963 resultados para NYLON-1010
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The weight of a vehicle has always been considered an extreme important factor, because it interferes in the performance, steering, consume, environmental impact, wear of components, among the others. Because of the new demand, consume reduction aim and gases emission increased the necessity to manufacture lighter vehicles, guaranteeing the complying with the gas emission international law. Besides the legal demand, the low weight will certainly be essential for the competitiveness for the next generation of vehicles. It is with this thinking the composite materials have been introduced in the automobilist industry, because those materials show an excellent relation of strength/weight, providing a reduction of consume and the increase of load capacity. Those factors justify the increase of interest of industry and the necessity of optimization of those materials and of their process. For this research, the field of application will be the Baja SAE Project, a project that is fully developed by engineering students, where they build a prototype single seat, off-road category, for use on hilly slopes with obstacle. This research aims to study two key components of the prototype are made of composite materials, analyzing all the processing. In addition, there is the analysis of the viability of this production parts to a Baja SAE vehicle, in order to increase their performance and reduce their weight without reducing the safety and robustness of the prototype. It was possible to achieve weight reduction of the steering subsystem with manufacturing the flywheel hybrid composite (carbon/glass) and the replacement of SAE 1010 steel by hybrid composite (carbon/aramid) in CVT box. The importance of this study is to obtain a good project for the vehicle of technical and scientific manner, contributing to the know-how to the team and providing a basis for optimization for upcoming projects
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The present study aims to compare three types of internal fixation for fractures of the mandibular angle. Mechanical testing was performed on replicas of polyurethane hemimandibles sectioned at the angle region to simulate a fracture and fixed with three different hardwares. Fixation devices enrolled on this survey included the grid plates with and without an intermediate bar and the method described by Champy and colleagues in 1978 and the sample consisted of 10 hemimandibles for each group. Vertical loadings were applied on each hemimandible and recorded after a vertical displacement of 3 and 5 mm. Statistical analysis was made by means of the variance analysis (ANOVA) and the Duncan test with a significance level of 5%. The Champy technique showed a statistically significant increased resistance when compared to the grid plates after vertical displacements of 3 and 5 mm. The results of this survey suggest that the Champy technique, when compared to the grid plate positioned at the middle of the mandibular bone (placement site selected for this study), is more resistant than the grid plate and that the inclusion or not of an intermediate bar to the grid plates does not improve its resistance after linear vertical loadings.
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Background This multicentre study aimed to investigate long-term radiographic and functional results following the treatment of condylar fractures using an angulated screwdriver system and open rigid internal fixation with an intraoral surgical approach. Methods Twenty-nine patients with a total of 32 condylar fractures were evaluated. The patients were investigated prospectively based on the following variables: age, sex, aetiology, side, location and classification of the fracture, degree of displacement, associated fractures, surgical approach, oral health status, type of osteosynthesis plate, duration of surgery, mouth-opening, complications, and duration of follow-up. Results The fractures were classified as subcondylar (n = 25) or condylar neck (n = 7). Mean patient age was 36.38 ± 16.60 years. The median duration of postoperative follow-up was 24.39 ± 13.94 months. No joint noise, weakness of the facial nerve, joint pain, or muscle pain was observed. An additional retromandibular approach was necessary to enable the treatment of one subcondylar fracture with medial displacement. Conclusion Subcondylar or condylar neck fractures with medial or lateral displacement can be treated using an intraoral approach with satisfactory results with the advantages of the absence of visible scarring, the avoidance of facial nerve injury, and the ability to obtain rapid access to the fracture.
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Introduction: Currently, there are many questions regarding the cleaning methods seeking greater efficiency and less loss of burs. Aim: the aim of this study was to evaluate the influence of cleaning methods on the cutting efficiency and morphological characteristics of stainless steel burs tungsten carbide (carbide). Materials and method: Thirty burs were divided into five groups (n = 5) according with the cleaning method: L1 - steel brush, L2 - nylon brush, L3 - ultrasound + distilled water, L4 - ultrasound + descaling solution and L5 - no cleaning method (control). The burs were used for the cutting of bovine enamel during six periods of 12 minutes each. After each period, the burs were cleaned (except L5 ) following the protocol established for each group. The cutting efficiency was determined by mass loss and morphological characteristics. Result: The average amount of wear after 72 minutes of use were L1 = 0.3558 g; L2 = 0.4275 g; L3 = 0.4652 g; L4 = 0.4396 g e L5 = 0.4854 g; significant differences in the time of use (p < 0.001) and cleaning method (p < 0.001). The L1 group showed the worst performance. Regardless of the experimental group, morphological analysis revealed alterations in the cutting blades soon after the first 12 minutes, being L1 the most affected group. Conclusion: The cleaning with wire brush was the most damaging method to the cutting efficiency and to the morphology of carbide burs.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Background: This multicentre study aimed to investigate long-term radiographic and functional results following the treatment of condylar fractures using an angulated screwdriver system and open rigid internal fixation with an intraoral surgical approach.Methods: Twenty-nine patients with a total of 32 condylar fractures were evaluated. The patients were investigated prospectively based on the following variables: age, sex, aetiology, side, location and classification of the fracture, degree of displacement, associated fractures, surgical approach, oral health status, type of osteosynthesis plate, duration of surgery, mouth-opening, complications, and duration of follow-up.Results: The fractures were classified as subcondylar (n = 25) or condylar neck (n = 7). Mean patient age was 36.38 +/- 16.60 years. The median duration of postoperative follow-up was 24.39 +/- 13.94 months. No joint noise, weakness of the facial nerve, joint pain, or muscle pain was observed. An additional retromandibular approach was necessary to enable the treatment of one subcondylar fracture with medial displacement.Conclusion: Subcondylar or condylar neck fractures with medial or lateral displacement can be treated using an intraoral approach with satisfactory results with the advantages of the absence of visible scarring, the avoidance of facial nerve injury, and the ability to obtain rapid access to the fracture. (C) 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Profile enhancement most frequently involves mentoplasty. For this purpose, the author performs conchal grafts to the chin. A total of 28 women aged 15 to 76 years (mean age, 38.11 ± 15.11 years) requested mentoplasty by itself or combined with rhinoplasty, rhytidoplasty, or submental lipoplasty. The conchal cartilage was harvested subperichondrally through a posterior 3-cm incision. The specimen measured 3 x 1 cm, which was sufficient to project the chin 2 to 3 mm. For 4 to 5 mm of projection, both cartilages were used. The graft was positioned under the periosteum and held with two 5-0 nylon sutures. In these cases, the conchal cartilage graft was a suitable option for chin augmentations up to 5 mm.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Cats are gradually occupying a more important position as pets and this preference is a result of how easy cat maintenance in an urban environment is, even though they are very prolific and need surgical sterilization. This paper aims at evaluating obtained data within 15 years of research in a university service program that offers free cats sterilization surgery. We carried out a statistical analysis of data shown in the records of animals treated by the program. Surgical sterilization was performed on 647 animals (409 females – 63% and 238 males – 37%). Unilateral cryptorchidism was observed in 9 (3.8%) male cats. Forty (10%) female cats were pregnant at the time of the surgery and the treatment with contraceptives was observed in 67 (16.4%) female cats. One death occurred during anesthesia recovery and 2 cats were euthanized because of wound infection, totalizing an amount of 0.5% of severe complications. From 1996 to 2004, 212 female cats were spayed (122 adults and 90 prepubertal) and during that time two different approaches for ovariohysterectomy were compared: flank laparotomy and ventral midline celiotomy. The flank laparotomy approach was used in only 46 female cats (21.7%) due to some disadvantages observed – the need of an incision on each flank in prepubertal or nulliparous animals and the difficulty or impossibility of total uterus removal. In the same period, 105 male cats underwent orchiectomy via an open technique in which the spermatic cord was linked with nylon thread. From 2005 to 2010, 197 females (106 adults and 91 prepubertal) were spayed. The minilaparotomy technique was used to perform ovariohysterectomy on 139 female cats (70.6%). In this procedure, ovaries and uterus were exteriorized in a blind fashion with a hook through a small midline incision. The traditional midline ovariohysterectomy, which incision length permits direct visualization of the ovaries and uterus, had to be performed in 58 (29.4%) female cats due to advanced pregnancy, full urinary bladder during surgery or obesity. Over the past 6 years, 133 male cats (48 adults and 85 prepubertal) were castrated by means of an open technique in which the spermatic cord was tied to itself. The demand for surgeries during the project demonstrated that people are becoming aware concerning the importance of sterilization when facing cat overpopulation and abandonment.
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The aim of the present study was to evaluate the postoperative complications of bicoronal flaps used to treat facial fractures. One hundred and thirty two patients that received bicoronal flaps for the treatment of upper and middle third facial fractures were called for clinical and radiographic examination. Minimum follow-up was 1 year and all patients had charts with adequate information about their perioperative care pertinent to the study. Results showed as complications hypoesthesia (17%), partial unilateral frontal motor deficit (11%), infection (3%), hypertrophic scars (3%), varying degrees of alopecia (18%), seroma or hematoma in the immediate postoperative period (5%). The flap provided wide surgical access to the upper and middle facial thirds with very few serious complications, most frequently allowing good aesthetic results.
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The aim of the present study was to investigate the effect of isofl avones supplementation of a fermented soy product on its sensory acceptance, physicochemical properties and probiotic cell viable count. Additionally we also investigated the ability of the mixed starter cultures (Enterococcus faecium CRL 183 and Lactobacillus helveticus 416) to modify the isofl avones profi le of soy product during the fermentation process. Three products were analysed: soy product fermented with E. faecium CRL 183 and L. helveticus 416, isofl avonessupplemented soy product (fermented with E. faecium CRL 183 and L. helveticus 416; 50mg/100g, Isofl avin®, Galena, Brazil) and unfermented soy product. A panel of judges evaluated the acceptability of the samples on a nine point structured hedonic scale. The chemical composition namely fat, protein, ash and total carbohydrate contents, pH, enumeration of viable Lactobacillus spp. and Enterococcus spp. and quantifi cation of isofl avones using HPLC were investigated. All determinations were conducted after 7 days storage at 10°C. The sensorial acceptance was reduced in the isofl avones-supplemented soy product, but this effect was not signifi cant compared to the sample without isofl avones addition. Chemical composition did not differ (p<0.05) among the samples. Cell viable counts were reduced and total fermentation time was longer in the isofl avonessupplemented soy product, suggesting that the isofl avone addition could inhibit the starter cultures. However, all the products may be considered probiotic since they exhibited lactic acid bacterial populations varying from 2.3 x 109 up to 1.22 x 1010 CFU/mL. Fermentation of soymilk did not change the isofl avones profi le. In conclusion, it was possible to obtain a fermented soy product containing a high isofl avones concentration, adequate sensory and chemical characteristics and lactic acid bacterial viability suffi ciently high to characterize the product as a probiotic. The mixed starter culture was not able to convert the glycoside isofl avones into aglycone or produce equol during the fermented soy product processing.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)