Study of Qattara depression and its hydropower potential

The Qattara Depression is a very interesting geomorphic feature that has been suggested to be used for hydropower production. This research will investigate hydrological elements affecting the water balance of the Qattara Depression region. Climatic data obtained from weather stations surrounding the region will be used in the investigation, as climatic factors such as rain and water evaporation would affect the mass balance equation. Then environmental and economic implications of such a project will also be studied. Many schemes have been suggested in the past for the project. All these schemes are compared economically in this work for the first time as far as the author knows. And the model employed investigates elements that had not been previously investigated. The outward seepage calculation and its affect on the plant lifetime is included in the model and the economic study and also its environmental impacts are checked. The effect of the channel flow of water before reaching the lowest point of the depression as it was not previously included in the evaporation calculation, but it is investigated in this model. Also a detailed study of the effect of the salinity increase of the water in the depression is investigated. The way all this enabled is by using data from three weather stations near Qattara Depression (Siwa, Dabaa, Wadi El Natroon) and the data is used on a monthly bases to calculate the evaporation that would occur as it would be used in the mass balance equation that includes the evaporation, that is affected by the progressive salinity increase, the inward and outward seepage, the rainfall, and the inflow from the sea. Using that calculation the progressive increase in the surface level in the depression is always obtained and the best design and economic study is planned accordingly

Rectal impalement injury through the pelvis, abdomen and thorax

Peer reviewedPublisher PD

Dynamics of rotors incorporating squeeze film dampers

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1988.Includes bibliographical references.by Aly El-Shafei.Ph.D

Evaluating Tomato Performance: A Novel Approach of Combining Full and Deficit Irrigation with Saline Water

The tomato is a vital component of agriculture and is the second-most important vegetable globally. Maintaining a high tomato production requires both water quality and quantity. Water-scarce regions like Saudi Arabia still lack an understanding of the impact of deficit irrigation and the use of a blend of saline and freshwater, especially their nuanced impact across growth stages. The purpose of this study was to evaluate the effects of six different irrigation amounts: full irrigation with 100% ETc (FI), regulated deficit irrigation with 60% ETc (DI), and deficit irrigation with 60% ETc, except for the initial (DI-int), development (DI-dev), mid-season (DI-mid), and late-season (DI-lat) stages. This was performed with three different water qualities: fresh (FW), saline (SW), and fresh-saline blend (1:1) (MW) water. FW and MW enhanced the growth, physiology, morphology, yield, and quality, while SW had the lowest values. DI reduced these parameters and lowered yields by 13.7%, significantly improving water use efficiency (WUE) by 44% and fruit quality. DI-mid or DI-lat slightly improved yields while remarkably decreasing WUE and fruit quality. DI outperforms deficit irrigation in all growth stages except one, and countries with limited freshwater resources can benefit from a mix of fresh and saline water with a 60% ETc deficit irrigation, resulting in greater water savings

Evaluation of early changes of cartilage biomarkers following arthroscopic meniscectomy in young Egyptian adults

AbstractBackgroundThe metabolic imbalance in the articular cartilage following meniscectomy includes an increase in cartilage degradation with an insufficient reparative or anabolic response resulting in structural, biochemical and mechanical changes that can progress from pre-clinical, to pre-radiographic, to radiographic damage of the joint.PurposeTo evaluate combinations of imaging and biochemical biomarkers for cartilage breakdown, synthesis and quantity in the early period of post-arthroscopic meniscectomy.Subjects and methodsTwenty young adults (three of them were females) who underwent unilateral arthroscopic partial meniscectomy were evaluated. The patients had a mean age of 32.5years (range, 24–39), mean BMI of 28.5kg/m2 (range, 24–34). Preoperative and six months postoperative US and MRI-based markers (cartilage thickness and volume, respectively) were quantified for medial and lateral tibio-femoral compartments for both knees. Preoperative, three and six months postoperative biochemical markers serum assays were measured; COMP and Col II (cartilage matrix breakdown) and PIICP (cartilage synthesis). These three markers were measured in an age, sex and BMI matched twenty healthy subjects for comparison.ResultsThe meniscectomized knees had significantly lower total knee cartilage volume, P<0.05 but non-significant mean thickness than the intact contralateral knees. Among the individual biochemical markers, PIICP had the highest significant diagnostic accuracy quantified as the area under the receiver-operator characteristics curve (AUC) of 0.75 (95% confidence interval: 0.509–0.912) higher than all others, P<0.05 to distinguish subjects with progressive cartilage loss from non-progressors. Diagnostically, ratio of COMP and Col II to PIICP scored AUC of 0.90 (0.69–0.98, higher than PIICP: P=0.0001). For prediction of cartilage loss, none of the individual markers could be used.ConclusionCartilage volume loss by MRI combined with changes in cartilage matrix turnover detected by molecular biomarkers may reflect the initial changes associated with cartilage degeneration that account for early OA