Hoy en día, la necesidad de monitorizar y controlar el medio ambiente es a cada vezmás importante debido al creciente nivel de gases tóxicos que provienen de la expansiónde las actividades industriales, amenazando así el medio ambiente y la salud humana. Eldesarrollo de la nano-tecnología ha permitido fabricar sensores de gases portables,altamente sensibles, selectivos, de bajo coste y de bajo consumo de potencia.Los nanotubos de carbono (NTC) están ganando un interés a cada vez más considerablepor parte de la comunidad científica debido a su geometría y morfología únicas y susexcelentes propiedades electrónicas, mecánicas, térmicas i ópticas. Esto hace de ellosunos candidatos prometedores para un amplio rango de aplicaciones como por ejemplonuevos sensores de gases con propiedades mejoradas. En este contexto, mediante lapresente tesis, se ha realizado un profundo estudio para explorar las propiedades dediferentes sensores basados en nano-materiales híbridos constituidos por nanotubos decarbono junto a otros materiales con el fin de detectar gases tóxicos de manera eficiente.El trabajo realizado consistió en el diseño, la fabricación, la caracterización, y laoptimización de nanosensores híbridos.Esta tesis fue financiada en el marco del proyecto Europeo "Nano2hybrids", cuyoobjetivo era de diseñar la interfaz de las nano-partículas del metal con los nanotubos decarbono a través del control de los defectos estructurales y químicos producidos por ladescarga de un plasma de radiofrecuencia y aplicarlo a la detección de gases. Elbenceno fue elegido como gas principal, debido a sus graves efectos tóxicos a niveles depocas ppb y también debido a la no existencia en el mercado de un detector de bajocoste para benceno. De hecho, no hay en el estado de la técnica, un sensor de gas quepuede detectar de forma selectiva este gas a nivel operativo de ppb y trabajando atemperatura ambiente. Así, el reto de esta tesis era obtener un sensor altamente sensible,selectivo y estable, portátil y de bajo coste para la detección de benceno.En este sentido, se estudiaron exhaustivamente diferentes materiales basados ennanotubos de carbono funcionalizados, decorados con nanopartículas de metal o biendecorados o mezclados con óxidos metálicos, en términos de su adecuación para ladetección de gases (por ejemplo, sus sensibilidad, selectividad, estabilidad, y elmecanismo de detección, etc.). En particular se estudió la detección de diferentes gasescomo (benceno (C6H6 ), monóxido de carbono (CO), dióxido de nitrógeno (NO2), eletileno (C2H4), el sulfuro de hidrógeno (H2S), amoníaco (NH3) y agua (H2O)). Nuestrastareas consistieron en investigar experimentalmente y teóricamente el efecto de lascondiciones de preparación de los materiales (p.e. el tratamiento con plasma, lanaturaleza del precursor y tamaño de las nanoparticulas de metales), fabricación delsensor (p.e., técnica de deposición, el efecto del tipo de metal del los electrodos delsensor), y de las condiciones de caracterización del sensor (p.e., temperatura deoperación, flujo de gas,) sobre las propiedades sensoras de los mismos. Todo ello hapermitido adquirir conocimientos, explicar los mecanismos de funcionamiento en elsensado de gases de los diferentes materiales investigados y con ello desarrollar unsensor de gases adecuado para la detección de benceno.Hemos encontrado que los materiales híbridos que consisten en nanotubos tratados conplasma de oxígeno y decorados con diferentes nanopartículas de metal, muestran unamayor capacitad de detección a temperatura ambiente respecto a los nanotubos decarbono en bruto o los funcionalizados sólo con plasma. Las propiedades interfacialesde los materiales híbridos resultantes pueden ser adaptadas, lo que ofrece una enormeflexibilidad para el ajuste de sus propiedades sensoras. Cuando se combinaron en unamatriz de micro-sensores que opera a temperatura ambiente, nanotubos decorados condiferentes metales, de forma que unos resulten sensibles al benceno y otros insensibles,esto permitió por primera vez la realización de un prototipo de bajo coste capaz dedetectar selectivamente y a temperatura ambiente el benceno presente a nivel de trazas(por debajo de 50 ppbs) en una mezcla de gases. El prototipo realizado presenta unostiempos de respuesta y de recuperación de 60 s y 10 minutos respectivamente además deuna buena estabilidad y reproducibilidad. Este prototipo se encuentra protegido por unapatente que ha sido licenciada a una compañía que se encargará de la comercializaciónindustrial del producto.In the last few years, there has been a growing demand for monitoring the environment,especially with the increasing concern by the release of toxic gases emitted by manmadeactivities. The development of nanotechnology has created a huge potential for buildinghighly sensitive, selective, low cost, and portable gas sensors with low powerconsumption.Nowadays, carbon nanotubes are receiving an intense interest from the scientificcommunity, due to their unique geometry, morphology, electronic, mechanical, thermaland optical properties, which make them a promising candidate for many industrialapplications including new gas sensors for the detection of toxic species. In this context,in this thesis a deep study is devoted to explore the sensing properties of differenthybrid nanomaterials based on carbon nanotubes for an efficient detection of toxicgases. The design, fabrication, characterization, and optimization of gas sensors usinghybrid materials have been carried out.This thesis was financially supported by the European project "Nano2hybrids", whichexploits the interface design of metal nanocluster-carbon nanotube hybrids via controlof structural and chemical defects in a plasma discharge, for designing gas sensors withsuperior performance. Benzene was chosen as the principal target gas due to its serioustoxic effects at low ppb levels and the fact that there are no reliable, low cost andselective benzene detectors in the market. In fact, no gas sensor able to selectivelydetect this gas at ppb levels and operating at ambient temperature has been reported upto now in the literature. So, the challenge of the project was to fabricate sensitive,highly selective, stable, portable, and low cost benzene gas sensor employing hybridnanomaterials.Herein, functionalized MWCNTs, metal decorated MWCNTs, and metal oxidedecorated MWCNTs or metal oxide and MWCNT mixtures were deeply investigated interms of their gas sensing performances (e.g, sensitivity, selectivity, stability, detectionmechanism,. etc) towards the detection of different gases (benzene (C6H6), carbonmonoxide (CO), nitrogen dioxide (NO2), ethylene (C2H4), hydrogen sulfide (H2S),ammonia (NH3), and water (H2O)). Our tasks were to investigate experimentally andtheoretically the effects of material preparation conditions (e.g., plasma treatment,nanocluster precursor and size), sensor fabrication (e.g., deposition technique,electrodes sensor metal), and sensor characterization conditions (e.g., operatingtemperature, gas flow) on the gas sensing properties of our devices, and to acquireknowledge in order to develop a selective benzene detector. Based on experimental andtheoretical results, different mechanisms for the interaction between gases and thehybrid materials tested have been proposed.We found that hybrid materials consisting of oxygen plasma treated multiwalled carbonnanotubes decorated with different metal nanoparticles showed room temperaturesensing capability. Responsiveness to gases of these hybrid materials was higher thanthat of pristine or plasma functionalized carbon nanotubes. Metal decoated CNTs can betailored for the recognition of different gases and vapors with different reactivities,which offers enormous flexibility for tuning the interfacial properties of the resultinghybrid materials and thus, of their sensing properties. When combined in a microsensorarray operating at room temperature, the use of benzene-sensitive and benzeneinsensitivemetal-decorated multiwalled carbon nanotubes, allowed for the first time theimplementation of a low cost detector prototype, which can selectively detect benzenewhen present at trace levels (below 50 ppb) in a gas mixture. Sensors present responseand recovery times of 60 s and 10 min respectively, good stability and reproducibility.This type of sensors are protected by a patent, and licensed to a company for industrialcommercialization.

This study shows an economically significant relation between a firm’s environmental performance and its cost of debt. Firms that have poor environmental performance will face future environmental liabilities related to compliance and clean-up costs due to increasingly strict environmental laws and regulations. Under current U.S. law, environmental liabilities can impair the value of fixed assets, as environmental claims often take precedence over the claims of creditors. Thus, future environmental liabilities are of particular concern to creditors. Previous accounting research has shown that a firm’s market value of equity is significantly affected by its environmental performance. However, the same has yet to be shown for a firm’s cost of debt capital. This study focuses on a sample of U.S. pulp and paper firms. The results imply that the market applies an ‘environmental risk’ premium of thirty-eight basis points to the cost of debt capital for the average public firm in the U.S. pulp and paper industry, based on its environmental performance. Environmental performance is measured using the annual toxic release inventory of the United States Environmental Protection Agency. It is a measure of the amount of toxic chemicals released to land, air and water by a firm’s operating facilities. This paper adds to the literature, providing evidence that environmental performance is a value relevant measure with regards to creditors. Thus, recent calls in the United States for greater cooperation between the Securities and Exchange Commission and the Environmental Protection Agency should be addressed. These calls are for the reporting, on a firm-wide basis, of quantifiable data that is already required by the Environmental Protection Agency but is not typically available in detail in firms’ reports to investors.

This study shows an economically significant relation between a firm’s environmental performance and its cost of debt. Firms that have poor environmental performance will face future environmental liabilities related to compliance and clean-up costs due to increasingly strict environmental laws and regulations. Under current U.S. law, environmental liabilities can impair the value of fixed assets, as environmental claims often take precedence over the claims of creditors. Thus, future environmental liabilities are of particular concern to creditors. Previous accounting research has shown that a firm’s market value of equity is significantly affected by its environmental performance. However, the same has yet to be shown for a firm’s cost of debt capital. This study focuses on a sample of U.S. pulp and paper firms. The results imply that the market applies an ‘environmental risk’ premium of thirty-eight basis points to the cost of debt capital for the average public firm in the U.S. pulp and paper industry, based on its environmental performance. Environmental performance is measured using the annual toxic release inventory of the United States Environmental Protection Agency. It is a measure of the amount of toxic chemicals released to land, air and water by a firm’s operating facilities. This paper adds to the literature, providing evidence that environmental performance is a value relevant measure with regards to creditors. Thus, recent calls in the United States for greater cooperation between the Securities and Exchange Commission and the Environmental Protection Agency should be addressed. These calls are for the reporting, on a firm-wide basis, of quantifiable data that is already required by the Environmental Protection Agency but is not typically available in detail in firms’ reports to investors.

Thesis (M.S.)--University of North Carolina at Wilmington, 2003. / Includes bibliographical references (leaves : [88]-96).

This thesis consists of three essays. The first essay, "Press and Leaks: Do Newspapers Reduce Toxic Emissions?", uses data on plant-level emissions in 2001-2009 from the Toxic Release Inventory of the US Environmental Protection Agency, coupled with data on location and content of newspapers, to investigate whether media coverage induces firms to reduce toxic emissions. The results show that an increase in Newspapers Density, that is the number of newspapers nearby the plant, raises the press coverage of the plant's toxic emissions and reduces the amount of these emissions. This association is larger in industries exposed to consumer pressure and in counties subjected to extreme negative health outcomes. The second essay, "Gender Quotas, Female Politicians and Public Expenditures: Quasi-Experimental Evidence", estimates the effect of gender quotas on the election of female politicians and on public finance decisions in Spanish municipalities, using a Before-After Regression Discontinuity Design. Gender quotas have increased the percentage of female candidates and also, but to a lower extent, the percentage of female councilors. The difference between the two effects is due to the strategic positioning of candidates within lists. The effect of quotas on the election of female mayors and on the size and composition of municipal expenditures is not statistically different from zero. The third essay, "Are attitudes endogenous to political regimes? Beliefs about working women in state-socialist countries", studies whether individual beliefs about gender roles are endogenous to political regimes, using a Difference-in-Differences analysis. The results suggest a significant difference in the evolution of attitudes towards gender roles between Europeans in state-socialist countries and other Europeans during the period 1947-1991. Central and Eastern Europeans who formed their attitudes during state socialism seem more likely to hold progressive beliefs regarding working women.

Thesis (doctoral)--Rijksuniversiteit Groningen, 1996. / Includes bibliographical references (p. [109]-119).

Submitted by RUTH HELENA GIANSANTE null (ruthhgster@gmail.com) on 2018-04-03T13:04:19Z No. of bitstreams: 1 RUTH_GIANSANTE_DISS_versão final (20DEZ2017) (5)6.pdf: 858614 bytes, checksum: 2838c4b704bfcc265b052ef9b29dcb67 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-03T18:23:48Z (GMT) No. of bitstreams: 1 giansante_rh_me_jabo.pdf: 858614 bytes, checksum: 2838c4b704bfcc265b052ef9b29dcb67 (MD5) / Made available in DSpace on 2018-04-03T18:23:48Z (GMT). No. of bitstreams: 1 giansante_rh_me_jabo.pdf: 858614 bytes, checksum: 2838c4b704bfcc265b052ef9b29dcb67 (MD5) Previous issue date: 2017-11-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Rizobactérias são excelentes candidatas à aplicação em processos de bioacumulação de elementos potencialmente tóxicos, pois desenvolveram mecanismos para a incorporação intracelular de uma ampla gama de íons. A sensibilidade e a capacidade de remoção de cádmio (Cd2+) de duas espécies de rizobactérias: Rizobium tropici (LBMP-C01) e Ensifer meliloti (LBMPC02), foram estudadas. A concentração mínima inibitória (CMI) das bactérias foi determinada pelo cultivo em meio contendo CdCl2.2H2O (0,025 a 4 mmol L-1). Foram realizados testes de viabilidade das células das duas estirpes na CMI e ensaios de bioacumulação com suspensões de células bacterianas nas doses de 10, 20 e 30 %(v/v) em solução contendo 100 mg L-1 de Cd2+. As estirpes LBMP-C01 e LBMP-C02 foram sensíveis a concentrações de Cd2+ superiores a 1,0 e 0,05 mmol L-1, respectivamente. As células de LBMP-C01 e LBMP-C02 apresentaram-se viáveis nas CMI 1,0 e 0,05 mmol L-1 Cd2+, respectivamente. A estirpe LBMP-C01 não removeu Cd2+ nos ensaios de bioacumulação e a estirpe LBMP-C02 foi capaz de remover 80 % deste íon em solução contendo 100 mg L-1 Cd2+, após 72 h de contato e 30 %(v/v) do bioacumulador. Os espectros de absorção molecular na região do infravermelho, de ambas as espécies estudadas praticamente não indicaram diferenças nos grupos funcionais presentes nas moléculas da biomassa celular. A observação por microscopia eletrônica de transmissão mostrou a presença de maior número de grânulos eletrodensos no citoplasma da estirpe de LBMP-C02 em relação à LBMP-C01 quando estas foram cultivadas com Cd2+. A estirpe LBMP-C02 foi a mais eficiente na remoção de Cd2+. A resistência a metais dessas duas bactérias envolve mecanismos diferentes. / Rhizobacteria are excellent candidates for use in the processes of bioaccumulation of potentially toxic elements because they have developed mechanisms for the intracellular uptake of a wide range of ions. Here, the sensitivity and capacity to remove cadmium (Cd2+) of two species of rhizobacteria, Rhizobium tropici (LBMP-C01) and Ensifer meliloti (LBMP-C02), were studied. The minimum inhibitory concentration (MIC) of the bacteria was determined by culturing them in medium containing CdCl2·2H2O (0.025 to 4 mmol L-1 ). Cell viability tests of the two strains were performed at MIC, and bioaccumulation assays were performed with 10, 20, and 30 %(v/v) bacterial cell suspensions in a Cd2+ solution 100 mg L-1 . Strains LBMP-C01 and LBMP-C02 were sensitive to Cd2+ concentrations above 1.0 and 0.05 mmol L-1 , respectively. LBMP-C01 and LBMP-C02 cells were viable at the MICs of Cd2+ solution 1.0 and 0.05 mmol L-1 , respectively. LBMP-C01 did not remove Cd2+ in the bioaccumulation assays, whereas LBMP-C02 removed 80 % of this ion in Cd2+ solution 100 mg L-1 , after 72 h of contact and 30 %(v/v) of the bioaccumulator. The infrared absorption spectra of both species did not indicate differences in the functional groups present in the molecules of the cell biomass. Transmission electron microscopy showed the presence of a larger number of electron-dense granules in the cytoplasm of LBMP-C02 compared to LBMP-C01 when they were cultured with Cd2+. The LBMP-C02 strain was the most efficient in the Cd2+ removal. The metal resistance of these two bacteria involves different mechanisms.

Children are sensitive to exposure of chemicals that may affect reproduction, cause allergies and cancer. Therefore it is important to strive for a toxin-free environment both at home and in preschools. The purpose of the study was to identify products in pre-school containing harmful chemicals. Furthermore, the purpose was to investigate how aware parents of the children in preschools are about chemicals in toys. The study included six preschools in Vindelns municipality and the parents of the children at these preschools. Inventories were made in the preschools to check which products could contain harmful chemicals and a questionnaire was distributed to the parents. The results of the inventories showed that most preschools have started removing plastic products but toys that can contain harmful substances still exist. The results of the surveys showed that 67% of parents do not know the concept of non-toxic preschool. This can be interpreted as the fact that the parents in question generally have limited knowledge about chemicals in toys and their impact on children's health. Parents need more information to become more aware of what products they have for their children and all the preschools in Vindelns municipality need to have a common plan to follow to continue to phase out products that may contain harmful substances in order to have a healthier environment for the children.

It is an ordinary practice to cover the areas after brown-coal mining with natural topsoil cover (topsoiling). Topsoiling is removal one topsoil from agricultural land, forest or area with vegetation and excavating to another place with poor organic matter content or in our case the brown-coal mining dumpsite. Advantages of topsoiling include higher organic matter and greater available water-holding capacity and nutrient content. Content of potentially toxic elements is very low. Ammonia nitrate (NH4NO3) extraction, BCR sequential analysis and aqua regia determination were applied in this study to prove that the proportion of bioavailable forms of PTE in reclaimed soils is also low. Amounts of potentially toxic elements were compared between different types of reclamation: an agricultural shown higher value for Pb and Cd, forestry has only one contaminant -- Cd. The research shows that toxicity of soil is low and has no dangerous influence for agricultural application.

The purpose of this study was to investigate how the upcoming EU-regulation regarding CMR-substances (Carcinogenic, Mutagenic or toxic for Reproduction) in textiles can be implemented in the supervision. The European Commission have used a simplified procedure provided by article 68(2) of REACH to restrict CMR-substances in textile that could be used by consumers. The parliament voted in favor on the 26th of April 2018 which has resulted in the ban coming into force by the end of 2020. The Swedish Chemical Agency therefore needs to know in which material or products these substances can be found. Data from various databases have been used and analyzed, then supplemented with reports. The substances have been categorized into functional chemical substances, auxiliary substances and chemical substances not intentionally added. Of these categories, functional chemical substances accounted for the greatest part. Classified azo dyes and carcinogenic amines were a big part of this category and the materials in which most chemicals were found were polyester and cotton. These are also the most frequently used textiles in the EU. It is therefore important to supervise these materials since the category functional chemical substances are found in highest concentrations in these materials. The supply chains are complex with a global span. To reduce hazardous chemicals in textile, it is important that the upstream information about which chemicals being used continues along the chain. Therefore, communication with suppliers and sub-suppliers is required. A regulation makes it easier for retailers to communicate their demands towards their suppliers.