To create a highly efficient photovoltaic-thermal (PV-T) system and maximise the energy and exergy efficiency, this study aims to propose an innovative configuration of a PV-T system comprising wavy tubes with twisted-tape inserts. Following the validation of a numerical model, a parametric study has been conducted to assess the geometrical effects of twisted tape and wavy tubes, as well as the coolant fluid type and velocity, on the overall performance of a PV-T system, located in Shiraz, Iran. It is found that employing twisted tape improves the energy and exergy efficiency by approx. 6.3%. The best configuration yields 12.4% and 16.8% increase in energy and exergy efficiency compared to conventional PV systems. This is achieved at 15% volumetric concentration of microencapsulated phase change material slurry. The monthly variation of global horizontal irradiance in Shiraz highly affected the energy and exergy efficiency of PV-T, with July and October exhibiting the most efficient months, corresponding to 90% and 11.3%, respectively.
The research aims to shed light on the nature of the tax gap in the income tax by the method of direct deduction and its reflection on the financial objective of the tax, and to determine the reasons for this gap in the deduction between the tax due in accordance with the laws and instructions in force and the tax actually paid. The tax gap is a real problem that cannot be ignored for what it represents loss of financial revenues due to the state.
The research problem is represented in the existence of a gap between the tax due according to direct deduction instructions and the tax actually paid according to the financial statements, and to achieve the objectives of the research and test the hypotheses, t
... Show MoreThe aim of the research is to evaluate the response of the researched leaders towards practicing the concept of the lens, which is its dimensions with (stakeholders, resource mobilization, knowledge development, culture management) and the nature of its relationship to tax pioneer performance represented in its dimensions (strategic direction, leadership indicators, growth, renewal and modernization, efficiency, Effectiveness) The questionnaire was approved as a main tool in collecting data and information from the sample members in the General Authority of Taxes, which number (91) Who are on (M. General Manager, Division Director, Deputy Director, Senior Division Director, Deputy Director, Second Division, Division Officer, M. D
... Show MoreThe purpose of the current work was to evaluate the effect of Radiation of Gamma on the superconducting characteristics of the compound PbBr2Ca1.9Sb0.1Cu3O8+δ utilizing a 137Cs source at doses of 10, 15, and 20MRad. Solid state reaction technology was used to prepare the samples. Before and after irradiation, X-ray diffraction (XRD) and superconductor properties were examined. Results indicated that the tetragonal structure of our chemical corresponds to the Pb-1223 phase with an increase in the ratio c/a as a result of gamma irradiation. (Tc (onset) ) and on set temperature Tc (offset)) were also dropping from 113 to the 85.6 K and 129.5 to 97 K, respectively, for a transition temperatu
The follower to study the markets in the Islamic Mashreq (Iraq, Persia and the country of Ma
Behind the river for the period from the reign of the Prophet Muhammad until the end of the Islamic era) to find that there
A remarkable development in the pattern, shape, planning and privatization of markets
Islamic cities and places are the main conditions for their existence, which is the mosque of the mosque
And markets, and these markets have evolved from being a space in which there are no building and no ceilings to shade them in
The places of sale and purchase to specialized markets classified according to the materials and goods produced in them
This would facilitate the task of supervising it by the market factor and
This research seeks to study the role of proactive leadership as an essential element that helps all federations that lead the wheel of sports, including the Iraqi Handball Federation, so that it builds a correct environment that helps manage the organizational errors that the Handball Federation may fall into, and this in turn helps in early detection of errors and obstacles that may occur. It is likely that the Federation will fall into the process of managing and organizing the Iraqi Handball League, in addition to increasing the clubs’ ability to assist the Iraqi Handball Federation by being proactive so as not to make mistakes. The research community included the administrative bodies of the clubs participating in the Iraqi E
... Show MoreUsing sodium4-((4,5-diphenyl-imidazol-2-yl)diazenyl)-3-hydroxynaphthalene-1-sulfonate (SDPIHN) as a chromogenic reagent in presence of non-ionic surfactant (Triton x-100) to estimate the chromium(III) ion if the wavelength of this reagent 463 nm to form a dark greenish-brown complex in wavelength 586 nm at pH=10,the complex was stable for longer than 24 hours. Beer's low, molar absorptivity 0.244×104L.mol-1.cm-1, and Sandal's sensitivity 0.021 µg/cm2 are all observed in the concentration range 1-11 µg/mL. The limits of detection (LOD) and limit of quantification (LOQ), respectively, were 0.117 µg/mL and 0.385µg/mL. (mole ratio technique, job's method) were employed to
... Show MoreLas diferencias entre el pretérito perfecto simple y el imperfecto son uno de los temas más complejos de la lengua española, no sólo para el estudiante, sino para el profesor, puesto que sistematizar los casos y hacerlos fácilmente comprensibles al alumno es tarea difícil. Los profesores de lengua, cuyas investigaciones han dado lugar a una serie de teorías y de corrientes metodológicas y didácticas que permiten enfocar la enseñanza de una lengua extranjera de manera muy distinta a como se hacía tradicionalmente. Vamos a repasar muy brevemente cuáles son estas teorías.
En primer lugar es necesario señalar en qué consiste el aprendizaje de una segunda lengua:
"El aprendizaje de una segunda lengua (L2) es el
... Show MoreEl estudio se clasifica dentro los estudios teóricos sobre literatura que se ocupa del estudio de los métodos de la crítica literaria: El Estructralismo literario francés y el Formalismo ruso del siglo XX que se utilizan en la interpretación literaría. Las dos corrientes literarias estudian la literatura como ciencia que busca aplicar un método científico al estudio de la literatura. Dicho estudio trata de exponer las teorías críticas que surgen en el debate de la interpretación de los textos literarios como el de Susan Sontag, Ricoeur Paul y Mijail Bajitin, etc. Además se incluye algunos ejemplos implican el análisis estructuralista y formalista como Kafka y la tragedia Judía. y Sur Racine.
ABSTRACT:
... Show MoreThis study aims to examine the sources of organizational power prevailing among the academic leaders at the University of Tabuk from the faculty members’ viewpoint. The purposes behind such an aim are: to reveal the level of administrative and technical institutional creativity, the nature of the relationship between the reality of organizational power and the level of institutional creativity, and to disclose statistically the significant differences between the averages of faculty members’ responses attributed to the demographic variables (gender, years of experience, academic degree). The study used the descriptive approach, both survey and correlational. A questionnaire was used to collect data from a simple random sample o
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