Tecnologia construtiva de revestimento externo de argamassa com projeção contínua.

Os métodos construtivos de revestimento externo produzidos com argamassa vêm evoluindo ao longo do tempo, apresentando como maior mudança a substituição da aplicação manual pela projeção mecânica. Atualmente destaca-se no mercado o sistema de execução de revestimento externo com argamassa industrializada e projeção mecânica contínua com bombas helicoidais. Por se tratar de uma tecnologia ainda não muito utilizada pelas construtoras brasileiras, faltam dados confiáveis acerca de seu potencial de ganho de produtividade, redução de perdas, diminuição de contingente de mão de obra, exigências de infraestrutura para aplicação e custos envolvidos. Sem parâmetros confiáveis, adotar a tecnologia significa assumir um nível de risco elevado e isto dificulta a tomada de decisão por parte das construtoras e, por consequência, dificulta-se a evolução tecnológica. Buscando contribuir para o necessário avanço nas tecnologias de produção de revestimentos de edifícios, o objetivo desta pesquisa é estabelecer parâmetros em relação à tecnologia de produção de revestimentos de fachada que empregam argamassa com projeção contínua. Para tanto, buscou-se informações em referências como teses, dissertações, textos técnicos, normas nacionais, dentre outras, bem como, acompanhou-se e avaliou-se os resultados da implantação de um método construtivo de revestimento de argamassa com projeção mecânica contínua em uma construtora de São Paulo. Foram realizados um protótipo e um piloto que contribuíram para o desenvolvimento da tecnologia por meio de apresentação de soluções para os problemas encontrados, do levantamento de melhores práticas e de dados para o cálculo de índices de produtividade e perda. Buscou-se, portanto, a consolidação da tecnologia de projeção contínua na construtora anteriormente mencionada e no mercado em geral.

Resistência ao cisalhamento de contactos solo-rocha

Nos estudos referentes à estabilidade de maciços rochosos, é de capital importância a identificação dos planos de fraqueza do maciço rochoso. Estes planos de fraques condicionam a estabilidade do maciço, tanto mais quanto mais adversa a posição dos mesmos com relação ás tensões cisalhantes atuantes. De modo geral, os planos de fraqueza consistem de camadas e intercalações de rocha fraca ou alterada, ou de fraturas e outras descontinuidades as quais são frequentemente preenchidas por solo. Quando uma intercalação de solo, argilito, folhelho, etc, apresenta-se em intercalação a camadas de rochas duras, (ou mesmo de preenchimentos alterados de fraturas e falhas) tem sido prática comum adotar a resistência ao cisalhamento do material de preenchimento como sendo o valor mais baixo da resistência da descontinuidade. Entretanto, conforme foi sugerido por Patton (1968), existe a hipótese de que a prática acima não seja válida, e que a resistência ao cisalhamento do contacto seja inferior à obtida para o solo de preenchimento propriamente dito. O objetivo desta investigação é o de iniciar o estudo da resistência ao cisalhamento de contactos solo-rocha, e de compara essa resistência às do solo e da rocha obtidas separadamente

Pocas, pero contundentes palabras en la obra de Mendes da Rocha

La extensa producción arquitectónica de Mendes da Rocha resulta difícil de clasificar bajo el reduccionismo de los ‘ismos’ porque supone una revisión crítica y de síntesis de una modernidad replanteada. Se abordan tres aproximaciones al conjunto de su obra. Primera: la nueva tradición moderna de la arquitectura brasileña atendiendo a la implicación urbana de sus obras y a la escala de intervención (objeto, contexto, territorio). Segunda: la simbiosis entre arte y técnica desde una poética que tiende a la reducción de los elementos y a la simbolización de arquetipos. Tercera: la relativa al modo en que el maestro se enfrenta a las obras de intervención en el patrimonio recurriendo a una estética de la pobreza. Pocas, pero contundentes palabras: sencillez y humildad como atributos de la rotundidad.

Conservação de cereja com aplicação de revestimento comestível

Dissertação apresentada à Escola Superior Agrária do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Fruticultura Integrada.

El secreto de ultratumba. Ensayo dramatico en tres actos y en verso, original de Manuel Rocha y Chabre. Estrenado en el Teatro Betancourt de esta ciudad el 26 de enero de 1898.

Mode of access: Internet.

Filosofía moral derivada de la alta fuente del grande Aristóteles Stagirita. Escriviola en toscano ... Don Manuel Thesauro ... tradúcela en español D. Gomez de la Rocha y Figueroa.

Mode of access: Internet.

Apuntes del informe que presenta a la 2a sala del Tribuno Superior del Estado el c. lic. Joaquín D. Casasús por d. Ignacio G. Rocha : apoderado de d. Jesús Andrade en el juicio que éste sigue contra los parcioneros de "San Pedro y San Pablo" : y en la apelación promovida contra la sentencia de 1a instancia.

"Como una ampliación del informe publicamos en un apéndice los capítulos XIII y XIV de los Comentarios á la Ordenanza de minas de Gamboa"--Advertencia.

COMPARAÇÃO DAS FORÇAS DE DEFLEXÃO LIBERADAS ENTRE OS FIOS ORTODÔNTICOS ESTÉTICOS E SUA RELAÇÃO COM O REVESTIMENTO

O objetivo do presente estudo consistiu em comparar as forças de deflexão in vitro entre fios estéticos e fio NiTi, para verificar a força máxima e da região platô e determinar sua correlação com o diâmetro do fio com e sem revestimento. Foram realizados dez ensaios de sete marcas comerciais de arcos précontornados, sendo seis fios estéticos (Invu (I), Optis (O), Flexy Super Elastic Esthetic (FSEE), Niticosmetic (N), Orthocosmetic Elastinol (OE) e Pro Form Coated Nitanium (PFCN)) e um fio NiTi superelástico (Nitinol Super Elastic (NSE)), aplicando-se o teste de curvatura de três pontos, associado a máquina de ensaios universal EMIC. Desenvolveu-se um dispositivo com braquetes cerâmicos (Transcend), cujos fios foram presos por elásticos modulares, sendo obtidos os valores da força de deflexão em 3,0, 2,0 e 1,0mm. O diâmetro dos fios com e sem revestimento foram mensurados com o especímetro digital Micromaster. A análise de variância a um critério (p<0,05) mostrou diferença significante entre os fios e o teste post-hoc de Tukey determinou que a força de deflexão em 3mm para o Ode deflexão (2-1mm) na região platô e mostrou que os fios O, FSEE e N apresentaram forças constantes. O fio da N apresentou o maior diâmetro entre as amostras, enquanto que os fios NSE e O, os menores. O Coeficiente de Correlação de Pearson mostrou que houve correlação entre o diâmetro do fio e a força de deflexão. Pode se concluir que há diferenças entre as forças produzidas pelos fios estéticos e que a força é diretamente proporcional ao seu diâmetro do fio com e sem revestimento para todas as deflexões, ou seja, quanto maior o diâmetro, maior a força produzida.

Avaliação da influência de cinza da casca de arroz em cimentos para poços de petróleo submetidos à injeção de vapor

Reservoirs that present highly viscous oils require methods to aid in their recovery to the surface. The elev ated oil viscosity hinders its flow through porous media and conventional recovery methods have not obtained significant efficiency. As such, the injection of steam into the reservoir through an injection well has been the most widely used method of therma l recovery, for it allows elevated volumes of recovery due to the viscosity reduction of the oil, facilitating the oil’s mobility within the rock formation and consequently into the production well where it will be exploited. On the other hand, the injecti on of vapor not only affects the fluids found in the rock pores, but the entire structure that composes the well where it is injected due to the high temperatures used in the process. This temperature increment is conducted to the cement, found in the annu lus, responsible for the isolation of the well and the well casing. Temperatures above 110 ̊C create new fazes rich in calcium in the cement matrix, resulting in the reduction of its permeability and the consequential phenomenon of mechanical resistance ret rogression. These alterations generate faults in the cement, reducing the well’s hydraulic isolation, creating insecurity in the operations in which the well will be submitted as well as the reduction of its economic life span. As a way of reducing this re trograde effect, this study has the objective of evaluating the incorporation of rice husk ash as a mineral additive substitute of silica flour , commercially utilized as a source of silica to reduce the CaO/SiO 2 ratio in the cement pastes submitted to high temperatures in thermal recovery. Cement pastes were formulated containing 20 and 30% levels of ash, apart from the basic paste (water + cement) and a reference paste (water + cement + 40% silica flour) for comparison purposes. The tests were executed th rough compression resistance tests, X - Ray diffraction (XRD) techniques, thermogravimetry (TG), scanning electron microscopy (SEM) and chemical anal ysis BY X - ray fluorescence (EDS) on the pastes submitted to cure at low temperatures (45 ̊C) for 28 days following a cure at 280 ̊C and a pressure of 2,000 PSI for 3 days, simulating vapor injection. The results obtained show that the paste containing 30% r ice shell ash is satisfactory, obtaining mechanical resistance desired and equivalent to that of the paste containing 40% silica flour, since the products obtained were hydrated with low CaO/SiO 2 ratio, like the Tobermorita and Xonotlita fases, proving its applicability in well subject to vapor injection.

Análise da eficácia de um refrigerador doméstico com condensador modificado: revestimento com meio poroso dissipativo

The development of home refrigerators generally are compact and economic reasons for using simplified configuration. The thermodynamic coefficient of performance ( COP ) is limited mainly in the condenser design for reasons of size and arrangement ( layout ) of the project ( design ) and climatic characteristics of the region where it will operate. It is noteworthy that this latter limitation is very significant when it comes to a country of continental size like Brazil with diverse climatic conditions. The COP of the cycle depends crucially on the ability of heat dissipated in the condenser. So in hot climates like the northeast, north, and west-central dispel ability is highly attenuated compared to the south and southeast regions with tropical or subtropical climates when compared with other regions. The dissipation in compact capacitors for applications in domestic refrigeration has been the focus of several studies, that due to its impact on reducing costs and power consumption, and better use of the space occupied by the components of refrigeration systems. This space should be kept to a minimum to allow an increase in the useful storage volume of refrigerator without changing the external dimensions of the product. Due to its low cost manufacturing, wire on tube condensers continue to be the most advantageous option for domestic refrigeration. Traditionally, these heat exchangers are designed to operate under natural convection. Not always, the benefits of greater compactness of capacitors for forced outweigh the burden of pumping air through the external heat exchanger. In this work we propose an improvement in convective condenser changing it to a transfer mechanism combined in series with conductive pipes and wire to a moist convective porous medium and the porous medium to the environment. The porous media used in the coating was composed of a gypsum plaster impregnated fiber about a mesh of natural cellulosic molded tubular wire mesh about the original structure of the condenser , and then dried and calcined to greater adherence and increased porosity. The proposed configuration was installed in domestic refrigeration system ( trough ) and tested under the same conditions of the original configuration . Was also evaluated in the dry condition and humidified drip water under natural and forced with an electro - fan ( fan coil ) convection. Assays were performed for the same 134- refrigerant charge e under the same thermal cooling load. The performance was evaluated in various configurations, showing an improvement of about 72 % compared with the original configuration proposed in humidification and natural convection.

Revestimento decorativo monocamada pigmentado, com resíduo de vidro temperado, para aplicação em fachadas

Although efficient from a technical point of view, mortar layers that make up the traditional masonry coating (slurry mortar, plaster and plaster) have to be in contradiction with the new construction technologies and more efficient methods of consumption and work rationalization. From an environmental point of view, the recovery of waste into new composites for the building has been a growing strand of studies in the scientific community, may prove to be a cost-effective solution in some cases. Thus, this research proposes the development of a mortar Decorative Coating Monolayer (RDM), for use in facades, produced on site, incorporating tempered glass waste (RVT) in the cement matrix, as a partial substitute for aggregate. Therefore, we adopted the binder respect / aggregate of 1: 6 (by volume), consistency index 250mm ± 20, sand substitution levels of glass waste 20%, 50% and 80% and relative water / cement varied in many traits. Two additives were used, a polymer, styrene-butadiene-based, and other chemical, besides mineral and silica fume inorganic pigment in colors red, yellow and blue. Mechanical tests were carried out on fresh pasta and hardened, as well as for the applied coating on masonry, so as to demonstrate the feasibility of the material. In addition, it verified the adequacy of the RDM built environment by means of thermal tests. The results demonstrated the feasibility of the proposed RDM with significantly higher values when compared to norms, especially the dash-added replacement content of 20% and addition of pigment in red. Therefore, the study shows the scientific community as an incentive to the use of technological innovations in construction, increasing the range of alternatives available for housing production, with the proposition of a material that achieves the desired functionality and obtain environmental gain, and may be adopted on construction sites as an alternative industrialized mortars.

Obtenção de triacetato de celulose a partir do bagaço de cana-deaçúcar para revestimento de micropartículas de goma gelana e avaliação do seu perfil de liberação in vitro e da mucoadesão ex vivo

Oral route of administration is considered to be the most comfortable, safe and greater adaptation for patients. But, oral route presents some disadvantages such as drugs bioavailability and side effects on the stomach. Some technologies are studied to soften and/or resolve these problems, such as coating with polymeric films, which are able to protect the pharmaceutical form of the acid stomachic environment and to act in the drug release, and mucoadhesive systems, which allow the pharmaceutical form remains a greater time interval in the intestine, increasing the effectiveness of the drug. Cellulose triacetate (CTA) films were produced from cellulose extracted from sugar cane bagasse. The films were prepared with different morphologies (with and without water, acting as non-solvent) and concentrations (3, 6.5 and 10%) of CTA and characterized using scanning electron microscopy (SEM), water vapor permeability (WVP), puncture resistance (PR), enzymatic digestion (DE), and mucoadhesive force evaluation (MF). Microscopy showed the formation of symmetric and asymmetric morphologies. WVP data showed that more concentrated films have higher values for WVP; moreover, asymmetric films had higher values than symmetric films. PR measurements showed that symmetric membranes are more resistant than asymmetric ones. More concentrated films were also more puncture resistant, except for symmetric membranes with CTA concentrations of 6.5 and 10% that did not show significant differences. All of the films presented large mucoadhesive capacities independent of their morphology and CTA concentration. From the results of WVP and RP, a symmetric filme with 6.5% CTA showed better ability and mechanical resistance, therefore, was selected to serve as coating of gellan gum (GG) particles incorporating ketoprofen (KET), which was confirmed by SEM. The selected film presented low values in measurements of the swelling index (SI) and in a dissolution test (DT). TGA analysis showed that the CTA coating does not influence the thermal stability of the particles and there is no incompatibility evidence between CTA, GG and KET. Coated particles released 100% of the ketoprofen in 24 h, while uncoated particles released the same amount in 4 h. The results of this study highlight the potential of CTA in the development of new controlled oral delivery systems.