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.
Objectives: The aim of the study was, to assess the nurse's role regarding cardiovascular drug
administration in Erbil city.
Methodology: A descriptive survey was conducted in Hawler teaching and Rizgari teaching Hospitals. The
number of samples is 50 nurses; the period of the study was started from 15th of November 2008 up to
the end of March 2009. A questionnaire was developed by investigators based on extensive review of
available studies and literatures. Data were collected through application of observational check list
consist of two part, part one was demographic sheet and part two about nurse’s responsibility regarding
medication administration which include (before, during, after drug administration). Data
The path and its nodal purposes
Abstract
This study has come to indicate the doctrinal purposes of faith in this path، It was composed of an introduction and four demands، as follows:
The first requirement: the intentions of distinguishing between the ranks of people according to divine justice، as those who pass by him are different. Some of them are safe by his work، surviving from the fire، and some of them are not peace، he falls into the fire of Hell، and all of them are different in their ranks in a manner consistent with the justice of God Almighty and the works they have given themselves.
The second requirement: the purposes of divine mercy in honoring the Prophet and his nation on the path and embodying their
Background: Even the wide use of dental implants, still there is a proportion of implants are failed due to infection. Much considerable attention has been paid to modify the implant surface. Coating of dental implant with a biocomposite material of suitable properties can improve osseointegration. And this is the main concern of this study. The aim of present study was to evaluate the use of a biocomposite coating of dental implant with (ceramic nano Al2O3 and metalic AgNo3) on the bond strength at bone – implant interface and tissue reaction. Materials and methods: A total number of forty-eight screws, CpTi dental implant used in this study. Half of these screws were coated with a biocomposite material of nano (Al2O3and AgNo3), thi
... Show MoreAmong several separation processes, the air flotation distinguish as remarkably high potential separation process related to its high separation efficiency and throughput, energy-efficient, simple process, cost-effective, applicable to a wide range of oily wastewater and no by-products. The current study aimed to investigate the effect of the type and concentration of surfactant on the stability of oil-water emulsion and efficiency of the separation process. For this purpose, three types of surfactant where used (anionic SDS, mixed nonionic Span 85/Tween 80, and cationic CTAB). The results demonstrated that the Span 85/Tween 80 surfactant has the best stability, and it increases with the surfactant concentration augmentation. The removal ef
... Show MoreThe present experimental work is conducted to examine the influence of adding Alumina (Al2O3) nanoparticles and Titanium oxide (TiO2) nanoparticles each alone to diesel fuel on the characteristic of the emissions. The size of both Alumina and Titanium oxide nanoparticles which have been added to diesel fuel to obtain nano-fuel is about 20 nm and 25 nm respectively. Three doses of (Al2O3) and (TiO2) were prepared (25, 50, and 100) ppm. The nanoparticles mixed with gas oil fuel by mechanical homogenous (manual electrical mixer) and ultrasonic processor. The study reveals that the adding of Aluminum oxide (Al2O3) and Titanium oxide (TiO2) to g
... Show MoreThe research study includes shedding light on the sas dance in Iraq, as it is one of the popular legacies that are rich in the Mesopotamian civilization and because of the different practices it has in the different occasions on which these dances are held. Which is one of the kinetic arts widespread among the classes of Iraqi society. The researcher explained its features and artistic content that characterizes Iraqi music. The (methodological framework) reviewed the justification, importance and purpose of the research, and the limits of the research that included the (National Troupe of Folk Art) as a human limit to discover the artistic methods of the Sas dance and then define the terms of the search. The "theoretical framework" cont
... Show MoreThe culture of theatre performance has a vital role in the process of reading the linguistic and visual signs of the performance. And the process of transforming a theatre performance from its original context into a new hosting cultural context starts from the actual reading of the text. Directors derives their new signs out of his personal culture, depending on the society where they lives and the culture that forms the social conventions, traditions and beliefs. The text is usually written within its own historical and temporal culture. The process of its production usually takes it away from its original culture, when it interprets the codes of the original writer and their visual and linguistic signs and instils new alternative sign
... Show MoreIn the present investigation, bed porosity and solid holdup in viscous three-phase inverse fluidized bed (TPIFB) are determined for aqueous solutions of carboxy methyl cellulose (CMC) system using polyethylene and polypropylene as a particles with low-density and diameter (5 mm) in a (9.2 cm) inner diameter with height (200 cm) of vertical perspex column. The effectiveness of gas velocity Ug , liquid velocity UL, liquid viscosity μL, and particle density ρs on bed porosity BP and solid holdups εg were determined. The bed porosity increases with "increasing gas velocity", "liquid velocity", and "liquid viscosity". Solid holdup decreases with increasing gas, liquid
... Show MoreThe thyroid gland is a vital part of the overall endocrine system, which is regulated some of body function as oxygen use, basal metabolic rate, growth, cellular metabolism and development This study shed light on a number of extracts that have been shown to have beneficial effects on the thyroid and its function, as well as the various factors linked to thyroid dysfunction. The experiment was conducted to determine the effect of a mixture of two extracts of "Fucus vesiculosus (150 mg/ kg) with Coleus forskohlii (1000 mg/ kg) and Rosmarinus officinalis (220 mg/ kg) with Camellia sinensis (1.25 mg/ kg)" on thyroid hormones as well as lipids profile and tested the effectiveness of two drugs one of them stimulates the hormones of the thyroid (
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