This research investigated the mechanism, kinetics and feasibility of nitrate, arsenate, and trichloroethylene inactivation on zerovalent iron (ZVI), mixed-valent iron oxides, and boron doped diamond film electrode surfaces, respectively. Nitrate ( ) is a common co-contaminant at sites remediated using permeable reactive barriers (PRBs). Therefore, understanding nitrate reactions with ZVI is important for understanding the performance of PRBs. This study investigated the reaction mechanisms of with ZVI under conditions relevant to groundwater treatment. Tafel analysis and electrochemical impedance spectroscopy were used to probe the surface reactions. Batch experiments were used to study the reaction rate of with freely corroding and cathodically protected iron wires. The removal kinetics for the air formed oxide (AFO) were 2.5 times slower than that of water formed oxide (WFO).This research also investigated the use of slowly corroding magnetite (Fe3O4) and wustite (FeO) as reactive adsorbent media for removing As(V) from potable water. Observed corrosion rates for mixed valent iron oxides were found to be 15 times slower than that of zerovalent iron under similar conditions. Electrochemical and batch and column experiments were performed to study the corrosion behavior and gain a deeper understanding on the effects of water chemistry and operating parameters, such as, empty bed contact times, influent arsenic concentrations, dissolved oxygen levels and solution pH values and other competing ions. Reaction products were analyzed by X-Ray diffraction and XPS to determine the fate of the arsenic.This research also investigated use of boron doped diamond film electrodes for reductive dechlorination of trichloroethylene (TCE). TCE reduction resulted in nearly stoichiometric production of acetate. Rates of TCE reduction were found to be independent of the electrode potential at potentials below -1 V with respect to the standard hydrogen electrode (SHE). However, at smaller overpotentials, rates of TCE reduction were dependent on the electrode potential. Short lived species analysis and density functional simulations indicate that TCE reduction may occur by formation of a surface complex between TCE and carbonyl groups present on the surface.

Detoxification of chlorinated organic compound is an important and urgent issue in water remediation nowadays. Trichloroethylene (TCE), as a model compound in this study, has been proved to be degraded effectively by bimetallic nanoparticles (NPs) in solution phase. In this study, Fe/Pd bimetallic NPs were synthesized in poly (acrylic acid) (PAA) functionalized polyvinylidene fluoride (PVDF) microfiltration membranes. TCE dechlorination with these bimetallic NPs was conducted under different pH values and different metal loadings to study the role of corrosion on reaction rates. One-dimensional mathematical model with pseudo first-order reaction kinetic was introduced to discuss the TCE dechlorination profile in membrane system. Reduction reaction in pores is affected by several parameters including NP loading and size, TCE diffusivity, void volume fraction and surface-area-based reaction rates. This model result indicated that modification is needed to correct the reaction rate obtained from bulk solution in order to represent the actual efficiency of NPs on reduction reaction. In addition, TCE dechlorination mainly occurred near NPs’ surface. Second part of model indicated that reduction mechanism with TCE adsorption-desorption behavior could be used to discuss dechlorination with a high TCE concentration.

Isotopic methods have been developed over the last 10 years as a method for determining chemical interactions of chlorinated solvents. These methods are especially promising for. This study attempts to employ and develop compound specific isotopic analyses of TCE and cDCE, along with chemical data, to characterize the degradation of TCE in a fractured bedrock aquifers. The Smithville site is a contaminated field site with extremely high levels of TCE contamination that is currently undergoing monitored remediation. From December 2008 until April 2010 extended samples were collected from the site to provide additional data analyses including isotopic data. The redox conditions at the site are anoxic to reducing, with sulfate reduction and methanogenesis as dominant terminal electron accepting processes. Redox data indicates that well electrochemical conditions are highly variable within the site, including areas near the source zone that not very reducing. Documented changes in groundwater conditions to much more reducing environments indicate that oxidation of organic matter is occurring at the Smithville site in select wells. Chemical analyses of TCE, DCE, VC, ethene and ethane are employed determine whether reductive dechlorination was occurring at the site. Results of field testing indicate that many wells on site, especially in the proximity of the source zone, dechlorination products were found. The isotopic data had a high range in both carbon and chlorine isotopes. Chlorine isotopic data ranges from a δ37Cl(TCE) of 1.39 to 4.69, a δ37Cl(cDCE) of 3.57 to 13.86, a δ13C(TCE) of -28.9 to -20.7, and a δ13C(cDCE) of -26.5 to -11.82. The range in values indicate varying degrees of degradation throughout the site, with the same wells grouping together. Combined chemical, redox and isotopic data shows that degradation seems to be a removal process for TCE at the Smithville site. Concentrations of chemicals created as a result of TCE degradation verify degradation, especially in wells 15S9, R7 and 17S9. Historically production of DCE in significant amounts, above 1.0 ppb, was observed to only occur after 2003. In addition to this, DCE data shows that the percentage of DCE made up of cDCE is above 96%. This indicates that microbes most likely mediate the processes that formed DCE from TCE. The linear regression of the delta-delta plot for isotopic TCE data shows line that is likely a direct function of the carbon and chlorine isotopic fractionation imparted upon the original TCE released. The slope found is consistent with data collected from other studies though cannot be applied to determining the process directly given the range of variability in isotopic field data.

Tetrachloroethene (PCE) is a major groundwater contaminant that often persists as dense, nonaqueous phase liquids (DNAPLs) in subsurface environments. Dissolved-phase PCE plumes emanate from DNAPL source zones, which act as continuous sources of contamination for decades. Removal of DNAPL source zones is crucial to achieve lasting remedy of contaminated aquifers. This research explored the contributions of the microbial reductive dechlorination process (i.e., anaerobic bioremediation) to PCE-DNAPL source zone remediation, either in isolation or as a polishing step for the removal of residual DNAPL remaining after application of surfactant enhanced aquifer remediation (SEAR), an emerging physical-chemical source zone treatment. Specific objectives of this research were to: (1) evaluate the ability of microorganisms to dechlorinate in the presence of PCE-DNAPL and at high dissolved-phase PCE concentrations expected near/in DNAPL source zones, (2) assess the distribution and activity of key dechlorinating populations during bioenhanced PCE-DNAPL dissolution in continuous-flow column experiments, (3) determine the influence of Tween 80, a biodegradable surfactant commonly used in SEAR, on the microbial reductive dechlorination process, (4) design and optimize quantitative real-time PCR (qPCR) protocols to detect and enumerate key dechlorinating populations (e.g., Geobacter lovleyi, Sulfurospirillum multivorans), and (5) explore the effects of oxygen on Dehalococcoides viability and biomarker quantification. This research demonstrated that microbial dechlorinating activity within DNAPL source zones promotes bioenhanced dissolution although many dechlorinating isolates cannot tolerate saturated PCE concentrations. Application of newly designed qPCR protocols established a direct link between dissolution enhancement and the distribution of relevant dechlorinating populations in the vicinity of PCE-DNAPL. The limited and reversible impact of Tween 80 on key dechlorinators supported the feasibility of a treatment train approach of SEAR followed by microbial reductive dechlorination to remediate PCE-DNAPL source zones. Finally, experiments with oxygen-exposed, Dehalococcoides-containing cultures suggested limitations of using Dehalococcoides DNA and RNA biomarkers for monitoring bioremediation at field sites. These findings advance the scientific understanding of the microbial reductive dechlorination process and are relevant to environmental remediation practitioners. The advantages and current shortcomings of PCE-DNAPL source zone bioremediation, as well as recommendations for future research, are discussed.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / O exercício físico é capaz de gerar adaptações fisiológicas agudas e crônicas ao tecido, e apesar de inicialmente aumentar a formação de espécies reativas de oxigênio (EROs), é capaz de ativar a síntese de enzimas antioxidantes atenuando o estresse oxidativo. Seus efeitos vêm sendo estudado como opção terapêutica na prevenção e tratamento de isquemia cerebral, epilepsia, doença de Parkinson e traumatismo cranioencefálico (TCE) experimentais. O TCE além da lesão local primária pode interferir na função de múltiplos órgãos e sistemas metabolicamente ativos como o fígado causando disfunção hepática e exacerbando a lesão cerebral inicial. Neste contexto, conhecendo os inúmeros benefícios do exercício, especialmente sobre a função hepática frente diferentes patologias, o presente trabalho teve como objetivo avaliar o efeito do treinamento físico prévio sobre os marcadores de estresse oxidativo no fígado de ratos submetidos ao TCE. Para tal, o presente estudo utilizou ratos Wistar adultos machos submetidos ao TCE ou não, sendo divididos em quatro grupos separados aleatoriamente para realização do protocolo de natação cinco dias por semana durante seis semanas. Foi evidenciado que o exercício prévio de natação alterou o estado redox das células hepáticas, sendo capaz de proteger contra a diminuição nos níveis de GSH e aumento na oxidação do DCHF produzido pelo TCE 24 horas após a injuria neuronal. A análise estatística também revelou que o TCE induziu uma diminuição no potencial de membrana mitocondrial (ΔΨ) e atividade das desidrogenases nas mitocôndrias (MTT) nos animais sedentários, sendo que esta diminuição não ocorreu nos animais treinados. O presente modelo experimental de TCE diminuiu a atividade da enzima succinato desidrogenase (SDH) em animais treinados quando comparado aos controles sedentários, aumentou o conteúdo de proteína carbonil e diminuiu a atividade da enzima Na+, K+-ATPase nos animais sedentários, o que foi atenuado pelo protocolo prévio de treinamento físico de natação. Já as análises bioquímicas das atividades das enzimas antioxidantes revelaram que o protocolo de natação atenuou o aumento da atividade da enzima SOD e protegeu da inibição da enzima catalase induzidas pelo TCE. A análise estatística revelou que o exercício físico bem como o TCE não alterou a expressão de Hsp70, Nrf2, níveis sérico de Aspartato-aminotransferase (AST), Alanina-amintransferase (ALT) e lesão hepática quando analisado 24 horas após a injuria neuronal. A partir destes achados sugere-se que o nosso protocolo de natação apresenta efeitos protetores sobre a função mitocondrial e consequentemente na produção de EROS induzidas pelo TCE e, apesar das alterações oxidativas geradas pelo TCE no fígado não afetarem a viabilidade celular hepática, nossos dados experimentais traduz um novo fenótipo hepático que é mais suscetível às consequências deletérias associadas ao TCE.

Submitted by Rafaela Moraes (rafaela.moraes@fgv.br) on 2016-09-08T12:49:07Z No. of bitstreams: 1 Dissertacao_CarlosMenezes.pdf: 2839521 bytes, checksum: fa6e03cda8060d170b8c16f0e84bd9fd (MD5) / Approved for entry into archive by Rafaela Moraes (rafaela.moraes@fgv.br) on 2016-09-08T12:52:28Z (GMT) No. of bitstreams: 1 Dissertacao_CarlosMenezes.pdf: 2839521 bytes, checksum: fa6e03cda8060d170b8c16f0e84bd9fd (MD5) / Approved for entry into archive by Rafaela Moraes (rafaela.moraes@fgv.br) on 2016-09-08T13:08:19Z (GMT) No. of bitstreams: 1 Dissertacao_CarlosMenezes.pdf: 2839521 bytes, checksum: fa6e03cda8060d170b8c16f0e84bd9fd (MD5) / Made available in DSpace on 2016-09-08T13:08:58Z (GMT). No. of bitstreams: 1 Dissertacao_CarlosMenezes.pdf: 2839521 bytes, checksum: fa6e03cda8060d170b8c16f0e84bd9fd (MD5) Previous issue date: 2008 / O objetivo deste estudo é levantar a influência da criação da Escola de Consta e Gestão do Tribunal de Contas do Estado do Rio de Janeiro na mudança da percepção da imagem da marca coorporativa do Tribunal de Contas do Estado do Rio de Janeiro segundo a percepção dos servidores. O estudo foi feito sob o enfoque da fenomenologia, sendo dado tratamento de categorias filosóficas para a percepção e para a imagem. O conceito de marca foi analisado sob o enfoque do marketing. A pesquisa de campo foi feita por meio de entrevistas semi-estruturadas e desenhos elaborados pelos respondentes. Chegou-se à conclusão que a criação da ECG influenciou a percepção de mudança na imagem do TCE, embora tal influência não tenha sido notada na percepção da missão institucional da organização.

In situ chemical oxidation (ISCO) using permanganate has been increasingly applied to deplete mass from dense nonaqueous-phase liquid (DNAPL) source zones. However, uncertainty in the performance of ISCO on DNAPL contaminants is partially attributable to a limited understanding of interactions between the oxidant, subsurface hydrology, and DNAPL mass transfer, resulting in failure to optimize ISCO applications. To investigate these interactions, a factorial design experiment was conducted using one-dimensional flow through tube reactors to determine how groundwater velocity, permanganate concentration, and DNAPL type affected DNAPL mass depletion rates. DNAPL mass depletion rates were found to increase with increasing groundwater velocity, or increasing oxidant concentration. An interaction occurred between the two factors, where high oxidant concentrations had little impact on mass depletion rates at high velocities. High oxidant concentration systems experienced gas generation. Mass depletion rates were fastest at high velocities, but required additional oxidant mass and pore volume addition to achieve complete mass depletion. Lower-velocity systems were more efficient with respect to oxidant mass and pore volume requirements, but mass depletion rates were reduced.

The Operable Unit 5 (OU 5) area of Hill Air Force Base currently has two trichloroethene-contaminated groundwater plumes underneath residential areas in Sunset and Clinton, Utah. Bioremediation by biological reductive dechlorination can be an important mechanism for the removal of chlorinated compounds from the plumes. The presence of suitable bacteria to carry on reductive dechlorination is the key in the bioremediation process. The goal of this study was to determine the distribution and population density of the 16S rRNA genes of Bacteria, Dehalococcoides ethenogenes, Desulfuromonas michiganensis, Geobacter spp and Rhodoferax ferrireducens-like bacteria, as well as the functional genes trichloroethene reductive dehalogenase (tceA) and vinyl chloride reductase gene (vcrA). This study also evaluated the influence of the physical-chemical properties of the OU 5 aquifer material on the observed bacterial distribution. Twenty OU 5 soil cores were obtained from a 14-ha area that included a trichloroethene (TCE) plume. DNA was extracted from each core. Molecular analysis with qRT-PCR was used to quantify the densities of the mentioned 16S rRNA and functional genes. Separately, total arsenic and iron in the II and II+III oxidation states were extracted by two methods (HCl and hydroxylamine HCl in HCl) in each core. Concentrations of TCE, cis-dichloroethene (cis-DCE), vinyl chloride (VC) and ethane in well water were included. Dehalococcoides population density was low and its distribution was uneven with densities lower than 3.2x104 copies/g (detection limit of 2.5x103). D. michiganensis distribution was not uniform but was clustered near the TCE-source area with densities of 7.9x103-1x105 copies/g (detection limit of 6.3x103). Geobacter spp. distribution was uneven but broader, with densities of 4x103-1.6x106 copies/g (detection limit of 3.2x103). The vcrA gene distribution was relatively uniform and broad. Densities were the lowest measured (detection limit of 63 copies/g). TceA was measured in two cores with densities close to detection limit of 1.6x103 copies/g. Rhodoferax ferrireducens-like bacteria had a broader distribution with the highest densities of 1.6x106-1.3x108 copies/g (detection limit of 7.9x103). Total Bacteria were measured in all cores with densities 3.2x104-3.2x106 copies/g (detection limit of 1x103). Three multivariate statistical methods were used to determine the effect of physical-chemical properties on the target gene distributions. Cluster and discriminant analysis selected five properties (pH, sand and silt content, NO3--N and NH4+-N) as the most discriminating factors among thirty-one physical-chemical properties. However, no effect in the bacterial distribution was observed. The tree classification method identified nine variables that described higher or lower densities of the target genes. Variables such as Bacteria, Fe(II+III) (by hydroxylamine HCl in HCl), organic matter and cis-DCE were selected by the method.. All methods agreed on the selection of pH and sand content as the physical/chemical factors most influencing in the bacterial distribution. Based on the findings of low densities of dechlorinating bacteria and dechlorinating-associated functional genes, low available carbon donor and sandy mineral composition, the partial TCE-dechlorination at this site can be ascribed to the nature of the site and incomplete set of required factors for complete reductive dechlorination.

No description available.

Examensarbete, Civilekonomprogrammet, Ekonomihögskolan vid Linnéuniversitetet, Företagsekonomi, 4FE17E, VT-2018. Författare: Jeanette Elbe och Ludvig Eriksson Handledare: Andreas Jansson Examinator: Karin Jonnergård Titel: Ekonomifunktionens roll för beslutsfattarna - Intern eller extern funktion i förhållande till organisationen? Sökord: Outsourcing, Ekonomisk administration, Kostnadslogiken, Strategiska logiken, Transaction Cost Economics, TCE, Resource-based View, RBV, Ekonomifunktionens roll   Bakgrund: Att betala en extern part för att utföra bolagets ekonomiska administration är ett växande fenomen och outsourcing av ekonomiska företagsprocesser är högaktuellt att förstå sig på. I outsourcinglitteraturen finns det två perspektiv som kan lyftas upp för att förklara outsourcingbeslutet och genom att studera beslutsfattarnas logik till outsourcingbeslutet tror sig författarna kunna bidra till en djupare förståelse inom ämnet.   Syfte: Studien syftar till att öka förståelsen för de logiker som ligger till grund för beslutsfattares outsourcingbeslut av den ekonomiska administrationen.   Metod och genomförande: Genom användandet av idealtyper bygger författarna upp två differentierade logiker för att utreda olika beslutsfattares förhållningssätt till outsourcing av ekonomisk administration - kostnadslogiken och den strategiska logiken. Logikerna har sedan studeras empiriskt genom en intervjustudie kopplad till ledande befattningshavare i medelstora företag lokaliserade i den småländska GGVV-regionen.   Slutsats: Studien visar att beslutsfattare som outsourcar större delar av den ekonomiska administrationen förhåller sig till kostnadslogiken. Den strategiska logiken är istället nära sammankopplad med den rationalitet som föreligger hos beslutsfattare som väljer att inte outsourca sin ekonomiska administration. Däremellan sker även ett möte mellan logikerna. De beslutsfattare som outsourcar mindre delar av den ekonomiska administrationen tar taktiska beslut vilket visar på ett yttrande gentemot kostnadslogiken. Dock blir det tydligt att det samtidigt finns ett bakomliggande strategiskt tankemönster i hur dessa beslutsfattarna resonerar kring ekonomifunktionen. Beslutsfattarna som omfattas av den strategiska logiken hämmas därför i dessa fall att outsourca större delar av ekonomifunktionens arbete. / Master Thesis in Business Administration, School of Business and Economics, Linnaeus University, 4FE17E, 2018. Author: Jeanette Elbe and Ludvig Eriksson Supervisor: Andreas Jansson Examiner: Karin Jonnergård   Title: The role of the accounting function for decision makers - An inhouse or outhouse function in relation to the organization? Keywords: Outsourcing, Accounting, Logic of cost, Strategic logic, Transaction Cost Economics, TCE, Resource-based View, RBV, The role of the accounting function   Background: Paying an external party to perform the company’s financial administration is a growing phenomenon and outsourcing of accounting and financial processes are highly relevant to understand. In the outsourcing literature, there are two perspectives that can be raised to explain the outsourcing decision, and by studying the decision makers’ logic to the outsourcing decision, the authors believe that they can contribute to a deeper understanding of the subject.   Purpose: The aim of this study is to increase the understanding of the logic that underlies decision makers' outsourcing decisions of the financial administration.   Method: Using ideal types, the authors build up two differentiated logics to investigate different decision makers' approaches to outsourcing of financial administration - the logic of cost and the strategic logic. The logics have been studied empirically through an interview study linked to senior executives in medium-sized companies located in the GGVV-area in the province of Småland in Sweden.   Conclusion: The study shows that decision makers who outsource major parts of the economic administration relate to the logic of cost. However, the strategic logic is closely linked to the rationality of decision makers who choose not to outsource their financial administration. In between, there is also a meeting between the logics. The decision makers who outsource smaller parts of the economic administration carry out tactical decisions, which indicates a relationship to the logic of cost. Anyhow, it becomes clear that there is an underlying strategic thinking pattern in how these decision makers argue about the financial function as a hole. The decision makers covered by the strategic logic are therefore in these cases hampered to outsource major parts of the financial administration.