Preferred Language
Articles
/
joe-733
Experimental Study on Double-Pass Solar Air Heater with and without using Phase Change Material
...Show More Authors

In this paper, an experimental study was conducted to enhance the thermal performance of a double-pass solar air heater (SAH) using phase change material (PCM) for thermal storage at climatic conditions of Baghdad city - Iraq. The double-pass solar air heater integrated with thermal storage system was manufactured and tested to ensure that the air heating reserved after the absence of the sun. The rectangular cavity filled with paraffin wax was used as a latent heat storage and incorporated into the lower channel of solar air heater. Experiments were carried out to evaluate the charging and discharging characteristics of two similar designed solar air collectors with and without using phase change material at a constant air mass flow rate of (0.0375 kg/sec). The parameters that affect the thermal performance of the SAH with and without the PCMs presented by solar radiation, the difference in air temperature, outlet air temperature, instantaneous thermal efficiency, and daily efficiency are evaluated. The experimental results show that when using the PCM, the temperature of the outlet air was enhanced and increased over the ambient temperature by (1.5 - 6.5 C) after sunset for 5 hours period. It was found that the instantaneous thermal efficiency of the heater using thermal storage exceeds 100% after sunset, this is due to a large amount of heat stored in the paraffin wax that has been released during the discharge process. Also, it was found that the daily efficiency of the double pass SAH integrated with and without thermal energy storage unit was (56, 47%) respectively.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jun 01 2008
Journal Name
Baghdad Science Journal
Observations on the age and growth of Varicorhinus damascinus (Val.) in Tigris river at Salahuldin province – Iraq
...Show More Authors

Age and growth of Varicorhinus damascinus (Val.) in Tigris river at Salahuldin province have been investigated. Monthly samples were taken during the period from September 1999 to August 2000, using small-meshed gill nets. The age data showed that there were six age groups and the dominant age groups were (III – IV) for both sexes. The results of the present study revealed that the increment in length of V. damascinus at the sites of study showed a tendency to decrease with the increase in age, after the third year of life in both sexes. The length-weight relationship of males and females were calculated and demonstrated in a straight line logarithmic formula, as follows: Log W = 1.5404 + 2.6885 log L for males r = 0.95 (P > 0.05) Log

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Apr 16 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effect of Photoperiod on Growth and Reproduction of Cyclops varicans G. O. Sars, 1863 (Cyclopioda – Copepoda )
...Show More Authors

 The species Cyclops varicans G.O.Sars (Which was recorded for the first time in Iraq ) was chossen to study the effect of photoperiods on the species reproduction growth . The chossen photoperiods were 0:24 , 12: 12 , and 24 : 0  L.D.  The data showed obvious statistical effect of photoperiods specially  24 : 0   L.D. on the mean of clutch size ,  produced eggs , no. of nauplei  , transformation time of  nauplius I to copepodid I and transformation time of copepodid I to adult stage . The data also showed uneven effects of photoperiods on the number and maturation period of both males and females . Temperature , transparency , PH , and electrical conductivity also have been studied for the ad

... Show More
View Publication Preview PDF
Publication Date
Tue Jun 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The role of strategic management accounting and its impact on the competitive advantage in Jordanian industrial companies
...Show More Authors

This study aimed to recognize and understand the concept of strategic management accounting (SMA) and how it's the effect on the competitive advantage for industrial companies in Jordan. The study's importance arises due to the lack of Arab studies that dealt with this topic, in addition to the important and vital role of strategic management accounting on companies that represent the artery of the decision-making process, and to identify the benefits associated with SMA technology. The necessary data were collected through the literature review and theoretical study of the references that relevant to the study subject, in addition to a questionnaire developed for this purpose, the study used (124) out of (250) questionnaires tha

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jun 01 2023
Journal Name
Iraqi Journal Of Physics
Studying the Effect of Initial Conditions and System Parameters on the Behavior of a Chaotic Duffing System
...Show More Authors

This work presents a five-period chaotic system called the Duffing system, in which the effect of changing the initial conditions and system parameters d, g and w, on the behavior of the chaotic system, is studied. This work provides a complete analysis of system properties such as time series, attractors, and Fast Fourier Transformation Spectrum (FFT). The system shows periodic behavior when the initial conditions xi and yi equal 0.8 and 0, respectively, then the system becomes quasi-chaotic when the initial conditions xi and yi equal 0 and 0, and when the system parameters d, g and w equal 0.02, 8 and 0.09. Finally, the system exhibits hyperchaotic behavior at the first two conditions, 0 and 0, and the bandwidth of the chaotic

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sun Feb 10 2019
Journal Name
Journal Of The College Of Education For Women
The Effect of a Mediator on Scaffolding EFL Student Teachers’ Teaching Competencies, Self- Efficacy and Self–Awareness
...Show More Authors

This study aims to find out the effect of the mediator on scaffolding fourth yearstudent- teachers' teaching competencies and their self-efficacy. The present study combines scaffolding and self-efficacy by using a mediator on scaffolding students affects teaching competencies and selfefficacy and from the results of which the existence of student-teachers’ selfawareness was ensured as an effect of the same independent variable. The model affects their teaching competencies and led them to be aware of the needs of their pupils and themselves. 

View Publication Preview PDF
Publication Date
Fri Nov 24 2023
Journal Name
Iraqi Journal Of Science
Evaluation Cytotoxic Effect of Nostoc sp. and Scenedesmus acuminatus Extracts on Cell Line Hep -2 in vitro
...Show More Authors

In this Study, isolate and identification two types of algae Scenedesmus acuminatus (Lag.) Chodat belonging to Division of green –algae and Nostoc sp. Of the belong to Division of cyanobacteria from fountain pool at the University of Al- Mustansiriya. Use culture medium Chu- 10 for growth of algae on batch culture in the laboratory conditions (25 ˚ c ±2 and light intensity 200 μE/m²/sec the light:dark regime was used 16:8 hrs). Harvested culture after fourteen days of age farm. Use methanol 95% to extract active compound from raw dry biomass, Tested the effectiveness of the efficiency of the cell extract toward the cell line (human larynx cancer) Hep-2 from biotechnology center at the University of Alnahrain university and differen

... Show More
View Publication Preview PDF
Publication Date
Tue Feb 05 2019
Journal Name
Journal Of The College Of Education For Women
Use of chickpea soaking water in dough fermentation and its effect on quality properties of loaf bread
...Show More Authors

This study was carried out to investigate the possibility of chickpea soaked water as a substitute for yeast in dough fermentation and its effects on sensory properties of the laboratory loaf bread. Chickpea was soaked for 24,48 and 72 hours at room temperature and used in proportion with or without yeast in dough fermentation . The results revealed that , as the percentage of soaked chickpea water substitution increased, the volume of the produced loaf bread decreased as compared with the control treatment (only yeast ).Best results were obtained by using soaked chickpea water for 24 hours in proportion of 1:1 soaked chickpea water : yeast regarding the sensory properties ,volume and leavening of the loaf bread.
Keywords: chickpea so

... Show More
View Publication Preview PDF
Publication Date
Thu Jun 30 2022
Journal Name
Iraqi Journal Of Science
Expressions of CD274 (PD-L1) and CD47 rReceptors on the sSurface of bBlast cCells in AML pPatients
...Show More Authors

     Acute myeloid leukemia (AML) is a genetically heterogeneous clonal disease defined by the proliferation and accumulation of immature hematopoietic cells in the bone marrow and blood. This study aimed to evaluate the CD47 and CD274 (PD-L1) expression in Iraqi AML patients and its role in the disease and evasion of malignant cells from immune system. The study was conducted on 85 patients diagnosed with leukemia, 25 of them were excluded as they had taken chemotherapy for less than a week and because the proportion of tumor cells was less than 20%. Virtually, it was conducted on 60 patients with AML and 20 healthy individuals as a control group.  The expression of CD47 and CD274 (PD-L1) was evaluated using flow cytometry in the p

... Show More
View Publication Preview PDF
Scopus (7)
Crossref (5)
Scopus Crossref
Publication Date
Mon May 01 2023
Journal Name
Journal Of Engineering
Optimization of Inventory Inflation Budget Based on Spare-parts and Miscellaneous Costs of a Typical Automobile Industry
...Show More Authors

Brainstorming has been a common approach in many industries where the result is not always accurate, especially when procuring automobile spare parts. This approach was replaced with a scientific and optimized method that is highly reliable, hence the decision to optimize the inventory inflation budget based on spare parts and miscellaneous costs of the typical automobile industry. Some factors required to achieve this goal were investigated. Through this investigation, spare parts (consumables and non-consumables) were found to be mostly used in Innoson Vehicle Manufacturing (IVM), Nigeria but incorporated miscellaneous costs to augment the cost of spare parts. The inflation rate was considered first due to the market's

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Oct 01 2022
Journal Name
The Egyptian Journal Of Hospital Medicine
The Impact of rs767455 and rs1061622 Polymorphisms ‎on ‎Treatment Outcomes in Iraqi Ankylosing Spondylitis ‎Patients Taking ‎Etanercept
...Show More Authors

Background: Ankylosing spondylitis (AS) is inflammation of the sacroiliac joints and spine, associated with clinical symptoms such as pain and stiffness in the vertebral column, after which, in a considerable number of individuals, new bone growth occurs. Objective: The current research study attempted to find out whether the presence of SNPs in TNF receptor [TNFRSF1A (rs767455), TNFRSF1B (rs1061622)] encoding genes could influence patients' outcomes to etanercept in a specimen of Iraqi AS patients. Patients and methods: Sixty patients with established AS receiving only etanercept were selected to be enrolled in this research with a mean age of 40.75 ± 8.67 years, 51 patients of them were males and only 9 patients were females. Patients we

... Show More
Preview PDF
Crossref (1)
Crossref