Performance of a Solar Chimney Under Egyptian Weather Conditions: Numerical Simulation and Experimental Validation

High solar radiation and ambient temperature, and large desert in Egypt are excellent conditions to install efficiently solar chimney power plants there. Therefore this research aimed to develop a validated mathematical model and governing equations of solar chimney. It is proposed to improve the performance of solar chimney under effects of various parameters, and study of possibility of installing solar chimney in Egypt. The mathematical simulation of the solar chimney has been developed including all its performance parameters, dimensions (of collector, chimney and turbine) and the metrological data; which were considered as inputs of the simulation program. A comparison between the mathematical and experimental performance has been investigated to validate the mathematical simulation. The mathematical model has been used to predict the performance of the solar chimney power plant over a year in Egypt. It is used to study of effects of geometrical parameters, and investigate possibility of the optimum geometrical dimensions. It is obtained that there is in fact no optimum physical size for such plants without considering the economical constraints. The chimney height has a significant effect in the chimney performance. Visualizing of annual performance of the solar chimney would seem to be essentially a power generator in Egypt if it installed in a large scale.Key words: Solar chimney; Numerical simulation; Annual performance; Experimental validation; Optimizatio

Far‐field lithospheric deformation in Tibet during continental collision

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95177/1/tect2049.pd

Sclerodactyly and Diabetic Complications among Egyptian Adolescent Type 1 Diabetic Patient

BACKGROUND: One of the common complications of diabetic patients is sclerodactyly which is considered as a part of limited joint mobility. AIM: To assess sclerodactyly in adolescent type 1 diabetics and to detect its relation to other diabetic complications. METHODS: Sixty-three diabetics and 60 controls were studied. Clinical, laboratory assessment, ultrasonography of the skin, carotid artery intima-media thickness (cIMT) & renal colour duplex were done for all participants. RESULTS: Sclerodactyly was positive in 12 (19%) of diabetics. Patients with sclerodactyly had a significantly thickened skin compared to patients without sclerodactyly and controls, P = 0.0001. Male diabetics had significantly thickened skin (p = 0.0001). Diabetic patients with sclerodactyly had significant higher systolic blood pressure (p = 0.03), cholesterol (p = 0.05) and triglyceride (p = 0.004) and lower HDL-c (p = 0.04). Skin thickness had a significant positive correlation with age of diabetic patients (p = 0.02), waist/height ratio (p = 0.04), glycosylated hemoglobin (p = 0.03), albumin/creatinine ratio (p = 0.03), and cIMT (p = 0.03). CONCLUSION: Ultrasound easily diagnoses sclerodactyly. Diabetic patients had a high prevalence of sclerodactyly with increased macrovascular and microvascular complications. Sclerodactyly may be a marker for diabetic vascular complications. Frequent follow up of diabetic patients for early detection of sclerodactyly in uncontrolled diabetic patients is recommended. It could be an alarming sign for microalbuminuria, hypertension, hyperlipidaemia and atherosclerosis

Demonstration of Near-Real-Time Accounting at the Agns Barnwell Plant

Near-real-time nuclear materials accounting is being demonstrated in a series of experiments at the Allied-General Nuclear Services Barnwell Nuclear Fuels Plant. Each experiment consists of operating the second and third plutonium cycles continuously for 1 week using uranium solutions. Process data are collected in near-real time by the AGNS computerized nuclear materials control and accounting system, and the data are analyzed for diversion using decision analysis techniques developed and implemented by Los Alamos. Although the measurement system primarily consists of process control measurements that have not been optimized for near-real-time accounting, the results of a series of diversion tests show that diversion and unexpected losses from the process area can be detected

Myocarditis: an expected health hazard associated with water resources contaminated with Coxsackie viruses type B

Enteroviruses, especially Coxsackie B viruses (CBVs), are responsible for approximately 50% of cases of viral myocarditis. In the present study, serum samples (160) were collected from acute myocarditis patients at different age groups and 104 samples of the same age groups as a control. Cholesterol, LDH, CPK, and GOT were measured for all serum samples (264). Also, to study the source of virus transmission, 72 water and 72 wastewater samples were collected from water and wastewater treatment plants at intakes and outlets. Water and wastewater samples were concentrated by filtration through Zeta-plus filter cartridges and reconcentrated by the PEG-6000 precipitation method. Serum, water, and wastewater samples were inoculated in BGM cells for three successive passages. RT -PCR with enterovirus primers was carried out directly for serum samples and for 1st and 3rd cell culture passages. The positive samples were used for neutralization assay using anti-CBV sera pool to determine the CBV followed by neutralization with separate antisera. The results showed that 50 (31.25%) serum samples from acute myocarditis patients and two (1.4%) samples from the controls were positive for enterovirus RT -PCR. For water and wastewater samples enteroviruses were present in 63.8% and 8.3% for intake and outlet of water treatment plants and, 66.6% and 47.2% for intake and outlet of wastewater treatment plants, respectively. The level of CBV serotypes was varied where CBV3 was dominant for all age groups of myocarditis patients and CBV2 and CBV5 were also detected while CBV2 was the main CBV in water samples and CBV2, 3 and 5 were detected in wastewater samples. The integration of cell culture-PCR reduces the time required for virus detection and enhances the sensitivity of the test

Copeptin as a Biomarker of Atherosclerosis in Type 1 Diabetic Patients

AIM: To evaluate copeptin as an early marker of atherosclerosis in adolescent type 1 diabetics. METHODS: Sixty-two type 1 diabetic patients and 50 healthy volunteers were enrolled in the study. Serum copeptin, glycosylated haemoglobin (HbA1c), lipid profile, oxidised low-density lipoprotein (OxLDL), urinary albumin/creatinine ratio, carotid intimal medial thickness (cIMT), aortic intimal medial thickness (aIMT) and resistivity index were assessed for all participant in the study. RESULTS: HbA1, albumin/creatinine ratio, lipid profile, OxlDL, copeptin, cIMT and aIMT were significantly higher in diabetic patients. Copeptin was higher in patients with positive cIMT and aIMT. Copeptin correlated with cIMT and aIMT. Stepwise multiple regression analysis found that copeptin correlated with aIMT. ROC curve showed that copeptin had 100 % specificity with aIMT and cIMT and 95.2 and 60,7 sensitivity with aIMT and cIMT respectively. CONCLUSION: Copeptin can be used as a marker for early detection of atherosclerosis of type 1 diabetic patients

Nitric Oxide Gene Polymorphism is a Risk Factor for Diabetic Nephropathy and Atherosclerosis in Type 1 Diabetic Patients

AIM: To assess the risk factor for diabetic atherosclerosis nephropathy and diabetic nephropathy in type 1 diabetic patients. PATIENTS AND METHODS: Thirty healthy volunteers age and sex-matched and Sixty-five type 1 diabetic patient were in rolled in the study. The mean age of patients was 17.99 ± 2.59 years, mean age of onset of diabetes was 7.00 ± 3.28 years, mean duration of diabetes was 10.91 ± 3.54 years. Glycosylated sex-matched (HbA1c) was assessed in blood samples, serum lipid profile was determined, and serum level of oxidised low-density lipoprotein (OxLDL), and nitric oxide was evaluated by enzyme-linked immunosorbent assay (ELISA) technique. Nitric oxide 894G > T genotype was analysed by (PCR-RFLP) method and confirmed by Sequencing. Assessment of the albumin / creatinine ratio was done in urine samples. Renal Doppler and Carotid intima-media thickness (cIMT) via ultrasound was also performed. RESULTS: OxLDL, lipid profile, albumin/creatinine ratio, cIMT and resistivity index were significantly higher in diabetic patients while nitric oxide was significantly lower. Nitric oxide genotype shows no significant difference between diabetic’s patients and controls. Diabetic patients with homozygous NO had a significantly lower serum level of Nitric oxide, a significantly higher OxLDL, albumin / creatinine ratio and lipid profile. CONCLUSION: diabetic patients are liable for the occurrence of early diabetic nephropathy and atherosclerosis as a result of the presence of low level of nitric oxide. Nitric oxide gene polymorphism 894G > T in diabetic patients is a risk factor for diabetic nephropathy and atherosclerosis

Osteopontin for Early Detection of Microvascular and Macrovascular Type 1 Diabetic Complication

AIM: To evaluate the relationship between osteopontin and diabetes complication in type 1 diabetic patient. PATIENTS AND METHODS: Seventy types 1 diabetic and 60 healthy volunteers were studied. Full history, examination, laboratory tests of glycosylated haemoglobin (HbA1c), serum lipids {cholesterol, triglyceride (Tg), high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein – cholesterol (LDL-c)}, oxidised low-density lipoprotein (OxLDL), Osteopontin and urinary microalbuminuria (albumin/creatinine ratio) were done. Image study in the form of a carotid intimal medial thickness (cIMT) and aortic intimal medial thickness (aIMT), renal doppler for resistivity index was also done for all participant included in the study. RESULTS: Urinary albumin/creatinine ratio, lipid profile, osteopontin, cIMT and aIMT were higher in people with diabetes. Osteopontin was higher in people with diabetes with positive microalbuminuria and cIMT. Systolic blood pressure, microalbuminuria and cIMT had a positive correlation with osteopontin in people with diabetes. Stepwise multiple regression analysis showed that osteopontin had a significant correlation with cIMT. Receiver operating characteristic (ROC) curve showed that the cut off value of Osteopontin for detection of cIMT was > 60 with a specificity of 100% and sensitivity 80.5%, while that of albumin/creatinine ratio was > 64 with a specificity of 66.7 and sensitivity of 92.3. CONCLUSION: Osteopontin is higher in type 1 diabetics and is useful for early detection of diabetic microvascular and macrovascular complication