979 resultados para ceramic cutting tool
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ABSTRACTObjective:to analyze the implementation of a trauma registry in a university teaching hospital delivering care under the unified health system (SUS), and its ability to identify points for improvement in the quality of care provided.Methods:the data collection group comprised students from medicine and nursing courses who were holders of FAPESP scholarships (technical training 1) or otherwise, overseen by the coordinators of the project. The itreg (ECO Sistemas-RJ/SBAIT) software was used as the database tool. Several quality "filters" were proposed to select those cases for review in the quality control process.Results:data for 1344 trauma patients were input to the itreg database between March and November 2014. Around 87.0% of cases were blunt trauma patients, 59.6% had RTS>7.0 and 67% ISS<9. Full records were available for 292 cases, which were selected for review in the quality program. The auditing filters most frequently registered were laparotomy four hours after admission and drainage of acute subdural hematomas four hours after admission. Several points for improvement were flagged, such as control of overtriage of patients, the need to reduce the number of negative imaging exams, the development of protocols for achieving central venous access, and management of major TBI.Conclusion: the trauma registry provides a clear picture of the points to be improved in trauma patient care, however, there are specific peculiarities for implementing this tool in the Brazilian milieu.
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Objective: To develop and validate an instrument for measuring the acquisition of technical skills in conducting operations of increasing difficulty for use in General Surgery Residency (GSR) programs. Methods: we built a surgical skills assessment tool containing 11 operations in increasing levels of difficulty. For instrument validation we used the face validaity method. Through an electronic survey tool (Survey MonKey(r)) we sent a questionnaire to Full and Emeritus members of the Brazilian College of Surgeons - CBC - all bearers of the CBC Specialist Title. Results: Of the 307 questionnaires sent we received 100 responses. For the analysis of the data collected we used the Cronbach's alpha test. We observed that, in general, the overall alpha presented with values near or greater than 0.70, meaning good consistency to assess their points of interest. Conclusion: The evaluation instrument built was validated and can be used as a method of assessment of technical skill acquisition in the General Surgery Residency programs in Brazil.
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The dewatering of iron ore concentrates requires large capacity in addition to producing a cake with low moisture content. Such large processes are commonly energy intensive and means to lower the specific energy consumption are needed. Ceramic capillary action disc filters incorporate a novel filter medium enabling the harnessing of capillary action, which results in decreased energy consumption in comparison to traditional filtration technologies. As another benefit, the filter medium is mechanically and chemically more durable than, for example, filter cloths and can, thus, withstand harsh operating conditions and possible regeneration better than other types of filter media. In iron ore dewatering, the regeneration of the filter medium is done through a combination of several techniques: (1) backwashing, (2) ultrasonic cleaning, and (3) acid regeneration. Although it is commonly acknowledged that the filter medium is affected by slurry particles and extraneous compounds, published research, especially in the field of dewatering of mineral concentrates, is scarce. Whereas the regenerative effect of backwashing and ultrasound are more or less mechanical, regeneration with acids is based on chemistry. The chemistry behind the acid regeneration is, naturally, dissolution. The dissolution of iron oxide particles has been extensively studied over several decades but those studies may not necessarily be directly applicable in the regeneration of the filter medium which has undergone interactions with the slurry components. The aim of this thesis was to investigate if free particle dissolution indeed correlates with the regeneration of the filter medium. For this purpose, both free particle dissolution and dissolution of surface adhered particles were studied. The focus was on acidic dissolution of iron oxide particles and on the study of the ceramic filter medium used in the dewatering of iron ore concentrates. The free particle dissolution experiments show that the solubility of synthetic fine grained iron oxide particles in oxalic acid could be explained through linear models accounting for the effects of temperature and acid concentration, whereas the dissolution of a natural magnetite is not so easily explained by such models. In addition, the kinetic experiments performed both support and contradict the work of previous authors: the suitable kinetic model here supports previous research suggesting solid state reduction to be the reaction mechanism of hematite dissolution but the formation of a stable iron oxalate is not supported by the results of this research. Several other dissolution mechanisms have also been suggested for iron oxide dissolution in oxalic acid, indicating that the details of oxalate promoted reductive dissolution are not yet agreed and, in this respect, this research offers added value to the community. The results of the regeneration experiments with the ceramic filter media show that oxalic acid is highly effective in removing iron oxide particles from the surface of the filter medium. The dissolution of those particles did not, however, exhibit the expected behaviour, i.e. complete dissolution. The results of this thesis show that although the regeneration of the ceramic filter medium with acids incorporates the dissolution of slurry particles from the surface of the filter medium, the regeneration cannot be assessed purely based upon free particle dissolution. A steady state, dependent on temperature and on the acid concentration, was observed in the dissolution of particles from the surface even though the limit of solubility of free iron oxide particles had not been reached. Both the regeneration capacity and efficiency, with regards to the removal of iron oxide particles, was found to be temperature dependent, but was not affected by the acid concentration. This observation further suggests that the removal of the surface adhered particles does not follow the dissolution of free particles, which do exhibit a dependency on the acid concentration. In addition, changes in the permeability and in the pore structure of the filter medium were still observed after the bulk concentration of dissolved iron had reached a steady state. Consequently, the regeneration of the filter medium continued after the dissolution of particles from the surface had ceased. This observation suggests that internal changes take place at the final stages of regeneration. The regeneration process could, in theory, be divided into two, possibly overlapping, stages: (1) dissolution of surface-adhered particles, and (2) dissolution of extraneous compounds from within the pore structure. In addition to the fundamental knowledge generated during this thesis, tools to assess the effects of parameters on the regeneration of the ceramic filter medium are needed. It has become clear that the same tools used to estimate the dissolution of free particles cannot be used to estimate the regeneration of a filter medium unless only a robust characterisation of the order of regeneration efficiency is needed.
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Pumping systems account for over 20 % of all electricity consumption in European industry. Optimization and correct design of such systems is important and there is a reasonable amount of unrealized energy saving potential in old pumping systems. The energy efficiency and therefore also the energy consumption of a pumping system heavily depends on the correct dimensioning and selection of devices. In this work, a graphical optimization tool for pumping systems is developed in Matlab programming language. The tool selects optimal pump, electrical motor and frequency converter for existing pumping process and calculates the life cycle costs of the whole system. The tool could be used as an aid when choosing the machinery and to analyze the energy consumption of existing systems. Results given by the tool are compared to the results of laboratory tests. The selection of pump and motor works reasonably well, but the frequency converter selection still needs development
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Since poisoning by Senecio spp. is one of the main causes of cattle death in southern Brazil, control of these plants is a priority for the local livestock production. After the pasture has been mowed, grazing by 16 sheep was efficient for controlling Senecio brasiliensis and Senecio madagascariensis populations in a 5.5-hectare area that had long been severely infested with these species. A total of 28,629 plants among S. brasiliensis (flower-of-souls, 10,122) and S.madagascariensis (fireweed, 18,507) were almost completely eliminated in a two-year period. The number of sheep was kept at 3.0 stock units/ha, but a variable number of cattle were temporarily stocked according to pasture availability. The major sanitary practice applied to the sheep was anthelmintic administration. Liver biopsies taken from sheep and cattle before and after experimental period didn't reveal any change associable with seneciosis. The performance levels of the sheep were comparable to those observed in flocks managed under traditional extensive grazing systems in southern Brazil.
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Tutkimuksen tavoitteena on kuvailla tarinankerrontaa brändin rakennuksen välineenä, ja selvittää mitkä ovat tarinankerronnan erityispiirteet sosiaalisessa mediassa. Aikaisempien teorioiden ja julkaisujen avulla kootaan viitekehys joka osoittaa käsitteiden vaikutukset toisiinsa. Tutkimus osoittaa tarinankerronnan vaikuttavan vahvistavasti kaikkiin brändipääoman ulottuvuuksiin, lähinnä tunteita herättävien ja muistettavuutta lisäävien ominaisuuksiensa ansiosta. Empiirisessä osiossa selvitetään laadullisen sisällönanalyysin keinoin kuinka yleistä brändien tarinankerronta tällä hetkellä on, ja kuvaillaan millaisia tarinoita yritykset kertovat. Aineisto koostuu sadan suosituimman brändin Facebookissa jakamista videomuotoisista tarinoista. Tutkimus osoitti, että brändien tarinankerronta sosiaalisessa mediassa on toistaiseksi melko vähäistä. Tarinat voidaan luokitella kirjallisuudesta tuttujen tarinatyyppien mukaisesti. Suurin osa brändien esittämistä tarinoista pyrkii synnyttämään yleisössä ihailun ja nostalgian tunteita, mutta useat tarinat myös sisältävät humoristisia piirteitä.
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Bronchoalveolar lavage (BAL) is a procedure that retrieves cells and other elements from the lungs for evaluation, which helps in the diagnosis of pulmonary diseases. The aim of this study was to perform this procedure for cellular analysis of BAL fluid alterations during experimental infection with Aelurostrongylus abstrusus in cats. Fourteen cats were individually inoculated with 800 third stage larvae of A. abstrusus and five non-infected cats lined as a control group. The BAL procedure was performed through the use of an endotracheal tube on the nineteen cats with a mean age of 18 months, on 0, 30, 60, 90, 120, 180 and 270 days after infection. Absolute cell counts in the infected cats revealed that alveolar macrophages and eosinophils were the predominant cells following infection. This study shows that the technique allows us to retrieve cells and first stage larvae what provides information about the inflammatory process caused by aelurostrongylosis.
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Paremmin lastuttavia M-käsiteltyjä teräksiä on käytetty yrityksissä jo yli 20 vuoden ajan. Ominaisuuksiensa ansiosta M-teräksillä on pystytty pienentämään koneistuskustannuksia ja parantamaan kilpailukykyä. Viime vuosien aikana lastuavat terät ja työstökoneet ovat kuitenkin kehittyneet ja ero M-terästen ja tavanomaisten terästen välillä on voinut kaventua. Tämän diplomityön tavoitteena oli tutkia, saavutetaanko M-teräksen käytöllä taloudellisia etuja nykyaikaisissa konepajaolosuhteissa. Tutkimuksessa vertailtiin M-käsitellyn ja tavanomaisen 42CrMo4 – teräksen koneistusta. Valmistuskokeissa tarkasteltiin terien kulumista, lastun muotoa ja pinnanlaatua. Koekappaleena toimi olakkeellinen kuusiomutteri M64 kierteellä. Tuotteita valmistettiin yli 500 kappaletta ja materiaalia poistettiin noin 2000 kg. Koetulosten perusteella tuotteille laskettiin koneistuskustannukset kuvitteellisessa yrityksessä. Ero materiaalien välillä oli suurin työvaiheissa, joissa lastuaminen oli jatkuvaa. Sisä- ja ulkosorvauksessa M-käsiteltyä terästä lastunneiden terien kestoikä oli noin kaksinkertainen ja kierteen sorvauksessa noin nelinkertainen tavalliseen teräkseen verrattuna. Hakkaavassa työstössä terien kestoikä oli molemmilla materiaaleilla sama. Työssä suoritettujen kokeiden ja kustannuslaskelmien perusteella, käyttämällä M-käsiteltyä terästä voidaan pienentää valmistuskustannuksia. Materiaalien välinen ero korostuu, kun hakkaavaa työstöä on vähän, sarjat ovat suuria ja tuotanto on miehittämätöntä.
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The aim of this work is to evaluate the mechanism of stock removal and the ground surface quality of advanced ceramics machined by a surface grinding process using diamond grinding wheels. The analysis of the grinding performance was done regarding the cutting surface wear behavior of the grinding wheel for ceramic workpieces. The ground surface was evaluated using Scanning Electron Microscopy (SEM). As a result it can be said that the mechanism of material removal in the grinding of ceramic is largely one of brittle fracture. The increase of the h max can reduce the tangential force required by the process. Although, it results in an increase in the surface damage, reducing the mechanical properties of the ground component.
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In the last decade a lot has been discussed about the suitability of using cutting fluid in abundance to cool and lubricate machining processes. The use of cutting fluid generally causes economy of tools and it becomes easier to keep tight tolerances and to maintain workpiece surface properties without damages. In the other hand, it brings also some problems, like fluid residuals and human diseases. Because of them some alternatives has been sought to minimise or even avoid the use of cutting fluid in machining operations. Some of these alternatives are dry cutting and cutting with minimum quantity of fluid (MQF). The main goal of this work is to discuss these tendencies. Therefore, topics like kinds and methods of applications of modern cutting fluids and what are new in this area will unavoidably be considered. MQF and dry cutting techniques, their applications and where it is not possible to apply them will also be focused. To exemplify the topics, this work will describe some of the researches been developed in two important Brazilian Universities: State University of Campinas (UNICAMP) and Federal University of Uberlândia (UFU).
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Process planning is a very important industrial activity, since it determines how a part or a product is manufactured. Process planning decisions include machine selection, tool selection, and cutting conditions determination, and thus it is a complex activity. In the presence of unstable demand, flexibility has become a very important characteristic of today's successful industries, for which Flexible Manufacturing Systems (FMSs) have been proposed as a solution. However, we believe that FMS control software is not flexible enough to adapt to different manufacturing system conditions aiming at increasing the system's efficiency. One means to overcome this limitation is to include pre-planned alternatives in the process plan; then planning decisions are made by the control system in real time to select the most appropriate alternative according to the conditions of the shop floor. Some of the advantages of this approach reported in the literature are the reduction of the number of tool setups, and the selection of a replacement machine for executing an operation. To verify whether the presence of alternatives in process plans actually increases the efficiency of the manufacturing system, an investigation was carried out using simulation and design of experiments techniques for alternative plans on a single machine. The proposed methodology and the results are discussed within this paper.
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In this report are described means for indoor localization in special, challenging circum-stances in marine industry. The work has been carried out in MARIN project, where a tool based on mobile augmented reality technologies for marine industry is developed. The tool can be used for various inspection and documentation tasks and it is aimed for improving the efficiency in design and construction work by offering the possibility to visualize the newest 3D-CAD model in real environment. Indoor localization is needed to support the system in initialization of the accurate camera pose calculation and auto-matically finding the right location in the 3D-CAD model. The suitability of each indoor localization method to the specific environment and circumstances is evaluated.
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