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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.
1

Green Practices and Technologies for Sustainable Communities

Venneri, Rita 12 1900 (has links)
In 1987, Gro Harlem Bruntland formally introduced and popularized the concept of sustainable development. She defined it as being “development that meets the needs of the present without compromising the ability of future generations to meet their own” (World Commission on Environment and Development, 1987). Several cities, including the City of Hamilton have adopted certain environmental practices and technologies in an endeavor to improve their level of urban sustainability and achieve Bruntland’s goal of sustainable development. These practices include the support of individuals and city organizations that investigate new sustainable design alternatives for current infrastructure development. Such sustainable alternatives include the consumption of locally grown produce to avoid the detrimental effects associated with the transportation of imported foods via transport trucks, the installation of Rooftop Gardens as a viable option of ‘greening’ modern urban landscapes, and the construction of R-2000 Homes to reduce energy consumption rates and decrease the levels of harmful emissions that would normally be produced by conventional homes. The implications and/or benefits associated with any of the aforementioned designs were calculated using an environmental assessment tool developed by a professor at the University of British Columbia: Ecological Footprint (EF) Analysis. The final results of this study indicated that consuming locally grown produce, installing Rooftop Gardens, and living in R-2000 homes have the potential to enhance the state of the environment by improving air quality, reducing energy consumption, reducing water consumption, improving storm water retention, or by enhancing the biodiversity of a city’s landscape. However, in order to reap the benefits of any or all of the above ‘green’ practices or technologies and begin to establish a sustainable community, the fundamental doctrines that have influenced modern development practices, particularly those that place economic progress in front of the conservation and preservation of the environment, will need to be changed. / Thesis / Master of Engineering (ME)
2

Análise dos documentos de patentes correlacionados a tecnologias verdes depositados por universidades públicas brasileiras

Silva, Maguel Souza da 25 August 2016 (has links)
Submitted by Priscilla Araujo (priscilla@ibict.br) on 2017-06-19T19:17:05Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Maguel Souza da Silva - PPGCI - IBICT-UFRJ..pdf: 2110070 bytes, checksum: 01dca005cf43e2a29df2286bea857554 (MD5) / Made available in DSpace on 2017-06-19T19:17:05Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Maguel Souza da Silva - PPGCI - IBICT-UFRJ..pdf: 2110070 bytes, checksum: 01dca005cf43e2a29df2286bea857554 (MD5) Previous issue date: 2016-08-25 / A presente pesquisa identifica e analisa os documentos de patente correlacionados às tecnologias verdes depositados por 21 universidades públicas brasileiras no Instituto Nacional da Propriedade Industrial (INPI), entre 01 de janeiro de 2005 a 31 de dezembro de 2014, perfazendo o total de 294 documentos. Os dados foram coletados da base de patentes do INPI, durante o mês de setembro de 2015 e inseridos em uma planilha do Microsoft Excel, na qual foram analisadas as variáveis relacionadas aos documentos de patente (tipologia, distribuição dos documentos de patente por Região e Unidade Federativa brasileira, evolução temporal (data) dos depósitos, seções e subclasses da Classificação Internacional de Patentes); aos depositantes (universidades depositantes, distribuição de documentos por universidade e por campo das tecnologias verdes, rede de colaboração, família de patentes e interação entre universidade e empresa); e variáveis relativas aos inventores (número de inventores por documento, tipo de autoria e área de atuação por classe tecnológica). O resultado da pesquisa revelou a predominância de documentos do tipo patente de invenção. A região Sudeste e o estado de São Paulo se destacam como maiores depositantes. Identificou-se o aumento do número de depósitos nos anos de 2007 e de 2011. Observou-se que as classificações dos pedidos de patente correlatos às tecnologias verdes se concentram na seção C – Química e Metalurgia. A Universidade Estadual de Campinas (UNICAMP) aparece como a instituição com maior número de pedidos de patente depositados no INPI. Constatou-se que o maior número de documentos estava presente no campo de Gerenciamento de Resíduos, sendo a Universidade Federal de Minas Gerais (UFMG) a instituição que mais efetuou depósitos neste campo. A Universidade de São Paulo (USP) possui o maior número de colaboradores e a Universidade Federal do Rio de Janeiro (UFRJ) tem o maior número de depósitos efetuados em conjunto com empresas. O levantamento dos depósitos sob a perspectiva dos inventores revelou que 88% dos indivíduos constam como inventores relacionados a um único pedido de patente. Outro aspecto inerente aos inventores a ser apontado consiste no fato de que 9,8% das tecnologias presentes nos pedidos foram desenvolvidas individualmente; as demais (90,2%) são frutos da colaboração entre dois ou mais inventores. Buscou-se delinear o perfil das tecnologias verdes desenvolvidas por universidades públicas brasileiras, tendo como indicador o documento de patente. Ademais, espera-se que a presente pesquisa possa contribuir para a ampliação dos estudos sobre informação tecnológica no âmbito da Ciência da Informação. / This study identifies and analyzes the related patent documents to green technologies deposited by 21 Brazilian public universities at the Instituto Nacional da Propriedade Industrial (INPI) from 01/01/2005 to 31/12/2014, for a total of 294 documents. Data were collected in INPI patent basis during the month of September 2015 and entered into a Microsoft Excel spreadsheet in which we analyzed the variables related to patent documents (type, distribution of patent documents by Region and Federative Unit Brazilian, temporal evolution (date) of deposits and sections and subclasses of the International Patent Classification); to depositors (depositors universities, document distribution by university and field of green technologies, collaborative network, interaction between universities and companies and patent family); and variables related to the inventors (number of inventors by document type authored by technology class area of operation). The survey results revealed the predominance of documents of the type patent. The Southeast Region and the State of São Paulo stand out as larger depositors. It identified the increase in deposits in 2007 and 2011. It was observed that the classification of related patent applications for green technologies are concentrated in section C - Chemistry and Metallurgy. The Universidade Estadual de Campinas (UNICAMP) appears as the institution with the highest number of patent applications filed with the INPI. It was found that the largest number of documents was present in the waste management field, and the Universidade Federal de Minas Gerais (UFMG) the institution that made more deposits in this field. The Universidade de São Paulo (USP) has the largest number of employees and the Universidade Federal do Rio de Janeiro (UFRJ) has the largest number of deposits made in conjunction with companies. The withdrawal of deposits from the perspective of the inventors revealed that 88% of individuals listed as inventors related to a single patent application. Another aspect inherent to the inventors to be pointed out is the fact that 9.8% of these technologies in applications were developed individually; the others (90.2%) are the result of collaboration between two or more inventors. We sought to define the profile of green technologies developed by Brazilian public universities, with the indicator the patent document. Moreover, it is expected that this research will contribute to the expansion of studies on information technology in the context of Information Science.
3

Essays on Environmental NGOs and Clean Technologies Adoption

Urban, Ionut Bogdan 30 March 2021 (has links)
Chapter 1. We develop a model of NGO-firm partnerships. An NGO can share environmental expertise with one or two competing firms, and certify their 'clean' production, important for consumers with environmental concerns. The NGO may also obtain funds from a partner firm for an environmental project, important for consumers who derive project participation warm-glow. The NGO benefits from reduced environmental damage and project realization, while firms may gain or avoid loss of profitable custom. This model allows us to understand increasingly common partnerships between firms and NGOs as mutually beneficial in a competitive setting. 'Clean' production and/or the project may be independently viable on the market, supported by consumer preferences. A viable project can then support adoption of a non-viable 'clean' technology, leading to a 'cleaner' market. However, when 'clean' production is viable, we identify a 'dirty' production damage threshold below which the NGO prefers to obtain funds for a non-viable project and partners on production with only one firm, rather than forgo the project and partner on 'clean' production with both firms instead. Moreover, this damage threshold is increasing in consumers' environmental concern, and thus can generate counterintuitive situations: less environmental concern leads to a 'cleaner' market, whereas more concern leads to a 'dirtier' market. Chapter 2. Consumers choosing amongst horizontally-differentiated products (brands) that also embody some degree of an environmental attribute, suffer stigma if they make brown choices. The intensity of that stigmatization is declining in the fraction of other consumers making similarly brown decisions. It is common to suppose that people feeling such stigma would improve environmental outcomes. We show that while the threat of stigma makes it more likely that a consumer will choose the green option from a given menu, it can reduce the incentives for firms to offer green options in the first place. In an asymmetric duopoly setting social stigma can lower or increase the likelihood of clean technology adoption and in plausible circumstances drives the high-cost firm into a 'brown trap' or the low-cost firm into a 'green trap'. While increased competition reduces the 'green trap', it exacerbates the 'brown trap'. Chapter 3. The effect of warm-glow on number of NGOs and welfare is investigated within a charity market with ideologically differentiated public goods. In this setting ideology acts as a warm-glow multiplier on donations and high enough warm-glow can push welfare into negative territory — welfare would be higher if nobody donated. Under first-best we find that an optimal number of NGOs exists even though NGOs have no costs. Under free-entry we obtain the level of warm-glow that would induce the welfare-maximizing number of NGOs to enter. A social planner can determine donor population to behave overall as if they were experiencing the welfare-maximizing level of warm-glow, and thus optimize free-entry welfare, through one of two equivalent and revenue-neutral fiscal policies: by subsidizing/taxing donations either at the source, when the donors make them, or at the destination, when the NGOs receive them.
4

Air Pollution. In the City of Örebro

Bwanika, Daniel January 2000 (has links)
Air pollution and quality is one of the major problems in Örebro. Much research has been done to understand the impact of air pollution in urban societies and much more needs to be done in order to understand the implications of air quality impact on the region. Social structures in terms of environmental based planning for good air quality should focus on economic social costs need for new technologies and attainable health costs. Society can't survive without a healthy environment therefore understanding air quality and how new structures evolve for a practical human environmental interaction, is an absolute necessity for the well being and growth of Örebro region. The paper therefore, is an investigation into air quality impact on the existing structures in Örebro with air pollution as the major subject. It is based on critical evaluation of air pollution as derivative of a symbiotic human interaction with her environment and how contemporary planning structures should be attained. The paper throws light on the strategies being undertaken in Örebro region, in order to attain good health and cheap habitable environment in terms of technological, social and economic development.
5

Tecnologias verdes: mecanismo de efetivação da Política Nacional de Resíduos Sólidos aplicadas ao setor agrícola. / Green technologies: mechanisms of effectiveness the objectives of the National Policy of Solid Residue rural in activities such

Oliveira, Greice Kelly Lourenço Porfírio de 04 April 2017 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-11T11:14:09Z No. of bitstreams: 2 Dissertação - Greice Kelly Lourenço Porfírio de Oliveira - 2017.pdf: 1337783 bytes, checksum: 75d85b6e221e1a5bb9798a11d66c1afb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-11T11:14:22Z (GMT) No. of bitstreams: 2 Dissertação - Greice Kelly Lourenço Porfírio de Oliveira - 2017.pdf: 1337783 bytes, checksum: 75d85b6e221e1a5bb9798a11d66c1afb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-11T11:14:22Z (GMT). No. of bitstreams: 2 Dissertação - Greice Kelly Lourenço Porfírio de Oliveira - 2017.pdf: 1337783 bytes, checksum: 75d85b6e221e1a5bb9798a11d66c1afb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-04-04 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This present study has as its general theme, the study of environment friendly green technologies, which were applied to rural activities such as mechanisms of effectiveness pertaining to the objectives of the National Policy of Solid Residue adhering to the following line of study: Agro-Food Law, Territories and Development. The study will begin from law 12.305/10 denominated as National Policy of Solid Residue. In this bias, a reflection shall be made about the use of green technologies, such as techniques that are able to meet the objectives that were created by the National Policy of Solid Residue, in reference to incentives towards the creation of clean technology, treatment, reutilization and adequate disposal of solid residue in the agriculture sector; which are described in article 7 of the referred law, aiming towards harmony in the national and sustainable technological development. / A presente pesquisa tem como tema geral o estudo de tecnologias verdes ambientalmente amigáveis, aplicadas em atividades rurais como mecanismo de efetivação dos objetivos da Política Nacional de Resíduos Sólidos se enquadrando na linha de pesquisa Direito Agroalimentar, Territórios e Desenvolvimento. O estudo se realizará a partir da Lei 12.305/10 denominada de Política Nacional dos Resíduos Sólidos. Nesse viés, far-se-á uma reflexão acerca da utilização das Tecnologias Verdes como técnicas capazes de atender aos objetivos traçados pela Política Nacionais Resíduos Sólidos no que tange ao incentivo a criação de tecnologias limpas, bem como o tratamento, reutilização e descarte adequado de resíduos sólidos no setor agrícola, os quais são descritos no artigo 7º da referida Lei, visando à harmonia do desenvolvimento tecnológico sustentável nacional.
6

Obtención de fibra alimentaria a partir del subproducto de la industria citrícola, a través de la aplicación de diferentes tecnologías de extracción.

Pérez Pirotto, Claudia 17 January 2023 (has links)
Tesis por compendio / [ES] La presente tesis doctoral abarcó el desarrollo de un ingrediente a partir del subproducto de la industria citrícola. Se buscó obtener un ingrediente en polvo, con alto contenido de fibra soluble, que pudiera utilizarse en la formulación de productos. El trabajo se dividió en cuatro etapas. Tras la obtención del ingrediente por diferentes metodologías, en las primeras etapas se analizó su composición química y propiedades tecno funcionales. Posteriormente se realizó un ensayo de estabilidad del ingrediente tras su almacenamiento a diferentes actividades de agua. Finalmente, se evaluó la incorporación del ingrediente, como fuente de fibra, en la formulación de un flan; se estudió el efecto de la información sobre el origen de la fibra agregada en la respuesta del consumidor y el efecto de la incorporación de dicha fibra sobre las propiedades sensoriales del producto. Se ensayaron cuatro tecnologías no contaminantes para la extracción de fibra soluble: agua caliente, extrusión + agua caliente, jet cooker y jet cooker + agua caliente. El sobrenadante de la extracción se secó en "spray dryer" obteniendo un ingrediente en polvo. El contenido de fibra alimentaria de alto y bajo peso molecular fue analizado, junto con el contenido de azúcares simples y de compuestos bioactivos. El contenido de fibra total varió entre 10 y 20 gramos por 100 gramos de producto entre los tratamientos ensayados, siendo el proceso de extrusión + agua caliente el que mayor contenido de fibra presentó. Además, este tratamiento fue el que presentó menor contenido de azúcares y mayor contenido de compuestos bioactivos. En la segunda etapa se analizaron la capacidad espumante y estabilidad de la espuma, retención de aceite, solubilidad en agua, higroscopicidad, microestructura, temperatura de transición vítrea, color y reología de las soluciones. Se observaron diferentes grados de aglomeración en los polvos, que se relacionaron con la baja temperatura de transición vítrea de los ingredientes, fruto de sus componentes de bajo peso molecular. Aunque todas las soluciones formaron espumas, la del ingrediente obtenido por extrusión + agua caliente fue la más estable, lo que pudo deberse a su mayor viscosidad. En la tercera etapa se almacenaron los ingredientes obtenidos a diferentes actividades de agua durante 15 semanas, y una vez transcurrido el tiempo se modeló su isoterma de sorción. Además, se estudió la transición vítrea, junto con el contenido de compuestos bioactivos, color y textura. Los polvos no fueron estables en su estado inicial, debido al alto contenido de humedad que presentaban. Se observó pardeamiento a medida que aumenta la actividad de agua En la última etapa se evaluó la incorporación del ingrediente en la formulación de un flan. Se estudió el efecto de la información en la respuesta del consumidor y el efecto de su incorporación en las propiedades sensoriales. Se realizó una encuesta en España y Uruguay tomando como variables de estudio la intención de compra, y las percepciones de saludable y amigable con el medio ambiente. Se evaluaron tres categorías de producto diferentes (un producto listo para consumo, un polvo para preparar el postre en casa y un flan casero), variando la información ofrecida (origen de la fibra y un logo haciendo referencia a la sostenibilidad). El comportamiento de ambas poblaciones fue diferente en las tres variables de estudio, Para evaluar la incorporación del ingrediente en la formulación de un flan "fuente de fibra" (3% de contenido de fibra), se ensayaron diferentes porcentajes de sustitución de inulina (muestra control) del postre por el ingrediente de naranja obtenido a partir de la extrusión + agua caliente. La sustitución de un 30% del contenido total de fibra por el nuevo ingrediente logró un producto similar al control, sin descriptores de sabor no agradables y con una mejora en el brillo y la textura. / [CA] La investigació de la present tesi doctoral va abastar el desenvolupament d'un ingredient a partir del subproducte de la indústria citrícola. Es va buscar obtindre un ingredient en pols, amb alt contingut de fibra soluble, que poguera utilitzar-se en la formulació d'altres productes. Per a això el treball es va dividir en quatre etapes. Després de l'obtenció de l'ingredient per les diferents metodologies, en les primeres etapes es van analitzar la seua composició química i propietats tecno funcionals. Posteriorment es va feir un assaig d'estabilitat de l'ingredient després del seu emmagatzematge a diferents activitats d'aigua. Finalment, es va avaluar la incorporació de l'ingredient, com a font de fibra, en la formulació d'un flam; es va presentar l'efecte de la informació sobre l'origen de la fibra agregada en la resposta del consumidor i l'efecte de la incorporació d'aquesta fibra sobre les propietats sensorials del producte. Es van assajar quatre tecnologies no contaminants per a l'extracció de fibra soluble: aigua calenta, extrusió+aigua calenta, jet cooker i jet cooker+aigua calenta. El sobrenedant de l'extracció es va assecar en "spray dryer" obtenint un ingredient en pols. El contingut de fibra alimentària d'alt i baix pes molecular va ser analitzat juntament amb el contingut de sucres simples i de compostos bioactius. El contingut de fibra total va variar entre 10 i 20 grams per 100 grams de producte entre els tractaments assajats, sent el procés d'extrusió+aigua calenta el que major contingut de fibra va presentar. A més, aquest tractament va ser el que va presentar menor contingut de sucres i major contingut de compostos bioactius. En la segona etapa es van analitzar la capacitat espumant i estabilitat de l'espuma, retenció d'oli, solubilitat en aigua, higroscopicitat, microestructura, temperatura de transició vítria, color i reologia de les solucions. Es van observar diferents graus d'aglomeració en les pólvores, que es van relacionar amb la baixa temperatura de transició vítria dels ingredients, fruit dels seus components de baix pes molecular. Tot i que totes les solucions van a formar espumes, la de l'ingredient obtingut per extrusió+aigua calenta va ser la més estable, la qual cosa va poder deure's a la seua major viscositat. En la tercera etapa es van emmagatzemar els ingredients obtinguts a diferents activitats d'aigua durant 15 setmanes, i una vegada transcorregut el temps es va modelar la seua isoterma de sorció. A més, es va estudiar la transició vítria, juntament amb el contingut de compostos bioactius, color i textura. Les pólvores no van ser estables en el seu estat inicial, a causa de l'alt contingut d'humitat que presentaven. Es va observar pardejament a mesura que augmenta l'activitat d'aigua. En l'última etapa es va avaluar la incorporació de l'ingredient en la formulació d'un flam. Es va estudiar l'efecte d'informació sobre l'ingredient en la resposta del consumidor i l'efecte de la seua incorporació en les propietats sensorials. Es va fer una enquesta a Espanya i l'Uruguai prenent com a variables d'estudi la intenció de compra, i la percepció de saludable i amigable amb el medi ambient. Es van avaluar tres categories de producte diferents (un producte llest per a consum, una pols per a preparar les postres a casa i un flam casolà), variant la informació oferida (origen de la fibra i un logo fent referència a la sostenibilitat). El comportament de totes dues poblacions va ser diferent en les tres variables d'estudi. Per a avaluar la incorporació de l'ingredient en la formulació d'un flam "font de fibra" (3% de contingut de fibra), es van assajar diferents percentatges de substitució d'inulina (mostra control) de les postres per l'ingredient de taronja obtingut a partir de l'extrusió + aigua calenta. La substitució d'un 30% del contingut total de fibra pel nou ingredient va aconseguir un producte similar al control, sense descriptors de sabor no agradables, amb una millora en la lluentor i la textura / [EN] This thesis covered the development of an ingredient from the by-product of the citrus industry. The aim was to obtain a powdered ingredient, with high soluble fiber content, that could be used in the formulation of other products. The work was divided into four stages. After obtaining the ingredient by the different methodologies, in the first stages its chemical composition and techno-functional properties were analyzed. Afterwards, a stability test of the ingredient was carried out after storage at different water activities. Finally, theincorporation of the ingredient as a source of fiber, in the formulation of a flan was evaluated; the effect of information on the origin of the added fiber on consumer response and the effect of incorporating said fiber on the sensory properties of the product were studied. Four non-contaminant technologies for the extraction of soluble fiber were tested. These were hot water, extrusion + hot water, jet cooker, and jet cooker + hot water. The extraction supernatant was dried in a spray dryer to obtain a powdered ingredient. The content of high and low molecular weight dietary fiber and the content of simple sugars and bioactive compounds were analyzed. The total fiber content varied between 10 and 20 grams per 100 grams of product among the tested treatments, being the extrusion + hot water process the one with the highest fiber content. In addition, this treatment was the one with the lowest sugar content and the highest content of bioactive compounds. In the second stage, the foaming capacity and stability, oil holding capacity, water solubility, hygroscopicity, microstructure, glass transition temperature, color and rheology of the solutions were analyzed. Different degrees of caking were observed in the powders, which were related to the low glass transition temperature of the ingredients, due to their low molecular weight components. Although all the solutions formed foams, the foam of the ingredient obtained by extrusion + hot water was the most stable, which could be due to its higher viscosity. In the third stage, the ingredients obtained were stored at different water activities for 15 weeks, and once the time had elapsed, their sorption isotherm was modeled. In addition, the glass transition was studied, along with the content of bioactive compounds, color, and texture. The powders were not stable in their initial state, due to their high moisture content. Browning was observed as the water activity increased. In the last stage, the incorporation of the ingredient in the formulation of a flan was evaluated. The effect of information about the ingredient on consumer response and the effect of its incorporation on the sensory properties of the dessert were studied. To evaluate the effect of information on consumer response, a survey was carried out in Spain and Uruguay, taking purchase intention and healthiness and environmental friendliness perceptions as study variables. Three different product categories were evaluated (a ready-to-eat product, a powder to prepare dessert at home and a homemade flan), varying the information offered (origin of the fiber and a logo referring to sustainability). The behavior of both populations was different in the three study variables. To evaluate the incorporation of the ingredient in the formulation of a "fiber source" (total fibre content 3%) flan, different percentages of substitution of inulin content (control sample) the total fiber content of the dessert by the orange ingredient obtained from extrusion + hot water were tested. The substitution of 30% of the total fiber content with the new ingredient achieved a product similar to the control, without unpleasant flavor descriptors and with an improvement in brightness and texture. / This work was supported by the National Innovation and Investigation Agency (ANII), Uruguay, under code POS_EXT_2018_1_154449. / Pérez Pirotto, C. (2022). Obtención de fibra alimentaria a partir del subproducto de la industria citrícola, a través de la aplicación de diferentes tecnologías de extracción [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/191431 / Compendio
7

Plasmon catalyst dispersed on carbonised pinecone for enhanced degradation of organic contaminants

Olalekan, Sanni Saheed 11 1900 (has links)
Ph. D. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Aromatic organic contaminants are difficult to biodegrade, and thus effective green technologies are required to remove these pollutants from the ecosystem. Tetracycline antibiotic, an organic water pollutant, can be degraded by heterogeneous photocatalysis using an appropriate catalyst, with capability in converting the visible light energy into active species. The thesis focused on silver nanoparticles anchored on silver bromide (Ag/AgBr) as a plasmonic catalyst dispersed on activated carbon (ACK), were used as a photocatalyst (AABR-ACK) in tetracycline removal. The aim is to develop a catalyst that is active in low intensity visible light, whilst the addition of activated carbon will increase the light absorption and separate the charge pairs, after the photocatalyst has been excited by the visible light. The activated carbons were derived from pinecone pyrolyzed in a microwave. The pinecone mass to potassium hydroxide impregnation ratio and microwave pyrolysis time influenced the activated carbon properties. An impregnation ratio of 2.24 and microwave pyrolysis time of 16 minutes at constant microwave power of 400 W yielded the activated carbon with the best-developed porous structure and electrochemical properties. This activated carbon was used during the optimisation of the Ag/AgBr activated carbon (AABR-ACK) catalysts preparation using a thermal polyol precipitation method and response surface methodology. The most active catalyst was the AABR-ACK 11 obtained by a preparation temperature of 140 ºC, time (17.50 minutes), mass of surfactant and activated carbon (0.26 g and 0.03 g) respectively. This catalyst had an ordered nanospheres morphology, reduced electron-hole recombination rate, better electrochemical properties and exhibited enhanced activity on the tetracycline antibiotic removal in comparison to other Ag/AgBr activated carbon catalysts. A percentage degradation of 92% was obtained in 180 minutes were obtained with the AABR-ACK 11 catalyst. The photocatalyst prepared using the best activated carbon derived from pinecone developed in this study was compared to photocatalysts prepared using commercial activated carbon and biochar. The Ag/AgBr activated carbon catalysts using pinecone-derived activated carbon degraded the tetracycline to 92%, which is significantly higher than the percentage degradations (80% and 74%) for the catalyst prepared using commercial activated carbon and biochar catalysts respectively. The higher activity of the Ag/AgBr activated carbon catalysts using pinecone-derived activated carbon was due to the conductive attributes of the catalyst support for accelerated transfer of photo-induced electrons. The Ag/AgBr activated carbon catalysts using pinecone- derived activated carbon also exhibited better performance on tetracycline removal when compared to photocatalysts reported in literature. Two catalyst preparation methods, thermal polyol and deposition precipitation, were compared. The thermal polyol method yielded a more active catalyst for the degradation of the tetracycline in comparison to the deposition precipitation method. The degradation reaction conditions such as pH, light intensity and degradation temperature influenced the rate of the reaction. The highest rate of degradation was obtained at a pH of seven, white light and 40 ºC temperature. The intermediate products formed because of hydroxylation, deamination, demethylation and dehydration during the photocatalytic degradation of tetracycline antibiotics were identified using liquid chromatography mass spectrometer. Quenching experiments with hydroxyl, hole, and superoxide anion species showed that the most important radical responsible for the tetracycline degradation was the superoxide anion radical.
8

Sustainable Construction Practices of Intentional Communities: a Pilot Investigation in Loudoun County, Virginia and Frederick County, Maryland

Shedd, Jason Lee 11 August 2012 (has links)
This project investigated the sustainability of homes within three intentional communities. Semi-structured interview and photographic walkthroughs examined the variability of architectural and technological approaches toward sustainability. These include: passive solar design, green roofs, radiant flooring, composting toilets, ground assist heat pumps, solar water heaters, multiamily units and modular construction. It was hypothesized that variation in sustainable construction is related to socioeconomic status and that economics would be a constraint. This project investigated whether communities were transmitting their practices to wider society, if individuals were copying vernacular architecture and if architectural practices followed individual beliefs regarding sustainability. It was found that the Internet is the main method of conveying these practices; that variability was tied less to individual beliefs than to the communities’ institutional documents; and that copying vernacular architecture was for aesthetics not sustainability. Intentional communities are good models for sustainable development, but knowledge transmission is limited.

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