<p>In the last decades, high speed cutting has become an attractive technology in the wood industry. The possibility of reducing global costs in addiction with an increase in productivity, were the main reasons for the enlargement of the use of this technology. </p><p>As usual, these advantages are accompanied by disadvantages that should be carefully analyzed. If on the one hand cutting forces are reduced with increasing cutting speeds, on the other hand, the centrifugal forces affecting the tool are higher. Exposed to such high loads, there is a considerable risk of tool failure that embeds hazards for both machine and workers. </p><p>To prevent the risk of accidents and to guarantee safety in use, security standards have been implemented in industrial fields, imposing specific experimental tests, with defined procedure modes. Accordingly with these standards, the results obtained through the tests should fall inside limited ranges. The experimental tests suggested on the European Standards are intended to simulate the real working conditions of a rotating cutting tool, where extreme centrifugal forces are imposed by the high values of speed. Although their main importance, these destructive tests aren’t always practicable. It happens, for instance, with tools produced in small batch sizes, or as an ascertainment for the fail-critical speed during the development stage, or even due to physical incompatibilities between the tool and the laboratory testmachines. </p><p>The high value of weight associated with the cutting tool prototype developed and patented by Verktygs Larsson AB was an impediment to run the laboratorial tests specified by the standards, forcing the company to find a new way to assure the safety requirements of their product. </p><p>The main goal of this project was the development of an alternative method based on finite element theory to perform a safety analysis to the prototype of a wood cutter. This tool is used as a component in high speed planers. </p><p>In addiction to this primary objective, some considerations were made about other available models, with increased dimensions or even with different parameters. If there was the need, design changes could be assumed in order to guarantee that the tool reached the requisites of the safety standards. Considering an optimization effort, material changes would also be considered, to aim in the direction of reducing the tool weight and the consequent centrifugal forces.</p>

In the last decades, high speed cutting has become an attractive technology in the wood industry. The possibility of reducing global costs in addiction with an increase in productivity, were the main reasons for the enlargement of the use of this technology. As usual, these advantages are accompanied by disadvantages that should be carefully analyzed. If on the one hand cutting forces are reduced with increasing cutting speeds, on the other hand, the centrifugal forces affecting the tool are higher. Exposed to such high loads, there is a considerable risk of tool failure that embeds hazards for both machine and workers. To prevent the risk of accidents and to guarantee safety in use, security standards have been implemented in industrial fields, imposing specific experimental tests, with defined procedure modes. Accordingly with these standards, the results obtained through the tests should fall inside limited ranges. The experimental tests suggested on the European Standards are intended to simulate the real working conditions of a rotating cutting tool, where extreme centrifugal forces are imposed by the high values of speed. Although their main importance, these destructive tests aren’t always practicable. It happens, for instance, with tools produced in small batch sizes, or as an ascertainment for the fail-critical speed during the development stage, or even due to physical incompatibilities between the tool and the laboratory testmachines. The high value of weight associated with the cutting tool prototype developed and patented by Verktygs Larsson AB was an impediment to run the laboratorial tests specified by the standards, forcing the company to find a new way to assure the safety requirements of their product. The main goal of this project was the development of an alternative method based on finite element theory to perform a safety analysis to the prototype of a wood cutter. This tool is used as a component in high speed planers. In addiction to this primary objective, some considerations were made about other available models, with increased dimensions or even with different parameters. If there was the need, design changes could be assumed in order to guarantee that the tool reached the requisites of the safety standards. Considering an optimization effort, material changes would also be considered, to aim in the direction of reducing the tool weight and the consequent centrifugal forces.

The most common cause for revision total hip replacement surgey is aseptic loosening of the acetabular component. This thesis explores the effect of three techniques to improve the depth and quality of cemented acetabular component fixation in primary total hip replacement. This may have beneficial effects on the longevity of cemented acetabular components and reduce the rate of revision surgery for aseptic loosening. Aims: 1. Determine the effect of the rim cutter on cement pressure during cup insertion. 2. Examine the effect of the rim cutter on cement penetration distance. 3. Evaluate the effect of bone grafting of the acetabular notch. 4. Determine the effect of iliac suction during cement pressurisation. 5. Compare the behaviour of bone cement with Play Dough. Materials and Methods: 1. Sawbones hemi pelvis models were fitted with pressure transducers at the rim and apex of the acetabulum. Peak pressure was measured upon insertion of cups with different flange sizes and when the acetabulum was prepared with the rim cutter. 2. Foam cavities were used to measure the depth of cement penetration when the same cups and rim cutter were used. 3. Hemi pelvis models were modified to simulate bone grafting of the acetabular notch. Again, pressure sensors were mounted at the apex and rim of the acetabulum. Intra-acetabular cement pressure was compared with native acetabulae. 4. A back bleeding model of the acetabulum was fitted with a suction catheter. The effect on cement penetration into cancellous bone was measured compared with no suction. 5. Play Dough pressurisation and penetration into hemi pelvises and foam was compared to bone cement. Results: 1. Significant increase in peak apex and rim pressures when flanged cup inserted into an acetabulum prepared with the rim cutter compared with both flanged and unflanged cups alone. 2. Significant increase in cement penetration at the rim of the acetabulum when rim cutter used and flanged cup inserted when compared with flanged and unflanged cups alone. 3. Significant increase in intra-acetabular pressure when cement pressurised in presence of simulated acetabular notch bone grafting compared with normal acetabulae. 4. Significant increase in cement penetration distance when suction used compared with no suction. 5. Significant differences in the flow characteristics between bone cement and Play Dough. Conclusion: The authors recommend preparation of the acetabular rim with the rim cutter and bone grafting of the acetabular notch to improve the depth and uniformity of the cement mantle in cemented primary THA. Play Dough at room temperature is not a suitable substitute for bone cement in in-vitro cementing studies.

Made available in DSpace on 2015-03-26T13:30:50Z (GMT). No. of bitstreams: 1 texto completo.pdf: 843146 bytes, checksum: 7b89b9c0374c84a12c9df88c213f038e (MD5) Previous issue date: 2014-02-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The leaf-cutting ants are considered pests in the Brazilian economy because they cause big losses in the agricultural and forestry systems. Annually, large sums are spent seeking their control, which is done primarily through available insecticides. Their use is under heavy pressure of national and international certification due to the need to protect the environment because the current active ingredients available in the commercial insecticide formulations are not considered safe to the environment. The behavioral repertoire displayed by the ants is responsible for the difficulty in achieving ant control. Among the main behaviors performed by worker ants there are the autogrooming , allogrooming , trophallaxis and waste handling, which are responsible for maintaining the colony hygiene keeping it free of parasites and pathogens. The insecticide fipronil cause neural effects leading the individuals to death by hyperactivity, impairing key behavioral traits important for the colony maintenance. In this work, the workers were expose to fipronil by two ways: spraying and toxic baits. In the first, fipronil was sprayed in the soil where six colonies of Acromyrmex subterraneus subterraneus were placed. In the second, three grams of toxic bait were offered to five colonies to A. subterraneus subterraneus. The frequency of occurrence of the main behaviors was recorded. Under insect sprayed in soil, ant behaviors like autogrooming , disposal of adults and waste handling were reduced in colonies. Under toxic bait exposure, the ant behaviors of autogrooming , allogrooming , waste removal, and activities undertaken within the fungus garden by the minors workers were reduced resulting in the development of parasitc fungus Escovopsis present in the fungus garden of the colonies. Thus the two forms of the insecticide application have effects on workers of A. subterraneus subterraneus, however the baits have a more pronounced effect in the colonies and colony suppressed was achieved by affecting mainly minor workers. Since these workers are responsible for maintaining the symbiotic fungus, its absence culminates in the decay and death of the fungus garden and subsequent death of workers due to lack of food substrate, occurring, finally the complete suppression of colony. / As formigas-cortadeiras são consideradas pragas de grande importância na economia brasileira por causarem grandes perdas nos setores agrícolas e florestais. Anualmente grandes somas são gastas buscando seu controle, que é feito principalmente através de produtos sintéticos disponíveis no mercado. Alguns deles encontram-se sob forte pressão das certificadoras nacionais e internacionais devido à necessidade de proteção dos ecossistemas, pois seus princípios ativos não são considerados adequados ao ambiente. O repertório comportamental apresentado pelas formigas é um dos responsáveis pela dificuldade encontrada em seu controle. Entre os principais comportamentos executados pelas formigas operárias encontra-se o autogrooming , allogrooming , trofalaxia e manipulação do lixo que são responsáveis pela manutenção da higiene da colônia, mantendo-a fora da ação de parasitas e patógenos. O inseticida fipronil é causador de efeitos no sistema nervoso podendo comprometer os indivíduos expostos e suprimir a colônia. Neste trabalho as operárias entraram em contato com o inseticida fipronil por duas vias: pulverização de solução de fipronil e iscas formicidas. No primeiro, aspergiu-se uma concentração subletal do inseticida fipronil no solo onde foram colocadas seis colônias de Acromyrmex subterraneus subterraneus. No segundo três gramas de iscas formicidas foram oferecidas a cinco colônias de A. subterraneus subterraneus. Os principais comportamentos executados foram medidos através da frequência de acontecimento. Os comportamentos de autogrooming , descarte de adultos e a manipulação do lixo foram menores em colônias tratadas com o inseticida do que nas colônias testemunhas quando o inseticida foi pulverizado. Já com as iscas, os comportamentos de autogrooming , allogrooming , remoção de lixo, e atividades realizadas dentro do jardim de fungo pelas jardineiras foram reduzidos o que propiciou o aumento no desenvolvimento do fungo parasita Escovopsis presente no jardim de fungo das colônias. Assim, as duas formas de aplicação do inseticida possuem efeitos nas operárias de A. subterraneus subterraneus, no entanto, as iscas possuem um efeito mais pronunciado nas colônias e operárias dessa espécie e foram letais às operárias jardineiras. Uma vez que essas operárias são responsáveis pela manutenção do fungo simbionte, sua ausência culmina no decaimento e morte do jardim de fungo e posterior morte das operárias por falta de substrato alimentar, ocorrendo por fim a supressão completa da colônia.

Made available in DSpace on 2016-12-08T16:44:32Z (GMT). No. of bitstreams: 1 PGPV07MA019.pdf: 983013 bytes, checksum: af67f91f15946eb87d559e480ef2fc06 (MD5) Previous issue date: 2007-12-12 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The increasing of insect epidemics in the agro-ecosystem is due to ecologucal perturbations like reduction in biodiversity and improverishment of soils. Ant s species of the genus Acromyrmex and Atta can become importante pest, requiring frequente interventions for their control, usually done by toxicant baits that presente side effects. In this work, it was studied the management of the leaf cutter ants through out techniques of low cost and less environmental impact by using homeopathic/phytoterapic preparations. Etiological data, sepcies assessment and ethnic considerations were evaluated as well. Theresearch work was carried out in the Planalto Serrano /catarinense region. The effectiveness of homeopathic/phytoterapic preparations was evaluated in field conditions. For that, two independente experiments in randomized blocks design were installed considering block as local effect. The treatments forAcromyrmrx ants were: triturated ant nosode, triturade fungus colony nosode, softened of ant s nosode, softned fungus colony nosode, homeopathy Belladonna, homeopathic water, nem bait, sesame bait, placebo, and without intervention. For the experimente with Atta ants, the treatments were: triturated and nosode, softned ant nosode, homeopathy Belladonna, homeopathic water, nem bait, sesame bait, placebo, and without intervention. All the homeopathic preparations were applied in the thirtieth centesimal hahnemanniana dilution (30CH), made accordingto Farmacopéia Homeopática Brrasileira (1977). The phytoterapy baits were obtained by the mixture of wheat flour, flour of sesame or neem oil and water, in the proportion 2:2:1. Placebo baits were made by wheat flour and water. The identification of species of leaf cutter ants was done from 60 anthills of the genus Acromyrmex and 40 anthills of the genus Atta. Ethnology studies were from three anthills of both genus, Atta and Acromyrmex. Observations of beavior forage preference were taken along the year, in one day per month for each two hours during a period of 24 hours. The ethno-entomology studies were done through out a qualitative and quantitative questionnaire applied to Family farms regarding the man s perceptions in diferente production systems, organic, in transition, and conventional systems. The questions approached the characteristics of the production system; period in the activity; identification and knowledge on natural methods of control among others. The analysis of data showed that the phytoterapy baits, and the homeopathic preparations reduced the total acrivities and forage acrtivity of Acromyrmex and Atta as well. The total and forage activities were vairable during the year, for both genus Atta and Acromyrmex, being dependente of the temperature conditions and relative humidity of the air. The taxonomiv studies revealed that in the genus Acromyrmex the most frequente species were Acromyrmex laticeps, Acromyrmex heyeri, Acromyrmex. A. coronata and A. lundi are considered species rare in this region. The genus Atta presented the specie Atta sexdens piriventris. According to tyhe farmers interviewees the ants represent importante cause of damages to the crops and their control has been made mostly by toxicant baits. The homeopathic preparations showed importante tool for the control to both genus of leaf cutter ants. The best bait was homeopathic preparation based on ants. Neem Baits and sesame bait affected also the behavior on both genus of leaf cutter ants / A proliferação epidêmica de insetos no agroecossistema é sintoma de desequilíbrio, associado à redução da biodiversidade e empobrecimento dos solos. Formigas dos gêneros Acromyrmex spp. e Atta spp. podem se tornar importantes pragas, requerendo intervenções freqüentes, normalmente realizadas por iscas tóxicas de alto poder residual. Neste trabalho estudou-se o controle de formigas cortadeiras, através de técnicas de baixo custo e impacto ambiental pela utilização de preparados homeopáticos e iscas fitoterápicas. Adicionalmente, coletaram-se dados etológicos, identificação de espécies ocorrentes e considerações étnicas em propriedades familiares da região do Planalto Serrano Catarinense. A eficácia dos preparados homeopáticos e fitoterápicos foram avaliadas a campo em dois experimentos independentes, delineamento em blocos ao acaso, separados por tempo e local. Os tratamentos para o experimento com formigas Acromyrmex spp. foram: nosódio triturado de formigas, nosódio triturado do cultivo fúngico, nosódio macerado de formigas, nosódio macerado do cultivo fúngico, homeopatia Belladonna, água dinamizada, isca de nim, isca de gergelim, placebo e sem intervenção, como testemunha. Para o experimento com formigas do gênero Atta os tratamentos constaram de: nosódio triturado de formiga, nosódio macerado de formiga, homeopatia Belladonna, água dinamizada, isca de nim, isca de gergelim, placebo e sem intervenção. Todos os preparados homeopáticos foram aplicados na trigésima diluição centesimal hahnemanniana (30CH), obtidos segundo a Farmacopéia Homeopática Brasileira (1997). As iscas fitoterápicas foram obtidas pela mistura de farinha de trigo, farinha de gergelim/ou óleo de nim e água, na proporção 2:2:1. Para isca placebo utilizou-se farinha de trigo e água. Foi realizada a identificação de espécies de formigas cortadeiras em 60 formigueiros para o gênero Acromyrmex e 40 formigueiros para o gênero Atta. Para o estudo de etologia foram marcados três formigueiros de ambos os gêneros, Atta e Acromyrmex. Observações foram feitas quanto ao comportamento e preferência por espécies de vegetais forrageadas ao longo do ano, por um período de 24 horas, para cada mês/época avaliada. Para o estudo etnoentomológico foi aplicado um questionário qualitativo e quantitativo referente ao envolvimento do homem com a formiga cortadeira em diferentes sistemas de produção, orgânico, de transição e convencional. As questões abordaram os tópicos: características do sistema de produção; período na atividade; identificação e conhecimento sobre métodos naturais de controle. A análise dos resultados mostrou que as iscas fitoterápicas, e os preparados homeopáticos reduziram as atividades total e forrageira para ambos os gêneros, Acromyrmex e Atta, respectivamente a partir do terceiro e sétimo dia consecutivo de aplicação para ambas atividades. O comportamento de ambos os gêneros Atta e Acromyrmex, para as atividades total e forrageira foram variáveis ao longo ano, sendo dependente das condições de temperatura e umidade relativa diária. Os estudos taxonômicos revelaram que no gênero Acromyrmex, predominaram as espécies Acromyrmex laticeps, Acromyrmex heyeri, Acromyrmex coronatus e Acromyrmex lundi, sendo as duas últimas espécies consideradas de ocorrência rara na região. O gênero Atta apresentou uma única espécie Atta sexdens piriventris. Segundo os agricultores entrevistados as formigas representam a maioria dos danos gerados nas culturas, e o seu controle, na maioria das vezes é realizado por iscas tóxicas. Os preparados homeopáticos mostraram ser uma importante ferramenta para o controle das atividades total e forrageira, para ambos os gêneros de formigas cortadeiras, com destaque para preparado homeopático nosódio de formigas. Iscas fitoterápicas de nim e gergelim afetaram o comportamento de ambos os gêneros de formigas cortadeiras.

The main aim of this thesis is to acquire basic knowledge of CAM program hyperMILL 2019 with comparison of the ball nose end mill and circle segment end mill with taper form, economical evaluation and than make force analysis of specimen from aluminium alloy by milling with spindle moulder. Another aim of this thesis is also an analysis of force effects and force directions of the milling tool, advantages by using the circle segment end mill with taper form, the most common types of aluminium alloys and their mechanical properties and next comparison of CAM program hyperMILL with other selected program in the theoretic part.

This thesis deals with the analysis of properties of hard coatings and wear resistance PVD coated technology. It focuses on the preparation, execution and evaluation of test coatings on the front ball milling cutter.

The presented diploma thesis is devided into two parts. The theoretical part deals with types of milling, the choice of the cutters, choice of material of exchangeable cutting plates and also with types of wear and their classification. The second part of the thesis deals with experiments where the power load of the tool was measured. The observed data were processed and graphs of power load were created by software. Conclusions are based on these graphs.

[pt] A indústria do petróleo realiza contínuas pesquisas para aperfeiçoar as operações de perfuração, aumentando a taxa de penetração e reduzindo o tempo não produtivo. Diversos estudos analisam o processo de corte em rocha utilizando brocas PDC (Polycrystalline Diamond Compact). Experimentos como o ensaio de cortador único simulam a interação existente entre a rocha e o cortador. Além disso, modelos numéricos têm sido criados para fazer o mesmo tipo de análise obtendo estimativas concordantes com resultados experimentais. No entanto, os ensaios experimentais geram altos custos de investimento, e por sua vez, as simulações numéricas demandam tempo muito alto para realizar análises de boa qualidade. Modelos analíticos procuram eliminar o fator custo e tempo, gerando resultados confiáveis da simulação do processo de corte, similares aos resultados das análises experimentais e numéricas. Os modelos analíticos aqui apresentados permitem estimar as forças medidas pelo cortador no processo de corte, partindo das propriedades mecânicas da rocha. Os modelos levam em conta o equilíbrio de forças no instante do corte e consideram, para o cálculo das forças, a sua geometria e as propriedades de resistência do material. A rocha utilizada no presente trabalho é um evaporito. A aplicação deste tipo de metodologia para corte em halita obriga a considerar no modelo analítico o incremento nas forças devido ao comportamento dúctil do material, à existência de deformações plásticas e à aglomeração de material na face do cortador a fim de obter uma melhor estimativa das forças de corte. Conseguem-se estimativas aceitáveis com dois dos modelos avaliados nas condições de pressões atmosféricas e altas pressões de confinamento. / [en] The oil industry carries out continuous research to improve drilling operations, to increase the penetration rate and to reduce non-productive time. Several studies analyze the rock cutting process using PDC bits (Polycrystalline Diamond Compact). Experiments with a single cutter machine measure the interaction between the rock and the cutter. Furthermore, numerical models aim to simulate the physical process and calculate results as possible consistent with experimental data. However, experimental tests are expensive and robust and numerical simulations are time consuming. Analytical models aim to reduce both cost and time factor, while providing reliable results for simulation of cutting process. The analytical models presented here allow us to estimate the forces measured on the cutter in the rock cutting process. The models take into account the balance of forces acting on the cutter face and these forces are calculated based on geometry and material properties of both cutter and rock. The rock evaluated in this work is an evaporite. The application of such type of methodology to simulate the salt rock drilling requires the analytical model to consider the increase of forces due to rock ductile behavior and the existence of plastic deformation and agglomeration of material on the cutter s face in order to obtain adequate estimation of the cutting forces. Two of the evaluated models in this work presented agreement with experimental results, both under atmospheric and high pressure conditions.

The Master Thesis work this report is based upon has been conducted in cooperation with Svea Teknik AB. Svea Teknik is a consultant firm which is developing parts of a tunnel boring machine on behalf of Atlas Copco. The machine is being developed to mechanically excavate hard rock by fixating itself in the tunnel and then press a large rotating cutter-wheel equipped with disc-cutters against the tunnel wall. The disc-cutters are the tools that are in direct contact with the hard rock and are therefore exposed to extensive wear and needs to be replaced on a regular basis.The purpose of this Master Thesis has been to develop a service equipment that will enable time effective and safe changes of disc-cutters. The disc-cutters have a diameter of 17 inches and weigh about 130 kg. The available space in the tunnel is very limited which puts strict requirements on the size of the service equipment.A specification of requirements was set up based on the background study made in the Master Thesis. Concepts to solve the problem were then generated and evaluated against each other.A concept consisting of a wagon with three slots for disc-cutter transport, a foldable crane with a hoist and a lifting tool adapted to the disc-cutters were chosen for further development. Since the concept was quite extensive the decision was made to focus the work around the lifting tool.By loading new disc-cutters onto the driven wagon together with the foldable crane and the lifting tool, the equipment can be transported past the machine in the tunnel and the crane can then be set up in front of the machine's cutter-wheel. The lifting tool is then lifted by the hoist to enable the disc-cutters in the cutter-wheel to be replaced.The lifting tool consists of two claws that close around the disc-cutter to fixate it geometrically and a counter weight to enable easy positioning of the disc-cutter by hand. The lifting tool is dimensioned according to two different load cases and was verified by FE-analysis.Recommendations for future work and more detailed design were set up. / Examensarbetet denna rapport baseras på, har utförts i samarbete med Svea Teknik AB. Svea Teknik är ett konsultföretag som på uppdrag av Atlas Copco utvecklar delar av en gruvmaskin för tunnelborrning. Maskinen konstrueras för att mekaniskt krossa berget genom att fixera sig i tunnelgången och pressa ett stort skärhjul utrustat med diskformade s.k. kuttrar mot bergväggen samtidigt som skärhjulet roterar. Då kuttrarna är de verktyg som står i direkt kontakt med berget slits de markant och måste bytas ut för service med jämna mellanrum.Detta examensarbete har syftat till att utveckla en serviceutrustning för att möjliggöra snabba och smidiga byten av dessa kuttrar som har en diameter på 17 tum och väger ca 130 kg. Då utrymmet i tunneln är väldigt begränsat finns stora krav på utrustningens storlek.En kravspecifikation, baserad på examensarbetets bakgrundsstudie, utarbetades för att ligga till grund för de genererade koncept som sedan utvärderades gentemot varandra.Efter att ett koncept bestående av en transportvagn med plats för tre kuttrar, en vikbar kran med telfer samt ett specialanpassat kloförsett lyftverktyg hade valts togs beslutet att fokusera arbetet kring lyftverktyget för att begränsa projektets omfång.Genom att lasta nyservade kuttrar på den drivna transportvagnen tillsammans med den hopvikta kranen och lyftverktyget kan den ledas fram förbi maskinen i tunneln och kranen monteras upp framför maskinens skärhjul. Lyftverktyget hängs sedan upp i kranen för att möjliggöra att kuttrar lossas respektive monteras.Lyftverktyget består av två klor som sluts runt kuttern för att fixera den formbetingat samt en motvikt för att för hand kunna ändra rotationen av verktyget kring infästningspunkten. Lyftverktyget dimensionerades utifrån två uppsatta lastfall och verifierades sedan med FEM-analyser