Modeling of hydrodynamics and sedimentation in a stratified reservoir: Tahtalı Reservoir, İzmir

Thesis (Master)--Izmir Institute of Technology, Civil Engineering, Izmir, 2008Includes bibliographical references (leaves: 82-88)Text in English; Abstract: Turkish and Englishxiii, 88 leavesThe main goal of this study was to investigate the hydrodynamics of a stratified reservoir for different flow and weather conditions through numerical modeling. This study also investigated the effects of selective withdrawal, climate change, and sediment deposition on hydrodynamics. A three-dimensional numerical model, Environmental Fluid Dynamics Code (EFDC) has been selected in the present study to model the hydrodynamics in the lake. The study site was selected as the main pool of Tahtali Reservoir providing 40% of the water used in the city of zmir (Population: 3.4 million by 2000). Applied numerical model was validated by monthly observations of water velocity and temperature profiles. Field measurements were performed from July 2006 to September 2007 in the lake and in two rivers (aal and Tahtali). The water velocity measurements in the lake were made using a 1.5-MHz acoustic Doppler current profiler. For water temperature and quality measurements, a hand-held water quality meter with a depth sensor were used for both lake and river measurements. Furthermore, a weather station was set up by the lake in order to collect accurate data for wind conditions in the study site.The numerical model predicted the observed velocity profiles and temperature time series satisfactorily. Possible reasons for discrepancies were investigated. Numerical model results indicated that water velocities were strongly dominated by the wind data and correct measurement of wind stress on the lake surface is necessary for accurate prediction of velocities in the water column. Withdrawal of the water at the bottom outlet was found to be the most effective choice encouraging the mixing of the water column. Possible climate change impacts modeled numerically indicated that the thermocline depths were lowered in the water column causing the deterioration of water quality. Sedimentation thickness was estimated via numerical modeling and the long term erosion rate was calculated by USLE method. Modeling the sedimentation zones provided valuable information on the capacity of the reservoir. The results of this study can be used to guide the further investigations in the lake including modeling of water quality for better management practices

Results of Our Patients with Proximal Humerus Fractures above 60 Years of Age, in which We Applied Osteosynthesis with Locked Humerus Plate

INTRODUCTION: There is controversy about the treatment of proximal humeral fracture (PHF) in elderly patients. Surgery should be considered especially for comminuted and advanced displacement fractures. Due to factors such as osteoporosis caused by advanced age, locked proximal humeral plates (LPHP) with good bone involvement are preferred. We examined the results of the LPHP that we applied for PHF over 60 years. METHODS: Patients with PHF over the age of 60 were included in the study. Patients underwent open reduction with a deltopectoral incision and osteosynthesis with a LPHP. Patients are followed up for at least 1 year radiologically and clinically. After the first year, our patients were evaluated according to the Constant-Murley shoulder score (CMSS) and complications were followed up. RESULTS: 31 patients with PHF who were operated on by us were included in our study (25 females,6 males). The mean age is 71.22(62-87). Our patients; According to the Neer classification, 1 has 1-part,13 has 2-part,12 has 3-part, 5 has 4-part and 3 has fracture-dislocations. Mean follow-up time: 13.9(12-18) months. Average union time: 13.55 weeks(12-20). The mean CMSS was found to be 49.74(23-98). There was no significant difference between the CMSS of patients above and below 70 years. No significant difference was found between the CMSS of Neer type 1,2 and 3,4 patients. DISCUSSION AND CONCLUSION: Since locked humeral plate application in patients with PCC over 60 years is prone to complications and poor functional results,we think that it would be appropriate to plan the surgeries accordingly by considering alternative treatment options for these patients

Modeling of hydrodynamics and sedimentation in a stratified reservoir: Tahtalı Reservoir, İzmir

Thesis (Master)--Izmir Institute of Technology, Civil Engineering, Izmir, 2008Includes bibliographical references (leaves: 82-88)Text in English; Abstract: Turkish and Englishxiii, 88 leavesThe main goal of this study was to investigate the hydrodynamics of a stratified reservoir for different flow and weather conditions through numerical modeling. This study also investigated the effects of selective withdrawal, climate change, and sediment deposition on hydrodynamics. A three-dimensional numerical model, Environmental Fluid Dynamics Code (EFDC) has been selected in the present study to model the hydrodynamics in the lake. The study site was selected as the main pool of Tahtali Reservoir providing 40% of the water used in the city of zmir (Population: 3.4 million by 2000). Applied numerical model was validated by monthly observations of water velocity and temperature profiles. Field measurements were performed from July 2006 to September 2007 in the lake and in two rivers (aal and Tahtali). The water velocity measurements in the lake were made using a 1.5-MHz acoustic Doppler current profiler. For water temperature and quality measurements, a hand-held water quality meter with a depth sensor were used for both lake and river measurements. Furthermore, a weather station was set up by the lake in order to collect accurate data for wind conditions in the study site.The numerical model predicted the observed velocity profiles and temperature time series satisfactorily. Possible reasons for discrepancies were investigated. Numerical model results indicated that water velocities were strongly dominated by the wind data and correct measurement of wind stress on the lake surface is necessary for accurate prediction of velocities in the water column. Withdrawal of the water at the bottom outlet was found to be the most effective choice encouraging the mixing of the water column. Possible climate change impacts modeled numerically indicated that the thermocline depths were lowered in the water column causing the deterioration of water quality. Sedimentation thickness was estimated via numerical modeling and the long term erosion rate was calculated by USLE method. Modeling the sedimentation zones provided valuable information on the capacity of the reservoir. The results of this study can be used to guide the further investigations in the lake including modeling of water quality for better management practices

Isı borusu ağları yardımıyla elektronik paketlerden ısı atımı ve bunun döner tablalara uygulanması.

An electronics package on a rotary platform including two components with 600 W, one component with 350 W and one small component with 70 W heat dissipation rates (1620 W total heat load) is numerically and experimentally investigated under steady state conditions. In order to avoid rotary joints and to reduce the costs of design, maintenance and production, the thermal management solution for the heat dissipation is entirely placed on the rotary platform. The thermal management solution includes heat sinks attached to the vertical side surfaces of the platform and heat pipes connected to heat sinks. The heat dissipating components are connected to the heat sinks with heat pipes. The heat sinks are cooled by forced convection with high power fan assemblies. Two different fin configurations are considered. One of them is a pin fin design and the other one is a plate fin covered with duct design. The thermal management systems are numerically modeled and then one of the numerical models is validated with a set of experiments. The validated model is used for the optimization of the system and as a demonstration of feasibility of the heat pipes. The optimization parameters are the heat pipe locations, their connections to the heat sinks and geometrical properties of the heat sinks. The optimization criteria are to maintain nearly uniform temperature distributions on the heat sinks and to keep critical components below their thermal shut-down points. The constraints are the lengths of the standard heat pipes and the limited options to bend the heat pipes due to their fragile structures. The success of the system is that it can keep the hot spot temperatures below the allowed maximum temperature of 120 oC even for the case of 50 °C ambient air temperature. The limitation of 120 oC working temperature comes from the thermal shut-down limits of the components in the electronics package.M.S. - Master of Scienc

Using numerical models and acoustic methods to predict reservoir sedimentation

This study draws on drainage basin hydrography, numerical modeling and geographic information system (GIS) techniques in concert with dual frequency echo sounder data to estimate sediment thickness when initial surveys are unavailable or inaccurate. Tahtali Reservoir (Turkey), which provides 40% of water supply to the city of Izmir, was selected as the study site. Deposition patterns within the whole lake were estimated with a 3-D hydrodynamic and sediment transport model applied to Tahtali Reservoir. The numerical model simulated lake response to wind forcing and inflows and/or outflows and was used to describe sediment deposition patterns resulting from the erosion of soils quantified by the implementation of Universal Soil Loss Equation (USLE) to the whole watershed. Surveying of the lake via dual frequency (28/200 kHz) echo sounder system revealed the current bathymetry, and sediment thickness was estimated from the difference of depths measured by the dual frequency sounder along surveyed transects. These results were compared to the modeled sedimentation thicknesses and to preliminary estimates of watershed sediment yield estimated by USLE. Results of this study can be used for further water quality studies and for long term management plans.TÜBİTAK project No: 104Y323 and European Commission project No: 28292 (RESTRAT

Triterpene saponins from Nigella sativa L.

Three known triterpene glycosides were isolated from the MeOH extract of dried and powdered seeds of Nigella sativa. The structures of the compounds were established as 3-O-[$\beta$-D-xylopyranosyl-$(1\rightarrow 3)$-$\alpha$- L-rhamnopyranosyl-($1\rightarrow 2$)-$\alpha$-L-arabinopyranosyl]-28-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 4)-$\beta$-D-glucopyranosyl- (1\rightarrow 6)-$\beta$-D-glucopyranosyl]-hederagenin (1), 3-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 2)-$\alpha$-L-arabinopyranosyl]- 28-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 4)-$\beta$-D-glucopyranosyl-(1\rightarrow 6)-$\beta$-D-glucopyranosyl]-hederagenin (2), and 3-O-[$\beta$-D-xylopyranosyl-(1\rightarrow 3)-$\alpha$-L-rhamnopyranosyl-(1\rightarrow 2)-$\alpha$-L-arabinopyranosyl] -hederagenin (3) by means of chemical and spectral methods. Compound 2 was isolated for the first time from the genus Nigella.Three known triterpene glycosides were isolated from the MeOH extract of dried and powdered seeds of Nigella sativa. The structures of the compounds were established as 3-O-[$\beta$-D-xylopyranosyl-$(1\rightarrow 3)$-$\alpha$- L-rhamnopyranosyl-($1\rightarrow 2$)-$\alpha$-L-arabinopyranosyl]-28-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 4)-$\beta$-D-glucopyranosyl- (1\rightarrow 6)-$\beta$-D-glucopyranosyl]-hederagenin (1), 3-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 2)-$\alpha$-L-arabinopyranosyl]- 28-O-[$\alpha$-L-rhamnopyranosyl-(1\rightarrow 4)-$\beta$-D-glucopyranosyl-(1\rightarrow 6)-$\beta$-D-glucopyranosyl]-hederagenin (2), and 3-O-[$\beta$-D-xylopyranosyl-(1\rightarrow 3)-$\alpha$-L-rhamnopyranosyl-(1\rightarrow 2)-$\alpha$-L-arabinopyranosyl] -hederagenin (3) by means of chemical and spectral methods. Compound 2 was isolated for the first time from the genus Nigella