Contamination of groundwater by petroleum-hydrocarbons is a serious environmental problem. Monitored natural attenuation (MNA) is a passive remedial approach to degrade and dissipate contaminants in groundwater. In this study, a full-scale natural bioremediation investigation was conducted at a gasoline spill site. Results show that the concentrations of major contaminants [benzene, toluene, ethylbenzene, and xylenes (BTEX)] dropped to below detection limit before they reached the downgradient monitor well. This indicates that natural biodegradation process was the major cause of the contaminant reduction. In this study, 1,2,4-trimethylbenzene (1,2,4-TMB) was used as tracer to calculate the biological decay rates of BTEX. The calculated biological first-order decay rates for ethylbenzene, m+p-xylene, toluene, benzene, and o-xylene were 1.5¡Ñ10-3, 1.2¡Ñ10-3, 7.0¡Ñ10-4, 6.7¡Ñ10-4, and 1.2¡Ñ10-4, respectively. Mann-Kendall test was applied to analyze the trend of contaminant variations. Results show that the S-value of four monitor wells (CT-4, CT-41, CT-42, and CT-7) were -0.52, -1.57, -0.52, and -1.22, respectively. The negative S values reveal that the all contaminants tended to decrease. This indicates that the hydrocarbon plume at this site is not expanding, and has been contained effectively by the natural attenuation mechanisms. Evidences for the occurrence of natural attenuation include the following: (1) depletion of dissolved oxygen, nitrate, and sulfate; (2) production of dissolved ferrous iron, sulfide, and CO2; (3) decreased BTEX concentrations and BTEX as carbon to TOC ratio along the transport path; (4) increased alkalinity and microbial species; (5) limited spreading of the BTEX plume; and (6) preferential removal of certain BTEX components along the transport path. Results also show that the biodegradation capacity (46.02 mg/L) for BTEX and 1,2,4-TMB was much higher than the detected contaminants within the plume. Results indicate that natural attenuation can effectively contain the plume, and biodegradation processes played an important role on contaminant removal.

Solar photovoltaic has become one of the potential solutions for current energy needs and for combating greenhouse gas emissions. The photovoltaics (PV) industry is booming, with a yearly growth rate well in excess of 30% over the last decade. This explosive growth has been driven by market development programs to accelerate the deployment of sustainable energy options and rapidly increasing fossil fuel prices. Currently, the PV market is based on silicon wafer solar cells (thick cells of around 150–300 μm made of crystalline silicon). This technology, classified as the first-generation of photovoltaic cells. The second generation of photovoltaic materials is based on the introduction of thin film layers of semiconductor materials. Unfortunately, the conversion efficiency of the current PV systems is low despite the lower manufacturing costs. Nevertheless, to achieve highly efficient silicon solar cell devices, the development of new high quality materials in terms of structure and electrical properties is a must to overcome the issues related to amorphous silicon (a -Si:H) degradation. Meanwhile, to remain competitive with the conventional energy sources, cost must be taken into consideration. Moreover, novel approaches combined with conventional mature silicon solar cell technology can boost the conventional efficiency and break its maximum limits. In our approach, we set to achieve efficient, stable and affordable silicon solar cell devices by focusing on the development of a new device made of epitaxial films. This new device is developed using new epitaxial growth phosphorous and/or boron doped layers at low processing temperature using plasma enhanced chemical vapor deposition (PECVD). The junction between the phosphorous or boron-doped epitaxial film of the device is formed between the film and the p or n-type crystalline silicon (c-Si) substrate, giving rise to (n epi-Si/p c-Si device or p epi-Si/n c-Si device), respectively. Different processing conditions have been fully characterized and deployed for the fabrication of different silicon solar cells architectures. The high quality epitaxial film (up to 400 nm) was used as an emitter for an efficient stable homojunction solar cell. Extensive analysis of the developed fine structure material, using high resolution transmission electron microscope (HRTEM), showed that hydrogen played a crucial role in the epitaxial growth of highly phosphorous doped silicon films. The main processing parameters that influenced the quality of the structure were; radio frequency (RF) power density, the processing chamber pressure, the substrate temperature, the gas flow rate used for deposition of silicon films, and hydrogen dilution. The best result, in terms of structure and electrical properties, was achieved at intermediate hydrogen dilution (HD) regime between 91 and 92% under optimized deposition conditions of the rest of the processing parameters. The conductivity and the carrier mobility values are good indicators of the electrical quality of the silicon (Si) film and can be used to investigate the structural quality indirectly. The electrical conductivity analyses using spreading resistance profile (SRP), through the detection of active carriers inside the developed films, are presented in details for the developed epitaxial film under the optimized processing conditions. Measurements of the active phosphorous dopant revealed that, the film has a very high active carrier concentration of an average of 5.0 x1019 cm-3 with a maximum value of 6.9 x 1019 cm-3 at the interface between substrate and the epitaxial film. The observed higher concentration of electrically active P atoms compared to the total phosphorus concentration indicates that more than half of dopants become incorporated into substitutional positions. Highly doping efficiency ηd of more than 50 % was calculated from both secondary ion mass spectroscopy (SIMS) and SRP analysis. A variety of proposed structures were fabricated and characterized on planar, textured, and under different deposition temperatures. Detailed studies of the photovoltaic properties of the fabricated devices were carried out using epitaxial silicon films. The results of these studies confirmed that the measured open circuit voltage (Voc) of the device ranged between 575 and 580 mV with good fill factor (FF) values in the range of 74-76 %. We applied the rapid thermal process (RTP) for a very short time (60 s) at moderate temperature of 750oC to enhance the photovoltaic properties of the fabricated device. The following results were achieved, the values of Voc, and the short circuit current (Isc) were 598 mV and 27.5 mA respectively, with a fill factor value of up to 76 % leading to an efficiency of 12.5 %. Efficiency enhancement by 13.06 % was achieved over the reference cell which was prepared without using RTP. Another way to increase the efficiency of the fabricated device is to reduce the reflections from its polished substrate. This was achieved by utilizing the light trapping technique that transforms the reflective polished surface into a pyramidical texturing using alkaline solutions. Further enhancements of both Voc and Isc were achieved with values of 612 mV and 31mA respectively, and a fill factor of 76 % leading to an increase in the efficiency by up to 13.8 %. A noticeable efficiency enhancement by ~20 % over the reference cell is reported for the developed devices on the textured surfaces. Moreover, the efficiency of the fabricated epitaxial silicon solar cells can be boosted by the deployment of silicon nanocrystals (Si NCs) on the top surface of the fabricated devices. In the course of this PhD research we found a way to achieve this by depositing a thin layer of Si NCs, embedded in amorphous silicon matrix, on top of the epitaxial film. Structural analysis of the deposited Si NCs was performed. It is shown from the HRTEM analysis that the developed Si NCs, are randomly distributed, have a spherical shape with a radius of approximately 2.5 nm, and are 10-20 nm apart in the amorphous silicon matrix. Based on the size of the developed Si NCs, the optical band gap was found to be in the region of 1.8-2.2 eV. Due to the incorporation of Si NCs layer a noticeable enhancement in the Isc was reported.

Contamination of groundwater by petroleum-hydrocarbons is a widespread environmental problem. Because the petroleum-hydrocarbon resulted plumes could be quite diffuse and widespread, some more economic approaches are desirable for groundwater remediation to provide for long-term control of contaminated groundwater. Monitored natural attenuation (MNA) has been considered as a passive remedial approach to degrade and dissipate contaminants in groundwater. In this study, a full-scale and detailed natural bioremediation investigation was conducted at a petroleum-hydrocarbon spill site in Kaohsiung County, Taiwan. In this natural attenuation study, the following tasks were conducted: (1) groundwater analysis; (2) evaluation of the occurrence of natural attenuation, (3) calculation of biodegradation capacity and natural attenuation rate calculation, (4) evaluation of the percent loss of hydrocarbons due to biodegradation processes by BIOSCREEN model, and (5) application of BIOPLUME III model for the development of remedial strategies. Results show that benzene, toluene, ethylbenzene, and xylene isomers (BTEX) concentrations dropped to below detection limit (BDL) before they reached the downgradient monitor well located 280 m from the spill location. A first-order decay model was applied for the natural attenuation rate calculation. Results reveal that natural biodegradation process was the major cause of the BTEX reduction among the natural attenuation mechanisms. Results from the groundwater analyses indicate that mixed anaerobic biodegradation patterns occurred between the source and mid-plume area, and the aerobic biodegradation dominated the mid and downgradient area. Approximately 74% of the BTEX removal was due to intrinsic biodegradation processes. The calculated natural attenuation rates for BTEX, methyl tert-butyl ether (MTBE), and 1,2,4-trimethylbenzene (1,2,4-TMB) were 0.13, 0.06, and 0.19 1/day, respectively. Evidence for the occurrence of natural attenuation was the decreased contaminant mass flux through the plume cross-sections along the transport path. Evidences for the occurrence of natural BTEX biodegradation included the following: (1) depletion of dissolved oxygen (DO) within the plume; (2) production of biodegradation by-products [Fe(II), CO2, and methane] within the plume; and (3) decreased BTEX concentrations and BTEX as carbon to TOC ratio along the transport path. The calculated biodegradation capacity (45 mg/L) at this site is much higher than the detected concentrations of petroleum-hydrocarbons (1.5 mg/L) within the most contaminated area inside the plume. Thus, natural biodegradation should be able to remove the contaminants effectively. Results suggest that natural attenuation mechanisms can effectively contain the plume and cause the significant removal of petroleum hydrocarbons. Moreover, pump-and-treat and air sparging systems are also feasible technologies to remediate contaminated groundwater at this site.

Vagal sensory afferent innervation corresponds to regulation of neurogenic inflammation in the airways. Capsaicin is mostly used for stimulation of sensory nerves that induce pain and inflammatory responses. It can specifically stimulate sensory afferent nerves, inducing neurogenic inflammation in the airways. According the past studies, we have found the right thoracic vagus nerve (RTVN) and right recurrent laryngeal nerve (RRLN); branches of right thoracic vagus trunk (RTVT) mediate different degree of neurogenic inflammation by intraenous injection of capsaicin (300 nmol/ml/kg). In order to investigate the innervation from the RTVN and RRLN of rat tracheobronchi and their involvement in plasma exudation, we injected 3 £gl of capsaicin (10 mg/ml) into RTVT and denervated the RRLN or RTVN and used India ink as tracer dye to label the leaky microvessels. Our observation indicated that injection of capsaicin into the RTVT coud induce obvious plasma exudation in trachea (area density of leaky blood vessels was about 22%), but plasma exudation was significantly decreased after denervation of RRLN. The left upper side of trachea was decreased by 77.6% and the right upper side decreased by 84.5%. This phenomenon was not caused by denervation of RTVN. The results suggest that vagal nerve innervation of upper trachea mostly came from the RLN. Otherwise, capsaicin injection into the RTVT also induced neurogenic inflammation in the larynx. Experimental denervation of both superior and recurrent laryngeal nerves resulted in a decrease of plasma extravasation by 84.98%. Denervation of either RTVN or RRLN also decreased the plasma extravasation in the larynx. The evidence suggest that sensory fibers in the superior laryngeal nerve, recurrent laryngeal nerve, and thoracic vagus nerve might come from the same population of vagal ganglion sensory neurons.

Solar photovoltaic has become one of the potential solutions for current energy needs and for combating greenhouse gas emissions. The photovoltaics (PV) industry is booming, with a yearly growth rate well in excess of 30% over the last decade. This explosive growth has been driven by market development programs to accelerate the deployment of sustainable energy options and rapidly increasing fossil fuel prices. Currently, the PV market is based on silicon wafer solar cells (thick cells of around 150–300 μm made of crystalline silicon). This technology, classified as the first-generation of photovoltaic cells. The second generation of photovoltaic materials is based on the introduction of thin film layers of semiconductor materials. Unfortunately, the conversion efficiency of the current PV systems is low despite the lower manufacturing costs. Nevertheless, to achieve highly efficient silicon solar cell devices, the development of new high quality materials in terms of structure and electrical properties is a must to overcome the issues related to amorphous silicon (a -Si:H) degradation. Meanwhile, to remain competitive with the conventional energy sources, cost must be taken into consideration. Moreover, novel approaches combined with conventional mature silicon solar cell technology can boost the conventional efficiency and break its maximum limits. In our approach, we set to achieve efficient, stable and affordable silicon solar cell devices by focusing on the development of a new device made of epitaxial films. This new device is developed using new epitaxial growth phosphorous and/or boron doped layers at low processing temperature using plasma enhanced chemical vapor deposition (PECVD). The junction between the phosphorous or boron-doped epitaxial film of the device is formed between the film and the p or n-type crystalline silicon (c-Si) substrate, giving rise to (n epi-Si/p c-Si device or p epi-Si/n c-Si device), respectively. Different processing conditions have been fully characterized and deployed for the fabrication of different silicon solar cells architectures. The high quality epitaxial film (up to 400 nm) was used as an emitter for an efficient stable homojunction solar cell. Extensive analysis of the developed fine structure material, using high resolution transmission electron microscope (HRTEM), showed that hydrogen played a crucial role in the epitaxial growth of highly phosphorous doped silicon films. The main processing parameters that influenced the quality of the structure were; radio frequency (RF) power density, the processing chamber pressure, the substrate temperature, the gas flow rate used for deposition of silicon films, and hydrogen dilution. The best result, in terms of structure and electrical properties, was achieved at intermediate hydrogen dilution (HD) regime between 91 and 92% under optimized deposition conditions of the rest of the processing parameters. The conductivity and the carrier mobility values are good indicators of the electrical quality of the silicon (Si) film and can be used to investigate the structural quality indirectly. The electrical conductivity analyses using spreading resistance profile (SRP), through the detection of active carriers inside the developed films, are presented in details for the developed epitaxial film under the optimized processing conditions. Measurements of the active phosphorous dopant revealed that, the film has a very high active carrier concentration of an average of 5.0 x1019 cm-3 with a maximum value of 6.9 x 1019 cm-3 at the interface between substrate and the epitaxial film. The observed higher concentration of electrically active P atoms compared to the total phosphorus concentration indicates that more than half of dopants become incorporated into substitutional positions. Highly doping efficiency ηd of more than 50 % was calculated from both secondary ion mass spectroscopy (SIMS) and SRP analysis. A variety of proposed structures were fabricated and characterized on planar, textured, and under different deposition temperatures. Detailed studies of the photovoltaic properties of the fabricated devices were carried out using epitaxial silicon films. The results of these studies confirmed that the measured open circuit voltage (Voc) of the device ranged between 575 and 580 mV with good fill factor (FF) values in the range of 74-76 %. We applied the rapid thermal process (RTP) for a very short time (60 s) at moderate temperature of 750oC to enhance the photovoltaic properties of the fabricated device. The following results were achieved, the values of Voc, and the short circuit current (Isc) were 598 mV and 27.5 mA respectively, with a fill factor value of up to 76 % leading to an efficiency of 12.5 %. Efficiency enhancement by 13.06 % was achieved over the reference cell which was prepared without using RTP. Another way to increase the efficiency of the fabricated device is to reduce the reflections from its polished substrate. This was achieved by utilizing the light trapping technique that transforms the reflective polished surface into a pyramidical texturing using alkaline solutions. Further enhancements of both Voc and Isc were achieved with values of 612 mV and 31mA respectively, and a fill factor of 76 % leading to an increase in the efficiency by up to 13.8 %. A noticeable efficiency enhancement by ~20 % over the reference cell is reported for the developed devices on the textured surfaces. Moreover, the efficiency of the fabricated epitaxial silicon solar cells can be boosted by the deployment of silicon nanocrystals (Si NCs) on the top surface of the fabricated devices. In the course of this PhD research we found a way to achieve this by depositing a thin layer of Si NCs, embedded in amorphous silicon matrix, on top of the epitaxial film. Structural analysis of the deposited Si NCs was performed. It is shown from the HRTEM analysis that the developed Si NCs, are randomly distributed, have a spherical shape with a radius of approximately 2.5 nm, and are 10-20 nm apart in the amorphous silicon matrix. Based on the size of the developed Si NCs, the optical band gap was found to be in the region of 1.8-2.2 eV. Due to the incorporation of Si NCs layer a noticeable enhancement in the Isc was reported.

The mechanism by which ionic lanthanum (La3+) increases and subsequently decreases spontaneous transmitter release was investigated by recording miniature endplate potentials (MEPPs) at frog neuromuscular junctions. Addition of tetrodotoxin and Co2+ delayed the onset of MEPP frequency increase but did not otherwise prevent the response. Dinitrophenol substantially reduced but did not eliminate the increase, whereas 3,4,5-trimethoxybenzoic acid8-(diethylamino) octyl ester (TMB-8) completely abolished it. Thus, La3+ does not act by depolarizing the terminal or by substituting for Ca2+ at transmitter release sites. Instead, it appears to enter the terminal through Na+ channels and promote Ca2+ release from intracellular organelles. The profound depletion of transmitter with time may be due to the high turnover of transmitter coupled with the inhibition of metabolic processes by La3+.

[pt] O objetivo da dissertação é analisar a dinâmica de aprendizagem organizacional (AO) relativa ao processo de elaboração da Norma Internacional de Responsabilidade Social (ISO 26000), segundo a perspectiva da complexidade social. No contexto da normalização internacional e à luz dos desafios estratégicos enfrentados pela ISO referentes à governança global, parte-se do pressuposto de que a abordagem da complexidade social de AO pode contribuir para uma melhor compreensão do papel da aprendizagem na formação de consenso em dois níveis: entre as diversas categorias de stakeholders e entre países. A metodologia de pesquisa compreende: (i) revisão bibliográfica e documental sobre normalização internacional; sistemas adaptativos complexos; e aprendizagem organizacional, com especial atenção para abordagens integradoras; (ii) descrição do processo de desenvolvimento da norma internacional ISO 26000; (iii) proposição de modelo conceitual que integra normalização internacional e aprendizagem organizacional, segundo a perspectiva da complexidade social; (iv) pesquisa survey junto a especialistas do Grupo de Trabalho ISO-TMB-WG SR e de seu comitê espelho brasileiro; e (v) estudo de caso de AO no processo de elaboração da Norma Internacional ISO 26000, com resultados da pesquisa survey. Esses resultados incluem: (i) a análise da dinâmica de AO relativa ao processo de elaboração da norma ISO 26000; (ii) relação dos principais fatores facilitadores de AO neste caso, considerando os dois níveis de análise; e (iii) recomendações endereçadas à ISO e à ABNT para futuros desenvolvimentos de normas internacionais em ambientes sociais complexos. / [en] The main objective of this dissertation is to analyze the learning dynamics and the specific learning mechanisms experimented by the different groups during the development process of ISO 26000 standard, through the lens of the social complexity perspective of organizational learning (OL). In the context of ISO 26000’s learning process, it was assumed that the social complexity perspective of organizational learning (OL) could be especially useful as it can improve the understanding of the role of learning in a double level of consensus – amongst stakeholders and across countries – in the light of the strategic challenges faced by ISO within the global governance arena. The research methodology comprises: (i) bibliographical and documental review on international standardization; social complex adaptive systems; organizational learning, with special attention to integrative approaches; (ii) review of the development process of ISO 26000 standard; (iii) design of a conceptual model that integrates the international standardization and organizational learning, through the lens of the social complexity perspective; (iv) development and application of a survey questionnaire to representatives of ISO-TMB-WG SR, including its Brazilian Mirror Committee; and (v) description of ISO 26000 study case. The main results can be summarized as follows: (i) learning dynamics analysis of the development process of ISO 26000 standard; (ii) list of main facilitating and constraining factors for OL in this case; and (iii) recommendations addressed to ISO regarding future international standardization processes in social complex environments.

[pt] O aumento da produção mundial de resíduos e a falta de programas de gestão adequados a estes resultam no descarte e disposição inadequadas, causando inúmeros impactos ambientais e afetando, inclusive, à saúde humana. Tais resíduos, por apresentarem alto poder calorífico, versatilidade e resistência, devem ser tratados como matéria prima pós-consumo e não como lixo, podendo ser utilizados de inúmeras formas. Uma delas é a reciclagem, um processo que apresenta nova utilização aos resíduos antes designados como lixo, gerando possibilidades de rentabilidade e emprego. A reciclagem tem grande importância na gestão social de um município, pois está ligada diretamente às classes de baixa renda. Tais processos têm crescido no Brasil, principalmente após a publicação da Política Nacional de Resíduos Sólidos (PNRS) - Lei n 12.305, que exige um plano de resíduos para cada município, incentivando a reciclagem e compostagem de lixo. Ainda assim, o problema persiste, devido à falta de programas de coleta seletiva, falta de incentivo aos recicladores e catadores, bem como descaso dos governos e da população. A probabilidade de melhoria é grande, porém demandará muito tempo e investimento. O tratamento mecânico e biológico é apresentado então como uma solução para o cumprimento dos objetivos no tratamento de resíduos em curto prazo. Este trabalho tem o objetivo de analisar tal tecnologia e sua aplicação no município do Rio de Janeiro, avaliando suas vantagens, desvantagens e restrições para este processo. / [en] The progress of humanity and the encouragement of increased consumerism have generated the supply and mass consumption products. A greater extent, so does the production of waste in the world, together with the scarcity of non-renewable resources in the long term, climate change, have diverted attention to environmentally sustainable practices involving waste management. In this context, the Management of Municipal Solid Waste (MSW), translates into a complex process that requires multidisciplinary views, working from the logistics in the process of collection, storage and disposal of waste to the Biology, Chemistry and Thermodynamics, given the diversity of techniques and technologies available for your treatment and recovery in the market. Social development is also an important point, since in countries like Brazil recycling is an activity that generates resources for social classes with lower purchasing power. In addition to operating in the production of consumer goods from waste, much of the recyclable materials back to the market due to the work of sorters, people with very low income, who are in this profession a form of survival. These factors are relevant to the implementation of any management system, which requires significant investment and participation of the public authorities, both legislative and executive. Developed countries, such as members of the European Union (EU), are far ahead in MSW Management, seeking ways of dealing with their waste less and less impactful to the environment. Brazil still is a more technical phase and less practical than the EU, but has important advances. In 2010, entered into force on National Solid Waste Policy (NSWP), established by Law 12.305. This Policy establishes strategies and deadlines for the Brazilian sustainable development, reviews the hierarchy of priorities in waste treatment and imposes the reverse logistics system, and treat life-cycle of products and encourage the reuse, recycling of materials and composting waste, eliminating the dumps and leaving foster landfilling, lagging only this waste without a more favorable allocation to the environment and saving resources.

In biosensors, printing involves the transfer of materials, proteins or cells to a substrate. It offers many capabilities thatcan be utilized in many applications, including rapid deposition and patterning of proteins or other biomolecules.However, issues such as stability when using biomaterials are very common. Using proteins, enzymes, as biomaterialink require immobilizations and modifications due to changing in the structural conformation of the enzymes, whichleads to changes in the properties of the enzyme such as enzymatic activity, during the printing procedures andrequirements such as solvent solutions. In this project, an innovative approach for the fabrication of proteinmicroparticles based on cross-linking interchange reaction is presented to increase the stability in different solvents.The idea is to decrease the contact area between the enzymes and the surrounding environment and also preventconformation changes by using protein microparticles as an immobilization technique for the enzymes. The theory isbased on using a cross-linking reagent trigging the formation of intermolecular bonds between adjacent proteinmolecules leading to assembly of protein molecules within a CaCO3 template into a microparticle structure. TheCaCO3 template is removed by changing the solution pH to 5.0, leaving behind pure highly homogenous proteinmicroparticles with a size of 2.4 ± 0.2 μm, according to SEM images, regardless of the incubation solvents. Theenzyme model used is Horse Radish Peroxidase (HRP) with Bovine Serum Albumin (BSA) and Glutaraldehyde (GL)as a cross-linking reagent. Furthermore, a comparison between the enzymatic activity of the free HRP and the BSAHRPprotein microparticles in buffer and different solvents are obtained using Michaelis-Menten Kinetics bymeasuring the absorption of the blue product produced by the enzyme-substrate interaction using a multichannelspectrophotometer with a wavelength of 355 nm. 3,3’,5,5’-tetramethylbenzidine (TMB) was used as substrate. As aresult, the free HRP show an enzymatic activity variation up to ± 50 % after the incubation in the different solventswhile the protein microparticles show much less variation which indicate a stability improvement. Moreover, printingthe microparticles require high microparticle concentration due to contact area decreasing. However, usingmicroparticles as a bioink material prevent leakage/diffusion problem that occurs when using free protein instead.