Estudo da fadiga em liga de alumínio aeronáutico 7475-T761

This work will address the study of fatigue conditions with constant load in an alloy of aluminum analysis 7475 - T761, so we can better understand the conditions of the aircrafts which contain this alloy in their structures. A literature review, which was discussed the concepts of fracture mechanics, fatigue, aeronautical components, chemical analysis of aluminum alloys, fatigue problems that appears in the aircrafts, metallographic analysis, and testing of optical microscopy tensile, fatigue and microhardness, surface analysis (MEV) study of the chemical composition of the alloy in question, the main causes of crashes, was performed, completing the work, analysis of data from tensile test, hardness and fatigue together with the interpretation of images of optical microscopy and scanning electron was taken. The data indicated the high mechanical strength of the alloy, along with its microstructure indicating elongated grains and high surface contour, which shows such resistance by hindering the movement of dislocations. The grooves are clearly shown in the MEV images as well as the classic with increased fatigue loading and subsequent reduction of the number of cycles to rupture behavior shown in the graphs. Therefore we observed the optimal behavior is supported by the league when subjected to fatigue loadings

Reabilitação oral de paciente com sequela cirúrgica utilizando a técnica da zona neutra: relato de caso clínico

Objective and Case report: The purpose of this paper is to describe the neutral zone technique in a patient with oral deformity on the right labial commissure due to the resection of an oral cancer, enhancing the difficulty resulting from mouth limited opening and the use of tissue conditioner material to determine the neutral zone. Complete denture was obtained through this technique, providing good retention and stability which made functional rehabilitation feasible to patient of his or her masticatory function. Final considerations: The neutral zone technique in complete dentures will determine a specific intraoral area for tooth position and denture base contour where the forces generated by lips, cheeks and tongue are neutralized. The objective of this technique is to provide an alternative approach for patients who presented an historic instability of lower complete denture: atrophic ridge, oral deformities and also with disorder problems. An oral rehabilitation using this technique improves comfort to the patient providing retention and stability of mandibular complete dentures.

Correction of malpositioned implants through periodontal surgery and prosthetic rehabilitation using angled abutment

When dental implants are malpositioned in relation to the adjacent teeth and alveolar bone or in an excessive buccal or lingual position, the final prosthesis rehabilitation impairs the peri-implant health of the gingival tissues and the aesthetics of the patient. Thus, the purpose of this case was to report and discuss a multidisciplinary protocol for the treatment of a compromised maxillary tooth in a patient with an abscess in his right central incisor due to an excessive buccal implant position. The patient presented with an implant-supported provisional restoration on his right maxillary central incisor and a traumatic injury in his left central incisor. The treatment protocol consisted in (i) abutment substitution to compensate the incorrect angulation of the implant, (ii) clinical crown lengthening, (iii) atraumatic extraction of the left central incisor, and (iv) immediate implant placement. Finally, (v) a custom abutment was fabricated to obtain a harmonious gingival contour around the prosthetic crown. In conclusion, when implants are incorrectly positioned in relation to the adjacent teeth, associated with soft-tissue defects, the challenge to create a harmonious mucogingival contours may be achieved with an interdisciplinary approach and with the placement of an appropriate custom abutment.

Influência de variações das normas estéticas na atratividade do sorriso

The work presented here aims to evaluate how aesthetic norm variations influence the perception of attractiveness of a smile according to dentists and laymen. Methods: The smiles in photographs of a man and a woman were digitally changed. Eleven smiles were created for each one: an ideal, control smile - an ideal smile according to accepted norms - and 10 smiles containing individual variations of each of the following norms: a) 2mm and 3mm deviations from the middle line; b) the contour of the smile - contour of a straight smile and contour of a reverse smile; c) the angle of the lateral incisors - a mesial angle of 10° and a distal angle of 10°; d) 0.5mm and 1mm diastema; and e) dental proportion - Alber’s Proportion and Plato’s Proportion. The photographs were evaluated by two specialists in cosmetic dentistry and two laymen using the visual analogue scale. Results: The ideal smile for both genders was well accepted by both the specialists and the laymen. The opinions on the smiles with aesthetic variations varied, some were more positive than others, some were in agreement and some were in disagreement. Conclusion: The absence of deviations favors the perceived beauty of a smile, but some aesthetic variations seem to be better accepted than others. The success of aesthetic treatments depends on the active participation of dentists and patients in the planning stage.

Variação do canto de Thamnophilus Doliatus (Linnaeus, 1764) (Aves: Thamnophilidae) em diferentes regiões da América Latina

Pós-graduação em Ciências Biológicas (Zoologia) - IBB

Detecção de danos em estruturas guiadas usando ondas de alta frequência

Pós-graduação em Engenharia Mecânica - FEIS

Combinação de dispositivos de baixo custo para rastreamento de gestos

Pós-graduação em Ciência da Computação - IBILCE

Contorno aparente, envoltórias e equações diferenciais implícitas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sintomas de deficiências de macronutrientes em melancia

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Em busca de uma definição para o fenômeno do ouvido absoluto

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

How do laryngeal and respiratory functions contribute to differentiate actors/actresses and untrained voices?

Purpose. The present study aimed to compare actors/actresses's voices and vocally trained subjects through aerodynamic and electroglottographic (EGG) analyses. We hypothesized that glottal and breathing functions would reflect technical and physiological differences between vocally trained and untrained subjects.Methods. Forty participants with normal voices participated in this study (20 professional theater actors and 20 untrained participants). In each group, 10 male and 10 female subjects were assessed. All participants underwent aerodynamic and EGG assessment of voice. From the Phonatory Aerodynamic System, three protocols were used: comfortable sustained phonation with EGG, voice efficiency with EGG, and running speech. Contact quotient was calculated from EGG. All phonatory tasks were produced at three different loudness levels. Mean sound pressure level and fundamental frequency were also assessed. Univariate, multivariate, and correlation statistical analyses were performed.Results. Main differences between vocally trained and untrained participants were found in the following variables: mean sound pressure level, phonatory airflow, subglottic pressure, inspiratory airflow duration, inspiratory airflow, and inspiratory volume. These variables were greater for trained participants. Mean pitch was found to be lower for trained voices.Conclusions. The glottal source seemed to have a weak contribution when differentiating the training status in speaking voice. More prominent changes between vocally trained and untrained participants are demonstrated in respiratory-related variables. These findings may be related to better management of breathing function (better breath support).

Refinamento geométrico de contornos e cumeeiras de telhados de edifícios extraídos de dados laser com uso de imagem aérea

In this paper, a method is proposed to refine the LASER 3D roofs geometrically by using a high-resolution aerial image and Markov Random Field (MRF) models. In order to do so, a MRF description for grouping straight lines is developed, assuming that each projected side contour and ridge is topologically correct and that it is only necessary to improve its accuracy. Although the combination of laser data with data from image is most justified for refining roof contour, the structure of ridges can give greater robustness in the topological description of the roof structure. The MRF model is formulated based on relationships (length, proximity, and orientation) between the straight lines extracted from the image and projected polygon and also on retangularity and corner injunctions. The energy function associated with MRF is minimized by the genetic algorithm optimization method, resulting in the grouping of straight lines for each roof object. Finally, each grouping of straight lines is topologically reconstructed based on the topology of the corresponding LASER scanning polygon projected onto the image-space. The results obtained were satisfactory. This method was able to provide polygons roof refined buildings in which most of its contour sides and ridges were geometrically improved.

Lensometry by two-laser holography with photorefractive Bi12TiO20

Refractive and profilometric measurements of lenses were performed through holography with a photorefractive Bi12TiO20 crystal as the recording medium. Two properly aligned diode lasers emitting in the red region were employed as light sources. Both lasers were tuned in order to provide millimetric and sub-millimetric synthetic wavelengths. The surfaces of the test lens were covered by a 25-μm opaque plastic tape in order to allow the lens profilometry upon illuminating them with a collimated beam. The resulting holographic images appear covered by interference fringes corresponding to the wavefront geometry of the wave scattered by the lens. For refractive index measurement a diffusely scattering flat surface was positioned behind the uncovered lens which was also illuminated by a plane wave. The resulting contour interferogram describes the form of the wavefront after the beam traveled back and forth through the lens. The fringe quantitative evaluation was carried out through the four-stepping technique and the resulting phase map and the Branch-cut method was employed for phase unwrapping. The only non-optical procedure for lens characterization was the thickness measurement, made by a dial caliper. Exact ray tracing calculation was performed in order to establish a relation between the output wavefront geometry and the lens parameters like radii of curvature, thickness and refractive index. By quantitatively comparing the theoretical wavefront geometry with the experimental results relative uncertainties bellow 3% for refractive index and 1 % for focal length were obtained. © 2008 American Institute of Physics.

Visualisation and reconstruction in dentistry

Visualisation in the field of dentistry has nor, thus far, reached the same development as other medical fields. Potential applications of visualisation techniques in this area, however, are many, ranging from educational displays to training for delicate procedures. This paper reports on the investigation of techniques for handling three-dimensional models of teeth, aiming at investigation of dental structures. An algorithm was implemented for this purpose, which reconstructs three-dimensional teeth models from two-dimensional contour slices. Results employing various data sets are presented, including the output of VRML models for exploration.

Morphological aspects of tympanic bulla after ventral osteotomy in cats

To evaluate tympanic bulla healing after experimental ventral osteotomy in cats. Twenty adult cats were submitted to unilateral ventral bulla osteotomy and divided into two groups: cats of A1 group (n=10) were euthanized at 8 weeks and cats of A2 group (n=10), at 16 weeks postoperative. Signs of Horner's syndrome or damage to the inner ear were not found. Open-mouth radiographs taken in the immediate postoperative showed interruption in the contour of the larger compartment of the operated bulla. The result of Mcnemar'test was significant in A2 group (*p=0.0156). Macroscopic exams revealed that the operated bullae were similar to the normal ones, with preservation of the tympanic cavity. Connective tissue at the osteotomy site of the larger compartment was significantly found in the operated bullae in both groups (McNemar test: A1 p=0.0020*; A2 p=0.0078*). Histomorphometric analyses showed that the connective tissue length at the osteotomy site was shorter in A2 group than in the A1 group (Mann-Whitney test: p=0.0021*). Experimental ventral osteotomy did not alter significantly the tympanic bulla conformation and complete regeneration of tympanic bulla frequently did not occur before 16 weeks of postoperative period.