Preferred Language
Articles
/
joe-668
The Experimental Assessment of R134a and Its Lower GWP Alternative R1234yf in an Automobile Air Conditioning System
...Show More Authors

Reducing global warming potential (GWP) of refrigerants is needed to the decrease of ozone-depleting of refrigeration systems leakages. Refrigerant R1234yf is now used to substitute R134a inside mobile air conditioning systems. Thermodynamic properties of R1234yf are similar to R134a. Also, it has a very low GWP of 4, compared to 1430 for R134a, making it a proper choice for future automobile refrigerants. The purpose of this research is to represent the main operating and performance differences between R1234yf and R134a. Experimental analysis was carried out on the automotive air conditioning system (AACS) with 3 kW nominal capacity, to test and compare the performance of R134a with R1234yf. Experiments were accomplished for both refrigerants in almost the same working conditions and procedure with a range of ambient temperature varied from 26oC to 50oC. Parameters studied were ambient temperature, type of refrigerant in the system at compressor speed 1450 rpm, and internal thermal loads of passenger room. The performance characteristics of the system, including COP and cooling capacity, were studied by changing different parameters. The results show that COP of R134a is higher than R1234yf by 12.6%, while the refrigeration effect of R134a is higher than R1234yf by 25%. This shows that R1234yf is a suitable and good candidate for drop-in replacement of R134a in AACS.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Nov 09 2020
Journal Name
Heat Transfer
Experimental performance of cooling photovoltaic panels using geothermal energy in an arid climate
...Show More Authors

View Publication
Scopus (4)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Sun Mar 19 2023
Journal Name
Journal Of Educational And Psychological Researches
An Assessment of People with Intellectual Disabilities Practicing of Physical Activities and Its Challenges under Corona Pandemic (Covid-19) from Their Families' Point of View
...Show More Authors

Abstract

This research aims to assess the practice of physical activities by people with intellectual disabilities and its challenges during the Coronavirus (COVID-19) pandemic from their families' point of view. The research sample consisted of (87) individuals from families with intellectual disabilities in the Makkah region. The sample was selected by the simple random method where the researcher used the descriptive analytical approach. A questionnaire of (32) items was used as the research tool to collect data. The findings of the study showed that the assessment level of practicing physical activities by people with intellectual disabilities was low. The public facilities dimension ranked first with a moder

... Show More
View Publication Preview PDF
Publication Date
Fri Oct 26 2018
Journal Name
Journal Of Planner And Development
Alternative Methods for Decreasing Infrastructure Deficiencies in Iraq
...Show More Authors

View Publication Preview PDF
Publication Date
Sun Dec 30 2018
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Estimating of Pore Pressure Gradient in Lower Fars Formation
...Show More Authors

In petroleum industry, the early knowledge of “pore pressure gradient” is the basis in well design and the extraction of these information is more direct when the pore pressure gradient is equal to normal gradient; however, this matter will be more complex if it deviate from that limit which is called “abnormal pore pressure”, if this variable does not put in consideration, then many drilling problems will occur might lead to entire hole loss. To estimate the pore pressure gradient there are several methods, in this study; Eaton method’s is selected to extract the underground pressure program using drilling data (normalized rate of penetration) and logs data (sonic and density log). The results shows that an abnormal high press

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Thu Nov 14 2019
Journal Name
Advances In Intelligent Systems And Computing
The Application of Bus Rapid Transit System in the City of Baquba and Its Impact on Reducing Daily Trips
...Show More Authors

View Publication
Scopus Clarivate Crossref
Publication Date
Tue Sep 04 2007
Journal Name
Nahrainuniversity
MASS TRANSFER OF NAPHTHALENE FROM AN IMMERSED SURFACE TO A SAND-AIR FLUIDIZED BED
...Show More Authors

Fluidization process is widely used by a great assortment of industries worldwide and represents a trillion dollar industry [6]. They are currently used in separation, classification, drying and mixing of particles, chemical reactions and regeneration processes; one of these processes is the mass transfer from an immersed surface to a gas fluidized bed

Preview PDF
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
A study copepoda invertebrates ecology in lower Zab
...Show More Authors

The samples were collected monthly crustaceans Mjmafah foot of two stations in tributary Zab down and two others in the Tigris River for one year with effect from November 2001 until October 2002 recorded during the study period the current 41 units taxonomic and were higher density of Mjmafah foot Guy Tigris River before the mouth of the tributary

View Publication Preview PDF
Publication Date
Sat Jul 12 2025
Journal Name
Al–bahith Al–a'alami
ELEMENTS OF BUILDING CONTENT FOR GOVERNMENT WEBSITES: : (An Experimental Study)
...Show More Authors

The study dealt with measuring the impact of the availability of each of the content elements of the interaction, electronic services, and information on the evaluation of the users of the government website for its effectiveness in terms of the site’s functions and for measuring the site’s ability to present the organization’s tasks to customer groups.

Authority is concerned with measuring the confidence of customers in the content of the site, and in the organization as a whole. Validity is related to measuring the effectiveness of employing the site’s content to achieve the goal of its creation and in communicating with customers. Availability It is for measuring the ease of use of the site. The relevance, which means

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 14 2023
Journal Name
Malaysian Journal Of Mathematical Sciences
The Effect of Alternative Resource and Refuge on the Dynamical Behavior of Food Chain Model
...Show More Authors

This article examines and proposes a dietary chain model with a prey shelter and alternative food sources. It is anticipated that mid-predators' availability is positively correlated with the number of refuges. The solution's existence and exclusivity are examined. It is established that the solution is bounded. It is explored whether all potential equilibrium points exist and are locally stable. The Lyapunov approach is used to investigate the equilibrium points' worldwide stability. Utilizing a Sotomayor theorem application, local bifurcation is studied. Numerical simulation is used to better comprehend the dynamics of the model and define the control set of parameters.

View Publication
Scopus (6)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Tue Sep 06 2016
Journal Name
Al-qadisiyah Journal For Administrative And Economic Sciences
Awareness of the regulatory and administrative leadership and its role in achieving the effectiveness of the internal control system and achieve fair accountability
...Show More Authors

The research aims to achieve a set of the most important objectives of the review of the role of creative administrative leadership in achieving aspects of economic reform in various government institutions and indicate the role of supervisory awareness of administrative leadership in the revitalization of the role of the internal control system to achieve the best use of available resources. This paper deals with three problems is the loss of financial resources of the state as a result of the growing phenomenon of administrative and financial corruption in the majority of government institutions, and the weakness of the role of the internal control system in the province on the resources available and to achieve the best use of these reso

... Show More
Preview PDF