in the soft zone. The welded DP980 Rich steel also demonstrated limiting dome heights comparable to the base metal while the severe softening in the DP980 Lean led to premature fracture in the soft zone, yielding a larger reduction in the limiting dome height.

Fiber laser welding (FLW) was used to join advanced high strength steel (AHSS) and high strength steel (HSS); specifically two dual-phase (DP) steels, with ultimate tensile strengths above 980 MPa and with different chemistries (DP980 Rich and DP980 Lean), and a high strength low alloy (HSLA) steel, with an ultimate tensile strength of 450MPa (HSLA450). The welding speed and power were varied to develop a process envelope for minimizing weld concavity. In order to attain welds free of weld concavity a balance of speed and power was required; weld concavity could be reduced by lowering power and increasing speed. Welds with amounts of concavity ranging from 15 % to 35 % were characterized with respect to hardness, tensile and fatigue testing. Tensile results revealed that DP steel was sensitive to weld concavity while HSLA450 was not. At stress amplitudes enduring beyond 1000 cycles, welded specimens exhibited lower fatigue resistance compared to the base metal. Concavity reduced the fatigue life of DP980 steels, where increasing the amount of concavity further reduced the fatigue resistance, while the fatigue resistance of HSLA steel welds was not sensitive to weld concavity. Hardness profiling of the welds revealed that HAZ softening was present in the DP980 steel welds. The amount of HAZ softening was normalized; allowing for comparison of different steels. Welds made by FLW demonstrated reduced softening compared other laser welding types because FLW was capable of welding with lower heat input. A difference in the FZ hardness was observed between the DP980 steels because of the difference in carbon content of the steels; where higher carbon content resulted in higher FZ hardness. Additionally the high cooling rate in FLW created higher fusion zone hardness than the values predicted by Yurioka’s model based on arc welding. Examination of the microstructure revealed that the soft zone of DP980 Lean steel possessed severely tempered martensite and untransformed ferrite while DP980 Rich generated a structure with a mixture of tempered martensite, untransformed ferrite and a small fraction of non-tempered martensite. This difference in HAZ softening was attributed to the alloying content of the DP980 Rich steel the higher alloying content of DP980 Rich steel formed a stable austenite that could exist near the Ac1 temperature and enabled the formation of new martensite in the soft zone. The effects of HAZ softening were apparent in tensile testing where the DP980 Lean steel, which exhibited higher softening, demonstrated by a severe reduction in elongation while the DP980 Rich steel, which had higher resistance to softening, attained elongation comparable to its base metal. HSLA450 exhibited a slight reduction in elongation due to the hardening of the fusion zone. The welded DP980 Rich and HSLA450 steels consistently failed within the base metal, while the DP980 Lean steel failed in the soft zone. The welded DP980 Rich steel also demonstrated limiting dome heights comparable to the base metal while the severe softening in the DP980 Lean led to premature fracture in the soft zone, yielding a larger reduction in the limiting dome height.

Analysis of electromagnetic stepper motor at work have been performed. Types of stepper motors and its characteristics have been described generally. The programmes of modelling have been searching using internet and analysed. The programme QuickField 5.2 Studen‘s edition is in consort to demands and requests. Using QuickField 5.2 Student‘s edition the model of electromagnetic motor have been created and experimentations have been performed. Varying displacement of motor magnetic part the distribution of magnetic flux density and magnetic field lines have been analysed. The experimentations involving change of motors mechanical characteristics too (varying air gap between magnetic circuit and secondary part). Teoretical characteristics of distribution of magnetic field energy density, strenth and magnetic flux have been maked and compared. The conclusions and theoretical results specifying operating principle facility of electromagnetic motor. Characteristics of distribution of magnetic field and energy can be used for rating of influence to operation of motor.