Desalination plants are becoming essential due to the limited water resources in order to reduce the pressure of high demand of freshwater in many countries in recent decades. A concerning problem associated with desalination plants is the high concentration brine which has high risk to marine environments. Inclined dense jets are commonly used to treat brine produced by desalination plants or in industrial outfall discharges. They are produced when the brine is discharged at an upwardly inclined angle through a pipe or a diffuser system. Previous studies have mainly focused on jets on a horizontal bottom. In the present study, the influence of sloped bottom is investigated by numerical simulations using a modified solver in OpenFOAM (pisoFoam). Four different Reynolds Averaged Navier Stokes (RANS) turbulence models (Realizable k-ε, Standard k-ε, RNG k-ε and Nonlinear k-ε were employed to assess the accuracy of the selected turbulence models in predicting the jet behavior. Jets of inclination angle of 30° with four different initial conditions (Froude number=15, 20, 25, 30) on three different bed slope angles (2°, 5°, 10°) in stagnant water were conducted. Although inclined dense jets of the discharge angel of 60° are more common in discharge systems, sometimes they cannot be used in shallow waters in order to prevent surface pollution. In such cases, a relatively small jet inclining angle can be used to prevent the surface pollution and as shown in this thesis, bed slope can enhance the brine mixing and dilution. The results showed that Realizable k-ε model is more accurate among the turbulence models studied herein. The dilution at the impact point can be estimated based on the Froude number and initial conditions. After the impact point, the slope did enhance the dilution of the plume compared to the horizontal bed. The dilution was thus affected by the slope and the dilution after the impact point on the slope appeared to be linearly related to the distance to the source. Besides, the slope could enhance the jet dilution up to 20% compared with the horizontal bed after the impact point.

No description available.

Runoff during the revegetation of roadsides can transport sediment and nutrients offsite, leading to surface water quality reductions. Two field experiments were conducted near Starkville, MS in 2011 and 2012 to evaluate the influence of N and P sources and rates, fertilization timing, and mulch type on vegetative establishment and nutrient and sediment runoff losses. Stainless steel runoff frames (0.75 x 2.0 m) were installed on 10% and 15% slopes for Experiment I and Experiment II, respectively. A bahiagrass (Paspalum notatum Flugge), tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.], sericea lespedeza [Lespedeza cuneata (Dum. Cours.) G. Don], and common bermudagrass [Cynodon dactylon (L.) Pers.] mixture was seeded within each frame during Experiment I. Crimson clover (Trifolium incarnatum L.) was added for Experiment II. Experiment I treatments consisted of 73.5 or 147 kg N ha-1 as 13-13-13, poultry litter, ammonium nitrate, stabilized urea, polymer coated urea, or diammonium phosphate. Experiment II treatments consisted of wheat straw and six hydromulches; paper fiber, wood fiber, wood/paper fiber blend, flexible growth medium (FGM), extended term-FGM (ET-FGM), bonded fiber matrix (BFM). Runoff from natural and simulated rainfall was analyzed for PO43--P, total P (TP), NH4+-N, NO3- -N, total N (TN), and total solids (TS). Experiment I results suggest the greatest N and P runoff losses occurred during the first runoff event following fertilization. Splitting 147 kg N ha-1 into two equal applications increased nutrient losses compared to one application. Application of organic plus inorganic P increased PO43--P in runoff compared to inorganic P alone. Experiment II results indicate straw was the most effective mulch for increasing vegetative establishment and limiting solids and nutrients in runoff. However, lack of fertilizer prill dissolution may have influenced nutrient runoff losses during dry conditions. The FGM, ET-FGM, and BFM mulch treatments were more effective than the paper, wood, and paper/wood fiber treatments in reducing solids and nutrients in runoff. It was apparent during both experiments that timing, intensity, and duration of rainfall events following fertilization have an influence on runoff losses. However, further research is needed to quantify the influence of those rainfall parameters.

Roofs are the single enclosure element common to artificial shelters constructed by all cultures in all climate regions. The hygrothermal performance of insulated, sloped, wood-framed roof assemblies has long been of interest to building scientists and building codes alike. Requirements for the ventilation of roof assemblies have been included in building codes for more than 50 years, however moisture problems still occur. Unvented roof assemblies have been suggested as an alternate and potentially superior solution. While unvented roofs have become relatively common in the warmer southern climates of North America, some technical issues remain unclear and the need exists for further study and demonstration of the hygrothermal performance of both ventilated and unvented roof assemblies in cold northern climates. This thesis seeks to address these issues through a review of existing literature, experience and industry practice, field investigation and measurement, analytical calculation and computer simulations.

Roofs are the single enclosure element common to artificial shelters constructed by all cultures in all climate regions. The hygrothermal performance of insulated, sloped, wood-framed roof assemblies has long been of interest to building scientists and building codes alike. Requirements for the ventilation of roof assemblies have been included in building codes for more than 50 years, however moisture problems still occur. Unvented roof assemblies have been suggested as an alternate and potentially superior solution. While unvented roofs have become relatively common in the warmer southern climates of North America, some technical issues remain unclear and the need exists for further study and demonstration of the hygrothermal performance of both ventilated and unvented roof assemblies in cold northern climates. This thesis seeks to address these issues through a review of existing literature, experience and industry practice, field investigation and measurement, analytical calculation and computer simulations.

No description available.

No description available.

In this thesis, the dynamic modeling of a wheelchair-human system is performed, and the effects of steering action and sudden slope changes along the path on the system stability are analyzed for different road and driving conditions. For the cases where the wheelchair system is unstable three methods are proposed for stability augmentation. This study is performed to improve the stability of the wheelchair system under varying road conditions so as to increase the limit of independency for wheelchair users and enhance their life quality. Two separate mathematical models are obtained for the wheelchair driven on constant sloped and changing sloped roads. Matlab Simulink models are constructed with the obtained mathematical models and control structure. The stability of the system is analyzed by case studies and it is seen that the system is unstable in some of these cases. Three methods are used for enhancement of the stability. One is the speed reduction via joystick module during steep turns, by which the speed of the wheelchair is reduced automatically for a safe steering, but the wheelchair follows the desired course. The second method is the use of a shape filter in order to obtain a less jerky response for the speed. As a final method, the center of mass of the wheelchair-human system is shifted gently in a controlled manner to the side where the reaction force on the wheels decreases.

The aim of my project was revitalization of the selected section of the watercourse. The subject of revitalizing modifications is the reduction slope of the bottom, supplemented by a catchment grades and a boulder slip. Other modification is reducing the tendency of banks and new draft of accompanying vegetation.

This final thesis is about the object of civic amenities. This office building have three levels above ground and basement under the whole area of building. The structural system of the object is reinforced concrete frames in both directions. Object is designed as building with two wings and the middle narrowed part for communication. Building has flat roof and shelter for parking cars with one part used as terrace for café. Object is built on slightly sloped ground from south to north.