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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Desenvolvimento de um novo aço para moldes de plástico

Ribeiro, Paulo Sérgio 26 January 2010 (has links)
Made available in DSpace on 2016-04-18T21:36:01Z (GMT). No. of bitstreams: 3 Paulo Sergio Ribeiro1.pdf: 2109374 bytes, checksum: 1ff4b8a7334397d794c09c418079e776 (MD5) Paulo Sergio Ribeiro2.pdf: 3132872 bytes, checksum: 48f547e687886b7890e80ec7a490f153 (MD5) Paulo Sergio Ribeiro3.pdf: 2689619 bytes, checksum: 98d138df083b0e4eea2c480703b1c714 (MD5) Previous issue date: 2010-01-26 / Uma nova liga a base de ferro (aço) para moldes plásticos foi obtida com características melhoradas quando comparada aos materiais usualmente utilizados no mercado. Os materiais, existentes no mercado, usados como referência neste trabalho, também não são indicados para utilização que necessitem acabamentos especiais. Para aplicações de uso restrito ou que requeiram acabamentos especiais, como texturização, por exemplo, outros testes, teriam que ser realizados. Com estas características atingiu-se melhor produtividade do molde, opções de menor custo, dependendo da variação de custo de liga, no mercado internacional, bem como uma redução no consumo de energia na produção das peças, por conta da melhoria da condutividade térmica. Como resultado deste trabalho atingiu-se a manutenção das características mecânicas quando comparado aos aços equivalentes comerciais em uso, obtendo ganho expressivo em condutividade térmica. Também foi obtida a possibilidade de obter-se um aço com estrutura compatível com a aplicações do aço DIN 1.2738 até 600 mm de espessura, com menor adição de elementos de liga.
212

Sclerotinia sclerotiorum: características morfológicas, agressividade, sensibilidade \"in vitro\" a fungicidas e resistência de isolados a tiofanato metílico / Sclerotinia sclerotiorum: morphological characteristics, aggressiveness, \"in vitro\" fungicides sensitivity and isolated resistance to thiophanate-methyl

Patricia Fabretti Kreyci 04 October 2016 (has links)
O mofo-branco causado pelo fungo Sclerotinia sclerotiorum se encontra amplamente disperso pelas áreas de produção em todo pais e afeta mais de 400 espécies de planta, causando perdas na produção e redução na qualidade. O controle da doença é considerado difícil, pois o patógeno forma escleródios (estruturas de sobrevivência), que podem permanecer viáveis por vários anos. Normalmente exige-se um manejo integrado, que envolve o controle químico, biológico e diversas práticas culturais, uma vez que cultivares resistentes não estão disponíveis. As adoções de estratégias sustentáveis de manejo do mofo branco dependem da compreensão do patógeno, sua etiologia, morfologia, agressividade e dinâmica populacional. Foram avaliados 150 isolados, coletados em cultivos de cenoura, couve, girassol, nabo, soja e feijão. O índice de velocidade de crescimento micelial (IVCM), a coloração da colônia e densidade do micélio, o tempo necessário para a formação do primeiro escleródio, o número de escleródios por placa, o peso em mg e a forma dos escleródios foram utilizados na caracterização dos isolados. O critério adotado nas avaliações da agressividade dos isolados foi o diâmetro das lesões após diversos intervalos de tempo, usando o método da folha destacada, em feijão e soja. Os valores foram usados para calcular a área abaixo da curva de progresso de doença. A população avaliada mostrou ampla variabilidade para as características morfológicas, fisiológicas e na agressividade. O controle químico é a estratégia mais utilizada no controle do mofo branco. No Brasil, onze ingredientes ativos estão registrados, no entanto, três são mais utilizados: fluazinam, procimidona e tiofanato metílico. O uso intensivo de fungicidas, especialmente os que agem em um unico sitio de ação, podem selecionar isolados resistentes e, consequentemente, levar a falhas de controle. A avaliação da sensibilidade de S. sclerotiorum para os fungicidas mais utilizados é fundamental para monitorar o comportamento da população. Foram avaliadas a sensibilidade de isolados brasileiros de Sclerotinia sclerotiorum a fluazinam, procimidona e tiofanato metílico, atraves de concentrações discriminatórias e valores de CI50 (concentração do fungicida que inibe em 50% o crescimento micelial). Um total de 150 isolados foi testado e nenhum se mostrou resistente a fluazinam ou procimidona. O valor da CI50 para fluazinam variou de 0,00173 ppm a 0,01284 ppm, com média de 0,007 ppm. Para procimidona, a CI50 desses isolados variou de 0,12223 ppm a 0,35916 ppm, com média de 0,21834 ppm. Foram encontrados sete isolados resistentes ao tiofanato metílico, com CI50 variando de 990-2667 ppm. Na população sensível o valor variou de 0,49 - 3,73 ppm. Foi verificada a adaptabilidade dos isolados resistentes, e esta se mostrou comparável a dos isolados sensíveis, sugerindo que os isolados possuem aptidão parasitária suficiente para competir com os isolados sensíveis em condições de campo. / The white mold caused by the fungus Sclerotinia sclerotiorum is widely dispersed in production areas in the whole country and affects more than 400 species, causing production losses and reduced quality. Disease control is considered difficult because the pathogen form sclerotia (survival structure) which can remain viable for several years. Typically this requires a integrated pest management, which involves chemical, biological control and various cultural practices, since resistant cultivars are not available. The adoption of sustainable management strategies for white mold depends on understanding the pathogen, its etiology, morphology, aggressiveness and population dynamics. We evaluated 150 isolates collected from carrots, cabbage, sunflower, turnip, soybeans and beans. Mycelial growth rate index (MIG), colony color and mycelium density, time required to form the first sclerotia, the number of sclerotia per plate, the weight in mg and sclerotia shape were used for the isolates characterization. The criteria used in the isolates aggressiveness evaluations were lesions diameter after various time intervals, using the detached leaf method in bean and soybean. The values were used to calculate the area under the disease progress curve (AUDPC). The population evaluates showed wide variability for morphological, physiological and aggressive characteristics. Chemical control is the most commonly strategy used in the control of white mold. In Brazil, eleven ingredients active are registered, however, three are most commonly used, and they are: fluazinam, procymidone and thiophanate-methyl. The intensive use of fungicides, especially those which act on at a single site of action, can select resistant isolates, and consequently lead to failure control. The evaluation of the sensitivity of S. sclerotiorum to the most commonly used fungicides is critical to monitor the behavior of the population. We assessed the sensitivity of Brazilian Sclerotinia sclerotiorum isolated to fluazinam, procymidone and thiophanate-methyl, through discriminatory concentrations and IC50 values (the fungicide concentration which inhibits 50% of the mycelial growth). A total of 150 strains have been tested, and none were resistant to fluazinam or procymidone. The IC50 value for fluazinam ranged from 0.00173 to 0.01284 ppm ppm, with an average of 0.007 ppm. For procymidone, the IC50 of these isolates ranged from 0.12223 to 0.35916 ppm ppm, averaging 0.21834 ppm. Seven isolates were found resistant to thiophanate-methyl with IC50 ranging from 990-2667 ppm. In sensitive people the value ranged from 0.49 to 3.73 ppm. Adaptability of resistant isolates was observed, and this proved to be comparable to the susceptible isolates, suggesting that the isolates have parasitic fitness enough to compete with susceptible isolates in field conditions.
213

3D printed food and customized siliconemolds : Investigating aesthetic appearance and food preparingmethods for a dysphagia diet

Monfared, Karlo January 2020 (has links)
Dysphagia is a serious eating disorder currently affecting around 100 thousand people in Sweden and it’s estimated that 1 in 10 people will develop some form of dysphagia during their lifetime around the world. The condition occurs mainly in elders and people who’ve suffered a stroke. The disorder prohibits proper swallowing of food, impairing the ability to close airways and let food enter the proper pathways. Patients with dysphagia have to eat grounded food in order to not suffer from malnutrition. The food is usually served in timbales which are sometimes decorated but might not look as appealing or realistic as one might think. The repetitive and unrealistic food creates further appetite loss which may lead to malnutrition. This is the case amongst many elderly in home care and the complications maybe very serious indeed, leading to organ dysfunction, hospitalization and eventually death. The current timbales made at the kitchens for elderly care in Helsingborg are punched with a tool in rectangular, circular shapes and often decorated. A solution would be to increase the aesthetics of the served timbales and make them realistically looking. 3D printing offers numerous new opportunities for food production and may very well set a standard in the future for producing aesthetically pleasing food. Silicone molds may also provide the same, if not better results at the time being at a fraction of the price, sufficing to revert any negative impacts of the current timbale appearance. In the hopes of proving both concepts the work will initially be focused on preparing a broccoli but also applying one of the concepts on a cinnamon bun providing additional application. This report presents the progress of designing a realistic 3D broccoli model, product development of a realistic broccoli food mold, 3D scanning, 3D food printing and a literature study. The designed model could not be printed due to the printing gel’s incapability of supporting complex structures. Instead master shapes created for shaping the food mold were scanned, sliced and printed. The same masters were used as means for a second food mold. Both food molds did manage to cast realistic shapes with a broccoli puré and of a soft gelatine suspension. Material alternatives were evaluated as well as manufacturing possibilities. The designed broccoli and a refined scanned broccoli were both offered for free as means for further research and development.
214

Elementární analýza sýrů s bílou plísní na povrchu / Elemental analysis of cheese with white mold on the surface

Pavlechová, Alžbeta January 2018 (has links)
This Master's thesis deals with elementary analysis of cheeses with white mold on the surface. Theoretical part describes general characteristics of cheese, classification of cheeses, their nutritional aspects and characteristics of cheeses with white mold on the surface. Large part is focused on description of mineral substances selected for analysis. At the end of the theoretical part, the Kjeldahl method and emission spectrometry with inductively coupled plasma (ICP-OES) were described. Experimental part deals with preparation of samples, approach of analysis and processing of measured results. Eleven samples of cheeses were used for analysis. These samples were from Czech Republic, France and Slovak Republic. Kjeldahl method was used to determine protein contents and ICP-OES was used for elemental analysis. The results were compared to each other and also with results from other studies. Subsequently, they were statistically processed and evaluated in the final part.
215

Návrh výrobní technologie vakuové lisovací formy / Production technology for a vacuum mold

Ponka, Ondřej January 2018 (has links)
The master thesis deals with the design and production of the mold for vacuum forming. Specifically, how the existing and new mold materials affect their design and, consequently, their production technology. The thesis contains a brief description of the principle of vacuum molding. Technological and design principles of designing molds. Furthermore, the realization of the solution variants and the simulation of their production. The solved variants are subsequently evaluated from a technical and economic point of view.
216

Kombinace numerické matematiky a neuronové sítě pro model predikce průvalu / Combination of numerical mathematics and neural network for the model of breakout prediction

Srba, Jan January 2019 (has links)
This thesis deals with creation of breakout prediction model implemented via artificial neural network in MATLAB, hence it contains theoretical description of artificial neural networks and also presents how the networks were used for the breakout prediction problem. In addition, models of heat conduction through the mold wall were created and used for generating neccesary data for proper training of artificial neural network. The thesis contains proper description of used numerical methods for solving the heat conduction problems. In the thesis are presented partial results and also results of testing created artificial neural network with usage of real data.
217

Manipulátor pro skládání slévárenských forem / Manipulator for folding molds

Borýsek, Lukáš January 2019 (has links)
The diploma thesis deals with the design of manipulator construction for folding two-part molds. In the thesis, an analysis of the current state of knowledge in the field of handling equipment and industrial robots is generally performed. Subsequently, the work introduces the current issue of handling equipment that is used in foundry. Furthermore, the work deals with the analysis of the manipulator construction, choosing the appropriate solution for the construction of its own handling equipment. Design solution is supported by computational message, 3D model and drawing documentation of selected nodes. The conclusion is devoted to the evaluation of work and practical recommendations.
218

Výroba součásti Dvojité koleno HTHT32/40 GI / Production of HTHT32 / 40 GI Double Elbow

Kříbala, Milan January 2020 (has links)
The diploma thesis deals with the design of an injection mold for manufacturing double elbow, which finds its use in the siphon assembly. The part will be made of polypropylene with the trade name Tatren HT 25 11. The production batch size is set at 100,000 units in 3 months. Firstly, the analysis of the part is done including a detailed specification of its function and criteria that must be met by the component. Furthermore, a suitable technology for the production of the part is chosen. The theory of injection molding and mold design is made on the basis of the chosen injection technology. Subsequently, in the practical part is made a complete design of injection mold including technological calculations and simulations. An injection molding machine is chosen for the proposed injection mold. The conclusion of the thesis consists of technical - economic evaluation of the production of double elbow.
219

Výroba rohové krytky / Production of corner cover

Hrdina, Vojtěch January 2020 (has links)
The project elaborated design of injection mould for production of corner cover, which serves to protect a reprobox from mechanical damage. The production possibilities were considered at the beginning. The injection molding technology was chosen from available technologies. The first part of the thesis is theoretic, plastics and injection molding are investigated. The choice of suitable polymer and the entire draft of mold is in the second part of thesis. The final mold is two-cavity with cold runner system. The technical and economic assessment of the proposal is carried out in the last part of thesis.
220

Charakterizace vybraných typů mléčných produktů / Characterisation of chosen types of dairy products

Musilová, Lenka January 2015 (has links)
The aim of this thesis was to design technology of production soft cheese with white mold on the surface in a pilot plant conditions using unpasteurized milk that comes from grazing cows. This way I wanted to be closer to the traditional cheese manufacturing technology, over which today dominates the industrial. Final cheeses were subjected to sensory analysis in order to determine their acceptability for ordinary consumers. Sensory evaluation was carried out by two committees: students and seniors. Between the two committiees were noticeable differences, however, both commissions at the conclusion assessed the cheese as „good”. This evaluation was mainly based on lower ratings of taste (flavor) of the samples, which were quite strong and unusual for Czech consumers.

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