Inherent fluctuations in the availability of energy from renewables, particularly solar, remain a substantial impediment to their widespread deployment worldwide. Employing phase-change materials (PCMs) as media, saving energy for later consumption, offers a promising solution for overcoming the problem. However, the heat conductivities of most PCMs are limited, which severely limits the energy storage potential of these materials. This study suggests employing circular fins with staggered distribution to achieve improved thermal response rates of PCM in a vertical triple-tube heat exchanger involving two opposite flow streams of the heat-transfer fluid (HTF). Since heat diffusion is not the same at various portions of the PCM unit, different fin configurations, fin dimensions and HTF flow boundary conditions were explored using computational studies of melting in the PCM triple-tube system. Staggered configuration of fin distribution resulted in significant increases in the rates of PCM melting. The results indicate that the melting rate and heat charging rate could be increased by 37.2 and 59.1%, respectively, in the case of staggered distribution. Furthermore, the use of lengthy fins with smaller thickness in the vertical direction of the storage unit resulted in a better positive role of natural convection; thus, faster melting rates were achieved. With fin dimensions of 0.666 mm × 15 mm, the melting rate was found to be increased by 23.6%, when compared to the base case of 2 mm × 5 mm. Finally, it was confirmed that the values of the Reynolds number and inlet temperatures of the HTF had a significant impact on melting time savings when circular fins of staggered distribution were included.
Nicotiana tobaccum L (Solanacea) extracts are used as a mollusciede to the snail Bulinus truncatus the intermediate host of urinary Schistosomiasis. LC50 of the extracts to the snail with 24 hour was 3.27 ml/l? 48 hour was 3.33 ml/l? 72 hour was 2.67 ml/l and 96 hour was 2.28ml/l. This study showed the ability to use the leaf extracts in the control of this type of snail.
been taken at room temperature down to liquid nitrogen temperature (77K). Polar and nonpolar solvents have been used to study the solvent effect on the absorption and fluorescence spectra of solute molecules. Some of the spectroscopic parameters have been determined as functions of solvent polarity and temperature. The results indicate that the band width FWHM increases with increasing the solvent polarity and temperature, while the peak emission cross section decreases with increasing of solvent polarity and decreases with increasing the temperatures. Clear vibrational structure spectra of benzoanthracene molecules have been observed in Nonane and Hexane solvents at 77K.
Asthma is a chronic inflammatory disease of respiratory airways characterized by distinctive history of respiratory symptoms due to variable airflow obstruction which reverses either spontaneously or in response to certain medications. Acetylcholine is a parasympathetic neurotransmitter which plays fundamental roles in the development of persistent asthma. Treatment guidelines recommend using medium doses of inhaled corticosteroids in addition to another controller bronchodilator instead of using high doses inhaled steroid alone for treatment of moderate to severe persistent asthma. The inhaled long acting muscarinic antagonist, tiotropium, was approved recently to control unresponsive asthma to inhaled corticosteroid with or without a long
... Show MoreBackground: Type two diabetic patients have higher risk of cardiovascular and periodontal disease. Furthermore, patients with more severe periodontal disease have higher incidence of cardiovascular disease. This study aimed to assess the association between periodontal health status and the risk of vascular disease in type 2 diabetic patients. Materials and Methods: One hundred type 2 diabetes mellitus patients and fifty apparently healthy males were enrolled in this study. Oral examinations conducted were; plaque Index, calculus index, gingival index, probing pocket depth, and clinical attachment level. For the assessment of vascular risk, arterial stiffness index was used. Results: According to arterial stiffness index, type 2 diabetic p
... Show MoreThe present study introduces description of new species of leafhopper Cicadella latreilla nov. External morphological characters particularly female genitalia were discussed and illustrated, shape of male abdominal apodeme, chaetotaxy of genital style and genital plate of male genitalia, shape of Aedeagus and connective . The external morphological characters were: spotting patterns of vertex, face, pronotum of prothorax, and metothorax, and of lower and upper valves of ovipositors,shape of female seventh abdominasternum.
An evaluation the performance of the irrigation system for the Al-Ishaqi irrigation project for the Eastern Canal was conducted to identify management strategies that can be used to improve the operation and performance of the irrigation system. The study area is located in Salah al-Din G.0overnorate, Iraq. The field work included determining the moisture content of the soil before and after irrigation, measuring the inflow of the field to find the depth of the applied water, field monitoring, and measuring the depth of the root zone for each irrigation process. Field measurements showed that the average efficiency of water application for the two fields (A, and B) are 59.81% and 38.6%, respectively. The results of the efficiency of
... Show Moret. The current study was conducted on the umbilical cord blood of newborns in the Banks Hospital in Baghdad, Diyala, and Khalis in Diyala, where the study included 90 samples of blood, and samples were collected for the period from the 1st of October;2020 to The first of February;2021 AD, where the study included measuring levels of interleukin-6;Adiponectin,glucose and bilirubin in the blood, comparison study between the study variables with the child's weight (greater than 3 kg),(less or equal 3 kg),the mother's age (greater than 25 years, less or equal to 25 years),the sex of the child (male, female).The results of our study showed that there were no significant differences between the variables of the current study between the two sex
... Show MoreStaphylococcus aureus and Pseudomonas aeruginosa are the major globally distributed pathogens, which causes chronic and recalcitrant infections due to their capacity to produce biofilms in large part. Biofilm production represents a survival strategy in these species, allowing them to endure environmental stress by altering their gene expression to match their own survival needs. In this study, we co-cultured different clinical isolates of S. aureus and P. aeruginosa as mono- and mixed-species biofilms in a full-strength Brain Heart Infusion Broth (BHI) and in a 1000-fold diluted Brain Heart Infusion Broth (BHI/1000) using Microtiter plate assay and determination of colony-forming units. Furthermore, the effect of starvation stress on the e
... Show MorePot experiment was carried out at the College of Agriculture – Baghdad University during autumn season, 2007. Thirteen treatments were formulated to evaluate the effectiveness of four applications of Phosphorus (0, 60, 60×2 and 120 Kg P. h-1) and three applications of Zinc (0, 25×2 mg Zn. L-1 and 50 mg Zn. Kg soil-1) along with inoculating seeds of bean with strains mixture 889 and 1865 and non-inoculated treatment, on nodulation, yield and protein content in seeds (N%). The results showed that inoculated plants exceeded on non-inoculated one in all the studied characteristics. While, P and Zn, applications at the rate of 60×2 kg/ha and 25×2 mg/L respectively, significantly, increased, nodulation, yield, protein content in se
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