Due to the potential cost saving and minimal temperature stratification, the energy storage based on phase-change materials (PCMs) can be a reliable approach for decoupling energy demand from immediate supply availability. However, due to their high heat resistance, these materials necessitate the introduction of enhancing additives, such as expanded surfaces and fins, to enable their deployment in more widespread thermal and energy storage applications. This study reports on how circular fins with staggered distribution and variable orientations can be employed for addressing the low thermal response rates in a PCM (Paraffin RT-35) triple-tube heat exchanger consisting of two heat-transfer fluids flow in opposites directions through the inner and the outer tubes. Various configurations, dimensions, and orientations of the circular fins at different flow conditions of the heat-transfer fluid were numerically examined and optimized using an experimentally validated computational fluid-dynamic model. The results show that the melting rate, compared with the base case of finless, can be improved by 88% and the heat charging rate by 34%, when the fin orientation is downward–upward along the left side and the right side of the PCM shell. The results also show that there is a benefit if longer fins with smaller thicknesses are adopted in the vertical direction of the storage unit. This benefit helps natural convection to play a greater role, resulting in higher melting rates. Changing the fins’ dimensions from (thickness × length) 2 × 7.071 mm2 to 0.55 × 25.76 mm2 decreases the melting time by 22% and increases the heat charging rate by 9.6%. This study has also confirmed the importance of selecting the suitable values of Reynolds numbers and the inlet temperatures of the heat-transfer fluid for optimizing the melting enhancement potential of circular fins with downward–upward fin orientations.
In The Name of Allah Most Gracious Most Merciful
This is a study dedicated to explaining the conditions of the end of heaven, stage by stage; And to draw the final picture of it, through the facts of the Qur’an, and to make the contextual integration of the verses of the end of heaven, and their arrangement in an intentional arrangement, a path that guides us to knowing the integrated picture of it on the Day of Resurrection, according to scientific interpretation.
The importance and usefulness of the research lies in:
Extracting the order of the stages of the end of heaven, from its first state to its last, which came in separate verses of the Qur’an, each one of which was placed in a surah that was consistent w
... Show MoreDBN Rashid, International Journal of English Linguistics, 2019 - Cited by 2
In this paper, a mathematical model consisting of a prey-predator system incorporating infectious disease in the prey has been proposed and analyzed. It is assumed that the predator preys upon the nonrefugees prey only according to the modified Holling type-II functional response. There is a harvesting process from the predator. The existence and uniqueness of the solution in addition to their bounded are discussed. The stability analysis of the model around all possible equilibrium points is investigated. The persistence conditions of the system are established. Local bifurcation analysis in view of the Sotomayor theorem is carried out. Numerical simulation has been applied to investigate the global dynamics and specify the effect
... Show MoreMusic and singing are always associated with the movement of society and the emergence of cultural and artistic activities other.
The social and political transformations of the 1930s helped to disseminate the study Music and music in the city of Baghdad and across Iraq This is the beginning of a new era of musical art alongside other arts.
While achieving musical arts A new step was advanced by publishing a technical study among the younger generation they were looking for to contribute to the musical field On the other hand, the city of Baghdad during the period of research many musical and musical performances Egyptian teams have provided many artistic activities and events which have had a significant impact on the development
Abstract The aim of this paper is to shed light on the theme of Gender Struggle and Women’s Predicament in Tennessee Williams’ A Street Car Named Desire .The paper tries to show William's dealings with the critical social themes like Men's Brutality and women's predicament. The paper exposes the complete shift of the balance of power between the genders in America after the two world wars. Williams illustrates society’s changing attitudes towards masculinity and denounces the society's attitudes towards women in America at that time. He rebels against the cruelty of the modern age and regrets the disintegration of the values of the south and their being replaced by the disruptive forces of modern life. In the end of the play, brutalit
... Show MoreRecently, women's rape has been a pervasive problem in the Iraqi society. Thus, it has become necessary to consider the role of language and its influence on the common beliefs and opinions about rape in the Iraqi society. Thus, taking into consideration the critical role of language and its impact on the perception of human reality and the social development based on people's beliefs and principles of life has become highly indispensable. Therefore. The aim of this article is to address this problem critically from legislation and social norms in NGOs' reports (2015; 2019) with reference to some provisions from the Iraqi Panel Code (1969; 2010). Therefore, the researchers examine the discursive strategies and ideological viewpoints in t
... Show MoreThe study aims to build a model that revolves around the main question of the role of strategic agility (SA) in enhancing organizational excellence (OE). For the purpose of achieving OE and to determine the extent of interest and knowledge of managers at the Midwest Refineries Company (MRC) on the theoretical and practical implications, and on the performance foundations of these two vital variables with the aim of continuous improvement. A questionnaire was used and distributed to a random sample of 54 managers in this important energy production company. The study followed the descriptive analytical approach to answer the questions raised. The study model and dimensions were built according to reference models, most notably the mo
... Show MoreThis study aims to determine the prevalence of Entamoeba histolytica, Entamoeba dispar and
Entamoeba moshkovskii by three methods of diagnosis (microscopic examination, cultivation and PCR) that
were compared to obtain an accurate diagnosis of Entamoeba spp. during amoebiasis. Total (n=150) stool
samples related to patients were (n = 100) and healthy controls (n= 50). Clinically diagnosed stool samples
(n=100) were collected from patients attending the consultant clinics of different hospitals in Basrah during
the period from January 2018 to January 2019. The results showed that 60% of collected samples were
positive in a direct microscopic examination. All samples were cultivated on different media; the Bra
Monitoring lotic ecosystems is vital for addressing sustainability issues. The Al-Shamiyah River is the primary source of water for various daily activities in the Al-Shamiyah district. This study assessed the pollution levels of the river by measuring the concentration and distribution of heavy metals—specifically chromium, cadmium, manganese, copper, zinc, and lead—in both the river's water and sediments. The concentrations of heavy metals in the water ranged from 0.05 to 1.44µg/ L for copper (Cu), 1.57 to 7.25µg/ L for manganese (Mn), 0 to 1.7µg/ L for cadmium (Cd), 0.02 to 1.33µg/ L for lead (Pb), 0.08 to 2.74µg/ L for zinc (Zn), and 0.44 to 1.84µg/ L for chromium (Cr). In the particulate phase, the concentrations ranged from
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