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Influência do antigo lixão do Roger, João Pessoa, nas águas subterrâneas locaisFagundes, Giulliano de Souza 30 March 2010 (has links)
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Previous issue date: 2010-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study had the aim of evaluating the groundwater quality nearby the decommissioned Roger
open dump in João Pessoa, Brazil, which was decommissioned in 2003 and occupies an area of
17 hectares, adjacent to the mangrove besides Sanhauá river, which increases the impact
produced from the inadequate disposal of solid wastes. During the last three years of operation
the open dump also received the solid wastes from the cities of Bayeux and Cabedelo. The
monitoring of groundwater quality was done through six wells called P1, P2, P3, P4, P5 and P6,
spread over the internal, direct influence and indirect influence areas of the decommissioned
open dump. P1, P2, P3 and P4 were particular wells that the owner allowed to be included in the
monitoring, while P5 and P6 were constructed in the internal area of the former open dump.
Sampling occurred every three or four months during almost three years. The following
parameters were monitored: pH, conductivity, hardness, color, turbidity, dissolved total solids,
BOD, COD, oil and grease, chloride, ammonia, nitrite, nitrate, aluminum, plumb and
thermotolerant coliform. For statistical treatment of collected data, analysis of variance through
the GT-2 grafic method was employed. Results have shown that P5 and P6 presented the worst
water quality indicators suggesting that the former open dump poses some influence on the local
groundwater quality. However, oil and grease, thermotolerant coliform and chloride were found
in all the wells, indicating that other sources of contamination are present in the site. The
groundwater in the region of the decommissioned Roger open dump does not satisfy the
standards for drinking water according to Brazilian legislation. / Este trabalho objetivou avaliar a qualidade das águas subterrâneas na área da influência do
antigo lixão do Roger em João Pessoa. Desativado em 2003, o antigo lixão ocupa uma área de
manguezal, com 17 hectares, adjacente ao estuário do Rio Sanhauá, próximo ao centro de João
Pessoa, potencializando os problemas ambientais e de saúde pública decorrentes da disposição
inadequada de resíduos. Nos últimos anos de funcionamento, o referido lixão também recebeu
os resíduos sólidos de cidades vizinhas (Cabedelo e Bayeux). O monitoramento das águas
subterrâneas foi realizado através de seis poços denominados P1, P2, P3, P4, P5 e P6,
distribuídos entre a área interna do referido lixão (P5 e P6), a área de influência direta (P1 e P4)
e a indireta (P2 e P3). Os poços P5 e P6 foram construídos para a pesquisa, enquanto que os
outros são de particulares que permitiram o acesso. O P5 é considerado o poço de montante e o
P6 de jusante em relação à massa de resíduos sólidos e o fluxo predominante das águas
subterrâneas. As águas coletadas foram caracterizadas durante 3 anos com freqüência trimestral
ou quadrimestral, através dos seguintes parâmetros: pH, condutividade, dureza, cor, turbidez,
sólidos totais dissolvidos, DBO, DQO, óleos e graxas, cloretos, amônia, nitrito, nitrato,
alumínio, chumbo, e coliformes termotolerantes. Para tratamento dos dados foi aplicada análise
de variância, através do método gráfico GT-2 que permitiu a comparação gráfica dos parâmetros
entre os poços, além da análise gráfica do comportamento temporal de cada parâmetro e
também com Valores Máximos Permitidos (VMP) estabelecidos pela Portaria nº 518 do
Ministério da Saúde e a Resolução do Conselho Nacional de Meio Ambiente (CONAMA) nº
396 de 2008. O monitoramento das águas subterrâneas demonstrou que os poços P5 e P6
apresentaram os piores indicadores de qualidade tanto em comparação a legislação quanto aos
demais poços. No entanto, em todos os poços foi constatada a presença de óleos e graxas,
coliformes termotolerantes e cloretos, indicando haver outras fontes de contaminação . As águas
subterrâneas nas proximidades do antigo lixão do Roger não atendem ao padrão de potabilidade
da legislação. Mesmo após a desativação o lixão ainda é uma fonte de contaminação e oferece
riscos a saúde da população circunvizinha, além de comprometer os usos futuros que se
poderiam fazer das águas subterrâneas.
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Water Courses in Kvarntorp : An Evaluation of Water Chemistry from Monitoring Data 1994-2012Karlsson, Lovisa January 2014 (has links)
The Kvarntorp area, some 200 km SW of Stockholm, Sweden, is a former mining site for alum shale. Kvarntorpshögen is a refuse dump from the hydrocarbon extraction during 1940-1965. The area is also dotted by abandoned quarries, which most are water filled today. The area is divided into two watersheds; the central and the eastern. Frommestabäcken is the main watercourse flowing out of the central watershed while Frogestabäcken is the corresponding watercourse in the eastern watershed. These two watercourses have been sampled annually since 1994 by consulting companies for the municipality of Kumla. The sampling sites at Ulftorpsbäcken (main inlet to the central watershed) and at the outlet from Serpentindammssystemet (the water treatment system in the central watershed) was added to the sampling program in 1997 and 1996 respectively. Other consulting companies have sampled the groundwater around Kvarntorpshögen (in 2004) and the water in the lake Norrtorpssjön (in 2004), which is an old water filled quarry. The lake Norrtorpssjön has also been sampled as part of a project performed by Örebro University. This thesis is a compilation and evaluation of all this data but the main part will be given focused on seasonal variations. Samples have been analysed with regard to the metals Na, K, Ca, Mg, Fe, Al, Li, B, As, Cu, Ni, Zn, Co, Cr, Cd, Pb, Mo, Sr and U. Other analysed parameters were tot-N, tot-P, bicarbonate (alkalinity), sulphate, chloride and the parameters pH, electrical conductivity and COD(Mn). Samples of bottom fauna have also been collected in Frommestabäcken. Concentration of most metals increased in the surface water while passing the Kvarntorp area. High metal concentrations were found for example in some of the groundwater samples. Such high concentrations were not observed in the samples from Frommestabäcken or Frogestabäcken, indicating for example dilution of metals or immobilisation through precipitation or adsorption. Seasonal effects on the dissolution and precipitation/adsorption of compounds were observed at all annually sampled watercourses. One of these effects was the spring- and autumn circulation of the lake Norrtorpssjön. The lake forms a thermocline during summer which causes higher concentrations of metals beneath the thermocline. During circulation these concentrations mixes throughout the depth profile which affects the amount of elements that is transported from the lake via Frogestabäcken. During winter the highest concentrations of metals are expected near the surface of the lake since the surface is colder than the rest of the water mass.
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Development of a conceptual model for ash dump system using hydraulic and tracer test techniquesOctober, Adolf Gerswin January 2011 (has links)
Magister Scientiae - MSc / Coal provides for 77% of South Africa’s primary energy needs and is therefore a major resource that supports the socio-economic needs of South African citizens. Power stations are the major consumers of coal in South Africa and produces electricity from burned coal. The burning of coal produces a large volume of ash that is disposed in the form of ash dump systems. The ash dump system is treated with high salinity process water from the power station for dust suppression. The process water contains salts due to evaporation processes from the recirculation of water in the cooling water system. Various studies to evaluate the sustainability of the ash dump system as a sustainable salt sink were therefore conducted. This study aimed to develop a conceptual model for the ash dump system by evaluating the movement of the process water trough the ash dump and the impacts it might have on the underlying weathered dolerite aquifer. This was achieved by evaluating the hydraulic and transport properties of the ash dump system. An initial site conceptual model was first established prior to the application of the hydraulic and transport methods. The initial conceptual model was based on the literature, previous reports and an initial site walk over. Known and tested hydraulic and transport methods were applied n bo.th field and laboratory scale for the saturated part of the ash dump system. The laboratory experiments comprised of column and core experiments. These methods assisted in parameter estimation of hydraulic and transport properties and also assisted in the planning of the field experiments. The field experiments were conducted in the form of slug tests, tracer dilution and natural gradient divergent tracer test experiments. The combined laboratory and field experiments provided statistically significant values that were then used as inputs into the conceptual model. Field experiments were also applied to a surrogate aquifer that represented the underlying shallow weathered dolerite aquifer of the ash dump system. The components of the updated conceptual model identified and investigated include the physical environment, the calculated hydraulic and transport properties.The ash dump can be conceptualized as a 20 to 30 meter high heap of consolidated clay size ash particles built on top of an underlying shallow weathered dolerite aquifer. The ash dup is directly connected to the underlying weathered dolerite aquifer. The saline water within the saturated zone has the ability to move through the ash dump system with hydraulic conductivities ranging between 10-1-10- 2 m/day, with flow velocities of 7-8m/day and effective porosities of 1%-2%. The hydraulic properties of the ash dump are, amongst others, controlled by the ash geology, contact time of the process water with the sh and show a significant reduction in hydraulic conductivity over time, before reaching a steady state. The transport properties are controlled by advection and spreading in available pathways. Results for the surrogate underlying fractured rock aquifer show flow velocities of 31m/day and an effective porosity of 1%.This suggests that the underlying weathered dolerite aquifer is vulnerable to process water contamination from the ash dump system. The study illustrates the importance of a site conceptual model before the application of investigative methods. Hence having a site conceptual model provides an excellent platform for hydraulic and transport estimation. The development of a site conceptual model enhanced the understanding of flow and transport movement of the processed water trough the ash dump, it also assisted as a beneficial tool to enhance ash dump management. / South Africa
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Modernizace systému nakládání s odpady / Modernization of the waste management systemŠofr, Jan January 2013 (has links)
The aim of this thesis is to suggest the right solution for the current situation of a disposal dump located close to the town of Lány in Middle Bohemia. There are two possible solutions how to continue with the project, either leaving the current state of the disposal dump or building an integrated centre for mechanical -- biological treatment of the waste. Taking into account economical calculations and other factors like time factor, investment amount, expected year profit, payback period, changes in european legislation and others, I have deciced to suggest one more solution. In my opinion the most efficient way for solving the situation is using financial support from Operational Programme Environment in a field Waste Management Improvement and buy composting and sorting line .
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Introducción de un LHD híbrido a la industria minera y sus posibilidades en el mercado chilenoRojas Lafuente, Gonzalo Esteban January 2017 (has links)
Ingeniero Civil de Minas / El presente estudio busca determinar las posibilidades de mercado del nuevo LHD híbrido diésel eléctrico, 18HD, en la industria minera en Chile. Para establecer las posibilidades primero se compara la tecnología híbrida con las tecnologías presentes hasta ahora en la industria y posteriormente se hace un análisis de mercado de los equipos subterráneos en Chile. La industria minera en general, y particularmente en Chile, ha estado dominada por los equipos con accionamiento mediante Diésel, mientras que la participación de los equipos eléctricos ha estado bastante restringida debido a sus limitaciones operacionales. La principal desventaja de los equipos diésel es la alta emisión de material particulado y contaminante. Esta desventaja sumada a los nuevos desafíos de la minería que buscan aumentar la productividad, confiabilidad y mantenibilidad han impulsado a las empresas proveedoras de equipos a desarrollar de nuevas tecnologías que permitan entregar soluciones acordes a los desafíos de la actualidad. Un ejemplo de esto es el equipo híbrido desarrollado por Joy Global, el cual tiene un sistema de accionamiento diésel eléctrico. Entre los principales beneficios de este equipo destacan: recuperación de energía de frenado, mayor aceleración, menores costos de mantenimiento, menor uso de combustible y requerimientos de mantención, aumento de la disponibilidad mecánica, entre otros. Este equipo ha completado su etapa de prototipo y se someterá a una prueba industrial en una operación en Chile para cuantificar todos los posibles beneficios que entrega. El mercado de los equipos en Chile está principalmente dominado por grandes proveedores mundiales de la minería subterránea como los son Atlas Copco, Sandvik y Caterpillar. Los clientes se dividen en dos grandes grupos; la gran minería, principalmente aquellas minas explotadas por block caving, las cuales tienen un gran poder de negociación al momento de comprar equipos; y la mediana minería, la cual se ha visto afectada en mayor parte por la situación del mercado. Para que el equipo pueda ser comercializado con éxito debe aprovechar las oportunidades que ofrece el mercado, las cuales son; el envejecimiento de la flota de equipos en Chile, la construcción de grandes proyectos y la recuperación del precio. Además, debe destacar por sobre la competencia en cuanto a los servicios entregados.
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Berechnung des Strahlungsuntergrundes in der Umgebung der Strahlfänger an der Strahlungsquelle ELBENaumann, Bärbel January 2002 (has links)
Beam dumps are installed at the experimental areas of the ELBE facility. Their purpose is to absorb the primary electron beam and the secondary radiation. The beam dump consists of a purified graphite core inside a water cooled stainless steel vessel. The radiation shield surrounding the beam dump will be designed individually for each experimental area. In this context, dose rate calculations were carried out to estimate the dose rate source term around the stainless steel vessel of the beam dump. Detailed Monte Carlo simulations were carried out using the code FLUKA. The energy dependent photon and neutron fluences and the equivalent dose rates were obtained near the surface of the cylindrical steel vessel for a beam current of 1 mA and energies of 20 MeV and 50 MeV.
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Design of Miniature Three-Phase Dump Load ModelSalisbury, Tiffany, Akram, Muhammad Arsal January 2022 (has links)
In hydropower plants, a local load, also known as a dump load, could be installed to balance theelectrical grid by consuming excessive power. This enhances the dam safety. A design for asmall-scaled three-phase dump load is presented in this thesis. The designed model is built andevaluated through simulations and experiments. The results show that the system is purelyresistive. The per phase resistance of the model can be calculated with geometrical analysis ofthe design.
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LHD operations in sublevel caving mines: a productivity perspectiveTariq, Muhammad January 1900 (has links)
Mining is a high-risk industry, so efficiency and safety are key priorities. As mines continue to go deeper and exploit low-grade deposits, bulk mining methods, such as sublevel caving (SLC), have become increasingly important. SLC is suitable for massive steeply dipping ore bodies and is known for its high degree of mechanisation, productivity, and low operational cost. Moreover, technological developments and mechanisation have allowed these methods to be applied at greater depths. In modern mechanised mines Load haul dump (LHD) machines are central to achieving the desired productivity. Therefore, automation of LHDs and their increasing use in mines make it crucial to understand the performance of these machines in actual mining environments. The aim of this research was to understand the differences in the productivity of semiautonomous and manual LHDs and identify how external factors impact the performance of these machines in SLC operations. The research also investigated how LHD operator training could improve the loading efficiency. Performance data for semi-autonomous and manual LHDs were collected from LKAB’s Kiirunavaara mine’s central database, GIRON. These data were used to compare cycle times and payloads of semi-autonomous and manual LHDs. The data were filtered and sorted so that only data where both machine types were operating in the same area (crosscut, ring, and ore pass) were used. To understand the impact of external factors, data on the occurrence of boulders were collected from LKAB’s Malmberget mine by recording videos of LHD buckets, while the data on operator training were obtained by performing baseline mapping and conducting a questionnaire study with the LHD operators at LKAB’s Kiirunavaara mine. The results of the comparative analysis of manual and semi-autonomous LHDs showed the mean payload was 0.34 tonnes higher for manual LHD machines. However, the differences were not consistent across different areas of the mine. Similarly, when comparing the cycle times, in 57% of the studied area, manual LHDs had lower cycle time, while the opposite was true in the remaining 43% of the areas. Therefore, the differences in cycle time and payload due to mode of operation are not conclusive, meaning that one machine type does not completely outperform the other. This highlights the importance of understanding the external factors that cause such differences. Moreover, the findings emphasize the need to upgrade LHD operator training based on pedagogical principles and the inclusion of new technologies to enhance loading efficiency and increase overall productivity.
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Effects of Input Power Factor Correction on Variable Speed Drive SystemsLee, Shiyoung 08 April 1999 (has links)
The use of variable speed drive (VSD) systems in the appliance industry is growing due to emerging high volume of fractional horsepower VSD applications. Almost all of the appliance VSDs have no input power factor correction (PFC) circuits. This results in harmonic pollution of the utility supply which could be avoided.
The impact of the PFC circuit in the overall drive system efficiency, harmonic content, magnitude of the system input current and input power factor is particularly addressed in this dissertation along with the development of analytical methods applicable to the steady-state analysis of input power factor corrected VSD systems.
Three different types of motors - the switched reluctance motor (SRM), permanent magnet brushless dc motor (PMBDC) and dc motor (DCM) are employed in this study. The C-dump converter topology, a single switch per phase converter, is adopted for the prototype SRM- and PMBDC-based VSD systems. The conventional full-bridge converter is used for DCM-based VSD systems. Four-quadrant controllers, utilizing PI speed and current control loops for the PMBDC- and DCM-based VSD system, are developed and their design results are verified with experiment and simulation. A single-quadrant controller with a PI speed feedback loop is employed for the SRM-based VSD system.
The analysis of each type of VSD system includes development of loss models and establishment of proper operational modes. The magnitude of the input current harmonic spectra is measured and compared with and without a front-end PFC converter. One electromagnetic compatibility (EMC) standard, IEC 1000-3-2 which describes the limitation on harmonic current emission is modified for 120V ac system. This modified standard is utilized as the reference to evaluate the measured input current harmonics. The magnitude of input current harmonics for a VSD system are greatly reduced with PFC preregulators. While the input PFC circuit draws a near sinusoidal current from an ac source, it lowers the overall VSD system efficiency and increases cost of the overall system. / Ph. D.
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Hydro- und geochemische Prozesse in oberflächennahen Kippensedimenten des Braunkohlentagebaus ZwenkauWiegand, Ute 28 November 2004 (has links) (PDF)
Die vorliegende Arbeit wurde im Rahmen des BMBF-geförderten Projektes "Luft- und bodengestützte spektrometrische Untersuchungen zur Differenzierung reaktiv veränderter Braunkohlentagebaugebiete in Mitteldeutschland" (Vorhaben 02 WB 9667/5) als Kooperation zwischen dem GeoForschungsZentrum Potsdam (GFZ), dem Deutschen Zentrum für Luft- und Raumfahrt (DLR), der Gesellschaft für Angewandte Fernerkundung (GAF) und dem Umweltforschungszentrum Leipzig/Halle GmbH (UFZ) angefertigt. Grundidee des Projektes war es, die durch spektrometrische Erfassungsmethoden der Fernerkundung erhaltenen Überfliegungsdaten mittels konventioneller petrographischer, mineralogischer und geochemischer Analytik zu kalibrieren. Der Schwerpunkt dieser Arbeit lag dabei in der Charakterisierung der hydro- und geochemischen Veränderungen in den Kippensedimenten des im mitteldeutschen Raum südlich von Leipzig aufgeschlossenen Braunkohlentagebaus Zwenkau. Zu diesem Zweck wurden die Kippensedimente in Abhängigkeit des Schüttungsalters und der Lagerung untersucht sowie die spezifischen Merkmale der Kippenwässer und Bodengase erfaßt, um die im Kippenkörper ablaufenden chemischen, petrographischen und gefügemäßigen Veränderungen sowie die Wechselwirkungen zwischen den Sedimenten, Wässern und Bodengasen zu beschreiben. Schließlich wird ein Modell zur zeitlichen Entwicklung der Abraumförderbrückenkippe, beginnend bei ihrer Verkippung bis hin zu einem Alter von etwa 20 Jahren, vorgestellt, welches die beobachteten Erscheinungen bezüglich der auftretenden endogenen und exogenen Wechselwirkungsfaktoren gut erklärt. / This thesis was prepared in cooperation with the GeoForschungsZentrum Potsdam (GFZ), the Deutsches Zentrum für Luft- und Raumfahrt (DLR), the Gesellschaft für Angewandte Fernerkundung (GAF), and the Umweltforschungszentrum Leipzig/Halle (UFZ) in frame of the project "Airborne and laboratory spectroscopic studies for differentiation of reactively alterated lignite mining pits in Central Germany" (No. 02 WB 9667/5) which was gratefully supported by the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF). The major idea of the project was to achieve a calibration of the spectroscopic data acquired by the remote sensing though the results obtained from conventionally petrographical, mineralogical and geochemical analyses. The main goal of this thesis was the characterization of the hydro- and geochemical alterations in the conveyor bridge dump of the open lignite mining pit Zwenkau which is located in the Central Germany District southern of Leipzig. Therefore, dependent on their ages in terms of dumping and their surface-near locations the dump sediments were investigated and the specific properties of the different types of dump water and soil gases were acquired as well in order to describe the ongoing chemical, petrographical and structural alterations and interactions between the sediments, the water and the soil gases in the conveyor bridge. Finally, a model of the chronological development of the overburden sediments starting from their spilling up to an age of about 20 years is proposed which well explains the observed phenomena regarding the appearing endogenous and exogenous interaction factors.
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