Dissertations / Theses on the topic 'Mine residues'

Research has demonstrated that mining activities can cause serious impacts on the environment, as well as the surrounding communities, mainly due to the unsafe storage of mine tailings. This research focuses on the sustainability assessment of new technologies for the recovery of metals from mine residues. The assessment consists in the evaluation of the environmental, economic, and social impacts through the Life Cycle based methods: Life Cycle Assessment (LCA), Life Cycle Costing (LCC), and Social Life Cycle Assessment (SLCA). The analyses are performed on the Mondo Minerals bioleaching project, which aim is to recover nickel and cobalt from the Sotkamo and Vuonos mine tailings. The LCA demonstrates that the project contributes to the avoided production of nickel and cobalt concentrates from new resources, hence reducing several environmental impacts. The LCC analysis shows that the company’s main costs are linked to the bioleaching process, caused by electricity consumption and the chemicals used. The SLCA analyses the impacts on three main stakeholder categories: workers, local community, and society. The results demonstrated that a fair salary (or the absence of it) impacts the workers the most, while the local community stakeholder category impacts are related to the access to material resources. The health and safety category is the most impacted category for the society stakeholder. The environmental and economic analyses demonstrate that the recovery of mine tailings may represents a good opportunity for mine companies both to reduce the environmental impacts linked to mine tailings and to increase the profitability. In particular, the project helps reduce the amounts of metals extracted from new resources and demonstrates that the use of the bioleaching technology for the extraction of metals can be economically profitable.

Major impacts of current and pre-regulatory mining activities on the environment include the generation of acid mine drainage (AMD) and metal(loid)-laden acid sulfate soils. Current remediation techniques are mostly cost prohibitive due to high energy, material, and labor requirement. This study investigated two complementary low-cost methods that harnessed the metal(loid)-removing and acid-neutralizing properties of drinking water treatment residuals (WTRs) and the uptake (phytoremediation) potential of vetiver (Vetiviera zizanioides L.) and pokeweed (Phytolacca americana L.) to attenuate and immobilize metal(loid)s from natural AMD and metal(loid)-contaminated soil. Metals were removed from AMD by using a reverse flow fluidized column filter and hydroponic phytoremediation with vetiver and pokeweed. Metals were immobilized in soil through the amendment with Fe and Ca-WTR complimented by the uptake and translocation of metals by vetiver and pokeweed. Experiments were performed under controlled greenhouse conditions as well as under natural Illinois environment in simulated field conditions. Furthermore, the integrated effects of WTR application and the growth of vetiver on soil erosion were also studied. Physicochemical analysis of AMD and soil samples from the Tab-Simco abandoned mine in the Illinois Coal Basin, U.S.A, showed significant concentrations of major metals and metalloids such as Fe, Al, Mn, Zn, Ni, Cu and As at acidic pH levels. The degree of soil contamination at the site was spatially variable with respect to the location of the main AMD seep. Physical, chemical, agronomic and mineralogical characterization of locally acquired water treatment residuals (WTR) showed that the silty and alkaline (pH ≈ 7.0-9.1) materials also contained significant amounts of plant required micronutrients. The presence of amorphous phases of mostly metal (oxy)hydroxides, alkalinity, and porosity of the WTRs suggested the potential to neutralize acidity and capability to remove metal(loid)s in contaminated soils and AMD. Recorded metal removal (%MR) rate by WTR was rapid in the first 80 min in a batch agitation study, except for Mn. Thus, high metal removal ranging from 99.8% to 84.9% at selectivity sequence of Al>Fe>Cu>Zn and Mn (9.6%) was obtained at equilibrium. The pH of the AMD was also increased from 2.6 to 6.7. Analysis of leachate samples from gravity-drained columns following simulated rain events in a greenhouse study showed reduced concentrations of Al, Fe, Mn, Zn, Cu, As and Pb at sustained neutral pH compared with unamended control columns during the 12 weeks study period. Metal immobilization in soil by the lower amendment rates of WTR was comparable to the higher application rates and also showed lower oxalate extractability of metals. Tissue analysis of pokeweed and vetiver hyperaccumulators showed appreciable uptake of relevant elements although translocation was relatively low in both. The analytical results at the greenhouse scale was reproducible in a simulated field scale study under natural Illinois environmental condition where the best amendment rate including 50 g/kg Fe-WTR and 15 g/kg of Ca-WTR and manure helped to improve metal(loid) retention, soil structure and enhanced vetiver growth which subsequently aided in reducing the rate of erosion to levels comparable to bermudagrass which was used as control. The developed integrated WTR fluidized column and phytoremediation technique with vetiver and pokeweed under hydroponic conditions sequentially removed significant quantities of most heavy metals from AMD. Thus, the overall findings showed that the locally collected WTRs - the otherwise waste materials, showed high metal-removing and acidity-reducing capabilities in AMD and contaminated soil treatment applications. The similarity between the results obtained from the laboratory and simulated field study also showed that laboratory/greenhouse experiments may serve as reliable proxies for field responses in applications such as soil and water conservation in agricultural environments, remediation of abandoned mine lands, as well as wastewater treatment systems.

In South Africa, being the second largest global coal exporter, coal mining plays a pivotal role in the growth of our economy, as well as supplying our nation’s ever increasing electricity needs; while also accounting for more than 10% of the 20 x 109 m3 water used annually in the country. Coal mining may thus be classified as a large-scale water user; known to inevitably generate wastewater [acid mine drainage (AMD)] and other waste material, including fly ash (FA). Current and conventional AMD treatment technologies include precipitation–aggregation (coagulation/flocculation) – settling as hydroxides or insoluble salts. The process stream resulting from these precipitation processes is still highly saline, therefore has to undergo secondary treatment. The best available desalination techniques include reverse osmosis (RO), electro dialysis (ED), ion exchange and evaporation. All available treatment methods associated with raw AMD and its derived process stream fall prey to numerous drawbacks. The result is that treatment is just as costly as the actual coal extraction. In addition, remediation only slows the problem down, while also having a short lifespan. Research conducted into converting fly ash, an otherwise waste material, into a marketable commodity has shown that direct mixing of known ratios of FA with AMD to a pre-determined pH, erves a dual purpose: the two wastes (AMD and FA) could be neutralized and produced a much cleaner water (secondary co-disposal [FA/AMD]-process water), broadly comparable to the process water derived from precipitation-aggregation treated AMD. The collected post process solid residues on the other hand, could be used for production of high capacity ion exchange material (e.g. zeolite A, faujasite, zeolite P, etc.). The produced ion exchange material can subsequently be utilized for the attenuation of metal species in neutralized FA/AMDprocess waters.
Magister Scientiae - MSc

Mining industry faces environmental problems concerning waste management. Given the environmental issues associated with storage of mine wastes on land, one disposal option that has gained attraction is submarine tailings disposal (STD). This practice involves disposal of mine tailings under seawater through underwater pipelines. Discharged mine wastes may be geochemically altered by microbial communities that living in the seabed have an ecophysiology that is compatible with the mine tailings. These communities (e.g., Shewanella, Geobacter) would be able to reduce the structural Fe(III) of oxides and oxyhydroxides (henceforth referred to as (hydr)oxides) of iron contained in the tailings, leading to a release of Fe(II) and Trace Elements (TEs) into the marine environment. The present study aimed at understanding the reaction of bioreduction of iron (hydr)oxides that are contained in mine tailings and assessing the environmental impact of STD. For this purpose, different samples of iron (hydr)oxides and mine tailings were reacted in batch and column experiments in the presence of Shewanella loihica, a dissimilatory iron reducing bacteria. The release of Fe(II) and TE was monitored throughout the experiments, and the surface of the reacted oxides were examined. Geochemical simulations of the experimental data were used to quantify the extent of the overall reductive dissolution reaction. Furthermore, to understand the influence of aqueous iron in the ocean’s nitrogen cycle, a series of experiments were carried out with Fe(II) released from bioreduced iron oxides in the presence of nitrite. Results showed that Shewanella loihica bioreduces Fe(III) from the iron (hydr)oxides contained in the mine tailings under marine conditions. The dissolution process leads to a release of Fe(II) and TEs, which are harmful for the marine environment. It was deduced that the reactive surface area of the iron (hydr)oxides is a key factor in the bioreduction process as it provides available Fe(III) and available surface, on which Shewanella loihica attach for electron transferring. However, adsorption of some of released Fe(II) onto the surface leads to a decrease in the reactive surface area, which lowers the total available Fe(III), and to a transformation of the former oxide to a new biogenic phase containing Fe2+/Fe3+ (i.e. magnetite). Moreover, it was demonstrated that the Fe(II) released promotes a nitrite removal, interfering thus with the nitrogen cycle of the ocean. The nitrite removal was characterized using chemical and isotopic analyses, which allowed a better understanding of the mechanisms controlling the Fe(II)-N interaction and an identification of the source of nitrite reduction in the sea. From the results, it is inferred that STD can become a major environmental concern because (1) the Fe(II) released may lead to fertilization and eutrophication of disposal sites, resulting in an oxygen depletion and an expansion of the oxygen minimum zone and (2) the TEs released bioaccumulate in the environment and trophic webs, ultimately affecting human health and social economic development.
La indústria minera s’encara a un problema de gestió dels residus produïts. Degut als problemes mediambientals que provoca l’emmagatzematge terrestre de les cues mineres, la deposició submarina de les cues (STD) és una opció que ha guanyat interès en els darrers anys. Aquesta pràctica implica el dipòsit dels residus al fons marí mitjançant canonades submergides des de les indústries mineres. Aquestes cues es poden veure afectades geoquímicament per les poblacions microbianes que viuen en el fons marí i que poden tenir una ecofisiologia compatible amb els residus. Aquestes comunitats (per exemple, Shewanella, Geobacter) poden bioreduir el ferro fèrric dels òxids i/o hidròxids continguts en els residus miners, alliberant Fe (II) i elements traça (TE) al medi marí. El principal objectiu d’aquest treball va ser entendre el procés de bioreducció dels òxids i hidròxids de ferro presents en els residus miners i avaluar les conseqüències mediambientals dels dipòsits de residus al fons marí. Per dur a terme aquest propòsit, es van fer experiments de tipus batch i de columna amb diverses mostres d’òxids i hidròxids de ferro i de residus miners, les quals van reaccionar amb Shewanella loihica, un bacteri desassimilatori del ferro capaç de dur a terme la dissolució reductiva del ferro. Es va monitoritzar l’alliberament de Fe(II) i de TEs, es van observar les superfícies dels sòlids reaccionats i es va fer un model geoquímic per quantificar la bioreducció. A més a més, per tal d’entendre millor la influència del ferro en el cicle del nitrogen de l’oceà es van dur a terme uns experiments batch on el ferro bioreduït interaccionava amb nitrit. Els resultats han demostrat que la Shewanella loihica pot bioreduir els òxids i/o hidròxids de ferro continguts en residus miners en condicions semblants a les del fons marí. Aquesta dissolució bioreductiva comporta l’alliberament de Fe(II) i de TEs que poden arribar a ser perjudicials per l’ambient. S’ha deduït que la superfície reactiva dels òxids i/o hidròxids é un factor clau en la bioreducció perquè proveeix Fe(III) per bioreduir i superfície perquè els bacteris transfereixin electrons.. Ara bé, l’adsorció de Fe(II) en la superfície comporta, per una banda, la disminució de la superfície reactiva i del Fe(III) disponible i, per altra banda, la formació d’una nova fase mineral biogènica que conté Fe2+/Fe3+, és a dir una transformació a magnetita També s’ha demostrat que el Fe(II) alliberat per la bioreducció pot interferir, amb el cicles biogeoquímic del nitrogen de l’oceà. Així, el Fe(II) bioproduït desencadena l’eliminació del nitrit en el mar. Aquest procés s’ha caracteritzat utilitzant anàlisis químiques i isotòpiques. Les dades isotòpiques han servit per entendre millor els mecanismes que regulen la interacció Fe(II)-nitrogen, i per identificar l’origen de la reducció de nitrit en el medi marí. A partir dels resultats obtinguts, es dedueix que el dipòsit de residus miners al mar (STD) és un problema mediambiental perquè (1) l’alliberament de Fe(II) pot provocar una fertilització i eutrofització dels llocs on es dipositin els residus amb una disminució de l’oxigen dissolt i una expansió de la zona mínima d’oxigen i (2) l’alliberament d’ETs pot provocar una bioacumulació d’aquests elements a les xarxes tròfiques. Tot plegat afecta no només l’equilibri d’altres cicles biogeoquímics a l’oceà sinó també la salut humana i l’economia de la societat.

Surface mining is important to our modern way of life and to coal mining in the United States of America. Unfortunately old and new surface mining sites produce a metal-rich acidic solution termed acid mine drainage (AMD), which contaminates water and soil. Acid sulfate soil is unstable and prone to erode, and spreading this acidic sulfate–rich liquid across mine sites may increase the amount of AMD that can be generated. The current study focused on evaluating two affordable passive treatments of AMD and AMD-impacted water which could be used together to construct a semipermeable membrane for erosion control of acidic soils, immobilization of heavy metals, and to increase the pH. The first treatment was the land application of an inexpensive industrial by-product, drinking water treatment residuals (WTRs) to treat AMD with its alkalinity and metal binding affinity. The second treatment, intended for placement behind the WTR to clean metal-contaminated water and provide erosion control was the perennial grass, sunshine vetiver (Chrysopogon Zizanioides). Sunshine vetiver is fast-growing, non-invasive, extremely tolerant of adverse AMD conditions, and a hyperaccumulator of some metals. In this experiment, all the sunshine vetiver grasses were able to grow in the practical mixtures of WTR and AMD-soil considered. With exposure to acidity the investigated WTRs released greater amounts of toxic heavy metals, the RCRA8 metals and aluminum, than ideal for use as a soil amendment on AMD sites. i

La presente tesis tiene como propósito identificar la alternativa óptima de tratamiento de efluentes de mina tomando como base la caracterización física-química de los drenajes, la caracterización geoquímica de materiales mineros y la evaluación en laboratorio de alternativas de tratamiento. En el Capítulo 1 a modo de Introducción se realiza una breve descripción de la situación actual del país respecto de los drenajes de mina, abarcando desde el daño ambiental producido por pasivos mineros hasta los distintos conflictos sociales que hoy en día han detenido más de 20,000 millones de dólares de inversiones en el sector. En el Capítulo 2 se desarrolla el Marco Teórico del tema donde se describe los mecanismos de formación del drenaje ácido, su caracterización, control y la descripción de sus distintos tratamientos tanto activos como pasivos. En el Capítulo 3 se describe el Marco Legal actual del país en relación al manejo de efluentes en el Sector Minero. Teniendo en cuenta que para el desarrollo de la tesis se han utilizado materiales y efluentes de dos unidades mineras, en el Capítulo 4 se describe la ubicación de estas y sus características ambientales más representativas. En el Capítulo 5 se describe el Desarrollo Experimental de la tesis que abarca la caracterización de materiales y efluentes provenientes de cada unidad minera, los ensayos de laboratorio a los que fueron sometidos los efluentes para determinar los rangos de operación de los procesos de neutralización, precipitación y remoción de las fases solidas formadas y la elección de la alternativa de tratamiento óptima para cada efluente. Para finalizar en el Capítulo 6 se plasman las conclusiones y recomendaciones planteadas luego del desarrollo de la presente tesis.
Tesis

Large quantities of tailings are produced during gold and coal mining activities. These tailings consist of ash dumps, waste rock dumps, in-pit deposits and any other heap, pile or accumulation of residue in the tailings or slimes dams. It has been reported that these tailings can have a significant impact on water quality in the vicinity of gold and coal residues in South Africa. Water quality deterioration in the vicinity of gold and coal mines in the Johannesburg and other areas has been reported. However, little information is available on the potential impact of residues on water quality near Roodepoort and Newcastle where gold and coal, respectively, are mined. The objective of this investigation was therefore to determine the potential impact of gold and coal mine residues on the environment in the vicinity of Roodepoort and Newcastle. Secondary objectives were to identify the metal constituents of gold and coal mine residues, to evaluate and define the current knowledge with regard to the short-term water quality impact of gold and coal residues in terms of concentration of metals leaching from the residues, to assess the potential impact of gold and coal tailings on the water environment within the study areas and to suggest methods to prevent pollution from taking place. Acid Base Accounting (ABA), Toxicity Characteristics Leaching (TCLP), Acid Rain Leaching Procedure (ARLP) and Inductively Plasma Coupled – Mass Spectrometry (IPC-MS) were used as tools to determine the potential impact of gold and coal tailings on the environment. Acid Base Accounting comprises two components that show the potential of the mine residue to produce acid mine drainage, that is, the total sulphur and the net neutralisation potential (NNP). It has been reported that any pyrite mine residue containing more than 0.5% total sulphur may generate acid mine drainage. Mine residues with a net neutralisation potential of less than zero ppt CaCO3 produce acid drainage. The acid base accounting results show that the gold and coal mine residues contain sulphur which has the potential to produce acid mine drainage. Lithium (Li), sodium (Na) magnesium (Mg), aluminium (Al), potassium (K), calcium (Ca), iron (Fe), manganese (Mn) and nickel (Ni) were identified to be present in the gold mine residue. The concentrations of some of the metals that leached from the gold residue according to the TCLP tests were as follows: Al (22 mg/L); Ca (242 mg/L); Fe (29 mg/L); Mn (88 mg/L) and Ni (87 mg/L). The metals that leached from the gold residue according to the ARLP results were as follows: Na (43 mg/L); Al (169 mg/L); Ca (246 mg/L); Fe (771 mg/L); Mn (16 mg/L) and Ni (11 mg/L). Higher concentrations of metals generally leached from the gold residue with the ARLP test than with the TCLP test. The sulphate concentration up-stream of the gold residue was determined at 225 mg/L. This concentration increased to 3 490 mg/L at the decanting point and to 11 577 mg/L downstream of the decanting point. The surface and possibly groundwater are therefore polluted with sulphates. Lithium (Li), sodium (Na), magnesium (Mg), aluminium (Al), potassium (K), calcium (Ca), iron (Fe), manganese (Mn) and nickel (Ni) were identified to be present in the coal mine residue. The concentrations of some of the metals that leached from the coal residue according to the TCLP tests were as follows: Al (3 mg/L); Ca (56 mg/L); Fe (0.21 mg/L); Mn (1 mg/L) and Ni (0.082 mg/L). The metals that leached from the coal residue according to the ARLP test results were as follows: Na (3 mg/L); Al (15 mg/L); Ca (136 mg/L); Fe (0.91 mg/L); Mn (1 mg/L) and Ni (0.07 mg/L). Higher concentrations of metals generally leached from the coal residue with ARLP test than with the TCLP test. The sulphate concentration up-stream of the coal residue was determined at 26 mg/L. This concentration increased to 3 615 mg/L at the decanting point and to 6 509 mg/L downstream of the decanting point. The surface and possibly groundwater are therefore polluted with sulphate. The upstream Na (26 mg/L), Ca (41 mg/L), Fe (0,02 mg/L), Mn (3 mg/L) and Ni (0.065 mg/L) concentrations were low in the case of the gold residues. These concentrations at the decanting point were: Na (289 mg/L); Ca (266 mg/L); Fe (0.2 mg/L); Mn (0.01 mg/L) and Ni (2 mg/L). Fifty metres downstream these concentrations were: Na (140 mg/L); Ca (389 mg/L); Fe (722 mg/L); Mn (395 mg/L) and Ni (15 mg/L). There was a significant increase in the metal concentration from up-stream of the gold residue, to the decanting point and further downstream of the gold residue. The surface and possibly ground water are therefore polluted by the metals leaching from the gold residue. The upstream Na (5 mg/L), Ca (8 mg/L), Fe (0,12 mg/L), Mn (0.015 mg/L) and Ni (0.05 mg/L) concentrations were low in the case of the coal residues. These concentrations at the decanting point were: Na (189 mg/L); Ca (337 mg/L); Fe (68 mg/L); Mn (13 mg/L) and Ni (0.06 mg/L). Fifty metres downstream these concentrations were: Na (65 mg/L); Ca (129 mg/L); Fe (0.48 mg/L); Mn (5 mg/L) and Ni (0.06 mg/L). There was a significant increase in the metal concentration from up-stream of the coal residue, to the decanting point and further downstream of the coal residue. The surface and possibly ground water are therefore polluted by the metals leaching from the coal residue. The gold and coal mine residues are polluting the surface and possibly ground water. Therefore, in order to ameliorate the current status within the Roodepoort and Newcastle catchments, mitigation and management measures such as that the residues should be covered and capped with soil material that would prevent infiltration of the oxygen and rain water into the soil, are recommended. A more comprehensive water quality analysis of the surroundings of the residues is also suggested to be able to better quantify the extent of the problem. Copyright
Dissertation (MSc)--University of Pretoria, 2011.
Chemical Engineering
Unrestricted

[Truncated abstract] Industrial processing to refine alumina from bauxite ore produces millions of tonnes of refining residue each year in Australia. Revegetation of bauxite residue sand (BRS) is problematic for a number of reasons. Harsh chemical conditions caused by residual NaOH from ore digestion mean plants must overcome extremely high pH (initially >12), saline and sodic conditions. At such high pH, manganese (Mn) is rapidly oxidised from Mn2+ to Mn4+. Plants can take up only Mn2+. Thus, Mn deficiency is common in plants used for direct BRS revegetation, and broadcast Mn fertilisers have low residual value. Added to this, physical conditions of low water-holding capacity and a highly compactable structure make BRS unfavourable for productive plant growth without constant and large inputs of water as well as Mn. However, environmental regulations stipulate that the residue disposal area at Pinjarra, Western Australia, be revegetated to conform with surrounding land uses. The major land use of the area is pasture for grazing stock. Hence, pasture revegetation with minimum requirement for fertiliser and water application is desirable. This thesis investigates a number of avenues with potential for maintaining a productive pasture system on BRS whilst reducing the current level of Mn fertiliser and irrigation input. Emphasis was placed on elucidation of chemical and physical factors affecting Mn availability to plants in BRS

>Magister Scientiae - MSc
Coal-fired power stations produce large volumes of coal combustion residues (CCRs), which are disposed of in hold ponds or landfill sites. These ash storage facilities are limited in space and are approaching the end of their capacities, thus additional land is required for extensions. If new land is not sourced, power plants will be forced to cease operations, resulting in increased expenditure costs and environmental liability. A proposed disposal solution is to backfill opencast coal mines with CCR monoliths. However, there is limited knowledge on the hydraulic behaviour of CCRs in an opencast coal mine environment. This leads to an inability to assess this applications feasibility and determine whether this activity will have a positive, negligible or negative effect on groundwater quality. This study aims to address this gap in knowledge by assessing the flow and transport properties of CCRs under numerous theoretical backfilling conditions.

This study reviews the requirements for an effective reliable inspection and discard policy based on monitoring the condition of ropes used in Indian mines. This contrasts with current practice which is based upon a policy of 'Statutory Life Policy'. Data have been collected data on rope service to study the influence of operating parameters on the degradation mechanisms affecting hoisting ropes in Indian mines. In addition to this, records on failed/premature discarded hoisting ropes from Indian mines have been also collected to classify the prominent causes of failure in terms of operating parameters. These data include 645 records of ropes (606 from 303 drum winders and 39 from 11 friction winders) which have been In service, and 45 records of failure and premature discard categorized in terms of different parameters. These data inform the proposed recommendations for policy to minimised failure through the adoption an efficacious inspection procedure.

Menopause is associated with disorders such as osteoporosis and ovarian cancer. It is unclear whether the postmenopausal ovary retains steroidogenic capacity and how it can impact the development of these disorders. The present studies used the VCD-treated follicle-depleted mouse model of menopause to test the hypothesis that residual ovarian tissue retains steroidogenic capacity following ovarian failure and, thus, affects the development of these disorders. Microarray technology was used to evaluate gene expression in residual ovarian tissue of follicle-depleted mice compared to that in ovaries from cycling animals. Among the genes identified were those encoding proteins for synthesis of androgens. Steroidogenic capacity of residual ovarian tissue was further evaluated by determining the expression of genes and proteins involved in ovarian steroidogenesis, and by measuring levels of circulating and rostenedione and gonadotropins. Follicle-depleted ovaries were enriched in mRNAs for androgenic enzymes, receptors involved in the internalization of cholesterol, and luteinizing hormone receptor. Increased circulating levels of FSH and LH and detectable and rostenedione were measured throughout the study. Protein for 3β-hydroxysteroid dehydrogenase, 17α- hydroxylase/17,20-lyase and luteinizing hormone receptor was detected in follicledepleted ovaries by Western blot analysis and localized by immunofluorescence staining. The contribution of retaining residual ovarian tissue to accelerated bone loss following ovarian failure was evaluated by comparing bone mineral density from young and aged VCD-treated mice to that in age-matched ovariectomized (OVX) animals. Retaining residual ovarian tissue resulted in protection against accelerated bone loss in young but not aged VCD-treated mice. Whether residual ovarian tissue is more susceptible to development of ovarian neoplasms compared to ovaries from cycling animals was addressed by combining the VCD-treated mouse with the DMBA model of ovarian carcinogenesis. VCD-treated follicle-depleted mice that received DMBA developed Sertoli-Leydig cell tumors while no tumors were observed in cycling animals. Residual ovarian tissue following ovarian failure appears to have a protective effect against loss of bone integrity, but a detrimental effect on development of ovarian neoplasms. Findings from these studies: provided evidence of a physiological role for residual ovarian tissue following ovarian failure, and furthered the use of the VCD-treated mouse as a relevant model for menopause and associated disorders.

La memoria titulada "Desarrollo de un nuevo método para la eliminación de cianuro de aguas residuales de mina" que se presenta como tesis doctoral contiene resultados de relevancia. Durante el trabajo realizado se han estudiado aguas cianuradas de mina con objeto de encontrar un proceso de detoxificación de los complejos cianurados de cobre principalmente, alternativo a los ya existentes. Se ha desarrollado un método oxidativo con permanganato potásico como agente oxidante, con el que se han conseguido resultados muy favorables, permitiendo la reducción de la contaminación hasta niveles exigidos actualmente por la legislación vigente para envío a cauce público. Además de los estudios de laboratorio propiamente dicho, se ha diseñado una planta piloto en una instalación minera próxima lo que ha permitido la verificación de la utilidad industrial del proceso planteado. El tema abordado es de gran interés, ya que las aguas residuales cianuradas constituyen un verdadero problema para las empresas generadoras por su elevada toxicidad ambiental, por lo que invierten elevadas cantidades de dinero en su control y eliminación. Por otra parte, la valoración económica del procedimiento desarrollado en este trabajo en comparación con otros métodos ya existentes, ha demostrado su competitividad a nivel industrial.

Doutoramento em Engenharia do Ambiente - Instituto Superior de Agronomia - UL
Neste trabalho estudou-se a potencial reabilitação de dois tipos de escombreiras, rica em sulfuretos e gossan, da mina de São Domingos usando resíduos orgânicos/inorgânicos e espécies vegetais com valor económico, Cistus ladanifer (esteva) e Lavandula pedunculata (rosmaninho). Avaliou-se o comportamento ecofisiológico das espécies em condições naturais e a qualidade de alguns produtos derivados das mesmas (chá/infusão de rosmaninho e bioextractos de ambas as espécies) face às características dos substratos onde estas crescem espontaneamente. Em condições controladas, avaliou-se a eficiência de Tecnossolos, elaborados com resíduos orgânicos/inorgânicos e de escombreiras, na melhoria da qualidade química dos lixiviados (percolação e simulados), para minimizar a dispersão dos contaminantes, e melhorar as características químicas e biológicas dos materiais para desenvolvimento de vegetação. Independentemente das características dos solos, ambas as espécies crescem sem sinais de toxicidade ou deficiência nutricional apresentando características ecofisiológicas adequadas para fitoestabilização. Nas duas espécies, o primeiro mecanismo de tolerância aos elementos potencialmente tóxicos (EPTs) do solo é a sua acumulação na raiz e baixa translocação para locais fotossinteticamente activos. As concentrações fitotóxicas de alguns elementos na parte aérea do rosmaninho não afectaram a concentração de pigmentos e proteínas nem desencadearam mecanismos de tolerância, enzimáticos e não enzimáticos, relacionados com stresse oxidativo. Os produtos derivados das plantas crescendo na área mineira apresentaram viabilidade económica para diferentes usos pois mantêm a sua qualidade comparada com as de áreas controlo. As escombreiras ricas em sulfuretos lixiviaram soluções extremamente ácidas e com maiores concentrações de EPTs do que as escombreiras de gossan. A metodologia mais sustentável para a reabilitação de ambas as escombreiras da mina de São Domingos foi o desenvolvimento de um sistema que combina o isolamento natural dos materiais ricos em sulfuretos, com uma barreira de resíduos carbonatados, e fitoestabilização com esteva e/ou rosmaninho dos Tecnossolos elaborados com materiais de gossan e resíduos orgânicos/inorgânicos

La Mina Invicta se encuentra ubicada en la provincia de Huaura, departamento de Lima, a a 320 km y cuatro horas de la ciudad de Lima, y a una altitud de alrededor de 3600 msnm. Para el tratamiento del mineral se ha considerado una planta concentradora, con una capacidad de tratamiento máximo de 5100 TM/día. Respecto de la disposición de los relaves, que se producen como consecuencia del trabajo minero. En primera instancia, se dispone que sean deshidratados y colocados en la relavera denominada ¨A¨ sin embargo de ocurrir algún inconveniente, como una baja en la tensión eléctrica o parada en los espesadores o bombas, se hace necesario disponer de una medida de contingencia, sin que esto signifique parar las operaciones en planta por lo que es necesario un sistema alterno que entre en funcionamiento de manera inmediata, destinando los relaves desde el tanque de paso en planta hacia un Echadero o distribuidor y de allí a la relavera de contingencia, también denominada relavera ¨B¨, el objeto del presente trabajo es precisamente el cálculo para el sistema de bombeo, del relave, que determina finalmente el uso de una bomba tipo HM 150 (Metso minerals), de aleación de cromo y con una eficiencia del 67.9%, la cual bombeara 2.69 pies cúbicos por segundo de relave con una densidad de la pulpa de 1.5 y una gravedad especifica Gs: 2.89, en máxima producción; desde la planta ubicada en la cota 2300 a través de 300 metros de tubería de HDPE de 8” SDR 11, hacia el Echadero distribuidor ubicado en la cota 2350, con un volumen de 3770 m3. Pudiendo contener más de 13 horas el flujo y desde allí distribuirlo a los espesadores o derivarlo a la relavera de contingencia denominada relavera ¨B¨.

MinC is the principle inhibitor of cell division in the Gram negative coccus Neisseria gonorrhoeae. Multiple alignment of 28 minC homologues from prokaryotic organisms revealed the conservation of four glycines in the C-terminus. Radical mutations of these residues, G138D, G157D, G164S, and G174E, were introduced to minCNg using site-directed mutagenesis and were expressed heterologously in Escherichia coli. Microscopic analysis of cellular morphology revealed abrogation of MinCNg function as indicated by the inability of the overexpressed protein to induce filamentation, and flow cytometry substantiated these data. The radical mutation of a non-conserved residue was also performed, and no impact on MinCNg function was observed. Circular dichroism was employed to confirm the preservation of protein structure in all mutants. Using the crystal structure of MinC from Thermotoga maritima, the position of the mutations of conserved and non-conserved residues was ascertained. The glycine residues were thus demonstrated to be of paramount importance to protein functionality and their conservation indicates a role for these residues in MinC function among bacterial species. The N-terminus of MinCNg is not conserved across species, but contains common structural motifs that were similarly mutagenized with moderate effect on the resultant protein as ascertained using similar methodology. Truncations of MinCNg revealed the necessity of the thirteenth amino acid for division inhibition function. Although the first ten amino acids were not necessary for protein function, the resultant protein was expressed and present in abundance, implicating a role for the extreme N-terminal region in protein stability. Plasmids for MinCNg localization and purification were also constructed to facilitate future experimentation.

Mestrado em Toxicologia
A contaminação de ecossistemas naturais, resultante da actividade do Homem, é um problema que assume cada vez maior relevância ecológica. Em particular a indústria mineira, envolve profundas modificações (e.g., paisagísticas, químicas, biológicas) que podem provocar grandes impactos ambientais. Assim, a exploração mineira pode provocar a acumulação de metais pesados na coluna de água e nos sedimentos associados ao jazigo mineral, que são susceptíveis de determinar graves consequências ambientais. Na Mina da Cunha Baixa desenvolveu-se, até cerca de 1993, a exploração de minérios radioactivos, nomeadamente de urânio. À presença de material radioactivo (cerca de 1 milhão de tonelads de material, com níveis médios de 300 ppm de U, associado a 226Ra), associam-se metais, nomeadamente, zinco, alumínio, berílio. Com este estudo pretendeu-se avaliar a toxicidade de águas e sedimentos de uma mina de urânio com duas espécies de cladóceros (Daphnia magna e Daphnia longispina), através de ensaios agudos e crónicos e, também, com a bactéria Vibrio fischeri. Dos resultados obtidos, a espécie mais sensível nos ensaios de imobilização, foi D. longispina, quer para águas, quer para o sedimento, sendo D. magna a menos sensível. O tratamento da água, realizado no local, indicia bons resultados no referente a toxicidade da coluna de água já que é mínima, ou praticamente inexistente, em ensaios de imobilização e crónicos. Deste modo, a água que circula pelos campos agrícolas limítrofes à mina pode ser classificada como de boa qualidade para rega, visto os parâmetros observados estarem dentro dos limites propostos pela legislação. Para uma melhor avaliação toxicológica seria necessário realizar mais ensaios ao longo do ano hidrológico, pelo menos um ensaio por estação do ano. A fim de se caracterizar potenciais efeitos ou riscos ecológicos em populações naturais devem ser efectuados estudos relativamente à alteração da estrutura da comunidade, associada à realização de bioensaios com diferentes metais, para determinação de potenciais efeitos agudos e crónicos em organismos aquáticos.
The contamination of natural ecosystems resulting from Human activity is a problem with increasing ecological relevance. The mining activity, in particular, involves serious changes (e.g., landscape, chemical, biological) that may cause serious environmental impacts. Thus, the mining activity may cause the accumulation of heavy metals in the water column and in the sediments associated with the mineral beds, which are susceptible to determine serious environmental consequences. In the Cunha Baixa mine, until 1993, was performed the extraction of radioactive ore, such as uranium. Not only radioactive material was detected (about 1 million tons of material, with average levels of 300 ppm of U, associated with 226Ra), but also metals such as zinc, aluminium, and beryllium were determined. The aim of this study was to assess the toxicity of water and sediment of Cunha Baixa mine using two cladoceran species (Daphnia magna and Daphnia longispina), through acute and chronic tests and, also, using the bacteria Vibrio fischeri. According to the obtained results, the most sensitive species was D. longispina for both water and sediments immobilization assays, being D. magna the less sensitive. The treatment of water performed in situ, shows good results concerning the water column toxicity, as it was minimal, or practically inexistent in immobilization and chronic assays. Therefore, the water that circulates through the limitrophe agricultural fields to the mine can be classified as of good quality for irrigation, once the observed parameters are within the legislated limit values. For a better toxicological evaluation it would be necessary to perform more assays during the hydrological year, at least one assay per season. In order to characterize potential effects or ecological risks in natural populations, further studies should be performed concerning the change in the community structure, associated with bioassays with different metals to determine the potential acute and chronic effects in aquatic organisms.

Thesis (Ph.D. in Immunology) -- University of Colorado Denver, 2008.
Typescript. Includes bibliographical references (leaves 138-153). Free to UCD Anschutz Medical Campus. Online version available via ProQuest Digital Dissertations;

Publicación a texto completo no autorizada por el autor
Determina en qué medida la aplicación del tratamiento de aguas residuales industriales mediante el sistema de pasivos artificiales (wetland), y su posterior recirculación, disminuirá significativamente el nivel de contaminación ambiental generado por las aguas acidas y metales pesados en la mina San Genaro y la comunidad campesina de Santa Ana, ubicadas en Huancavelica, Perú. Determina en qué medida la aplicación del tratamiento de aguas residuales industriales mediante pozas de decantación y sistema tipo wetland y su posterior recirculación, disminuirá significativamente el nivel de contaminación ambiental, generado por metales pesados y otros componentes, de modo que cumplan con los parámetros ambientales establecidos por las leyes peruanas. Determina si la aplicación del tratamiento de aguas residuales industriales mediante pozas de oxidación y sistema tipo wetland, y su posterior recirculación será mucho más económico que un sistema de tratamiento tradicional.
Tesis

Access to energy is crucial to human welfare; no residential, commercial or industrial activity can be conceived without energy supply. At the same time, current dependence on fossil fuels and their negative effects on global climate claim for urgent alternatives. The situation in Sub-Saharan Africa is poignant: over half of the population, mainly in rural areas, live without access to electricity services. Crop residues from farming communities in those areas are unused; while technology for electricity production from agricultural biomass is progressing, managing decentralised rural electricity projects is still a challenge, especially in developing countries like Ghana, given the variety and complexity of the factors conditioning biomass to energy supply chains. Such complexity has been previously formulated in academic exercises, but with limited practical applicability for energy planners, practitioners and investors. This research has deployed a holistic approach to biomass-to-energy planning, yet flexible to adapt to different regulatory scenarios and energy supply configurations. A qualitative framework has been developed, taking into consideration four critical components: social development, organisational/institutional, technical, and financial, with their respective metrics. Then, the framework has been applied to three real case study configurations in Ghana, involving primary data collection, sustainability modelling and discussion of the techno-economic feasibility results with policy makers and practitioners. The first configuration consists in decentralised power generation using crop residues from clustered smallholder farms in 14 districts in Ghana; the number of clustered farms, reference residue yields, and residue densities are determined to assess the distances within which it would be feasible to supply feedstock to biomass power plants. The findings show that a minimum of 22 to 54 larger (10 ha) farms would need to be clustered to enable an economically viable biomass supply to a 1000 kWe plant. Financial analyses indicate that such investment would not be viable under the current renewable feed-in-tariff rates in Ghana; increased tariff by 25% or subsidies from a minimum 30% of investment cost are needed to ensure viability using internal rate of return as an indicator. Carbon finance options are also discussed. The second configuration focuses on co- and tri-generation from clustered crop residues. Techno-economic results show that 600 kW and 1 MW biomass fuelled plants to generate power, heating (for cassava or maize drying) and cooling (to refrigerate tomatoes) are feasible, considering a minimum 20% yearly profit for investors’ equity. Additional income between 29 and 64 US $/tonne of crop residue would be possible for farmers if a minimum of 60% of the heat produced can be traded. The consideration of carbon financing under the most common traded prices has little impact on the project results; if more favourable schemes (like the Swedish carbon tax) are considered, the viability of co- and tri-generation plants run on agro residue can be possible even with a low level of residual heat sales. The third configuration analyses minigrid electricity generation and services based on biomass gasification in five Ghanaian communities. Results show that the projected electricity demand compares favourably with the potential supply from available crop residues. Project financing via 100% private funding would not be viable under current national uniform tariffs; however, by applying an end-user tariff equal to the current expenditure on electricity-equivalent uses in the communities, a subsidy of about 35% on initial investment would enable a private entrepreneur an internal rate of return of 15%, whereas a 60% subsidy could enable internal rate of return of 25%. The outcomes of this research have triggered the interest of Ghanaian and international policy makers, developers and private investors.
L'accés a l'energia és crucial per al benestar humà, no es pot concebre cap activitat residencial, comercial o industrial sense subministrament d'energia. Alhora, la dependència actual dels combustibles fòssils i els seus efectes negatius sobre el clima global reclamen alternatives urgents. La situació a l'Àfrica Subsahariana és punyent: més de la meitat de la població, principalment rural, viu sense accés a serveis elèctrics. Tanmateix, en aquestes zones abunden les restes agrícoles. Tot i que la tecnologia per a la producció d'electricitat a partir de biomassa agrícola avança, la promoció de l’electrificació rural descentralitzada continua sent un repte, especialment en països en desenvolupament com Ghana, atesa la varietat i la complexitat de factors que condicionen l’aprofitament energètic de la biomassa. Aquesta complexitat s'ha tractat en exercicis acadèmics, però amb poca aplicabilitat pràctica per a planificadors d'energia, promotors i inversors. A fi de contribuir a una millor planificació i presa de decisions, aquesta Tesi desplega un marc integral d’anàlisi tenint en compte quatre components (desenvolupament social, organitzatiu/institucional, tècnic, i financer), flexible per adaptar-se a diferents configuracions de subministrament d'energia i escenaris reguladors. Aquest marc s'ha aplicat a tres casos reals a Ghana, recollint dades de camp, modelitzant la viabilitat tecno-econòmica i debatent els resultats amb promotors públics i privats. La primera configuració consisteix en la generació elèctrica a partir de restes agrícoles de petites plantacions rurals, en 14 districtes a Ghana, on s?ha determinat la biomassa disponible i la seva localització per calcular les distàncies màximes que permetrien la rendibilitat de petites centrals elèctriques. Els resultats indiquen que un mínim de 22 a 54 plantacions (de 10 ha. cadascuna) haurien d'agrupar-se per permetre un subministrament de biomassa econòmicament viable a una planta de 1000 kWe. Financerament aquesta inversió no seria viable amb les tarifes actuals d’injecció a xarxa; un increment d’aquesta tarifa en un 25%, o bé una subvenció mínima del 30% del cost d'inversió són necessàries per garantir la viabilitat. La segona configuració se centra en la co- i la tri-generació a partir de restes agrícoles. Els resultats de l’anàlisi tècnic-econòmica mostren que centrals de 600 kW i 1 MW per autogenerar electricitat, calor (per assecar mandioca o de blat de moro) i fred (per refrigerar tomàquets) són factibles, fins i tot aportant un retorn anual mínim del 20% per a inversors externs. A més de l’electricitat, en cas de poder vendre com a mínim un 60% de la calor produïda, es podria pagar entre 29 i 64 USD per tona de biomassa. La consideració de bons de carboni a preus habituals de mercat internacional té poc impacte en els resultats del projecte; si es consideren esquemes més favorables (com els bons de carboni a Suècia), la viabilitat de les plantes de co-i tri-generació a partir de restes agrícoles seria possible fins i tot amb un baix nivell de vendes de calor residual. La tercera configuració tracta el servei elèctric amb microxarxes basades en la gasificació de restes agrícoles de comunitats rurals. Els resultats de l’anàlisi en 5 comunitats mostren que el potencial de generació elèctrica a partir de la biomassa disponible supera la demanda elèctrica projectada. El finançament només a partir d’aportacions privades no seria viable amb les tarifes nacionals de consum elèctric actuals; en canvi, si s’aplica una tarifa de consum igual a la despesa actual en usos equivalents a l’electricitat (p.ex. llanternes i piles, bateries de cotxe), una subvenció del 35% sobre la inversió inicial permetria una taxa interna de retorn del 15% a inversors privats, mentre que un 60% la subvenció permetria una taxa interna de retorn del 25%.Els resultats d'aquesta investigació han estat considerats pels grups d'interès de Ghana dins de la formulació de polítiques i regulacions d'electrificació rural, i perspectives de trigeneració i els minigresos de biomassa també han desencadenat l'interès dels inversors privats internacionals i ghanesos

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas. Programa de Pós-Graduação em Química
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O presente trabalho objetivou utilizar rejeito de mineração de carvão calcinado como adsorvente para redução da acidez e remoção de íons de metais em drenagem ácida de mina de carvão. O processo de remediação da drenagem ácida foi avaliado, utilizando-se ensaios de toxicidade em organismos bioindicadores. Os resultados de caracterização do adsorvente indicaram a predominância de mesoporos e presença dos óxidos majoritários SiO2, Al2O3 e Fe2O3. A remediação da drenagem ácida com o adsorvente por processo estático foi capaz de provocar a elevação do pH e promover expressiva remoção dos íons de metais em solução. Nos estudos de adsorção de íons, constatou-se que o modelo de pseudo segunda-ordem foi o que melhor correlacionou os dados cinéticos experimentais, sendo que a isoterma de Langmuir forneceu o melhor ajuste dos dados experimentais de equilíbrio. A drenagem ácida não remediada apresentou expressiva toxicidade aguda sobre Daphnia magna e Artemia sp, bem como, elevada toxicidade subaguda em Allium cepa L, sendo que após a remediação com o adsorvente, não foi observada toxicidade para estes organismos. A remediação também promoveu a redução de dano oxidativo sobre lipídeos, proteínas e DNA em Allium cepa L. A partir dos resultados obtidos, sugeriou-se a utilização do adsorvente como alternativa para o tratamento destas fontes de contaminação ambiental.

En la actualidad las empresas, asociaciones, grupos de personas o incluso cualquier persona natural, se han visto en la necesidad de establecer acciones con respecto al medio ambiente, tales como la disminución de explotación de recursos naturales, uso de energías renovables, entre otros. La Asociación Sierra Norte Minas (ASNM) dedicada principalmente a la producción de café orgánico de variedad arábica, se ubica en el departamento de Cajamarca y cuenta con aproximadamente 36 ha dedicadas a este cultivo, siendo la producción promedio de 7 182 kg/ha de la cual el 42% es pulpa de café (residuo principal) que se obtiene en el proceso de despulpado, un proceso que no se realiza de la mejor manera. La pulpa de café es arrojada a las tierras agrícolas y/o alrededores del proceso de despulpado, sin ningún tratamiento previo y al dejarse expuesta al ambiente genera problemas tanto humano como ecológico. Por ello se planteó como objetivo la generación de electricidad mediante la producción de biogás a partir de la pulpa de café para el proceso de despulpado en la ASNM. En primer lugar se realizó un diagnóstico del proceso productivo de beneficiado de café en la ASNM el cual permitió conocer la situación actual, centrándose en el proceso de beneficiado del café. Se identificó que la pulpa de café tiene un 82,5% de humedad, 21,52 de relación C/N y 4,2% de MoV. Se realizó la propuesta de producción de biogás a partir de la pulpa de café para la generación de energía eléctrica en la que es posible producir 1665 m3 de biogás generando una cantidad de energía de 9308,37 kW. Y finalmente se ve una mejora en el proceso de despulpado tanto en la disminución del costo de mano de obra en el despulpado (-37% por quintal) y el aumento en los ingresos de un 12% en la ASNM.
Tesis

A necessidade de minimizar os impactos causados por desastres, e pelos resíduos sólidos neles gerados, motivaram o desenvolvimento da gestão de resíduos de desastres em todo o mundo. Plataformas de sensoriamento remoto orbital e aeronaves tripuladas vêm sendo empregadas no auxílio à gestão de desastres e de seus resíduo, ainda que de forma restrita a casos mais extremos. O desenvolvimento tecnológico dos veículos aéreos não tripulados (VANTs), em especial os modelos civis comerciais de baixo custo, e a formulação da legislação que trata do seu uso, tem viabilizado sua aplicação em distintas áreas, dentre elas o mapeamento de precisão. A fim de analisar a aplicabilidade dessas plataformas de auxilio ao diagnóstico da geração de resíduos de desastres, foram selecionados dois conjuntos fotografias previamente obtidos com um VANT comercial quadrirotor. Em seguida, foi realizado o processamento desses dados no PhotoScan, visando a geração de mapas informativos. Buscou-se analisar a capacidade de identificação, quantificação e caracterização dos resíduos sólidos dispostos nas áreas mapeadas. Aspectos legais, econômicos e técnicos associados ao uso da ferramenta foram contemplados, afim de melhor fundamentar a aplicabilidade em questão. Os resultados indicaram relevante potencial de identificação e quantificação dos resíduos encontrados, e algumas limitações na capacidade de caracterizá-los. A atual legislação, e os aspectos econômicos e técnicos levantados favorecem a utilização de mini-VANT comercial para o uso proposto, ainda que de forma limitada à desastres onde a extensão afetada não seja demasiadamente extensa. A observância às boas praticas na escolha do equipamento, no planejamento e execução de vôo são fundamentais para a geração de mapas informativos contendo o posicionamento, o volume estimado e a composição estimada dos montes de resíduos encontrados.
The need to minimize the impacts caused by disasters, and the solid waste generated, motivated the development of methods and practices for the management of disaster residues all over the world. Orbital remote sensing platforms and manned aircraft have been used in the management of disasters and their residues, even though it restricts them to the most extreme cases. The technological development of unmanned aerial vehicles (UAVs), especially low-cost commercial civil models, and the formulation of legislation that deals with their use, has made their application viable in different areas, including precision mapping. In order to analyze the applicability of these platforms in aid of the diagnosis of disaster waste generation, two sets of photographs previously obtained with an \"off the shelf\" UAV were selected. Then, the processing of these data in PhotoScan was carried out, aiming at the generation of informative maps. It was sought to analyze the capacity of identification, quantification and characterization of the solid residues disposed in the mapped areas. Legal, economic and technical aspects associated to the use of the tool were contemplated, in order to better base the applicability on the question. The results indicated relevant potential of identification and quantification of the residues found, and some limitations in their capacity of characterization. The current legislation, and the economic and technical aspects raised favor the use of commercial mini-VANT for the proposed use, even though in a limited way to disasters where the affected extension is not too extensive. The observance of good practices in the choice of equipment, in the planning and execution of its execution are fundamental for the generation of informative maps containing the positioning, the estimated volume and the estimated composition of the amounts of residues found.

This portfolio comprises of three papers: a systematic review, an empirical study and a critical evaluation of the research process. Systematic Review: The systematic review explored the influence of psychological flexibility on physical and psychosocial functioning in adults living with chronic pain. All studies revealed psychological flexibility or individual facets of the flexibility model improved daily functioning; including change in pain-related distress; depression-related interference; psychosocial functioning and in two cases improved physical health. There is some evidence that these effects are sustained over time. Proposals for further investigations into psychological flexibility are offered, in light of the methodological limitations associated with included articles. Empirical Study: This study aimed to explore stroke survivor’s experiences of an Acceptance and Commitment Therapy (ACT) group and the elements that supported them in adjusting to stroke limitations. Thirteen participants with varying residual stroke disabilities were interviewed; responses were analysed using Grounded Theory. Central to participant’s experiences was a concern of needing to accept a changed reality following stroke. Six core categories emerged from the data around processes that help facilitate movement towards improved acceptance. This intervention was found to support most stroke survivors with adjustment; although further replication and extension of this study is warranted due to certain methodological limitations. Implications for clinical practice and service development are considered. Critical Evaluation: Critical appraisal and reflections are offered on the research process.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
Os crescentes desenvolvimentos tecnol?gicos e econ?micos convergem para a necessidade de cria??o de materiais cada vez mais eficientes, os quais buscam unir alto desempenho e baixo custo. Os comp?sitos surgem como solu??o para substitui??o de materiais convencionais, por serem desenvolvidos para aplica??es especificas, podendo apresentar caracter?sticas desejadas. Os tecidos h?bridos aplicados em comp?sitos fibrosos, se projetados adequadamente, possibilitam uma melhoria ainda maior no rendimento, j? que, diferentemente dos tecidos convencionais, os tecidos h?bridos combinam fibras diferentes com alinhamento dependente do tipo de solicita??o de carga, podendo obter um material mais eficiente. Neste trabalho, foram realizadas an?lises com o intuito de estudar o comportamento de uma l?mina de comp?sito refor?ado por tecido h?brido bidirecional vidro/carbono em presen?a de descontinuidades geom?tricas. Para a realiza??o desse estudo o comp?sito foi fabricado a partir do processo de moldagem manual (hand-lay up). A partir dos ensaios realizados, de acordo com as normas da ASTM, obtiveram-se as caracter?sticas e propriedades do material (Percentual m?ssico e volum?trico de fibras, gr?ficos de tens?o x deforma??o, resist?ncia ?ltima e m?dulo de elasticidade). Foram analisadas configura??es com as fibras alinhadas nas dire??es principais (0? e 90?) e em ?ngulo (30?, 45? e 60?). A l?mina obteve um percentual m?ssico total de fibras de 38,98%, sendo 19,49% de fibra de vidro e 19,49% de fibra de carbono. J? para o percentual volum?trico obtiveram-se os seguintes resultados: 10,91% de fibra de vidro e 14,88% de fibra de carbono. A partir dos resultados obtidos nos ensaios de tra??o p?de-se observar que os materiais com fibras em ?ngulo apresentam resist?ncia inferior aos com alinhamento na dire??o principal e ao mesmo tempo apresentaram maiores alongamentos. A resist?ncia residual apresentou resultados semelhantes tendo valores em torno de 0,774, exceto para o material com angula??o de 30?, o qual apresentou um valor de 0,676. Diante dos resultados encontrados, torna-se evidente que a descontinuidade geom?trica ? um fator relevante na resist?ncia deste comp?sito e deve ser considerada.
The technological and economic development growing converge to the necessity of create increasingly efficient materials, which seek to combine high performance and low cost. The composites appear as solution to substitute conventional materials, because they are developed for specific applications and may have desired characteristics. Hybrid fabrics applied to fibrous composites, if adequately designed, allow an even greater improvement in efficiency, since, unlike conventional fabrics, these combine different fibers with different load-dependent alignment and can obtain a more efficient material. In this work, analyzes were carried out with the aim of studying the behavior of a composite lamina reinforced by bi - directional (glass/carbon) hybrid fabric in presence of geometric discontinuities. In order to carry out this study, the composite material was fabricated from the manual molding process (hand-lay up). From the tests performed, according to ASTM standards, the characteristics and properties of the material were obtained (mass and volume percentages of fibers, stressstrain curve, ultimate strength and modulus of elasticity). Configurations were made with fibers aligned in the main directions (0? and 90?) and at angles (30?, 45? and 60?). The composite lamina had a total mass percentage of fibers of 38.98%, being 19.49% of glass fiber and 19.49% of carbon fiber. For the volumetric percentage, the following results were obtained: 10.91% of glass fiber and 14.88% of carbon fiber. From the results obtained in the stress tests it was noted that the materials with angled fibers have lower resistance than those with alignment in the main direction and at the same time they presented greater stretches. The residual strength presented similar results having values around 0.774, except for the material with 30? angulations', which presented a value of 0.676. Considering the found results, it is evident that the geometric discontinuity is a relevant factor in the strength of this composite and should be considered.

A Drenagem Ácida de Mina (DAM) é um dos mais graves problemas ambientais decorrentes da extração mineral, porque se não for tratada de forma correta afeta a qualidade das águas subterrâneas e superficiais, o solo e, consequentemente, a saúde humana. Esta água residuária é formada pela oxidação de minerais sulfetados quando expostos a intempéries, como água e oxigênio, gerando, assim, ácido que com as chuvas são carregados lixiviando os elementos presentes no minério e desta forma, caracteriza-se por sua baixa concentração de matéria orgânica e baixo valor de pH, alta condutividade, altas concentrações de sulfato e de metais pesados. Convencionalmente, na indústria. essa água residuária é tratada pela processo de neutralização usando óxidos de cálcio, porém uma alternativa a este processo é o tratamento biológico da DAM em reatores anaeróbios contendo bactérias redutoras de sulfato (BRS), que reduzem o sulfato a sulfeto consumindo íons (H+) neste processo. Consequentemente, há um aumento do pH final e este sulfeto reage com os metais presentes em solução, precipitando na forma de sulfetos metálicos. Todavia, além de saber como se procede o tratamento desta água residuária nos reatores anaeróbios, é importante o desenvolvimento de modelos matemáticos a partir dos dados para se compreender com detalhes o processo como um todo, visto que os modelos nos permitem ver claramente a influência de uma variável sobre as demais. Diante disto, o objetivo principal deste trabalho foi avaliar a aplicação de modelos matemáticos aos dados experimentais do tratamento anaeróbio da DAM de um reator em batelada em escala de bancada, previamente operado. Propôs-se o modelo de Malthus-Monod-Fick para verificar quais grupos de micro-organismos estavam atuando no sistema e também avaliar o efeito da transferência de massa interna no grânulo sobre a ordem global da reação. E para isto especificamente, foram exploradas ferramentas de inferência estatística pouco usadas nesta área de modelagem de reator, tais como o Método da Máxima Verossimilhança e o teste de hipótese Chi-quadrado, buscando, portanto, obter o máximo de informações do experimento por meio do modelo desenvolvido. O modelo proposto foi implantado em linguagem de programação usando C++ com a biblioteca Root, usada principalmente para processar grandes volumes de dados e realizar análises estatísticas, partindo da premissa mais simples que avalia a atuação de apenas um grupo bacteriano atuando no sistema até a mais complexa que leva em consideração restrição da difusão de substrato no grânulo. Concluiu-se neste trabalho que mais de um grupo bacteriano atuaram no sistema: as BRS e as bactérias fermentativas (neste grupo inclui todos os tipos de micro-organismos que competem com as BRS pelo doador de elétrons, etanol), que com o passar do tempo a comunidade microbiana tornou-se mais selecionada devido as condições operacionais do reator escolhidas para favorecer as BRS e que em decorrência desta seleção houve o crescimento do biofilme que atuou como uma restrição a transferência de massa interna. Finalmente, provou-se matematicamente, com validação estatística do modelo, que esta restrição a difusão de massa no grânulo com o passar do tempo era a responsável por um comportamento global de primeira ordem mesmo usando valores dos coeficientes de Monod (KS e KA) muito pequenos, típicos de uma cinética de ordem zero, no qual a velocidade de consumo de substrato é independente da concentração do mesmo.
The acid mine drainage (AMD) is one of the most serious environmental problems in mining industry, because it affects the quality of groundwater and surface water, soil and, consequently, human health. This wastewater is formed by the oxidation of sulphide minerals when exposed to weathering, such as water and oxygen, thus causing acid that with the rain is loaded leaching the elements present in the area. This wastewater is characterized by its low concentration of organic material and low pH, high conductivity, high concentrations of sulphate and heavy metals. Conventionally in industry, the AMD is treated by the process of neutralization using calcium oxides, but an alternative to this process is the anaerobic treatment of the AMD in anaerobic reactors containing sulfate reducing bacteria (SRB), which reduce sulfate to sulfide consuming ions (H+), consequently there is an increased of the pH effluent and this sulfide reacts with the metals present in solution, precipitating in the form of metal sulfides. However, in addition to know how to proceed the treatment of wastewater in anaerobic reactors it is important to realize the modeling of data to understand in detail all the process, since the model allows us to clearly see the influence of one variable on the others. So, the main objective of this study was to model the experimental data from anaerobic treatment of the AMD in a batch reactor in bench scale, previously operated. It was proposed the model of Malthus-Monod-Fick to determine which groups of microorganisms were active in the system and also to evaluate whether there was any effect of internal mass transfer in the granule over the overall order of the reaction. And for this specifically, it was explored statistical tools little used in reactor modeling area, such as Maximum Likelihood Method and the Chi-square test of hypothesis, looking for this way to obtain the maximum information through the developed model. The proposed model was implemented in programming language using C ++ with the Root library, used mainly to process large volumes of data and perform statistical analysis, based on the simple premise that evaluates the performance of only one bacterial group working in the system to the most complex premise that takes into account restriction of substrate diffusion inside the granule. It was concluded in this study that more than one bacterial group acted in the system, the SRB and the fermentative bacteria (this group includes all kinds of microorganisms that compete with SRB by electron donor, ethanol), that a long the time the microbial community became more selected because the reactor operating conditions chosed to favor SRB and due to this selection was the growth of a biofilm which acted as a restriction to intern mass transfer. Finally, it has been proven mathematically, with statistical validation model, this mass diffusion restriction over time was responsible for a overall behavior of the first order even using values Monod coefficients small (KS e KA), typical a zero-order kinetics, in which the substrate consumption rate is independent of the concentration of this same substrate.
Fundação de Amparo à Pesquisa do Estado de Minas Gerais - FAPEMIG

L'ecoulement d'un film mince visqueux le long d'un plan incline est un prototype d'ecoulement ouvert avec surface libre, caracterise par la presence d'ondes solitaires et d'une suite bien definie d'instabilites secondaires conduisant au chaos spatio-temporel. L'objectif de cette these est de developper des modeles mathematiques permettant une description a la fois qualitative et quantitative des instabilites secondaires tridimensionnelles du film. La demarche suivie combine une methode aux residus ponderes dans la direction normale au film a un developpement en gradients, ceci afin d'eliminer les degres de liberte esclaves de l'epaisseur h du film. Un premier modele, obtenu en utilisant les profils de vitesse asymptotiques au voisinage du seuil et une methode de moyennage et de collocations aux frontieres, est presente en annexe (ch. 10). Une demarche plus systematique est exposee ici et conduit au premier ordre a un systeme de deux equations couplees decrivant l'evolution de l'epaisseur h et du debit local q. Au second ordre le modele ainsi ecrit implique quatre equations. Cependant un modele au second ordre simplifie a deux champs (4. 65-4. 66) est obtenu en appliquant une methode de galerkin. A l'aide de la theorie des systemes dynamiques, la recherche des ondes stationnaires bidimensionnelles dans leur referentiel en mouvement met en evidence le role joue par la dispersion d'origine visqueuse quant a la possibilite de chaos homocline, a la forme des ondes solitaires et a la selection des familles d'ondes stationnaires. L'analyse de floquet des solutions de (4. 65-4. 66) reproduit les resultats theoriques anterieurs sans toutefois expliquer les observations experimentales. Enfin, les simulations numeriques du developpement spatial des solutions de (4. 65-4. 66) avec forcage periodique ou aleatoire se comparent tres favorablement a l'experience et a la simulation numerique directe.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A escassez qualitativa e quantitativa de água associada aos impactos ambientais impostos por águas residuárias tem agravado o cenário da situação ambiental brasileira. Um setor que merece destaque é o de mineração de urânio visto que o Brasil é a sexta maior reserva mundial deste elemento e existe grande quantidade de rejeitos acumulados contendo íons metálicos, semimetálicos e radiotóxicos. A biossorção tem se mostrado eficiente no tratamento das águas residuárias com íons que mesmo em baixas concentrações são tóxicos. O objetivo deste trabalho foi avaliar a redução da concentração de urânio em soluções e em amostras de águas de drenagem ácida de minas da mina Osamu Utsumi das Indústrias Nucleares do Brasil por meio da biossorção. As biomassas escolhidas para uso como biosorvente foram cascas de banana, sementes de moringa e borra de café. Ensaios de decomposição térmica, porosimetria de adsorção de nitrogênio e microscopia eletrônica de varredura foram efetuados de modo a caracterizar fisicamente os biosorventes. As variáveis analisadas para os ensaios em batelada como tamanho e massa do biosorvente, temperatura do ensaio, tempo de contato, pH e concentração inicial da solução de urânio foram definidas com o planejamento fatorial de experimentos. A partir dos ensaios em batelada realizados, pôde-se observar que as biomassas com maior área superficial e menor volume de poros resultaram em maiores valores de eficiência de remoção, sendo a ordem crescente destes parâmetros: cascas de banana < borra de café < sementes de moringa. Dentre os biosorventes estudados as sementes de moringa apresentaram os maiores valores de eficiência de remoção, seguida pela borra de café e cascas de banana. Em soluções de 100 mg L-1 as eficiências de remoção das sementes de moringa e cascas de banana foram iguais a 0,7429 e 0,2483, respectivamente; em valores de concentração de 25 mg L-1 as borras de café apresentaram eficiência de remoção igual a 0,9358. Em amostras de efluente com concentrações de urânio na ordem de 5 mg L-1 , as sementes de moringa apresentaram-se como o biosorvente com melhor eficiência de remoção (~0,8) quando comparadas as cascas de banana (~0,5) e borra de café (~0,7).
The qualitative and quantitative water scarcity associated with environmental impacts posed by wastewater has worsened the brazilian environmental scenario. Uranium mining is a prominent sector in Brazil context, since this country owns the sixth biggest uranium reserve in the world and there is large amount of accumulated tailings containing metallic, semi-metallic and radiotoxic ions. In general, biosorption has shown significant efficiency on effluent treatment, removing ions which even in low concentrations present toxicity. This work aimed to reduce the concentration of uranium by using biosorption in both cases, lab scale solutions and acid mining drainage effluent samples from Osamu Utsumi mine, wich belongs to Usinas Nucleares do Brasil. The selected biomasses used as biosorvent were banana peels, moringa’s seeds and coffee waste. Thermal decomposition, nitrogen adsorption porosimetry and scanning electron microscopy were performed for physical characterization. The studied variables for the batch tests as size and mass of biosorvent, temperature of tests, contact time, pH and initial concentration of solutions of uranium were defined by using design of experiments. From the tests carried out it was observed that the biomasses with a higher surface area and smaller pore volume resulted in higher removal efficiency values, with an ascending order of these parameters: banana peels