The performance of a condenser in a domestic refrigerator system without wires and a condenser with a novel design consisted of number of loops as elliptical shape is investigated experimentally in this work. The experiment was conducted with a refrigerator designed to work with HFC134a, under no load and with loads of (1.5,3 and 12 liters of water). In particular, the effects of shape change of the condenser were very important in heat transfer enhancement and reduce of the frictional loss as a result of reducing the pressure drop in the condenser. The results shown that compressor work decreases with elliptical condenser about (8.6% to 11.3%), and then the power consumption decreases also. The performance of household refrigerator with an elliptical condenser without fins was better than that of the conventional condenser without fins. Therefore, the elliptical condenser can be used instead of the conventional air cooled condenser in a domestic refrigeration system.
The two-frequency shell model approach is used to calculate the
ground state matter density distribution and the corresponding root
mean square radii of the two-proton17Ne halo nucleus with the
assumption that the model space of 15O core nucleus differ from the
model space of extra two loosely bound valence protons. Two
different size parameters bcore and bhalo of the single particle wave
functions of the harmonic oscillator potential are used. The
calculations are carried out for different configurations of the outer
halo protons in 17Ne nucleus and the structure of this halo nucleus
shows that the dominant configuration when the two halo protons in
the 1d5/2 orbi
This paper is concerned with pre-test single and double stage shrunken estimators for the mean (?) of normal distribution when a prior estimate (?0) of the actule value (?) is available, using specifying shrinkage weight factors ?(?) as well as pre-test region (R). Expressions for the Bias [B(?)], mean squared error [MSE(?)], Efficiency [EFF(?)] and Expected sample size [E(n/?)] of proposed estimators are derived. Numerical results and conclusions are drawn about selection different constants included in these expressions. Comparisons between suggested estimators, with respect to classical estimators in the sense of Bias and Relative Efficiency, are given. Furthermore, comparisons with the earlier existing works are drawn.
We are used Bayes estimators for unknown scale parameter when shape Parameter is known of Erlang distribution. Assuming different informative priors for unknown scale parameter. We derived The posterior density with posterior mean and posterior variance using different informative priors for unknown scale parameter which are the inverse exponential distribution, the inverse chi-square distribution, the inverse Gamma distribution, and the standard Levy distribution as prior. And we derived Bayes estimators based on the general entropy loss function (GELF) is used the Simulation method to obtain the results. we generated different cases for the parameters of the Erlang model, for different sample sizes. The estimates have been comp
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The effluent quality improvement being discharged from wastewater treatment plants is essential to maintain an environment and healthy water resources. This study was carried out to evaluate the possibility of intermittent slow sand filtration as a promising tertiary treatment method for the sequencing batch reactor (SBR) effluent. Laboratory scale slow sand filter (SSF) of 1.5 UC and 0.1 m/h filtration rate, was used to study the process performance. It was found that SSF IS very efficient in oxidizing organic matter with COD removal efficiency up to 95%, also it is capable of removing considerable amounts of phosphate with 76% and turbidity with 87% removal efficiencies. Slow sand filter efficiently reduced the mass of suspended
... Show MoreAccording to the circumstances experienced by our country which led to Occurrence of many crises that are the most important crisis is gaining fuel therefore , the theory of queue ( waiting line ) had been used to solve this crisis and as the relevance of this issue indirect and essential role in daily life .
This research aims to conduct a study of the distribution of gasoline station in (both sides AL – kharkh and AL Rusafa, for the purpose of reducing wasting time and services time through the criteria of the theory of queues and work to improve the efficiency of these stations by the other hand. we are working to reduce the cost of station and increase profits by reducing the active serv
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This research prepared polymer blend contains from epoxy resin (Ep) and polyurethane
)Pu) as a matrix material of percentage (90 %) from epoxy and ) 10 (% polyurethane and
reinforced by PVC fibers and aluminum fibers two dimension knitted mat with fractional
volume(15 %), and study impact strength before and after reinforcing at temperatures of
(20,40,60(
o
CØŒand the results have shown that the reinforcing matrix materials by fibers
increased impact strength values that rise from(3.387kJ/m2) to (151.62kJ/m2) of composite
material (Ep+Pu+PVC(and thus ) Ep+Pu+PVC+Al.F) at last (Ep+Pu+Al.F (. following
composite material so that temperatures increase led to rise impact strength values except the
polymer
Abstract
All central air conditioning systems contain piping system with various components, sizes, material, and layouts. If such systems in operating mode, the flow in piping system and its component such as valves can produce severe vibration due to some flow phenomenon’s. In this research, experimental measurements and numerical simulation are used to study the flow-induced vibration in valves. Computational fluid dynamics (CFD) concepts are included with one-way and two-way fluid-structure interaction concepts by using finite element software Package (ANSYS 14.57). Detection analysis is performed on flow characteristics under operation conditions and relations with structural vibration. Most of
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Purpose: To determine the impact of service encounter in stimulating voluntary customer behaviors.
- Approach / methodology: It was selected a sample of customers Bank Iraqi Trade (TBI) was (105) individual, using a questionnaire designed in the light of previous studies, was drafted scale and tested in the light of a group of statistical methods developed (reliability coefficient, reliability coefficient composite, convergence). Then test hypotheses through structural equation modeling.
- Results: The behaviors and characteristics of the service provider in effect urged bank customers to perform voluntary extra, as the service environment service encounter
The formula of Ijarah and Ijarah ending with ownership is one of the investment formulas in Islamic banks, so this research has shed light on it in order to benefit from the experiences of the research sample banks, This research aims to find a reliable way for Iraqi Islamic banks, namely (leasing and leasing ending with ownership) in order to invest their money without usurious interests, The problem of the research emerges through the lack of awareness of the Iraqi Islamic banks to work with different Islamic financing formulas and their inability to invest their money through the adoption of their administrations for different formulas, including the leasing, and this is reflected in the decrease and fluctuation of its profits, Theref
... Show MoreIn this paper, the relationship between urban growth, land use, site availability, and impacts on the general appearance of the city generated by functional characteristics of port cities were analyzed. Various data were used to identify patterns of land use change and city growth and expansion. The research aims to analyze the impact of the port on the growth of the city, study the urban growth of the city of Umm Qasr and predicting the growth trends, and to identify the most influential factors in this growth. The study dealt with the concepts of urban growth and the factors that characterize the growth of port cities and the current situation of the city. The practical part included the mechanisms used by the researcher to analyze the
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