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.
The added value of internal audit greatly contributes to adding value to the institution, but most departments of economic units in Iraq neglected the role of internal audit and the added value that can be achieved by those institutions, since the term added value of internal audit is a relatively vague term from the premise that what cannot be measured is difficult Determine it, and perhaps descriptive standards for it is the extent of compliance with international auditing standards (IIA).
The research aims to study the procedures and results of auditing to verify that they have given an added value to the audit with a positive impact, develop its aspects and research, identify deficiencies for the audi
... Show MoreThis study examined the phenomenon of unemployment in Iraq and the extent of the contribution of these loans granted by banks to finance small and medium enterprises in reducing their rates. The temporal boundaries of the study included the period between (2012-2018). The spatial boundaries consisted of random sampling of six Iraqi banks) Where the government banks included (Rafidain, Rasheed and industrial), private banks included (the Iraqi Islamic Bank and the Gulf Commercial Bank and the Bank of the Middle East). In order to achieve the objective of the research in the light of the hypotheses drawn up, the research divided into three topics, the first section highlighting the reality of small and medium enterprises in Iraq and the lo
... Show MoreThis research cancellations in life insurance policies and their impact on the solvency of the insurance companies (Applied Research in the Iraqi general insurance company), The study was descriptive approach in identifying and addressing variables which consists of {cancellations in life insurance} independent variable, the financial solvency of insurance companies as the dependent variable, and for the purpose of achieving the objectives of the research were formulated one hypothesis has been tested in the Iraqi insurance company, the researcher used the financial statements in the collection data needed for the study and information . The research found a number of conclusions highlighted that inflation, as well as economic variables
... Show MoreAbstract
The perpetuity of the Quranic discourse required being suitable for all ages.
Accordingly, the method of the Glorious Quran a pre request for the conscious
investigation and realization in order to detect the core of the texts, as the Quranic
discourse is considered a general address for the humanity as a whole. For this
reason, the progress of the concerned studies neceiated that it should cope with the
current development in the age requirements and its cultural changes within ages.
The texts of the Glorious Quran lightened the human reason as being the
Creator’s miracle for it is characterized by certain merits that makes it different from
poetry and prose. It is a unique texture in its rheto
... Show MoreIt highlights the importance of research through its focus on the assessment of tax for settling accounts Mmakhr medicines and annual statement controls and its role in determining the taxable income of the real tax Mmakhr drugs and achieve tax equity through tax settling accounts. The tax authority relies annual controls laid down by the tax settling accounts for Mmakhr medicines despite their inclusion bookkeeping business No. 2 system for the year 1985 average .ually this basis formulated hypothesis (that the adoption of the tax authority on annual controls in the tax settling accounts for Mmakhr medicine does not contribute in determining income taxable real tax for this Almmakr). the resulting search for a number of conclusions and
... Show MoreAbstract: Thorough assessment of the Maxillary,Sinus is very important. Recently 3-dimensional imagewith Cone Beam Computed Tomography (CBCT) is very dependable in Maxillary Sinus diagnosis. The aim of this study is to: shade light on the role of (CBCT) diagnosis of the maxillary sinus anatomical variation and pathological finding among smokers and nonsmokers prior to maxillary sinus lift techniques. Materials and Method: In this study 60 males with age ranged between 20-50 years old, referred for (CBCT) assessment of maxillary sinus in the Specialist Health Center of AL-Sadder city. The scanning were performed using Kodak 9500 (CBCT), the KV was 90, mA10 and scanning time 10 s. Voxel size 0.3mm with( DICOM ) software on a multiplaner re
... Show MoreDuctal carcinoma in situ is the most commonly diagnosed early stage breast cancer. The efficacy of intraductally delivered poly(ethylene glycol)‐doxorubicin (PEG‐DOX) nanocarriers, composed of one or more DOX conjugated to various PEG polymers, was investigated in an orthotopic ductal carcinoma in situ‐like rat model. In vitro cytotoxicity was evaluated against 13762 Mat B III cells using MTT assay. The orthotopic model was developed by inoculating cancer cells into mammary ducts of female Fischer 344 retired breeder rats. The ductal retention and in vivo antitumour efficacy of two of the six nanocarriers (5 kDa PEG‐DOX and 40 kDa PEG‐(DOX)4) were investigated based o
To achieve the goals, the researcher followed the design of equal and independent groups of partial control and post-test . The research has chosen the Institute of Fine Arts in the area Almansour area as deliberate sample where three sections of students have been chosen and the number of students is (69) students. The researcher conducted equivalence in the variables (age, and IQ , and the overall rate for grade III). in diagnostic phase, (21) concepts of alternative image out of (46) concepts have been identified in addition to the goals of formulation of acquisition concepts according to the three processes (definition, discrimination and application). Achievement test has been
... Show MoreAbstract:
The aerial part of Ephedra foliata Family Ephedraceae have long been used in traditional medicine and now Ephedra species have medicinal, ecological, and commercial value. The variety of pharmacological actions of this plant is due to its chemical constituents. Ephedrine and
related alkaloids; are the newly potential medicinal value of Ephedra supplements for weight loss or performance improvement. Other pharmacological actions like antibacterial and antifungal effects of the phenolic acid compounds, the immunosuppressive action of the polysaccharides, and the antitumor action of flavonoids. The genus of this plant wildly distributed t