A perda anual de ovelhas em criações de sistema extensivo apresenta altos níveis na região Sul do Brasil. Na Serra Gaúcha essa porcentagem chega a 30% e torna-se um fator alarmante para propriedades com sistemas de produção de carne, leite e lã. As perdas reprodutivas em ovinos desta região estão relacionadas com a baixa taxa de concepção do rebanho e alta mortalidade perinatal de cordeiros (MPC) e frequentemente esses fatores são decorrentes de enfermidades, deficiências nutricionais durante o período gestacional e pós-parto ou por manejo inadequado de ovelhas e cordeiros. A MPC, definida como a morte de recém-nascidos imediatamente antes ou durante o parto e até os primeiros vinte e oito dias de vida é uma das principais causas de baixa taxa de desmame no Rio Grande do Sul (RS). Sua etiologia envolve ações complexas que circundam a ação individual e a interação de muitos fatores relacionados entre si. Estudos sobre as causas de MPC no RS têm apontado o complexo exposição/inanição e hipotermia, além da distocia como as duas principais patologias envolvidas nesses óbitos. Condições ambientais adversas, como o frio severo, também causam a morte em consequência da falta de adaptação do recém-nascido às novas condições de vida. A busca de informações que venham a elucidar as causas dessas perdas motivou a realização do presente estudo e o uso da esquila durante a gestação foi utilizado como uma possível ferramenta para minimizar a MPC. O efeito da esquila préparto (74 dias de gestação) sobre sobre o perfil metabólico e produtivo de ovelhas e no peso e desenvolvimento de seus cordeiros durante o primeiro mês de vida foram avaliados neste estudo. Um rebanho de 40 ovelhas gestantes da raça Corriedale foi dividido aleatoriamente em dois grupos: ovelhas com esquila completa (EC) e ovelhas mantidas com velo ou ovelhas controle (OC). As ovelhas e seus respectivos cordeiros foram avaliados em três momentos distintos durante o experimento: no parto, entre 15 e 21 dias de lactação e entre 22 e 45 dias de lactação. Os parâmetros de escore de condição corporal, dosagem de beta-hidroxibutirato, hematócrito, hemoglobina, lactato, glicose, peso corporal, peso da placenta e produção do leite foram mensurados e correlacionados. Os valores médios de hematócrito, hemoglobina e peso dos cordeiros apresentaram diferenças significativas (p< 0,05) entre os grupos EC e OC. O peso médio da placenta e a produção de leite apontaram diferença significativa enquanto que os achados para escore de condição corporal (ECC) e beta-hidroxibutirato não evidenciaram diferenças entre os grupos EC e OC, considerando todos os períodos em conjunto (p> 0,05). A produção leiteira de ovelhas do grupo EC (1.261,25 mL/dia) foi maior (p <0,05) do que no grupo OC (937,79 mL/dia). A esquila de ovelhas aos 74 dias de gestação mostrou-se como importante ferramenta para o melhor desenvolvimento de cordeiros na fase pós-nascimento de forma a contribuir para a diminuição da taxa de mortalidade perinatal. / The annual loss of sheep in extensive system has expressive levels in southern Brazil. It can reach 30% in some areas and becomes an alarming factor for properties with systems producing meat, milk and wool. Reproductive losses in sheep in this region are related to low conception rate of the herd and a high lamb perinatal mortality (LPM). Often these factors are due to diseases, nutritional deficiencies during pregnancy and postpartum period or inadequate management of ewes and lambs. Perinatal mortality is defined as lambs in the death of the neonate until the first twenty-eight days. The LPM is responsible for the low rate of weaning in Rio Grande do Sul (RS), southern Brazil. Its etiology involves complex actions and interaction of many factors related to each other. Studies about causes of the LPM in RS have showed the complex exposure, hypothermia and starvation, in addition to dystocia as the two main pathologies involved in these deaths. Adverse environmental conditions, such as severe cold, cause death due to the lack of adaptation of the newborn to the new living conditions also. The search for more information that might elucidate the causes of these losses motivated the present study and the use of shearing during pregnancy has been used as a possible tool to minimize LPM. The effect of pre-partum shearing (74 days gestation) on the metabolic and productive profile and weight of ewes and their lambs develop during the first month of life were studied. A flock of 40 pregnant Corriedale ewes were randomly divided into 2 groups: ewes completely sheared (EC) and ewes maintained with fleece or sheep control (OC). The ewes and their lambs were evaluated at three different times during the experiment: at birth, between 15 and 21 days of lactation and between 22 and 45 days of lactation. The parameters such as body condition score, betahydroxybutyrate, PVC, hemoglobin, lactate, glucose, body weight, placental weight and milk production were measured and correlated. The mean values of PVC, hemoglobin and lambs weight showed significant differences (p <0.05) between the EC and OC groups. The average weight of placenta and milk production showed a significant difference while the findings for body condition score (ECC) and beta-hydroxybutyrate showed no differences between groups EC and OC, considering all periods together (p> 0.05). Milk production of ewes of group EC (1261.25 mL / day) was higher (p < 0.05) than in the OC group (937.79 mL / day). Shearing of sheep at 74 days of pregnancy was a important tool for the better development of lambs in the post-birth in order to contribute to reducing the rate of perinatal mortality.

Este trabalho buscou analisar dois materiais para fabricação de navalhas para corte de sucata, de forma a identificar aquele que melhor atenda às solicitações de desgaste dentro de um custo competitivo. Foram realizados testes comparativos de desempenho entre navalhas de aço AISI S1 e SAE 4340, sendo este último o material base utilizado atualmente para a fabricação de navalhas para corte de sucata na Gerdau Aços Especiais Charqueadas. O estudo foi realizado durante o processamento de sucata em uma Prensa Tesoura Harris BSH 1123, sendo que as medições de desgaste foram realizadas nas arestas de corte com a utilização de um relógio comparador. Os resultados mostram que o aço ferramenta, apesar de seu elevado custo e necessidade de maior controle durante o tratamento térmico, é superior em todos os aspectos, apresentando a metade do desgaste do aço ligado quando utilizado nas mesmas condições e trazendo benefícios operacionais como a redução do tempo de troca das navalhas, sendo o material mais indicado para este fim. / Performance trials were carried out to identify the most suitable material for the manufacturing of blades for scrap cutting considering resistance for wear specifications as well as competitive cost. The materials tested were AISI S1 and SAE 4340, being the latter the material currently used for this application at Gerdau Aços Especiais Charqueadas. The study was conducted during scrap processing in a Harris BSH 1123 shearing press. In order to measure the cutting edge wear, a dial gauge was employed. The results show that the tool steel, despite its higher cost and more complex heat treatment process, is superior for all analyzed aspects, presenting less than half of the wear shown by the low alloyed steel when processing scrap under the same conditions. Other additional operational benefits also were obtained as a decrease in the set up time, being the material of choice for this task.

Research in local fracture processes and micro-machining of polymers and polymer-based composites has attracted increasing attention, in development of composite materials and miniaturisation of polymer components. In this thesis, sectioning (machining) of a glassy polymer and a carbon nanotube based composite at the nanoscale was performed by an instrumented ultramicrotome. The yield stresses and fracture toughness of these materials were determined by analysing the sectioning forces. Fractographic analysis by atomic force microscopy was conducted to characterise the topographies and elastic properties of the sectioned surfaces to explore the deformation and fracture behaviour of the polymer during nanosectioning. The study reveals that a transition from homogenous to shear localised deformation occurred as the uncut chip thickness (depth of cut) or sectioning speed increased to a critical value. Analytical and finite element methods were used to model the nanosectioning process. The shear localised deformation was caused by thermal softening due to plastic dissipation. Although not considering sectioning, the tensile properties of a polymer nanocomposite were additionally investigated, where the degree of nanofibrillation and polyethylene glycol (PEG) content had significant effects.

The thesis deals with the design of a technological process for the production a rotationally symmetrical component, which is part of the body for the chassis ball joint of a passenger car. Thesis was developed on request and in cooperation with THK RHYTHM Automotive Czech a.s. On the basis of a literary study, a technological process consisting of 10 operations was designed and elaborated. For the prototype production of the component, a four-column hydraulic press SHPFS 250, with a nominal force 2500 kN, was selected and price offer were prepared. For each of ten operations a prototype tool was designed and prepared assembly drawings. To reduce costs, a single die set was designed to allow all tools to be clamped. The total cost of acquisition of the prototype hydraulic press and tools was set at CZK 2,672,950.

This thesis presents a tool design for production of embossments into the bottom part of the agricultural silo made of Dx51D material. The research analysis all technologies used for embossing, that is cutting and shallow drawing. This is followed by a chapter on simulation. The tool design itself is described. Its principle is based on tools for punching machines. The upper half of the tool is composed of a weldment to be clamped into pressing machine, into which are mounted functional parts in the form of inserts. The lower tool consists of several bolted plates, punches and a holding plate, which is located on the springs. In order to achieve correct design, necessary calculations were carried out and it was all confirmed by simulation in ANSYS. The two tool halfs are guided by pins attached at the edges of the lower tool. The technical - economical evaluation compares the work of the proposed tool with other possibilities of embossing.

This master’s thesis presents a proposal for the technology of manufacturing sheet metal part, which is a part of a bicycle wall bracket. The component is made of steel sheet ČSN 11 325 with subsequent surface treatment by galvanizing. Due to the chosen method of manufacturing with a progressive stamping die, the research part is focused on the technology of shearing and bending. Technological calculations were performed for the most suitable production variant, on the basis of which a mechanical press ANDRITZ Metals with the designation KSTU 2000-20-4G-PSE was chosen. Furthermore, the design of the tool itself is presented, which is substantiated by drawing documentation. At the end of the work, a technical and economic evaluation of the produced series of 300 000 workpieces per year is calculated.

The thesis proposes a concept of manufacturing the folding meter lock. The part is made from DC01+LC steel of 0,3 mm thickness. The series size is 100 000 pcs/year. A forming in a progressive combination tool combining shearing, bending and stamping was chosen for the production, based on the analysis of possible solutions. The tool, designed on the basis of literary research of used technologies, produces the part in eleven steps exerting maximal force of 38,5 kN. The production will take place on an eccentric press LEN 40 C. The market price of 3,38 Kč for one piece was established by the technical and economic evaluation.

This thesis deal with stress control of frame of crushing mill of grain with the aim of defining and consequent optimalization of undersized and overlarge parts of the construction. This frame is screwed assembly. Control is static analysis of frame. This analysis use Finite Element Method.

The project presents design of technology production of the hinge made of metal sheet plate 11 321. The variant proposed solutions have been designed manufacturing cutting and bending technology in transfer combined die. These themes were elaborated in literatures studies. As a working machine was selected eccentric press LEN 40 C of Slovak producer TOMA INDUSTRIES s.r.o., Trnava, with a nominal force 400 kN. Functional parts are made of tool steel 19 436. In economic results was defined cost of one piece including manufacturers profit and the break-even point, which is coming after production of 151 966 pieces.

The project, which was done within the scope of engineering’s study shows the proposal of new technology and production organization of a part “PC cover” – a piece done by deep drawing technology from steel sheet of material 11 321. The study shows some of production operations such as cutting, bending, drawing and shearing, included production method solving. In the project were solved also necessary technological calculations and constructional drafts of forming tool. The whole work covers a complex solution of problems related to production of PC cover together with technological disposition of workplace which represents effective layout, distribution and designing of workplace and machines, used for production of the part in a workshop