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Alternate Bars Under Steady State Flows: Time of Development and Geometric CharacteristicsBoraey, Ahmed 31 March 2014 (has links)
This thesis concerns the development of alternate bars under steady state flows. The movable bed is flat at the beginning of the experiment; the bars reach their equilibrium or developed state at the time Td. The thesis has two objectives. The first is to introduce new equations for the geometric characteristics, namely height and length, of alternate bars at the fully developed stage, and to evaluate them against the existing equations. The second objective is to present the results of two series of experiments carried out to characterize the process of development of alternate bars and obtain estimates of their time of development. The data resulting from these experiments are intended as a foundation for future work towards the establishment of a predictive equation for the development time of alternate bars.
The new equations for bar height and length rest on dimensional considerations and all the available data. Bars produced under rough turbulent and transitional flows are treated separately. The proposed equations are found to consistently give more accurate estimates of alternate bar dimensions than existing equations.
The experiments to quantify the time of development of alternate bars are carried out in the 21 m long, 0.76 m wide sediment transport flume of the Queen’s Coastal Engineering Laboratory. In addition to providing estimates of the time of development of alternate bars, these experiments reveal aspects of the process of development of alternate bars that had not been reported previously. In particular, they show that, all other conditions being the same (including the sediment transport capacity of the initial flow), the more pronounced alternate bars formed under shallower flows develop faster than less pronounced bars formed under deeper flows.
The findings of this study highlight the fact that the previously unexplained wide variation in alternate bar dimensions is related to the plotting position of the data point in the alternate bar existence region of Ahmari and da Silva (2011). This study also sheds light on the evolution and development of alternate bars, which establishes a strong foundation for future studies on the topic. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2014-03-30 16:27:07.025
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Stanovení klidového energetického výdeje u osob s obezitou / Assessment of the Resting Energy Expenditure in Obese IndividualsSadílková, Aneta January 2017 (has links)
Introduction: Weight loss programs are based on inducing a negative energy balance by decreasing energy intake while increasing energy expenditure. Energy needs of obese patients are difficult to determine. The value of resting energy expenditure, as the largest component of the energy needs, is usually calculated to asses an adequate energy intake for obese patient. In clinical practice, predictive equations are most commonly used for this purpose, because of their simplicity, although many clinical studies have shown that in obese individuals they may generate errors large enough to impact the outcome of treatment. It leads to the prescription of an inadequate diet that does not meet the criterion of long-term sustainability. Objective: The aim of the thesis is to compare the values of resting energy expenditure (REE) measured by indirect calorimetry with values calculated with Harris-Benedict predictive equation in a selected group of obese individuals. Methods: The sample includes 38 subjects, 28 women and 10 men, patients of the General University Hospital in Prague. The average age is 48 ± 11,71 years, the mean BMI is 42,88 ± 9,09 kg/m2 . For each subject, resting energy expenditure was measured by indirect calorimetry and calculated by the Harris-Benedict predictive equation. Indirect...
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Soil Salinity Abatement Following Hurricane IkeMueller, Ryan 2012 August 1900 (has links)
In September 2008 Hurricane Ike hit the Texas Gulf Coast with a force stronger than the category 2 storm at which it was rated. With a 3.8 m (12.5 ft) storm surge, the agricultural industry in the area was devastated. The goal of this research was to determine the length of time required to reduce the salt levels brought by the storm surge to near pre-hurricane levels. To do this, four sets of samples were taken across two years and analyzed for salinity using the saturated paste extract method.
The initial salt levels in November 2008 had an electrical conductivity (ECe) of the inundated soils as high as 26.7 dS/m. Fifty-four percent of the soils sampled in the 0-15 cm horizons and 9% in the 15-30 cm horizons of the edge area had an ECe >= 4 dS/m. In the surge area 79% of the soils sampled in the 0-15 cm horizons and 30% in the 15-30 cm horizons had an ECe >= 4 dS/m.
In April 2009, 38% of the soils sampled in the 0-15 cm horizons and 13% in the 15-30 cm horizons of the edge area had an ECe >= 4 dS/m. In the surge area 71% of the soils sampled in the 0-15 cm horizons and 39% in the 15-30 cm horizons had an ECe >= 4 dS/m.
By December 2009, none of the soils sampled in the edge area had an ECe >= 4 dS/m. In the surge area 21% of the soils sampled in the 0-15 cm horizons and 33% in the 15-30 cm horizons had an ECe >= 4 dS/m. By October 2010, all soils sampled had leached sufficient salts to be classified as non-saline to very slightly saline soils.
Utilizing the November 2008 data set, 28 random samples were selected for exchangeable Na percent (ESP) in order to develop the ESP-SAR (Na adsorption ratio) predictive equation, ESP= 1.19(SAR)^0.82. The SAR-ESP relationship is statistically significant (95% confidence level), with a correlation coefficient of 0.964 (df=26).
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