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
Wed Mar 01 2023
Journal Name
Journal Of Engineering
Stiffness Characteristics of Pile Models for Cement Improving Sandy Soil by Low-Pressure Injection Laboratory Setup
...Show More Authors

Soil improvement has developed as a realistic solution for enhancing soil properties so that structures can be constructed to meet project engineering requirements due to the limited availability of construction land in urban centers. The jet grouting method for soil improvement is a novel geotechnical alternative for problematic soils for which conventional foundation designs cannot provide acceptable and lasting solutions. The paper's methodology was based on constructing pile models using a low-pressure injection laboratory setup built and made locally to simulate the operation of field equipment. The setup design was based on previous research that systematically conducted unconfined compression testing (U.C.Ts.). Th

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (2)
Scopus Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Aip Conference Proceedings
Recovery of methyl orange from aqueous solutions by bulk liquid membrane process facilitated with anionic carrier
...Show More Authors

Dyes are extensively water-soluble and toxic chemicals. The disposing of wastewater rich with such chemicals has severely impacted surface water quality (rivers and lakes). In the current study, an anionic dye, methyl orange, were extracted from wastewater fluids using bulk liquid membranes supplemented with an anionic carrier (Aliquat 336 (QCI)). Parameters including solvent type (carbon tetrachloride and chloroform), membrane stirring speed (100-250 rpm), mixing speed of both phases (50-100 rpm), The feed pH (2-12) and implemented temperature (35-60 °C) were thoroughly analyzed to determine the effect of such variables on extraction effectiveness. Furthermore, the effect of methyl orange (10-50 ppm) in the feed stage and NaOH (0

... Show More
View Publication
Scopus (9)
Crossref (1)
Scopus Crossref
Publication Date
Mon Jan 01 2024
Journal Name
2nd International Conference For Engineering Sciences And Information Technology (esit 2022): Esit2022 Conference Proceedings
Numerical solution to inverse coefficient problem for hyperbolic equation under overspecified condition of general integral type
...Show More Authors

View Publication
Scopus (3)
Crossref (5)
Scopus Crossref
Publication Date
Fri Sep 01 2017
Journal Name
Journal Of Bridge Engineering
Novel Demountable Shear Connector for Accelerated Disassembly, Repair, or Replacement of Precast Steel-Concrete Composite Bridges
...Show More Authors

A novel demountable shear connector for precast steel-concrete composite bridges is presented. The connector uses high-strength steel bolts, which are fastened to the top flange of the steel beam with the aid of a special locking nut configuration that prevents bolts from slipping within their holes. Moreover, the connector promotes accelerated construction and overcomes the typical construction tolerance issues of precast structures. Most importantly, the connector allows bridge disassembly. Therefore, it can address different bridge deterioration scenarios with minimum disturbance to traffic flow including the following: (1) precast deck panels can be rapidly uplifted and replaced; (2) connectors can be rapidly removed and replaced; and (

... Show More
View Publication Preview PDF
Scopus (99)
Crossref (83)
Scopus Clarivate Crossref
Publication Date
Thu Nov 02 2023
Journal Name
Journal Of Engineering
Constructing a Sustainable Roller Compacted Concrete Using Waste Demolished Material as Replacement of Cement: A Review
...Show More Authors

Roller Compacted Concrete is a type of concrete that is environmentally friendly and more economical than traditional concrete. Roller Compacted Concrete is typically used for heavy-duty and specialist constructions, such as hydraulic structures and pavements, because of its coarse surface. The main difference between RCC and conventional concrete mixtures is that RCC has a more significant proportion of fine aggregates that allow compaction and tight packing. In recent years, it has been estimated that several million tons of waste demolished material (WDM) produced each year are directed to landfills worldwide without being recycled for disposal. This review aimed to study the literature about creating a Roller-Comp

... Show More
View Publication Preview PDF
Scopus (8)
Crossref (3)
Scopus Crossref
Publication Date
Tue May 12 2026
Journal Name
International Journal Of Environmental Analytical Chemistry
Eco-friendly chelating Ni(II) nano-compounds for colorimetric optical fiber sensing of heavy metal ions
...Show More Authors

A new Ni(II) nanostructured chelating system (DHN) was introduced for selective optical heavy-metal ion sensing in an aqueous medium. The cooperative chelating system comprising 8-hydroxyquinoline (8-HQ) and dimethylglyoxime (DMG) has been developed for the first time in association with fibre optic sensing for selective optical heavy-metal ion sensing in an aqueous medium. The Ni(II) nanocompound fluoresces upon 578 nm excitation, showing a highly sensitive optical response with a linear calibration curve in the range 0–100 ng/mL. The regression equation of the calibration curve is y = 0.0035x + 0.9990, which indicates very good linearity, implying R2 = 0.999 with high sensitivity (calibration slope of 0.0035) and low baseline noise (bla

... Show More
View Publication
Scopus Crossref
Publication Date
Mon Apr 01 2024
Journal Name
South African Journal Of Chemical Engineering
Removal of COD from petroleum refinery wastewater by adsorption using activated carbon derived from avocado plant
...Show More Authors

View Publication
Scopus (21)
Crossref (11)
Scopus Clarivate Crossref
Publication Date
Tue Mar 30 2021
Journal Name
Baghdad Science Journal
Local Dependence for Bivariate Weibull Distributions Created by Archimedean Copula
...Show More Authors

In multivariate survival analysis, estimating the multivariate distribution functions and then measuring the association between survival times are of great interest. Copula functions, such as Archimedean Copulas, are commonly used to estimate the unknown bivariate distributions based on known marginal functions. In this paper the feasibility of using the idea of local dependence to identify the most efficient copula model, which is used to construct a bivariate Weibull distribution for bivariate Survival times, among some Archimedean copulas is explored. Furthermore, to evaluate the efficiency of the proposed procedure, a simulation study is implemented. It is shown that this approach is useful for practical situations and applicable fo

... Show More
View Publication Preview PDF
Scopus Clarivate Crossref
Publication Date
Sun May 17 2015
Journal Name
Journal Of Physical Education
دراسة تحليلية مقارنة، لبعض المتغيرات الكينماتيكية، في أداء مهارة(Nick shot) الأمامية العكسية، بين لاعبي المنتخب العراقي والمصري، للشباب في الإسكواش
...Show More Authors

هدفت الدراسة الى التعرف على مستوى استخدام إدارة المعرفة و تكنولوجيا المعلومات لدى القيادات الإدارية تُعدّ لعبة الإسكواش من الألعاب الفردية، وواحدة من ألعاب المضرب، والتي تمتاز بالسرعة والحركة الدائمة في داخل القاعة، ولعل أهم ما يميز هذه اللعبة المتعة التي يشعر بها اللاعبون الممارسون لها، لأنها تجبر ممارسيها على الحركة المستمرة عن طريق تبادل لعب الكرة، وتتميز بالتحدي المباشر، وتتطلب اليقظة والحرص وال

... Show More
View Publication
Crossref
Publication Date
Mon Jan 13 2020
Journal Name
Day 3 Wed, January 15, 2020
Numerical Simulation of Gas Lift Optimization Using Genetic Algorithm for a Middle East Oil Field: Feasibility Study
...Show More Authors
<p>Gas-lift technique plays an important role in sustaining oil production, especially from a mature field when the reservoirs’ natural energy becomes insufficient. However, optimally allocation of the gas injection rate in a large field through its gas-lift network system towards maximization of oil production rate is a challenging task. The conventional gas-lift optimization problems may become inefficient and incapable of modelling the gas-lift optimization in a large network system with problems associated with multi-objective, multi-constrained, and limited gas injection rate. The key objective of this study is to assess the feasibility of utilizing the Genetic Algorithm (GA) technique to optimize t</p> ... Show More
View Publication
Scopus (15)
Crossref (8)
Scopus Crossref