This thesis solves actual engineering tasks from the field of motorcycle industry. The first part describes the design of several plastic parts for Czech motorcycle Blata125. The design of injection moulds for selected parts is described in second part of the thesis.

By combining laboratory experiments with field work, I have looked at the following aspects of cellular slime mould (CSM) biology: (a) the genetic structure of social groups (fruiting bodies) in the wild and its relation to the role of large mammals as dispersal agents; (b) social behaviour in clonal, intra-species polyclonal and interspecies social groups and (c) fitness-related trade-offs with respect to life history traits as a possible mechanism for coexistence and cooperative behaviour in CSMs. The major findings of this study are as follows: (a) individuals belonging to different strains of a species, different species and genera occur in close proximity, even on a speck of soil (250µm–1mm) or the same dung pat; (b) social groups formed in the wild by Dictyostelium giganteum and D. purpureum are generally multiclonal; (c) genetically diverse strains can co-aggregate and form chimaeric social groups; (d) in chimaeric social groups, strains differ in their relative sporulation efficiencies; (e) the fact that strains co-exist in spite of this may be attributable in part to trade-offs between various fitness-related traits as can be demonstrated in the case of wild isolates of D. giganteum in pair wise mixes. The Dictyostelids or CSMs are haploid, eukaryotic, soil dwelling social amoebae with an unusual life cycle (Bonner, 1967; Raper, 1984). They exist as single cells in the presence of food (bacteria, yeast, fungal spores). Once the food is exhausted, they enter the social phase of their life cycle. Approximately 102 to 106 amoebae aggregate at a common collection point and form a starvation resistant structure called the fruiting body. In many species a fruiting body is made up of an aerial stalk of dead cells and a ball of viable spores on top. In other CSM species (not part of this study), all amoebae in a fruiting body differentiate into spores and the stalk is an extracellular secretion. The CSM life cycle raises fundamental questions related to the evolution of an extreme form of ‘altruism’ in the form of reproductive division of labour in social groups. The spore–stalk distinction in the CSMs is analogous to the germ–soma distinction in metazoans, although, the CSMs achieve multicellularity not by repeated divisions of a zygote but via the aggregation of many cells which may or may not be clonally related (Bonner, 1982; Kaushik and Nanjundiah, 2003). Social behaviour in the CSMs offers interesting parallels to what is seen in the social insects (Gadagkar and Bonner, 1994). The origin and maintenance of ‘altruism’ has been a long-standing issue in sociobiology. Because of their simple life cycle and experimental tractability, the CSMs are ideal for studying the evolutionary origin and maintenance of social behaviour, in particular of ‘altruistic’ behaviour. By elevating spores above soil level, stalk cells, protect them from noxious compounds and predators present in soil and also facilitate their passive dispersal. In the course of doing so they die. The death of stalk cells appears to be an extreme form of altruism. Knowledge of the genetic structure of social groups and populations including patterns of kinship is essential for modelling the evolution of ‘altruism’. Thus, it is important to understand the genetic structure of CSM social groups in the wild. For this, social groups (fruiting bodies) of CSMs were isolated from undisturbed forest soil of the Mudumalai forest reserve in South India. Soil and animal dung samples were brought to the laboratory and quasi-natural social groups were generated by inoculating the samples on non-nutrient agar. The fruiting bodies from various CSM species were formed by these isolates. Since soil and dung samples were not perturbed in any way, the fruiting bodies were formed as they would have in nature. When compared to soil, dung samples contained a higher CSM diversity and more CSM propagules. The presence of CSMs in fresh animal dung makes it likely that they were transported and dispersed over long distances through the gut of these animals. Such dispersal is likely to be preceded by a thorough mixing of spores in the gut. That increases the probability of co-occurrence of different genotypes in a social group. This possibility was confirmed by genetically characterizing spores in social groups of Dictyostelium giganteum and D. purpureum collected from the wild. Random amplification of polymorphic DNA (RAPD), a simple and reliable molecular technique, was used for genotyping spores within a fruiting body. 17 fruiting bodies (8 from animal dung and 9 from soil) were studied. 15 out of 17 (9 out of 11 of D. giganteum and 6 out of 6 D. purpureum) were polyclonal; the minimum number of distinct clones in a single fruiting body was 3 to 7 (animal dung) and 1 to 9 (soil). Therefore in D.giganteum and D. purpureum, chimaeric social groups seem to be the norm. This suggests that other species of CSMs form intra-species chimaeric social groups in wild, though clonal fruiting bodies occur too. The next objective of this thesis was to test whether genetic heterogeneity had functional consequences. That is, when different strains come together in an aggregate, do they contribute equally to the reproductive (spore) and non-reproductive (stalk) pathways? Amoebae of different clones (strains) of D. giganteum or D. purpureum were mixed and developed together and the number of spores formed by each strain was counted. These experiments confirmed that strains of D. giganteum or D. purpureum can aggregate together and form chimaeric fruiting bodies. The ability to mix (measured as the frequency of chimaerism) depended on the strains used and varied from one mix to another. One strain was often found to ‘exploit’ the other during sporulation, that is, it formed more spores than its expected share. Despite this, strains are found in very close proximity in the soil, which raises an important question: when one strain is more efficient at sporulating than other, how can the two co-exist stably? To investigate what might lie behind the stable co-existence of strains, I studied various fitness-related traits in the life cycle of D. giganteum. They included the rate of cell division, the time taken to go through multicellular development, the efficiency of slug migration through various depths of soil and the probability of differentiation into a spore. Measurements were carried out on strains taken separately and on their pair wise mixes. Five different D. giganteum wild strains (46a3, 46d2, 48.1a1, F5 and F16) were used. All were isolated from the Mudumalai forest (India). 46a3 and 46d2 came from soil within 10 cm of each other, 48.1a1 from soil about 200m away from 46a3; and F5 and F16 from the same fruiting body (Kaushik et al., 2006; Sathe et al., 2010). Members of a pair differed significantly in the measured fitness-related traits. For example, in the case of 48.1a1 and 46d2, 48.a1 grew faster than 46d2 both individually and in a mix. After starvation, 48.1a1 formed fruiting bodies faster than 46d2; a mix of the two developed at the rate of the faster member, implying that the slower one (46d2) gained from the association with 48.1a1. During slug migration, slugs formed by 48.1a1 came up through a higher depth of soil than 46d2 slugs and did so earlier. Chimaeric slugs were like the more efficient member, 48.1a1, in terms of the maximum depth of soil that was covered, but like the less efficient member, 46d2, in terms of the time taken for slugs to be seen on the soil surface. 48.1a1 seems to have an advantage over 46d2 in all these respects. However, during sporulation in chimaeras, 48.1a1 formed relatively fewer spores than 46d2. Similar trade-offs were seen in all mixes. F5 and F16 displayed an unexpected feature during sporulation; the spore-forming efficiency of either strain depended on its proportion in the initial mix in a frequency-dependent manner that was consistent with a stable equilibrium. Thus, trade-offs between different fitness-related traits contribute to the co-existence of strains. Next, I studied interactions between members of different CSM species. Several species of CSMs were isolated from the same environment (Sathe et al., 2010); a question of interest was to see if amoebae of different species came together to form a chimaeric multicellular body. Five strains (two D. purpureum and three D. giganteum) were used in this study. Amoebae of D. giganteum and D. purpureum co-aggregated. However, there were factors that caused amoebae of the two species to sort out thereafter. The extent of segregation differed between strains, a characteristic that inter-species mixes share with intra-species mixes. In conclusion, the ability of cellular slime moulds to form multiclonal social groups in the wild suggests that one should look to factors in addition to close relatedness to understand the evolution of CSM social behaviour. The existence of fitness-related trade-offs between different traits indicates that individual-level selection can also contribute to the maintenance of chimaeric social groups.

Aproveito este espaço para contar um pouco da minha trajetória com as abelhas, mas também para falar sobre as atividades desenvolvidas e possibilidades surgidas no decorrer do curso de Doutorado, informações estas que normalmente passam despercebidas. Nascido em Salvador, tive meu primeiro contato com as abelhas com pouco mais de 12 anos por iniciativa de meu pai, que nesta época já era um entusiasta pela atividade e possuía conhecimentos práticos. Alguns anos após, fizemos nosso primeiro curso de iniciação em apicultura para consolidar as nossas experiências práticas e as informações obtidas em literatura. Terminei por cursar a graduação em Engenharia Agronômica na Escola de Agronomia da UFBA, atualmente Centro de Ciências Agrárias, Ambientais e Biológicas da Universidade Federal do Recôncavo da Bahia. Foi um período de crescimento em que me envolvi com atividades de iniciação científica, em outras áreas que não apicultura. Já no mestrado, me foi dada a oportunidade de trabalhar com um grupo de abelhas até então novo para mim, os meliponíneos, e de ter como orientador o Prof. Dr. Carlos Alfredo Carvalho, pessoa que me direcionou para o futuro curso de doutorado na USP, dando continuidade à linha de pesquisa iniciada no mestrado. Em 2004 iniciei o meu doutoramento na ESALQ/USP sob orientação do Prof. Dr. Luis Carlos Marchini. Fazendo um balanço desta última etapa, além do desenvolvimento das atividades regulares do programa tive a oportunidade de me envolver com a formulação de projetos de pesquisa para agências de fomento, de participar de eventos nacionais e internacionais, de publicar artigos científicos e de consolidar parcerias de trabalho no Brasil e no exterior. Em síntese, este período de doutorado que se encerra (2004 - 2008) pode ser representado em números por: quatro cursos realizados como formação complementar, quatro premiações em eventos científicos, nove trabalhos publicados em periódicos (alguns submetidos antes de ingressar no doutorado), quatro livros, três capítulos de livros, três cartilhas, dois textos em revista de divulgação, quatro trabalhos completos publicados em anais de congressos, 40 resumos, 17 trabalhos apresentados e participação em 12 eventos técnico-científicos; além do envolvimento em atividades de monitoria junto a disciplinas de graduação, treinamento este fundamental para uma futura atividade de docência. Acredito que todas estas amizades feitas, parcerias consolidadas, atividades desenvolvidas e produções decorrentes do doutorado contribuirão de forma substancial e decisiva para esta nova etapa que se inicia em minha vida. / The stingless bees honey is a product presenting a growing market demand but, in spite of its consumption as food and even medicinal use, there are few studies to define quality standards for its commercialization. This work was carried out to determine the physico-chemical characteristics and microbiological quality of honey samples produced by meliponid species from Bahia State, Brazil, contributing to the establishment of quality control standards of this product. Forty-seven samples collected from December 2004 to May 2006 were analyzed, being determined their physico-chemical characteristics and microbiological quality, regarding to the standard counting of moulds and yeasts, and presence of microorganisms of the coliform group. Concerning the physico-chemical characteristics, the obtained medium values, excepting moisture content, fulfill the quality criteria established by the current Brazilian Legislation. Considering the number of samples individually disqualified, adjustments in reducing sugars limits should be made for best attend to the requirements of meliponid honey, as well as the use of the diastasic activity in the Melipona honeys as quality criterion. In the microbiologic analyses, 53.2% of the honey samples presented standard counting for moulds and yeasts above the maximum value allowed by the Brazilian Legislation. For microorganisms of the coliform group only one sample was positive for coliform at 35ºC. The presence of these microorganisms, mainly moulds and yeasts, even in samples aseptically harvested indicates the need of identification of this microbiota and its possible natural occurrence in the honey produced by this group of bees.

Das Ziel der Untersuchungen war die Ermittlung der Grenzbedingungen von Lagerungsdichte und äußerer Luftabschlußgüte (Gasdurchlässigkeit des Zudeckmaterials), unter denen Schimmelpilzwachstum während der Silagelagerung eingeschränkt wird. Den Schwerpunkt bildeten 10 Praxis- und Laborsilierversuche mit extensiv erzeugtem Grünfutter, das aufgrund relativ hoher Rohfasergehalte allgemein schwer verdichtbar ist. In den Silagen wurde die Pilzkeimzahl sowie der Gehalt an Ergosterin und Roquefortin C bestimmt. Für die Analyse des Ergosteringehaltes wurde eine neue Methode entwickelt. Die Gasdurchlässigkeit von 1 - 8 Folienlagen der verwendeten Silierstretchfolie wurde radiometrisch gemessen. Im Versuchszeitraum (1995 - 1997) wurde Grünfutter von jahreszeitlich verschiedenen Aufwüchsen unter landwirtschaftlichen Praxisbedingungen einsiliert. Mit Hilfe drei verschiedener Ballenpressen wurden insgesamt 165 Silageballen mit unterschiedlichen Lagerungsdichten erzeugt. Die Folienlagenzahl und die Lagerdauer bei den Silageballen wurde gestaffelt. Hierdurch sollte der Einfluß des Luftabschlusses auf Gärqualität, Pilzbefall und Mykotoxingehalt in den Silagen untersucht werden. Im Labor wurden Einflußfaktoren wie der Trockenmassegehalt (T-Gehalt) des Siliergutes geprüft. In den Praxisversuchen trat bei einem T-Gehalt < 400 g/kg unabhängig von Lagerungsdichte und äußerem Luftabschluß eine relativ starke Buttersäurebildung in den Silagen auf. Dagegen wurden bei einem T-Gehalt > 450 g/kg bei ausreichendem Luftabschluß buttersäurefreie (£ 0,3 % T) Silagen erzielt. Hier lag offenbar ein ausreichender T-Gehalt zur Sicherung einer guten Gärqualität vor. In allen Versuchen stellte die Erhöhung der Lagerungsdichte die primäre Grundlage zur Erzeugung eines ausreichenden Luftabschlusses in den Silagen dar. Die äußere Luftabschlußgüte besaß im Vergleich dazu sekundären Charakter. Als notwendige Grenzbedingungen des Luftabschlusses zur Erzeugung einer guten Gärqualität sowie zur Einschränkung von Pilzbefall in den Silagen erwiesen sich: (1) eine Lagerungsdichte von mindestens 200-210 kg T/m³ und (2) eine maximale Gasdurchlässigkeit des Zudeckmaterials von 1,7 l/m² in 24 Stunden (6 Folienlagen der verwendeten Silierstretchfolie). Ein ausreichender Luftabschluß war die Voraussetzung für die Wirksamkeit von Silierzusätzen hinsichtlich der Einschränkung von Pilzbefall und der Verbesserung der Gärqualität in den Silagen. Die Mykotoxinbildung in den Silagen, die am Beispiel des Vorkommens von Roquefortin C (ROF) untersucht worden ist, wurde ungeachtet von Lagerungsdichte und äußerem Luftabschluß vor allem durch den T-Gehalt des Siliergutes beeinflußt. Bei einem T-Gehalt < 450 g/kg enthielten etwa 88 % der in diesem T-Bereich vorliegenden Silagen Roquefortin C. Bei einem T-Gehalt zwischen 450 und 550 g/kg enthielten noch etwa 10 % der hier vorliegenden Silagen Roquefortin C, überwiegend aber im Bereich der Nachweisgrenze von ³ 0,05 mg ROF/kg T. Bei einem T-Gehalt > 550 g/kg wurde in den Silagen Roquefortin C nicht nachgewiesen. Die insgesamt in den Silagen gemessenen Gehalte an Roquefortin C waren mit < 1,0 mg ROF/kg T relativ niedrig. Sie sind bei Verfütterung der Silagen an Wiederkäuer nach dem gegenwärtigen Erkenntnisstand toxikologisch als nicht kritisch einschätzbar. / The goal of the investigation was to determine the boundary conditions of compactness and hermetic level of covering material (permeability of the covering material) to inhibit mould growth during silage storage. The emphasis was based on 10 practical and lab ensiling experiments with green forage having a relatively high content of raw fiber, which in general is difficult to compress. The silages were investigated for their mould count, as well as for their content of ergosterol and roquefortine C. A new method was developed to analyse the ergosterol content. The permeability of 1 - 8 numbers of wraps of the used ensiling stretch film was measured by radiometric methods. During the experimental time (1995 - 1997), green forage from seasonally different bites were ensiled under practical agricultural conditions. Using three different balers, a total of 165 bales were wrapped at various compactness levels. The numbers of wraps and the storage period of the bales were staggered. Hereby the influence of air exclusion on fermentation quality, mould growth and mycotoxin content in the silage should be tested. In the lab, factors such as the dry matter content (d-content) of the green forage were tested. In the practical experiments, the results showed that at a d-content of < 400 g/kg, a relatively high amount of butyric acid formed in the silages, independent of the compactness and hermetic level of the covering material. Whereas, at a d-content of > 450 g/kg, no butyric acid (£ 0,3 % dry matter) was found in the silages with sufficient air exclusion. Here, the d-content to ensure a good fermentation quality was sufficient. In all experiments, the primary way to generate sufficient air exclusion in the silages was to increase the compactness. Compared with this, the hermetic level of covering material had secondary character. To get a sufficient fermentation quality, as well as an inhibition of mould growth in the silages, necessary boundary conditions of air exclusion were: (1) a compactness of at least 200-210 kg T/m³ and (2) a maximum permeability of the covering material of 1,7 l /m² in 24 hours (6 numbers of wraps of the used ensiling stretch film). Sufficient air exclusion was necessary for the effectiveness of the silage additives in inhibiting mould growth and improving the fermentation quality in the silages. The mycotoxin formation in the silages, investigated by measuring the occurrence of roquefortine C (ROF), was influenced mainly by the dry matter content of the ensiled material, regardless of the compactness and hermetic level of covering material. At a dry matter content of < 450 g/kg, about 88 % of the silages contained roquefortine C. Between 450 to 550 g/kg dry matter about 10 % of the silages containing roquefortine C, however, at low levels in the range of the detectable content of ³ 0,05 mg ROF/kg dry matter. At a dry matter content of > 550 g/kg, no roquefortine C was found in the silages. Summarised, the measured amounts of < 1,0 mg ROF/kg roquefortine C in the silages is considered to be relatively low. Within the actual state of knowledge of toxicology, it is not considered dangerous to feed ruminant animals with silages containing these low amounts of roquefortine C.

Outgrowth of spoilage yeasts and moulds and post-processing acidification can limit the shelf-life of some fermented dairy products including fresh lactic curd cheeses. The possibility of using high pressure processing (HPP) for controlling these problems was investigated in a commercially manufactured fresh lactic curd cheese (pH 4.3-4.4) and fermented milk models (pH 4.3-6.5). The effects of HPP at 300 and 600 MPa on inactivation of glycolytic enzymes of lactic acid bacteria were also evaluated. Fresh cheeses made from pasteurised bovine milk using a commercial Lactococcus starter preparation were treated with high pressures ranging from 200 to 600 MPa (less than or equal to 22°C, 5 min) under vacuum packaging conditions and subsequently stored at 4°C for 8 weeks. Treatment at greater than or equal to 300 MPa substantially reduced the viable count of Lactococcus and effectively prevented the outgrowth of yeasts and moulds for 6 to 8 weeks without adversely affecting the sensory and textural attributes of the product. However, it had no significant effects (p less than 0.01) on variation of titratable acidity during storage. Fermented milk models were prepared by individually growing Lactococcus lactis subsp. lactis C10, Lactococcus lactis subsp. cremoris BK5, Streptococcus thermophilus TS1, Lactobacillus acidophilus 2400 and Lactobacillus delbrueckii subsp. bulgaricus 2517 in UHT skim milk and diluting the resulting fermented milk with UHT skim milk up to pH 6.5. Pressure treatment of the milk models at pH 5.2 resulted in substantial inhibition of post-processing acidification during storage and markedly reduced the viable count of Lactococcus at both 300 and 600 MPa and other bacteria only at 600 MPa. Treatment of the milk model at 600 MPa decreased the viable counts of Candida zeylanoides and Candida lipolytica (wildtype spoilage yeasts of lactic curd cheese, added as challenge cultures) from 105 CFU mL-1 to below the detection limit (log 0 CFU mL-1) at all pH levels tested (pH 4.3-6.5) and effectively controlled their outgrowth for 8 weeks. Treatment of milk model at 300 MPa had a similar effect only on C. zeylanoides. The viable count of C. lipolytica was reduced by 2.6, 2.4 and 2.3 logs by treatment at 300 MPa at pH levels of 4.3, 5.2 and 6.5, respectively, which subsequently recovered by 2.9, 2.8 and 3.2 logs within 3 weeks. Glycolytic enzymes of various starter bacteria showed different responses to pressure treatment. The lactate dehydrogenase in L. lactis subsp. lactis and Lb. acidophilus was quite resistant to pressures up to 600 MPa, but it was almost completely inactivated in S. thermophilus at pressure levels as low as 300 MPa. The â-galactosidase in Lb. acidophilus was more pressure stable than â-galactosidase in S. thermophilus and Phospho-â-galactosidase in L. lactis subsp. lactis. The findings of this study suggests HPP at 300-600 MPa as an effective method for controlling the outgrowth of some spoilage yeasts and moulds in fresh lactic curd cheeses. The results obtained with selected lactic acid bacteria in fermented milk models can be used to assist in establishing HPP operating parameters for development of new generation cultured dairy products, of reduced acidity and extended shelf-life.

Monolitinė statyba yra viena iš sparčiausiai besivystančių ir labiausiai perspektyvių statinių statybos technologijų. Naujausios technologijos ir medžiagos leidžia taupyti darbo sąnaudas, tuo pa��iu mažindamos projektų išlaidas. Visame pasaulyje plačiai taikomos įvairiausios monolitinės statybos technologijos, surenkamosios monolitinės konstrukcijos ir liktiniai klojiniai. Naujausios technologijos yra techniškai racionalios, universalios ir ekonomiškos. Lietuvoje šios technologijos ir konstrukcijos dar mažai žinomos ir taikomos tik individualios statybos sektoriuje. Sprendžiant šią problemą numatomas darbo tikslas yra parinkti sienų ir perdang����� įrengimo racionalų variantą pagal sukurtą modelį. Darbe analizuojamos sienų ir perdangų įrengimo technologijų rūšys, įvertinant kiekvienos rūšies privalumus ir trūkumus. Atliekama įvairių klojinių sistemų analizė. Suformuojami rodikliai (kriterijai) racionaliam sienų ir perdangų įrengimo sprendimui parinkti. Visi klojinių sistemos variantai analizuojami naudojant ekspertų metodą. Apibendrinus gautų skaičiavimų rezultatus, pateikiami racionalūs sienų ir perdangų įrengimo variantai. / Monolithic building - one of the most promising and swiftly developing construction technologies. The newest technologies and materials make it possible substantially to economize working resources, thus decreasing the expenditures. In the entire world are used the most varied technologies of monolithic building, composite constructions and nondetachable planking. The newest technologies are technically rational, universal and it is economically advantageous. In Lithuania these technologies and constructions are thus far little familiar and are used only in the sector of individual building. Solving this problem, the purpose of the work - to select the rational version of the construction of walls and slabs on the created model. In the work the analysis of the forms of technologies on the construction of walls and slabs is conducted, taking into account and deficiencies in each of the forms. Analysis of different systems of formwork is produced. Are formed criteria, for the selection of the rational solution. All versions of formwork systems are analyzed with the aid of the expert method. After generalizing the obtained results, the rational solutions by the construction of walls and slabs are proposed.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 5 uppsatser.

Este trabalho abrange o estudo do processo convencional de fabricação de moldes e matrizes, ou seja, passando por processos de fresamento, eletroerosão e lixamento. Estes três processos foram aplicados ao material AISI H13, usualmente empregado na fabricação de moldes e matrizes. Além disso, foram variadas condições de usinagem, como o uso de fluído de corte. No material, a integridade da superfície foi avaliada através: da rugosidade; da dureza; da existência de deformações plásticas, trincas, tensões residuais; entre outros. No processo de fresamento foram encontradas deformações plásticas que variam de 5 μm a 8 μm. Já para o processo de EDM, foi encontrada uma camada branca de aproximadamente 20 μm. Para o lixamento constataram-se marcas de riscos e micro-rupturas. O perfil de dureza encontrado para as condições empregadas mostram um valor médio menor próximo a borda do que para a base do material. Os resultados de ruído magnético de Barkhausen mostraram que os processos de usinagem empregados modificaram a estrutura da sub-superfície dos corpos-de-prova usinados, o que pode ser percebido também para os valores medidos de tensão residual pela técnica de difração de raio X. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-05-14T18:16:32Z No. of bitstreams: 1 Dissertacao Juliano M Oliveira.pdf: 16772078 bytes, checksum: 2563eb47fc3f04e372ff4f36edadc956 (MD5) / Made available in DSpace on 2014-05-14T18:16:32Z (GMT). No. of bitstreams: 1 Dissertacao Juliano M Oliveira.pdf: 16772078 bytes, checksum: 2563eb47fc3f04e372ff4f36edadc956 (MD5) / This work includes the conventional way of die and mold production. Process such as milling, EDM and sanding are discussed. These three processes of die and mold making were applied to the AISI H13 material, that is wide used by die and mold makers to produce the mold s parts. Besides that, some conditions were modified such as the cutting fluids applications. The surface integrity was observed in the machined material by the follow itens: the roughness, the hardness, the plastic deformations existence, chippings, residual tensile, among others features were observed. In the milling process the plastic deformations varied from 5 μm to 8 μm and a white layer with about 20 μm were found to the EDM process. In the sanding process were found risks mark s and micro-breaches. The average value measured for the hardness profile shows that in the boundary there is a low value than in the material base. The Barkhausen noise results show that the machining process employed had changed the sub-surface of the blank material. This changed can be seen analyzing the stress results measured by X ray diffraction.

Aproveito este espaço para contar um pouco da minha trajetória com as abelhas, mas também para falar sobre as atividades desenvolvidas e possibilidades surgidas no decorrer do curso de Doutorado, informações estas que normalmente passam despercebidas. Nascido em Salvador, tive meu primeiro contato com as abelhas com pouco mais de 12 anos por iniciativa de meu pai, que nesta época já era um entusiasta pela atividade e possuía conhecimentos práticos. Alguns anos após, fizemos nosso primeiro curso de iniciação em apicultura para consolidar as nossas experiências práticas e as informações obtidas em literatura. Terminei por cursar a graduação em Engenharia Agronômica na Escola de Agronomia da UFBA, atualmente Centro de Ciências Agrárias, Ambientais e Biológicas da Universidade Federal do Recôncavo da Bahia. Foi um período de crescimento em que me envolvi com atividades de iniciação científica, em outras áreas que não apicultura. Já no mestrado, me foi dada a oportunidade de trabalhar com um grupo de abelhas até então novo para mim, os meliponíneos, e de ter como orientador o Prof. Dr. Carlos Alfredo Carvalho, pessoa que me direcionou para o futuro curso de doutorado na USP, dando continuidade à linha de pesquisa iniciada no mestrado. Em 2004 iniciei o meu doutoramento na ESALQ/USP sob orientação do Prof. Dr. Luis Carlos Marchini. Fazendo um balanço desta última etapa, além do desenvolvimento das atividades regulares do programa tive a oportunidade de me envolver com a formulação de projetos de pesquisa para agências de fomento, de participar de eventos nacionais e internacionais, de publicar artigos científicos e de consolidar parcerias de trabalho no Brasil e no exterior. Em síntese, este período de doutorado que se encerra (2004 - 2008) pode ser representado em números por: quatro cursos realizados como formação complementar, quatro premiações em eventos científicos, nove trabalhos publicados em periódicos (alguns submetidos antes de ingressar no doutorado), quatro livros, três capítulos de livros, três cartilhas, dois textos em revista de divulgação, quatro trabalhos completos publicados em anais de congressos, 40 resumos, 17 trabalhos apresentados e participação em 12 eventos técnico-científicos; além do envolvimento em atividades de monitoria junto a disciplinas de graduação, treinamento este fundamental para uma futura atividade de docência. Acredito que todas estas amizades feitas, parcerias consolidadas, atividades desenvolvidas e produções decorrentes do doutorado contribuirão de forma substancial e decisiva para esta nova etapa que se inicia em minha vida. / The stingless bees honey is a product presenting a growing market demand but, in spite of its consumption as food and even medicinal use, there are few studies to define quality standards for its commercialization. This work was carried out to determine the physico-chemical characteristics and microbiological quality of honey samples produced by meliponid species from Bahia State, Brazil, contributing to the establishment of quality control standards of this product. Forty-seven samples collected from December 2004 to May 2006 were analyzed, being determined their physico-chemical characteristics and microbiological quality, regarding to the standard counting of moulds and yeasts, and presence of microorganisms of the coliform group. Concerning the physico-chemical characteristics, the obtained medium values, excepting moisture content, fulfill the quality criteria established by the current Brazilian Legislation. Considering the number of samples individually disqualified, adjustments in reducing sugars limits should be made for best attend to the requirements of meliponid honey, as well as the use of the diastasic activity in the Melipona honeys as quality criterion. In the microbiologic analyses, 53.2% of the honey samples presented standard counting for moulds and yeasts above the maximum value allowed by the Brazilian Legislation. For microorganisms of the coliform group only one sample was positive for coliform at 35ºC. The presence of these microorganisms, mainly moulds and yeasts, even in samples aseptically harvested indicates the need of identification of this microbiota and its possible natural occurrence in the honey produced by this group of bees.

Este trabalho abrange o estudo do processo convencional de fabricação de moldes e matrizes, ou seja, passando por processos de fresamento, eletroerosão e lixamento. Estes três processos foram aplicados ao material AISI H13, usualmente empregado na fabricação de moldes e matrizes. Além disso, foram variadas condições de usinagem, como o uso de fluído de corte. No material, a integridade da superfície foi avaliada através: da rugosidade; da dureza; da existência de deformações plásticas, trincas, tensões residuais; entre outros. No processo de fresamento foram encontradas deformações plásticas que variam de 5 μm a 8 μm. Já para o processo de EDM, foi encontrada uma camada branca de aproximadamente 20 μm. Para o lixamento constataram-se marcas de riscos e micro-rupturas. O perfil de dureza encontrado para as condições empregadas mostram um valor médio menor próximo a borda do que para a base do material. Os resultados de ruído magnético de Barkhausen mostraram que os processos de usinagem empregados modificaram a estrutura da sub-superfície dos corpos-de-prova usinados, o que pode ser percebido também para os valores medidos de tensão residual pela técnica de difração de raio X. / This work includes the conventional way of die and mold production. Process such as milling, EDM and sanding are discussed. These three processes of die and mold making were applied to the AISI H13 material, that is wide used by die and mold makers to produce the mold s parts. Besides that, some conditions were modified such as the cutting fluids applications. The surface integrity was observed in the machined material by the follow itens: the roughness, the hardness, the plastic deformations existence, chippings, residual tensile, among others features were observed. In the milling process the plastic deformations varied from 5 μm to 8 μm and a white layer with about 20 μm were found to the EDM process. In the sanding process were found risks mark s and micro-breaches. The average value measured for the hardness profile shows that in the boundary there is a low value than in the material base. The Barkhausen noise results show that the machining process employed had changed the sub-surface of the blank material. This changed can be seen analyzing the stress results measured by X ray diffraction.