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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Probing the Toba super-eruption: Insights from oxygen isotope geochemistry and geobarometry

Budd, David January 2011 (has links)
The Toba caldera located in north Sumatra, Indonesia, is the source of the largest volcanic eruption in the Quaternary (Rose & Chesner 1987). Its enormous volume of 2800 km3 has been a matter of debate for decades and it is still unclear where and how the Toba magma was assembled. This study documents oxygen isotope data for a suite of whole rocks and minerals erupted as part of the Young Toba Tuff (YTT), some 74 ka ago (cf. Chesner et al. 1991). Oxygen isotope data has been obtained in-situ from quartz crystals (SIMS), whole rocks (conventional), as well as quartz, feldspar, amphibole and biotite (laser fluorination). In combination with cathodoluminescence (CL) imaging on the quartzes, the data are used to test the relative roles of shallow magmatic processes such as crystal fractionation, magma-crust interaction and crystal recycling within the Toba magmatic system. In addition, thermobarometric calculations have been performed on plagioclase and amphibole phenocrysts from the YTT to help unravel the magma storage and plumbing system that gave rise to the YTT. The combined evidence will be used to derive a model for shallow magma evolution and storage at Toba some 74 ka ago. The CL images of quartz crystals exhibit defined patterns of magmatic zoning, which broadly coincide with fluctuations in δ18O values in the quartz crystals, allowing correlation of textural and compositional data. Measured δ18Oquartz values range from 6.7 ‰ to 9.4 ‰, independent of position on crystal core or rim. Values for δ18Omagma have been calculated from quartz phenocrysts (assuming Δquartz-magma is 0.7 ‰ at magmatic temperatures). The lowest magma value is 6.0 ‰, apparently reflecting a primitive isotopic signal (Taylor & Sheppard 1986). The maximum calculated magma value is 8.7 ‰, indicating a significant crustal component and thus multiple sources to the Toba magmatic system. Several crystals, however, show internal zoning with gradually lower values towards the rims, pointing to a late-stage low-δ18O input, most probably from the shallow volcanic edifice. The crystals therefore record a complex and heterogeneous origin of the YTT magma, comprising a primitive and an evolved magmatic component topped up with several substantial crustal contributions to finally assemble the massive volume of the 74 ka Toba eruption.
22

COMMERCIAL BUILDING WATER QUALITY: DETECTING CHEMICAL AND MICROBIAL CHANGES, THEIR CAUSES, AND EVALUATING REMEDIAL ACTIONS

Elizabeth Sarah Montagnino (10723932) 29 April 2021 (has links)
<p>In the U.S, more than 5.6 million commercial buildings are in operation and some include offices, schools, and childcare centers. These large buildings have complex indoor plumbing and often drinking water chemical and microbiological safety hazards can go undocumented. Generally, the larger the building’s square footage, the greater number of building occupants potentially exposed to the drinking water and greater amount and complexity of indoor cold and hot water piping and appurtenances. Because commercial buildings routinely undergo periods of low to no water use (e.g., holidays, weekends) cold and hot water can stagnate in the plumbing. This stagnation can allow for chemical and biological drinking water quality safety to deteriorate. This thesis work was designed to examine water safety challenges in school, childcare center, and office buildings to address existing knowledge-gaps.<br></p><p><br></p><p>The study described in Chapter 1 was conducted to better understand the risks of elevated copper levels at U.S. schools and childcare centers. Study goals were to: (1) understand occurrences of copper in school and childcare center drinking water systems, (2) review acute and chronic health impacts associated with the ingestion of copper contaminated water, and (3) examine the effectiveness of remedial actions to address copper in drinking water. Of the more than 130,000 schools and 856,000 childcare centers in the U.S., only about 1.7% of all those facilities had copper drinking water testing data recorded in a federal Safe Drinking Water database since the database was created in 1992. Of these facilities that were designated public water systems, about 13% (2,332) had reported a copper drinking water exceedance. Over a period of 30 years, very few studies have been conducted to document copper levels in schools and childcare centers. Available studies reported widely different sampling protocols and remedial actions. Flushing copper contaminated water from plumbing was the most evaluated remedial action, but flushing sometimes needed to be repeated indefinitely because copper exceeded safe limits within hours after flushing stopped. In-building water treatment with ion exchange systems and orthophosphate corrosion inhibitor addition have been used. At present, there is limited data from testing for copper in schools and childcare centers as well as studies to aid building managers in identifying and remediating copper occurrences. <br></p><p><br></p><p>The study described in Chapter 2 was designed to better understand chemical and microbiological quality in a green office building due to weekend stagnation events (~60 hours per event). Specific goals were (1) to investigate characterize disinfectant, pH, as well as heavy metal and microbial contaminant levels at the building point-of-entry and fixtures throughout the building, (2) understand how water quality varied spatially and by fixture use frequency, and (3) investigate the effectiveness of remedial actions on removing the water quality problems identified. As-built plumbing drawings were used to create a sampling plan and flushing plan. The total chlorine concentration decreased during stagnation (p < 0.05) and was highest at the building entry point (max 0.8 mg/L), and lower throughout the building (max 0.28 mg/L). Total cell counts were greater on Mondays compared to Fridays (p < 0.05). Legionella spp. was highest at the fixture with zero water use recorded during the study. Copper and lead levels throughout the building increase over the weekend (p < 0.05). Copper exceeded the U.S. federal health-based drinking water limit (1.3 mg/L) at 4 of the 12 tested locations. These locations all branched off the same riser. Manual fixture flushing temporarily reduced copper levels, but copper rebounded quickly prompting the need to flush fixtures every 19 hours. Results showed that drinking water testing should be required for building water systems before occupancy permits are issued, and after an extended stagnation period to understand worst case conditions. Testing should include disinfectant level, copper, lead, and legionella. <br></p><p><br></p><p>This thesis research found that a general lack of water testing data for existing office, school, and childcare center buildings inhibited a wider understanding of water safety risks. It is recommended that building officials adopt water testing as a requirement for building occupancy certificates. Testing should also be conducted periodically during the life of the buildings especially after unusually long stagnation periods (e.g., shutdowns or holiday breaks), and in buildings where children or other sensitive populations (e.g., elderly or people with underlying conditions) are occupants. Testing should include disinfectant level, copper, lead, and legionella at the point of entry and multiple locations throughout the building, depending on fixture use and building occupants. Without water testing, occupants may continue to be exposed to water that does not meet federal safe drinking water limits and go undetected. If contamination is found, building managers should review the flushing plan and potentially consider point of use water treatment to address short- and long-term water safety problems. <br></p>
23

Towards Optimization of Residual Disinfectant Application for Mutual Control of Opportunistic Pathogens and Antibiotic Resistance in In-Building Plumbing

Cullom, Abraham Charles 13 July 2023 (has links)
Opportunistic premise (i.e., building) plumbing pathogens (OPPPs) and antibiotic resistant bacteria are emerging microbial concerns in drinking water. OPPPs, such as Legionella pneumophila, are the leading cause of drinking water disease in many developed countries. Contributing factors include the relative success in controlling fecal pathogens, the presence of complex building plumbing systems that create habitats for OPPPs, and the relative resistance of OPPPs to disinfectants, and aging populations that are susceptible to infection. Concurrently, drinking water is increasingly being scrutinized as a potential environment that is conducive to horizontal gene transfer of antibiotic resistance genes (ARGs), selection pressure for enhanced survival of resistant bacteria, and a route of transmission of antibiotic resistant pathogens. While maintaining a disinfectant residual is an established approach to controlling OPPPs in premise plumbing, some studies have indicated that co-resistance and cross-resistance to disinfectants can increase the relative abundances of resistant bacteria and ARGs. Thus, there may be trade-offs to controlling both OPPPs and antibiotic resistance in premise plumbing that call for controlled study aimed at optimizing residual disinfection application for this purpose. A critical review of the scientific literature in Chapter 2 revealed that premise plumbing is a biologically and chemically complex environment, in which the choice of pipe material has cascading effects on water chemistry and the corresponding premise plumbing microbiome. This, in turn, has broad implications for the control of OPPPs, which need to be elucidated through controlled experiments in which worst case premise plumbing conditions are held constant (e.g., warm temperature), while other variables are manipulated. Chapter 3 introduces the convectively-mixed pipe reactors (CMPRs) as a novel low-cost, small footprint approach to replicably conduct such experiments. The CMPRs were demonstrated to effectively simulate key chemical and biological phenomena that occur in distal reaches of premise plumbing. In Chapter 4, the CMPRs were leveraged to study the interactive effects of four disinfectants (chlorine, monochloramine, chlorine dioxide, and copper-silver ionization) and three pipe materials (PVC copper, and iron). The CMPRs were inoculated with two antibiotic-resistant OPPPs: Pseudomonas aeruginosa and Acinetobacter baumannii. It was found that pipe-material (PVC or PVC combined with iron or copper) profoundly impacted the water chemistry in a manner that dictated disinfection efficacy. In Chapter 5, we applied shotgun metagenomic shotgun sequencing to evaluate effects of the combination of pipe material and disinfectant type on the wider microbial community, especially their ability to select for or reduce ARGs. In Chapter 6, we used CMPRs and metagenomic sequencing in a study comparing Dutch drinking water practices to our prior testing in an American system. Dutch drinking water is of interest because of lack of historical use of disinfectants was hypothesized to result in a microbial community that is relatively depleted of ARGs or mobile genetic elements, which can enhance spread of ARGs as disinfectants are applied. Generally, it was found that OPPPs required higher doses of disinfectants for inactivation than the general microbial community, sometimes concentrations approaching the regulatory limits in the US (e.g., 4 mg/L of total chlorine). Even successful reductions were modest, typically ~1-log, and failed to eliminate either P. aeruginosa or A. baumannii. Moreover P. aeruginosa, A. baumannii, and non-tuberculous mycobacteria varied substantially in their preference for pipe material and susceptibility to disinfectants. We found that disinfectants tended to increase the relative abundance of OPPPs, ARGs, and mobile genetic elements. Disinfectants were sometimes associated with net increases in levels of these pathogens and genes when applied at low levels (e.g., 0.1 mg/L of monochloramine), which effectively acted to reduce competition from less resistant and non-pathogenic taxa. When a low dose of monochloramine was applied to PVC CMPRs in the US, we estimated from metagenomic sequencing data that this water contained roughly 100,000 cells per milliliter of taxa known to contain pathogenic members. The Dutch drinking water exhibited more diverse microbial communities and lower relative abundances of taxa containing pathogens. ARGs were two times proportionally more abundant in CMPRs operated in the US without disinfectant than in the corresponding CMPRs operated in the Netherlands. The findings of this dissertation can help to optimize the application of in-building disinfectant addition for addressing concerns related both to OPPPs and antibiotic resistance. The studies herein highlight the necessity of developing comprehensive OPPP and antibiotic resistance control strategies that emphasize not just disinfectant dose, but other key control parameters such as contact time, hydraulics, and temperature. The functional diversity of OPPPs, antibiotic resistant bacteria, and the background premise plumbing microbiome further necessitates broad, holistic programs for monitoring and control. / Doctor of Philosophy / Efforts to provide safe drinking water face two emerging threats: the rise of pathogens that thrive in the plumbing environment that delivers water to the tap and the rise of antibiotic resistance. In the US and many other parts of the world, opportunistic pathogens are the predominant agents responsible for disease spread by tap water. Opportunistic pathogens tend to infect aged or immunocompromised individuals (hence, 'opportunistic') and grow well in in-building plumbing. Globally, antibiotic resistance is on the rise and becoming a fundamental threat to modern medicine. Pathogenic bacteria become resistant to antibiotics used to treat infections when they acquire antibiotic resistance genes (ARGs), which can happen either by mutation or from other resistant bacteria sharing ARGs. Overuse or misuse of antibiotics can impose selection pressure that stimulates horizontal gene transfer and enhance survival of bacteria that are resistant. Prior studies have suggested that under some circumstances, disinfectants used to control pathogens in drinking water can also select for antibiotic resistant bacteria. Thus, the overarching goal of this research was to optimize the type and dose of disinfectant used, depending on building-level factors such as pipe material, for effectively controlling proliferation of both opportunistic pathogens and antibiotic resistance. This dissertation largely focuses on in-building plumbing systems, which are home to potentially tens of thousands of bacterial cells per milliliter of water or per square centimeter of internal pipe surfaces. These bacteria interact not only with each other and other microbes, but also with features of the plumbing environment, such as the water chemistry or the pipe materials. Building plumbing systems are highly intricate ecosystems that can undermine the effectiveness of disinfectants provided by utilities. One major contribution of this research is the development of the convectively-mixed pipe reactors (CMPRs) as a simple and easy-to-use test system that recreates combinations of features of interest encountered in in-building plumbing. We applied the CMPRs to study two common residual disinfectants (chlorine and monochloramine) supplied by water utilities, and two other disinfectants (chlorine dioxide and copper-silver ionization) which are commonly dosed by building operators, especially in hospitals and other buildings housing individuals susceptible to infection. These four disinfectants were applied to CMPRs consisting of PVC, copper, and iron pipe. Chemical, culture, and DNA methods were used to understand how these disinfectants affected the microbes and their ecology. We then took the opportunity to set up CMPRs in the Netherlands, where there has been no historical exposure to chlorine because their water quality regulations emphasize limiting nutrients in the water and elevating the hot water line temperatures as means to control microbial growth. The CMPRs effectively produced worst-case plumbing scenarios, where opportunistic pathogens were especially difficult to control through residual disinfection. Dosed disinfectants tended to be no longer measurable in the water after five hours. The CMPRs also showed that the disinfectant most effective for one pathogen could be the least effective for another. If doses were applied near regulatory limits, the concentrations of pathogens and antibiotic resistance genes decreased. However, opportunistic pathogens tended to survive better than background populations of bacteria. Bacteria carrying ARGs also survived some disinfectant conditions better as well. Thus, if doses were applied at levels that could inactivate some microbes, but not the opportunistic pathogens, pathogen abundances sometimes increased. These results were largely confirmed in the experiment with Dutch drinking water. Here, chlorine appeared to be more problematic than monochloramine in terms of enriching pathogens and antibiotic resistance. We also noted that Dutch waters garnered more diverse microbial communities, with fewer DNA markers for pathogens and antibiotic resistance. In general, this research takes a key step towards optimizing application of residual disinfectants for control of both opportunistic pathogens and antibiotic resistance. Because disinfectants can have negative impacts on drinking water microbial communities when supplied insufficiently, it is important that the other features of in-building plumbing, such as the selection of pipe material or the hydraulics, facilitate disinfectants reaching all portions of plumbing and at the necessary concentrations. It is recommended that the selection process for disinfectant type and dose considers the plumbing materials and other conditions such that disinfection can be aimed towards controlling multiple opportunistic pathogens, which can vary in their susceptibility, and antibiotic resistance.
24

Effect of Water Chemistry, Pipe Material, Temperature and Flow on the Building Plumbing Microbiome and Opportunistic Pathogen Occurrence

Ji, Pan 12 October 2017 (has links)
The building plumbing microbiome has important implications, especially in terms of its role as a reservoir and conduit for the spread of opportunistic pathogens (OPs), such as Legionella pneumophila. This dissertation applied next-generation DNA sequencing tools to survey the composition of building plumbing microbiomes and assessed hypothetical factors shaping them. A challenge to identifying key factors shaping building plumbing microbiomes is untangling the relative contributions of influent water quality, provided by drinking water utilities, and those of building-level features, such as pipe materials. To this end, standardized pipe rigs were deployed at the treatment plants and in distal portions of the water distribution system at five water utilities across the eastern U.S. Source water and treatment practices appeared to be the overarching factors shaping the microbial taxonomic composition at the tap, with five key water chemistry parameters identified (total chlorine, pH, P, SO42- and Mg2+). Hot water plumbing is of particular interest because OPs tend to proliferate in warm water environments and can be inhaled in aerosols when showering. Two identical lab-scale recirculating hot water rigs were operated in parallel to examine the combined effects of water heater temperature set point, pipe orientation, and water use frequency on the hot water plumbing microbiome. Our results revealed distinct microbial taxonomic compositions between the biofilm and water phases. Importantly, above a threshold of 51 °C, water heater temperature, pipe orientation, and water use frequency together incurred a prominent shift in microbiome composition and L. pneumophila occurrence. While heat shock is a popular means of remediating L. pneumophila contamination in plumbing, its broader effects on the microbiome are unknown. Here, heat shock was applied to acclimated lab-scale hot water rigs. Comparison of pre- versus post- heat shock samples indicated little to no change in either the microbial composition or L. pneumophila levels at the tap, where both water heater temperature and water use frequency had the most dominant effect. Overall, this dissertation contributes to advancing guidance regarding where to most effectively target controls for OPs and also advances research towards identifying the features of a 'healthy' built environment microbiome. / PHD
25

Relationship Between Organic Carbon and Opportunistic Pathogens in Simulated Premise Plumbing Systems

Williams, Krista 20 September 2011 (has links)
Consumer exposure to opportunistic pathogens in potable water systems poses a significant challenge to public health as manifested by numerous cases of pneumonia, non-tuberculosis lung disease, and keratitis eye infections. Water utilities have extensive understanding in control of heterotrophic and coliform bacteria re-growth in water distribution systems via disinfection, control of assimilable organic carbon (AOC), and biologically degradable organic carbon (BDOC). However, much little is known about the effect of AOC on the proliferation of heterotrophic bacteria and pathogens within premise plumbing. This thesis is the first systematic examination of opportunistic pathogen persistence and amplification in simulated glass water heaters (SGWH) as a function of influent organic matter concentration. The role of plumbing conditions that may internally generate AOC is critically examined as part of this evaluation. Strong correlations were often observed between influent organic matter and heterotrophic bacteria in effluent of SGWH as indicated by 16S rRNA gene abundance (average R2 value of 0.889 and 0.971 for heterotrophic organisms and 16S rRNA respectively). The correlation was strongest if water turnover was more frequent (every 48-72 hours) and decreased markedly when water changes were less frequent (stagnation up to 7 days). No simple correlations were identified between the concentration of pathogenic bacteria (L. pneumophila, M. avium, A. polyphaga, and H. vermiformis) and AOC, although correlations were observed between M. avium and TOC over a limited range (and only for a subset of experiments). Indeed, there was little evidence that Legionella and Acanthamoeba proliferated under any of the conditions tested in this work. Parallel experiments were conducted to examine the extent to which factors present in premise plumbing (e.g. sacrificial magnesium anode rods, cross-linked polyethylene, nitrifying bacteria, and iron) could influence water chemistry and influence growth of bacteria or specified pathogens. Although these factors could strongly influence pH, dissolved oxygen concentrations, and levels of organic matter (e.g. iron, magnesium, nitrifying), there was no major impact on effluent concentrations of either heterotrophic bacteria or premise plumbing pathogens under the conditions investigated. While additional research is needed to confirm these findings, at present, there is no evidence of correlations between organic matter and pathogen concentrations from SGWH under conditions tested. Substantial effort was also invested in attempting to identify SGWH and oligotrophic nutrient conditions that would consistently support L. pneumophila and A. polyphaga amplification. A review of the literature indicates no prior examples of large scale amplification of these microorganisms at nutrient levels commonly found in synthesized potable water. It is likely that a complex combination of abiotic and biotic factors (i.e. micronutrients, necrotrophic growth, ambient water temperature, disinfectant type and dose, plumbing materials, water usage patterns), which are not yet fully understood, control the amplification and viability of these pathogenic organisms in premise plumbing systems. / Master of Science
26

Cycle-Free Twisted Face-Pairing 3-Manifolds

Gartland, Christopher John 29 May 2014 (has links)
In 2-dimensional topology, quotients of polygons by edge-pairings provide a rich source of examples of closed, connected, orientable surfaces. In fact, they provide all such examples. The 3-dimensional analogue of an edge-pairing of a polygon is a face-pairing of a faceted 3-ball. Unfortunately, quotients of faceted 3-balls by face-pairings rarely provide us with examples of 3-manifolds due to singularities that arise at the vertices. However, any face-pairing of a faceted 3-ball may be slighted modified so that its quotient is a genuine manifold, i.e. free of singularities. The modified face-pairing is called a twisted face-pairing. It is natural to ask which closed, connected, orientable 3-manifolds may be obtained as quotients of twisted face-pairings. In this paper, we focus on a special class of face-pairings called cycle-free twisted face-pairings and give description of their quotient spaces in terms of integer weighted graphs. We use this description to prove that most spherical 3-manifolds can be obtained as quotients of cycle-free twisted face-pairings, but the Poincaré homology 3-sphere cannot. / Master of Science
27

Impact of Polymeric Plumbing Materials on Drinking Water Quality and Aesthetics

Heim, Timothy Howard 19 June 2006 (has links)
The use of polymer pipes is now very common in home plumbing and other parts of the drinking water distribution system. Many taste and odor complaints in drinking water are known to originate from contact of water with materials. The ability of polymer pipes used in home plumbing to affect drinking water quality and aesthetics was investigated using the Utility Quick Test (UQT). Analysis of water quality and aesthetics were conducted in the absence of disinfectant and the presence of either chlorine or chloramines. A Flavor Profile Analysis (FPA) panel was trained according to Standard Methods 2170B to evaluate the organoleptic characteristics of the samples. Laboratory analyses were performed to determine levels of total organic carbon (TOC), disinfectant residual, pH and to attempt to identify specific volatile organics. The first part of this study investigated HDPE, cPVC and epoxy lined copper pipes using the UQT method. Both HDPE and epoxy-lined copper had significant effects on water quality and aesthetics during the approximately 10 day exposure of the UQT. HDPE and epoxy-lined copper leached significant amounts of TOC and consumed more disinfectant than controls, but in different amounts. cPVC was the most inert of the materials tested and had the least impact on water quality and did not contribute any significant odor. None of the pipes tested appeared to contribute trihalomethanes to drinking water, but further analysis revealed that the compounds may actually be generated and subsequently sorbed into pipe walls. These data show the effects of newly installed polymeric pipe materials and their potential to impact water quality in differing capacities. The second part of this study compared the results of the UQT on HDPE, epoxy lined copper, cPVC, PEX-a and PEX-b with the goal of comparing and contrasting how five different polymeric plumbing materials can impact drinking water quality. Results demonstrated the short-term ability of all pipe materials except cPVC to impact water quality and aesthetics. This data could potentially be useful in generating selection criteria for homeowners and plumbing professionals regarding the impact of newly installed plumbing materials. / Master of Science
28

Antecristais e xenocristais máficos em diques ultrabá¡sicos de tendência alcalina da Serra da Mantiqueira (SP) / Mafic antecrysts and xenocrysts in alkaline ultrabasic dykes of the Mantiqueira range (SP)

Silva, Julio Cesar Lopes da 22 February 2019 (has links)
Séries de diques máficos alcalinos fortemente a levemente insaturados em sílica ocorrem nas cercanias de Santo Antônio do Pinhal (SP) e Campos do Jordão (SP) na serra da Mantiqueira, SE Brasil. Estes intrudem o embasamento cristalino precambriano (Sul do Orógeno Brasília) e a intrusão máfica-ultramáfica alcalina Ponte Nova. As rochas alcalinas dessa região são cretáceas e compõem o magmatismo da província alcalina Serra do Mar (PASM). Em sua maioria, os diques são classificados como basaltos alcalinos e lamprófiros alcalinos. São porfiríticos, com a população de macrocristais formada principalmente por clinopiroxênio e olivina. Subordinadamente, macrocristais de kaersutita, sadanagaíta rica em titânio, e ocasionalmente, flogopita, enstatita, magnetita, espinélio e plagioclásio são registrados. Estes apresentam texturas de desequilíbrio, como sieve e embayment, que, associadas a estilos de zonamento complexo, indicam evolução magmática em sistema aberto. Este estudo envolve: (1) petrografia de detalhe por microscopia ótica e microscopia eletrônica de varredura, (2) análises químicas pontuais, de elementos maiores e menores por microssonda eletrônica e de elementos-traço por espectrometria de massa com plasma acoplado indutivamente e amostrador por ablação a laser (LA-ICP-MS), em diferentes zonas dos macrocristais máficos, e (3) geoquímica de rocha-total por fluorescência de raios X e ICP-MS. Estas análises foram realizadas com vistas à determinação da gênese destas populações de cristais zonados. A partir das composições obtidas, balanços de massa foram realizados para excluir a influência dos macrocristais nas composições globais dos corpos e obter uma estimativa composicional dos líquidos magmáticos, representados pela matriz fina a afanítica nestas rochas. As zonas dos macrocristais em equilíbrio com os líquidos calculados foram determinadas por meio da constante de equilíbrio de troca catiônica de Mg e Fe entre cristal e líquido, KdFe2+ -Mg2+ C/L . Estas relações de equilíbrio permitiram atribuir significados genéticos as zonas dos cristais, definindo-os como xenocristais, antecristais e fenocristais. Os primeiros (em desequilíbrio textural e químico com o a matriz) foram capturados e/ou reciclados de ambientes magmáticos precoces à consolidação da rocha, permitindo acessar processos magmáticos passados durante a evolução do sistema magmático. Xenocristais mantélicos foram indentificados exclusivamente em diques da suíte fracamente insaturada em sílica. Macrocristais de olivina zonada com centros Fo>90 e textura embayment, encontram-se ao lado de macrocristais de clinopiroxênio zonado com centro de diopsídio com cromo incolor, anédrico, com zonamento concêntrico step normal. Estes centros de diopsídio com cromo apresentam mg# (Mg/Mg+FeT em proporção molecular) 88-87, alto Ni, baixo Na2O, Al2O3, TiO2, Zn, Sc, Hf, Y, Zr, Sr e elementos terras raras (ETRs), compatíveis com peridotitos fáceis granada e granada-espinélio. Nessa mesma ocorrência, centros de macrocristais de piroxênio são classificados como enstatita (xenocristais) e apresenteam textura sieve, zonamento concêntrico step reverso, altos teores de MnO, Ni, Zn e muito baixos de ETRs. Quanto aos antecristais, cristais em desequilíbrio químico e textural com a matriz mas cogenéticos ao sistema magmático, os clinopiroxênios destacam-se nos diques fortemente insaturados em sílica. Os centros desses macrocristais são classificados como diopsídio (por vezes com cromo ou com sódio), augita, hedenbergita e egirina-augita. O diopsídio é incolor, subédrico, com textura glomeroporfirítica, sieve, zonamento setorial e concêntrico step reverso. Este centro antecristalino incolor apresenta alto mg# (83-80), Cr2O3, Ni, Sc, baixo Na2O, Zn e valores intermediários de Zr, Y, Hf e Sr, quando comparado aos demais antecristais. Centros verdes de augita e egirina-augita são encontrados nos diques de ambas as séries e apresentam textura embayment, sieve e zonamento concêntrico step. No geral os centros verdes tem baixo mg# (70-40), Cr2O3, alto MnO, Na2O, Zn, mas diferentes teores de MnO, Na2O, Li, Sc, Hf, Y, Zr, Sr e ETRs. Ti-augita, quimicamente classificada como diopsídio subsilícico com titânio, é euédrica, com textura glomeroporfirítica, zonamento concêntrico oscilatório e setorial e observada como borda em todos os macrocristais de clinopiroxênio, além de compor a matriz e agregados (textura glomeroporfirítica) com macrocristais subédricos de olivina (Fo<88). Estes dois últimos tipos, em desequilíbrio químico com a matriz hospedeira mas com texturas de cogeneticidade ao sistema magmático, são antecristais de um estágio magmático posterior a cristalização dos antecristais e captura dos xenocristais e em menor profundidade. Kaersutita euédrica a subédrica, com textura glomeroporfirítica, esquelética e zonamento concêntrico oscilatório é o cristal predominante nos lamprófiros alcalinos. Este também ocorre como macrocristal anédrico com textura sieve em alguns diques de olivina basalto. Nos anfibólios destaca-se o enriquecimento em Ba, Sr, Y, Nd, Zr e ETRs inversamente proporcional ao MgO. Flogopitas com titânio são observadas principalmente na matriz dos diques máficos alcalinos da Mantiqueira. Porém macrocristais são raros e observados com zonamento concêntrico step e setorial. Nos cristais de flogopita da matriz, ao aumento de vacância no plano octaédrico é proporcional as altas concentrações de Ti, Nb, Zr, Sr, Y e Li, quando comparado ao macrocristais. Os xenocristais de olivina e diopsídio com cromo, encontrados nos diques máficos da série fracamente insaturada em sílica, indicam incorporação de rocha encaixante mantélica e/ou da fonte. Já os magmas máficos fortemente insaturados em sílica se mostraram híbridos, a partir de modelagem com elementos-traço, entre a mistura de líquidos alcalinos máficos e félsicos, responsáveis por cristalizar em estágios precoces, os antecristais de clinopiroxênio nos diques. Um estágio em menor profundidade é indicado pela presença em todos os diques de fenocristais e antecristais de Ti-augita como borda, macrocristal isolado ou com textura glomeroporfirítica, cristal na matriz, sendo, por vezes, associado a olivina e anfibólio. Esta diversidade de macrocristais pode ser explicada pelo modelo complex plumbing system, onde a interconexão entre diferentes magmas, ao longo de distintos estágios com diversas encaixantes, sob profundidades diferentes da litosfera, se mostra eficiente na produção das feições petrográficas e químicas destas rochas por meio dos processos de mistura de magmas e incorporação da rocha encaixante durante a ascensão litosférica desses diques ultrabásicos alcalinos do Cretáceo na região ocidental da serra da Mantiqueira, província alcalina Serra do Mar. / Weakly to strongly silica-undersaturated mafic alkaline dike series occur nearby Santo Antonio do Pinhal (SP) and Campos do Jordão (SP) in a restricted area of the Mantiqueira range, SE Brazil. These are intrusive in the Precambrian crystalline basement (south of the Brasília orogen) and in the Ponte Nova mafic-ultramafic alkaline massif. These alkaline rocks are Cretaceous and are grouped as part of the Serra do Mar alkaline province (PASM). In the majority, the dikes are classified as alkaline basalts and alkaline lamprophyres. They are porphyritic, with the macrocryst population having clinopyroxene and olivine as main phases. Subordinatedly, kaersutite, and occasionally, phlogopite, enstatite, magnetite, spinel and plagioclase were found. These macrocrysts present desequilibrium textures, such as sieve and embayment, combined with complex zoning styles, which indicate a open-system magmatic evolution. The study involves: (1) detailed petrographic analyses by optical microscopy and scanning electron microscopy, (2) quantitative punctual analyses of major and minor elements by electron microprobe and trace element by laser ablation - inductively coupled plasma mass espectrometry (LA-ICP-MS) in different horizons of the main macrocrystic phases, and (3) whole-rock geochemistry by X-ray fluorescence and ICP-MS. These determinations were collected focusing in the determination of the genesis of each zone of zoned crystals. From the obtained compositions, mass balance calculations were done to exclude the macrocryst influence in the bulk compositions of the bodies and to have a compositional estimative of the melts, represented by the fine-grained to aphanitic matrices of these rocks. The crystalline zones of macrocrysts in equilibrium with the calculated melts were defined using the Mg-Fe exchange equilibrium constant between minerals and liquid, KdFe2+-Mg2+ C/L . The equilibrium relationships allowed the designation of genetic meanings to the the crystalline zones, being these classified as xenocrysts, antecrysts and phenocrysts. The first two types (in textural and chemical disequilibrium with the matrices) were captured and/or recycled from an early magmatic environment, allowing to access the former magmatic processes during the evolution of the system. Mantle xenocrysts were only identified in dikes from the weakly silica-undersaturated series. Macrocrysts of zoned olivine with cores having Fo > 90 and embayment texture were found together with zoned clinopyroxene macrocrysts, presenting incolor, anhedral Cr-diopside cores with normal concentric step zoning. These Cr-diopside cores have mg# (Mg/Mg+FeT in molecular proportions) 88-87, high Ni values and low Na2O, Al2O3, TiO2, Zn, Sc, Hf, Y, Zr, Sr and rare earth elements (REEs). These compositions are compatible with the garnet and garnet-spinel peridotite facies. On the same occurrence, cores of macrocrystic pyroxene are classified as enstatite (xenocryst) and present sieve texture, concentric reverse step zoning, and high levels of MnO, Ni, Zr and very low of REEs. Antecrysts, crystals in chemical and textural disequilibrium with the matrices but cogenetic to the magmatic system, were mainly formed by cores of clinopyroxene macrocrysts in strongly silica-undersaturated mafic alkaline dikes. The cores of these ones are classified as diopside (sometimes Cr-bearing of Na-bearing), augite, hedenbergite and aegirine-augite. The diopside is incolor, subhedral, with glomeroporphyritic and sieve textures, setorial and concentric reverse step zonings. They present higher mg# (83-80), Cr2O3, Ni, Sc values, lower Na2O and Zn, and intermediate Zr, Y, Hf and Sr concentrations when compared to the other antecryst. Green cores of augite and aegirine-augite are found in dikes of all series and present embayment and sieve textures and concentric step zoning. These have low mg# (70- 40), Cr2O3, high MnO, Na2O and Zn, but wide ranges of MnO, Na2O, Li, Sc, Hf, Y, Zr, Sr and REEs. Ti-augite, chemically classified as subsilicic Ti-bearing diopside, is euhedral, with concentric oscillatory and setorial zonings and found as rims in all clinopyroxene macrocrysts, as matrix crystals and as agregates (glomeroporphyrithic texture) with subhedral olivine macrocrysts (Fo<88). Some of these two minerals zones are in chemical disequilibrium with the matrix but with textural equilibrium of magmatic system, being classified as antecrysts from a next magmatic stage of antecrystals cristalization and xenocryst incorporation. Other horizons of Ti-augite are phenocrysts, in chemical equilibrium with the host melt. Euhedral to subhedral kaersutite, with glomeroporphyritic and skeletal textures and oscillatory concentric zoning is predominant in alkaline lamprophyres. Anhedral kaesutite crystals with sieve texture occurs as macrocrysts in some olivine basalts dikes. In these amphiboles, the enrichment in Ba, Sr, Y, Nd, Zr and REEs present negative correlation with MgO contents. Ti-bearing phlogopites are found mainly in the matrices of the mafic dikes from the Mantiqueira range. However, macrocrysts are rare and found with anhedral habit and concentric step and setorial zonings. The increase of vacancies in octaedric plane of the matrix crystals phlogopite is proportional with the concentrations of Ti, Nb, Zr, Sr, Y and Li, when compared with the macrocryst compositions. The olivine and Cr-diopside xenocrysts found in the mafic dikes from the weakly sílica-undersaturated series indicate the incorporation of mantle host rocks and/or source rocks. Otherwise, the magmas from the strongly sílica-undersaturated series are considered hybrids, based on the trace-element mixing modelling of alkaline mafic and felsic melts. These compositionally contrasting liquids are the responsible for the crystallization, in the earlier stages, of the different families of clinopyroxene antecrysts. On next stage, at lower depth, is indicated by the presence of phenocrysts and antecrysts of Ti-augite as rims, isolated or aggregate macrocrysts and matrix crystals, sometimes associated with olivine and amphiboles. This macrocryst diversity can be explained by the complex plumbing system model. In this model, the interconection between several magma reservatories along distinct evolution stages, with different host rocks during their ascent under several depths in the lithosphere, is considered a efficient way to explain the petrographic and chemical features found in these rocks. Processes of magma mixing and the incorporation of host rocks during the lithospheric ascent are registere for the ultrabasic alkaline Cretaceous dikes of the Mantiqueira range, Serra do Mar alkaline province.
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Aproveitamento de água pluvial em edifícios residenciais multifamiliares na cidade de São Carlos. / Rainwater harvesting in a residential tall building in the city of São Carlos.

Campos, Marcus André Siqueira 06 May 2004 (has links)
Made available in DSpace on 2016-06-02T20:09:10Z (GMT). No. of bitstreams: 1 DissMASC.pdf: 3170204 bytes, checksum: 83bd0768232793a648b29a0d4da7f753 (MD5) Previous issue date: 2004-05-06 / Financiadora de Estudos e Projetos / The potable water scarcity afflicts the begging of the 21st Century, being today, one of the main worries of the manhood. This way, it becomes necessary to reduce the per capita consumption. From the actions that promote the racional use of water, the technological ones seems to be , in the most of the cases, the most recomended to reduce the consumption without being necessary radical changes of the users. One of these technologies is the rainwater harvesting. This one erges as an action of good perspectives since it subistitutes the use of potable water in activities where it is not necessary a good quality water, younder, it will reduce the amount of stormwater in the public drainage net, working as a non-structural action of urban drainage. The lack of kwondlege as well a the real advantages that a rainwater system can bring to a builind, is the points to find out about this issue.. At this paper, it seeked to clear this techonolgy up with the study of national and international examples . It also seeked the cistern sizing, getting the best results to technical and economical issues, as well, as procedures to design and to mantain the devices that make part of the system used in this study. Besides that, it studied the changes that would be necessary to build the system, and the possibles changes at the work routine of the construction company. It also studied the financial feasibility of the investiment of this interprisement, checking the real economical advantages that can be get. It is waited that this research contributes to the development of this techonology, contributing to Racional use of water in residential tall buildings. / A escassez de água potável atormenta o início do Século XXI, sendo hoje uma das principais preocupações da humanidade neste século que começa. Dessa forma, surge a necessidade de redução do consumo per capita. Dentre as ações que promovem o uso racional da água, as tecnológicas parecem ser , na maioria dos casos, as mais recomendadas para reduzir o consumo sem que seja necessário mudanças radicais nos hábitos dos usuários. Entre estas, o aproveitamento de água pluvial surge como uma ação de boas perspectivas, pois substitui o uso de água potável onde a qualidade desta não é necessária e, a retirada desta diminuirá a quantidade de volume de água pluvial lançada na rede pública de drenagem, funcionando como uma medida não-estrutural de drenagem urbana. A falta de conhecimento técnico bem como das reais vantagens que um sistema de aproveitamento de água pluvial poderá trazer para uma edificação são as principais incógnitas desse assunto. Neste trabalho buscou-se clarear a tecnologia, com o estudo de diversos casos nacionais e internacionais. Também se buscou realizar o dimensionamento de forma mais correta e econômica, bem como listar procedimentos para elaboração e manutenção de todos os elementos constituintes do sistema utilizado no edifício objeto de estudo. Além disto, verificou-se as possíveis interferências nos processos construtivos, além de alterações das rotinas de trabalho da construtora, além do estudo da viabilidade financeira do empreendimento, verificando as reais vantagens da implantação do sistema neste caso. Espera-se que esse trabalho contribua para o desenvolvimento de uma tecnologia específica para o uso racional de água.
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A study in consumers willingness to purchase water efficient fittings

Dumalisile, Sinovuyo 04 1900 (has links)
Thesis (MBA)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The continuous growth in the world’s population together with the increasing scarcity of water resources, especially drinkable water, has cultivated an environmentally-conscious society. As consumers are looking for eco-friendly alternatives or methods, manufacturers are including environmentally-friendly (EF) products in their product mix to address this topic. However, there seems to be a disconnect between manufacturers of EF product solutions and consumers. Consumers are either not aware of EF products or they are still hesitant in adopting environmentally-friendly products as the perception is that they are either too expensive or there is something amiss with the product’s functionality. It is up to suppliers and marketers of EF goods to do a better job of educating consumers about their products. This research study was conducted to understand the domestic consumer’s ecological behaviour and key influencing factors when purchasing water-efficient fittings. The literature review in this study gives us background on the status quo in terms of climate change, the green consumer, and water supply issues. A survey was conducted amongst domestic consumers in the plumbing retail environment to test their willingness to purchase water-efficient fittings based on their profile, habits and key influencing factors. The profile of the respondent showed a consumer who is more affluent. The water-efficient consumer’s primary concern is to save costs by reducing their water bill. Cost saving is the key influencing driver in terms of consumer’s willingness to purchase water-efficient fittings.

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