Orientador: Raquel Fernandes Pupo Nogueira / Banca: Renato Sanches Freire / Banca: Antonio Carlos Silva Costa Teixeira / Banca: José Ermínio Ferreira de Moraes / Banca: Valquíria de Campos / Resumo: Avaliou-se neste trabalho a degradação oxidativa do contaminante modelo 2,4-D, um herbicida, pelo sistema Fe0/ O2. Para isto foram estudados diversos parâmetros como: concentração de Fe0, variação de pH, concentração de 2,4-D, presença de ligantes, variação de pH na presença de ligantes, efeito da concentração dos ligantes EDTA e DTPA, variação da velocidade de agitação e borbulhamento de ar, efeito do tamanho de partícula de Fe0 e da presença de ânions comumente encontrados em efluentes ou águas subterrâneas contaminadas. Os resultados obtidos mostram que a degradação de 2,4-D, na ausência de ligantes, alcança ca. de 50% para concentrações de 1 ou 2% (m/V) de Fe0 em 60 ou 150 minutos, respectivamente, sendo a velocidade de degradação inversa ao aumento da concentração de Fe0 para reações com ajuste de pH inicial em 3. Nas reações com pH ajustado ao longo de todo o período observou-se um aumneto da velocidade de reação com a diminuição do pH. A presença de EDTA e DTPA aumentou a velocidade de degradação de 2,4-D em todos os valores de pH estudados e expandiu a faixa de aplicação do sistema para pHs neutros. O aumento da concentração de EDTA resulta no aumento da velocidade de degradação de 2,4-D. A degradação de EDTA também foi observada durante a reação. A diminuição da velocidade de agitação, assim como a retirada do borbulhamento de ar do sistema, diminuem a velocidade de degradação de 2,4-D. O Fe0 microparticulado apresentou uma cinética de degradação bimodal e bem mais lenta em relação ao nanoparticulado. A presença de cloreto, sulfato, bicarbonato ou hidrogenofosfato não alterou a velocidade de degradação de 2,4-D no sistema com DTPA, entretanto o nitrato exibiu uma leve inibição do processo. Foram avaliados também a reatividade e o tempo de vida de diferentes... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The oxidative degradation of the herbicide 2,4-D promoted by Fe0/O2 system has been evaluated. Several parameters have been studied like: Fe0 and 2,4-D concentrations, pH, effect of different ligands, EDTA and DTPA concentrations, speed rate and air bubbling, Fe0 particle size and presence of anions usually found in wastewater or contaminated groundwater. The results show that, in absence of ligands, 2,4-D degradation reaches up to 50% in 150 minutes for 2% Fe0 and that the degradation rate decreased as the Fe0 concentration increased. In stabilized pH reactions the degradation rate increased as the pH decreased. The presence of EDTA or DTPA enhanced 2,4-D degradation for all pH values evaluated and enlarged the reactive zone to neutral pH. Increasing EDTA concentration resulted in an increase of 2,4-D degradation rate. EDTA degradation is also observed during the reaction. Decreasing speed rate, as well as turning the air bubbling off, resulted in lower 2,4-D degradation. The use of microparticulated Fe0 turned the 2,4-D degradation kinetics in a bimodal process besides slowing it down. Sulfate, chloride, bicarbonate and phosphate didn't change 2,4-D degradation rate, however nitrate slightly inhibited the process in presence of DTPA. The reactivity and lifetime of some commercial Fe0 nanoparticles (Nanofer 25, Nanofer 25S and Zloy) were also evaluated for TCE reduction. The TCE reduction by different materials showed that kobs has decreased in synthetic groundwater in comparison to deionized water. The stabilizing polymer shell on the surface of Nanofer 25S protected the metallic iron from water corrosion and prevented the inhibition action of anions on TCE reduction. Zloy showed the highest reduction rate for TCE and for water as well, having a very short lifetime (5 days) in deionized water. However the... (Complete abstract click electronic access below) / Doutor

Forensic crime laboratories receive hair shafts as evidentiary samples and process them for DNA evidence as a means of identification of individuals. The Armed Forces DNA Identification Laboratory (AFDIL) provides DNA analysis to aid in the medico-legal death investigation of fallen service members and contributes to research and education in the field of forensic DNA analysis. The AFDIL receives hair samples from family members of service individuals as a reference standard as well as remains from both past and present day conflicts for identification. Often times nuclear DNA is too highly degraded in hair shafts to be obtained successfully. There are many more copies of mitochondrial DNA in a cell than nuclear DNA. Therefore, it is common practice to target mitochondrial DNA instead of nuclear DNA when processing a hair shaft for DNA evidence. Mitochondrial DNA also plays an important role at the AFDIL in familial identification when a self-reference standard is not available. The current validated protocol for extracting mitochondrial DNA (mtDNA) at the AFDIL is a manual digestion with a micro-tissue grinder followed by a 24-hour incubation step and an organic phenol-chloroform extraction. The first part of this study compares the currently validated organic extraction method with the new QIAGEN QIAamp® Fast DNA Tissue Kit extraction method. The QIAamp® Fast DNA Tissue Kit extraction is a mechanical, chemical, and enzymatic protocol involving a 2 mL disruption tube with a stainless steel bead which aides in disruption of the hair followed by a silica-column based purification. The QIAamp® Fast DNA Tissue Kit is a single day protocol which reduced lab processing time by more than half (7 hours to 3 hours). When results from six different hair samples extracted with the current organic method were compared with the same samples extracted with the QIAamp® Fast DNA Tissue Kit method, it was found that the two methods are comparable for mtDNA recovery, amplification, and sequencing. Recently, researchers at InnoGenomics© (New Orleans, LA) have developed nuclear DNA quantification and amplification kits that target small DNA fragments, creating the potential to obtain sufficient nuclear DNA data from samples containing highly degraded DNA. Instead of targeting loci that contain short tandem repeats (STRs), the InnoQuant™ DNA quantification kit and InnoTyper 21™ DNA typing kit (InnoGenomics©, New Orleans, LA) targets retrotransposable elements (REs). The second part of this study compares nuclear DNA extraction methods from hair shafts such as the QIAamp® Fast DNA Tissue Kit, a direct lysis procedure using ZyGEM® prepGEM™ enzyme, and direct lysis procedures using pronase. Nuclear DNA extracts were quantified InnoQuant™ and InnoTyper 21™ for DNA typing. Full profiles were obtained using the InnoTyper 21™ amplification kit from samples with as low as 0.0331 ng of DNA which were extracted with 0.05 mg/mL. However, no single extraction method demonstrated consistently higher DNA concentrations or more complete DNA profiles.

Filmes de polietileno (PE) contendo aditivo pró-degradante à base de um composto de cobalto foram expostos a intemperismo natural por 12 meses, em Canoas, RS (30º S, 59º W), sob condições de umidade ambiente e saturação de umidade. Procurou-se desenvolver condições de ensaio adequado para a degradação abiótica e biótica, visando monitorar alterações na estrutura da cadeia e propriedades mecânicas. Obtiveram-se valores crescentes de índice de carbonila com o aumento do tempo de exposição ao intemperismo natural, por meio de espectroscopia de infravermelho por transformada de Fourier (FTIR). A massa molar ponderal média decresceu de 170.000 para próximo de 8.000 g mol-1 com 4 – 5 meses de exposição, com fragilização progressiva das amostras e diminuição da resistência mecânica. A degradação biótica dos resíduos de PE originados a partir da degradação abiótica foi realizada em células fechadas, a 58º C. Após 90 dias de ensaio, as amostras de PE tiveram 12 % do seu carbono convertido a CO2, contra 70% obtidos com celulose (padrão positivo). Mesmo com essa diferença elevada em relação ao padrão positivo, a biodegradabilidade desenvolvida pelo PE pode ser considerada muito boa, uma vez que a biodegradação dessa poliolefina sem aditivo promotor de degradaçao é extremamente pequena. Assim, o aditivo pródegradante teve uma eficiência significativa em acelerar a degradação abiótica dos filmes de PE expostos ao intemperismo natural, em condições de umidade ambiente ou saturação de umidade. / Plastic bags of polyethylene (PE) containing cobalt prodegradant additive were exposed to natural weathering for 12 months, in Canoas, RS (30° S, 59º W). An appropriate test methodology for monitoring abiotic and biotic degradation was chosen, with evaluation of changes in the structure of the polymeric chain, mechanical parameters and biodegradation. Increasing results of carbonyl index demonstrated accelerated oxidation of the samples. The molar mass (weight average) decreased from 170.000 to 8.000 g mol-1 after 4 – 5 months of exposure, being followed by fragilization and mechanical resistance decrease. Biotic degradation tests of PE bags residues were performed in closed vessels, at the temperature of 58 ºC. According to the tests, residues of PE films reached a mineralization of 12% after 90 days, compared to 70 % for cellulose. That degree of biodegradation may be considered high, because biodegradation of PE films not containing prodegradant additives is very slow. Thus, the additive was showed efficient to accelerate the abiotic degradation, conferring biodegradability to PE films.

Diese Dissertationsarbeit liefert einen Beitrag zur Erfassung und Bewertung von Degradationsprozessen im semi-humiden Süden Spaniens. Der erste Teil der Arbeit widmet sich der detaillierten physisch-geographischen Charakterisierung des Großraumes, um danach in dem kleinräumigen Einzugsgebiet des Arroyo del Alforzo, einem Tributär des Río Turón, zwei unterschiedliche Ansätze zur Erfassung von die degradationsbeeinflussenden Fatoren wie Landnutzungswechsel und Starkniederschlagsereignissen in diesem Raum zu untersuchen. Anhand von drei Satellitenbildern wurde der Landnutzungswechsel ermittelt und im Untersuchungsgebiet die Abhängigkeit zu den Hangneigungen untersucht. Vor dem Hintergrund, daß unterschiedlich starke Hangneigungen einen unterschiedlich starken Einfluss auf die Abtragsdynamik bei Niederschlägen hat, wurden anhand der Landnutzungsklassifizierungen in Kombination mit den Hangneigungnen sensible Räume ermittelt. Ein weiterer Ansatz ist die Untersuchung von Tagesniederschlagsdaten auf Starkniederschlagsereignisse, mit dem Ziel, diese zu separieren. Es galt die Annahme, daß diese Starkniederschlagsereignisse im Einzugsgebiet des Arroyo del Alforzo oberflächlichen Abfluss generieren und somit ein bedeutender Sedimenteintrag aus den sensiblen Bereichen des Untersuchungsgebiet in den Stausee Conde de Guadalhorce stattfindet. Mittels sedimentstratigraphischer Untersuchungen an den Sedimenten des 2006 gewonnenen Bohrkerns aus dem Mündungsbereich des Arroyo del Alforzo in den Stausee Conde de Guadalhorce sollte dieser Sedimenteintrag identifierziert werden und somit ein zeitlicher und räumlicher Rückschluss auf die die Abtragung beeinflussenden faktoren Landnutzungswechsel, Hangneigung und Niederschlag efolgen. Die Annahme, dass sich diese Rückschlüsse ziehen lassen können auf der Grundlage des Bindeglieds „Sedimentbohrung“ erwies sich jedoch als zu eng. In einer abschliessenden Bewertung wurde erläutert, daß durch eine gezielte methodische Ergänzung jedoch die Möglichkeit besteht, die Unsicherheiten, die durch eine räumlich wie zeitlich inkonsistente Datenlage der Niederschlagsdaten und die in einem Stausee herrschende spezielle Akkumulationsdynamik hervorgerufen wurde, beseitigt werden kann. / not available

In the decade before 2005, South African organisations have had to cope with an ever-increasing rate of local and global changes. There have been considerable and ongoing socio-political changes, resulting from new Government regulations. Most organisations have experienced some type of downturn, whether due to external business factors or poor internal performance. A typical response to organisational decline is retrenchment. Retrenchment is attributed to cyclical downturns, market losses or other economic factors, which oblige the employer to reduce the labour force numbers. Though there are so many ways of responding to organisational failure, this study focused only on retrenchment. A number of psychologists and human sciences researchers have studied the results of job loss due to retrenchment. Retrenchment brings loss of skills, loss of morale and commitment, as well as physical and mental health degradation, including stress that results in employees withdrawing physically and emotionally. The main purpose of this study was to outline the employees’ perceptions of the effects of retrenchment on job stress and organisational commitment in a mining company. The research methodology used in this study is a combination of a literature review and an empirical study. The probability sampling technique, which entails using simple random sampling, was used to select the sample of the study. The primary data were collected using a questionnaire. The measuring instrument contained 43 items. The measuring instrument was pilot-tested with 50 respondents three weeks before the main survey; the questionnaire was self-administered to the participants. For the main survey, data from 294 respondents were collected and analysed. Participants in the study involved surface employees, including management, administrators, engineers and artisans. Data were analysed with the Statistical Package for Social Sciences (SPSS) version 23.0. The Cronbach’s alpha coefficients of the various sections of the measuring instrument were computed to establish construct validity. Content validity was ascertained by pre-testing the questionnaire with the employees in the mine in question. Correlations were used to establish convergent validity of the constructs. Convergent validity was assessed to measure the degree of linear association of variables using Pearson’s correlation coefficient. Discriminant validity was achieved by using regression analysis to show items loaded onto different factors in various sections which had more than one factor. Analysis was done using descriptive statistics on the demographic information of respondents. The results were also interpreted through correlation and regression analysis. The results showed that the effects of retrenchment did not have a negative impact on job stress (time stress and anxiety). This may be due to the mine in question planning and consulting with the employees prior to the retrenchment process. The results also showed that job stress (time stress and anxiety) is negatively associated with organisational commitment. Subsequent to these findings, it is recommended that employees (survivors) be updated on their future in the company in question. This could be done through regular workshops and counselling of employees. In order to motivate and engage employees, and thereby contribute to employee commitment, it was also recommended that organisations create open, supportive and fair organisational and team cultures, and ensure jobs are clearly aligned with organisational goals and have appropriate levels of autonomy, support and career development. Given that job satisfaction plays a huge role in organisational commitment, it was further recommended that managers need to actively improve their organisation’s job satisfaction to employees in order to achieve a higher level of organisational commitment. The study concludes by recommending that communication between employees and management should take place on a regular basis which can serve as a fundamental tool to retrenchment in the following manner: • Survivors will feel more committed to the organisation when the basis of retrenchment addresses the circumstances in the external environment, rather than the enrichment of shareholders or top management. • Communicating a clear vision of how retrenchment will benefit stakeholders, increases commitment since survivors can see a clear future for the organisation. • When survivors are treated with dignity and respect, they will feel more committed to the organisation because they feel appreciated.

Despite microbial degradation being the primary route of degradation of PAHs in soils, high molecular weight polycyclic aromatic hydrocarbons (such as benzo[a]pyrene) have consistently proven to e resistant to microbial attack. However, recent research has demonstrated the potential for bacterial-fungal co-cultures to achieve biodegradation of high molecular weight PAHs. The aim of this research was to determine the efficacy of co-culture bioaugmentation for the remediation of high molecular weight PAHcontaminated soils. PAH degrading bacteria were enriched on multiple PAHs and isolated on pyrene from both contaminated (soil from a former manufactured gas plant) and uncontaminated (agricultural soil, termite mound matrix and kangaroo faeces) sources. The bacterial isolates were identified using 16SrRNA analysis as Mycobacterium sp. Strain BS5, Mycobacterium sp. Strain KA5 and Mycobacterium sp. Strain KF4 or fatty acid methyl ester (FAME) analysis as Ralstonia pickettii and Stenotrophomonas maltophilia. The initial phase of assessment of PAH degradation by fungal and bacterial coculture components was undertaken using liquid media. Two fungal isolates from a previous investigation into the coculture process (Penicillium janthinellum) and the American Type Culture Collection (Phanerochaete chrysosporium) were assessed for their ability to degrade benzo[a]pyrene in minimal media and MYPD. The fungal isolates were found to be able to degrade benzo[a]pyrene cometabolically in MYPD. The bacterial isolates and two others from previous investigations were assessed for their ability to degrade single PAHs (fluorene, phenanthrene, fluoranthene, pyrene and benzo[a]pyrene) in liquid culture. This process was used as an initial screen to select the best bacterial isolates for further investigation of PAH degradation by axenic cultures and cocultures with the fungal isolates using a PAH mixture. Based on the results of these experiments four bacterial isolates (VUN 10,010, Mycobacterium 1B, Mycobacterium sp. Strain BS5 and Mycobacterium sp. Strain KA5) and the two fungal isolates were selected to investigate further using a PAH mixture composed of the previously mentioned PAHs. It was found that the use of a fungal bacterial coculture increased the degradation of the PAH mixture beyond that of axenic bacterial cultures. Based on these experiments, the coculture composed of P. janthinellum and VUN 10,010 was selected for assessment of its ability to degrade the same PAH mixture in spiked soil microcosm experiments. Natural attenuation, axenic P. janthinellum, axenic VUN 10,010 and a coculture of these two organisms were assessed for PAH degradation in soil microcosms over a 100 day period. Inoculation of microcosms with the coculture resulted in the removal of benzo[a]pyrene by 11 mg/kg (± 1.21 mg/kg) (30%) over the 100 day incubation period. Substantial PAH degradation was also observed in the microcosms assesing natural attenuation. Using an alternative sequential inoculation method, initially inoculating with P. janthinellum then 50 days later with VUN 10,010 significantly enhanced the removal of benzo[a]pyrene. After 100 days incubation, benzo[a]pyrene was degraded below detection limits in two of three microcosms, compared to a 4.95 mg/kg (± 4.64 mg/kg) (14.7 %) reduction in soil microcosms inoculated using an alternative inoculation process of VUN 10,010 followed by P. janthinellum. Attempts were made to optimise the process using sequential inoculation and soil amendments intended to enhance the performance of the fungal component using distilled water and 1% glucose. The addition of distilled water was not observed to substantially influence the ability of the coculture to degrade PAHs, whereas the addition of 1% glucose was found to inhibit PAH degradation.

The moisture absorption behavior of Zylon fibers was characterized in various high temperature and high humidity conditions in a controlled environment. The results of these thermal cycling tests show that PBO fibers not only absorb, but also retain moisture (approximately 0.5-3%) when exposed to elevated temperature and humidity cycles. Also, the impurities of Zylon fibers were characterized through the use of Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and solid state Nuclear Magnetic Resonance (NMR). These tests demonstrated that, in addition to other impurities, PBO fibers may contain up to 0.55 weight percent phosphorus, and that this phosphorus is present in the form of phosphoric acid. It was also shown through accelerated hydrolytic degradation tests that production procedures used to neutralize the acid present in the fibers have a beneficial effect on the hydrolytic performance of the fiber. The data collected in this study was then compared and contrasted to known Kevlar studies, identifying similarities, differences, and potential trends. The results of these tests seem to indicate that there is accelerated acid catalyzed hydrolysis occurring in the fiber which is causing these fibers to degrade at an increased rate. This condition is further accelerated by heat and humidity induced permanent fiber swelling.

A billion tons per year of genetically modified corn residues are soil incorporated having both direct and indirect effects on the belowground environment, soil carbon (C) sequestration, and nutrient cycling. If Bt genetic modification has non-target effects on corn stover structural/non-structural carbohydrate and nitrogen (N) concentrations, then the degradation rate of Bt-corn stover may be different than that of non-Bt isolines, possibly influencing soil C storage and N mineralization. Thus, this research focused primarily on the comparison of C and N mineralization of corn stover in soil as affected by Bt-trait, plant portion, water-availability and HFC-trait; and secondarily on the existence of Bt-related variations in the chemical structure of corn residues that might affect the degradation rate of stover in soil and consequently the soil C and N dynamics. A laboratory experiment was conducted under non-limiting N conditions with stover of Bt/non-Bt isogenic pairs of two varieties, a ?high fermentable corn? (HFC) line harvested at Snook, Texas and a non-HFC corn line harvested at the irrigated field of Snook and the non-irrigated field of College Station, Texas. The stover was partitioned into three plant portions, incorporated into a Weswood soil and incubated during 223 days. Results showed that the differences observed in the degradation in soil of Bt vs. non-Bt corn stover were dependent on environmental conditions (irrigated vs. non-irrigated settings) and hybrid variety (HFC vs. non-HFC hybrid lines). The structural composition of corn plants was affected by the Bt-trait, HFC-trait, irrigation and their interactions. Variations in the biomass fractions of the initial stover of Bt and non-Bt hybrids had minimum to non-impact on soil C and N concentrations measured at the end of the 223-day incubation period. Lignin concentration was affected by a Bt-trait*variety interaction. There were no significant differences in lignin concentration between non-Bt/Bt-corn derived stovers of the non-HFC variety irrespective of irrigation regime but Bt-hybrids of the HFC variety contained more than twice as much lignin as the non-Bt isogenic plants. The effects of higher lignin concentration on C mineralization rate appeared to be offset by an increased lignin degradability inherent in HFC-trait. Overall, results indicated that the cultivation of Bt-modified maize lines is not likely to have significant effects on soil C or N dynamics compared with the cropping of non-Bt hybrids.

A large amount of Nile water originates in Ethiopia. However, large uncertainty arises concerning whether land degradation or climate change is the cause for the observed increase in discharge along downstream countries. Previous studies showed increases in discharge at Kessie, Bahir Dar and El Diem over the past four decades with no increase in basin-average rainfall. They cite changes in landscapes or soil coverage as a potential reason for this change. However, the study in this thesis shows that the change in discharge could also be explained in part by spatial changes in precipitation. This thesis investigates trends in rainfall within the Blue Nile River Basin f rom 1963 to 2003. For this study total monthly and daily precipitation data were collected from across the Blue Nile River Basin and analyzed statistically. The results indicate spatial variability in the rainfall observed. The general long-term trends in annual as well as in seasonal precipitation show a general decreasing trend along southwest regions of the study area. However, an increasing  trend was encountered along northeast and southeast region of the Basin (3 of 9 selected stations). Rainfall-runoff modelling was performed to estimate the required precipitation increase to produce the increase in discharge observed in the Blue Nile River Basin. Precipitation needed to increase between 10 % and 25 % to account for the increased discharge. This increase is similar to that observed for some of the precipitation stations showing that increase in discharge seen in the Blue Nile River Basin may in part be due to changes in precipitation.

The purpose of this thesis is to explore the concept of environmental security. A concept that have made way on to the international arena since the end of the Cold War, and have become of more importance since the 1990’s. The discussion regarding man-made environmental change and its possible impacts on the world is very topical; especially with the Nobel Peace Prize winners in 2007 the Intergovernmental panel on climate change (IPCC) and Al Gore.The concept of environmental security is examined through a conceptual investigating study. The reason for this type of study is due to the complexity of the concept and a hope to find a ‘best’ definition to it. A conceptual investigating study is said to help create order in an existing discussion of a social problem, hence the reason for it in this thesis. The outcome of this thesis is that it is near impossible to find a ‘best’ or one definition to the concept of environmental security and that another method to deal with the concept might have presented another result. / Syftet med denna uppsats är att undersöka konceptet environmental security. Detta koncept har gjort sin väg till ett internationellt erkännande sedan Kalla kriget, och har sedan 1990-talet blivit allt mer aktuellt. Diskussionen gällande människans inverkan på klimatförändringarna och klimathotet är ständigt aktuellt, i synnerhet med tanke på vinnarna av Nobels Freds Pris 2007, med Al Gore i spetsen.Konceptet environmental security är i denna uppsats undersökt genom en begreppsutredande studie. Anledningen till denna typ av studie är att konceptet är såpass komplext men även baserat på hoppet av att hitta en ’bästa’ möjliga definition. Begreppsutredande studier sägs kunna skapa ordning i en existerande diskussion vilket kan ses som den främsta anledningen valet av den i denna uppsats.Resultatet av studien och denna uppsats är att det är i stort sett omöjligt att etablera en bästa definition av begreppet environmental security, samt att en annan metod förmodligen hade presenterat ett annat resultat.