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
Thu Oct 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Strategic Intelligence In Decision Making Styles An Analytical research in the Construction& Housing ministry
...Show More Authors

            This research aims to explore the impact of strategic  intelligence by his dimensions (Foresight , system thinking, vision, motivation and partnership) on decision making styles which represented by ( rational, intuitive, dependent, Spontaneous and  Avoidant style) for a sample of the administrative leaders in the center of  Reconstruction &Housing Ministry and Some its formations which are companies of (Sa'ad, Al Mansour, al Farouq, Assyria, al-Mu'tasim, al- Rasheed, and Public Authority for Housing).  So to achieve the  research objectives and to test hypotheses, it has been relying

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Aug 01 2023
Journal Name
Iop Conference Series: Earth And Environmental Science
Diagnosis the Pseudoperonospora cubensis Causes Downy Mildew in Cucumbers and its Resistance to Potassium Silicate and Extract Eggplant Wild
...Show More Authors
Abstract<p>A field experiment was carried out to test the efficiency of potassium silicate and wild eggplant <italic>Solanum eleaegnifolium</italic> normal and nano for the management of downy mildew disease on cucumber caused by <italic>Pseudoperonospora cubensis</italic> under greenhouse conditions by reducing the incidence and severity of the disease and its reflection on the efficiency of the control and the area under the disease progress curve AUDPC compared to the fungicide Energy Previcur (Hcl - Propamocarb and Fosetyl-aluminum). The results of phenotypic and molecular diagnosis using polymerase chain reaction (PCR) technology for the two tested isolates showed that t</p> ... Show More
View Publication
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Mon Jan 19 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Validity of computed tomographic in assessment of genial tubercle and anterior mandible as a reference guide to locate osteotomy in genioglossus advancement
...Show More Authors

Background: Genioglossus advancement is a surgical procedure to advance the tongue in some patients with obstructive sleep apnea syndrome.The important step in this procedure is that of accurately capturing the bone segment attached to the genioglossus muscle to avoid complications such as mandibular fracture, devitalization of the inferior incisor roots, and incomplete incorporation of the genioglossus Materials and Method: Computed tomography scans were taken for 53 Iraqi adult patients (28 male and 25 female) range from (18-35) years with skeletal class I classification and intact anterior mandible dentition included in this study using sagittal and axial sections. The measurements were done for genial tubercle and anterior mandibular re

... Show More
View Publication Preview PDF
Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
Emotional deprivation and its relation with the behavioral and nervous problems for adolescents
...Show More Authors

0

View Publication Preview PDF
Publication Date
Mon Apr 01 2024
Journal Name
Journal Of Krishna Institute Of Medical Sciences University
Study of CD31 IHC expression in dysplastic and malignant lesions of the cervix and its correlation to IHC expression of HPV (16E6 + 18E6)
...Show More Authors

View Publication Preview PDF
Publication Date
Fri Jun 01 2018
Journal Name
Journal Of Engineering
Experimental Study on Tribological Characteristics of AA 6061 Alloy Reinforced with Al2O3 and B4C Particles
...Show More Authors

Two different composite materials were prepared by stir casting method of AA 6061 alloy as a matrix reinforced with two addition different ceramic materials Al2O3 and B4C of grain size   20 µm by 2.5, 5, 7.5 and10% in weight. The composite material with aluminum alloy as a matrix possesses a unique mechanical properties such as: high specific strength and hardness, low density, and high resistance to corrosion and friction wear. This composite is widely used in automotive parts space and marine applications.

Pin-on-disc technique was used to calculate the wear rate for each addition of Al2O3 and B4C particles. Rockwell hardness test and

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Nov 01 2019
Journal Name
Civil Engineering Journal
Experimental and Numerical Investigations of Composite Concrete–Steel Plate Shear Walls Subjected to Axial Load
...Show More Authors

This research is presented experimental and numerical investigations of composite concrete-steel plate shear walls under axial loads to predicate the effect of both concrete compressive strength and aspect ratio of the wall on the axial capacity, lateral displacement and axial shortening of the walls. The experimental program includes casting and testing two groups of walls with various aspect ratios. The first group with aspect ratio H/L=1.667 and the second group with aspect ratio H/L=2. Each group consists of three composite concrete -steel plate wall with three targets of cube compressive strength of values 39, 54.75 and 63.3 MPa. The tests result obtained that the increase in concrete compressive strength results in increasing

... Show More
Scopus (11)
Crossref (10)
Scopus Clarivate Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Materials Today: Proceedings
Experimental and theoretical investigations of seepage reduction through zoned earth dam material with special core
...Show More Authors

View Publication
Scopus (15)
Crossref (10)
Scopus Clarivate Crossref
Publication Date
Tue Jan 29 2019
Journal Name
Journal Of The College Of Education For Women
The Environmental Education and her role to protect an Environment
...Show More Authors

Environmental education is considered as process of getting Humans in communication with this environment and all its various resources. such process requires acquiring knowledge about the environment that com help humans understand their correlative relations with the environmental elements on one hand and among the environmental elements themselves on the other . Besides, such a process requires developing human skills that help them participate in developing environmental circumstances. Therefore environmental education is responsible for perspective and cultural development that governs human behavior. Regarding their environment and stimulating tendencies and interests towards the environment , let alone helping humans acquire the c

... Show More
View Publication Preview PDF
Publication Date
Wed Apr 01 2015
Journal Name
Mathematical Methods In The Applied Sciences
An inverse problem of finding the time-dependent diffusion coefficient from an integral condition
...Show More Authors

View Publication
Scopus (33)
Crossref (23)
Scopus Clarivate Crossref