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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.
101

Determinação do gradiente de pressão estática do ar para sistemas de compostagem por aeração forçada / Determination of static pressure gradient of air for composting system by forced aeration

Teixeira, Denis Leocádio 18 July 2014 (has links)
Made available in DSpace on 2015-03-26T13:23:59Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1263079 bytes, checksum: 4f8dcc7d9121a93cc4f882cd8390c608 (MD5) Previous issue date: 2014-07-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Although there equations and graphics in scientific literature to estimate the static pressure gradient of airflow through layers of grains and seeds, studies using organic waste submitted to composting treatment are scarce. The objective of this study was to adjust equations to estimate the static pressure gradient of airflow through layers of different organic residues. The waste used were chicken litter and as bulking agents and carbon source: sugarcane bagasse, sawdust and coffee husk which were mixed in the ratio of 0; 10; 20; 30 e 40% (volumetric basis), of chicken litter in relation to bulking agents, as well as mixture with C/N ratio of 25/1, which were submitted to composting process. Measurements of static pressure drop in layers of organic waste before and after the composting process, and in layers of material from the different proportions of chicken litter added to bulking agents, were performed using a prototype with specific airflow rates ranging from 0.02 to 0.13 m 3 s -1 m -2. The static pressure drop of airflow increased as a power of the material layer thickness. Static pressure gradient in layers of organic waste decrease with the composting process. Shedd, Hukill & Ives and Hunter models may be used to predict the static pressure gradient of air to be blown through the organic residues layers, however, the Shedd model was that which best represented the phenomenon studied. Lower values of static pressure gradient were obtained in layers without chicken litter and the higher values obtained in layers composed of mixture of chicken litter in proportion of 40%. Equations to estimate the static pressure gradient for different proportions of chicken litter may be clustered, yielding models that can explain the variation of pressure gradient for each bulking agent and carbon source. / Embora existam, na literatura científica, equações e gráficos para estimativa do gradiente de pressão estática do ar, quando forçado em camadas de grãos e sementes, são poucos os trabalhos realizados utilizando-se resíduos orgânicos submetidos ao tratamento por compostagem. Neste trabalho, teve-se por objetivo o ajuste de equações que possibilitassem a estimativa do gradiente de pressão estática do ar, quando insuflado em camadas de diferentes materiais orgânicos. Os resíduos utilizados foram a cama de frango e, como agentes estruturantes e fonte de carbono, o bagaço de cana-de-açúcar, a serragem de madeira e a palha de café, os quais foram misturados nas proporções de 0; 10; 20; 30 e 40% (base volumétrica) de cama de frango em relação aos agentes estruturantes, além de misturas com relação C/N de 25/1, as quais foram submetidas ao tratamento por compostagem. As medições da queda de pressão estática do ar, ao atravessar camadas de material orgânico, antes e depois de ter sido submetido ao tratamento por compostagem, e nas camadas de materiais provenientes das diferentes proporções de cama de frango adicionada aos agentes estruturantes, foram realizadas utilizando-se um protótipo, no qual o material foi submetido a vazões específicas de ar que variaram de 0,02 a 0,13 m 3 s -1 m -2 . A queda na pressão estática do ar aumentou de forma potencial com a espessura da camada de material. No que se refere ao decurso do processo de compostagem, este contribuiu para redução do gradiente de pressão estática do ar ao atravessar as camadas de material orgânico. Os modelos matemáticos de Shedd, Hukill & Ives e Hunter podem ser utilizados para predizer o gradiente de pressão estática do ar, ao ser insuflado em camadas de resíduos orgânicos, no entanto, o modelo de Shedd pode ser considerado, em termos estatísticos, o que melhor representou o fenômeno em estudo. Menores valores de gradientes de pressão estática do ar foram obtidos em camadas sem adição de cama de frango e os maiores obtidos nas camadas constituídas pela mistura com cama de frango na proporção de 40%. As equações obtidas para estimativa do gradiente de pressão estática do ar, para as diferentes proporções de cama de frango, podem ser agrupadas, originando modelos capazes de explicar a variação do gradiente de pressão para cada agente estruturante e fonte de carbono.
102

Avaliação da tratabilidade da cama de frango por processos aeróbios de compostagem visando sua reutilização / Evaluation of the composed material as a methodology for treating the poultry litter beyond its reutilization

Conceição, Priscila Soraia da 20 January 2012 (has links)
Made available in DSpace on 2015-03-26T13:28:07Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4583937 bytes, checksum: 1a468cd29ffe0a374735416f7a0a678b (MD5) Previous issue date: 2012-01-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The reutilization of poultry litter is an alternative way that producers found to deal with the high cost of the materials used to cover the floor on their farms. To reuse this poultry litter, it has to suffer changes on its physical, chemical and biological characteristics, perhaps compromising the process of chicken growth. To make it safe, is required that the producer treats this material; for example reducing the biological load and promoting ammonia to be released. With this present work, as the main focus, it s pursued the evaluation of the composed material as a methodology for treating the poultry litter beyond its reutilization. All the experiments were conducted at Laboratório de Engenharia Sanitária e Ambiental , regarding to the Civil Engineering Department, at Universidade Federal de Viçosa. It was made in four experiments. Experiment 1 was done by assembling a windrow of poultry litter, aerated, with fans cycles. During experiment 2, was compared the efficiency of different methods of composed materials applied at the treatment of the poultry litter in order to reutilize it, using one windrow poultry litter and two overturning cells; was also evaluated its influence on the substratum maker of the poultry litter on this process. On experiment 3, was evaluated the decay of nitrogen, on its normal and ammoniac forms, still using the windrow system. On experiment 4, was possible to determine the amount of volatile ammonia from the process of composed and the treated poultry litter. During the processes, temperature, water contamination, pH, solid contamination, organic carbon contamination, nitrogen and fecal contamination organisms were submitted to tests. The results show that, long cycles of aeration at the windrow system, make it harder to get the composed material done, because it make the material dry faster; the overturning cells show better efficiency reducing the biological load and releasing ammonia when it s compared to the windrow system. Summing up, the composed material obtained from the aerated windrow system, presents good efficiency in order to reduce the total and ammoniac nitrogen from the poultry litter. / A reutilização da cama de frango é uma alternativa encontrada pelos produtores como solução ao alto custo de aquisição de material para cobertura do piso. No reuso, a cama de frango sofre alterações em suas características físicas, químicas e biológicas, podendo comprometer o processo de criação de frangos. Para que o reuso seja seguro, é necessário que se faça um tratamento, a fim melhorar as características do resíduo, como reduzir a carga biológica e promover a liberação de amônia. Com a realização deste trabalho objetivou-se avaliar a compostagem como metodologia para o tratamento da cama de frango visando sua reutilização. Os experimentos foram conduzidos no Laboratório de Engenharia Sanitária e Ambiental, do Departamento de Engenharia Civil, da Universidade Federal de Viçosa. Foram montados quatro experimentos. O Experimento 1 consistiu na montagem de uma leira estática de cama de frango, aerada com diferentes ciclos de funcionamento do ventilador. Durante o Experimento 2, comparou-se a eficiência de diferentes métodos de compostagem aplicados no tratamento da cama de frango visando sua reutilização, com a montagem de 1 leira estática aerada e 2 pilhas por reviramento, avaliou-se também a influência do substrato formador da cama de frango no processo. No Experimento 3, avaliou-se o decaimento do nitrogênio, em sua forma total e amoniacal, da cama de frango submetida ao processo de compostagem por leira aerada estática. No Experimento 4, determinou-se a quantidade de amônia volatilizada da cama de frango durante o processo de compostagem e da cama tratada. Durante os tratamentos, foram realizadas análises de temperatura, teor de água, pH, teor de sólidos, teor de carbono orgânico total, nitrogênio e de organismos indicadores de contaminação fecal. Os resultados mostraram que ciclos de aeração muito prolongados realizados em leiras estáticas aeradas dificultam a realização da compostagem, pois ressecam rapidamente o material; a compostagem realizada em pilhas reviradas apresenta melhor eficiência na redução da carga biológica e na promoção da liberação de amônia se comparada ao método de leiras estáticas aeradas; a compostagem realizada em leiras estáticas aeradas apresenta boa eficiência na redução de nitrogênio total e amoniacal da cama de frango.
103

Remo??o de nitrog?nio em biofiltros aerado e an?xico, com alto ?ndice de vazios e sem remo??o de lodo

Bezerra Filho, Weliton Freire 28 July 2011 (has links)
Made available in DSpace on 2014-12-17T15:03:27Z (GMT). No. of bitstreams: 1 WelitonFBF_DISSERT.pdf: 2010897 bytes, checksum: 9145c54f00922f08967d3beb644f5f73 (MD5) Previous issue date: 2011-07-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The improper disposal of nitrogen in receiving water courses causes problems such as toxicity to living beings through the consumption of oxygen to meet the nitrogen demand, eutrophication and nitrate contamination of aquifers. For this reason it is often necessary to be carried out complementary treatment of wastewater to eliminate or reduce the concentration of this compound in the wastewater. The objective of this study is to evaluate the biological removal of nitrogen compounds using submerged aerated and anoxic filters as post-treatment of an anaerobic system, with low cost and innovative technology, which in previous studies has shown high removal efficiency of organic matter and great potential biological nitrogen compounds removal. The simple design with perforated hoses for air distribution and filling with plastic parts proved to be very efficient in relation to organic matter removal and nitrification. The system presented, in the best stage, efficiency in converting ammonia to nitrate by 71%, and produced a final effluent concentration below 10 mg / L of NH3-N. In addition, carbon concentration was removed by 77%, producing final effluent with 24 mg/L COD. However, denitrification in anoxic filter was not effective even with the addition of an external carbon source. There was a reduction of up to 56% of nitrogen caused by the process of simultaneous nitrification and denitrification (SND). The high voids space presented by this type of support material coupled with direct aeration of the sludge, allows the respiration of biomass retained between the endogenous phase, increased cell retention time and sludge retention capacity, producing a final effluent with turbidity less than 5 UT and total suspended solids around 5.0 mg/L / A disposi??o inadequada do nitrog?nio em corpos receptores gera problemas como: toxicidade para seres vivos; consumo de oxig?nio do meio para atender a demanda nitrogenada; eutrofiza??o; e contamina??o dos aqu?feros por nitrato. Por esta raz?o ? muitas vezes necess?rio que seja realizado tratamento complementar dos esgotos para eliminar, ou reduzir, a concentra??o deste composto nas ?guas residu?rias. O objetivo deste trabalho ? avaliar a remo??o biol?gica dos compostos nitrogenados utilizando filtros aerados submersos como p?s-tratamento de um sistema anaer?bio, com tecnologia inovadora, de baixo custo, que em estudos anteriores demonstrou grande efici?ncia na remo??o de mat?ria org?nica carbon?cea e grande potencial na remo??o biol?gica de compostos nitrogenados. A forma simples como o sistema foi concebido, com mangueiras perfuradas para distribui??o do ar e preenchimento com pe?as pl?sticas - condu?te cortado - mostrou-se bastante eficiente em rela??o ? remo??o de mat?ria org?nica e na nitrifica??o. O sistema apresentou, na melhor fase, efici?ncia na convers?o de nitrog?nio amoniacal em nitrato de 71%, e produziu efluente final com concentra??o de N-NH3 inferior a 10 mg/L. Al?m disso, observou-se uma redu??o de 77% na concentra??o de carbono, produzindo efluente final com 24 mg/L de DQO. Contudo a desnitrifica??o no filtro an?xico n?o se mostrou eficiente mesmo com a adi??o de uma fonte externa de carbono. Mesmo assim observou-se redu??o de at? 56% do nitrog?nio causado pelo processo de Nitrifica??o e Desnitrifica??o Simult?neas (SND). O grande ?ndice de vazios apresentado por este tipo de material suporte aliado ? aera??o direta do lodo, permite que a respira??o da biomassa retida entre na fase end?gena, aumentado o tempo de reten??o celular e a capacidade de reten??o de lodo, produzindo um efluente final com turbidez inferior a 5 UT e SST em torno de 5,0 mg/L
104

Možnosti využití kameniva na bázi odpadní skleněné moučky v novodobých stavebních materiálech / Possibilities of utilization of aggregate based on glass powder in new building materials

Novák, Jakub January 2018 (has links)
The diploma thesis deals with the use of waste glass powder as an aggregate in thermal insulation plasters for AAC. In the theoretical part, the problem of thermal protection of buildings is discussed first. The production and properties of foamed glass are described. Then the research of plasters, their composition and properties was made. Thermal-insulating plasters are specified and their use has been proposed for thermal insulation of building structures. In the practical part, suitable formulations have been proposed in the form of dry plaster and mortar mixtures (SOMS). Test samples were prepared from them. The physical and mechanical properties were measured. These were compared with the requirements set by standards and technical regulations. To get closer to the behavior of plasters on real buildings an AAC wall was built. The individual recipes were applied on it. It was monitored working with plaster and how it held on the masonry. During ripening crack development was observed. Optimization calculation inculded these aspects and it determined the optimal recipe. All designed recipes can be used as a thermal-insulating plasters.
105

Gelový infuzní clonový systém pro dodatečnou hydroizolaci různých druhů zdiva s využitím druhotných surovin / Gel infusion screen system for additional waterproofing of various types of masonry with share of secondary raw materials

Melichar, Jindřich Unknown Date (has links)
Virtually any construction project in our climate zone is facing some form of moisture. Older and historical buildings are mostly affected by the negative impact of water. Previously, the additional reduction of the moisture was executed only by mechanical methods, pushing insulating sheets or breaking through and cutting of masonry. Over time chemical methods were also invented, which are compared to the mechanical considerably simpler and user friendly applications to statics of treated buildings, making them ideal for the treatment of historical buildings or buildings that would not bear significant disruption. The main principle of chemical methods of redevelopment of wet masonry is the application of special material into the line of drilled holes with a given pitch. Subsequent penetration of the grouting material is believed to intersect an arc of individual drill holes, and thus to create so-called grout curtain that prevents the accumulation of water above it. Injection material may also contain a proportion of secondary raw materials, thereby reducing the influence of the impact of production on the environment. Efficiency infusion materials in masonry affected by many factors, such as temperature, humidity, or the type of material treated. It is also an important factor to determine the effectiveness of the remediation of the material, proving its ability to penetrate the building material by identifying its presence in it.
106

Vývoj vysokohodnotného pórobetonu při využití alternativních zdrojů / Development of high quality autoclaved aerated concrete using alternative resources

Kostura, Patrik January 2019 (has links)
With the growing trend of construction, the demand for building materials is growing steadily. Porous concrete is widely used in the building industry, that makes efforts to discount production and simultaneously save the environment. The aim of this thesis is to develop high-quality porous concrete by using alternative raw materials as a substitute for silicate sand. As a possible substitute were chosen: Silica masonry, foundry sand and fireclay boulders. The influence of two key parameters - the specific surface (130, 240 and 350 m2·kg-1) and the amount of silica sand substitution (10, 30 and 50 %) were monitored. Two autoclaving modes (7 and 12 hours of isothermal durations at 190 ° C) were tested. Based on the physico-mechanical and mineralogical characteristics of the porous concrete composites was chosen the ideal surface area of 240 m2·kg-1 and time of isothermal endurance was determined at 7 hours (temperature 190 ° C, pressure 1,4 MPa). From the optimal intentions were created samples with a macroporous structure, using an aluminum powder. Physical-mechanical properties and microstructural analysis (XRD, SEM) were subsequently determined on the samples. Ideal recipes were proposed with 50% sand substitution of fireclay boulders and 10% substitution of foundry sand. This was due to a 10% higher compressive strenght and an increase of the coefficient of constructiveness, compared to the reference sample.
107

Komunitní centrum pro seniory / Community Center for Seniors

Fišarová, Jana January 2020 (has links)
The subject of my diploma thesis is a proposal of a new community center for seniors near Brno in the village Pravlov. The building is designed for 12 people in 11 separate housing units. The building is divided into three floors. On the ground floor there are civic amenities (doctor's office, hairdresser) and technical facilities (utility room, cleaning room, facilities for employees). On the second and third floors there are separate apartments 1 + 1 and 1 + kk. Vertical walls are made of aerated concrete blocks, horizontal structures are made of reinforced concrete monolithic ceiling structures. The vertical connection between the individual floors is created by a prefabricated staircase. The community center for seniors is covered by a vegetation roof and part of the building is covered by a flat roof. On the south side of the building is located balcony.
108

Novostavba polikliniky v Rousínově / Newly-built polyclinic in Rousínov

Galata, Jindřich January 2020 (has links)
The subject of this diploma thesis is design documentation for implementation of the construction applied on the newly-built polyclinic in Rousínov. The polyclinic is the detached one, placed in the flat building plot with adjacent parking lot. The whole building is solving continuity on the surrounding local roads and dispersion areas. Basement of this building serves primarily as technical facilities for properly working on this new building. For example it’s about storages, utility room, boiling room, mechanical room etc. The first above-ground floor, where is situated entrance in to the building, from the southeast, is placed pharmacy, medical transport service and the first one doctor’s surgery. In the other above-ground floors are placed another doctor’s surgeries every with different specialization and in the last floor is a section for managers of polyclinic. The building is designed as a cast-in-place concrete frame with infill walls from aerated concrete. This building is based on plain concrete foundation pads and in the middle of span is shear core. Horizontal structures are solved by point-supported slabs with periphery beam and roofing is solved by warm flat roof. Whole building is insulated with contact thermal insulation from non-flammable material.
109

Polyfunkční dům Olomouc / Multipurpose facility Olomouc

Ocelík, Tomáš January 2016 (has links)
This thesis is focused on designing a new multipurpose building with parts used for apartments, administration offices and a bar. The land, which the building is situated on, is located in the city of Olomouc. The structure consist of five above-ground floors and one underground floor, where a garage is designed. The vertical supporting construction are made of reinforced cast-in-place concrete columns, the horizontal of reinforced concrete cast-in-place boards, other vertical walls are made of sand-lime and aerated concrete blocks. The roof is warm flat.
110

Návrh technologie vodopropustných betonů / Technology design watertight concrete

Skřivánek, Michal January 2017 (has links)
My work describes technology design of pervious concrete. The theoretical part contains a research about this kind of concrete usually from foreign authors. In general, I focused on the composition of the PC, aggregate grading curve, behaviour of concrete in fresh state, storing and compaction of concrete. A critical part is the aggregate grading curve – it plays the main role in the final level of water permeability. Further, we will go through the real world scenarios where we can use this type of concrete and also through the associated drawbacks. A substantial part of this work is about development of water-permeability test. The practical part shows variety of recipes with a list of measured and observed characteristics (compressive strength, frost resistence and water-permeability). The conclusion includes evaluation of the results and suggestions for future development in this area.

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