Extração, caracterização estrutural e atividades farmacológicas do olginato obtido da alga marrom Lobophora variegata (Lamouroux) Oliveira Filho, 1977

The alginic acid or alginates are acidic polysaccharides found in brown seaweed widely used in food, cosmetic, medical and pharmaceutical industry. This paper proposes the extraction, chemical characterization and verification of the pharmacological activities of brown seaweed variegata Lobophora . The alginate was extracted from the seaweed Lobophora variegata and part was sulphated for comparative purposes. The native extract showed 42% total sugar, 65% uronic acid, 0,36 % protein and 0% of sulfate, while the sulfate showed 39% , 60%, 0.36% and 27,92 % respectively. The presence of a sulfate group may be observed by the metachromasia with toluidine blue in electrophoresis system and characteristic vibration 1262,34 cm-1 in infrared spectroscopy connections assigned to S = O. We observed the formation of films and beads of native alginate, where more concentrated solution 6% resulted in a thicker and more consistent film. Native alginate showed proliferative activity at concentrations (25 and 50 mcg), (50 mg) and (100 mg) in 3T3 cell line in 24h, 48h and 72h, respectively , as the sulfated (100 mg) in 24 . Also showed antiproliferative or cytotoxic activity in HeLa cells of strain, (25 and 100 mg), (25 and 100 mg) and (25, 50 and 100 mg), to native, now for the sulfate concentrations (100 mg) in 24 (25, 50 and 100 mg) in 48 hours, and (50 and 100 mg ) 72h. For their antioxidant activity, the sulfated alginates have better total antioxidant activity reaching 29 % of the native activity while 7.5 % of activity . For the hydroxyl radical AS showed high inhibition ( between 77-83 % ) in concentrations, but the AN surpassed these numbers in the order of 78-92 % inhibition. The reducing power of AN and AS ranged between 39-82 % . In the method of ferric chelation NA reached 100 % chelating while the AS remained at a plateau oscillating 6.5%. However, in this study , we found alginates with promising pharmacological activities, to use in various industries as an antioxidant / anti-tumor compound

Avaliação de concretos reforçados por confinamento com manta de fibra de vidro estrutural e pré-impreganada

Due to the occurrence of diseases in the use of structural reinforcements in composites, with presentation of concrete blanket detachment, has been identified the need to evaluate the performance of concrete reinforced with glass fiber. This study aims to evaluate these concretes by means of testing methodologies, using concrete with low resistance with structural reinforcement for confinement by preimpregnated glass fiber and traditional fiberglass blanket. The first stage of work was the development of methodologies for analysis, opting for four types, such as the acoustic survey, strength to compressive, the pull-off and ultrasound. Next, tests were carried out using the four selected methodologies in 30 of proof-of-specimens by 5x10 cm, 15 were reinforced with the traditional fiberglass blanket with 5specimens exposed to test a marine environment of marine coastline of Natal-RN and 15 were reinforced with a pre-impregnated glass fiber blanket, as well as 5specimens exposed to a test environment of the marine coastline of Natal-RN. After conducting the acoustic survey, it has been verified a lack of delaminating and air bubbles in the samples, confirming the absence of gross shortcomings in the implementation of the ribs both the traditional fiberglass blanket and in the preimpregnated fiber glass blanket. After carrying out methods of pull-off and compressive strengthening test it was observed that the reinforced proof-bodies with pre-impregnated glass blanket showed maximum stresses higher than the traditional fiberglass blanket; consequently a greater grip with the formation of a smaller area of . fracture, unlike traditional glass mat, which showed lower maximum stresses, with a greater area of fracture. It was also found that the traditional fiberglass blanket presented detachment of blanket-concrete interface, unlike the pre-impregnated fiberglass blanket, which showed a better grip on the blanket-concrete interface. In the trial of ultrasound there was no presence of cracks in the blanket-concrete interface, yielding to both blankets good compactness of the concrete. At the end of this work, they were developed and proposed two methods of testing for evaluation of reinforced concrete structures with composites, for standardization, the acoustic survey and pull-off

Estudo de massa cerâmica triaxial visando à otimização do ciclo de queima da indústria de cerâmica estrutural

Over recent years the structural ceramics industry in Brazil has found a very favorable market for growth. However, difficulties related to productivity and product quality are partially inhibiting this possible growth. An alternative for trying to solve these problems and, thus, provide the pottery industry the feasibility of full development, is the substitution of firewood used in the burning process by natural gas. In order to contribute to this process of technological innovation, this paper studies the effect of co-use of ceramic phyllite and kaolin waste on the properties of a clay matrix, verifying the possible benefits that these raw materials can give to the final product, as well as the possibility of such materials to reduce the heat load necessary to obtain products with equal or superior quality. The study was divided into two steps: characterization of materials and study of formulations. Two clays, a phyllite and a residue of kaolin were characterized by the following techniques: laser granulometry, plasticity index by Atterberg limits, X-ray fluorescence, X-ray diffraction, mineralogical composition by Rietveld, thermogravimetric and differential thermal analysis. To study the formulations, specifically for evaluation of technological properties of the parts, was performed an experimental model that combined planning involving a mixture of three components (standard mass x phyllite x kaolin waste) and a 23 factorial design with central point associated with thermal processing parameters. The experiment was performed with restricted strip-plot randomization. In total, 13 compositional points were investigated within the following constraints: phyllite ≤ 20% by weight, kaolin waste ≤ 40% by weight, and standard mass ≥ 60% by weight. The thermal parameters were used at the following levels: 750 and 950 °C to the firing temperature, 5 and 15 °C/min at the heating rate, 15 and 45min to the baseline. The results showed that the introduction of phyllite and/or kaolin waste in ceramic body produced a number of benefits in properties of the final product, such as: decreased absorption of water, apparent porosity and linear retraction at burn; besides the increase in apparent specific mass and mechanical properties of parts. The best results were obtained in the compositional points where the sum of the levels of kaolin waste and phyllite was maximal (40% by weight), as well as conditions which were used in firing temperatures of 950 °C. Regarding the prospect of savings in heat energy required to form the desired microstructure, the phyllite and the residue of kaolin, for having small particle sizes and constitutions mineralogical phases with the presence of fluxes, contributed to the optimization of the firing cycle.

Efeito da tecnologia de microondas nas propriedades tecnológicas dos componentes de cerâmica estrutural

O processamento térmico de materiais cerâmicos via energia de microondas, no estágio atual, vem ganhando cada dia mais importância, tendo em vista suas inúmeras aplicações, como por exemplo: aplicação de microondas na área de processamento mineral (aquecimento de minérios antes da moagem, secagem, redução carbotérmica de óxidos minerais, lixiviação, fusão, pré-tratamento de minérios e concentrados de ouro refratário, regeneração de carvão, etc. de acordo com Kigman & Rowson, 1998). Em virtude de uma série de vantagens em potencial, frente aos métodos convencionais de aquecimento, como redução no tempo de processamento; economia de energia; diminuição do diâmetro médio das partículas e melhoramento nas propriedades tecnológicas em geral, esta tecnologia vem se destacando. Neste contexto, o objetivo geral deste trabalho, é desenvolver uma pesquisa visando identificar e caracterizar novas opções de matérias-primas cerâmicas como argilas, feldspatos e caulins que sejam eficazes para definir a formulação de uma ou mais massas para produção de componentes de cerâmica estrutural com propriedades físicas, mecânicas e estéticas adequadas após passarem por sinterização convencional e por energia de microondas destacando as vantagens desta última. Além dos requisitos técnicos e de processo, as formulações apresentadas deverão atender às expectativas de preço e de logística de fornecimento. No estudo foram conformados corpos-de-prova por extrusão e prensagem, sinterizados em fornos microondas e convencional, sob ciclos de queima mais rápidos que os atualmente praticados. As matérias-primas foram caracterizadas e analisadas, utilizando as técnicas de fluorescência por raios X (FRX), difração por raios X (DRX), análise térmica diferencial (DTA), análise térmica gravimétrica (DTG), análise granulométrica (AG), microscopia eletrônica de varredura (MEV), absorção d agua (AA), massa especifica aparente (MEA), porosidade aparente (PA), retração linear (RL) e tensão de ruptura e flexão (TRF). Os resultados obtidos indicaram que as propriedades tecnológicas de Absorção de água (AA) e Tensão de Ruptura e flexão (TRF), proposto no trabalho foram adquiridos com sucesso e estão bem além do limite exigido pelas especificações das normas da ABNT NBR 15.270/05 e 15.310/09

Novos monômeros obtidos a partir do metacrilato de glicidila, bisfenol A e 4, 4 isopropilidenodicicloexanol : síntese, caracterização estrutural e propriedades de compósitos para utilização em resinas de restauração dental

Nowadays, composite resins are the direct restorative materials more important in dental clinical performance, due to their versatility and aesthetic excellence. Bis-GMA (2,2-bis[4(2-hydroxy-3-metacryloxypropoxy)phenil]propane) is the base monomer more frequently used in restorative composite resins. However, this monomer presents some disadvantages, such as high viscosity and two aromatic rings in its structure that can promote allergic reactions to the humans. In this work, the main purpose was to synthesize new monomers from glycidyl methacrylate to use in dental restorative materials. Structural characterization of the monomers was carried out through FTIR and NMR 1H, and eight composites were produced from the new monomers, by addition of silane-treated alumino silicate particles (inorganic filler) and a photocuring system (camphorquinone and ethyl 4-dimethylaminebenzoate). The composites were analyzed by environmental scanning electronic microscopy and the water sorption and solubility, compressive strength and elastic modulus were determined. A commercial composite resin [Z100 (3M)] was used to comparison effect. The new composites presented general characteristics similar to the commercial ones; however, they didn t present the properties expected. This behavior was attributed to the lower degree of monomer reaction and to the granulometry and size distribution of the mineral filler in the polymeric matrix

Efeito da velocidade de aquecimento nas propriedades de produtos da cerâmica estrutural

Heating rate is one of the main variables that determine a fire cycle. In industrial processes that use high temperatures, greater fire great can reduce the cost of production and increase productivity. The use of faster and more efficient fire cycles has been little investigated by the structural ceramic industry in Brazil. However, one of the possibilities that aims at modernizing the sector is the use of roller kilns and the inclusion of natural gas as fuel. Thus, the purpose of this study is to investigate the effect of heating rate on the technological properties of structural ceramic products. Clay raw materials from the main ceramic industries in the state of Rio Grande do Norte were characterized. Some of the raw materials characterized were formulated to obtain the best physical and mechanical properties. Next, raw materials and formulations were selected to study the influence of heating rate on the final properties of the ceramic materials. The samples were shaped by pressing and extrusion and submitted to rates of 1 °C/min, 10 °C/min and 20 °C/min, with final temperatures of 850 °C, 950 °C and 1050 °C. Discontinuous cycles with rates of 10 °C/min or 15 °C/min up to 600 °C and a rate of 20 °C/min up to final temperature were also investigated. Technological properties were determined for all the samples and microstructural analysis was carried out under a number of fire conditions. Results indicate that faster and more efficient fire cycles than those currently in practice could be used, limiting only some clay doughs to certain fire conditions. The best results were obtained for the samples submitted to slow cycles up to 600 °C and fast fire sinterization up to 950 °C. This paper presents for the first time the use of a fast fire rate for raw materials and clay formulations and seeks to determine ideal dough and processing conditions for using shorter fire times, thus enabling the use of roller kilns and natural gas in structural ceramic industries

Diversidade de invertebrados em cavernas calcárias do oeste potiguar : subsídios para a determinação de áreas prioritárias para conservação.

It is estimated that the Brazilian karst areas sum about 200.000 km2. The caves, one of the main components of karst, are important windows into the biological studies on hypogean environments. In Rio Grande do Norte are known 563 caves, and 476 of them are in the municipalities of Baraúna, Felipe Guerra, Governador Dix-Sept Rosado, Apodi and Mossoró, the Western region of the State. However, like in the rest of the country, the cave fauna of the State is still poorly understood. This study used data from invertebrates harvested in 47 caves and aimed to analyze the effect of environmental change between the dry and rainy seasons in the communities of cave invertebrates, characterize these communities and evaluate the relationships between morphological and biotic variables of the caves and surroundings, and to define priority areas for conservation of cave environments of the study area from biotic parameters. Strong effects were found in the community structure of cave invertebrates due environmental changes between seasons, with values of total richness, abundance, diversity and ecological complexity significantly higher in the rainy season. It was possible to assess how the morphology of the cave and the external environment variables affect the biotic system, so that the variety of resources, forest cover in the vicinity, the area of the cave and its entrance were the variables that best explained the structure communities of cave invertebrates in the region. High values of total richness of invertebrates (36,62 ± 14,04 spp / cave) and troglomorphic species (61 species, mean 1,77 ± 2,34 spp / cave) were found and, given the biological relevance in the context of the area national and the imminent anthropogenic pressures existing, we defined four priority areas for actions aiming cave biodiversity conservation in the region.

Analise estrutural do galactano acidico dos ovos de pomacea lineata e avaliacao de suas atividades proliferativa e antiinflamatoria

The acidic galactan (AG) was obtained by extraction and proteolysis by acetone precipitation of the eggs of the mollusc Pomacea lineata. Its structure was elucidated by a combination of chemical analysis, the intrinsic viscosity and NMR spectroscopy 1D and 2D. Biological aspects of AG were evaluated by in vivo testing of healing and peritonitis induced (anti-inflammatory activity) and in vitro assays of cytotoxicity (MTT). This polymer showed a simple structure without the presence of sulfate and uronic acids in its structure. Its intrinsic viscosity and relative were evaluated at 0.44 ± 0.05 and 1.744± 0.07 dl.g-1. Spectroscopy showed that the AG has a constitution composed predominantly of β-D-galactosis, and β-D-glucosamine-NAcetil that comes in a smaller proportion in chain. The character of this acidic polysaccharide is given by the presence of pyruvate in the molecule, forming a cyclic acetal of six states, located in β-D-galactosis. The involvement of AG in the healing process was evaluated and the histological analysis revealed that there was so early in the process of healing, a great stimulation of macrophages with granuloma formation. Suggesting that AG may have promoted the advance of biological events required for tissue healing. In the trial of the GA-induced peritonitis showed dose dependent, demonstrating the anti-inflammatory effect at concentrations above 20 mg/kg, and confirming its inflammatory character and the concentration of 1mg/kg. In vitro tests used in the GA concentration of 1000 μg/mL showed proliferative activity by stimulating the growth of 3T3 cells, corroborating the findings in vivo and demonstrating the absence of cytotoxic activity

Iniqüidade em saúde: uma extensão das desigualdades sociais no sistema público de saúde do Brasil (2003-2006)

This issue analises the unevenness in the brazilian system of public health care as an extension of socials inequities. It is a theoretical study based in a historical method, using empirical camp from academic, corporation and institution researchs, along the period 2002-2006. Equality and effectiveness in health systems are analitical basic cathegories grap in the root of the doctrine, principles and organization of the Unique Health System, in which sectorial actions are inserted. Discuss the estructural prodution and determined those inequalities through some social determiners of health system: income, land, food securitiy, nutritional situation, basic sanitation, epidemiological inequities and public management policy. Carry out a thematic review over health social production, it formlation and the goals of social policies, as well as the insertion of the equality principle in the assistance system, in the frame of the running public health regulations. It uses reflections that enlighted the correlation between the process of political-institutional actions and equity on health assistance. Analized the pertinency of sectorial reorganizational strategies on basic attendance, confronting the hipothesis that those strategies reinforce social inequities in health system, because it organize diferential assistance levels over not equal baselines. The results show up that social inequalities, even remaining, have had a small decrease; that the selectiviness of actual public policies and the duplication of the health system, increases the differences within and between the social classes and configures the assistance as inequal. The basic care system has great shortages that also appeares in middle and complex assistance levels. As conclusion, it remarks that the health assintance system, even with it integrality has limits; structural problems on material conditions of living and health system could not be reversed only with institutional legal arragements; by the contrary, in border conditions, these strategies produce policies that reinforce inequities, neglecting the equity principle of the system in which frame, they work. One patina of this tim

A banalização da injustiça social no cotidiano de trabalho : a propósito da violência no trabalho e ameaça à saúde do trabalhador

Analyzes the factors that unleash violence by banalization of the problems and health questions of workers in a federal public institution, in Natal/RN. It analyzes transformations in the world of the work, with its politic, social and economic determinatives and its relation to the worker health. Boarding the violence in the work enviroment and its implications to the worker health, focusing on the banalization of problems faced by the workers as a kind of violence in and with the work. It was chosen an analitic methodology with qualitative approach, through the collection tecnic and information analyzes according to the thematic oral history, with recorders of authorized personal narratives, through individual interview with a semi-structured guide. In the analyzis of results it were made empiric cathegories: the daily work enviroment and its influence to the worker profession and life; the violence presents in the work enviroment and its consequences to the worker life and health; the banalization of the social injustice, due to violence against the worker that broked their dreams concerned to the nursing contribution. The results revealed the ordinary work of these workers showing enviromental and organizational unhealthy conditions, caracterized by physical and tecnical insecurity; absence and disqualification of instrumental and human supplies; overload and complexity service; bad distribution of the duties and pressure to the deadline and productivity, producing tension, conflict and anxiety related to the users, colleagues, superiors and to the duties. In the work enviroment, it were identified a external violence, caracterized by physical and verbal aggresion, psychic suffering, worker depreciation; and internal, caracterized by: moral and psychological molestations and accupational structural violence. These kinds of violence bring consequences to the life, that is, professional, economic and moral order of factors and to the health by biological, mental and emocional factors. The banalization of social injustice during the daily work was discussed in the aspects of banalization of problems and work conditions, the health, qualification banalizations and professional valorization. The workers expectatives pointed out to the necessity of: secure conditions of work; trainning and tecnical assistance; politics of attention to the physical, mental and social health to the workers and their family. We conclude the enviromental and organizational conditions of the workers interviewed do not offer physical and tecnical security that they need to the execution of their activities, neither offer comfort or physical and psychological satisfactions. The politic the instituition has used points out to the depreciation and inhumanization of them producing feelings as unsatisfaction, frustation and indignation related to the institution and the work, bringing suffering and physical and mental sicking. We noticed the most terrible violence found in the work enviroment is the banalization of social injustice related do the problems and health of these workers, producing a slowly debility and simbolic death of their lifes. Therefore, it is necessary the implementation of a politic that promotes assurance, health and integral education, valorization and humanization of these workers

A pessoa idosa com doença crônica não transmissível atendida em serviços de média complexidade na cidade de Natal/RN

The demographic and epidemiological transition process caused by a declining in birth rates and in mortality, also changes occurred in morbidity and mortality is represented by the increasing of the aging population and the raising of chronic diseases. These diseases are characterized by multiple etiologies, risk factors, long latency period, a prolonged evolution, non-infectious origin and it has association with functional impairment and disability. Thus, elderly with chronic non-communicable disease has priority because they belong to a vulnerable group to get affection of comorbidities in aging, with increased demand and spending on health services. This study is aimed to analyse the understanding of elderly people with chronic non comunicable disease in the medium complexity service as a contribution to the improvement of health care in the city of Natal / RN. This is a descriptive and exploratory study with a quantitative approach, carried out at the Specialized Center for Elderly Health Care and at the Pescadores Hospital. The population was composed of 4,180 persons with a sample of 124 elderly aged above 60 years, attended in these medium complexity services. The instrument, a structured form, adapted from a questionnaire for monitoring risk and protective factors for chronic disease of the Ministry of Health. To collect data was was used the interview form containing demographic data, habits, health status and health care services. The results were processed using the Statistical Package for Social Science, version 18.0, analyzed by simple statistics. It was found that most seniors were female, predominantly between 70 and 74 years old, married, with a brown skin tone and Catholic religion, more than half had incomplete basic education, family income between one to two minimum wages and living with their families. Regarding the interviewers lifestyle, 94.4%, of them ate chicken and 97.6%, fruits, it was observed a reduction in smoking, alcoholism habits and physical activity according to the increasing age, 58.1 and 18.5% had insomnia18,5 % used sleeping pills. The elderly (51.6%) reported using services in times of sickness, seeking primary care at first (30.6%), 52% did not receive referral and was looking for free demand (38.7%). The most reported morbidity was hypertension, followed by musculoskeletal disorders. Regarding the difficulties in seeking health services, the delay in treatment and the waiting line were the most cited by the elderly. Almost all of them reported no activities to promote health in these services and those who received individual counseling on chronic diseases. Almost always, the health professionals who care of them, were mostly doctors followed by nurses. Based on the results presented, it is considered that the health services of medium complexity must undergone a more continuous dialogue with other attention level and focus on actions of health promotion and prevention. It is also recommended the necessity for qualified professionals to delivery health care to elderly and the implementation of protocols by a multidisciplinary health team, intending to provide better and continous care for the elderly with chronic diseases. The healthcare professionals who served them, were mostly physicians, followed by nurses. Through the results presented, it is considered that the medium complexity healthcare services need to perform a more continuous dialogue with the other levels of attention focusing attention to the health promotion and prevention actions. It is also recommended the necessity for qualified professionals to delivery healthcare for the elderly, in addition, a protocol implementation for the multidisciplinary health care team, to provide better care, and also the care continuity to elderly with chronic diseases

Evidências de validação de um protocolo para assistência às pessoas com úlceras venosas em serviços de alta complexidade

Venous ulcers are lesions resulting from chronic venous insufficiency, venous valvular abnormalities and venous thrombosis. Its occurrence has been growing with the increase in life expectancy of the world population. Considered as fundamental aspects in the approach to the person with venous ulcer care with the interdisciplinary approach, adoption of protocol-specific knowledge, technical skill, coordination between levels of care complexity of the Health System and active participation of patients and their families, a holistic perspective. The construction of a clinical protocol for people with venous ulcers can help professionals of high complexity services in patient assessment and the establishment of quality care in a systematic way and focused on the factors that interfere with wound healing. Thus, this study aimed to analyze the evidence of validation of a clinical protocol for people with venous ulcers treated at high-complexity services. This is a methodological study with a quantitative approach, developed in three stages: literature review, evidence of content validity and evidence of validation in the clinical context. Approved by the Federal University of Rio Grande do Norte Research Ethics Committee (Opinion: 147.452 and CAAE: 07556312.0.0000.5537). The literature review was conducted in August and September 2012, becoming the basis for the construction of the protocol. Then the evidence of content validity, which included 53 judges (experts) selected by the Lattes platform to evaluate the protocol items was performed. The judges were contacted by e-mail and rated the protocol via Google Docs . After analyzing the ratios obtained in this step, which reported kappa between 0.75 and 0.96 and between 0.80 and 0.98 IVC, and the suggestions of the judges, the protocol was adjusted and subjected to empirical evidence to validate the clinical setting at the University Hospital Onofre Lopes in Natal / RN. Evidence of validation in the clinical setting involved 4 judges who acted in pairs (paired) evaluated 32 patients with venous ulcers in the clinical context of high complexity. In both stages, we used the Kappa Index and Content Validity Index to analyze the responses of the judges. The parameters set as acceptable for these indices were: Kappa ≥ 0.61 and Content Validity Index > 0.80. Any evidence of content validity, as evidence of validation in the clinical context, the protocol items that have not reached Kappa and Content Validity Index established indices were excluded and some items were modified or added after suggestions. The process of content validation evidence and evidence of validation in the clinical setting allowed the improvement of the protocol for the care of people with venous ulcers initially proposed. The initial version of the protocol, built from the literature, contained 15 categories and 108 items; after evidence of content validity, remained the reduction to 15 categories with 91 items; the final version, clinically validated, is composed of the same 15 categories, 76 items. The protocol was validated in its content and in the clinical aspect, so we accepted the alternative hypothesis in the study. This protocol may contribute to the care system, allowing tailor behaviors and promote greater resolution in the treatment of people with venous ulcers in health services of high complexity

Modelos para análise e dimensionamento de painéis de alvenaria estrutural

The main objective of this thesis was the study of bracing panels of structural masonry, by applying the Finite Element Method and Strut and Tie Method. It was analyzed the following aspects: the effect of orthotropy on the behavior of the panels; distribution of horizontal forces between panels for buildings; comparison between Equivalent Frame and Finite Elements models; panels design with the Strut and Tie Method. The results showed that one should not disregard the orthotropy, otherwise this can lead to models stiffer than the real. Regarding the distribution of horizontal forces, showed that the disregard of lintels and shear deformation leads to significant differences in the simplified model. The results showed also that the models in Finite Element and Equivalent Frame exhibit similar behavior in respect to stiffness of panels and stress distribution over the sessions requested. It was discussing criteria for designing Strut and Tie Method models in one floor panels. Then, the theoretical strength these panels was compared with the rupture strength of panels tested in the literature. The theoretical maximum strength were always less than the rupture strength of the panels obtained in tests, due to the fact that the proposed model cannot represent the behavior of the masonry after the start of the panel cracking due to plasticization of the reinforcement

Estudo numérico do comportamento de muros de arrimo em alvenaria estrutural de blocos vazados

Usually masonry structures has low tension strength, hence the design to flexural efforts can results in high reinforcement ratio, specification of high unit and prism strength, structural members with larger section dimensions and modification in structural arrangement to be possible to use masonry members. The main objective of this study is to evaluate the stiffness, the efforts distribution and the effect of horizontal elements (girders) and vertical elements (counterforts) distribution on the behavior of masonry blocks retaining walls. For this purpose, numerical modeling was performed on typical retaining wall arrangements by varying the amount and placement of horizontal and vertical elements, beyond includes elements simulating the reactions of the soil supporting the foundation of the wall. The numerical modeling also include the macro modeling strategy in which the units, mortar and grout are discretized by a standard volume that represents the masonry elastic behavior. Also, numerical model results were compared with those ones of simplified models usually adopted in bending design of masonry elements. The results show horizontal displacements, principal and shear stresses distribution, and bending moments diagrams. From the analysis it was concluded that quantity and manner of distribution of the girders are both important factors to the panel flexural behavior, the inclusion of the foundation changed significantly the behavior of the wall, especially the horizontal displacements, and has been proposed a new way of considering the flanges section of the counterforts

Metodologia para adaptação de microarquiteturas microprogramadas soft-core à uma ISA padrão: estudo do impacto sobre a complexidade de hardware para o padrão MIPS

In academia, it is common to create didactic processors, facing practical disciplines in the area of Hardware Computer and can be used as subjects in software platforms, operating systems and compilers. Often, these processors are described without ISA standard, which requires the creation of compilers and other basic software to provide the hardware / software interface and hinder their integration with other processors and devices. Using reconfigurable devices described in a HDL language allows the creation or modification of any microarchitecture component, leading to alteration of the functional units of data path processor as well as the state machine that implements the control unit even as new needs arise. In particular, processors RISP enable modification of machine instructions, allowing entering or modifying instructions, and may even adapt to a new architecture. This work, as the object of study addressing educational soft-core processors described in VHDL, from a proposed methodology and its application on two processors with different complexity levels, shows that it s possible to tailor processors for a standard ISA without causing an increase in the level hardware complexity, ie without significant increase in chip area, while its level of performance in the application execution remains unchanged or is enhanced. The implementations also allow us to say that besides being possible to replace the architecture of a processor without changing its organization, RISP processor can switch between different instruction sets, which can be expanded to toggle between different ISAs, allowing a single processor become adaptive hybrid architecture, which can be used in embedded systems and heterogeneous multiprocessor environments