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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Experimental Investigation and Statistical Analysis of Entrainment Rates of Particles in Suspended Load / 浮流粒子の連行率の実験的研究および統計的分析

Yao, Qifeng 24 September 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22032号 / 理博第4536号 / 新制||理||1651(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)准教授 成瀬 元, 教授 生形 貴男, 准教授 堤 昭人 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
142

Formation conditions of bedforms under sediment-laden gravity currents / 堆積物重力流ベッドフォームの形成条件

Ohata, Koji 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23017号 / 理博第4694号 / 新制||理||1673(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)准教授 成瀬 元, 准教授 堤 昭人, 教授 生形 貴男 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM
143

Assessment of coastal erosion to create a seagrass vulnerability index in northwestern Madagascar using automated quantification analysis

Arslan, Nat January 2020 (has links)
The seagrass extent has been declining globally. The human activities that are most likely to cause seagrass loss are those which affect the water quality and clarity. However, turbidity following coastal erosion is often left out from marine ecosystem vulnerability indices. This study quantified the coastal erosion for Tsimipaika Bay in northwestern Madagascar by using change detection analysis of satellite imageries. The annual coastal erosion data was then used to create an index for seagrass vulnerability to turbidity following coastal erosion. Considering that the height of seagrass species plays an important role in their survival following turbidity, the seagrass vulnerability index (SVI) was based on two factors; seagrass species height and their distance to the nearest possible erosion place. The results for the coastal erosion showed that the amount of erosion was particularly high in 1996, 2001 and 2009 for Tsimipaika Bay. The highest erosion occurred in 2001 with a land loss area of about 6.2 km2 . The SVI maps revealed that 40% of the seagrass communities had minimum mean SVI values in 2001 and 50% had the maximum mean SVI during the year 2009. This study showed that it is possible to use coastal erosion to measure seagrass vulnerability; however, the index requires configuration such as including the total amount of annual coastal erosion and incorporating bathymetric data. The entire project was built and automated in Jupyter Notebook using Python programming language, which creates a ground for future studies to develop and modify the project.
144

Ionokomplexy hyaluronanu / Hyaluronan ion complexes

Cimalová, Jana January 2013 (has links)
This diploma thesis is focused on the study of physical and chemical properties of hyaluronan and cationic surfactant. As the cationic surfactant Septonex was used. The influence of the environment on the system, the effect of molecular weight of hyaluronan, and its concentration was studied. Then, the study of the influence and the effects of concentration of Septonex on the interaction of hyaluronan-surfactant followed. Different methods of measurement were chosen to characterize these ionokomplexes. The critical micelle concentration of the surfactant itself was measured, and then also with the addition of hyaluronan by spectrofluorimetry with fluorescent probe pyren. It was found, that hyaluronan forms gel with Septonex. On this basis, gels were prepared for three different molecular weights of hyaluronan – 300 kDa, 806 kDa and 1697 kDa. Gels were prepared in a ratio of hyaluronan – surfactant 1:1. In gels prepared in this way, the influence of environmental water and 0.15 M NaCl was studied and it was found that at 0.15 M NaCl clear gels are formed. Selected samples of the gels were then measured with oscillatory testing and the rheological behavior of gels of Septonex was studied. As the last method the turbidimetric measurement was chosen, which characterized the turbidity point in the gradual addition of Septonex to sodium hyaluronate solution. Again, the effect of the molecular weight of hyaluronan and its concentration in two environments - water and 0.15 M NaCl was evaluated. It was found that 0,15 M NaCl suppresses formation of turbidity and formation of precipitates.
145

Technico-economic evaluation of used rolling oil treatment between UCO module and conventional process in China.

Lu, Lu January 2012 (has links)
UCO (Ultra Clean Oil) module, an innovative adaption of existing used rolling oil treatment in the Aluminum industry, is being studied for its potential market in China. In this article, conventional used rolling oil treatment process in China has been evaluated and compared with the UCO module in technical and economic aspects. This article also discusses the effect of these two processes on the environment. The UCO module presented in this article, has the potential to significantly reduce the impurities in the used rolling oil and also save the cost for the raw materials, manpower, maintenance and operation for more than 1,600,000 Kr a year. With the new ― state of art‖ equipment, the UCO module has less negative effect on the environment. The UCO module appears to be more efficient but profitability was found to be lower than the conventional process in China.
146

Storm Sampling to Assess Inclement Weather Impacts on Water Quality in a Karst Watershed: Sinking Creek, Watauga Watershed, East Tennessee

McCurdy, Porcha 01 May 2020 (has links)
Escherichia coli changes in Sinking Creek, an impaired water body in the Watauga watershed of northeast Tennessee, were assessed during storm events using water samples collected with ISCO automated samplers during eight storms at two locations. Turbidity and electrical conductivity (EC) data loggers were deployed in the creek, and dissolved oxygen (DO) was measured in situ to test the stream’s water quality and reaction to inclement weather. Cotton fabric was deployed at both locations and sent to an external lab to test for the presence of Optical Brighteners (OB), which are indicators of residential wastewater. E. coli and turbidity at the creek generally increased within 2.5 hours of a rain event, remaining above the single sample standard for several hours during the storm. At the spring, E. coli became elevated within 30 minutes of precipitation onset, but generally decreased below the standard during the event.
147

Assessing Machine Learning Models to Optimize Turbidity Removal in Water Treatment

Sprague, Caleb A. 14 May 2022 (has links)
No description available.
148

Stratigraphic Architecture and Depositional History of Laterally-accreted Channel Fills in the Lower Isaac Formation, Windermere Supergroup, British Columbia, Canada

Dumouchel, Iain January 2015 (has links)
Continental slope channels, which serve as the primary conduits for sediment transport into the deep marine, occasionally become sites of sediment deposition with excellent reservoir potential. Increasingly reported in the literature are subsurface channel fills exhibiting shingled seismic reflectors that are interpreted to have formed by lateral channel migration. In lower Isaac Formation channels inclined strata are observed but at a lateral scale that is far below industry-seismic detection. Distinctively these flat-based channels are filled with coarse-grained sandstone that transitions abruptly and obliquely upwards into thin, fine grained turbidites. Like rivers, lateral accretion in Isaac channels is interpreted to be the result of the interaction of inertial and pressure forces, but in highly turbulent, highly density-stratified turbidity currents. This resulted in the formation of two superimposed secondary circulation cells that caused enhanced erosion on the outer bank and preferential deposition of coarse-grained sediment along the inner bank.
149

Using Relevance Vector Machines Approach for Prediction of Total Suspended Solids and Turbidity to Sustain Water Quality and Wildlife in Mud Lake

Batt, Hussein Aly 01 May 2012 (has links)
Mud Lake is a wildlife refuge located in southeastern Idaho just north of Bear Lake that traps sediment from Bear River water flowing into Bear Lake.Very few water quality and sediment observations, if any, exist spatially in Mud Lake. Spatial patterns of sediment deposition may affect Mud Lake flows and habitat; prediction of those patterns should help refuge managers predict water quality constituents and spatial distribution of fine sediment.This will help sustain the purposes of Mud Lake as a habitat and migratory station for species. The main objective of the research is the development of Multivariate Relevant Vector Machine (MVRVM) to predict suspended fine sediment and water quality constituents, and to provide an understanding for the practical problem of determining the amount of data required for the MVRVM. MVRVM isa statistical learning algorithm that is based on Bayes theory.It has been widely used to predict patterns in hydrological systems and other fields. This research represents the first known attempt to use a MVRVM approach to predict transport of very fine sediment andwater quality constituents in a complex natural system. The results demonstrate the ability of the MVRVM to capture and predict the underlying patterns in data.Also careful construction of the experimental design for data collection can lead the Relevant Vectors (RVs is a subset of training observation which carries significant information that is used for prediction) to show locations of significant patterns. The predictions of water quality constituents will be of potential value to US Fish and Wildlife refuge managers in making decisions for operation and management in the case of Mud Lake based on their objectives, and will lead the way for scientists to expand the use of the MVRVM for modeling of suspended fine sediment and water quality in complex natural systems.
150

Estimating Total Phosphorus and Total Suspended Solids Loads from High Frequency Data

Jones, Amber Spackman 01 December 2008 (has links)
Frequently measured turbidity was examined as a surrogate for total phosphorus (TP) and total suspended solids (TSS) loads at two locations in the Little Bear River, Utah, USA. Using regression techniques, equations were developed for TP and TSS as functions of turbidity. The equations accounted for censored data, and additional explanatory variables to represent hydrological conditions were considered for inclusion in the equations. By using the resulting surrogate relationships with high frequency turbidity measurements, high frequency estimates of TP and TSS concentrations were calculated. To examine the effect of sampling frequency, reference loads were determined from the concentration records for two water years. The concentration records were artificially decimated to represent various frequencies of manual grab sampling from which annual loads were calculated and compared to the reference loads.

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