Air-conditioning systems (ACs) are essential in hot and humid climates to ensure acceptable ambient air quality as well as thermal comfort for buildings users. It is essential to improve refrigeration system performance without increasing the effects of global warming potential (GWP) and ozone depletion potential (ODP). The main objective of this study is to evaluate the performance of an air conditioning system that operates with a liquid suction heat exchanger (LSHX) through implementing refrigerants with zero OPD and low GWP (i.e., R134a and R1234yf). Liquid suction heat exchanger (LSHX) was added to an automobile air conditioning system (AACS).When Liquid suction heat exchanger was added to the cycle, primary results indicated that an enhancement in the cycle coefficient performance (COP) by 25.2 %and 17.3% for R134a and R1234yf respectively, and decreasing in mass flow rate of the refrigerants used (m ̇_r). Also increasing in refrigeration effect (RE) by 4.2% and 2.3% for R134a and R1234yf respectively. Presence of LSHX caused increasing in heat rejected by condenser (Qcond.) according to increasing in sub-cooling degree and decreasing in compressor work (Wcomp.), increasing in condenser exergy destruction (X. des. cond.) and thermostatic expansion device (TXV) exergy destruction, but decreasing in compressor and evaporator. Summary of previous experimental and numerical studies is presented as well.
Construction projects need methods and techniques to ensure the level of quality and commensurate with the level required and documented in the project contract. The quality of the project is affected by the quality of the inputs and accompanying procedures in the construction of the project.
Al-Rumaitha residential project found that the quality of the concrete for the ceilings in the research sample (the roof of the third floor of buildings A25 and A26) and (roof of the second floor of buildings A27, A28, A29, A30, A31, A32 and A33) and roof of buildings A15 and A16 A19)) is not the required quality level.
The idea of the research came after the need to improve the performance o
... Show MoreThis study aims at re-transmit the spirit of the national democratic project of Iraq post of the chaos left by the Daesh terrorist group stage(The Islamic State of Iraq and Syria, ISIS) , Which controlled large parts of Iraq, and had an adverse effect on the political scene in Iraq, inspired everyone that there are deficiencies in the political, economic, religious and ethnic structure of the Iraqi people in non-response to democratic thought.The researcher relied on the hypothesis that " the requirements of building a democratic project are based on the need to provide the requirements ranging from two interrelated aspects, like the institutional aspect and the aspect that related to the general and necessary requirements for the establ
... Show MoreThis valve is intended for use in valves for steering movement, using the qualities of the Magneto-rheological (MR) fluid to regulate the fluid, direct contact without the utilization of moving parts like a spool, a connection between electric flux, and fluid power was made, The simulation was done to employ the" finite element method of magnetism (FEMM)" to arrive at the best design. This software is used for magnetic resonance valve finite element analysis. The valve's best performance was obtained by using a closed directional control valve in the normal state normally closed (NC) MR valve, with simulation results revealing the optimum magnetic flux density in the absence of a current and the shedding condition, as well as the optimum
... Show MoreFlexible pavements are considered an essential element of transportation infrastructure. So, evaluations of flexible pavement performance are necessary for the proper management of transportation infrastructure. Pavement condition index (PCI) and international roughness index (IRI) are common indices applied to evaluate pavement surface conditions. However, the pavement condition surveys to calculate PCI are costly and time-consuming as compared to IRI. This article focuses on developing regression models that predict PCI from IRI. Eighty-three flexible pavement sections, with section length equal to 250 m, were selected in Al-Diwaniyah, Iraq, to develop PCI-IRI relationships. In terms of the quantity and severity of eac
... Show MoreEarth’s climate changes rapidly due to the increases in human demands and rapid economic growth. These changes will affect the entire biosphere, mostly in negative ways. Predicting future changes will put us in a better position to minimize their catastrophic effects and to understand how humans can cope with the new changes beforehand. In this research, previous global climate data set observations from 1961-1990 have been used to predict the future climate change scenario for 2010-2039. The data were processed with Idrisi Andes software and the final Köppen-Geiger map was created with ArcGIS software. Based on Köppen climate classification, it was found that areas of Equator, Arid Steppes, and Snow will decrease by 3.9 %, 2.96%, an
... Show MoreIn this research, porous silicon (PS) prepared by anodization etching on surface of single crystalline p-type Si wafer, then Gold nanoparticle (AuNPs) prepared by pulsed laser ablation in liquid. NPs deposited on PS layer by drop casting. The morphology of PS, AuNPs and AuNPs/PS samples were examined by AFM. The crystallization of this sample was characterized by X-ray diffraction (XRD). The electrical properties and sensitivity to CO2 gas were investigated to Al/AuNPs/PS/c-Si/Al, we found that AuNPs plays crucial role to enhance this properties.
This work aimed to investigate the prevalence of pathogenic fungi and evaluate the antifungal activity of Trichoderma orientale FMR12486 crude extract against pathogenic fungi isolated from patients attending the National Center for Thoracic and Respiratory Diseases (having a history of tuberculosis) and consultant of Dermatology of Baghdad hospital, Iraq. A total of 80 clinical specimens were collected: 20 skin scrapings specimens and 60 sputum specimens. The results of direct examination by KOH 10% and culture showed that 11 (55%) cases from 20 skin specimens were positive for fungal infections, while in the sputum specimens, 28 (47%) cases from 60 were positive. Candida albicans represented the most common fungal infection isolat
... Show MoreThis article reveals the first record of the parasitoid wasp, Monodontomerus obscurus Westwood (Hymenoptera, Torymidae) from Iraq. A total of 27 specimens were emerged from mud nests of sphecoid wasp of Sceliphron sp. (Hymenoptera, Sphecidae), that collected from a wall at a residential garden in Dohuk province. A short morphological description is presented.