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Turse, Carol Louise. "Testing the hydrogen peroxide-water hypothesis of life on Mars using the differential scanning calorimeter as an analog for the TEGA instrument on the Mars Phoenix lander." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Summer2009/c_turse_072309.pdf.
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Thesis (M.S. in environmental science)--Washington State University, August 2009.Title from PDF title page (viewed on Sept. 22, 2009). "School of Earth and Environmental Sciences." Includes bibliographical references (p. 92-97).
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Nyirenda, Michael. "Open Waters - Digital Twins With use of Open Data and Shared Design for Swedish Water Treatment Plants." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-281703.
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Digital twins (DTs) are digital copies of a physical system that incorporates the system environment, interactions, etc. to mirror the system accurately in real time. As effective decision support systems (DSS) in complex multivariate situations, DTs could be the next step in the digitalization of water management. This study is done in cooperation with the Open Waters project group at the Swedish environmental research institute (IVL). The aim of the project group is to investigate the possibility to realize DTs with the use of open data (OD), and shared design (SD), in Swedish water management while also promoting ecosystems for innovation in virtual environments. This study will aid the project group by bridging the gap between project stakeholders and water managers. A DSS developed by IVL for automatic dosage of coagulants in water treatment which is based on the same industry 4.0 technology as DTs will be evaluated as a possible starting point for DTs, OD, and SD. In depth interviews were held with representatives from water management, and experts in DTs, OD, and SD. This was to identify key opportunities and threats, and to understand water managers perception and opinion of the project. This is complimented by a brief review of Swedish water management, and the international state of DTs. There were 4 main opportunities and threats. Challenges and goals are very similar between different WTPs Water managers are already collaborating to reach common goals WTPs are unique in terms of treatment steps and composition/properties of raw water WTPs are objects of national security which raises questions regarding safety when digitalization is discussed.Digitala tvillingar (DT) är digitala kopior av fysiska system som inkluderar systemets miljö, interaktioner, etc. för att noggrant spegla systemet i realtid. Som effektiva beslutsunderlag i komplexa, multivariabla situationer har DT fått uppmärksamhet inom vattensektorn och kan vara nästa steg i industrins digitalisering. Denna studie utförs i samarbete med svenska miljöinstitutets (IVLs) projektgrupp Open Waters. Syftet är att utforska möjligheten att förverkliga DT med hjälp av öppna data (OD) och delad design (SD) i den svenska vattensektorn, samt att främja innovationsekosystem i virtuella miljöer. Målet med denna studie är att överbygga klyftan mellan projektgruppen och dess målgrupp. Till hjälp kommer den IVL utvecklade DOS-modellen för automatisk dosering av fällningskemikalier för vattenrening. Denna är baserad på samma industri 4.0 teknologi som DT och ses som en startpunkt för DT, OD, och SD. Djupintervjuer hölls med representanter inom vattensektorn, såväl som experter inom DT, OD, och SD. Målet med detta var att identifiera centrala möjligheter och hot för projektet, samt för att förstå vattensektorns bild och åsikt av DT. Detta kompletteras med en övergripande genomgång av den svenska vattensektorn, och DT. 4 huvudsakliga möjligheter och hot identifierades. Utmaningar och mål är väldigt lika mellan olika vattenverk Det sker redan samarbeten i vattensektorn när gemensamma mål identifieras Vattenverk är unika i förhållande till reningssteg och råvatten Vattenverk är skyddsobjekt vilket höjer frågor gällande informationssäkerhet när digitalisering diskuteras.
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Rutberg, Michael J. (Michael Jacob). "Modeling water use at thermoelectric power plants." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74674.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 74-77).
The withdrawal and consumption of water at thermoelectric power plants affects regional ecology and supply security of both water and electricity. The existing field data on US power plant water use, however, is of limited granularity and poor quality, hampering efforts to track industry trends and project future scenarios. Furthermore, there is a need for a common quantitative framework on which to evaluate the effects of various technologies on water use at power plants. To address these deficiencies, Part 1 of this thesis develops an analytical system-level generic model (SGEM) of water use at power plants. The S-GEM applies to fossil, nuclear, geothermal and solar thermal plants, using either steam or combined cycles, and outputs water withdrawal and consumption intensity, in liters per megawatt-hour. Two validations of the S-GEM are presented, one against data from the literature for a variety of generation types, the other against field data from coal plants in South Africa. Part 2 of the thesis then focuses on cooling systems, by far the largest consumers of water in most power plants. The water consumption of different cooling systems is placed on a common quantitative basis, enabling direct comparison of water consumption between cooling system types, and examination of the factors that affect water consumption within each cooling system type. The various cost, performance, and environmental impact tradeoffs associated with once-through, pond, wet tower, dry, and hybrid cooling technologies are qualitatively reviewed. Part 3 examines cooling of concentrating solar power (CSP) plants, which presents particular problems: the plants generate high waste heat loads, are usually located in water-scarce areas, and are typically on the margin of economic viability. A case study is conducted to explore the use of indirect dry cooling with cold-side thermal energy storage, in which cooling water is chilled and stored at night, when ambient temperatures are lower and the plant is inactive, and then used the following day. This approach is shown to hold promise for reducing the capital, operational, and performance costs of dry cooling for CSP.
by Michael J. Rutberg.
S.M.
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Miranda, Casey R. "Effects of Recycled Water On Landscape Plants." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/354.
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ABSTRACT EFFECTS OF RECYCLED WATER ON LANDSCAPE PLANTS Casey Ray Miranda Recycled water is water that has been previously used, has suffered a loss of quality, and has been properly treated for redistribution (Wu et al. 2001). The use of recycled water as an alternative to fresh water in the landscape can have positive and negative effects. Experimentation on 40 different plant species during a 32 week period (2 phases of 16 weeks), was conducted to analyze the effects of recycled water irrigation on the appearance of landscape plants. Each species of plant was planted into 10 individual number 2 pots and irrigated with recycled water daily. Media and water were tested for nutrients and other constituents. In phase I there were four different species of grasses and grass-like plants, five different perennials, five species of shrubs, and four annuals tested; while phase II tested four species of herbaceous perennials, eight different species of shrubs, six species of groundcovers, and four species of annuals. All tests were conducted at the Paso Robles Waste Water Treatment Plant. Of the grasses and grass like species Yucca spp. and Buchloe spp. performed best. Osteospermum fruticosum, Lavandula angustifolia, Rosmarinus officinalis, Phormium tenax, and Pennisetum setaceum had the best appearance of the herbaceous perennials tested. For the shrubs, Coprosma repens, Cistus purpureus, Dodonea viscosa, Eleagnus pungens, Baccharis pilularis, Ceanothus thysiflorus, Thuja orientalis, and Nerium oleander had the best appearance when irrigated with recycled water. The best annuals were Senecio cineraria, Antirrhinum majus, Primula spp., Viola spp., and Calendula officinalis. Of the groundcovers Heuchera spp., Lonicera japonica, Vinca major, Hedera helix, and Ceanothus griseus had the best results. From the experiment a list of tolerant and non-tolerant plants was compiled (Appendices 1 and 2). While many plants were capable of developing and growing normally, other plants were sensitive to recycled water irrigation. In order to prevent salt damage to plants and expand the use of recycled water, salt tolerance of landscape plant material must be identified (Niu et.al, 2006).
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Momba, MNB, CL Obi, and P. Thompson. "Survey of disinfection efficiency of small drinking water treatment plants: Challenges facing small water treatment plants in South Africa." Water SA, 2008. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001759.
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Abstract
A survey involving 181 water treatment plants across 7 provinces of South Africa: Mpumalanga, Limpopo, North West,
Free State, KwaZulu-Natal, Eastern Cape and Western Cape was undertaken to identify the challenges facing small water
treatment plants (SWTPs) in South Africa . Information gathered included ownership and design capacity of the plants,
water sources, and various methods of disinfection, equipment currently employed and performance of the treatment plants.
In general, the majority (over 80%) of the SWTPs surveyed in the designated provinces were owned by the district municipalities.
The designed capacities of these plants varied between 1 and 60 Mℓ/d; the smallest capacity was 100 m3/d and the
largest 120 Mℓ/d. The small water treatment plants abstracted their raw water from either surface or groundwater or a combination
of both water sources with greater preponderance for surface water sources (over 86%). Water treatment practices
were noted to be the conventional types mainly coagulation, flocculation, sedimentation, filtration and disinfection. Two
types of coagulants namely polyelectrolyte (66%) and alum (18%) were commonly used by the water treatment plants across
the provinces studied. Rapid gravity filtration, pressure filter and slow sand filtration systems accounted for 60%, 23% and
9% of the filtration systems across the provinces, respectively. The predominant types of disinfectants employed were chlorine
gas (69%) followed by sodium (15%) and calcium (14%) hypochlorite. Over 50% of the various SWTPs did not comply
with the SANS 241 Class I (< 1 NTU) and Class II (1 to 5 NTU) recommended turbidity values. The recommended target
range of 0.3 to 0.6 mg/ℓ free chlorine residual concentrations at the point of use was not always met by 40% of the plants.
Seventy percent of the SWTPs complied with the SANS 241 criteria of microbiological safety of drinking water vis-à-vis
total and faecal coliforms. Operational problems affecting the efficiency of small water treatment plants included: inability
to appropriately determine the flow rate, chemical dosage and turbidity, lack of chlorine residual at the point of use and lack
of water quality monitoring. To produce safe drinking water, appropriate operational practices must be implemented in all
small water treatment plants.
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Nordgren, Lars. "Simulations of water delivery to the inner planets." Thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-211217.
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It is generally assumed that the temperature in the inner part of the primordial nebula was too high to form and agglomerate ice bodies. Yet, water is present in most of the terrestrial planets of our solar system. To investigate the reason for this we concentrate on comets as a potential water deliverer to the inner planets. The data for this work is taken from 3D simulations of comet trajectories inside a gas-dust disk with embedded planet embryos. We have developed a MATLAB code that could read data files from these simulations containing orbital elements of the comets and planetary embryos. Comets experience inward migration due to friction with the remains of the disk. We study comets of four different sizes. We find that smaller comets migrate faster and therefore spend less time in the inner solar system. Smaller comets are numerous and are therefore destroyed in greater numbers than the larger comets. Larger comets on the other hand slow their migration and spending much more time among inner planets they are more massive and produce more massive collisions with the inner planets than the smaller comets. Therefore are larger comets a more promising source of water delivery to the inner planets. In Studying individual collisions we observe that a typical interaction involves regular close encounters with the same embryo during periods of 100000 years or more before the two orbits intersect. This also tells us that with a large number of comets expected at this stage of solar system evolution the collective effect of comets on low-mass planetary embryos may be significant.
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Parsons, N. F. "The interaction of water waves with thin plates." Thesis, University of Manchester, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508749.
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Daniels, Mark J. "Characterization of water channel proteins (Aquaporins) in plants /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9735273.
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Goldenetz, Jolie A. "Southwest Gardens: Matching Plants with Available Water Resources." Arizona-Nevada Academy of Science, 2007. http://hdl.handle.net/10150/296683.
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Montaña, Guerra Montserrat. "Optimization of alpha emitter's determination in water. Behavior of radionuclides in water treatment plants." Doctoral thesis, Universitat Politècnica de Catalunya, 2013. http://hdl.handle.net/10803/129458.
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La determinació de l’índex alfa total en aigües és d’interès per ser un dels paràmetres inclòs en la legislació nacional e internacional associada a la qualitat de l’aigua per al consum humà. Aquest índex informa de la concentració d’emissors alfa continguts en l’aigua referits a un patró emissor alfa. Concretament en el nostre país, el control de la qualitat de l’aigua està regulat pel Reial Decret 140/2003.
La determinació de l’índex d’alfa total en aigües és un assaig aparentment senzill, però a conseqüència de la variabilitat isotòpica que pot presentar una aigua i els procediments utilitzats, es poden obtenir resultats molt diferents, inclús en ordres de magnitud. A més a més, en certs casos el valor de l’índex alfa total no concorda amb el valor obtingut al sumar les activitats dels emissors alfa determinats en la mostra d’aigua.
Per tot això es considera necessari dur a terme un estudi experimental, en el qual es determinin tots els possibles factors que influeixin en la variabilitat dels resultats i realitzar un procediment suficientment detallat en el qual s’estableixi tant l’ interval de validació com les condicions més adequades d’utilització, de forma que es pugui garantir que el resultat que s’obté sigui el més representatiu possible i que aquesta variabilitat romanent es tingui en compte en la determinació de la incertesa associable al resultat.
Per una altra banda, a causa de la gran importància de l’aigua i les cada cop més exigents disposicions legals en quant a la depuració d’aigües residuals i tractament d’aigua potable, la construcció d’estacions de tractaments han anat incrementant notablement en els últims anys en un gran nombre de països. Com a conseqüència, grans quantitats de residus sòlids o llots son generats cada any com a subproducte d’aquestes plantes de tractament, per als quals s’apliquen diferents alternatives d’aprofitament i eliminació.
Durant els processos habituals de tractament per a l’obtenció d’aigua potable i de depuració d’aigua residual, els isòtops radioactius es poden distribuir en les diferents etapes dels cicles de tractament, com les resines d’intercanvi, carbó actiu, filtres, membranes, materials absorbents i finalment en els subproductes produïts (fangs o llots), on es pot concentrar-se un percentatge elevat d’isòtops radioactius. Les aigües més afectades per la radioactivitat natural son les aigües d’aqüífers subterranis, ja que els processos de circulació lenta afavoreixen la seva incorporació. Els isòtops presents generalment a les aigües són els isòtops naturals d’Urani i Radi, 210Pb, 210Po, 222Rn i el 40K. També existeix la possibilitat de contaminació amb isòtops d’origen artificial que provenen de la indústria nuclear i de les probes nuclears.
Per tant es considera d’interès realitzar un estudi detallat de la distribució dels isòtops radioactius en les diferents fases dels processos de potabilització i depuració convencionals o amb nous mètodes i en els subproductes generats per tal de poder valorar el possible impacte radiològic associat a la potabilització i reutilització de les aigües i dels subproductes.Gross alpha activity measurement is one of the simplest radioanalytical procedures which are widely applied as screening techniques in the fields of radioecology, environmental monitoring and industrial applications. It is used as the first step to perform a radiological characterization of drinking water. According to the WHO guidelines (2011), this screening parameter must be measured in drinking water to ensure that it is safe for consumption. Different methods are used to measure gross alpha activity. Two of them, the classic ones, are based on evaporation (EPA, 1980) or co-precipitation (EPA, 1984) of the sample, using either a gas proportional counter or a solid scintillator detector. Another alternative method based on concentration of the sample and measurement by liquid scintillation counting (ASTM, 1996), is being increasingly used. The gross alpha activity of a water sample is an estimate of the actual alpha activity of the water sample (excluding radon). However, it is usually considered that gross alpha activity must be very close to the sum of alpha emitter activities, though in general this is not the case. There are many other factors (e.g., alpha particle energies, calibration standard used, time elapsed from sample preparation to measurement and variability of the results between methods) that affect the gross alpha measurement causing major differences between the gross alpha activity values and the sum of the activities of the main alpha emitters. For this reason, we propose to conduct an eminently experimental study to determine most of the possible factors that may be involved in the above mentioned variability of the results. In addition, we intend to propose a detailed procedure on that basis to establish both their range of validity and the most suitable conditions for their use, thereby ensuring: (A) that the result obtained is the most representative of the sample's real total alpha activity; (B) that it is subject to the lowest technically possible variability; and (C) that this remaining variability is taken into account in determining the uncertainty associated with the result. In this context, we propose to study these aforementioned considerations using the co-precipitation method. Aditionally, given the problems with the scarcity and quality of water, the implementation of water treatment plants has been significantly increasing over the last years in several countries. Consequently, large quantities of solid wastes or sludge are generated every year which can be re-used for different applications. These solid wastes may contain all kind of pollutants, including significant levels of radioactivity. For these reasons, it is considered important studying the occurrence and behavior of radioactivity in water treatment plants. Although radioactivity in water treatment plants has been studied by some authors, we propose an original work analyzing the radioactive temporal evolution in different water treatment plants in which drinking and wastewater are treated. These plants have been selected taking into account both variations in water source and the treatment applied. This thesis contributes to these goals by analyzing the factors that affect the gross alpha measurement, involving an optimization and validation of the co-precipitation method and studying the behavior of radionuclides in water treatment plants. To this end, Part I provides a comprehensive analysis for the optimization and validation of the gross alpha activity determination using the co-precipitation method. Then, in Part II, we present a set of case studies related to the radionuclide behavior and the temporal evolution of the radioactivity in different drinking water and wastewater treatment plants.
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Rosli, Masli Irwan. "Water management in PEM fuel cell gass distributor plates." Thesis, University of Leeds, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.574597.
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Proton exchange membrane fuel cells are well known to be prormsmg alternative energy converters because of their advantages in power efficiency and low emission. One of the major components in a proton exchange membrane fuel cell is the gas flow-field channels where the reactant gases are distributed to the catalyst layers and the liquid water is accumulated. In this investigation, a fuel cell test station was designed and fabricated in order to perform experimental investigations on the proton exchange membrane fuel cell. Direct visualisation techniques have been applied in the experimental investigations in order to capture visuals of the liquid water behaviour in the gas flow-field channels. The visuals were captured by using a transparent proton exchange membrane fuel cell which has been specifically designed for this investigation. The power performance of the transparent proton exchange membrane fuel cell has been evaluated at the various cathode gas inlet relative humidity's and gas inlet flow rates. Both 2D and 3D proton exchange membrane fuel cell models have been developed in this investigation in order to simulate the power performance of the proton exchange membrane fuel cell and to predict water profiles in the gas flow- field channels. The operating conditions for the experimental investigations and the produced data, namely the power performance curves and the visuals of the liquid water distributions in the gas flow-field channels have been used in order to set up the models and also to validate the simulation results. Observations on the visualisation experimental investigations on the transparent proton exchange membrane fuel cell have revealed some very interesting liquid water behaviours, namely the cyclic formation of the liquid water and the positive effect of the water slug movements in the gas flow-field channels. The gas inlet relative humidity was observed to significantly affect to this liquid water behaviour. In addition, the cathode gas inlet relative humidity was observed to produce a larger effect compared to the anode gas inlet relative humidity o~ the power performance , of the proton exchange membrane fuel cell. The developed 2D model was tested and it was found to be capable of producing good results in the prediction of the power performance of the proton v exchange membrane fuel cell. However, the 3D model was found to perform better, u, in particular the relative humidity profiles over the whole region of the gas flow- field channels. This provides further information on the formation of the liquid water in the gas flow-field channels and this can be evaluated in the water management of the proton exchange membrane fuel cell.
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Wilson, Jessica M. "Challenges for Drinking Water Plants from Energy Extraction Activities." Research Showcase @ CMU, 2013. http://repository.cmu.edu/dissertations/254.
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Fossil-fuel associated wastewaters have the potential to affect drinking water quality through surface water disposal. These wastewaters are elevated in certain components, such as bromide, which can affect drinking water quality for consumers. In Pennsylvania, the recent expansion of drilling in the Marcellus Shale has significantly increased the volume of produced water that must be managed. It is essential to determine the potential of this produced water to affect surface water. Assessment of the characteristics of this produced water, as well as other fossil-fuel associated wastewaters, will enable evaluation of the effects of surface water disposal practices on drinking water.
The objective of this work is to identify the challenges for drinking water plants from management of wastewaters associated with energy extraction activities. Focusing on regional activity in Pennsylvania, a state with significant energy and water resources, this work has reached three conclusions. First, increases in the volume of oil and gas produced water disposed of to surface water from 2008 to 2010 increased the total dissolved solids and bromide loads in Pennsylvania, which affected concentrations of those constituents at the drinking water intakes. Changes to the management of this produced water in 2011 significantly decreased the total dissolved solids and bromide loads, and thus the concentrations at the drinking water intakes. Second, regional fossil-fuel wastewaters can be differentiated by their anion ratios, and the use of anion ratios in conjunction with concentration data enables evaluation of the extent of mixing between oil and gas produced waters and freshwater. This method can be used to track water quality changes in areas experiencing fossil fuel activity and provide insight into causes of observed changes. Finally, high bromide concentrations at drinking water intakes in 2010 were not attributed solely to low flow conditions in the river. River conditions were similar in 2010 and 2012, but significant load reductions improved water quality in 2012. The decrease in bromide loading is likely associated with a voluntary ban on the use of surface-discharging treatment plants for shale gas produced water disposal in the region.
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Terry, Christian James. "Gene expression and ABA biosynthesis in water stressed plants." Thesis, University of Nottingham, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308310.
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Sarafian, Adam Robert 1986. "Water and volatile element accretion to the inner planets." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115785.
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Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2018.Cataloged from PDF version of thesis.
Includes bibliographical references.
This thesis investigates the timing and source(s) of water and volatile elements to the inner solar system by studying the basaltic meteorites angrites and eucrites. In chapters 2 and 3, I present the results from angrite meteorites. Chapter 2 examines the water and volatile element content of the angrite parent body and I suggest that some water and other volatile elements accreted to inner solar system bodies by ~2 Myr after the start of the solar system. Chapter 3 examines the D/H of this water and I suggest it is derived from carbonaceous chondrites. Chapter 4, 5, 6, and 7 addresses eucrite meteorites. Chapter 4 expands on existing models to explain geochemical trends observed in eucrites. In Chapter 5, I examine the water and F content of the eucrite parent body, 4 Vesta. In chapter 6, I determine the source of water for 4 Vesta and determine that carbonaceous chondrites delivered water to this body. Chapter 7 discusses degassing on 4 Vesta while it was forming.
by Adam Robert Sarafian.
Ph. D.
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Tecle, Aregai. "Water Consumption of Common Plants in the Southwest U.S." Arizona-Nevada Academy of Science, 2004. http://hdl.handle.net/10150/296607.
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Köry, Jakub. "Multiscale modelling of nutrient and water uptake by plants." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/50425/.
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Growing populations in combination with the effects of climate change make the task of ensuring global food security in the future challenging. Water and various nutrients contained in soils are essential for the growth and survival of crop plants. Processes governing the dynamics of these substances are often highly complex and occur at various spatial scales. Because of that, and also due to limited possibilities for direct studies of soil processes in general, the ability to model such processes across these scales will most likely be crucial to address the food security challenge. Therefore, in this thesis, we model water and nutrient uptake by plant roots at various spatial scales. As all our models will be simulated numerically, we first test whether the software used throughout this thesis (FEniCS) gives us reliable numerical results (Chapter 2). We then proceed with the central part of this thesis, where we study nutrient uptake by root hairs using the method of homogenisation (introduced in Section 1.4.4). In Chapter 3, we first rederive the homogenisation result from [80] using a framework of periodic arrays of uptaking cylinders (hairs). Noticing that this framework can also be used to model nutrient or water uptake by a field of crops, we further study how well the homogenisation result compares with full-geometry numerics using various continuity equations and boundary conditions. In Chapter 4, we study the case where the radius of the root hair is much smaller than the inter-hair distance, which eventually leads us to a distinguished limit. In Chapter 5, we first establish that the framework from Chapters 3 and 4 is a suitable geometry for modelling nutrient uptake by root hairs, if the hair length is much smaller than the root radius. However, this is rarely the case. Therefore, we then investigate the effects of root surface curvature and hair length on the homogenised equation, and obtain a better approximation for the case where the hair length is comparable to the root radius. In the final two chapters, we introduce different complex problems relating to uptake by plants, and show how even simple multiscale techniques can provide us with useful insights into these problems. In Chapter 6, we show how to upscale nitrate uptake kinetics from a single transporter level to a root segment level, and then propose a model for nitrate uptake via low and high affinity transporters (see Section 6.1.2). Model predictions for the time of depletion, and a threshold nitrate concentration at which uptake ceases, are both in accordance with empirical values (Section 6.3.6). Finally, we demonstrate that under certain conditions, three-dimensional descriptions of the root system architecture are not necessary to estimate overall water and nitrate uptake, and that simple one-dimensional models can be used instead (Chapter 7).
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Shrivastava, Ishita. "Shallow water outfalls for brine disposal from desalination plants." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/121883.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2019Cataloged from PDF version of thesis.
Includes bibliographical references.
Submerged outfalls consisting of multiple, closely spaced jets are often used to discharge industrial effluents in coastal waterbodies. Examples of such effluents include heated water from thermal power plants, treated wastewater effluent from sewage treatment plants, and reject brine from desalination plants. At locations with shallow water depth, the interaction between adjacent jets is enhanced and can affect mixing. The mixing of submerged outfalls in shallow water is studied in this thesis with particular emphasis on discharge of dense treated brine from desalination plants. Treatment options for brine involve blending it with less saline effluents or its concentration, and can have significant effect on the design of outfall and its mixing. The effect of shallow water depth on dilution of submerged outfalls is determined first for quiescent conditions, and a unified theory is developed for single and multiple jets discharging in shallow water.
The effect of shallowness is shown to be characterized by a non-dimensional parameter, which depends on the receiving water depth and the effluent momentum and buoyancy fluxes. The effect of brine treatment processes, which affect both discharge momentum and buoyancy, on the dilution of various contaminants is determined next. The effect of brine treatment on outfall design is also explored, and optimum outfall design variables are calculated for a range of conditions. In the presence of a crossflow, the mixing dynamics of multiple port outfalls are quite different, and can give rise to complex jet interactions and even reversing flow close to the upstream jets. Laboratory experiments, in which discharge and ambient parameters are varied, have led to an improved empirical expression for dilution. In addition to the strength of crossflow, outfall length and spacing of jets are also found to significantly affect dilution.
A numerical model, capable of modeling the discharge of multiple jets in a crossflow, is developed and shows significant improvement over existing models.
by Ishita Shrivastava.
Ph. D.
Ph.D. Massachusetts Institute of Technology, Department of Civil and Environmental Engineering
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Young, Kevin Bradley. "Development of Operational Strategies to Minimize Bromate Formation in the Moorhead Water Treatment Plant." Thesis, North Dakota State University, 2014. https://hdl.handle.net/10365/27277.
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A recent study at the Moorhead water treatment plant (MWTP) determined that bromate formed during ozone disinfection and, at times, exceeded the maximum contaminant level (MCL) of 10 parts per billion (ppb) in the summer months. Operational data showed that bromate formation was directly related to raw water bromide concentration and control of the ozone system. This study was conducted with the purpose of developing and implementing operational strategies to minimize bromate formation in the MWTP. Several operational changes, including selection of source water based on bromide concentration and controlling ozone addition in a manner that reduces the ozone dose used to achieve disinfection, were implemented and were effective at minimizing bromate formation in the ozone chambers. The bromate concentration in the finished drinking water was significantly reduced and only a few samples contained greater than 10 ppb bromate.Moorhead Public Service
American Water Works Association
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Jackson, Patricia. "Assessment of water samples from the Cahaba River and Buck Creek for the presence of estrogenic compounds." Birmingham, Ala. : University of Alabama at Birmingham, 2010. https://www.mhsl.uab.edu/dt/2010m/jackson.pdf.
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Komacek, Thaddeus D., and Dorian S. Abbot. "EFFECT OF SURFACE-MANTLE WATER EXCHANGE PARAMETERIZATIONS ON EXOPLANET OCEAN DEPTHS." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/622455.
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Terrestrial exoplanets in the canonical habitable zone may have a variety of initial water fractions due to random volatile delivery by planetesimals. If the total planetary water complement is high, the entire surface may be covered in water, forming a "waterworld." On a planet with active tectonics, competing mechanisms act to regulate the abundance of water on the surface by determining the partitioning of water between interior and surface. Here we explore how the incorporation of different mechanisms for the degassing and regassing of water changes the volatile evolution of a planet. For all of the models considered, volatile cycling reaches an approximate steady state after similar to 2 Gyr. Using these steady. states, we find that if volatile cycling is either solely dependent on temperature or seafloor pressure, exoplanets require a high abundance (greater than or similar to 0.3% of total mass) of water to have fully inundated surfaces. However, if degassing is more dependent on seafloor pressure and regassing mainly dependent on mantle temperature, the degassing rate is relatively large at late times and a steady. state between degassing and regassing is reached with a substantial surface water fraction. If this hybrid model is physical, super-Earths with a total water fraction similar to that of the Earth can become waterworlds. As a result, further understanding of the processes that drive volatile cycling on terrestrial planets is needed to determine the water fraction at which they are likely to become waterworlds.
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Cortés, de la Fuente Christian. "Supervisory systems in waste water treatment plants: sistematise their implementation." Doctoral thesis, Universitat de Girona, 2002. http://hdl.handle.net/10803/7777.
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La implantació de Sistemes de Suport a la presa de Decisions (SSD) en Estacions Depuradores d'Aigües Residuals Urbanes (EDAR) facilita l'aplicació de tècniques més eficients basades en el coneixement per a la gestió del procés, assegurant la qualitat de l'aigua de sortida tot minimitzant el cost ambiental de la seva explotació. Els sistemes basats en el coneixement es caracteritzen per la seva capacitat de treballar amb dominis molt poc estructurats, i gran part de la informació rellevant de tipus qualitatiu i/o incerta. Precisament aquests són els trets característics que es poden trobar en els sistemes biològics de depuració, i en conseqüència en una EDAR. No obstant, l'elevada complexitat dels SSD fa molt costós el seu disseny, desenvolupament i aplicació en planta real, pel que resulta determinant la generació d'un protocol que faciliti la seva exportació a EDARs de tecnologia similar. L'objectiu del present treball de Tesi és precisament el desenvolupament d'un protocol que faciliti l'exportació sistemàtica de SSD i l'aprofitament del coneixement del procés prèviament adquirit. El treball es desenvolupa en base al cas d'estudi resultant de l'exportació a l'EDAR Montornès del prototipus original de SSD implementat a l'EDAR Granollers. Aquest SSD integra dos tipus de sistemes basats en el coneixement, concretament els sistemes basats en regles (els quals són programes informàtics que emulen el raonament humà i la seva capacitat de solucionar problemes utilitzant les mateixes fonts d'informació) i els sistemes de raonament basats en casos (els quals són programes informàtics basats en el coneixement que volen solucionar les situacions anormals que pateix la planta en el moment actual mitjançant el record de l'acció efectuada en una situació passada similar).
El treball està estructurat en diferents capítols, en el primer dels quals, el lector s'introdueix en el món dels sistemes de suport a la decisió i en el domini de la depuració d'aigües. Seguidament es fixen els objectius i es descriuen els materials i mètodes utilitzats. A continuació es presenta el prototipus de SSD desenvolupat per la EDAR Granollers. Una vegada el prototipus ha estat presentat es descriu el primer protocol plantejat pel mateix autor de la Tesi en el seu Treball de Recerca. A continuació es presenten els resultats obtinguts en l'aplicació pràctica del protocol per generar un nou SSD, per una planta depuradora diferent, partint del prototipus. L'aplicació pràctica del protocol permet l'evolució del mateix cap a un millor pla d'exportació.
Finalment, es pot concloure que el nou protocol redueix el temps necessari per realitzar el procés d'exportació, tot i que el nombre de passos necessaris ha augmentat, la qual cosa significa que el nou protocol és més sistemàtic.
The decision support systems (DSS) implemented in wastewater treatment plants (WWTP) make easier the application of better techniques based on the knowledge to manage the process, insuring the effluent quality and minimising the economical costs of its exploitation. The knowledge-based systems are characterised by its capability of working in ill structured domains, and with relevant information of type qualitative or uncertain. These are the characteristics that could be found in the biological systems treatments, and consequently in a wastewater treatment plant. However, the high complexity of the DSS makes very expensive their design, development and the application in a real WWTP, and because this reason it is very important the generation of a protocol that makes easier the exportation of the program to other similar plants.
The objective of the present document is the development of a protocol that makes easier the systematic exportation of DSS and the reuse of the process knowledge acquired previously. The document is developed in basis on the study case from the DSS exportation from the Granollers WWTP to Montornès WWTP. This knowledge-based system integrates two kinds of systems based on knowledge, concretely the rule-based systems (which are programs that simulate the human reasoning and its capability of problem solving using the same information sources) and the case-based reasoning systems (which are informatic programs based on knowledge that solve the current abnormal situations in the plant by means of retrieving the executed action in a similar past situation).
The document is structured in different chapters, in the first chapter; the lector is introduced in the DSS domain and in the wastewater treatment domain. Afterwards the objectives are defined and the materials and methods used are explained. Following, the Granollers DSS prototype is presented. Once, the prototype is explained, the first protocol made by the author in his research work is presented. Afterwards, the results obtained from the protocol application to export the DSS to other plant are presented. The real application of the protocol allows making better itself.
In conclusion, the new protocol reduces the needed time to make the exportation process, although the new protocol needs more steps to make the same work, this means that it is more systematic.
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Malan, Cheryl. "The efficiency of drinking water treatment plants in removing immunotoxins." Thesis, University of the Western Cape, 2010. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5762_1308732795.
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The aim of this study was to evaluate the effectiveness of water treatment processes of two drinking water plants to remove immunotoxins and steroid hormones. Raw and treated drinking water was screened for effects on inflammatory activity using the biomarker IL-6, humoral immunity using the biomarker IL-10 and cell mediated immunity using the biomarker IFN-&gamma
. In vitro human whole blood culture assays were used in order to elucidate potential immunotoxicity.
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Barros, JosivÃnia Rodrigues. "Irrigation yellow melon plants with saline water enriched with CO2." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14644.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoSalt excess in the soil solution is a serious problem in agriculture, caused mainly by irrigation water, causing soil salinization. These salts, when absorbed affects the growth of plants because of the osmotic effect, reducing the absorption of water in the soil. In order to mitigate the deleterious effects of these salts in plants, several strategies have been developed in order to make plants most tolerant to salt stress. A recent innovation in plant cultivation system is the enrichment of irrigation water with carbon dioxide (carbonation), influencing the commercial crop yield and making them more tolerant to stresses. The objective of this study was to evaluate whether the application of CO2 in irrigation water of melon plants increases the tolerance of the same to salt stress. The experiment was conducted in Pacajus Experimental Field of Embrapa Tropical Agroindustry. The treatments were arranged in a factorial 5 x 3 with four replications, referring to salt solutions at electrical conductivities of (ECw) (0.5, 1.5, 3.0, 4.5 and 6.0 dS m-1) and three treatments with CO2: no CO2 (SC), five applications of CO2 (since flowering until the beginning ripening of fruits) (C1) and two applications of CO2 (since fruit set until the ripening of fruits) (C2). The CO2 was used as a gas injected weekly directly in the irrigation system. The electrical conductivity of the soil saturation extract and CO2 content in the irrigation water were measured at the end of the experiment. The measurement of photosynthesis, stomatal conductance and transpiration occurred throughout plant development. Were also evaluated leaf area, dry weight of leaves and stem + branches, levels of Na+, Cl-, K+ and carbohydrates in the leaves and stems + branches, the number of fruits, productivity, weight, lengths and diameters of the fruit, pulp thickness, total soluble solids and citric acid content. Leaf concentrations of Na+, Cl- and K+ in the leaf and stem + branches were influenced by salinity, with interaction salinity x CO2. For the growth variables: leaf area, dry matter of leaves and stem + branches, there was a significant difference only for the salinity levels. All variables of gas exchange were influenced by salinity, while the stomatal conductance and net photosynthesis were significantly influenced by the application of CO2. The carbohydrate in stem + branches were influenced by the application of CO2. Irrigation with saline water caused a reduction in productivity, number of fruits, lengths of commercial and total fruits. These variables were not influenced by the application of CO2. It is concluded that salinity affected the growth, development and production of melon plants, while the application of CO2 did not minimize the deleterious effect of salts in plants.
Um dos grandes problemas enfrentados pela agricultura à o excesso de sais dissolvidos na soluÃÃo do solo, carreados principalmente pela Ãgua de irrigaÃÃo, causando a salinizaÃÃo do solo. Esses sais, ao serem absorvidos, afetam o crescimento das plantas devido ao efeito osmÃtico, dificultando a absorÃÃo de Ãgua no solo. A fim de amenizar os efeitos deletÃrios desses sais nas plantas, vÃrias estratÃgias vÃm sendo desenvolvidas visando tornar as plantas mais tolerantes ao estresse salino. Uma inovaÃÃo recente no sistema de cultivo de plantas à o enriquecimento da Ãgua de irrigaÃÃo com o diÃxido de carbono (carbonataÃÃo), influenciando a produtividade comercial da cultura e tornando-a mais tolerante a estresses. Assim, o objetivo deste trabalho foi avaliar se a aplicaÃÃo de CO2 na Ãgua de irrigaÃÃo de plantas de meloeiro aumenta a tolerÃncia das mesmas ao estresse salino. O experimento foi conduzido no Campo Experimental de Pacajus da Embrapa AgroindÃstria Tropical. Os tratamentos foram dispostos em esquema fatorial 5 x 3 com quatro repetiÃÃes, referentes Ãs soluÃÃes salinas com condutividades elÃtricas de (CEa) (0,5; 1,5; 3,0; 4,5 e 6,0 dS m-1) e trÃs tratamentos de CO2: ausÃncia de CO2 (SC), cinco aplicaÃÃes de CO2 (inÃcio do florescimento atà a maturaÃÃo dos frutos) (C1) e duas aplicaÃÃes de CO2 (apÃs a frutificaÃÃo atà a maturaÃÃo dos frutos) (C2). O CO2 foi aplicado na forma de gÃs, injetado semanalmente diretamente no sistema de irrigaÃÃo. A condutividade elÃtrica do extrato de saturaÃÃo do solo e o teor de CO2 na Ãgua de irrigaÃÃo foram mensurados ao final do experimento. As mediÃÃes de fotossÃntese, transpiraÃÃo e condutÃncia estomÃtica ocorreram ao longo do desenvolvimento das plantas. Foram avaliadas ainda a Ãrea foliar, as massas secas das folhas e do caule + ramos, os teores de Na+, Cl-, K+ e os carboidratos nas folhas e nos caules + ramos, o nÃmero de frutos, a produtividade de frutos, o peso, os comprimentos e diÃmetros dos frutos, espessura da polpa, sÃlidos solÃveis totais e teor de Ãcido cÃtrico. Os teores de Na+, Cl- e k+ na folha e caule + ramos foram influenciados pela salinidade, havendo interaÃÃo salinidade x CO2. Para as variÃveis de crescimento: Ãrea foliar, matÃria seca das folhas e caule +ramos, houve diferenÃa significativa apenas para os nÃveis de salinidade. Todas as variÃveis de trocas gasosas foram influenciadas pela salinidade, enquanto que a condutÃncia estomÃtica e a fotossÃntese liquida foram significativamente influenciadas pela aplicaÃÃo de CO2. Os teores de carboidratos no caule + ramos foram influenciados pela aplicaÃÃo de CO2. A irrigaÃÃo com Ãgua salina provocou reduÃÃo na produtividade, nÃmero de frutos, comprimentos dos frutos comercias e mÃdios. Essas variÃveis nÃo foram influenciadas pela aplicaÃÃo de CO2. Em funÃÃo do exposto, conclui-se que a salinidade afetou o crescimento, desenvolvimento e produÃÃo das plantas de meloeiro, enquanto a aplicaÃÃo do CO2 nÃo minimizou o efeito deletÃrio dos sais nas plantas.
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Obi, CL, MNB Momba, A. Samie, JO Igumbor, E. Green, and E. Musie. "Microbiological, physico-chemical and management parameters impinging on the efficiency of small water treatment plants in the Limpopo and Mpumalanga Provinces of South Africa." Water SA, 2007. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000861.
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In the wake of the growing dependence on small water treatment plants (SWTPs) in providing quality water to rural areas and the global burden of water borne diseases, this study sought to examine the efficiency of 55 SWTPs located in rural or peri-urban areas of Limpopo and Mpumalanga Provinces in order to gauge the safety of water supply for human consumption. The microbiological and physical parameters of raw water, treated water and water in the distribution systems were examined using standard methods. Management issues impacting on quality of water supply were determined by use of questionnaires and focus group discussions. Results obtained showed that the pH, turbidity, temperature and conductivity of the raw water in SWTPs studied in both provinces ranged between 6.46 to 9.05 pH units, 0.19 to 8.0 NTU, 15.4oC to 31.40oC and 44.40.4 μS to 108 μS respectively. Water quality compliance at point of use (treated water) according to the Department of Water Affairs and Forestry of South Africa guidelines in SWTPs studied in both provinces were 85% for faecal coliforms and 69% for total coliforms. In the distribution systems, TCCs, FCCs and HPCs were within recommended limits except for few SWTPs suggesting a possibility of inadequate treatment and this may represent post-treatment contamination and possible risk of infection from these water supply sources. Physical parameters were generally within the recommended ranges . In terms of administrative issues, some plant operators did not have adequate knowledge of the functioning of the SWTPs and most were unable to calculate chlorine dosage, determine flow rates or undertake repairs of basic equipment. Poor working conditions , frequent stock depletion of chemicals , lack of maintenance culture , lack of emergency preparedness and poor communication were also cited .
The study has revealed that the microbiological quality of raw water was very poor but that water treatment was efficient in the majority of SWTPs studied in both provinces. Regular monitoring of microbial and physico-chemical parameters of water quality served by the different SWTPs to the population is recommended to gauge their safety for human consumption. Issues such as enhanced incentives and periodic training of plant operators, improved communication and conditions of service , periodic stock inventory and entrenchment of maintenance culture may be necessary to ensure sustained and efficient water distribution systems.
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Todd, Malcolm John. "Development and characterisation of a WO3-based photoanode for application in a photoelectrocatalytic fuel cell." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=33583.
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Xie, Chao. "Singularities in the Unphysical Complex Plane for Deep Water Waves." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1250279425.
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Logie, Malcolme Ronald Ruxton. "Photosynthetic gas exchange responses to light, temperature, carbon dioxide and water stress, and changes in photosynthetic pigments to light and water stress in two cultivars of Hordeum vulgare L." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1003779.
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The gas exchange responses of two cultivars of Hordeum vulgare L., to light, temperature, CO₂ and water stress were investigated in the laboratory. The optimum temperature for net CO₂ assimilation was found to be 25°C and 22.5°C for cv. Clipper and cv. Dayan respectively. Net CO₂ assimilation was reduced at 30°C in cv. Dayan. At low light intensity the highest quantum yield efficiency was 0.051 mol.mol⁻¹ at 30°C for cv. Clipper, and 0.066 mol.mol⁻¹ at 20°C for cv. Dayan. At the same temperature, cv. Clipper had a higher water use efficiency than cv. Dayan, but stomatal conductance for cv. Dayan was higher than cv. Clipper. Stomatal limitation to CO₂ was lowest at the optimum temperature for CO₂ assimilation in both cultivars. Stomata limited CO₂ assimilation in cv. Clipper to a larger degree than in cv. Dayan. Relative stomatal limitation for cv. Clipper at 25°C was 0.280 ± 0.010, and for cv. Dayan at 22.5°C was 0.028 ± 0.011. Short-term exposure to elevated CO₂ concentrations increased CO₂ assimilation in both cultivars, but more so for cv. Clipper. Transpiration rate at elevated CO₂ partial pressures were higher in cv. Dayan than in cv. Clipper. At very high CO₂ (860 μmol.m⁻²s⁻¹) partial pressure water use efficiency in cv. Clipper was higher than cv. Dayan, but at low CO₂ partial pressures water use efficiency in cv. Dayan was higher than cv. Clipper. Water stress reduced the relative leaf water content and net CO₂ assimilation in both cultivars. Cultivar Dayan was more tolerant to water stress, and CO₂ assimilation in this cultivar was less affected by water stress. In both cultivars water stress increased the concentration of chlorophyll a, chlorophyll b, and chlorophyll a+b. The chlorophyll a:b ratio remained relatively constant throughout the stress period. No correlation between relative leaf water content and total carotenoid concentration was observed.
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Baker, Jeffrey Loy. "Health of fish impringed on cooling-water intake screens." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Theses/BAKER_JEFFREY_3.pdf.
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Rodell, Matthew. "Estimating changes in terrestrial water storage /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004367.
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Storlie, Leslee. "An Investigation into Bromate Formation in Ozone Disinfection Systems." Thesis, North Dakota State University, 2013. https://hdl.handle.net/10365/26896.
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Ozonation is used as an alternative disinfection process to chlorination but unfortunately has a potential of oxidizing bromide, a natural component of water sources, to bromate. Bromate is a possible carcinogen with a maximum contaminant level of 10 ppb. To understand bromate formation in full-scale systems, a comprehensive study was conducted at the Moorhead Water Treatment Plant (WTP). Bromide concentrations in source waters were monitored. Water samples from locations in the ozonation chambers were collected and analyzed for bromate and other parameters. Results showed that bromate formation was increased through increases in pH, bromide, and ozone dose during high temperatures and was decreased by increases in organics. The impact of the bromate influential parameters was minimized at low temperatures. To assist Moorhead WTP on developing bromate control strategies, a modeling approach was adopted to predict bromate formation at various operational conditions using temperature, pH, ozone dose, bromide, and TOC.MWH Global, AWWA Scholarship
American Water Works Association (AWWA), Minnesota and North Dakota sections
North Dakota Water Resources Research Institute
Department of Civil Engineering, North Dakota State University
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Pennington, Karrie Sellers 1949. "Alfalfa water-production functions under conditions of deficit irrigation with saline water." Diss., The University of Arizona, 1986. http://hdl.handle.net/10150/191117.
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This experiment was designed to determine the shape of the yield response function relating crop yield to total amount of saline irrigation water applied. Such a function contains a built-in leaching fraction that is the inevitable consequence of the inability of the plant to extract 100 % of the water from a saline soil. In order to define the production function and to determine the leaching fractions, alfalfa (Medicago sativa L. cv. 'Mesa Sirsa') was planted in soil columns in a greenhouse. Two experiments were run sequentially. These were irrigated with water of differing salinities. The first with an EC of 4 dS/m (1.4 bars) and the second with an EC of 8 dS/m (2.9 bars). Both solutions were prepared by adding equivalent amounts of sodium chloride and calcium chloride to distilled water. The treatment variables were amounts of irrigation water applied. The amounts in both experiments were 110%, 100%, 75%, 50% and 25% of the measured evapotranspiration (ET). Four crop harvests were made in each experiment. At the end of experiment 1, (approximately 120 days), one column from each treatment was destructively sampled for soil salinity and water content measurements. The remaining columns were similarly sampled at the end of experiment 2 (approximately 120 days). The crop-saline water production functions for both experiments were linear. Leaching fractions in experiment 1 were 9, 9, 6, 5 and 5% for treatments 1-5 respectively. Experiment 2 leaching fractions for treatments 1-5 respectively were 23, 25, 18, 15 and 17%. The lowest rootzone soil water osmotic potentials achieved by the end of experiment 1 for treatments 1-5 were -19, -20, -18, -26 and -24 bars. Corresponding treatment values achieved by the end of experiment 2 were -18, -22, -28, -31 and -45 bars.
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Alessi, Alison Ann 1974. "Transitory places : a water terminal and immigration station for East Boston." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8603.
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Thesis (M.Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 2001.Includes bibliographical references (p. 123-127).
An experience of the water in the city is often absent today as the urban has increasingly infringed on natural environments creating a distinct separation between the two. This thesis is an architectural exploration of the transition from land and water and from water to land in the contemporary city. Using architectural space to heighten the experience of water in the city, the design intervention aspires to reconnect people with the natural aquatic conditions that surround Boston but are removed from the everyday experience of the city. East Boston's waterfront provides a unique opportunity for development with strong visual connections to downtown Boston as well as powerful traces of a vibrant history, particularly that of immigration. East Boston was second only to Ellis Island in the volume of immigrants processed as they entered the United States. The design has a transient space, a water terminal that will both facilitate movement to and from the city as well as recall the historical memory and experience of arrival by water. The focus of the design has been the archival library in which one can engage one's own personal identity and heritage on the very site where, potentially, one's ancestors arrived one hundred years ago. Genealogical research can be conducted in the dynamic spaces above the water so that there is a possibility of overlapping past and present experiences as well as connecting people around the world via modern technologies. The library addresses the modern American identity while remembering the historical threshold to a new world that was located along the waterfront of East Boston.
by Alison Ann Alessi.
M.Arch.
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Shah, Jignesh. "Water consumption for steam methane reforming hydrogen plants in Edmonton, Canada." Thesis, Villanova University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10116994.
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Traditional engineering and financial assessments are limited not only to consideration of currently internalized costs, but also often lack consideration of new or current externalities during the life of the new system. The goal of this thesis is to provide a methodology that integrates sustainability assessment with the traditional assessments, thereby allowing the assessment and optimization of the total overall costs. The proposed method is applied for the steam methane reforming (SMR) plants operated by Air Products in Edmonton, Canada where the boiler feed water for hydrogen manufacturing is produced using the polished effluent from the local municipal wastewater treatment plant. The softening of the feed water to Reverse Osmosis (RO) system is proposed (after evaluating the several options) to improve the recovery for the current RO system from 75% to 95%. The overall costs were estimated for comparison of the current and proposed systems.
The production of hydrogen via SMR highlights the complexities of the sustainability assessment. While hydrogen may be considered a renewable transportation fuel, depending on whether the fossil natural gas can be replaced with renewable biogas or via electrolysis of water using renewable energy, it is reliant on the availability of water. However, water is a scarce resource that is also essential for basic human survival and ecological needs. As the population of the world increases, alternative water sources need to be explored, which may require more energy in the processing of such water to potable grade.
The results show that the proposed RO feed softening via Ion Exchange (IX) can improve RO recovery up to 95%. The financial assessments based on literature prices and cost factors show that the current operating cost can be reduced up to ~20% by improving RO recovery to 95% with ~75% probability for cost reduction at 95% recovery. When the capital costs are accounted for, NPV-based analyses show that for 95% recovery more than 20% IRR (if spare vessels are available for refurbishment) could be achieved.
Environmental assessments (Life Cycle Assessment method using SimaPro v7.3 following ISO 14040-44 standards) show that 1.12 x 10-3 ReCiPe Endpoints impact for current RO operation at 75% recovery can be reduced by ~8% when 95% RO recovery is achieved via the proposed system. Due to the need for increased NaCl salt for regeneration of resins in the proposed system, the environmental impacts increased for metal depletion and ionizing radiation impact categories, unlike the other impact categories. The GHG emissions could be reduced by ~10% (after accounting for 10%-30% probability) for 95% RO recovery with the reduction from the reduced consumption of inputs. Similarly, the life cycle water depletion impacts can be reduced by ~10% (after accounting for 30%-65% reduction probability) from the current 1.75kg water depletion per kg of BFW produced. Water Footprint Assessment (WFA) as per the Ridoutt & Pfister method shows that when accounted for local water stress, during the worst month, the blue water footprint increases from 1.75kg/kg BFW to 63.9kg/kg BFW, in addition to ~0.08kg/kg BFW greywater footprint.
The social assessment shows mixed results with lower employment, employee development, corporate philanthropy, environmental "protect" spend and R&D spend due to reduced overall consumptions for the 95% recovery option. The other social impact categories were improved for 95% recovery. The overall cost (estimated as the sum of the internally normalized social costs) were 3.0 units with up to 35% reduction potential.
The results of the case study show that IX feed softening has potential to not only reduce the environmental and social costs, but also meet the financial constraints. Also, this highlights that an integrated sustainability assessment method that evaluates and combines all three aspects of sustainability - environment, social and economic - could be developed. The proposed method as presented needs further development. Among other things, the lack of availability of robust social inventory database significantly hinders the development and adoption such integrated methods. The application of the method to additional case studies would be a good next step.
This exercise has highlighted that the value and benefits of overall cost estimates are beyond those of policy making by the regulatory agencies. Sustainability minded companies could benefit from having environmental and social goals along with the financial targets as they understand the risks from inadequate performances in any of these aspects. However, these goals are typically on a gate-to-gate basis and independent of each other; thereby, creating the potential for shifting burdens in the value chain and not obtaining the full benefits of risk mitigation. The assessment using the overall cost approach at life cycle basis is essential for industry in not only risk mitigation, but also opportunity identification at an early stage.
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Wiking, Viktoria. "A study of naturally occurring radon in Swedish water purification plants." Thesis, KTH, Mark- och vattenteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-199216.
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Radon dissolved in drinking-water can be transferred into the indoor air and is one of the main transfer pathways for radon. At water purification plants, large quantities of water are treated and there is a risk that radon degasses from the water and enters into the indoor air. Hence, there is a risk for elevated radon levels in the indoor air at these facilities. This study aims to investigate the general impact of water treatment processes on the radon concentration in water and its transfer into the indoor air. Moreover, the risk that radon exposure exceeds the regulatory limits at workplaces was investigated. In total, the results from 39 Swedish water purification plants are included in the study. The methodology includes long-term air measurements with alpha track detectors, and short-term air measurements with AlphaGUARDs. In addition, water samples were collected in order to analyze the radon concentration in the untreated and treated water. The results show that several plants experience elevated radon levels in the indoor air and in some cases the exposure could be problematic. Several connections were investigated without finding apparent connections for those cases. For example, the relation between radon concentration in the water and radon level in the indoor air was investigated and the connection between the volume of water treated and the radon level in the indoor air. Calculations with transfer coefficients indicate that the transfer of radon into the indoor air is relatively small. However, there can also be contribution from other radon transfer pathways, such as soil and buildings, which may have an impact on the radon levels in the indoor air.
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Karwa, Nitin. "Experimental Study of Water Jet Impingement Cooling of Hot Steel Plates." Phd thesis, tuprints, 2012. https://tuprints.ulb.tu-darmstadt.de/3041/1/PhD_Thesis_Karwa.pdf.
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Liquid jet impingement cooling is critical in many industrial applications. Principle applications include extracting large heat flux from metal parts, such as hot fuel bundle post-loss-of-coolant-accident in nuclear reactors, heat treatment of steel plates post-hot-processing, etc. The ability of liquid jets to extract high heat flux at controlled rates from metal parts, with temperatures as high as 800-1000 ºC, at moderate flow rates has made them indispensable in these applications. Due to the complexity of the process, the mechanism of flow boiling heat transfer during jet impingement cooling is not well understood. Resultantly, the presently used design approaches are based more on experience and rule of thumb than science. The principle challenge in the study of jet impingement cooling for these high temperature applications has been the lack of reliable instrumentation for measuring the cooling rates. To add to this, the conjugate nature of boiling heat transfer, especially on low conductivity metal like steel, makes this problem very complicated to understand. Thus, much of the state of art on this subject has been limited to experiments where either the conjugate problem has not been addressed or the tests have been performed at temperatures that are much lower than in the above mentioned applications.
The basic objective of the present work is to contribute to the understanding of the thermo-hydrodynamic phenomenon occurring during the cooling of a hot steel plate with an impinging water jet. This work also complements a parallel study being conducted at the Institute of Fluid Mechanics and Aerodynamics (Technische Universität Darmstadt), in which the complex transport processes are being treated theoretically and validated against the experimental results of this work.
To achieve the objective, transient cooling experiments have been performed on an instrumented stainless steel AISI-type 314 cylinder. To measure the temperature variation within the stainless steel cylinder during the transient cooling, fast-response thermocouples have been embedded within holes that are precisely drilled though its bottom flat face. The cylinder is induction heated to a homogeneous initial temperature of 900 ºC and is subsequently cooled by means of an axisymmetric subcooled free-surface water jet that impinges on its top flat face (impingement surface). During the cooling, each thermocouple output has been recorded at the rate of 100 samples per second. A two-dimensional axisymmetric inverse heat conduction analysis using these measured temperature data has been performed to estimate the temporospatial variation of temperature and heat flux on the impingement face. Both low and high speed images have been recorded to visualize the two-phase flow. These images and the estimated heat transfer distribution are used to understand the boiling mechanism. The effect of jet parameters, namely subcooling and impingement velocity, on the heat transfer process has been studied. Additionally, the effect of spent liquid accumulation over the impingement surface has been studied in few exploratory plunging jet experiments.
This study presents a systematic methodology for the measurement and estimation of the temporospatial variation of heat transfer on the impingement surface of a hot steel plate. Three distinct regions, with difference in the extent of liquid-wall contact, have been identified on the impingement surface from the recorded images.
i) A wetted region surrounds the jet stagnation region. Nucleate boiling is the principle heat transfer mode in this region. The outer periphery of this region is called the wetting front. No boiling activity has been observed in the high speed images, most likely because the bubbles were small and were unable to reach the liquid free-surface. The maximum heat flux position is determined to be within this region. As the wetted region grows in size with time, the maximum heat flux position also moves radially outwards. The wetting front and maximum heat flux position velocity reduce with increasing radial distance from the impingement point because the liquid velocity and subcooling reduce at the wetting front. Likewise, the wetting front velocity increases with jet velocity and subcooling.
ii) The liquid gets deflected at the wetting front due to the efflux of large vapor bubbles beyond the maximum heat flux position. A term ``wetting front region' has been coined in this thesis to describe this region. The width of this region could not be determined from the high speed images. Transition boiling within a thin superheated liquid film that is continuously replenished by the bulk flow is proposed to be the probable reason for the high heat flux in this region. Further, the radial heat conduction to the wetted region is also significant here.
iii) The impingement surface outside the wetting front region is dry. The dry surface slowly cools down due to film boiling and radial heat conduction to the wetting front region. The film boiling rate is very low in the impingement region. After deflecting away from the impingement surface in the wetting front region, the liquid film breaks into droplets over this region. Looking from the side, droplet deflection angle is observed to be small; still these droplets do not come into direct contact with the impingement surface, as has been confirmed by looking down from the top.
The velocity of the splashed droplets has been determined by analyzing the high speed images. It has been found that the drop velocity is much lower than the liquid film velocity calculated at the wetting front position using single-phase flow relations suggested by Watson. It has been hypothesized that the liquid film in the wetted region is decelerated by the bubbles growing on the impingement surface. Further, measurements reveal that the drop velocity increases with decreasing subcooling, which means that the film and the droplet are accelerated in the radial outward direction by the vapor released in the wetting front region.
It has been shown that the rewetting temperature (analogous to the Leidenfrost temperature for a sessile droplet), which refers here to the temperature below which the direct liquid-wall contact is re-established and the heat flux increases, in both the impingement and radial flow regions is significantly higher than that reported in the literature for pool boiling. Removal of bubbles by the flowing liquid in the early stages of their growth and then their rapid condensation within the subcooled liquid avoids the buildup of vapor near the hot wall, which is the likely reason for the enhancement of the rewetting temperature. This observation confirms that high heat fluxes can be removed at large wall superheats by impinging liquid jets, as practiced in the industry.
The boiling curve shifts to higher heat flux and superheat with the increase in the jet velocity and subcooling. The maximum heat flux and surface temperature at maximum heat flux increase with both the jet velocity and subcooling. Area-weighted average boiling curves have been determined, which clearly show the enhancement in the heat transfer with jet velocity over the average surface superheat of 100 to 800 K. The enhancement in jet subcooling is, however, noticeable only in the wall superheat range of 300 to 700 K. The maximum heat flux and surface temperature at maximum heat flux decrease with radial distance from the stagnation point before reaching a constant value. The radial distribution of maximum heat flux condition has been classified into three regions based on the relative size of the hydrodynamic/thermal boundary layer and the liquid film.
In the plunging jet impingement studies, it has been found that the wetting front growth slightly slows down due to accumulation of the spent liquid over the impingement surface. Area-weighted average boiling curves show that the heat transfer reduces due to accumulation.
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Dulin, Betsy Ennis. "Relating treatment process decisions to sludge management concerns at water plants." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/101273.
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In this study, the effects of organics removal efficiency, oxidant dose, and alum dose on aluminum hydroxide sludge characteristics were assessed. In order to maintain control over operating parameters, a continuous-flow laboratory-scale plant was operated in the laboratory with daily monitoring of pH, as well as influent and effluent turbidity, total organic carbon, and color.
Sludge thickening and dewatering characteristics were found to worsen when increasing amounts of organic matter were incorporated into the sludge floe matrix. Sludge properties improved with increases in oxidant dose and decreases in alum dose and alum/influent turbidity ratio. Changes in coagulation mechanism from sweep to charge neutralization were hypothesized to be partially responsible for changes in sludge properties caused by changing alum dose. Improvements in thickening and dewatering characteristics were found to be heavily dependent upon increases in sludge floe density, as well as decreases in aggregate water content.M.S.
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Banzatti, A., K. M. Pontoppidan, C. Salyk, G. J. Herczeg, Dishoeck E. F. van, and G. A. Blake. "THE DEPLETION OF WATER DURING DISPERSAL OF PLANET-FORMING DISK REGIONS." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/623096.
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We present a new velocity-resolved survey of 2.9 mu m spectra of hot H2O and OH gas emission from protoplanetary disks, obtained with the Cryogenic Infrared Echelle Spectrometer at the VLT (R similar to 96,000). With the addition of archival Spitzer-IRS spectra, this is the most comprehensive spectral data set of water vapor emission from disks ever assembled. We provide line fluxes at 2.9-33 mu m that probe from the dust sublimation radius at similar to 0.05 au out to the region of the water snow line. With a combined data set for 55 disks, we find a new correlation between H2O line fluxes and the radius of CO gas emission, as measured in velocity-resolved 4.7 mu m spectra (R-co), which probes molecular gaps in inner disks. We find that H2O emission disappears from 2.9 mu m (hotter water) to 33 mu m (colder water) as R-co increases and expands out to the snow line radius. These results suggest that the infrared water spectrum is a tracer of inside-out water depletion within the snow line. It also helps clarify an unsolved discrepancy between water observations and models by finding that disks around stars of M-star > 1.5M(circle dot) generally have inner gaps with depleted molecular gas content. We measure radial trends in H2O, OH, and CO line fluxes that can be used as benchmarks for models to study the chemical composition and evolution of planet-forming disk regions at 0.05-20 au. We propose that JWST spectroscopy of molecular-gas may be used as a probe of inner disk gas depletion, complementary to the larger gaps and holes detected by direct imaging and by ALMA.
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Hill, Catherine. "Collisional and structural properties of water ice in planet-forming regions." Thesis, Open University, 2015. http://oro.open.ac.uk/45248/.
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With the number of detected exoplanets standing at close to 2000, it seems that planets are ubiquitous throughout the universe. However, the processes leading to their formation are not well understood. It is widely accepted that planets form by dust aggregation from the material of protoplanetary disks, with micron-sized particles sticking together by van der Waals forces and kilometre-sized particles sticking together due to gravity. The process of growth between millimetre and kilometre sizes is yet to be explained, despite decades of research studying the collisions of silicate dust particles which form the main component of protoplanetary dust. However, the water ice that is present in the outer regions of protoplanetary disks has so far received less consideration. In this thesis, the collisional and structural properties of ices analogous to those in planet-forming regions were studied experimentally. Low velocity collisions of millimetre and centimetre-sized crystalline ice particles (both pure water and ice composed of pure water and water containing 5% methanol or formic acid) were investigated using a dedicated experimental set up for use on board parabolic flights. The porosity and pore collapse of amorphous solid water (ASW) grown at a variety of temperatures was investigated using neutron scattering. The results presented in this thesis show that crystalline water ice particles do not stick at relevant collision velocities, casting doubt on their ability to enhance planet formation by particle adhesion. However, the results of the neutron scattering experiments suggest that ASW is likely to remain porous at temperatures below 121 K, which may increase the likelihood of particle sticking. Sticking may also be enhanced by ice restructuring during pore collapse. The results of the experiments growing ASW at temperatures below 77 K show that these ices have different porosities, but further work is needed to fully characterise this.
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Tasana, Nomalanga Gloria. "Optimisation and evaluation of boron analysis for pressurized Water reactor plants." Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2328.
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Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2016.Boron concentration analysis is an important and critical analysis performed by the Analytical Chemistry Laboratory at Koeberg Nuclear Power Station (KNPS), because boron controls reactivity and the concentration determination is a Technical Specification Parameter (safety parameter). Hence accurate, precise results for boron concentration produced by laboratories and on-line analysers are important because of their operational implications associated with reactivity control and also for nuclear safety. The project focused on comparing the quality of chemical analysis results of boron produced by analysis techniques/ methods used at Koeberg Nuclear Power Station namely; Potentiometric Titration, Atomic Absorption Spectrophotometry (Flame) and UV-VIS Azomethine-H method. The methods were described, optimised, evaluated and compared in terms of uncertainty of measurement, accuracy, precision, analysis range, limitations, appropriateness and applicability for boron analysis in 2500 mg B/kg concentration range. For Potentiometric Titration method, the measurement uncertainty = 2500 ±16 mg B/kg, accuracy= 0.2%, precision= 0.08% the range of analysis= 5-800 mg B/kg. For Atomic Absorption Spectrophotometry (Flame) the measurement uncertainty= 2500 ±51 mg B/kg, accuracy= 0.12%, precision= 0.44% the range of analysis= 0 -500 mg B/kg. For UV-VIS Azomethine-H the measurement uncertainty= 2500 ±72 mg B/kg, accuracy= 0.08%, precision= 0.44% the range of analysis= 0 -10 mg B/kg. The INPOs 95% accuracy and precision criteria for boron is ± 1%. So these techniques could be used for boron analysis in PWR. Based on the evaluation and assessments mentioned above; the Potentiometric Titration was found to be the most preferred method for boron analysis for Pressurised Water Reactors followed by Atomic Absorption Spectrophotometry (Flame) that can be of good use in determining boron especially in waste samples and samples with complex matrices. The UV-VIS Azomethine-H methods can only be used when it is really necessary to determine very low levels of boron between 0- 10mg B/kg of which it was never required before. Since it is specifically the B-10 isotope that is responsible for the ability to control reactivity, the implementation of isotopic boron analysis (by Inductively Coupled Plasma – Mass Spectrometry) at KNPS is explained and the advantage of the programme is illustrated. Although the current state of instrumental capabilities is adequate for 10B isotope determination, further work of optimising the methodology for even better results is recommended.
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Fraser, Justin. "Surface tension driven water pumping : a bio inspired passive water pump." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97105.
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Thesis (MEng)--Stellenbosch University, 2015.ENGLISH ABSTRACT: The purpose of this study is to construct and test a surface tension driven water pump. The surface tension driven water pump is a passive water pump which uses a similar mechanism to that of trees to pump water. This study was conducted at the Department of Mechanical and Mechatronic Engineering at the University of Stellenbosch. For the study an extensive literature survey was done encompassing aspects such as water properties, surface tension (basic principles, capillary forces, temperature and contaminant effects, wettability), bubble formation (nucleation theory and tensile strength of water) and, finally water and mineral transport in trees (plant structures and mechanisms, limiting factors, misconceptions and organic substance transport). Previous work by botanists who demonstrate the transpiration mechanism needed for water transport in trees was also considered. The study further required the development of a theoretical thermal-hydraulic model to simulate the pumping performance for the surface tension driven water pump. The developed water pump was also experimentally tested with particular focus on design improvement, pumping performance, pump behaviour, potential pumping head as well as water collection capability. The experimental data was statistically analysed by multi-linear regression. Both the experimental data and statically generated predictions were compared to the theoretical thermal-hydraulic model. The results show that a working surface tension driven pump was constructed. Evaporation rates of up to 400 mL/hr.m2 were obtained, with pumping head heights reaching up to 1.8 m and a maximum pump functional lifespan of 13 days. The results further suggest that there is a good correlation between the various statistical fits and the experimental data. The developed theoretical thermal-hydraulic model was also found to be in good agreement with the experimental results. A sensitivity analysis of the theoretical and statistical models showed that the statistical models fairs poorly under extrapolation. Additionally, the mechanistic causes of pump failure as well as the effect of heat and pumping head on water pumping performance were identified. Thereafter, the water collection efficiency was established to be 98% on average. Further testing revealed that the pumping performance of larger area or multiple grouped “leaves” are less accurately predicted with the theoretical model than a single “leaf”. In conclusion, the results provide some support that the surface tension driven pump may be used as a water transport system in an artificial photosynthesis project, if the functional lifespan of the pump can be greatly improved. It is recommended that a more rigid hydrophilic material be used in the “leaf” interface and that multiple narrower conduits be used instead of a single larger pipe. Additional future work may include the development of pit-like structures to prevent air spreading throughout the system as well as a simple mechanism for evaporative control.
AFRIKAANSE OPSOMMING: Die doel van hierdie ondersoek is om 'n oppervlakspanning-aangedrewe waterpomp te bou en te toets. Die oppervlakspanning-aangedrewe waterpomp is ‘n passiewe waterpomp wat gebruik maak van ‘n meganisme soortgelyke aan dié van bome om water te pomp. Hierdie ondersoek is by die Departement Meganiese en Megatroniese Ingenieurswese by die Universiteit van Stellenbosch uitgevoer. Vir die ondersoek is 'n uitgebreide literatuurstudie gedoen wat aspekte soos water eienskappe, oppervlakspanning (basiese beginsels, kapillêre kragte, die uitwerking van temperatuur, onsuiwerhede asook benatbaarheid), lugborrelvorming (kernvormingsteorie en die treksterkte van water) en uiteindelik water- en mineraalvervoer in bome (plantstrukture en -meganismes, beperkende faktore, wanpersepsies en die vervoer van organiese stowwe) insluit. Vorige navoring deur plantkundiges, wat die watervervoermeganismes in bome demonstreer, is ook in ag geneem. Die ondersoek het die ontwikkeling van 'n teoretiese termies-hidrouliese model ingesluit, wat gebruik is om die oppervlakspanning-aangedrewe waterpomp se werking te voorspel. Die waterpomp is ook eksperimenteel getoets met die fokus op ontwerpverbetering, pompwerkverrigting, pompwerking, potensiële pompopvoerdrukhoogte sowel as die waterversamelingsvermoë. Die eksperimentele data is statisties ontleed deur middel van meervoudige liniêre regressie. Beide die eksperimentele data en statisties-gegenereerde voorspellings is vergelyk met die teoretiese termies-hidrouliese-model. Die resultate toon dat 'n werkende oppervlakspanning-aangedrewe pomp gebou is. ‘n Verdampingstempo van tot 400 mL/hr.m2, pompopvoerdrukhoogte van tot 1.8m en 'n maksimum funksionele pompleeftyd van 13 dae is bereik. Die resultate dui verder daarop dat daar 'n goeie korrelasie tussen die verskillende statistiese lynpassings en die eksperimentele data is. Die teoretiese termies-hidrouliese-model wat ontwikkel is, toon 'n goeie ooreenkoms met die eksperimentele resultate. 'n Sensitiwiteitsanalise van die teoretiese en statistiese modelle het getoon dat die statistiese modelle swak voorspellings maak as geëkstrapoleerde data gebruik word. Verder is die meganismes wat pompweiering veroorsaak, die effek van hitte asook die effek van pompopvoerdrukhoogte op die pomp se werkverrigting geïdentifiseer. Daarna is die doeltreffendheid van waterversamelingsvermoë vir die waterpomp vasgestel op gemiddeld 98%. Verdere toetse het getoon dat die pompwerkverrigting van groter gegroepeerde "blare" minder akkuraat met die teoretiese model voorspel word as vir 'n enkele "blaar". Ten slotte: Die resultate toon dat die oppervlakspanning-aangedrewe waterpomp as 'n water vervoer stelsel gebruik kan word in 'n kunsmatige fotosinteseprojek, indien die funksionele leeftyd van die pomp verbeter kan word. Dit word aanbeveel dat 'n sterker hidrofiliese materiaal in die "blaar"-koppelvlak gebruik word en dat verskeie nouer leipype gebruik word in plaas van 'n enkele groter pyp. Bykomende toekomstige werk kan die ontwikkeling van put-agtige strukture insluit wat die verspeiding van lug deur die hele stelsel voorkom, sowel as 'n eenvoudige meganisme wat die verdampingstempo beheer.
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Dale, Cari K. "Achieving effective asset management for water and wastewater utilities: A comparison of policy options for a special district and a medium city." CSUSB ScholarWorks, 2005. https://scholarworks.lib.csusb.edu/etd-project/2812.
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This project developed a model for effective asset management drawn from successful programs in the United States, Australia, and New Zealand. Asset management practices were examined at the City of Ontario Utilities Department; a medium sized utility, and also at the Rainbow Municipal Water District, a small sized utility. Gaps between the ideal model and the existing practices were investigated.
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Raymond, Sean Neylon. "Late-stage accretion and habitability of terrestrial planets /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/5438.
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Wong, Yuen-wah, and 黃婉華. "Performance prediction model for a solar water pump." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31223722.
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Wong, Yuen-wah. "Performance prediction model for a solar water pump /." Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21607424.
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Shepard, Dawn Joy. "Modeling water temperature in small agricultural drainage watercourses." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Summer2005/D%5FShepard%5F061505.pdf.
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Omar, Yahya Yussuf. "Risk management for drinking water supplies in developing countries : the influence of culture on water safety plans." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8564.
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Consumption of unsafe water in developing countries results in considerable number of illnesses and deaths annually. The World Health Organization and the International Water Association are promoting the use of water safety plans (WSPs), a risk management approach aimed at attaining water safety. This study investigated how culture impacts on the implementation of WSPs in these countries. Combining interpretive and critical paradigms resulted in the choice of qualitative methodologies utilizing multiple-case studies. Cases from India, Uganda, and Jamaica are each embedded with three units of analysis: promoters of WSPs, water utilities and their customers. Thematic analysis of data generated from semi-structured interviews, field observations and documents revealed eleven cultural factors impacting on the implementation of WSPs. Analyses of these factors led to various groupings and the subsequent development of a taxonomy categorizing these factors as being either enabling, limiting, or neutral in relation to WSPs. Findings show all the limiting factors to be deviations from the values and principles on which they are built. The findings have also led to the development of a culturally adapted risk management framework. This four-step cyclical & iterative framework is designed to address the impact of culture on the implementation of WSPs. The implementation of WSPs will take time and will require continuous improvement to the process. The successful management of drinking water risks in developing countries will require a broad institutional approach and a concerted effort that involves institutions beyond the water utilities. As such, targeted recommendations are first made towards achievement of good governance. Activities that will lead to the embracement of WSP by stakeholders along with suggestions to attain its institutionalization are also put forward. Recommendations towards addressing negative cultural factors include suggestions on dealing with: pollution causing rituals, bettering storage related practices, addressing excessive water use in rituals, counteracting belief that water should be free, fighting corruption and improving compliance, changing deliver-first safety-later attitude, and improving knowledge management practices.
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Gang, Dianchen. "Modeling of THM and HAA formation in Missouri waters upon chlorination /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3025619.
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Jack, Andrew G. "Total emission analysis of sewerage systems and wastewater treatment plants." Thesis, Abertay University, 1999. https://rke.abertay.ac.uk/en/studentTheses/3a4ee741-9f14-47df-ab48-2759ca7c39f3.
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The proposed methodology to most effectively manage intermittent combined sewage discharges into urban watercourses in the UK is given in the Urban Pollution Management (UPM) manual. The method is based on the use of detailed computer models of the sewerage system, wastewater treatment plant and receiving watercourse. Solving intermittent discharge problems using UPM, often requires the installation of in-sewer storage tanks. However, recent research from Germany and elsewhere (e.g. Austria and Denmark) has shown that this type of solution may be of little benefit with respect to the total emissions discharged from the entire system, where emissions from both the Combined Sewer Overflows (CSOs) and the Wastewater Treatment Plant (WTP) are considered together. This is because, in certain situations, WTP efficiency can be compromised by the prolonged periods of dilute (low nutrients and substrate) inflows which can result from the draining down of in-sewer storage tanks. The earlier research in Germany and elsewhere has been concerned with long term total emissions (annual loads) and not the problems specific to individual sites, or the benefits and/or limitations of storage with respect to acute pollution. Thus the principal objective of the research described here has been to substantiate and quantify the total emission problem by means of detailed modelling, via an evaluation of the likely storage volumes which could give rise to total emissions problems for the Perth wastewater system. Following this, a general method has been developed to investigate and resolve total emission problems related to acute pollution effects. As WTP disruption due to flow dilution can last for a prolonged period after even a single rainfall event, computational simulation times need to be long enough to represent the delay in WTP performance returning to normal operating conditions. As long term continuous simulation is usually impractical due to protracted computational times, a method referred to as the Total Emission Analysis Period (TEAP) has been developed. This will define the minimum required computational time and rainfall inputs to be used to ensure that the effect of in-sewer storage on total emissions could be modelled. Utilising the TEAP method to analyse total emissions it has been concluded that increasing volumes of storage would not be expected to create a total emission XXVI problem with respect to the Biochemical Oxygen Demand (BOD). Consequently, it was concluded that the best storage volume with respect to BOD was the minimum volume which would allow compliance with receiving water quality standards. No direct comparison could be made with the conclusion derived from the German research due to the long term nature of their analysis, however, it would appear from an interpretation of their results, that similar findings were obtained. With respect to ammonia, it was found that increases in total emissions can occur as, ammonia concentrations, unlike BOD, do not increase at the start of a storm due to first foul flush effects. Consequently, any increased emissions from the WTP would not be offset via a reduced CSO spill load. It was also found, however, that increasing volumes of storage would not be expected to exacerbate acute pollution problems within a receiving watercourse and that both large and small storage volumes had the potential to give rise to very similar degrees of WTP disruption. This was due to the way in which different hydraulic loading conditions (caused by the different volumes of storage) affected the bacterial concentrations in the reactor. The conclusion that storage would not provide a significant benefit for ammonia total emissions was supported by the Austrian and Danish research.
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Sosa, Pieroni Jhosmar L. "Estimation of water footprints and review of water-saving/recovery approaches in coal-fired power plants' cooling systems." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367938141.
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Caraballo, Ginna. "An Arduino Based Control System for a Brackish Water Desalination Plant." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc804931/.
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Water scarcity for agriculture is one of the most important challenges to improve food security worldwide. In this thesis we study the potential to develop a low-cost controller for a small scale brackish desalination plant that consists of proven water treatment technologies, reverse osmosis, cation exchange, and nanofiltration to treat groundwater into two final products: drinking water and irrigation water. The plant is powered by a combination of wind and solar power systems. The low-cost controller uses Arduino Mega, and Arduino DUE, which consist of ATmega2560 and Atmel SAM3X8E ARM Cortex-M3 CPU microcontrollers. These are widely used systems characterized for good performance and low cost. However, Arduino also requires drivers and interfaces to allow the control and monitoring of sensors and actuators. The thesis explains the process, as well as the hardware and software implemented.