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Exergy Analysis of a Domestic Refrigerator
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An energy and exergy thermodynamic analysis using EES program was done for a domestic refrigerator working with R-134a using vapor compression refrigeration cycle. The analysis deals with the system component, i.e. compressor, condenser, evaporator and the expansion device. The analysis depends on the entropy generation minimization approach to improve the refrigerator performance by exploring the optimum design points. These design points were derived from three different theories governing the entropy generation minimization using exergy analyzing method. These theories were first applied to find the optimum balance between the hot inner condenser area and the cold inner evaporator area of the refrigerator and between its hot and cold thermal conductances. Nine types of condensers were used according to its internal surface area and thermal conductance, in order to reach the minimum entropy generation in the refrigerator. The results showed that the compressor has the lowest exergy efficiency of 25%. The expansion device was the second component after the compressor with exergy efficiency of 92%, followed by the condenser with an efficiency of 93%. The evaporator was found to have an exergy efficiency of 98 %. The experimental tests were repeated for the nine condensers sizes with three different ambient temperatures 25℃, 30℃ and 35℃.  The exergy analysis showed that the design of the refrigerator mainly depends on thermal conductance calculations rather than the surface inner area estimation.

 

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Publication Date
Sun Jun 04 2017
Journal Name
Baghdad Science Journal
Effect of Ferocene Concentration on the Percent Conversion and Molecular Weight of Poly(Methyl Methacrylate) Homopolymers
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This research is addressing the effect of different ferrocene concentration (0.00, 2.15x10-3, 4.30x10-3, 8.60x10-3, and 12.9x10-3) on the bulk free radical polymerization of methyl methacrylate monomer in benzene using benzoyl peroxide as initiator. The polymerization was conducted at 60º C under free oxygen atmosphere. The resulting polymers were characterized by FTIR. The results were compared with the presence and absence of ferrocene at 10% conversion. The %conversion was 3.04% with no ferrocene present in the polymerization medium and its increase to 9.06 with a first lowest ferrocene concentration added, i.e. 2.15 x10-3mol/l. This was positively reflected on the poly(methyl methacrylate) molecular weight measured by viscosity techniq

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Publication Date
Fri Dec 01 2017
Journal Name
Ibn Al-haitham Jour. For Pure & Appl. Sci.
Synthesis, Characterization and Study of Mesomorphic Behavior of New Bent and Liner Core Compounds Containing Heterocyclic
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We described herein the synthesized and characterized of new bent and liner core compounds containing thiazolidin-4-one ring[XI-XIII] and [XIV-XVI] respectively. These compounds synthesized by sequence reactions starting from reaction resorcinol or hydroquinone with chloracetyl chloride to yield compounds [I] and [II] ,then the later compounds reactant with 4-hydroxybenzylaldehyde to product dialdehyde compounds [III] and [IV] .The Schiff bases compounds[V-VII] and [VIII-X] synthesized from reaction the compound [III] or [IV] with different aromatic amines, while the bent and liner core mesogens containing thiazolidin-4-one ring [XI-XIII] and [XIV-XVI] synthesized from reaction Schiff bases compounds[V-VII] or [VIII-X] with thioglycolic aci

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Publication Date
Thu Jul 01 1999
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
Grain size and sorting as indicators of depositional environment of ghar formation (late lower Miocene), Iraq
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Char formation is subdivided into three lithological types according to the percentage of detrital quartz and calcite (micrite and sparite), through the petrographic study of 13 thin sections collected from a section at Wadi Al-Ratgha (west of Al-Qaim, Iraq Western Desert). The three rock units are: Limy sandstone, limestone and sandy limestone. Depending on the mean gain size of detrital quartz and degree of sorting and the type of matrix, Ghar Formation can be classified in to three types, i. e. off-shore sediments with low energy environment, near shore sediments with high energy environment and mixed sediments with transitional energy environment. This is due to local transgression and regression of sea level at late lower Miocene du

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Publication Date
Mon Jul 25 2022
Journal Name
International Journal Of Health Sciences
Sequencing of ca-int-l gene of Candida Spp. In infected urinary tract among Iraqi women
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The most common nosocomial fungal infection in hospitals is urinary tract candidiasis. Candida albicans is the most prevalent cause of nosocomial fungal urinary tract infections, however Candida species distribution is changing rapidly. At the same time, the rise in urinary tract candidiasis has resulted in the emergence of antifungal-resistant Candida species. This study aimed to diagnose Candida Spp. In women with UTI and reveal the nucleotides sequences of CA-INT-L Gene to look for mutation within the gene. This study included 100 women patients suffering from urinary tract infections and vaginal swabs samples from those individuals were taken to identify the presence of Candida. They were between the ages of 22 and 67. Candida i

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Publication Date
Fri Oct 28 2022
Journal Name
Political Sciences Journal
The dialectic of the relationship between democracy and freedom in the political thought of karl popper
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Recent studies agree that the democratic system in a country can only be established in an atmosphere of political and religious freedom. However, the term democracy and the term freedom have become controversial because their concepts remain multiple and different. Karl Popper is one of the most prominent philosophers in modern Western political thought, and one of the defenders of democracy as opposite to dictatorship. It has defined its function by its ability to restrain the ruling elite and to enforce it to prevent their tendency to tyranny. This can be achieved only in the context of the close relationship between democracy and freedom, so, if there is democracy in the absence of absolute freedom, democracy is a gateway to expandin

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Publication Date
Wed Jun 09 2021
Journal Name
International Journal Of Pavement Research And Technology
Influence of Mellowing Periods on Short- and Long-Term Performance of Lime-Treated Clay Subgrade Soils
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Publication Date
Sun Oct 29 2023
Journal Name
Iraqi Journal Of Agricultural Sciences
ROLE OF ORGANIC FERTILIZER AND BORON FOLIAR APPLICATION ON GROWTH AND PRODUCTIVITY OF POTATO FOR PROCESSING
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This research was carried out at University of Baghdad - College of Agricultural Engineering Sciences during the fall season of 2020 and spring season of 2021 in order to evaluate the effect of organic fertilizer and the foliar application of boron on the growth and yield of industrial potatoes (Solanum tuberosum L.). Using factorial experiment (5*4) within Randomized Complete Block Design  with three replicates, the organic fertilizer (palm fronds peat) was applied at four levels (0, 12, 24, and 36 ton ha-1) in addition to the treatment of the recommended of chemical fertilizer. The foliar application of Boron was applied at four concentrations which were 0, 100, 150 and 200 mg (H3Bo3). L-1. The results Revealed a significant incr

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Publication Date
Tue Jun 01 2021
Journal Name
International Journal Of Statistical
Evaluating the performance of introduced varieties of maize (Zea Mays L.) and estimating some genetic parameters
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Publication Date
Sat Jan 01 2022
Journal Name
The Journal Of Law Research
Ensuring the right to private property within the framework of the imposition of the arraat tax
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AHA Al-Hilali, AAH Hamid, The Journal of Law Research, 2022

Publication Date
Fri Sep 27 2019
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of ageing on selected salivary chemical compositions and dental caries experience among group of adults
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Background: Ageing is a continuous accumulative ordinary physiological phenomena occurs upon all organs and body structures including saliva by its constituents which can influence the caries process, for that this study was conducted to determine the impact of ageing on selected chemical composition of saliva and their effects on dental caries experience characteristics at different age groups among apparently healthy men. Materials and method: A descriptive comparative study was conducted to compare between three study samples (young, middle and old age adults), thirty male in each study insert, aged (20 years, 40 years and 60 years) respectively. They were selected from private health center in Baghdad - Iraq, from the mid of November

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