Comparação da adaptação cervical de estruturas metálicas para metalo-cerâmica obtidas através de técnica de fundição rápida e convencional, utilizando três revestimentos comerciais

Pós-graduação em Odontologia - FOA

Efeito de um revestimento com processamento rápido para fundição de titânio na camada de reação, porosidade interna, fluidez, rugosidade superficial e adaptação marginal de Copings

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O efeito da técnica de inclusão para fundição de titânio CP na fluidez, rusogidade, camada de reação e desajuste marginal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da concentração do líquido especial e da temperatura do molde de revestimentos na desadaptação marginal de coroas fundidas em titânio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da temperatura final do ciclo de aquecimento do revestimento na fluidez e na resistência à tração do Ti c.p. e da liga Ti-6AI-4V

Pós-graduação em Reabilitação Oral - FOAR

Influência do método de aquecimento de revestimentos fosfatados sobre sua resistência à compressão e sobre a rugosidade de superfície e estabilidade dimensional de ligas de Ni-Cr e Ni-Cr-Ti

Pós-graduação em Odontologia - FOA

Reação exotérmica e expansões de presa e térmica de revestimentos frente às técnicas de fundição convencional e rápida

Pós-graduação em Odontologia - FOA

Feeding, body condition and reproductive investment of Astyanax intermedius (Characiformes, Characidae) in relation to rainfall and temperature in a Brazilian Atlantic Forest stream

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A simulação de Monte Carlo como instrumento fundamental para a análise de viabilidade econômica: a implementação de uma fundição de ferro em uma empresa metalúrgica

In uncertainly economic scenarios, an economic feasibility analysis must be done to accept a project based on investment criteria, such as NPV and IRR, mainly because the shareholders tend to invest their budget in a project if it has a great chance to return their investments. The studied company outsources all of its foundry services, what makes it very dependent of its suppliers, because the products have a lower quality level, long delivery periods and high prices. Therefore, this work will analyze the project of building an iron-casting foundry to decrease the dependence of its suppliers. In order to develop this research, all needed data related to the construction of the foundry and sales were collected to create deterministic and probabilistic (Monte Carlo Simulation) cash flows using MsExcel® and Oracle's Crystal Ball® software. As a result, the project was found to be risky by the NPV and IRR in the case of this new production line supplying only the internal needs. However, when the company offers its services to the foundry market, the project turns to be feasible

Estudo sobre fornos de tratamento térmico e propostas de cogeração de energia em usina siderurgica não integrada

Steel industry is a sector heavily dependent on energy, both electrical and thermal. Since the receipt of raw materials to the shipment of finished products to customers, through mergers, casting, rolling, heat treatment, inspection, among others, high amounts of energy are demanded, generating very significant costs to the productive chain in its entirety . Therefore, any alternative that favors the reduction in energy consumption or barateie the cost of this is very welcome. Within this context, this paper aims to make a technical and economic analysis of installing a cogeneration plant in the field rolling in a non-integrated steel mill. Two configurations are proposed plants, with one being the use of heat from waste gases from furnaces existing in the area mentioned and another with the use of heat from waste gases from an internal combustion engine. Both proposals are evaluated technically and later is done the economic analysis, calculating the financial return (pay back) in relation to the investment required, operation and maintenance of the plant

Investment theory and empirical approach: a discussion on dificulties

In this paper, we analyse several contributions made concerning investment theory in the last decades. The objective of the paper is to discuss the difficulties of the testable theory identified by Chirinko (1983), Fazzari et al. (1988, 2000), Kaplan and Zingales (1997) and Hubbard (1998) to better understand the results of empirical approach. These few authors we worked with provided theoretical arguments and empirical evidences that internal finance variable of the firms may work as an indicator of financial constraint. In several developed countries, financing constraints has been identified as important to understand the investment spending. The principal indicator of financing constraints, that is, cash-flow has been questioned. However, the evidences offer a support to its relevance. We try to justify such evidence based on the few authors listed above, which have been quoted by empirical works. We try to contribute to debate adding aspect of the corporate finance to offer a logical explanation to econometric difficulties.

Multicollinearity and financial constraint in investment decisions: a bayesian generalized ridge regression

This paper addresses the investment decisions considering the presence of financial constraints of 373 large Brazilian firms from 1997 to 2004, using panel data. A Bayesian econometric model was used considering ridge regression for multicollinearity problems among the variables in the model. Prior distributions are assumed for the parameters, classifying the model into random or fixed effects. We used a Bayesian approach to estimate the parameters, considering normal and Student t distributions for the error and assumed that the initial values for the lagged dependent variable are not fixed, but generated by a random process. The recursive predictive density criterion was used for model comparisons. Twenty models were tested and the results indicated that multicollinearity does influence the value of the estimated parameters. Controlling for capital intensity, financial constraints are found to be more important for capital-intensive firms, probably due to their lower profitability indexes, higher fixed costs and higher degree of property diversification.

Influence of heat treatment and mechanical cycling on hardness and fracture analysis of Ti35Nb5Zr casting alloy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microstructural, physical, and fluid dynamic assessment of spinel-based and phosphate-bonded investments for dental applications

This work reports the experimental evaluation of physical and gas permeation parameters of four spinel-based investments developed with or without inclusion of sacrificial fillers. Data were compared with those of three commercial formulations. Airflow tests were conducted from 27 to 546°C, and permeability coefficients were fitted from Forchheimer's equation. Skeletal densities found for spinel- (ρs = 3635 ± 165 kg/m3) and phosphate-bonded (ρs = 2686 ± 11 kg/m3) samples were in agreement with the literature. The developed investments were more porous and less permeable than commercial brands, and the differences were ascribed to the different pore morphologies and hydraulic pore sizes of ceramic matrices. The inclusion of both fibers and microbeads resulted in increases of total porosity (42.6–56.6%) and of Darcian permeability coefficient k1 (0.76 × 10−14–7.03 × 10−14 m2). Air permeation was hindered by increasing flow temperatures, and the effect was related to the influence of gas viscosity on ΔP, in accordance with Darcy's law. Casting quality with molten titanium (CP Ti) was directly proportional to the permeability level of the spinel-based investments. However, the high reactivity of the silica-based investment RP and the formation of α-case during casting hindered the benefits of the highest permeability level of this commercial brand.

The fitness of copings constructed over UCLA abutments and the implant, constructed by different techniques: casting and casting with laser welding

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)