Interface microstructure of alumina mechanically metallized with Ti brazed to Fe–Ni–Co using different fillers

NASCIMENTO,R.M. et al.Interface microstructure of alumina mechanically metallized with Ti brazed to Fe–Ni–Co using different fillers. Materials Science and Engineering A, v.466, n.1/2, p. 195-200, 2007.

The Effect of Residence Time on the Tensile Properties of Superelastic and Thermal Activated Ni-Ti Orthodontic Wires

Since the 1980s, different devices based on superelastic alloys have been developed to fulfill orthodontic applications. Particularly in the last decades several researches have been carried out to evaluate the mechanical behavior of Ni-Ti alloys, including their tensile, torsion and fatigue properties. However, studies regarding the dependence of elastic properties on residence time of Ni-Ti wires in the oral cavity are scarce. Such approach is essential since metallic alloys are submitted to mechanical stresses during orthodontic treatment as well as pH and temperature fluctuations. The goal of the present contribution is to provide elastic stress-strain results to guide the orthodontic choice between martensitic thermal activated and austenitic superelastic Ni-Ti alloys. From the point of view of an orthodontist, the selection of appropriate materials and the correct maintenance of the orthodontic apparatus are essential needs during clinical treatment. The present work evaluated the elastic behavior of Ni-Ti alloy wires with diameters varying from 0.014 to 0.020 inches, submitted to hysteresis tensile tests with 8% strain. Tensile tests were performed after periods of use of 1, 2 and 3 months in the oral cavity of patients submitted to orthodontic treatment. The results from the hysteresis tests allowed to exam the strain range covered by isostress lines upon loading and unloading, as well as the residual strain after unloading for both superelastic and thermal activated Ni-Ti wires. Superelastic Ni-Ti wires exhibited higher load isostress values compared to thermal activated wires. It was found that such differences in the load isostress values can increase with increasing residence time.

Práticas da ti verde que contribuem para o desenvolvimento sustentável: um estudo de caso em indústrias do RN

This dissertation aims to describe the practices of Information Technology Green contributing to sustainable development, in computers and textile industries in the state of Rio Grande do Norte. The goal is to understand the importance and contribution of IT Green for sustainable development. The research methodology used involved a survey of the theoretical approach prepared, involving two case studies in industries of Rio Grande do Norte. The analysis was supported by an analysis of content, which allowed the understanding of the phenomenon of the Information Technology Green sustainable development in the case studies. In conclusion, is that the Green Information Technology contributes to sustainable development, even so through incipient aspects that highlight the competitive business with a focus on cost reduction, and efforts in sustainable practices

Mudança dos processos de negócios e adequação da TI nas empresas em decorrência da implantação do sistema público de escrituração digital SPED: um estudo de casos múltiplos

Companies have always been organized by processes, often imperceptible to its employees. With the advancement of technology, organizational processes currently run an organization through computers, and thus generate immediate information that is available to each sector. With the objective of seeking business information in real time, the government created the SPED - Public System of Digital, which involves three subsystems, which are the Electronic Invoice, Digital Accounting Bookkeeping and Digital Tax Bookkeeping. This system is revolutionizing the business structures when gathering, in an innovative way, all information and interlinked business processes. For the implementation of SPED, a revision in the organizational processes is required, since the information is generated and is sent online to the government, without mistakes. Thus the study aimed to analyze the change brought about by the implementation of the Public System of Digital SPED in the main business processes. In order to do so, we have performed a multiple case study involving three companies in the state of Para, two operate in wholesale and one explores agribusiness. The Data collection was performed by accounting professionals, IT and managers. According to the results obtained, it was found that in two companies, the IT infrastructure was capable of deploying the new system without major problems, while one company had more difficulties to cope with the new system. However, all companies had to examine its processes to make the customizations needed to fit. It was also observed that there is no IT Governance in two companies. Therefore, we recommend the use of an appropriate model, not only for the implementation of SPED, but as a way to manage and extract better results from investment in information technology

Influência do número de refundições da liga Ni-Cr-Mo-Ti sobre as propriedades de próteses metalocerâmicas

A frequently encountered difficulty in oral prosthetics is associated with the loss of metallic alloys during the melting stage of the production of metal-ceramic replacement systems. Remelting such materials could impar their use in oral rehabilitation due to loss in esthetics, as well as in the chemical, physical, electrochemical and mechanical properties. Nowadays, the Ni-Cr-Mo-Ti alloy is widely used in metal-ceramic systems. Manufacturers state that this material can be remelted without significant alterations in its behavior, however little has been established as to the changes in the performance of this alloy after successive remelting, which is common practice in oral prosthetics. Therefore, the objective of this study was to evaluate possible changes in the esthetics and associated properties of metalceramic samples consisting of Ni-Cr-Mo-Ti and dental porcelain. Three to five remelting steps were carried out. The results revealed that Ni-Cr-Mo-Ti can be safely used even after three remelting steps. Further remelting significantly affect the characteristics of the alloys and should not be recommended for the manufacture of metal-ceramic systems