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.
In this research a local adsorbent was prepared from waste tires using two-step pyrolysis method. In the carbonization process, nitrogen gas flow rate was 0.2L/min at carbonization temperature of 500ºC for 1h. The char products were then preceded to the activation process at 850°C under carbon dioxide (CO2) activation flow rate of 0.6L/min for 3h. The activation method produced local adsorbent material with a surface area and total pore volume as high as 118.59m2 /g and 0.1467cm3/g, respectively. The produced . local adsorbent (activated carbon) was used for adsorption of lead from aqueous solution. The continuous fixed bed column experiments were conducted. The adsorption capacity performance of prepared activated carbons in this work
... Show MoreIraq has seen many changes at the social, economic and political levels. This led to cause many shifts in the structure of its society and imposed great challenges reflected in the behavior and awareness of that society in general and youth in particular.
Those changes made the Iraqi society undergoing the transformation of value and culture aspects formed a political awareness that caused cultural and political diversity within the family and society. A greater openness to the outside world caused by the communication revolution, as the world has witnessed during the past two decades, has helped in making that change. Iraq had its share of media and political openness, which were included after the US occupation in 2003. As a re
... Show MoreThe diversity of cultures is still the title of an Iraqi specificity that gave the society a diversity and this is reflected in the journalistic reality with the changing of the political system generate a new political and ideological life that differs from what is prevailed during the decades. However, its exacerbation of the degree of division is an additional duty for the press as a cultural platform and a knowledge bridge that contributes to the process of dialogue, addressing the differences, establishing a politically homogeneous structure through the state and socially by uniting all components of society and working to raise public awareness of the importance of national belonging to build a modern state. Cultural diversity is a
... Show MoreWhat distinguishes human rights issues is their importance to the international community and their importance to democratic political regimes, because they are the axis of any political regime that seeks to achieve a successful democratic path and a stable state. So, countries that are interested in human rights try to enshrine those rights and freedoms in their constitutions and reinforce their concepts in their laws and legislations. Not to mention its involvement in international conventions and treaties concerned with human rights and freedoms, and this is what the Sultanate of Oman has worked on and confirm in the provisions of its 1996 constitution and its amendments
The results of theoretical and experimental investigations carried out to study the effect of load and relative sliding speed on the abrasive wear behavior in drilling bit teeth surfaces of an insert tungsten carbide bit have been presented. Experimentally, an apparatus for abrasive wear tests conducted on the modified ASTM-G65 was modified and fabricated to facilitate loading and measurement of wear rate for the sand/ steel wheel abrasion test, which involves two cases of contact; first is at dry sand and second is under wet condition. These tests have been carried under varied operating parameters of normal load and sliding speed. A theoretical model based upon the Archard equation has been developed for predicting wear simulation by u
... Show MoreBackground: In recent years, the prevalence of obesity has climbed sharply. Still, only a few safe and effective medications are approved as weight-loss drugs. Objective: This study aims to assess the knowledge and practice of community pharmacists in Iraq regarding the use of Liraglutide and Semaglutide as weight-loss medications. Method: A cross-sectional survey was implemented using a validated questionnaire and a convenient sample of Iraqi community pharmacists from different governorates. The questionnaire was created after conducting a literature review of the most important articles about liraglutide and semaglutide. The questionnaire consists of three sections. The first part was used to collect demographic information. The
... Show More
The phenomenon of celebration of army leaders in the Abbasid era formed a distinct phenomenon at which the poets stood, and among those leaders was the Arab leader Hamid al-Taie, and the poets who stood on him and his sons Abu Tammam and al-Bohtari recorded in their poems the exploits of that leader, and the exploits of his sons through images that represented sadness, courage In this research, the generosity, and the rhetorical and artistic aspects of those images, have been spotted, balancing the poets.
Pseudoephedrine (PSE) or (Sudafed) is one of the sympathomimetic group of drugs (ephedrine, PSE and amphetamines) which effects cardiovascular system, respiratory system, and gastrointestinal tract. However, only little researches had supported its effect on solid abdominal organs. This study aims to investigate the effects of different doses of Sudafed in the liver and kidney of albino mice. The current study included 18 albino mice grouped into 2 groups: control (3 mice), and acute group (15 mice). The acute group was further subdivided into 5 subgroups, each subgroup of 3mice wasgiven a lonely intaperitonial injection of 0.3ml of the following conc. (500mg/kg, 250mg/kg, 125mg/kg, 62.52mg/kg, and 31.24mg/kg) for 24hrs. After the m
... Show MoreAbstract
Theoretical and experimental methodologies were assessed to test curved beam made of layered composite material. The maximum stress and maximum deflection were computed for each layer and the effect of radius of curvature and curve shape on them. Because of the increase of the use of composite materials in aircraft structures and the renewed interest in these types of problems, the presented theoretical assessment was made using three different approaches: curved beam theory and an approximate 2D strength of material equations and finite element method (FEM) analysis by ANSYS 14.5 program for twelve cases of multi-layered cylindrical shell panel differs in fibe
... Show More