Effect of the parafunctional occlusal loading and crown height on stress distribution

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

Influence of crown-to-implant ratio, retention system, restorative material, and occlusal loading on stress concentrations in single short implants

Purpose: The aim of this study was to assess the contributions of some prosthetic parameters such as crown-to-implant (C/I) ratio, retention system, restorative material, and occlusal loading on stress concentrations within a single posterior crown supported by a short implant. Materials and Methods: Computer-aided design software was used to create 32 finite element models of an atrophic posterior partially edentulous mandible with a single external-hexagon implant (5 mm wide × 7 mm long) in the first molar region. Finite element analysis software with a convergence analysis of 5% to mesh refinement was used to evaluate the effects of C/I ratio (1:1; 1.5:1; 2:1, or 2.5:1), prosthetic retention system (cemented or screwed), and restorative material (metal-ceramic or all ceramic). The crowns were loaded with simulated normal or traumatic occlusal forces. The maximum principal stress (σmax) for cortical and cancellous bone and von Mises stress (σvM) for the implant and abutment screw were computed and analyzed. The percent contribution of each variable to the stress concentration was calculated from the sum of squares analysis. Results: Traumatic occlusion and a high C/I ratio increased stress concentrations. The C/I ratio was responsible for 11.45% of the total stress in the cortical bone, whereas occlusal loading contributed 70.92% to the total stress in the implant. The retention system contributed 0.91% of the total stress in the cortical bone. The restorative material was responsible for only 0.09% of the total stress in the cancellous bone. Conclusion: Occlusal loading was the most important stress concentration factor in the finite element model of a single posterior crown supported by a short implant.

Arte reversa: aplicando a engenharia reversa na arte

This study aimed to examine the reverse engineering and respond to a concern about the possible application of this concept in art, breaking down barriers and breaking paradigms. Using 3D scanning, the art of computer aided design and manufacturing – CAD/CAM, machining by computer numerical control - CNC, engineering, and applying this methodology in the arts especially in sculpture, it is possible to dematerialize a artwork, virtualizes it in 3D programs, make speeches, and process a new work, a new art elsewhere. By the example of surgeries at a distance, the artist, or technical author could produce their works, and materialize them anywhere. In other words, do the reverse gear. It discusses the relationship between art and technology, the role of the author, the viewer, which can interfere with the interactivity that case by stating that art, exists only in the look and feel of the viewer.

A utilização das tecnologias assistidas por computador como elemento de integração, pesquisa e desenvolvimento nas disciplinas de projeto para a engenharia e design

The use of technologies called computedassisted, such as CAD - (Computed Aided Design), CAM - (Computed Aided Manufacturing) and CNC - (Computed Numerical Control), increasingly demanded by the market, are needed in the teaching of subjects technical drawing and design courses for engineering and design. However its use findl barriers in the more conservative wing of the academy, who advocate the use of traditional drawing, for the settling of the concepts and the development of spatial reasoning. This study aimed to show the results obtained with the design and production of an apparatus for measuring a three-dimensional computer-aided milling machine, interaction, integration and consolidation of concepts, fully demonstrating that the learning of computer-assisted technology is possible, and its use is most appropriate, meaningful and productive, than the use of instruments in the classic design.

Sanitário solar: a transdisciplinaridade como ferramenta de projeto, design e desenvolvimento sustentável

The appropriate use of computer aided technologies, allied to the concepts and design guidelines, grounded in biology, stimulated the development of a solar toilet, able to convert human waste into compost, rich in nutrients for use in gardens, farms and small farms. This transdisciplinary approach is presented as a necessary tool to be used in academia, integrating and developing activities previously disconnected. The solar toilet also called green bathroom, combines the most modern concepts and technologies of computer-aided design, design, selection of materials and microbiological control, reaching biologically correct and safe composting of waste, ensuring the viability of the project terms of cost, deployment, use and environmental safety, such as supporting sustainable development. It is also planned to install a pilot project in a small community with the aim of assessing its implementation and use as a complementary activity and university extension.

Difusão de tecnologia CAD e CNC como ferramenta básica de criação e produção em pequena escala, acessível à comunidade

The high competitiveness and the search for newtechnologies that differentiate the product from the project,require the use of new digital tools. The computer aideddesign - Computed Aided Design (CAD), with electronicmodeling, simulation, structural analysis and production,performed in a virtual environment through the applicationof specific software, are available but their use is stilllimited. There are various software available in languagesand extensions to industrial production which, from 3Dmodeling, they can manage through Computer NumericalControl - Computed Numerical Control (CNC) machiningcenters, laminating, stamping, mold making and otherprocesses productive. This project aims to encouragecreativity and entrepreneurship in the community throughthe provision of technology computer aided design - CAD,with a view to implementation of machining technology.

Concepção, modelagem, simulação e usinagem de um aerofólio automotivo auxiliado por computador

With the advancement of computer technology and the availability of technology computer aided design (CAD) errors in the designs are getting smaller. To this end the project aims to assess the reliability of the machine (CNC), which was designed by students of mechanical engineering college engineering - UNESP Bauru, by designing, modeling, simulation and machining an airfoil automotive. The profile template selected for the study will be a NACA 0012 machined plates in medium density fiberboard (MDF) and will be performed with a structural analysis simulation using finite elements and a software CFD (Computational Fluid Dynamics), and test the real scale model in a wind tunnel. The results obtained in the wind tunnel and CFD software will be compared to see the error in the machining process.

Aplicação de ferramentas BIM em um projeto de cobertura do estádio Professor Dário Rodrigues Leite

In all segments, the companies are looking for the highest productivity with the lowest possible cost, and in the construction industry, the thinking is the same. Over time, techniques that generate more productivity supplanted previous techniques; an example is the CAD technology that replaced free drawings in projects execution. However, the Computer Aided Design (CAD) technology does not deal with certain factors that permeate the entire project. It is required the use of other techniques to supply this need in traditional projects. For example, a software for schedule management, another for assets management and a person who makes calculations for estimates and budgets. The BIM (Building Information Modeling) technology aims to integrate all this information, facilitating the communication among members of a work team and reducing the time required to carry out the project. This work is a applied research, a descriptive research, carried out through modeling and simulation, processes inherent in the use of BIM, a survey was also used only to contextualization. BIM was used for a soccer stadium roof project, in order to verify the feasibility of such use through the analysis of: BIM tools, difficulties encountered and implications of BIM use, and comparison of traditional methods and the use of BIM. To aid the contextualization, a survey was conducted to verify the use of BIM in medium and small companies

Implementação de CADD nos cursos de graduação em engenharia mecânica

This study aims to demonstrate the importance of computer-aided design and drafting (CADD) software for mechanical engineers. In addition, evaluate the software: Inventor 2015, Creo 3.0 and Solid Edge ST8, developed by consolidate companies in the market. In order to accomplish those goals, software application and its advantages will be demonstrated for the industry and for the academia. The evaluation process consists in modeling two mechanical assemblies, in order to compare functional aspects among the software. At the end, it is concluded that the learning of CADD software is of great importance also is the basis for using Computer-aided Engineering (CAE) and Computer-Aided Manufacturing (CAM) tools. Furthermore, it is suggested that Inventor and Solid Edge are more likely to be used in the academia

Population structure and stock assessment of Hoplias malabaricus (Characiformes: Erythrinidae) caught by artisanal fishermen in river-reservoir transition area in Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Two-way regionalized classification of multivariate datasets and its application to the assessment of hydrodynamic dispersion

Zones of mixing between shallow groundwaters of different composition were unravelled by two-way regionalized classification, a technique based on correspondence analysis (CA), cluster analysis (ClA) and discriminant analysis (DA), aided by gridding, map-overlay and contouring tools. The shallow groundwaters are from a granitoid plutonite in the Funda o region (central Portugal). Correspondence analysis detected three natural clusters in the working dataset: 1, weathering; 2, domestic effluents; 3, fertilizers. Cluster analysis set an alternative distribution of the samples by the three clusters. Group memberships obtained by correspondence analysis and by cluster analysis were optimized by discriminant analysis, gridded memberships as follows: codes 1, 2 or 3 were used when classification by correspondence analysis and cluster analysis produced the same results; code 0 when the grid node was first assigned to cluster 1 and then to cluster 2 or vice versa (mixing between weathering and effluents); code 4 in the other cases (mixing between agriculture and the other influences). Code-3 areas were systematically surrounded by code-4 areas, an observation attributed to hydrodynamic dispersion. Accordingly, the extent of code-4 areas in two orthogonal directions was assumed proportional to the longitudinal and transverse dispersivities of local soils. The results (0.7-16.8 and 0.4-4.3 m, respectively) are acceptable at the macroscopic scale. The ratios between longitudinal and transverse dispersivities (1.2-11.1) are also in agreement with results obtained by other studies.

Computer-assisted analysis of cell proliferation markers in oral lesions

Abnormalities in any component of the cell cycle regulatory machine may result in oral. cancer, and markers of cell proliferation have been used to determine the prognosis of tumor progression. The aim of this study was to determine whether silver-stained nucleolar organizer region (AgNOR) and Ki-67 measurements could improve the assessment of growth rates in oral lesions. Eighty-three oral biopsies were studied, 20 of which were classified as fibrous inflammatory hyperplasia (FIH), 40 as leukoplakia (LKP) and 23 as oral. squamous cell carcinoma (OSCC). Within the LKP group, 22 out of 29 biopsies were diagnosed as non-dysplastic leukoplakia (LK) and 18 as dysplastic teukoptakia (DLK), presenting discrete, moderate and severe dysplasia. Ki-67 immunotabeting of the lesions increased steadily in the following order: FIH, DLK, LK and OSCC, indicating that Ki-67 is a good marker for predicting the protiferative fraction among benign, premalignant and malignant oral lesions. The median values of AgNOR parameters indicate that the morphometric index gives better results regarding the proliferative rate than the numerical one. A series of linear regressions between AgNOR parameters and Ki-67 showed positive associations. We conclude that a combination of Ki-67 and morphometric AgNOR analyses could be used as an aid in the determination of the protiferative status of oral epithelial. cells in oral cancer. (C) 2007 Elsevier GmbH. All rights reserved.

Accuracy assessment of a photogrammetric close-range reconstruction system

Geometric accuracy of a close-range photogrammetric system is assessed in this paper considering surface reconstruction with structured light as its main purpose. The system is based on an off-the-shelf digital camera and a pattern projector. The mathematical model for reconstruction is based on the parametric equation of the projected straight line combined with collinearity equations. A sequential approach for system calibration was developed and is presented. Results obtained from real data are also presented and discussed. Experiments with real data using a prototype have indicated 0.5mm of accuracy in height determination and 0.2mm in the XY plane considering an application where the object was 1630mm distant from the camera.

A lung computed tomographic assessment of positive end-expiratory pressure-induced lung overdistension

The aim of this study was to assess positive end-expiratory pressure (PEEP)-induced lung overdistension and alveolar recruitment in six patients with acute lung injury (ALI) using a computed tomographic (CT) scan method. Lung overdistension was first determined in six healthy volunteers in whom CT sections were obtained at FRC and at TLC with a positive airway pressure of 30 cm H2O. In patients, lung volumes were quantified by the analysis of the frequency distribution of CT numbers on the entire lung at zero end-expiratory pressure (ZEEP) and PEEP. In healthy volunteers at FRC, the distribution of the density histograms was monophasic with a peak at -791 ± 12 Hounsfield units (HU). The lowest CT number observed was -912 HU. At TLC, lung volume increased by 79 ± 35% and the peak CT number decreased to -886 ± 26 HU. More than 70% of the increase in lung volume was located below -900 HU, suggesting that this value can be considered as the threshold separating normal aeration from overdistension. In patients with ALI, at ZEEP the distribution of density histograms was either monophasic (n = 3) or biphasic (n = 3). The mean CT number was -319 ± 34 HU. At PEEP 13 ± 3 cm H2O, lung volume increased by 47 ± 19% whereas mean CT number decreased to -538 ± 171 HU. PEEP induced a mean alveolar recruitment of 320 ± 160 ml and a mean lung overdistension of 238 ± 320 ml. In conclusion, overdistended lung parenchyma of healthy volunteers is characterized by a CT number below -900 HU. This threshold can be used in patients with ALI for differentiating PEEP-induced alveolar recruitment from lung overdistension.