Renewable energy resources have become a promissory alternative to overcome the problems related to atmospheric pollution and limited sources of fossil fuel energy. The technologies in the field of renewable energy are used also to improve the ventilation and cooling in buildings by using the solar chimney and heat exchanger. This study addresses the design, construction and testing of a cooling system by using the above two techniques. The aim was to study the effects of weather conditions on the efficiency of this system which was installed in Baghdad for April and May 2020. The common weather in these months is hot in Baghdad. The test room of the design which has a size of 1 m3 was situated to face the geographical south. The test room is thermally insulated and connected to a solar chimney which generates a convection current to draw the air out of the room through a heat exchanger. The heat exchanger was submerged in a water tank of 2 m length, 1 m width and 1 m height. It was also covered with a layer of soil mixture with a thickness of 10 cm. The experiment simulates the natural conditions of a shallow water surface, connected to the room from the other side. The study results revealed that the air temperature inside the test room was lower than that of the ambient air outside. Pearson correlation coefficient showed that there was a strong direct relationship between solar radiation, temperature and wind speed from one side and the cooling efficiency from the other side. Also, there was a negative correlation between relative humidity and cooling efficiency.
The performance measures and traditional methods used in management accounting is no longer able to provide convenient to evaluate the performance of economic units in the modern manufacturing environment information، and so this information is more important and feasibility must be Mistohat of all the company's activities and functions، and it is a problem Find the inadequacy of information management accounting that contribute to meet the needs of the upper levels of management to cope with the problems resulting from the increased size and complexity of the business، and lack of management accounting information and methods used in the performance evaluation، which reflected negatively on the value chain activities and then on the
... Show MoreThe present study was conducted to estimate the incidence, clinical findings, cytological and histopathological characteristics of spontaneously occurring skin neoplasms in dogs. A total of 40 grossly suspected cases of cutaneous and subcutaneous tumors were gathered during the period from July 2016 to August 2018 from male and female dogs in Baghdad city. Dogs with skin neoplasia revealed various clinical signs, and their ages were older than 5 years to 15 years. German shepherd 30% followed by Terrier dogs 25% were more influenced than other breeds. Concerning tumor features, the majority of neoplasms had solitary lesion 70%, regular shapes 65% with black color 55%. The tumors frequently occurred on fore-limbs and abdomen, and 80% of them
... Show MoreIn today’s competitive environment, organizational efficiency and sustained growth are crucial for survival. The performance of an organization is intricately connected to strategic planning, prompting firms to gather and leverage competitive information for a competitive advantage. Senior managers, recognizing this, initiate actions accordingly. This study aims to investigate the relationship between foresight, vision, strategic partnerships, motivation, system thinking, and organizational performance. Data, gathered through a self-administered questionnaire from various textile units, were analysed using structural equation modelling (SEM). The findings indicate that sub-constructs of strategic intelligence positively impact organizatio
... Show MoreAbstract In light of the changing conditions that prevail in society, and the intense competition that institutions and countries are forced to face, especially after the opening of markets, and the transformation of the world into what is called a small village, entrepreneurship has emerged as an important tool for dealing with the developments of societies, whether it is related to individual business projects or Economics for national business, leadership was the key to any driving force towards achieving growth. Today, women are no longer captive to a specific orientation, but rather all horizons and fields of work have been opened to them, and they have been able to occupy the most important economic, voluntary, service, and
... Show MoreA theoretical calculation of the reorientation energy for non adiabatic electron transfer at
interface between metal and semiconductor system was carried out. The continuum outer
sphere theory of electron transfer reaction has been extensively used for electron transfer
between metal/semiconductor interface .It is found that in these calculations the reorientation
energy is proportional to the optical and statistical dielectric constant of semiconductor ,
properties of metal ,and the distance between metal and semiconductor .Results of
reorientation energy show that ZnO semiconductor with metal Au possess a good matching as
compared with ZnS and ZnSe . Theoretical calculation showed a good agreement with
ex
The organizational culture is considered as an important topic. In this research, this topic was studied in modern paints Industries Company to assess its role in job performance and to show if there is this relationship between them or no. it is, also, attempted to measure this strength of this relationship if any. The 40 cases research sample was chosen. This sample included the chief executive, his assistants, key managers, and their assistants. The questioner consists of two sets of questions : the first set ( concerning the organizational culture) covers six variables (Physical structures , Symbols
... Show MoreAn experimental investigation has been made to study the influence of using v-corrugated aluminum fin on heat transfer coefficient and heat dissipation in a heat sink. The geometry of fin is changed to investigate their performance. 27 circular perforations with 1 cm diameter were made. The holes designed into two ways, inline arrangement and staggered in the corrugated edges arrangement. The experiments were done in enclosure space under natural convection. Three different voltages supplied to the heat sink to study their effects on the fins performance. All the studied cases are compared with v-corrugated smooth solid fin. Each experiment was repeated two times to reduce the error and the data recorded after reaching t
... Show MoreIn this paper, a theoretical study of the energy spectra and the heat capacity of one electron quantum dot with Gaussian Confinement in an external magnetic field are presented. Using the exact diagonalization technique, the Hamiltonian of the Gaussian Quantum Dot (GQD) including the electron spin is solved. All the elements in the energy matrix are found in closed form. The eigenenergies of the electron were displayed as a function of magnetic field, Gaussian confinement potential depth and quantum dot size. Explanations to the behavior of the quantum dot heat capacity curve, as a function of external applied magnetic field and temperature, are presented.