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Processing and Properties of Particulate Reinforced Carbon Matrix CompositesShen, Jacklyn Dana 27 October 2022 (has links)
Carbonization of biomass is a type of pyrolysis that allows for the formation of byproducts that have applications in many other industries [1]. In the field of materials science concerned with environmental impact intersecting with desirable material properties and performance, the process of carbonization in particular with commonplace biomass such as food waste is of great interest. In this thesis, pistachio shell was used as the organic biomass of choice for carbonization, and reinforcement was provided by titanium powder. These two materials were milled together at two different compositions and milling times. Experimental conditions consisted of replicates of three bulk samples made from uniaxially pressed powder mixtures heat treated from 800 °C up to 1200 °C in increments of 100 °C. Heat treatment occurred in a tube furnace with a heating rate of 5 °C/min up to the heat treatment temperature, holding the temperature for 1 hour, then ramping back down to room temperature, all in an inert atmosphere. XRD was performed on heat treated samples before polishing, while optical microscopy and SEM were performed after mounting and polishing. TGA was performed on the milled powders, while hardness was performed on the heat treated bulk samples after mounting and polishing. Results obtained suggested that increasing heat treatment temperature and milling time decreased carbon matrix porosity. In addition, greater amounts of titanium seemed to result in increased porosity. However, at increased temperature, more surface cracking was observed, leading to the conclusion that an excessively high temperature is detrimental to mechanical properties. Finally, rutile TiO2 was formed as a result of the heat treatment process. In considering environmental impact, cost, and mechanical properties, a balance must be maintained between higher temperature processing, duration, milling time, and porosity present due to these factors. Future work includes further investigations into processing parameters and characterization such as XPS and abrasion testing. / Master of Science / Carbonization of organic materials such as wood or nut shells can be explained in short as a decomposition that occurs when those materials are heated up without allowing them access to oxygen as in a normal combustion like a fire. Because of that, carbonization can produce useful products and materials of interest to many. Adding titanium to pistachio shell powder, performing compaction and carbonization, then further heating up those samples, resulted in composite materials consisting of mostly carbon char and particles inside that improve the properties. After testing multiple experimental conditions and analyzing them using equipment such as X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), optical microscopes, Scanning Electron Microscopy (SEM)/Energy Dispersive Spectroscopy (EDS), and a hardness tester, some trends in properties and structure were observed. Generally, increasing heat treatment temperature and milling time will reduce porosity in the matrix. On the other hand, decreasing amount of Ti powder added seems to reduce porosity. However, too high of a heat treatment temperature seems to have a detrimental effect on the part manufactured (i.e. surface cracking). In addition, considering processing costs and time costs could discourage one from using a very high temperature to heat treat these samples. Therefore, it is important to balance amount of energy used to heat treat, time spent, and resulting porosity of the final product for its applications. Future work should be done to further determine the effects of processing parameters by making more samples to test the properties of. Other characterization techniques like X-Ray Photoelectron Spectroscopy (XPS) and abrasion testing could be good to determine the exact makeup of the particles in the composite as well as see the sample's performance in its intended application (i.e. brake pads).
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Etude de la conversion de la biomasse en energie par un procédé hydrothermal de carbonisation - Caractérisation des produits issus des grignons d'olive / Study of biomass conversion into energy by hydrothermal process of carbonization Characterization of products formed from olive pomaceMissaoui, Ayoub 29 November 2018 (has links)
La carbonisation hydrothermale (HTC) est un procédé de conversion en énergie de la biomasse dans l’eau sous critique (180-250°C) à faibles pressions (10-40 bars). Ce procédé conduit à la production d’un matériau solide carboné appelé "hydro-char". L’objectif de ce travail est d’optimiser le procédé HTC par l’étude des performances de l’hydro-char comme source d’énergie. La biomasse étudiée est un résidu d’extraction d’huile d’olive dénommé grignons d’olive constitués de peau, de pulpe et de noyau (taux d’humidité de 70%). Ces grignons d’origine marocaine ont été préalablement séchés (GOS). Au cours de l’HTC, la biomasse est décomposée via des réactions de déshydratation et de décarboxylation. Les hydro-chars sont moins humides et plus riches en carbone que les GOS. Aussi, ils s’appauvrissent en cendres en les transférant dans la phase liquide. Les hydro-chars ont un PCS plus élevé que celui de la tourbe et de lignite. Les résultats montrent que le rendement et les propriétés de l’hydro-char dépendent surtout de la température du procédé. Pour mieux analyser l’effet des conditions opératoires, l’approche des plans d’expériences a été appliquée pour optimiser et modéliser le procédé HTC. Grâce au plan de Doehlert, on peut relier les propriétés de l’hydro-char avec son rendement massique et son comportement thermique de combustion. La représentation des surfaces de réponses a permis de définir les zones de production d’hydro-char avec ses propriétés permettant d’orienter l’élaboration de l’hydro-char pour répondre aux critères d’une application prédéfinie. Le liquide issu de l’HTC des GOS montre une sensibilité à la variation des conditions opératoires. Le carbone soluble dans ce liquide lui donne un pouvoir polluant. Pour le diminuer, deux procédés de traitement ont été testés: l’évaporation et l’oxydation en voie humide. Les résultats ont montré que la quantité d’eau utilisée pour le traitement est le facteur le plus influent sur le bilan énergétique du procédé HTC. / Hydrothermal carbonization (HTC) allows pre-treating humid biomass in subcritical water (180-250°C) and at low pressures (10-40 bars) in the absence of air. This process produces a carbonaceous solid material called "hydro-char". The main aim of this work is to optimize the HTC process by studying the potential of hydro-char to produce energy. The studied biomass is a by-product of the olive oil industry called olive pomace containing water, residual oil, olive skin, olive pulp, and olive stones (with 70% moisture content). The moroccan olive pomace was first air-dried (DOP) and characterized. During the HTC process, the biomass is decomposed via dehydration and decarboxylation reactions. The obtained hydro-char has much less moisture and higher carbon contents than that of untreated DOP. Also, the hydro-char becomes poor in ashes by transferring them into the liquid phase. Hydro-chars have a higher HHV than that of peat and lignite. The results show that hydro-char mass yield and its properties depend on the process temperature especially. For a better analysis of the effect of operating conditions, a Design of Experiments Response Surface Methodology (DoE/RSM) approach was applied to optimize the HTC process. The DoE/RSM allows identifying a relationship between hydro-char properties and its mass yield and thermal combustion behavior. Response-surface plots show defined areas of production of hydro-char which allows tailoring hydro-char elaboration to a specific application. The process liquid from the HTC treatment of DOP shows a sensibility to operating conditions. The soluble carbon in the HTC liquid increases its polluting power and to decrease it two treatment process have been tested: evaporation and wet oxidation. Finally, the results show that the amount of water used for the hydrothermal treatment is the most influential factor on the energy balance of the HTC process.
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Solution synthesis and actuation of magnetic nanostructuresVach, Peter 18 February 2015 (has links)
Viele neue Technologien basieren auf Materialien die im Nanometerbereich strukturiert sind. Damit diese im großen Maßstab zur Anwendung gebracht werden können, werden Methoden benötigt solche nanostrukturierten Materialien kostengünstig zu produzieren. Magnetische Felder sind eine vielversprechende Möglichkeit die Anordnung von Nanostrukturen zu beeinflussen. In dieser Doktorarbeit wird eine Methode für die Herstellung magnetischer Nanostrukturen in Lösung präsentiert. Die Herstellungsmethode ist skalierbar und kostengünstig. Die synthetisierten Strukturen haben zufällige Formen und bewegen sich unter dem Einfluss eines externen rotierenden Magnetfelds im rechten Winkel zu der Ebene in der das Magnetfeld rotiert. Die dimensionslosen Geschwindigkeiten dieser zufällig geformten Propeller sind vergleichbar mit jenen früher publizierter helikaler Propeller. Das beobachtete Verhältnis zwischen Anregungsfrequenz und Propellergeschwindigkeit konnte mittels eines Drehmomentgleichgewichts verstanden werden. Dieses vertiefte Verständnis der Propellerbewegung ermöglichte eine theoretische Studie zur Kontrolle von Propellerschwärmen. Hierbei werden mehrere Propeller entlang frei wählbarer Bahnen gesteuert. Eine Kontrollstrategie wurde gefunden, welche die magnetische Feldstärke minimiert, die zum Erreichen einer vorgegebenen Genauigkeit nötig ist. Schließlich wurde das kollektive Verhalten von großen Mengen von magnetischen Propellern untersucht. Sowohl zufällig geformte als auch helikale Propeller bilden Zusammenballungen, die im dynamischen Gleichgewicht kreisförmig sind und langsam rotieren. Gleichförmig helikale Propeller ordnen sich in diesen Zusammenballungen hexagonal an. Der Vergleich zwischen Beobachtungen und Simulationen zeigte, dass hydrodynamische Interaktionen für die Bildung der Zusammenballungen nicht notwendig sind, aber dazu führen dass sich eine Randregion bildet, in der die Winkelgeschwindigkeit der Propeller erhöht ist. / New ways to cheaply produce and assemble useful micro- and nanostructures are needed to facilitate their deployment in novel technologies. Magnetic fields are a promising possibility to guide the assembly of nanostructures. This thesis presents a method to synthesize magnetic nanostructures in solution which can be actuated by external rotating magnetic fields. The synthesis method is scalable and can cheaply produce randomly shaped magnetic nanostructures in large quantities. The synthesized structures have random shapes and were observed to propel under the influence of an external magnetic field, perpendicular to the plane in which the external field is rotating. The random shapes move with dimensionless speeds that are comparable to those of previously published, nanofabricated propellers with controlled helical geometries. The observed relationship between actuating frequency and propulsion speed could be understood with a simple torque balance model. This improved understanding opened the door for a theoretical study on swarm control, i.e. the steering of several magnetic propellers along independent trajectories. A particular control strategy (critical control) was found, that minimizes the required magnetic field strength needed to achieve a certain control precision. Finally, the collective behavior of large numbers of propellers, moving upwards against gravity and towards a glass surface, was investigated. Both randomly shaped, as well as nanofabricated propellers were observed to form clusters which are circular and rotate slowly in dynamic equilibrium. The nanofabricated propellers displayed hexagonal ordering inside the clusters. Comparing the observed cluster dynamics to simulations revealed that hydrodynamic interactions between the propellers are not necessary for cluster formation, but lead to the formation of a boundary layer at the cluster edge, in which the angular velocity of the propellers is higher than in the rest of the rotating cluster.
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A ENERGIA LIMPA DO LIXO: A CARBONIZAÇÃO DE RESÍDUOS SÓLIDOS PARA PRODUÇÃO DE ENERGIA NA BUSCA DO DESENVOLVIMENTO URBANO SUSTENTÁVEL DA CIDADE DE GOIÂNIA.Berti, Elisa Regina Zanatta de Oliveira 25 March 2013 (has links)
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Previous issue date: 2013-03-25 / This thesis describes the problem of inadequate management of solid waste
and its harmful consequences to the whole society. It starts with the assumption
that the MSW lack proper destination, causing numerous environmental
problems. It thus explores the historical aspect, concept, classification and
characteristics of such wastes. Analyzes the National Solid Waste (Law
12.305/10), its history, object, instrument, prohibitions and policies, always in
the pursuit of sustainable waste management. Study the principles applicable to
solid waste within a national context, and according to international current
National Policy on Solid Waste. Describes also the project "Natureza Limpa"
and the steps in the carbonization of municipal solid waste as a sustainable and
environmentally friendly solution, capable of solving many of the problems
inherent in the improper disposal of solid waste. Finally, it analyzes the reality of
the current solid waste management at Goiânia/GO, and considering proposing
viable deployment of sustainable plant "Natureza Limpa" in the capital of Goiás.
The research used qualitative method literature, assuming the challenge of
linking theory and practice in the pursuit of an environmentally appropriate for
urban solid waste. / A presente dissertação descreve a problemática da gestão inadequada dos
resíduos sólidos e suas consequências nefastas a toda sociedade. Parte-se da
hipótese que os resíduos sólidos urbanos não possuem destinação adequada,
gerando inúmeros problemas socioambientais. Para tanto, aborda o aspecto
histórico, conceito, classificação e características de tais rejeitos. Analisa a
Política Nacional dos Resíduos Sólidos (Lei 12.305/10), seu histórico, objeto,
instrumentos, proibições e diretivas, sempre na busca da gestão sustentável
dos resíduos. Estuda os princípios aplicáveis aos resíduos sólidos dentro de
um contexto nacional, internacional e conforme a atual Política Nacional de
Resíduos Sólidos. Descreve, ainda, o projeto Natureza Limpa e as etapas na
carbonização dos resíduos sólidos urbanos, como uma solução
ambientalmente correta e sustentável, passível de solucionar boa parte dos
problemas inerentes ao descarte impróprio dos resíduos sólidos. Por fim,
analisa a realidade do atual gerenciamento dos resíduos sólidos de
Goiânia/GO, propondo e considerando viável a implantação da usina
sustentável Natureza Limpa na Capital goiana. A pesquisa utilizou o método
bibliográfico qualitativo, assumindo o desafio de articular a teoria e a prática na
busca de uma gestão ambientalmente adequada para os resíduos sólidos
urbanos.
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Matériaux carbonés par voie hydrothermale à partir de noyaux d'olive : étude du procédé, caractérisation des produits et applications / Carbon materials synthesis by Hydrothermal Carbonization of olive stones : Process and Product CharacterizationJeder, Asma 14 December 2017 (has links)
La carbonisation hydrothermale transforme les déchets municipaux (copeaux de bois, boues d'épuration, bagasse, feuilles…) en un produit solide appelé bio-charbon. Le produit hydrothermal connu sous le nom hydrochar est fréquemment utilisé comme carburant ou engrais, mais aussi il pourrait être converti en un produit à haute valeur ajoutée, à savoir le charbon actif. L‘objectif principal de cette thèse est d‘étudier la transformation de grignon d‘olive, précurseur lignocellulosique largement disponible en Tunisie et en pays méditerranéen, en hydrochar et en charbon actif. Dans cette étude, un réacteur discontinu de laboratoire a été conçu et construit. Les grignons d‘olive transformés en hydrochar ont été préparés à différentes sévérités et avec addition de sels, acide et ammoniac. Les hydrochars ont été caractérisés par plusieurs méthodes d‘analyse. L‘eau de traitement de la carbonisation hydrothermale a été analysée et les résultats montrent qu‘elle contient des composants à haute valeur ajoutée comme le furfural et le 5-HMF. Les charbons actifs ont été préparés à partir du hydrochar suivant des voies d‘activation physique (à l‘aide de l‘agent d‘activation CO2) et voies d‘activation chimique (par l‘agent d‘activation KOH). Les matériaux obtenus ont une surface spécifique élevée (1400 m2g-1) et aussi une chimie de surface riche en groupe fonctionnel. Les performances de ces charbons actifs dans l‘adsorption de molécules pharmaceutiques en phase liquide et de l‘hydrogène en phase gazeuse ont été examinées. Des capacités intéressantes ont été relevées pour les deux applications / Hydrothermal carbonization process uses green waste from municipalities (Wood chips, sewage sludge, bagasse, leaves …) to produce solid bio-coal. The solid HTC product known as hydrochar commonly used as a fuel or fertilizer but it could be converted also into high- value products like activated carbon. The principal purpose of this thesis is to study the conversion of olive stones, widely available lignocellulosic biomass in Tunisia and Mediterranean country, into hydrochar and then activated carbon. In this study, a laboratory scale batch reactor has been designed and built. The hydrothermally carbonized olive stones were prepared at different reaction severity and with addition of salts, acid or ammonia. All prepared hydrochar are characterized by different analysis methods. The HTC water was also analyzed and the results show that HTC-liquid contains high added value components such as furfural and 5-HMF. The hydrothermally carbonized olive stones were activated by both physical activation, using CO2 and chemical activation, using KOH. The materials had high surface area (as high as 1400 m2 g-1) and rich surface chemistry. The potential for pharmaceuticals (Ibuprofen and Metronidazole) and hydrogen adsorption were assessed for HTC-activated carbon and they showed good performance in both application
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Remoção de hormônios sexuais sintéticos por carbonização hidrotermal e por fungos de decomposição branca / Removal of synthetic sex hormones by hydrothermal carbonization and fungal decomposition whiteMorais, Ruiter Lima 29 August 2012 (has links)
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Previous issue date: 2012-08-29 / Contaminations of water and wastewater with endocrine disrupters from domestic and
industrial discharges have been proven in several regions of the planet. Among the endocrine
disruptors, the synthetic sex hormones cause great concern because the presence of phenolic
rings in their structures makes them stable and recalcitrant in the environment. In Goiás, the
presence of synthetic sex hormone concentrations of ethinylestradiol in mg.L-1 in the Meia
Ponte River, which goes accross the metropolitan area of Goiânia, was recently confirmed.
Studies have shown that concentrations of ng.L-1 can affect sexual differentiation and cause
serious damage to the reproductive system in fish and humans. Further, there are few
techniques that are proven of being effective on removing this type of substance. The aim of
this study was to evaluate the removal of synthetic sex hormones ethinylestradiol, gestodene,
and cyproterone acetate by the hydrothermal carbonization process and biological treatment
with fungi decomposing white Pycnoporus sanguineus and Trametes villosa. For this
purpose, solutions were prepared, individually and in combination with a concentration of 1,0
μg.mL-1 and pH correction into the range of 2-3 with solutions of phosphoric acid or citric
acid for treatment with hydrothermal carbonization. For the treatment with the fungus in
liquid culture medium and under the condition of stirring, a solution was prepared containing
all three hormones (ethinyl estradiol, cyproterone acetate and gestodene) in concentrations of
0,333 μg.mL-1. The carbonization treatments by the process of hydrothermal three hormones
with pH correction made with phosphoric acid and reaction time of 90 minutes showed
satisfactory removal of Ethinylestradiol and Gestodene, above 90%. Already in the individual
treatments, removal achieved was higher than 99% for all three hormones. The biological
treatment with Pycnoporus sanguineus and Trametes villosa show significant removal of
hormones and cyproterone acetate Ethinylestradiol above 99% and 78.9% for Gestodene for
both fungi. It was possible to notice that the presence of hormones increased the enzymatic
production of laccase, with peak production anticipated for the fungus Pycnoporus
sanguineus. The toxicity test with Artemia salina was observed that the solution with the
three hormones after carbonization hydrothermal treatment had fewer dead larvae of Artemia
salina, than the solution with hormones without treatment. In test germination of Allium cepa,
the solution treated with hormones hydrothermal carbonization showed the same germination
rate of the control group, however, less vigor of the shoots. As the control group, the solution
to the three hormones before treatment and after biological treatment, the 9.09%
concentration, showed no mortality of larvae of Artemia salina. These results show that both
the hydrothermal carbonization process as with the fungus Pycnoporus sanguineus and
Trametes villosa, show potential for future applications of synthetic sex hormones removal of
contaminated waters and effluents. / A contaminação de águas e esgotos com interferentes endócrinos proveniente de lançamentos
domésticos e industriais tem sido comprovada em diversas regiões do planeta. Entre os
interferentes endócrinos, os hormônios sexuais sintéticos causam grande preocupação, pois a
presença de anéis fenólicos nas suas estruturas, os tornam estáveis e recalcitrantes no meio
ambiente. Em Goiás, a presença do hormônio sexual sintético Etinilestradiol em
concentrações de μg.L-1 no Rio Meia Ponte, que corta a região metropolitana de Goiânia, foi
confirmada recentemente. Estudos mostraram que concentrações de ng.L-1 podem afetar a
diferenciação sexual e causar sérios danos ao sistema reprodutor em peixes e humanos.
Existem, ainda, poucas técnicas comprovadamente eficazes na remoção desse tipo de
substância. O objetivo desta pesquisa foi avaliar a remoção dos hormônios sexuais sintéticos
Etinilestradiol, Gestodeno e Acetato de Ciproterona através do processo de carbonização
hidrotermal e por enzimas oxidativas produzidas pelos fungos de decomposição branca
Pycnoporus sanguineus e Trametes villosa. Para tanto, foram preparadas soluções, individuais
e em mistura, com concentração de 1,0 μg.mL-1 e correção de pH para a faixa de 2-3, com
soluções de ácido fosfórico ou ácido cítrico, para o tratamento com carbonização hidrotermal.
Para o tratamento com os fungos, em meio de cultura líquido e sob a condição de agitação, foi
preparada uma solução contendo os três hormônios (Etinilestradiol, Acetato de Ciproterona e
Gestodeno) em concentração de 0,333 μg.mL-1. O tratamento pelo processo de carbonização
hidrotermal dos três hormônios com correção de pH feita com ácido fosfórico e tempo de
reação de 90 minutos apresentou resultados satisfatórios de remoção do Etinilestradiol e do
Gestodeno, acima de 90%. Já nos tratamentos individuais, a remoção alcançada foi maior que
99% para os três hormônios. O tratamento biológico com Pycnoporus sanguineus e Trametes
villosa apresentou resultados significativos de remoção dos hormônios Etinilestradiol e
Acetato de Ciproterona, acima de 99% e 78,9% para o Gestodeno, para ambos os fungos. Foi
possível notar ainda que a presença dos hormônios aumentou a produção enzimática de
Lacase, com pico de produção antecipado para o fungo Pycnoporus sanguineus. No teste de
toxicidade com Artemia salina observou-se que a solução com os três hormônios após o
tratamento com carbonização hidrotermal apresentou menor número de larvas mortas de
Artemia salina, do que a solução com os hormônios sem tratamento. No teste de germinação
de sementes de Allium cepa, a solução de hormônios tratada com carbonização hidrotermal
apresentou a mesma taxa de germinação do Grupo Controle, no entanto, menor vigor dos
brotos. Assim como o Grupo Controle, a solução com os três hormônios do antes do
tratamento e que após o tratamento biológico, a 9,09% de concentração, não apresentaram
mortalidade de larvas de Artemia salina. Esses resultados mostram que tanto o processo de
carbonização hidrotermal quanto o fúngico com Pycnoporus sanguineus e Trametes villosa,
apresentam potencial para futuras aplicações de remoção de hormônios sexuais sintéticos de
águas e efluentes contaminados.
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O efeito da carbonização de carcaças suínas do tempo de decomposição, na atratividade e diversidade de artrópodes de interesse forense / The effect of carbonization time on pig carcasses in thedecomposition time, attractiveness, abundance and diversity of arthropods of forensic interestProêncio, Vanessa Minhoto, 1980- 08 May 2011 (has links)
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Previous issue date: 2011 / Resumo: Para estimar o intervalo pós-morte (IPM) e determinar a provável causa mortis, a ciência forense pode utilizar várias técnicas, sendo um exemplo a avaliação das fases de decomposição de um corpo. Estas fases podem ser influenciadas por fatores extrínsecos como o clima (temperatura e umidade), injúrias no corpo e por fatores intrínsecos, isto é, condições fisiológicas e metabólicas do próprio organismo e também pelo modo como ocorreu a morte. Além desta técnica a ciência forense pode utilizar a Entomologia Forense, através do estudo da fauna cadavérica e sua possível sucessão, para auxiliar nas estimativas de IPM e determinar a causa mortis. O objetivo deste trabalho foi avaliar a influência da carbonização na evolução das fases de decomposição, atratividade e possível padrão sucessional dos insetos. Foram utilizadas quatro carcaças de suínos (Sus scrofa L.), sendo duas no período mais quente e úmido do ano e duas no período mais frio e seco. Para cada período uma carcaça foi queimada com gasolina até o nível 2 da escala de carbonização de Crow-Glassman, sem que fosse totalmente destruída, e a outra, utilizada como controle. As carcaças foram expostas em área natural de mata e protegidas por gaiolas para evitar a ação de predadores. Imagens das fases de decomposição foram obtidas diariamente. Insetos imaturos foram coletados das carcaças e levados ao laboratório para posterior emergência dos adultos, contagem e identificação. Insetos adultos foram coletados utilizando uma rede entomológica e identificados no laboratório. Embora em alguns momentos ambas as carcaças estivessem na mesma fase de decomposição, houve um retardo na decomposição da carcaça carbonizada de 3 dias a partir do 5º estágio de decomposição em relação à carcaça controle na estação quente. Na estação fria este fato foi observado a partir do 3º estágio de decomposição, com uma média de atraso de 9 dias, sugerindo que a carbonização influencia no tempo de decomposição. Foi observada uma sucessão entomológica em ambas as carcaças (carbonizada e controle), apresentando um padrão diferente em cada estação do ano e relacionado ao modo de morte. A colonização por artrópodes mostrou-se diferente em ambas as carcaças demonstrando a influência da carbonização na atratividade e frequência de insetos, sugerindo que a espécie Hemilucilia semidiaphana pode ser considerada indicador forense para modo de morte, para região de mata e na estimativa de IPM, enquanto que a espécie Hemilucilia segmentaria pode ser usada como indicador forense para região de mata e na estimativa de IPM. Foi observado também que Chrysomya albiceps pode ser usada para a estimativa de IPM. Chrysomya putoria e Lucilia eximia podem ser utilizadas como indicadores forenses para modo de morte e estimativa de IPM. Espécies da família Sarcophagidae podem ser usadas como indicadores forenses para modo de morte e para a estimativa de IPM. Temperatura e umidade relativa do ar exerceram influência na atividade dos insetos e sobre a decomposição, retardando ou acelerando o processo. Este estudo mostra a importância da causa mortis, dos fatores abióticos, do tempo de decomposição e da entomofauna para o auxílio na estimativa do IPM / Abstract: To estimate the postmortem interval (PMI) and to determine the probable cause of death in forensic science several techniques can be used, such as the assessment of the stage of decomposition of a body. These stages may be affected by extrinsic factors such as meteorological conditions (temperature and humidity) and injuries on the body, and by intrinsic factors related to physiological and metabolic conditions of the body, and also by the circumstances of death. In addition, the study of the cadaveric arthropod fauna as well as its successional pattern may help to estimate the PMI and to determine the cause of death. The aim of this study was to assess: 1) the influence of carbonization in the carcass decomposition process; 2) the attractiveness exerted by the burned carcass to necrophagous insects, and 3) the successional pattern of necrophagous insects in the carcasses. Four pig (Sus scrofa L.), carcasses were used in the experiments: two in the hot and humid period of the year (summer) and two during the cold and dry period of the year (winter). For each period, one carcass was burned with gasoline up to level 2 of Crow-Glassman scale (CGS) and another, was used as control. The carcasses were exposed in a natural wooded area, and placed in wire cages tp prevent the access of large scavengers. Pictures of the stages of decomposition were taken daily. Maggots were collected daily from the carcasses and brought to the laboratory and kept until adult emergence, counted and identified. Adults were collected by using an entomological net and identified in the laboratory. Although both, control and burned carcasses, were at the same decomposition stage, there was a delay in the decomposition of the burned carcass of 3 days from the 5th stage of decomposition in relation to the carcass control in the hot season. In this cold season was observed from the 3rd stage of decomposition, with an average delay of 9 days suggesting that the carbonization influence the time of decomposition. Insect sucession was observed in both carcasses (burned and control), showing a different pattern in each season and related to the mode of death.The colonization by arthropods was different in both carcasses, showing an influence of burning in the attractiveness and occurrence of some insects, suggesting that the blowfly Hemilucilia semidiaphana, may be used as forensic indicator for the mode of death, wooded areas and estimates of PMI, while Hemilucilia segmentaria may be used as forensic indicator for wooded areas and estimates of PMI. It was also observed that Chrysomya albiceps may be used as forensic indicator to estimates of PMI. Chrysomya putoria and Lucilia eximia may be used as forensic indicators for mode of death and estimates of IPM. Species of the family Sarcophagidae may be used as forensic indicators for mode of death and to estimate of PMI. Temperature and relative humidity also had an important influence on the decomposition process, slowing or accelerating the process on both substrates, as well as influencing the activity of insects. This study reported the important influence exerted by the cause of death and the abiotic factors, on the time of decay and on the insect fauna. Therefore, these factors have to be taken into consideration for the determination of the PMI / Mestrado / Parasitologia / Mestre em Parasitologia
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Polyphénols végétaux traités par voie humide : synthèse de carbones biosourcés hautement poreux et applications / Natural phenolic materials treated by a wet path : synthesis of bioresourced carbons highly porous and applicationsBraghiroli, Flavia Lega 01 December 2014 (has links)
Les ressources renouvelables sont considérées comme des alternatives durables, et parfois moins chères, aux matières premières d'origine pétrochimique. Dans cette thèse, on a utilisé du tanin provenant d’écorces de Mimosa comme précurseur de matériaux carbonés. La synthèse de ces nouveaux matériaux carbonés comprend un processus en deux étapes: la première étape est un traitement hydrothermal à des températures modérées, de 180 à 200°C, ce qui permet l'enrichissement en carbone ainsi que la fixation des hétéroatomes et la production de différentes morphologies: microsphères ou gels. La deuxième étape est une carbonisation à une température plus élevée, à savoir 900°C, ce qui permet d'augmenter la surface spécifique, la porosité ainsi que la conductivité électrique. La préparation d’un carbone poreux présentant des mésopores parfaitement définis en taille et dans leur organisation a été réalisée en associant le tanin, précurseur de carbone, à un tensio-actif structurant de la porosité, le copolymère Pluronic F127. Ces nouveaux matériaux carbonés ont été testés comme des électrodes de supercondensateur / Renewable resources are considered as sustainable, and sometimes cheaper, alternatives to substitute raw materials of petrochemical origin. We used tannins extracted from Mimosa barks. Tannin is an attractive precursor to synthesize new organic porous materials due to the presence of highly reactive phenolic molecules. The synthesis of these new carbon materials from tannin comprises a two-step process: the first step is a hydrothermal carbonization at moderate temperatures, 180-200°C, which allows obtaining a hydrochar, richer in carbon, and fixing other heteroatoms. These hydrochars present different morphologies as powder or gel. The second step is a carbonization at higher temperature (900°C), which allows increasing surface area (SBET), porosity as well as improving conductivity. The preparation of a porous carbon presenting mesopores perfectly defined in size and in their organization was realized by associating tannin, as carbon precursor, with a surfactant for porosity templating, the copolymer Pluronic F127. These new carbon materials were tested as electrodes of supercapacitor
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Korslimmat trä : Studie om delaminering vid brandexponering för olika brandskyddsbehandlingarEngvall, Vera, Zanasson, Zinar January 2022 (has links)
Purpose: This work is based on the problem with the product cross-laminated timber and its properties in the event of fire. The reason for the problem is the glue used in the product and the lack of requirements for adhesion at high temperatures. Due to this, there is a risk of delamination in the event of a fire, i.e. that the wooden slats that constitute the largest component in the CLT wood fall off during the course of the fire and contribute to extra energy. Method: The work is built up of two different methods, first a literature study and then an experiment. The literature study focuses on the National Board of Housing, Building and Planning's building regulations, the production of cross-laminated timber and what happens in the event of a fire. The experiment was carried out at Fågelbacken in Västerås, where help from the rescue service was available. The informative part of the report begins with a subject reference framework where the first part consists of information about the National Board of Housing, Building and Planning's requirements and ordinances that are based on the Planning and Building Act and the Planning and Building Ordinance. This study describes the experiment, everything from the application of the fire protection treatment to the design of the fire test. The materials included in the fire test are described and any certifications they hold are mentioned. The results section presents the results of the literature study and the fire test. Results: The four pieces of wood showed different results after fire, as three out of four showed cracks between the slats on the fire-affected surface. No piece of wood delaminated or had loose slats, however, the cracks are interpreted as meaning that the glue did not withstand the temperature that the fire generated, and melted. The depths of the carbon layer, on the other hand, were significantly protected by the fire protection treatment as there was a maximum difference of 7 mm between one of the fire protection-treated pieces of wood and the untreated piece of wood. The burning time of the fuel pool varied. The course of fire for the pieces that were treated with fire protection was strong with large flames and large, black smoke pillars. Conclusion: The conclusion of the thesis is that the fire protection treatment has a good effect on the depth of the carbon layer, which delays the risk of delamination. The fire protection treatment also has a good effect on the adhesive in some of the cases when no or few cracks between the slats were seen.
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Towards Water Resource Recovery Facilities : Environmentally Extended Techno-Economic Assessment of Emerging Sewage Sludge Management Technologies in Sweden / Mot anläggningar för återvinning av vattenresurser : Miljömässigt utökad teknisk-ekonomisk bedömning av nya tekniker för avloppsslamhantering i SverigeTibbetts, Harry January 2023 (has links)
Municipal sewage sludge (MSS) management varies widely between countries and legislative regimes. Within the European directive for sewage treatment France applies over half of MSS to arable land, while The Netherlands has banned the practice (Kelessidis et al, 2012). In Sweden, 34% of MSS is applied to agricultural lands; despite this, ocial government reports recommend banning the practice over pollution concerns, alongside the most common alternative of land reclamation (Ekane et al, 2020). This is the result of two decades of disagreement, complicated by dual perceptions of MSS as a valuable resource to be returned to the ecocycle vs an unsanitary waste product requiring careful disposal (Ekman Burgman, 2022). Previous studies have analyzed novel treatment technologies including multiple forms of phosphorus and nitrogen extraction from various stages of MSS treatment, but holistic system analyses are scarce (Bagheri et al 2023). Based on literature review and emerging technologies in Sweden, hydrothermal carbonisation (HTC) is identified as a keystone technology, and can be supported by secondary treatment via nitrogen stripping and phosphorus extraction from liquid and ash waste streams respectively. HTC is an anaerobic thermal treatment of wet organic waste resulting in solid hydrochar and liquid process water products. To address the lack of holistic assessments, an environmental and techno-economic assessment framework (ETEA) is applied to model three MSS treatment scenarios. Each scenario models treatment of MSS by anaerobic digestion (AD) and mechanical dewatering of digested sludge followed by: REF: A reference case of storage and arable land application of dewatered digested sludge (DDS) ALT1: DDS treatment by Oxypower HTC with Aqua2N nitrogen recovery from process and reject water. ALT2: The treatment described by ALT1, followed by hydrochar mono-incineration and Ash2Phos phosphorus extraction. ETEA is conducted in four stages using data collected from literature and public and private partners. Qualitative and quantitative process flow mapping defines the scenarios and models material and energy flows through the systems. An attributional comparative life cycle assessment (LCA) alongside techno-economic analysis (TEA) follows. The LCA has a gate to grave scope with a functional unit of one ton of total solids treated. Finally, results are evaluated using sensitivity and data uncertainty analysis to identify hotspots and knowledge gaps in the system. Results combining alternative scenarios based on current trends show the potential of emerging technologies to multiply WWTP nitrogen and phosphorus recovery by five and two times respectively, while simultaneously improving net energy recovery by three times. LCA results show reductions of greenhouse gas (GHG) emissions by between 60-70%. Considering emerging MSS technologies from a systems perspective provides critical context that can improve their economic viability. Combining intelligent systems design with these technologies, the models demonstrate how future MSS treatment can provide both good sanitation and recovery of nutrient and energy resources. Integration of these systems will accelerate the transition from wastewater treatment plants (WWTP) to water resource recovery facilities (WRRF). / Hanteringen av kommunalt avloppsslam (MSS) varierar kraftigt mellan länder och lagstiftande regimer. Inom det europeiska direktivet för avloppsrening tillämpar Frankrike över hälften av MSS på åkermark, medan Nederländerna har förbjudit detta (Kelessisdis et al, 2012). I Sverige tillämpas 34 % av MSS på jordbruksmark; Trots detta rekommenderar ociella regeringsrapporter att man förbjuder praxis på grund av föroreningsproblem, vid sidan av det vanligaste alternativet med landåtervinning (Ekane et al, 2020). Detta är resultatet av två decennier av oenighet, komplicerat av dubbla uppfattningar om MSS som en värdefull resurs som ska återföras till kretsloppet jämfört med en ohälsosam avfallsprodukt som kräver noggrann hantering (Ekman Burgman, 2022). Tidigare studier har analyserat nya reningstekniker inklusive flera former av fosfor- och kväveextraktion från olika stadier av MSS-behandling, men holistiska systemanalyser är få (Bagheri et al 2023). Baserat på litteraturgenomgång och framväxande teknologier i Sverige, identifieras hydrotermisk karbonisering (HTC) som en nyckelstensteknik, och kan stödjas av sekundär rening via kvävestrimning och fosforextraktion från flytande respektive askavfallsströmmar. HTC är en anaerob termisk behandling av vått organiskt avfall som resulterar i fast hydrochar och flytande processvattenprodukter. För att komma till rätta med bristen på holistiska bedömningar, tillämpas ett ramverk för miljö- och teknikekonomisk bedömning (ETEA) för att modellera tre MSS-behandlingsscenarier. Varje scenario modellerar behandling av MSS genom anaerob rötning (AD) och mekanisk avvattning av rötslam följt av: REF: Ett referensfall av lagring och applicering av åkermark av avvattnat rötslam (DDS) ALT1: DDS-behandling av Oxypower HTC med Aqua2N kväveåtervinning från process- och rejektvatten. Behandlingen som beskrivs av ALT1, följt av monoförbränning av kolväte och fosforextraktion av Ash2Phos. ETEA genomförs i fyra steg med hjälp av data som samlats in från litteratur och oentliga och privata partners. Kvalitativ och kvantitativ processflödeskartläggning definierar scenarierna och modellerar material- och energiflöden genom systemen. En attributionell jämförande livscykelanalys (LCA) tillsammans med teknisk-ekonomisk analys (TEA) följer. LCA har en grind till graven omfattning med en funktionell enhet på ett ton av totalt behandlat fast material. Slutligen utvärderas resultaten med hjälp av känslighets- och dataosäkerhetsanalys för att identifiera hotspots och kunskapsluckor i systemet. Resultat som kombinerar alternativa scenarier baserade på nuvarande trender visar potentialen hos framväxande teknologier för att multiplicera reningsverkens kväve- och fosforåtervinning med fem respektive två gånger, samtidigt som nettoenergiåtervinningen förbättras med tre gånger. LCA-resultat visar minskningar av växthusgasutsläpp (GHG) med mellan 60-70%. Att överväga framväxande MSS-teknologier ur ett systemperspektiv ger ett kritiskt sammanhang som kan förbättra deras ekonomiska bärkraft. Genom att kombinera intelligent systemdesign med dessa teknologier visar modellerna hur framtida MSS-behandling kan ge både bra sanitet och återvinning av närings- och energiresurser. Integration av dessa system kommer att påskynda övergången från reningsverk för avloppsvatten (WWTP) till anläggningar för återvinning av vattenresurser (WRRF).
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