Made available in DSpace on 2014-10-09T12:50:56Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:30Z (GMT). No. of bitstreams: 1 11106.pdf: 6970470 bytes, checksum: 75dd1652faa57785066487ced8605c9d (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:50:56Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:58:30Z (GMT). No. of bitstreams: 1 11106.pdf: 6970470 bytes, checksum: 75dd1652faa57785066487ced8605c9d (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Det finns många frågetecken kvar kring konsumtionsbeteende inom förhistoriska kulturer. Målet med denna studie var därför att studera och förbättra förståelsen av det arkeobotaniska materialet i ugnar gjorda för att torka sädeskorn och hur ugnarnas innehåll korrelerar med den växtbaserade matkonsumtionen, samt att försöka se potentiella samband mellan ugnarna, deponerade växtrester i gravar och de två mossliken Grauballemannen och Tollundmannens maginnehåll. De 14 ugnarna, belägna i Sydskandinavien och daterade till järnåldern, analyserades och jämfördes för att se hur deras innehåll förhåller sig både i tid och rum men även jämfört med det övriga åkerbruket från bronsåldern till medeltiden. Det arkeobotaniska fynden visade att i yngre bronsåldern odlades det Hordeum vulgare var. vulgare, vilket följdes av en period då Hordeum vulgare var. nudum odlades. Detta pågick till slutet av romersk järnålder då Hordeum vulgare var. vulgare igen blev den vanligaste grödan att odla. I slutet av järnåldern odlades både Avena sativa och Hordeum vulgare var. vulgare. Övriga sädeskorn som Triticum sp. och Secale cereale har även odlats, dock endast till en mindre grad enligt fynden från ugnarna. De arkeobotaniska fynden jämfördes sedan med den rådande bilden av matkulturen under järnåldern, vilket visar indikationer på att Chenopodium album, Fallopia convolvulus, Persicaria maculosa/lapathifolia, Plantago lanceolata, Poacea, Polygonum aviculare och Spergula arvensis troligen har konsumerats tillsammans med de funna sädeskornen. Flera av dessa påträffades i de samtliga analyserade fornlämningarna.  Jämförelseanalyser i dendrogram mellan gravarnas och ugnars makrofossila rester samt de båda mosslikens maginnehåll visade inga definitiva samband. Dock fanns det gravar som korrelerade relativt starkt med ugnarnas innehåll, möjligen på grund av dess stora fyndmaterial av makrofossil. Dessa kunde visa indikationer på mat och måltid har deponerats i gravar.

Thesis (MTech(Environmental Health)--Cape Peninsula University of Technology, 2011 / Coke ovens may occur in the aluminium, steel, graphite, electrical, and construction industries. In the work area coke-oven workers may be exposed to various chemical compounds. Polycyclic aromatic hydrocarbons (PAHs), as human carcinogen, are primary compounds in coke oven emissions (COEs) generated in the coking process. Coke oven workers are often exposed to PAHs and can lead to a variety of human diseases.The primary routes of potential human exposure to coke oven emissions are inhalation and dermal contact. Occupational exposure may occur during the production of coke from coal, or while using coke to extract metals from their ores to synthesize calcium carbide, or to manufacture graphite and electrodes. Workers at coking plants and coal tar production plants, as well as the residents surrounding these plants, have a high risk of possible exposure to coke oven emissions.It is known that coke production could be carcinogenic to humans (Group-1) by IARC. There has been sufficient epidemiological evidence suggesting an etiological link between carcinogenic polycyclic aromatic hydrocarbon (PAHs) exposure and lung cancer risk among coke-oven workers. Lung cancer among coke-oven workers has been classified as one of the eight prescribed occupational cancers in China, and its incidence rate was about 10 times that of the general population. Therefore, lung cancer of coke-oven workers is still a critical issue in the field of prevention and control of occupational cancers in China.This thesis explores the various exposure levels of workers to PAHs at a steel plant in China. The measurement will focus on the exposure difference of personal sampling among workers in selected job classifications given the job descriptions and the coking process. The Benxi Steel Industry in Liaoning province of China (BXSI) was selected as the research location. Liaoning province is in the North of China and the location of various heavy industries in China. The measurements will be done two separate coke ovens in Benxi Steel Industry. One new coke oven was built in the 90's last century (coke oven N) and the other older coke oven was built in the 1940's in last century (coke oven O). In this research, the total number of employees that were selected in the sample for both coke ovens are 64 samples included 54 coke oven exposure workers and 10 non-exposure administrative workers working at the plants.

A promising and novel solar concentrator design has been thoroughly investigated and optimised. A prototype concentrator based on this novel geometry was validated using ray tracing techniques. This ray tracing demonstrated the comparative performance of this novel concentrator in regards to equivalent parabolic dishes. The effect of mirror surface normal errors on performance was established using Monte-Carlo based ray tracing code, which agreed well with the optical performance of this prototype which was determined experimentally. A need for low-cost solar cookers to replace bio-mass worldwide was identified, and the concentrator design was then developed as a low-cost solar oven. Despite existing in some number, no current design is able to achieve high performance at low-cost. An industrial partner, Dytecna, was initially involved in the process of this development of the system as a solar cooker. In support of a field trial for the solar cooker developed with Dytecna, a detailed thermal model of the oven was developed. A low-cost lightmeter was constructed and calibrated in order to measure the direct normal irradiance during the field trial in Italy. Laboratory work provided baseline results for the heating of various thermal masses in the oven. The Italian field trials provided a wealth of feedback into the design of the system and many valuable results. The solar cooker was able to bring 0.75L of water to the boil in 33 minutes with an average heat throughput of 203W. Important benchmark results and practical experience of several competing receiver materials was obtained; further lab testing provided more accurate measurements of the receivers' performances. The experiences of the Italian field trial were fed back into the design of a subsequent prototype, intended for a much larger field trial in Tanzania. Improvements in the hotplate, receiver material, and the oven were all incorporated into the design. Additionally, the structure of the solar cooker was redesigned to incorporate a low-cost wooden construction. Supporting work was conducted for the month long trial in which 8 solar cookers would be distributed to families in Tanzania. The field trial in Tanzania provided a wealth of user feedback into the design. At the same time the new solar cooker exceeded previously established performances in Italy. The new design was able to provide an average of 246W of heat to 1kg of water, which was brought to boiling point in 25 minutes. This represents a heating efficiency of 66% compared to the incident solar flux on the hotplate. In response to findings during the Tanzanian trials, further laboratory work was conducted into establishing the reflectivities of low-cost candidate mirror materials. Throughout all phases of the project the design of the solar cooker was refined and improved with the goal of a solar cooker design that could reach price-point, performance, and usability standards which would ensure market success.

No description available.

Thesis (M. Tech. - Engineering: Electrical, Department Electronic Engineering, Faculty of Engineering and Technology)--Vaal University of Technology. / Curing of materials in order to obtain different properties has been a practice for many years. New developments in composite materials increase the need to control certain variables during the curing process. One very significant variable is temperature. Temperature control by itself is an old practice, however when the need for repeatedly controlling the process accurately over long periods of time arises, a system is required that outperforms normal manual control. One of the aspects within such a system that needs to be considered is the ability to replicate the temperatures within an oven which were originally used for a specific material’s curing profile. This means that a curing profile would need to be defined, saved for later and finally be interpreted correctly by the controlling system. Different control methods were simulated to enable the system to control the temperature which has been defined by literature. This dissertation introduces a variation on the standard control methods and shows improved results. Switching the oven on and off in order to increase or decrease internal oven temperature seems simple, but can cause switching devices to decrease their operational life span, if not designed carefully. A combination switch was introduced which harnesses the advantages of two very common switching devices to form an improved combination switch. Software for the personal computer environment, as well as software for the embedded environment were developed and formed a control system that produced acceptable results for temperature control. Accuracies of 98% and more were achieved and found to be acceptable according to standard engineering control practices. An accurate temperature profile controller was designed, simulated and built in order to control the temperature inside a specific curing oven which, in turn, determined the curing properties of specific materials. The overall results were satisfactory which lead to achieving the objectives outlined in this dissertation.

Murray cod Maccullochella peelii peelii is an iconic freshwater angling species that has suffered declines in abundance and is now listed as a nationally vulnerable species. Despite recognition of the need for biological knowledge to provide future management directions, little is known of its ecology. This thesis examines that ecology to provide new knowledge and recommendations for improved conservation management. (For complete abstract open document)

Made available in DSpace on 2014-12-17T14:17:54Z (GMT). No. of bitstreams: 1 AureaPMS_DISSERT.pdf: 2426110 bytes, checksum: 8679cb89ec2b1a9d200750245aa86d51 (MD5) Previous issue date: 2014-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The present study aimed to characterize the thermal profile of wood fired oven used by the red ceramic industry in Parelhas, in the Serid? region/RN, aiming to propose structural interventions that can contribute to increasing productivity and product quality, optimize wood consumption and mitigate existing losses during the burning process. The study was conducted at Cer?mica Esperan?a in the city of Parelhas -RN, Brazil, during the period from August 2012 to September 2013. Four treatments were performed with three replicates, ie, with, a total of 12 experimental units (burnings). In the first stage 4 treatments were performed with three replicates, totaling 12 experimental units (firings). In the second stage 2 treatments were performed with three replications, totaling 6 experimental units (firings). The physical characteristics of the wood were analyzed using standard NBR 11941 and NBR 7190 for basic density and moisture, respectively. The clay was used as a reference parameter for distinguishing treatments. For both the analysis and characterization was carried out using techniques of fluorescence X (XRF) rays, X-ray diffraction (XRD) analysis, particle size analysis (FA). In the first and second stages were monitored: the time during the firing process, the amount of wood used at each firing, the number of parts enfornadas for subsequent determination of the percentages of losses, but also product quality. To characterize the thermal profile of the oven, we measured the temperature at 15 points scored in the surface charge put into the oven. Measurements were taken every 30 minutes from preheat until the end of burning, using a pyrometer laser sight sighting from preheating until the end of burning. In the second step 12 metal cylinders distributed on the oven walls, and the cylinder end walls 8 of the furnace 2 and rollers on each side walls are installed equidistant to 17 cm from the soil and the surface 30 of the wall are installed. The cylinders distributed on the front were placed 50 cm above the furnace, and the base of the oven 20 cm distant from the ground. 10 also thermocouples were installed, and five thermocouples distributed 1.77 cm above the combustion chambers, and one thermocouple on each side, and three thermocouples in front of the oven. We carried out the measurements of the temperatures every 1 hour during the burning two hours in cooling the cylinders with a pyrometer and thermocouples for dattaloger. These were fixed with depth of 30 cm from the wall. After statistical analysis it was found that: the thermal profile of the furnace surface and at different heights was heterogeneous; and the ranges of density and moisture content of wood are within recommended for use as an energy source standards. We conclude that even at low temperatures reached during firing there was a significant production of good quality products, this is due to high concentrations of iron oxide and potassium oxide found in clay, which lowers the melting point of the piece. The average burn time for each step varied 650-2100 minutes wood consumption was on average 20 m3, product quality was on average 16% of first quality, 70% second, third and 5% to 10% loss . The distance between the wire and the surface of the oven was a significant parameter for all treatments, but with different variations, meaning that the wire should not be so generic and unique form, used as a criterion for completion of the burn process. The central part of the furnace was the area that reached higher temperature, and in a unified manner, with the highest concentration of top quality products. The ideal temperature curve, which provided the highest quality of ceramic products was achieved in the central part of the furnace / O presente trabalho teve como objetivo geral caracterizar o perfil t?rmico de fornos tipo caipira utilizados pelo setor de cer?mica vermelha em Parelhas, na regi?o do Serid?/RN, visando propor interven??es que possam colaborar para aumentar a produtividade, a qualidade dos produtos, otimizar o consumo de madeira e mitigar as perdas existentes durante o processo de queima. O trabalho foi desenvolvido em duas etapas, entre agosto de 2012 e setembro de 2013, na Cer?mica Esperan?a localizada na cidade de Parelhas-RN, Brasil. Na primeira etapa foram realizados 4 tratamentos, com tr?s repeti??es, totalizando 12 unidades experimentais (queimas). Na segunda etapa foram realizados 2 tratamentos, com tr?s repeti??es, totalizando 6 unidades experimentais (queimas). Foram analisadas as caracter?sticas f?sicas da madeira utilizando-se norma NBR 11941 E NBR 7190 para densidade b?sica e umidade, respectivamente. O lote de argila foi o par?metro utilizado como refer?ncia para distinguir os tratamentos nas duas etapas. Para tanto a an?lise e caracteriza??o foi realizada a partir de t?cnicas de fluoresc?ncia por raios X (FRX), difra??o por raios X (DRX), an?lise granulom?trica (AG). Na primeira e segunda etapas foram monitorados: o tempo de queima durante todo o processo, a quantidade de madeira utilizada em cada queima, o n?mero de pe?as enfornadas para posterior determina??o das porcentagens de perdas, como tamb?m qualidade dos produtos. Para caracteriza??o do perfil t?rmico dos fornos na primeira etapa foram aferidas temperaturas em 15 pontos marcados na superf?cie da carga enfornada. Para avaliar a correla??o existente entre a dist?ncia da superf?cie da carga enfornada e o fio utilizado como par?metro de controle do processo, foram realizadas medi??es utilizando-se trena e, paralelamente, realizou-se as aferi??es das temperaturas a cada 30 minutos com pir?metro de mira laser a partir do pr?-aquecimento, at? o final da queima. Na segunda etapa foram instalados 12 cilindros met?licos distribu?dos nas paredes do forno, sendo 8 cilindros nas paredes frontais do forno e 2 cilindros em cada paredes laterais, foram instalados equidistantes, com 17 cm de dist?ncia do solo e 30 da parede da superf?cie. Os cilindros distribu?dos na parte frontal foram colocados a 50 cm da superf?cie do forno, e na base do forno distantes 20 cm do solo. Foram instalados tamb?m 10 termopares, sendo 5 termopares distribu?dos 1,77cm acima das c?maras de combust?o, e 1 termopar em cada lateral, e 3 termopares na parte frontal do forno. Realizou-se as aferi??es das temperaturas a cada 1 hora no per?odo de queima 2 horas no resfriamento com um pir?metro nos cilindros e um dattaloger para os termopares. Esses foram fixados com profundidade de 30 cm da parede. Ap?s an?lise estat?stica verificou-se que: o perfil t?rmico dos fornos na superf?cie e nas diferentes alturas foi heterog?neo; e as faixas de densidade e umidade da madeira est?o dentro dos padr?es recomendados para utiliza??o como fonte de energia. Conclui-se que mesmo com baixas temperaturas alcan?adas durante a queima houve uma produ??o significativa de produtos de boa qualidade, isso se deve a grande concentra??o de oxido de ferro e oxido de pot?ssio encontradas na argila, que baixa o ponto de fus?o das pe?as. O tempo m?dio de queima em cada etapa variou de 650 a 2100 minutos, consumo de madeira foi em m?dia 20 m3, qualidade dos produtos foi em m?dia 16 % de primeira qualidade,70% de segunda, 5 % de terceira e 10 % de perdas. A dist?ncia entre o fio e a superf?cie do forno foi um par?metro significativo para todos os tratamentos, mas com oscila??es diferenciadas, significando que o fio n?o deve ser o modo de forma gen?rico e exclusivo, utilizado como crit?rio para finaliza??o do processo de queimas. A parte central do forno foi ? ?rea que atingiu maior temperatura, e de maneira mais homog?nea, com maior concentra??o de produtos de primeira qualidade. A curva de temperatura ideal, que proporcionou a melhor qualidade dos produtos cer?micos foi atingida na parte central do forno

Made available in DSpace on 2014-12-17T14:58:25Z (GMT). No. of bitstreams: 1 WaldecioSAN.pdf: 2259202 bytes, checksum: 5cc6fb8a72468793d81d509b30ee2013 (MD5) Previous issue date: 2007-03-02 / The present work deals with an evaluation of the environmental impacts arised from a typical ceramics industry located in the Serid? region of Rio Grande do Norte State. That region contains the largest State s producing basin of red ceramics. The district of Parelhas stands out as the largest producing nucleus. The studied company is located in the rural zone of Parelhas, it was selected as study object because it possesses a great part of the representative characteristics of the Region s ceramics park as a whole. Impacts produced at the implantation and operation phases of the Company had been evaluated, being this last phase subdivided in stages of the productive process. Among found adverse impacts, they are distinguished: losses in air quality, undesirable noises, microclimatic alterations, impoverishment of the ground, elimination of the vegetal covering, agricultural exodus, crisis in cattle agriculture and, superficial and underground water contamination, beyond risks ocupational diseases and industrial accidents. The Leopold s interactive matrix, that summarizes results of the work, was presented in form of 15 (fifteen) tables that display impacts classified in qualitative and quantitative way. Totally, 175 (one hundred and seventy-five) significant impacts produced by this Company had been identified, being 114 (one hundred and fourteen) negative, 38 (thirty-eight) positive and 23 (twenty-three) among mixed, indefinite and inert ones. In the work, before the evaluation of impacts properly said, it was constructed a diagnostic table of the ambient situation at a previous moment to implantation of the Company, elaborated on basis of inferences and historical researches. It was proposed still, mitigative steps for adverse impacts identified, as also elaborated a program to accompaniment and observing that the fulfilment of indicated mitigative steps guarantees. The final part of the work contemplates conclusions and suggestions that aim to influence positively the presented sight in terms of environmental management / O presente trabalho trata de uma avalia??o de impactos ambientais gerados por uma ind?stria cer?mica t?pica da regi?o do Serid? do Rio Grande do Norte. Essa regi?o abriga a maior bacia produtora de cer?mica vermelha do Estado, destacando-se o munic?pio de Parelhas como maior n?cleo produtor. A empresa estudada localiza-se na zona rural do munic?pio de Parelhas, foi escolhida como objeto de estudo por reunir boa parte das caracter?sticas representativas do parque cer?mico da Regi?o como um todo. Foram avaliados os impactos produzidos nas fases de implanta??o e opera??o da Empresa, sendo esta ?ltima fase subdividida em etapas do processo produtivo. Entre os impactos adversos encontrados, destacam-se: perdas na qualidade do ar, ru?dos indesej?veis, altera??es no microclima, empobrecimento do solo, elimina??o da cobertura vegetal, ?xodo rural, crise na agricultura e pecu?ria, contamina??o de ?guas superficiais e subterr?neas, al?m de riscos de doen?as profissionais e acidentes de trabalho. A matriz interativa de Leopold, que resume os resultados do trabalho, foi apresentada na forma de 15 (quinze) tabelas que exp?em os impactos classificados de modo qualitativo e quantitativo. No total, foram identificados 175 (cento e setenta e cinco) impactos significativos produzidos por essa Empresa, sendo 114 (cento e quatorze) negativos, 38 (trinta e oito) positivos e outros 23 (vinte e tr?s) entre mistos, indefinidos e neutros. No trabalho, antes da avalia??o de impactos propriamente dita, foi constru?da uma tabela de diagn?stico da situa??o ambiental num momento anterior ? implanta??o da Empresa, elaborada com base em infer?ncias e pesquisas hist?ricas. Foram propostas ainda, medidas mitigadoras para impactos adversos identificados, como tamb?m elaborado um programa de acompanhamento e monitoramento que garanta o cumprimento das medidas mitigadoras indicadas. A parte final do trabalho contempla as conclus?es e sugest?es que visem influenciar positivamente o quadro apresentado em termos de gest?o ambiental