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1
Hall, Jacob Griffin Hall. « Water in Knots ». Bowling Green State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1499102788266564.
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Simmers, Lauren Michelle. « Deeper than Water ». University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1555266957811109.
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Greenberg, Julie Anne. « Remembering Land Remembering Water ». The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1275406836.
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Newman, Kathleen A. (Kathleen Anne). « Cycling of fine particles between water and sediments ». Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/13629.
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Adams, Irena Zdena. « Exploration of water-based inks in fine art screenprinting ». Thesis, University of Ulster, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263243.
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Brook-Roberge, Daniel Grant. « Measurements of neutrino interactions on water using a fine-grained scintillator detector with water targets ». Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43215.
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Measurements of neutrino interaction cross-sections are important for the study of neutrino oscillations. For the T2K experiment, which has a near detector with a primarily carbon target and a far detector with
an oxygen target, the cross-section difference is important for correctly comparing the neutrino fluxes at the two detectors. This dissertation presents a first measurement of the ratio between oxygen and carbon of the muon neutrino charge-current inclusive cross-section using the T2K near detector, ND280. The design and construction methods of the water target system in the ND280 Fine-Grained Detector (FGD) will be discussed, as will a new algorithm for reconstructing particle tracks contained within the FGD. The data analysis leading to the cross-section ratio measurement will be described. It is based on a statistical subtraction method which extracts the contribution of the FGD water mass to the total interaction rate for the FGD with water targets. We find an oxygen/carbon ratio of 1.129 ± 0.114 (stat) ± 0.044 (syst) from the ND280 data, a 1.39σ difference from the Monte Carlo prediction of 0.954 ± 0.029.
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Evans, Douglas. « Soil water regime, root water extraction and the growth of fine roots of Sitka Spruce ». Thesis, University of Aberdeen, 1988. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU020973.
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The effect of removing soil water stress on fine root growth and the pattern of water use was studied by irrigating a small plot (20 m x 20 m) of 40 year old Sitka spruce. A control plot was established close by. Soil water content and soil matric potential were measured independently on both plots at several depths. Root growth was measured using monthly coring for the surface horizons (c. 10 cm depth) and ingrowth cores to study rooting at depth. In the absence of irrigation the 2 plots had similar water regimes. The irrigation kept matric potential > 20 kPa and water content > 20%. Areas between trees were wetter than areas close to stems and wetted up more during periods of rainfall. This is in contrast to young plantations where stemflow accounts for a much larger proportion of precipitation reaching the forest floor. At field capacity most of the water uptake was from near the surface but as the profile dries the proportion from depth increases, at the end of a dry period 50% of uptake was from the bottom half of the rooted zone. Water uptake from below the rooted zone was small. Irrigation had a significant effect on root tip density and on small root mass but not on fine and dead root masses. Root tip density stayed high through the summer with irrigation but fell on the control plot, the number of tips began to increase earlier on the control plot. This is interpreted as irrigation increasing the longevity of tips from 2-3 months (control) to 5 months. Rewetting of the soil in autumn appears to act as a cue for an increase in root growth. Irrigation had no effect on root growth at depth and there was no difference in growth at different depths on either plot.
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Rinne, John N. « Relationship of Fine Sediment and Two Native Southwestern Fish Species ». Arizona-Nevada Academy of Science, 2001. http://hdl.handle.net/10150/296569.
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Smith, Andrew. « Dynamical behaviour of water-immersed fine grains subjected to vertical vibration ». Thesis, University of Nottingham, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438426.
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Johnston, S. A. « Mitigation of gas and vapour cloud explosions using fine water sprays ». Thesis, University of Salford, 2015. http://usir.salford.ac.uk/34129/.
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For the past fifty years or so, there has been a great deal of interest in the use of water based explosion suppression systems, designed to mitigate or reduce the impact of thermal explosions and their consequential overpressures, which may be as high as 2MPa in outdoor environments. This level of interest has been heightened in more recent years due to a number of high loss explosion events including, Flixborough, UK (1974), Piper Alpha, North Sea (1998) and Buncefield, UK (2005). All of the previous research has focused on the suppression and mitigation proficiency of existing or new water deluge systems, which deploy sprays containing droplets 200≤D32≤1000μm. Where a high speed flame propagates through a region of spray containing such droplets, the flow ahead of the flame will hydrodynamically break up the droplets into fine mist, which in turn will act as a heat sink in the flame, with a resulting degree of suppression. These studies concluded that in most cases, existing deluge systems contributed to a global reduction in flame speed and thus caused a decrease in the resultant damaging overpressures. This present study however, is focused on the mitigation of slow moving deflagrations with resulting speeds of ≤30m/s. A flame travelling at such low relative speeds will not possess the inertia to inflict secondary atomisation by hydrodynamic break up. Consequently, the droplets within the spray must be small enough to extract heat in the short finite moments that the flame and droplets interact (approximately 0.03ms for a representative 1mm thick flame front). Previous theoretical studies have suggested that droplets, D32, in the order of 10μm - 20μm will be required to successfully mitigate combustion without relying on further droplet break up. To date, there have been no other published experimental studies in this area. An innovative high pressure atomiser known as a Spill Return Atomiser (SRA) was selected, which contained a unique swirl chamber and was originally developed for decontamination and disinfection. The efficient atomisation of the SRA produced fine sprays containing droplets, D32, 15μm - 20μm. A series of „cold trials‟ were conducted to further develop the single SRA, which manifested in the creation of several exclusive single and multiple spray options in counter, parallel and cross flow, with the direction of the propagating flame. These new configurations were supplied with deionised water at a liquid pressure of 13MPa and were qualitatively analysed using High Definition (HD) imagery and quantitatively characterised using non-intrusive laser techniques. During the development stages of this study the SRA spray cone angle was increased from 34.7˚ to 49.2˚and the exit orifice flow rate was raised from 0.295 L/min to 1.36 L/min. The increase in flow rate provided a number of spray options ranging from 17≤D32≤29μm, with liquid volume flux of 0.011 cm3/s/cm2 - 0.047cm3/s/cm2 and mean droplet velocity of 0m/s - 21.4m/s, with the resulting characteristics giving way to complete explosion mitigation qualities. The second phase of this study was to conceive, design and build a suitable apparatus capable of producing slow representative flame speeds within the range of 5 m/s - 30m/s. In excess of 250 mitigation „hot trials‟ were performed using the unique conformations produced during the „cold trials‟, whereby a configuration consisting of 4 x SRA‟s in cross flow (X/F) configuration, successfully and repeatedly, completely mitigated homogeneous methane-air mixtures throughout the whole flammable range E.R. 0.5≤(ϕ)1.0≤ 1.69 (5 - 15%), with flame speeds ranging from 5 - 30m/s. The combined spray configuration consisted of four SRA‟s which were 105mm apart and each opposed by 120˚, thus providing a total spray region of 315mm (spray centre to centre). As the sprays did not overlap or converge, the liquid volume flux remained as 0.047cm3/s/cm2. With droplets, D32, ≤30μm generally requiring impact velocities of approximately ≥142.83m/s to break up further, the flame speeds experienced in these trials of ≤30m/s would not have caused hydrodynamic break up of the droplets in the sprays. Therefore, due to the flame speeds and drop sizes utilised in this study, the droplets entering the flame front would have been in their original form. Although some comparisons were made using the experimental data with Computational Fluid Dynamics (CFD), it proved to be an extremely complicated phenomenon. This was due to the presence and interaction of the complexities of the combustion process and other variables such as water droplet dynamics and heat transfer modes. As such, a set of recommendations have therefore been proposed in pursuing this work in future projects.
11
Bartrand, Timothy A. Haas Charles N. Farouk Bakhtier. « High resolution experimental studies and numerical analysis of fine bubble ozone disinfection contactors / ». Philadelphia, Pa. : Drexel University, 2006. http://hdl.handle.net/1860/1214.
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Okunaka, Sayuri. « Water-based Synthesis of Oxide Semiconductor Fine Particles for Efficient Photocatalyst Systems ». 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215563.
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Dey, Fiona. « Study of the thickness of adsorbed water layers by atomic force microscopy ». Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/844499/.
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The effect of ambient humidity and adsorbed water can be of critical importance in the processing of fine powders in air. Adsorbed water layers can influence the adhesive properties of the powder and may lead to difficulties in processing and handling. It has been shown, in the current work, that in ambient conditions the interaction between two solid surfaces is dominated by the force arising from the presence of adsorbed water layers. In the current work an atomic force microscopy technique has been developed to determine the separation distance at which two solid surfaces, i.e. the AFM cantilever tip and the sample surface, 'jump' into contact. From the separation distance the thickness of the adsorbed water layers on the cantilever tip and sample surface can be determined based on an analytical method originally developed by Forcada (1993), which considers the interacting forces which cause the 'jump' to contact. The adsorbed layer thickness, as a function of relative humidity, has been determined for silicon wafer, using the AFM technique. This localized adsorption isotherm has been compared with those published by other investigators, who have used different measurement techniques on large sample areas. The adsorption isotherm determined using the AFM technique reports adsorbed layer thicknesses that are significantly larger than those measured by other investigators. Adsorption isotherms have been determined, using the AFM technique, for three forms of a-lactose monohydrate, which is widely used throughout the pharmaceutical industry. It was observed that each form of lactose gave a different level of water adsorption. Laboratory grown crystals exhibited the greatest levels of moisture adsorption, while commercially produced milled a-lactose displayed lower levels of water adsorption. Differences in surface roughness may possibly explain the variation. For rough samples the probe tip makes contact with surface asperities and therefore does not detect the presence of condensed water in the surface valleys. It is also possible that surface contamination and process history may have influenced the levels of water adsorption but these are complex effects to quantify. Water adsorption isotherms were measured on bulk samples of classified lactose, to attempt to validate the AFM technique, developed in the current study. It can be observed that the adsorbed layer thicknesses determined using AFM are significantly larger than those inferred from bulk measurements. The AEM method provides layer thickness values which are approximately four times larger than what are believed to be the true values. This is seen for tests on silicon, aluminium and lactose surfaces. This discrepancy is thought to arise from the presence of the probe tip on the surface causing a local spatial inhomogeneity. The associated increase in surface potential will promote nucleation of water molecules, leading ultimately to capillary condensation.
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Crayford, Andrew Philip. « Suppression of methane-air explosions with water in the form of 'fine' mists ». Thesis, Cardiff University, 2004. http://orca.cf.ac.uk/55919/.
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This thesis is concerned with the combustion hazard posed when there are accidental releases of methane from plant, particularly within the petrochemical 'exploration and production' industry. At the present time, such explosion hazards are controlled using explosion suppression systems based around Halon 1301 deployment. However, due to its environmental impact, such methods are being reviewed with the objective being their replacement with environmentally friendly alternatives. During the course of this study, the effect of water in the form of vapour and 'fine' mists has been investigated to determine its effectiveness in the containment and control of a potential methane explosion. Laminar flame/water interaction has been studied in considerable detail, and to a lesser extent the interaction with turbulent burning mechanisms has been studied through a demonstration study based on the conclusions of the laminar flame studies the efficiency of water in various concentrations and states (vapour or liquid-droplets) has been appraised. The research studies have also necessitated fundamental studies of droplet formation via supersaturated vapours, within small-scale laboratory test facilities, and methods suitable for generating large-scale sprays deemed suitable for the replacement of Halon systems were then appraised and characterised so as safety systems of the future may be optimised. The laminar test programme illustrated that water is a competitive explosion suppressant capable of extinguishing a fully propagating flame. It was found that water vapour and 'fine' water droplets are most effective in the mitigation of methane-air flames during early flame formation when curvature effects are a predominant factor, with 'fine' water droplets being more effective than vapour at this time. Turbulent experiments demonstrated that water in the form of 'fine' droplets can be used to fully arrest a propagating stoichiometric methane-air explosion, at concentrations probably less than the molar water concentration associated with inerting methane air explosions. A system based on the 'flashing' concept was fully characterised to illustrate that sprays similar to those utilised in the laboratory combustion work can be produced in a full- scale release, leading to the conclusions that Halon based systems may in the near future be replaced by environmentally sound explosion suppression systems that utilise water.
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Wiegand, Aaron Nathaniel. « Modelling photochemical production of fine particulates in a toluene/NOx/water vapour system ». Thesis, Queensland University of Technology, 1999. https://eprints.qut.edu.au/36975/1/36975_Digitised%20Thesis.pdf.
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This work investigates the computer modelling of the photochemical formation of smog products such as ozone and aerosol, in a system containing toluene, NOx and
water vapour. In particular, the problem of modelling this process in the Commonwealth Scientific and Industrial Research Organization (CSIRO) smog chambers, which utilize outdoor exposure, is addressed. The primary requirement for such modelling is a knowledge of the photolytic rate
coefficients. Photolytic rate coefficients of species other than N02 are often related to JNo2 (rate coefficient for the photolysis ofN02) by a simple factor, but for outdoor
chambers, this method is prone to error as the diurnal profiles may not be similar in shape. Three methods for the calculation of diurnal JNo2 are investigated. The most
suitable method for incorporation into a general model, is found to be one which determines the photolytic rate coefficients for N02, as well as several other species,
from actinic flux, absorption cross section and quantum yields. A computer model was developed, based on this method, to calculate in-chamber photolysis rate
coefficients for the CSIRO smog chambers, in which ex-chamber rate coefficients are adjusted by accounting for variation in light intensity by transmittance through
the Teflon walls, albedo from the chamber floor and radiation attenuation due to clouds. The photochemical formation of secondary aerosol is investigated in a series of toluene-NOx experiments, which were performed in the CSIRO smog chambers. Three stages of aerosol formation, in plots of total particulate volume versus time, are identified: a delay period in which no significant mass of aerosol is formed, a regime of rapid aerosol formation (regime 1) and a second regime of slowed aerosol formation (regime 2). Two models are presented which were developed from the experimental data. One model is empirically based on observations of discrete stages of aerosol formation and readily allows aerosol growth profiles to be calculated. The
second model is based on an adaptation of published toluene photooxidation mechanisms and provides some chemical information about the oxidation products.
Both models compare favorably against the experimental data.
The gross effects of precursor concentrations (toluene, NOx and H20) and ambient conditions (temperature, photolysis rate) on the formation of secondary aerosol are
also investigated, primarily using the mechanism model. An increase in [NOx]o results in increased delay time, rate of aerosol formation in regime 1 and volume of aerosol formed in regime 1. This is due to increased formation of dinitrocresol and furanone products. An increase in toluene results in a decrease in the delay time and
an increase in the rate of aerosol formation in regime 1, due to enhanced reactivity from the toluene products, such as the radicals from the photolysis of benzaldehyde.
Water vapor has very little effect on the formation of aerosol volume, except that rates are slightly increased due to more OH radicals from reaction with 0(1D) from
ozone photolysis. Increased temperature results in increased volume of aerosol formed in regime 1 (increased dinitrocresol formation), while increased photolysis
rate results in increased rate of aerosol formation in regime 1. Both the rate and volume of aerosol formed in regime 2 are increased by increased temperature or
photolysis rate.
Both models indicate that the yield of secondary particulates from hydrocarbons (mass concentration aerosol formed/mass concentration hydrocarbon precursor) is proportional to the ratio [NOx]0/[hydrocarbon]0
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Zhang, Qi. « Chemistry of organic nitrogen in atmospheric waters and fine particles / ». For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2002. http://uclibs.org/PID/11984.
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Valentine, Henry Richard. « A fine-scale volumetric census of the water masses of the Agulhas retroflection area ». Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/22162.
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Two studies of the quantification of water masses around southern Africa are described in this thesis. The first, a pilot study, is concerned with the volumetric analysis of historic hydrographic data from the region off the South African west coast. It uses data that have been collected with various instruments over a considerable period of time and with relatively poor vertical and horizontal resolution. Nevertheless meaningful and significant results have been obtained: (i) The T/S characteristics of the upwelling domain and the open-ocean are significantly different and show no overlap. Upwelled water is derived from different parts of the South Atlantic Central Water mass. (ii) Upwelled water, irrespective of its particular origin the Central Water mass, eventually is heated to a limit of 23°C. (iii) The volume of water in each bivariate T/S class of Central Water, which is available for upwelling, are constant. This implies that the intensity of upwelling may be estimated from the salinity of the upwelled water only. The second or main study is concerned with the Agulhas Retroflection area. This is located in the broader South-East Atlantic/South West Indian ocean region, which is identified as a serious gap in a previously published fine-scale volumetric census of the world ocean. Recently collected, high quality hydrographic data make it possible to rectify this. This is the principle objective of this thesis. Some results include: I. The subtle differences between the Central water of South Atlantic Ocean origin and that of the South Indian ocean were addressed. These differences are real and distinguishable as is shown using both historic data and high quality hydrographic data. 2. For the first time, reliable quantitative estimates for the warm and thermocline water masses are produced. The warm, saline surface water of the Agulhas Retroflection area contributes very little to the overall volume of the upper 1500 m of the water column. 3. The low salinity water from south of the Subtropical Convergence is spread widely (in T/S space) on the less saline side of the three-dimensional volumetric diagrams and has very little volume (less than 1% of the total volume). 4. The more saline, higher volume section of the Central Water in this region corresponds to South West Indian Central Water. 5. Twenty five percent of the total volume of water in this region is contained in only 21 fine-scale bivariate classes. 6. Fifty percent of the water (contained in 71 classes) has a temperature below 3°C. If the lower volume. non-ranked classes were added then almost seventy percent (67,26%) of all the water in the Retroflection area would be colder than 3°C. The results of this census are compared with those of the world ocean census. Although the volume per bivariate class interval is not of the same order of magnitude, the results are remarkably similar. The water masses of the Retroflection area are less diverse than those of the world ocean.
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Booth, Paula. « The effect of water consumption on schoolchildren's fine motor skills, cognitive function and mood ». Thesis, University of East London, 2015. http://roar.uel.ac.uk/5017/.
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Previous research has suggested that dehydration may have a negative effect on some aspects of mood, cognitive performance and motor skills (Benton, 2011). Furthermore, a large proportion of children arrive at school in a dehydrated state (Baron, Courbebaisse, Lepicard, & Friedlander, 2015). The present work investigated whether supplementing children with water may, as a consequence of reducing dehydration, improve their cognitive performance and motor skills. In studies 1, 2, 3 and 5, it was found that tasks that predominantly tested motor skills, were improved in children who had a drink, compared to those who did not. Furthermore, study 3 showed that this effect was moderated by hydration status. One theoretical explanation for the poorer performance of dehydrated children is that they may lack the neurological resources to sustain their effort and thus performance does not improve over time. In support of this, these studies showed that, when re-hydrated, performance on these tasks improves to the level of non-dehydrated children. Study 2 showed that the number of errors increased in a StopSignal task in children that had high self-rated levels of thirst, compared to low levels: and hydration status did not moderate this effect. A possible explanation for the increased number of errors in children with high self-rated thirst is that the thirst sensation diverts attention away from the task, causing task performance to deteriorate. In study 4, it was observed that there was a large variation in intra-individual and inter-individual hydration scores throughout the day, which was not related to volume drank or levels of thirst. Further studies should use imaging techniques to study brain activity during dehydration and rehydration, and during periods of high thirst, to help to further elucidate the mechanism underlying the negative effect of dehydration on motor performance, and the effect of self-rated thirst on attention.
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Arriaga, Odra O. « Nature, Essence and Spirit| An Artistic Process of Space, Lines and Color from the Level of Cells to the Large Oceanic Water World ». Thesis, The University of Texas Rio Grande Valley, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10263731.
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The methods, experimentations, philosophies and influential artists mentioned in this thesis all form part of my artistic exploration and art from the level of cells to the large oceanic water world. As an artist of Fine Arts at the University of Texas, Rio Grande Valley, my main emphasis is to associate these concepts with my personal experiences, cultural traditions and artistic perspectives with my likes for lines, colors and spaces in what I called, Nature, Essence and Spirit. Furthermore, my artistic approach was mostly influenced by the views of artists such as, Vasily Kandinsky, Frank Stella, Piet Mondrian, Paul Klee, Dale Chihuly and Tauba Auerbach.
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Salant, Nira Liat. « Some physical and biological factors influencing the fate of fine clastic particles in flowing water ». Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/9590.
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An experimental flume study was conducted to assess the influence of several physical and biological factors on the movement and deposition of fine particles (< 125 µm) in flowing water. Mechanisms of particle movement were elucidated from measurements of flow hydraulics, particle concentrations, surface deposition, and subsurface infiltration for varying flow rates, bed sand fractions, particle densities, initial concentrations, and periphyton structures. Results showed that low flows slowed total deposition, an unexpected result given the lower near-bed Reynolds stresses and velocities of this condition. Similarly, a bed with a high sand fraction also slowed total deposition despite having lower near-bed Reynolds stresses. A higher amount of surface deposition to the high sand bed was offset by limited subsurface deposition, likely due to the clogging of pore spaces by fine sand and reduced advective transport. Particle density also significantly altered deposition rate but had no effect on particle infiltration or flow hydraulics. Along a gradient of low to high initial concentrations, deposition rate and infiltration increased, due to greater particle availability and an increase in particle interactions. A comparison of theoretical and measured concentration profiles showed that for fine particles the Rouse equation, using a depth-integrated particle size, performed as well as or better than more complex models. All models under-predicted concentrations of low-density plastic particles, over-predicted at low concentrations, and performed better with a high sand bed.
Periphyton had a significant effect on hydraulics and deposition for a range of structures, densities and spatial scales. High density, closed periphyton patches compacted under high flows resulted in higher velocities and lower near-bed Reynolds stresses by constricting the flow depth and smoothing the bed surface. Lower density patches increased bed roughness, reducing near-bed velocities and transferring turbulent shear upward. Mucilaginous diatoms at low to moderate biomasses increased deposition rate and surface deposition by reducing near-bed Reynolds stress and enhancing particle adhesion. However, at high biomasses, diatom assemblages clogged interstitial spaces and reduced the amount of subsurface deposition thus slowing total deposition. In contrast, deposition occurred more slowly for most growth stages of filamentous algae, possibly due to partial clogging of the bed and a lack of surface adhesion. However, later algal growth stages increased Reynolds stress and advective transport, in turn increasing the amount of subsurface deposition and thus total deposition rate.
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Do, Tan Manh. « Excess pore water pressure generation in fine granular materials under cyclic loading -A laboratory study ». Licentiate thesis, Luleå tekniska universitet, Geoteknologi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-83517.
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Madsen, Matthew David. « Measurement of Fine Spatial Scale Ecohydrologic Gradients in a Pinyon-Juniper Ecosystem ». DigitalCommons@USU, 2008. https://digitalcommons.usu.edu/etd/24.
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With the dramatic expansion of pinyon-juniper woodlands over the last century, improved understanding of how these woodlands modify infiltration properties is needed, in order for land managers to make informed decisions on how to best manage their specific resources. However, current methods for measuring soil infiltration are often limited by low sample sizes and high experimental error, due to constraints associated with remote, non agricultural settings. This thesis first presents a scheme for automating and calibrating two commercially available infiltrometers, which allows collection of a large number of precise unsaturated infiltration measurements in a relatively short period of time. Secondly, a new method to precisely determine saturated hydraulic conductivity from small intact soil cores collected in the field is demonstrated. This method removes bias due to measurement error using a multiple head linear regression approach. Finally, hundreds of fine spatial scale measurements of soil sorptivity, unsaturated hydraulic conductivity, saturated hydraulic conductivity, soil water content, and other soil descriptive measurements along radial line transects extending out from the trunk of juniper (Juniperus osteosperma) and pinyon pine (Pinus edulis) trees. Within the subcanopy of these trees, interactions among litter material, root distributions, and hydrophobic soil significantly influence ecohydrologic properties by limiting and redirecting infiltration below the soil surface. Consequently, hydrophobicity appears to be a mechanism that promotes survival of woody vegetation in arid environments, through decreasing evaporation rates from the soil surface. We further demonstrate how differences in unsaturated infiltration and soil water content between the subcanopy and intercanopy zones are not discrete. Unsaturated infiltration was significantly lower within the subcanopy than in the intercanopy, and increased by eight-fold across a gradient extending outward from near the edge of the canopy to approximately two times the canopy radius. This gradient was not strongly related to soil moisture. In the intercanopy, increasing structural development of biological soil crust cover beyond this gradient was positivity correlated with infiltration capacity. Consequently, these results indicate that the spatial location of the trees should be considered in the assessment and modeling of woody plant and biological soil crust influence on infiltration capacity in a pinyon-juniper ecosystem.
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Regmi, Sanjeev. « EFFECT OF PLASTICITY AND INITIAL COMPACTION CONDITIONS ON SOIL WATER CHARACTERISTICS CURVE OF FINE-GRAINED SOILS ». OpenSIUC, 2019. https://opensiuc.lib.siu.edu/theses/2625.
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The soil water characteristics curve (SWCC) of a soil plays an important role in study of unsaturated soil mechanics. The behavior of unsaturated soil is a complex phenomenon to understand and the direct measurement of unsaturated soil properties in laboratory or in field is costly and time consuming. Knowing the SWCC of a soil is useful in estimating the unsaturated property of a soil, which is close to the natural soil conditions and can be used in effective design procedure. The present study deals with the effect of plasticity and initial compaction conditions of a soil in the SWCC by using SWC-150 (Fredlund SWCC device) and WP4C dewpoint potentiometer. The test data obtained from both the device were best fitted using Fredlund and Xing (1994) equation (FX), Van Genutchen (1980) equation (VG), Burdine (1958) equation, and Mualem (1976) equation.
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Karadogan, Erol. « Numerical Modeling Of Re-suspension And Transport Of Fine Sediments In Coastal Waters ». Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12605676/index.pdf.
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In this thesis, the theory of three dimensional numerical modeling of transport and re-suspension of fine sediments is studied and a computer program is develped for simulation of the three dimensional suspended sediment transport. The computer program solves the three dimensional advection-diffusion equation simultaneously with a computer program prepared earlier for the simulation of three dimensional current systems. This computer program computes the velocity vectors, eddy viscosities and water surface elavations which are used as inputs by the program of fine sediment transport. The model is applied to Bay of Izmir for different wind conditions.
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Jones, Simon Richard. « Investigation into the wafer-scale integration of fine-grain parallel processing computer systems ». Thesis, Brunel University, 1986. http://bura.brunel.ac.uk/handle/2438/11135.
Texte intégralRésumé :
This thesis investigates the potential of wafer-scale integration (WSI) for the implementation of low-cost fine-grain parallel processing computer systems. As WSI is a relatively new subject, there was little work on which to base investigations. Indeed, most WSI architectures existed only as untried and sometimes vague proposals. Accordingly, the research strategy approached this problem by identifying a representative WSI structure and architecture on which to base investigations. An analysis of architectural proposals identified associative memory to be general purpose parallel processing component used in a wide range of WSI architectures. Furthermore, this analysis provided a set of WSI-level design requirements to evaluate the sustainability of different architectures as research vehicles. The WSI-ASP (WASP) device, which has a large associative memory as its main component is shown to meet these requirements and hence was chosen as the research vehicle. Consequently, this thesis addresses WSI potential through an in-depth investigation into the feasibility of implementing a large associative memory for the WASP device that meets the demanding technological constraints of WSI. Overall, the thesis concludes that WSI offers significant potential for the implementation of low-cost fine-grain parallel processing computer systems. However, due to the dual constraints of thermal management and the area required for the power distribution network, power density is a major design constraint in WSI. Indeed, it is shown that WSI power densities need to be an order of magnitude lower than VLSI power densities. The thesis demonstrates that for associative memories at least, VLSI designs are unsuited to implementation in WSI. Rather, it is shown that WSI circuits must be closely matched to the operational environment to assure suitable power densities. These circuits are significantly larger than their VLSI equivalents. Nonetheless, the thesis demonstrates that by concentrating on the most power intensive circuits, it is possible to achieve acceptable power densities with only a modest increase in area overheads.
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Squires, Robert Berry. « A Longitudinal Comparison of Fine Scale Environmental Risk Factors and Waterborne Bacterial Presence in Haiti ». Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1529494397372641.
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Usman, Muhammad [Verfasser]. « New applications of fine-grained iron oxyhydroxides as cost-effective arsenic adsorbents in water treatment / Muhammad Usman ». Hamburg : Universitätsbibliothek der Technischen Universität Hamburg-Harburg, 2020. http://d-nb.info/1229989579/34.
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Morris, Joshua Powell. « Residual Diesel Range Organics and Selected Frothers in Process Waters from Fine Coal Flotation ». Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/23174.
Texte intégralRésumé :
The purpose of this thesis is to examine some of the potential fates of processing reagents in a coal preparation plant. The focus is specifically on petro-diesel (termed "diesel" in this paper), which is used as a collector in the flotation of fine coal. Diesel range organics (DRO) and polyaromatic hydrocarbons (PAHs) are measured in aqueous samples using gas chromatography equipped with either a flame ionization detector (GC-FID) or a mass spectrometer (GC-MS). Samples are subjected to a variety of test conditions in order to understand the behavior of diesel compounds in coal processing streams.Results show that frother and collector reagents are not likely to partition completely to a single fraction of the process slurry. Further test work has shown that sub-ppm levels of DRO dominated by the water soluble fraction of diesel are expected to be present in process waters; however, PAHs and insoluble DRO may be removed via volatilization and/or degradation. DRO and PAHs are also expected to be desorbed from coal particles when contacted with fresh water. Flotation tests have revealed that low levels of DRO are found in both the concentrate and tailings processing streams with slightly higher concentrations being found in the concentrate stream. From the tests performed in this thesis, it appears as though there is no apparent environmental concern when coal preparation plants are operating under normal conditions.
Master of Science
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Chang, Jingwei, et 常经纬. « Effect of pore water salt content on the coefficient of earth pressure at rest of fine-grained soils ». Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/202253.
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Edwards, Patrick Michael. « Macroinvertebrates and Excessive Fine Sediment Conditions in Oregon Coastal Streams ». Thesis, Portland State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3629266.
Texte intégralRésumé :
The Pacific Coastal ecoregion contains large tracts of economically important forestlands that also serve as critical stream habitat for endangered Salmonids. Excessive fine sediment deposition in streams of this region is a major environmental concern in the region but difficult to measure directly. The use of stream invertebrates to monitor fine sediment conditions in streams requires careful consideration of several important factors that complicate their use as bioindicators including high spatial and temporal variability and covariance with other environmental variables.
To evaluate the use of stream invertebrates as bioindicators of excessive fine sediment, three hypotheses were tested. The first hypothesis was that invertebrates would be related to broad-scale climate variables (Chapter 2). The second hypothesis was that functional aspects of the invertebrate community would serve as useful indicators of excessive fine sediment condition. (Chapter 3). The third hypothesis was that invertebrates in streams with naturally high levels of sediment would be tolerant to fine sediment (<2 mm, Chapter 4). Hypotheses were tested using a temporal data set at two streams in western Oregon, spatial data from 214 sites across the Oregon Coast Range, and in-situ experiment conducted in streams with erosive or resistant geologies.
In the temporal study, both invertebrate density and functional traits were positively related to El Niño strength (R2 range = 0.22–0.36, ρ range = 0.008–0.04) and air temperature (R 2 range = 0.32–0.49, ρ range = 0.002–0.01). The spatial study identified several environmental and hydrological factors that exhibited strong negative controls on both fine sediment (Mantel r range 0.14–0.25, ρ range = 0.001–0.01) and invertebrate Scrapers (R2 range = 0.11–0.14, ρ range = 0.001–0.04). The result of the experimental study provide evidence that invertebrates in streams with erosive geologies exhibit tolerance to sediment addition when compared to invertebrates in resistant geologies (mean loss=15%, ρ <0.01) and that invertebrate grazing traits were most strongly associated with fine sediment dosing frequency (ρ <0.05).
The findings of this research demonstrate the role of geology in shaping invertebrate communities and their functional response to fine sediment addition and identify functional indicators that may be useful in different geologic settings. For environmental managers in the Pacific Coastal ecoregion, these findings are of potential value in assisting with the identification of biologically-relevant changes in stream fine sediment conditions and support efforts to balance economic needs in the region while protecting critical Salmonid habitat.
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Garrett, Louise. « ... of delay, hesitation and detour : resisting the constitution of knowledge : Walter Benjamin, re-search and contemporary art ». Thesis, University of the Arts London, 2016. http://ualresearchonline.arts.ac.uk/13610/.
Texte intégralRésumé :
The point of departure of this dissertation is a few words extracted from “Agesilaus Santander,” an autobiographical fragment Walter Benjamin wrote in 1933 while in exile on Ibiza. The first version reads: “...I came into the world under the sign of Saturn, the star of hesitation and delay ...” He later revised the latter clause to: “the star of the slowest revolution, the planet of detours and delays...” Through processes of suspension, obstruction and potentiality implied by ‘delay,’ ‘hesitation,’ and ‘detour’ as ‘methods’ of thinking through art, this thesis revisits aspects of Benjamin’s understanding of time, history, origin and the artwork through conditional readings of selected contemporary artworks. Specifically, I am interested in understanding certain contemporary art and theoretical practices as modalities of resistance to modernist art historical and critical frameworks. In this tactical resistance, immanent in Benjamin’s reading of modernity, ‘delay,’ ‘hesitation’ and ‘detour’ are seen as characteristic of a form of critical thinking through and about art and history. ‘Hesitation,’ ‘delay’ and ‘detour’ are then understood as unconventional ‘methods’ that seek to break away from prescribed, or disciplinary, pathways of reading and interpreting works of art. In order to explore these general issues, I sketch out critical constellations for three artworks, each of which both engages and resists pedagogical structures and processes. This underlying pedagogical theme is signposted by the titles of the three chapters: I. “Lecture: ... of delay in Robert Morris’s 21.3, (1964/1994)”; II. “Study: ...of hesitation in Bethan Huws’s Origin and Source I-VI, (1997)”; and III. “Essay: ...of detour in The Otilith Group’s Otilith III, (2009).” I offer ‘slow,’ conditional readings of the particularities and relational contexts of these works, re-inscribing Benjamin’s creative approach to critical research work embedded in the processes of both making and writing through art. Since my approach is tempered by structures of incompletion and indeterminacy embodied by delay, hesitation and detour, I address questions concerning the borders of the process of ‘reading’ artworks and of categorizing both the ‘artwork’ and the ‘artist’ as bounded conceptual unities. My engagement with these questions signifies both a resistance to and an opening out of the limits of representation.
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Epling, Leslie Rose. « Costume Designing for Theatre of the Absurd - Come and Go, Footfalls, and The Dumb Waiter ». Digital Commons @ East Tennessee State University, 2010. https://dc.etsu.edu/honors/6.
Texte intégralRésumé :
In October of 2010, ETSU staged three one-act plays in the Theatre of the Absurd genre--Come and Go and Footfalls by Samuel Beckett and The Dumb Waiter by Harold Pinter. This thesis gives a brief overview of Theatre of the Absurd and how Beckett and Pinter helped to shape and define the genre. It also gives an analysis of these three plays from the perspective of the costume designer.
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Raevskaya, Alexandra, Vladimir Lesnyak, Danny Haubold, Volodymyr Dzhagan, Oleksandr Stroyuk, Nikolai Gaponik, Dietrich R. T. Zahn et Alexander Eychmüller. « A Fine Size Selection of Brightly Luminescent Water-Soluble Ag-In-S and Ag-In-S/ZnS Quantum Dots ». Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-226647.
Texte intégralRésumé :
A size-selected series of water-soluble luminescent Ag–In–S (AIS) and core/shell AIS/ZnS QDs were produced by a precipitation technique. Up to 10–11 fractions of size-selected AIS (AIS/ZnS) QDs emitting in a broad color range from deep-red to bluish-green were isolated with the photoluminescence (PL) quantum yield reaching 47% for intermediate fractions. The size of the isolated AIS (AIS/ZnS) QDs varied from ~2 nm to ~3.5 nm at a roughly constant chemical compo- sition of the particles throughout the fractions as shown by the X-ray photoelectron spectroscopy.
The decrease of the mean AIS QD size in consecutive fractions was accompanied by an increase of the structural QD imperfection/disorder as deduced from a notable Urbach absorption “tail” below the fundamental absorption edge. The Urbach increased from 90–100 meV for the largest QDs up to 350 meV for the smallest QDs, indicating a broadening of the distribution of sub-bandgap states. Both the Urbach energy and the PL bandwidth of the size-selected AIS QDs increased with QD size reduction from 3–4 nm to ~2 nm and a distinct correlation was observed between these parameters.
A study of size-selected AIS and AIS/ZnS QDs by UV photoelectron spectroscopy on Au and FTO substrates revealed their valence band level EVB at ~6.6 eV (on Au) and ~7 eV (on FTO) and pinned to the Fermi level of conductive substrates resulting in a masking of any possible size- dependence of the valence band edge position.
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Sugla, Sarika Devi. « In search of the spirit ». Thesis, The University of Iowa, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1560702.
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Hahn, Walter [Verfasser], et Boris V. [Akademischer Betreuer] Fine. « Stability of Quantum Statistical Ensembles with Respect to Local Measurements / Walter Hahn ; Betreuer : Boris V. Fine ». Heidelberg : Universitätsbibliothek Heidelberg, 2016. http://d-nb.info/1180617177/34.
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Kostetskaya, Anastasia G. « The Water of Life and the Life of Water : the Metaphor of World Liquescence in Russian Symbolist Poetry, Art and Film ». The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1367511847.
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Neubert, Susann [Verfasser], Radim [Akademischer Betreuer] Berànek et Roland A. [Akademischer Betreuer] Fischer. « Interface engineering of photocatalysts for water decontamination and artifical photosynthesis of fine chemicals / Susann Neubert. Gutachter : Radim Beránek ; Roland A. Fischer ». Bochum : Ruhr-Universität Bochum, 2016. http://d-nb.info/1099702968/34.
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Bleyleben, Nicole. « Beyond the fine print : water sector reform and private sector participation : case study based on La Paz/El Alto PPP concession ». Thesis, London School of Economics and Political Science (University of London), 2012. http://etheses.lse.ac.uk/513/.
Texte intégralRésumé :
This dissertation sheds new light upon the complex interplay of factors (social, political and economic) that constrain the enabling environment for water sector reform and private sector participation (PSP) by analysing of the process of policy reform and the nature of stakeholder engagement in the provision of water and sanitation. Findings are based on an in depth case study of the La Paz/El Alto concession arrangement from 1997–2005, when the contract was abruptly terminated. The analysis is encompassed within the New Institutional Economics conceptual framework as it provides a holistic application of economic analysis on the role of incentives, institutions and behaviour, providing a common link in understanding between traditional economists and other social scientists, allowing for greater reflection as to the ways socio-political, cultural and historical contexts determine the behaviour of those involved in the water reform process. The delicate nature of the water sector provides evidence of how under certain institutional constraints, and where optimum accumulation of information is virtually impossible, human behaviour can become motivated by a volatile set of preferences, making it particularly difficult for policy-makers to manage the reform process and accurately predict reform outcomes. Research findings conclude that the difficulties policy-makers faced in reforming the water sector and introducing PSP in the case of La Paz/El Alto, stemmed from three fundamental factors: (i) The reform process did not consider how race-based socio-political and economic hierarchies, endemic in Bolivian history and culture, would influence intended outcomes; (ii) stakeholders underestimated the transaction costs involved in the process of reform and PPP implementation due to information and bargaining asymmetries; (iii) systemic barriers, beyond the control of stakeholders involved, constrained the space for partnership innovation and flexibility in the provision of water and sanitation, debilitating the possibilities for future collaboration between civil society, government and the private sector.
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Pfeil, Nicklaus Charles. « Poor Traits : Pottery City ». Kent State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=kent1493148806091519.
Texte intégral
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Jiang, Shuang. « Bacterial leaching from dairy shed effluent applied to a fine sandy loam under flood and spray irrigations ». Lincoln University, 2008. http://hdl.handle.net/10182/668.
Texte intégralRésumé :
Land application of wastes has become increasingly popular, to promote nutrient recycling and environmental protection, with soil functioning as a partial barrier between wastes and groundwater. Dairy shed effluent (DSE), may contain a wide variety of pathogenic micro-organisms, including bacteria (e.g. Salmonella paratyphyi, Escherichia coli. and Campylobacter), protozoa and viruses. Groundwater pathogen contamination resulting from land-applied DSE is drawing more attention with the intensified development of the dairy farm industry in New Zealand. The purpose of this research was to investigate the fate and transport of bacterial indicator-faecal coliform (FC) from land-applied DSE under different irrigation practices via field lysimeter studies, using two water irrigation methods (flood and sprinkler) with contrasting application rates, through the 2005-2006 irrigation season. It was aimed at better understanding, quantifying and modelling of the processes that govern the removal of microbes in intact soil columns, bridging the gap between previous theoretical research and general farm practices, specifically for Templeton soil. This study involved different approaches (leaching experiments, infiltrometer measurements and a dye infiltration study) to understand the processes of transient water flow and bacterial transport; and to extrapolate the relationships between bacterial transport and soil properties (like soil structure, texture), and soil physical status (soil water potential ψ and volumetric water content θ). Factors controlling FC transport are discussed. A contaminant transport model, HYDRUS-1D, was applied to simulate microbial transport through soil on the basis of measured datasets. This study was carried out at Lincoln University’s Centre for Soil and Environmental Quality (CSEQ) lysimeter site. Six lysimeters were employed in two trials. Each trial involved application of DSE, followed by a water irrigation sequence applied in a flux-controlled method. The soil columns were taken from the site of the new Lincoln University Dairy Farm, Lincoln, Canterbury. The soil type is Templeton fine sandy loam (Udic-Ustochrept, coarse loamy, mixed, mesic). Vertical profiles (at four depths) of θ and ψ were measured during leaching experiments. The leaching experiments directly measured concentrations of chemical tracer (Br⁻ or Cl⁻) and FC in drainage. Results showed that bacteria could readily penetrate through 700 mm deep soil columns, when facilitated by water flow. In the first (summer) trial, FC in leachate as high as 1.4×10⁶ cfu 100 mL⁻¹ (similar to the DSE concentration), was detected in one lysimeter that had a higher clay content in the topsoil, immediately after DSE application, and before any water irrigation. This indicates that DSE flowed through preferential flow paths without significant treatment or reduction in concentrations. The highest post-irrigation concentration was 3.4×10³ cfu 100 mL⁻¹ under flood irrigation. Flood irrigation resulted in more bacteria and Br⁻ leaching than spray irrigation. In both trials (summer and autumn) results showed significant differences between irrigation treatments in lysimeters sharing similar drainage class (moderate or moderately rapid). Leaching bacterial concentration was positively correlated with both θ and ψ, and sometimes drainage rate. Greater bacterial leaching was found in the one lysimeter with rapid whole-column effective hydraulic conductivity, Keff, for both flood and spray treatments. Occasionally, the effect of Keff on water movement and bacterial transport overrode the effect of irrigation. The ‘seasonal condition’ of the soil (including variation in initial water content) also influenced bacterial leaching, with less risk of leaching in autumn than in summer. A tension infiltrometer experiment measured hydraulic conductivity of the lysimeters at zero and 40 mm suction. The results showed in most cases a significant correlation between the proportion of bacteria leached and the flow contribution of the macropores. The higher the Ksat, the greater the amount of drainage and bacterial leaching obtained. This research also found that this technique may exclude the activity of some continuous macropores (e.g., cracks) due to the difference of initial wetness which could substantially change the conductivity and result in more serious bacterial leaching in this Templeton soil. A dye infiltration study showed there was great variability in water flow patterns, and most of the flow reaching deeper than 50 cm resulted from macropores, mainly visible cracks. The transient water flow and transport of tracer (Br⁻) and FC were modelled using the HYDRUS-1D software package. The uniform flow van Genuchten model, and the dual-porosity model were used for water flow and the mobile-immobile (MIM) model was used for tracer and FC transport. The hydraulic and solute parameters were optimized during simulation, on the basis of measured datasets from the leaching experiments. There was evidence supporting the presence of macropores, based on the water flow in the post-DSE application stage. The optimised saturated water content (θs) decreased during the post-application process, which could be explained in terms of macropore flow enhanced by irrigation. Moreover, bacterial simulation showed discrepancies in all cases of uniform flow simulations at the very initial stage, indicating that non-equilibrium processes were dominant during those short periods, and suggesting that there were strong dynamic processes involving structure change and subsequently flow paths. It is recommended that management strategies to reduce FC contamination following application of DSE in these soils must aim to decrease preferential flow by adjusting irrigation schemes. Attention needs to be given to a) decreasing irrigation rates at the beginning of each irrigation; b) increasing the number of irrigations, by reducing at the same time the amount of water applied and the irrigation rate at each irrigation; c) applying spray irrigation rather than flood irrigation.
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Jacoby, Jill Beth. « Art, Water, and Circles : In What Ways Do Study Circles Empower Artists to Become Community Leaders around Water Issues ». [Yellow Springs, Ohio] : Antioch University, 2009. http://etd.ohiolink.edu/view.cgi?acc_num=antioch1260285346.
Texte intégralRésumé :
Thesis (Ph.D.)--Antioch University, 2009.Title from PDF t.p. (viewed March 25, 2010). Advisor: Jon Wergin, Ph.D. "A dissertation submitted to the Ph.D. in Leadership and Change program of Antioch University in partial fulfillment of the requirements for the degree of Doctor of Philosophy 2009."--from the title page. Includes bibliographical references (p. 238-245).
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Hoy, Raymond S. « The Impact of Fine Sediment on Stream Macroinvertebrates in Urban and Rural Oregon Streams ». PDXScholar, 2001. https://pdxscholar.library.pdx.edu/open_access_etds/1678.
Texte intégralRésumé :
Urbanization, often characterized by high impervious surface area, can result in excessive inputs of fine sediments into urban streams. Excessive fine sediments can blanket the stream bed filling the interstitial space in the substratum, which may have adverse effects on stream biota. A field survey was conducted in Oregon urban and non-urban basins to investigate the relationship between fine sediments and stream macroinvertebrates. Physical, chemical, and biological data were collected from 59 stream sites in two urban and two rural streams. The stream sites fulfilled a continuous sediment gradient, which ranged from a low of 2% of fine sediment in the substrate to a high of 64% with an average of 22%. The % fines, in Clear Creek (rural basin) was significantly lower than in the urban basins (Johnson Creek and Tryon Creek) (p=0.005). Johnson Creek (mean=23%) had approximately three times more fine sediment than Clear Creek (mean=7%), while Tryon Creek (mean=32%) had nearly five times as much fine sediment as Clear Creek. EPT taxa richness was significantly higher in both rural streams than in both urban streams (p0.05). For example, regression analysis of EPT taxa richness vs. % fine sediments displayed a coefficient of determination (r2) value of 0.2. Other macro invertebrates metrics displayed similar patterns. The lack of significant correlations may be due to the cumulative effect of basin-wide "historical land use past". Past land use activity may have resulted in long-term reductions of sensitive taxa in the basin taxa pool and efforts to improve local habitats may not be quickly colonized by pollution sensitive taxa. Long-term degradation to the urban streams resulted in a relatively homogenous assemblage of macro invertebrates, which may have confounded the quantitative relationship between sediments and macroinvertebrates. This study suggests there is a clear difference between urban and non-urban streams in terms of macro invertebrates, which may be likely due to sediments, but the quantitative relationship between fine sediments and macro invertebrates is weak.
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Alshawmar, Fahad Abdulaziz. « Shaking Table Testing of Geotechnical Response of Densified Fine-Grained Soils to Cyclic Loadings : Application to Highly Densified Tailings ». Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/41892.
Texte intégralRésumé :
Liquefaction is a major challenge in geotechnical engineering in which soil strength and stiffness are compromised due to earthquake activity. Understanding and predicting the behaviour and liquefaction susceptibility of soils under cyclic loading is a critical issue in civil engineering, mining and protective engineering. Numerous earthquake-induced ground failure events (e.g., substantial ground deformation, reduced bearing capacity) or liquefaction in natural fine-grained soils or manmade fine-grained soils (i.e., fine tailings) produced by mining activities have been observed and reported in the literature. Tailings are manmade soils that remain following the extraction of metals and minerals from mined ore in a mine processing plant. Traditionally, such tailings are stored in surface tailings impoundments at the mine’s surface. However, geotechnical and environmental risks and consequences related to conventional tailings impoundments have attracted the attention of the engineering community to develop novel methods of tailings disposal and management to minimize geotechnical and environmental risks. Thus, engineers have introduced and implemented innovative tailings technologies—thickened tailings and paste tailings—as cost-effective means for tailings management in mining operations. As both thickened tailings and paste tailings have lower water content and higher solid content than tailings in conventional impoundments, these tailings may be more resistant to liquefaction. However, it should be noted that the seismic or cyclic behaviour of these thickened and paste tailings, with and without heavy rainfall effects, are not fully understood. There is little technical information or data about the behaviour and liquefaction of thickened and paste tailings under seismic or cyclic loading conditions.
The objective of the present PhD research is to investigate the response of layered thickened and paste tailings deposits, with and without heavy rainfall effects, to cyclic loads by conducting shaking table tests. To simulate the field deposition of thickened and paste tailings, tailings were deposited in three thin layers in a flexible laminar shear box (FLSB) attached to the shaking table equipment. A sinusoidal seismic loading at a frequency of 1 Hz and peak horizontal acceleration of 0.13g was applied at the bottom of the layered tailings deposits. Acceleration, displacement and pore water pressure responses to the cyclic loading were monitored at the middle depth of each layer of the tailings deposits. Regarding the acceleration response of these thickened and paste tailings deposits (without the effect of heavy rainfall), there was no difference between the middle of the bottom and middle layers or at the base of the shaking table. However, the acceleration at the middle of the top layer differed from the acceleration at the base of the shaking table. Throughout shaking, the layered tailings deposits (with and without the effect of heavy rainfall) exhibited contraction and dilation responses. The excess pore water pressure ratios of the layered thickened tailings deposit that was not exposed to heavy rainfall prior to shaking were found to exceed 1.0 during shaking. However, for the layered paste tailings deposit that was not exposed to the effect of heavy rainfall prior to shaking, the excess pore water pressure ratios were found to be lower than 0.85 during shaking. This reveals that without the effect of heavy rainfall, the layered thickened tailings deposit was susceptible to liquefaction, whereas the layered paste tailings deposit was resistant to liquefaction during shaking. The excess pore water ratios of the layered thickened and the paste tailings deposits that were exposed to heavy rainfall prior to shaking were found to be lower than 0.8 during shaking. This reveals that with the effect of heavy rainfall, the layered thickened and paste tailings deposits were resistant to liquefaction during shaking. The results and findings of this PhD research thus provide valuable information for the implementation of tailings in earthquake-prone areas.
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Ranc, Isabelle. « Modélisation de la fragmentation fine lors de la phase de déclenchement d'une explosion de vapeur ». Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10106.
Texte intégralRésumé :
Ce travail est motive par les etudes de surete relatives aux accidents graves des reacteurs a eau pressurisee, qui envisagent la fusion du coeur. Dans ce cadre, on etudie une des phases de l'explosion de vapeur ou interaction corium-eau, c'est-a-dire la vaporisation violente du refrigerant lors d'un choc thermique entre un liquide tres chaud et un liquide froid. L'objet de l'etude est la phase de declenchement de l'interaction, pendant laquelle une goutte de combustible, de l'ordre du centimetre, initialement entouree d'un film de vapeur, se fragmente en debris de l'ordre de la centaine de micrometres. Le modele decrit le cycle de croissance et de collapse d'une bulle de vapeur autour de la goutte et sa fragmentation. Les differentes etapes du scenario ont ete modelisees. Les points principaux sont : -la destabilisation du film ou de la bulle par des instabilites de rayleigh-taylor conduisant des contacts directs entre le corps chaud et le refrigerant, -les mecanismes de fragmentation obtenus a la suite de ces contacts. En particulier, pour le mecanisme d'emprisonnement de refrigerant a l'interieur de la goutte, le comportement thermique du refrigerant a ete decrit par une evaporation brutale lorsque la limite de surchauffe est atteinte, -le transfert de chaleur transitoire entre les fragments et le refrigerant et la production de vapeur importante. Sur ce dernier point, a l'issue d'une analyse bibliographique, le refroidissement des fragments a ete decrit par un transfert de chaleur transitoire, mettant en jeu la physique de l'ebullition par nucleation spontanee. Les resultats du modele sont compares de facon satisfaisante aux resultats experimentaux.
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Pinheiro, Rafael Costa. « Avaliação da distância máxima de absorção de nutrientes em formações florestais tropicais usando 15N como marcador / ». Botucatu, 2019. http://hdl.handle.net/11449/192690.
Texte intégralRésumé :
Orientador: Jean-Paul LaclauResumo: As mudanças climáticas têm causado alterações na temperatura e também nos regimes de precipitação do planeta, aumentando a probabilidade de ocorrência de secas mais severas, o que, no cenário florestal, pode resultar na mortalidade de florestas ao redor do mundo. Assim, é necessário um conhecimento mais detalhado sobre a dinâmica de absorção de água e nitratos pelas raízes das árvores, que explique o comportamento das árvores sob extrema seca. O objetivo do estudo foi avaliar a distância máxima do tronco e a profundidade máxima de absorção de nutrientes e água pelas raízes das árvores em florestas crescendo sobre Neossolos Quartzarênicos muito profundos, utilizando o 15N como marcador. As consequências do status social das árvores, comparando árvores dominantes e dominadas do mesmo genótipo numa floresta monoclonal foram estudadas em plantios de um clone híbrido de Eucalyptus urophylla x Eucalyptus grandis durante a estação seca. Os efeitos da sazonalidade (comparando as estações seca e chuvosa) foram estudados em três espécies do Cerrado: i) Xylopia aromatica (Lam.) Mart.; ii) Coussarea hydrangeifolia (Benth.) Müll.Arg.; and iii) Miconia albicans (Sw.) Steud. Além disso, foi avaliada a existência de uma complementaridade de nicho no solo entre essas espécies do Cerrado, com uma absorção do marcador em camadas diferentes. O marcador NO3--15N foi aplicado em talhões de eucalipto com 7 meses, 1,2 anos, 2,2 anos e 6,4 anos de idade, a várias profundidades do solo em 60 pontos, s... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor
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Ebanks, Davin K. « Blue Meridian : The Portraiture of Landscape ». Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1272900119.
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Biddulph, Matilda. « Testing the efficacy of mitigation measures for reducing fine sediment and associated pollutant delivery to and through rivers in agricultural catchments of England ». Thesis, University of Northampton, 2016. http://nectar.northampton.ac.uk/9543/.
Texte intégralRésumé :
Agricultural intensification has contributed to the degradation of freshwaters in the UK, through enhanced delivery of fine sediment and associated contaminants, leading to sedimentation and eutrophication. European legislation (Water Framework Directive 2000/60/EC) and subsequent UK government initiatives such as Catchment Sensitive Farming (CSF) and Demonstration Test Catchments (DTC), aim to improve the quality of freshwaters. The DTC programme aims to find cost-effective ways to reduce agricultural diffuse water pollution. This study aimed to monitor rivers in the Hampshire Avon DTC with existing and planned mitigation measures, to measure the effectiveness of the mitigation measures, and to develop an experimental design for wider application for pollution mitigation. The methods used and tested in this study were a combination of affordable, replicable and sustainable methods (in-stream sediment collection and water quality monitoring), more complicated, expensive, analytical laboratory methods (particle size, loss-on-ignition, geochemistry, mineral magnetism, environmental radionuclides), and sediment source fingerprinting. The mitigation measures were: improvement to farm infrastructure, a wooded and a grassed riparian buffer, and a constructed wetland and in-stream pond treatment train. The improved farm infrastructure (resurfacing of a farm track, installation of a retention pond, improvements to a drainage ditch) effectively reduced inputs of sediment and associated contaminants to the river, however, this had little positive impact on the river due to greater importance of inputs from other sources. The riparian buffers were reducing fine sediment and associated contaminant inputs laterally and from upstream, however, the effectiveness of the riparian buffers was undermined by a lack of riparian buffers upstream and by sub-surface field drains. Combined analysis of the river from the farm infrastructure in the headwaters (farm scale) to the wooded riparian buffer downstream (sub-catchment scale) showed a change in the dominant source of sediment. This highlighted that an experimental design would require monitoring at varying spatial scales, as individual farm scale mitigation measures may have little impact on an entire sub-catchment due to the importance of other sources from a larger drainage area. The constructed wetland and instream pond were not effective at reducing longitudinal delivery of fine sediment and associated contaminants due to issues related to maintenance and design, emphasising the importance of appropriate targeting, design, and maintenance of mitigation measures. The results from this study showed that the methods used would be suitable as part of an experimental design for wider application. Although complex and expensive, sediment source fingerprinting is essential for determining appropriate and cost-effective mitigation at farm and sub-catchment scales. Monitoring of the sediment and water quality using the affordable, replicable and sustainable methods could be managed by farmers and landowners across a dense spatial area, at a high temporal frequency, to ensure sustainable effectiveness of mitigation. There is a need for more co-working between policy makers and scientists to ensure appropriate funding and timescales for research are provided, and with farmers and landowners to improve understanding and vested interest in the contribution of agriculture to the degradation of water quality.
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Mikalovicz, Heloisa. « Solo e condições meteorológicas na composição da uva Cabernet Sauvignon ». Universidade do Estado de Santa Catarina, 2014. http://tede.udesc.br/handle/handle/2468.
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Capes
To evaluate the effects of soil and weather conditions in the grape, the objective this study was evaluate the influence of three soil classes (Pachic Humudeps, Typic Dystrudepts and Nitosol) and climatic factors (precipitation, maximum and minimum temperatures) on the quantitative and qualitative characteristics of Cabernet Sauvignon whegrapes (Vitis vinifera L). The experiment was conducted in São Joaquim, Santa Catarina in 2011/12 and 2012/13 season. In each soil 20 points were marked, where soil samples were collected for physical and chemical analysis. At each point we collected bunches for physical and chemical analysis and physical phenolic components of the grape. Data were submitted to analysis of variance (ANOVA) and the means were compared using the "t" test. The Nitosol and the Typic Dystrudepts, due to the position in the landscape and better drainage produce grapes with the most suitable composition for the preparation of wines, while the Pahic Humudeps due to higher water availability in years with higher rainfall has the composition of the grape negatively affected. Weather the 2012/13 crop, resulted in better physical characteristics of the grape and higher productivity compared to 2011/12
Para avaliar os efeitos do solo e das condições meteorológicas na uva, este trabalho teve como objetivo determinar a influência de três classes de solos (Cambissolo Húmico, Cambissolo Háplico e Nitossolo Bruno) e os fatores climáticos (precipitação-pluviométrica, temperaturas máximas e mínimas) sobre as características quantitativas e qualitativas da uva da variedade Cabernet Sauvignon (Vitis vinifera L). O experimento foi realizado no município de São Joaquim, Santa Catarina nas safras 2011/12 e 2012/13. Em cada classe de solo, foram demarcados 20 pontos, onde foram coletadas as amostras para as análises físicas e químicas. Em cada ponto foram coletados os cachos para determinações físicas e físico-químicas da uva. Os dados foram submetidos análise de variância (ANOVA) e as médias foram comparadas pelo teste “t”. O Nitossolo Bruno e o Cambissolo Háplico, devido à posição na paisagem e melhor drenagem produzem uvas com composição mais adequada à elaboração de vinhos, enquanto que o Cambissolo Húmico, devido ao maior armazenamento e disponibilidade de água em anos com maior volume pluviométrico tem a composição da uva afetada negativamente. As condições meteorológicas da safra 2012/13 resultaram em melhores características físicas da uva e maior produtividade em relação à safra 2011/12
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Frankel, Leah H. « The Gravity of the Ordinary ». The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406121839.
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Beserra, Carlos Felipe Saraiva. « Aspiratory PunÃÃo for fine needle in injury to nodular of the tireÃide : study of the precision of the ctopatolÃgica analysis in the University Hospital Walter CantÃdio ». Universidade Federal do CearÃ, 1998. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1232.
Texte intégralRésumé :
CoordenaÃÃo de AperfeiÃoamento de NÃvel SuperiorFine needle aspiration in thyroid disease: study on the accuracy of cytology at Hospital UniversitÃrio Walter CantÃdio (HUWC-UFC). This study analised the accuracy of fine-needle aspiration technique (FNA) in patients referred to the Departamento de Cirurgia of the Universidade Federal do Cearà (UFC). These patients presented of thyroid nodular disease. The intention of the study was also to establish the routine use of the FNA in these patients. It was also part of the study to analyse risk factors to malignant thyroid disease and the importance of complementary exam in the patients studied. All patients had their clinical history taken and underwent physical examination, prà operative de routine exam and measurement of thyroid hormones. The aspirative form FNA was subjected to cytologic and histologic studies. Thyroid scan, ultrasonography and serological test to detect antithyroid antibodies were not performed in all patients. Endemiological risk factors such as age and sex were analised regarding their association with malignant thyroid disease. Sixty-six (66) patients were studied. They presented with clinically palpable thyroid lumps and were subjected to surgical treatment, which indications obeyed clinical and cytologic criteria. 63 patients were female and 3 male. Age average was 41,5 years, varying from 12 to 72 years. Risk factors were identified as patients with: 08 lumps with fast growth (12,1%), 9 lumps with hard texture at physical examination (13,6%). (08) Eight patients presented at physical examination palpable lymphnods (12,1%) and one (1) patient had hoarseness (1,5%). Results from cytologic were grouped as: benign â 30 (45,5), follicular neoplÃsica â 16 (24,2%), suspicious of being malignant â 5 (7,6%), malignant â 12 (18,2%), and inadequate â 3 (4,5%). Histology showed 22 malignant neoplasias and 44 benign nodules. Statistical analysis regarding sex, age, presence of hard lumps and palpable neck lymphnods homolateral to the lump showed an increased association with malignant disease (Fisher; p<0,05). However, there was no increase association with malignant age, patients who presented hoarseness, with lumps, with fast growth, and varied number to lumps and with different sizes. Combining cytology and histology enable to obtain the following indicators: sensitivity â 78,6% specificity â 94,5%, value of prediction â 90,5%, predictive positive value â 91,6%, false-positive â 8,4%, predictive negative value â 90,0%, and falsenegative â 10,0%. When included cytological results classified as indetermined (suspicious of malignancy and follicular neoplÃsica) as positive for malignant disease the indicators in the same sequence above were: 85%, 62,8%, 69,0%, 53,3%, 46,7%, 89,3% and 10,0%. Thyroid scan was performed in 23 patients and revealed 20 hypocaptent lumps (87%) â 6 of which were malignant (33,0%). No malignancy was found in two (2) normocaptent lumps and one (1) following results: 36 patients presented single lumps, 14 patients â multiple lumps and 2 patients had normal ultrasonography exam. There was a higher of malignancy in patients with single lumps turned to be malignant. When evaluating hormonal function there was a higher percentage of malignancy inpatients with normal hormonal disease (37,9%) â 22 out of 58 patients. When hypothyroidism was fund 25% this patients (1 out of 4) presented malignancy of nodular thyroid diseases and creditate the method as safe at the HUWC/UFC.
PunÃÃo Aspirativa por Agulha em lesÃo Nodular da TireÃide: Estudo da PrecisÃo da AnÃlise CitopatolÃgica no Hospital UniversitÃrio Walter CantÃdio. Curso de PÃs-GraduaÃÃo (Mestrado) em Base da TÃcnica CirÃrgica e Cirurgia Experimental, do Departamento de Cirurgia do Centro de CiÃncias da SaÃde da UFC. Autor: Carlos Felipe Saraiva Beserra. No presente trabalho, objetivou-se analisar a precisÃo da punÃÃo aspirativa por agulha fina (PAAF), nos pacientes avaliados no Departamento de Cirurgia do Centro de CiÃncias da SaÃde do HUWC-UFC, portadores de lesÃes nodulares de tireÃide, bem como instituir como prÃtica rotineira o uso da punÃÃo na avaliaÃÃo destes pacientes. De forma secundÃria foram avaliados os fatores de risco para presenÃa de neoplasia maligna nas lesÃes nodulares de tireÃide e a importÃncia dos exames complementares, nestes casos. Todos os pacientes foram avaliados com histÃria clÃnica, exame fÃsico, exames prÃ-operatÃrios de rotina, dosagem dos hormÃnios triodotironina, e tireotropina, estudo citolÃgico e histolÃgico. A cintilografia, ultrassom e a sorologia para anticorpos antitireoideanos nÃo foram realizados em todos os pacientes. Os fatores de risco presentes, assim como a idade e o sexo, foram analisados em relaÃÃo à sua associaÃÃo com a presenÃa de neoplasias malignas. Foram avaliados 66 pacientes portadores de nÃdulos de tireÃide clinicamente palpÃveis, submetidos a tratamento cirÃrgico, cuja indicaÃÃo obedeceu a critÃrios clÃnicos e citolÃgicos. Desse total, 63 pacientes eram do sexo feminino. A mÃdia de idade foi de 41, anos, variando de 12 a 72 anos. Os fatores de risco, 09 com consistÃncia dura no exame fÃsico (13,6%), 09 pacientes apresentaram linfonodos clinicamente suspeitos (13,6%), e 01 apresentou rouquidÃo (1,5%). Os resultados da anÃlise citolÃgica foram agrupados como: benigno â 30 (45,5%), neoplasia folicular â 16 (24,2%), suspeito â 5 (7,6%), maligno â 12 (18,2%) e insatisfatÃrio â 3 (4,5%). No estudo histolÃgico, foi verificada a presenÃa de 22 neoplasias malignas e 44 lesÃes benignas. A avaliaÃÃo estatÃstica em relaÃÃo ao sexo masculino, presenÃa de nÃdulos duros e de linfonodos cervicais palpÃveis homolaterais ao nÃdulo mostrou maior associaÃÃo com presenÃa de cÃncer, estatisticamente significativa (Teste exato de Fisher; p<0,05). A anÃlise quanto à idade, à presenÃa de crescimento rÃpido, ao nÃmero ou o tamanho dos nÃdulos e à presenÃa de rouquidÃo nÃo apresentou associaÃÃo com presenÃa de neoplasia maligna, estatisticamente significante. No estudo da associaÃÃo entre citologia e histologia foram observados os seguintes Ãndices: sensibilidade de 78,6%, especificidade de 96,4%, valor de prediÃÃo de 90,5%, valor preditivo positivo de 91,6%, falso-positivo de 8,4%, valor preditivo negativo de 90,0% e falso-negativo de 10,0%. Quando foram incluÃdos os resultados indeterminados (suspeito e neoplasia folicular) como positivo para presenÃa de neoplasia maligna, na mesma seqÃÃncia anterior, os resultados foram: 85,0%, 62,8%, 69,0%, 53,3%, 46,7%, 89,3% e 10,6%. A cintilografia foi realizada em 23 pacientes e revelou 20 nÃdulos hipocaptantes (87%), dos quais 6 eram malignos (33%); nÃo foram registrados cÃnceres nos 2 nÃdulos normocaptantes e em nÃdulo hipercaptante. O ultrassom foi realizado em 52 pacientes, dos quais, 36 apresentavam nÃdulos Ãnicos, 14 nÃdulos mÃltiplos e em 2 casos a tireÃide, segundo o laudo do ultrassonografista, era normal. Verificou-se um maior percentual de cÃncer nos pacientes com nÃdulo Ãnico, 36,1% versus 21,4%, contudo, a anÃlise estatÃstica nÃo mostrou significÃncia. Na presenÃa de hipoecogenicidade do nÃdulo, 71% eram neoplasias malignas. A avaliaÃÃo da funÃÃo hormonal mostrou um maior percentual de cÃncer em pacientes com dosagens normais, 22 em 58 (37,9%), enquanto nos hipotireoideanos foi de 1 em 4 (25%), e nenhum nos 4 pacientes com hipertireoidismo. Os resultados aqui apresentados, portanto, confirmam a precisÃo da PAAF na abordagem da patologia nodular tireÃideana e credenciam o mÃtodo como seguro, no HUW-UFC.