The evacuated tube solar collector ETC is studied intensively and extensively by experimental and
theoretical works, in order to investigate its performance and enhancement of heat transfer, for Baghdad climate
from April 2011 till the end of March 2012. Experimental work is carried out on a well instrumented collector
consists of 16 evacuated tubes of aspect ratio 38.6 and thermally insulated tank of volume 112L. The relation
between convective heat transfer and natural circulation inside the tube is estimated, collector efficiency, effect of
tube tilt angles, incidence angle modifier, The solar heating system is investigated under different loads pattern (i.e
closed and open flow) to evaluate the heat loss coefficient from tank and tubes, test the collector with various
aspect ratios (32.9 and 27.2). The enhancement in collector performance is studied by using two reflectors (Flat
Plate and Curved Plate) and nanofluid (Water-AL2O3).Theoretical work is run by software (Fluent 6.3), to compute
the velocity and temperature profiles within the tube, for different tube diameters, effect of tube junction angle and
stagnant region in the bottom of the evacuated tube. The experimental results shows that the heat loss coefficient
for tube is W/m2.K and for tank is W/m2.K, the maximum collector temperature is 79°C in winter and
99°C in summer, while that belong to nanofluid collector is 99°C in winter. The best tilted angle (optimum) of
evacuated tube is 41° annually. The collector efficiency increased when using nanofluid of (1, 0.6, 0.3)% volume
fraction as(28.4, 6.8, 0.6)% respectively. The efficiency decreases as (33, 62)% when decreasing tube aspect ratio
from 38.6% to 32.9% and 27.2% respectively. An increase of (16.9 and 7.08)% in collector efficiency is obtained
when using curved and flat plate reflectors respectively. From simulation the best junction angle of the tank is
22.5°. The stagnant region is influenced with changing heat flux, tilted angle and aspect ratio.
In low-latitude areas less than 10° in latitude angle, the solar radiation that goes into the solar still increases as the cover slope approaches the latitude angle. However, the amount of water that is condensed and then falls toward the solar-still basin is also increased in this case. Consequently, the solar yield still is significantly decreased, and the accuracy of the prediction method is affected. This reduction in the yield and the accuracy of the prediction method is inversely proportional to the time in which the condensed water stays on the inner side of the condensing cover without collection because more drops will fall down into the basin of the solar-still. Different numbers of scraper motions per hour (NSM), that is
... Show MoreThe degradation performance of aqueous solution of pesticide Alachlor has been studied at solar pilot scale plant in two photocatalytic systems: homogeneous photocatalysis by photo-Fenton and heterogeneous photocatalysis with titanium dioxide. The pilot scale system included of compound parabolic collectors specially designed for solar photocatalytic applications, and installed at University of Baghdad, Department of Environmental Engineering back yard. The influence of different concentrations, H2O2 (200-2400 mg/l), Fe+2(5- 30 mg/l) and TiO2 (100-500 mg/l) and their relationship with the degradation efficiency were studied.
The COD removal efficienc
... Show MoreWe investigated at the optical properties, structural makeup, and morphology of thin films of cadmium telluride (CdTe) with a thickness of 150 nm produced by thermal evaporation over glass. The X-ray diffraction study showed that the films had a crystalline composition, a cubic structure, and a preference for grain formation along the (111) crystallographic direction. The outcomes of the inquiry were used to determine these traits. With the use of thin films of CdTe that were doped with Ag at a concentration of 0.5%, the crystallization orientations of pure CdTe (23.58, 39.02, and 46.22) and CdTe:Ag were both determined by X-ray diffraction. orientations (23.72, 39.21, 46.40) For samples that were pure and those that were doped with
... Show MoreBackground: Directly observed therapy-short course (DOTS) had been adopted by World Health Organization (WHO) as hopeful strategy for treatment of tuberculosis (TB) since early nineties. Iraqi health authorities started DOTS implementation since 2001 in Baghdad. Coverage expanded gradually till 100% in 2004. War and unstable security condition hit Iraq since March 2003. Objective: The objective of this study was To evaluate the DOTS implementation program in Baghdad in different periods including 2 unstable periods for proper assessment of war and instability on treatment of TB. Patients and methods: This study had been conducted in Baghdad during four different periods (before and during 2003 war, after war; without and with DOTS). Dire
... Show MoreLasmiditan (LAS) was formulated as a nanoemulsion based in situ gel (NEIG)with the aim of improving its oral bioavailability via application intranasally. The solubility of LAS in oils, emulsifiers, and co-emulsifiers was determined to identify nanoemulsion (NE)components. Phase diagrams were constructed to identify the area of nanoemulsification. LAS NE was formulated using the spontaneous nanoemulsification method. Four NEs (F19, F24, F31, and F34) containing 7-15 % oleic acid (OA) as an oily phase, 40-55% labrasol (LR), and transcutol (TC) as emulsifier mixture at (1:1), (2:1), (3:1), and (1:2) ratio with 30-53 % (w/w) aqueous phase, having suitable optical transparency of 95–98%, globule size of 104-140 nm and polydisper
... Show MoreThis paper suggesting a new modern method to evaluate the performance of hotel industry at Jordan instead of the classical method used by the industry and that is Bench Marking , this method can be done by comparing the performance of hotel industry at two serial years which helps in calculating a standard performance .
The industry can use this standard to identify the variance, which make the evaluation of performance easier and support the efforts to develop the hotel industry at all levels and enable to give high quality services to customers.
The study believed that this situation would not be achieved unless the hotel industry will app
... Show MoreSickle cell disease (SCD) comprises an inherited blood disorder that is life long and affects many people globally. In spite of the development in treatment, SCA is a considerable cause of mortality and morbidity. The present study tries to assess the role of leukocytes represented by β integrin(CD18) and platelets and their productivity in the pathogenicity of disease during the steady state and crisis in comparison with the healthy as-control group, SCD patients (15) enrolled during crisis and steady state (follow up) showed a significant increase in leukocytes and platelets cells productivity during crisis when compared to the steady state and in the steady state when compared to the healthy control group . In this study, SCD patho
... Show MoreSilybum marianum, from which silymarin (SM) is extracted, is a medicinal herb. In the Biopharmaceutics Classification System, it is of the class II type, meaning it is almost completely insoluble in water. It has a number of therapeutic properties, including anti-inflammatory as well as properties that promote wound healing.
This research target is to promote the dissolution and solubility of SM by employing a technique called solid dispersion and then incorporating the formula of solid dispersion into a topical gel that can be used for wound healing.
Solid dispersion is a technique used to enhance solubility and dissolve pharmaceuticals that are not water-soluble. This method is widely used because of its low cos
... Show MoreBackground: Acute coronary syndrome (ACS) is a common disease, and a major determinant of morbidity and mortality in all races. The pleiotropic effects of the receptor activator of nuclear factor-kappa B ligand (RANKL) such as modulation of cell survival, mineralization and inflammation, make it an interesting candidate mediator in the progression and destabilization of atherosclerotic lesions.Objectives: This study was performed to investigate the role of RANKL in the pathogenesis of ACS.Methods: The levels of RANKL were measured by ELISA method in sera of 60 ACS patients, 31 patients with unstable angina (UA) and 29 patients with myocardial infarction (MI) in comparison with 20 apparently healthy controls.Results: Current data indicate
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