In this study, pebble bed as an absorber and storage material was placed in a south facing, flat plate air-type solar collector at fixed tilt angle of (45°). The effect of this material and differ- ent parameters on collector efficiency has been investigated experimentally and
theoretically. Two operation modes were employed to study the performance of the solar air heater. An inte- grated mode of continuous operation of the system during the period of (11:00 am – 3:00 pm) and non-integrated mode in which the system stored the solar energy through the day then used the stored energy during the period of (3:00 pm – 8:00 pm). The results of parametric study in case of continuous operating showed that the maximum average temperature difference of air between inlet and outlet sections observed on (0.018 kg/s) air mass flow rate were exceeded (17°C) and the maximum outlet temperature that got was exceeded (34°C) for the three months (December, January and February) of experiments. Average efficiency was ranged from 53% to 65%. In the case of storage and then operating, the maximum outlet air temperature was ranged from (27°C) up to (31°C) then
decreased with spend of energy to reach (13°C) to (18°C) and the maximum storage energy was (165.14 W) for the porosity of (0.29) , height of (20 cm) and (0.01 kg/s) mass flow rate. The results also, showed that the solar air collector supplied a solar heating fraction (SHF) with an average of (0.65) for a meeting room (3 * 4 * 7 m) located in Baghdad as a case study.
Orbital varices are vein dilations in the orbit presenting various symptoms. This scoping review synthesizes existing evidence on their epidemiology, clinical features, and treatment efficacy.
Literature was reviewed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed and Scopus were searched until April 31, 2024, for articles on clinically diagnosed ocular varices detailing diagnostic methods, treatments, and outcomes. Exclusions were reviews, animal studies, and incomplete case reports. Data on study characteristics, diagnosis, management, and o
The purchase of a home and access to housing is one of the most important requirements for the life of the individual and the stability of living and the development of the prices of houses in general and in Baghdad in particular affected by several factors, including the basic area of the house, the age of the house, the neighborhood in which the housing is available and the basic services, Where the statistical model SSM model was used to model house prices over a period of time from 2000 to 2018 and forecast until 2025 The research is concerned with enhancing the importance of this model and describing it as a standard and important compared to the models used in the analysis of time series after obtaining the
... Show MoreBackground: Lymphomas are group of diseases caused by malignant lymphocytes that accumulate in lymph nodes and caused the characteristics lymphadenopathy. Occasionally, they may spill over into blood or infiltrate organs outside the lymphoid tissue. The major subdivision of lymphomas is into Hodgkin lymphoma and non–Hodgkin lymphoma and this is based on the histologic presence of Reed-Sternberg cells in Hodgkin lymphoma. Salivary immunoglobulin A is the prominent immunoglobulin and is considered to be the main specific defense mechanism in oral cavity. The aim of this study was to determine the level of salivary immunoglobulin A in lymphoma patients before and after chemotherapy treatment. Subjects, materials and methods: The study i
... Show MoreDue to the importance of nanotechnology because of its features and applications in various fields, it has become the focus of attention of the world and researchers. In this study, the concept of nanotechnology and nanomaterials was identified, the most important methods of preparing them, as well as the preparation techniques and the most important devices used in their characterization.
The research problem is to determine the nature of the historical relationship between the profession of social work and volunteer work. Consequently, the research aims to investigate the nature of this relationship from a socio-historical perspective. Three axes have been used to analyze this relationship: the role of voluntary work in the development of the social work as a profession, the efforts made by social work to reach professionism and to distinguish it from voluntary work, and the relationship between social work and voluntary work. The research is qualitative analytical research and adopts the Mixed Methods Research (MMR). It identifies some literature for the analysis and implementation of a scoping process. It represents a
... Show MoreThe experiment was aimed to evaluate a locally manufactured a dual-action device used for measuring feed pellets durability. The device performs dropping process in conventional devices, then sifting process to separate the pellets from the crumbles simultaneously, with a control the motor speed by using the pulse width modulation (PWM) Technique. The device performance was compared with the durability measuring device of a moving drop box. Rotational speed, diameter of the die holes of the machine was used in this study. The results showed that increasing the rotational speed of the die from 280 to 300 and to 320 rpm, increasing the die holes diameter from 3 to 4 and to 5 mm, led to