The enhancement of the thermal and thermo-hydraulic performance of a semi-circular solar air collector (SCSAC) is numerically investigated using porous semi-circular obstacles made of metal foam with and without longitudinal porous Y-shaped fins. Two 10 and 40 PPI porous material samples are examined. Three-dimensional models are built to simulate the performance of SCSAC: model (I) with clear air passage; model (II) with only metal foam obstacles, and model (III) with metal foam obstacles as well as porous Y-fins. COMSOL Multiphysics software version 6.2 based on finite element methodology is employed. A conjugate heat transfer with a (k-ε) turbulence model is selected to simulate both heat transfer and fluid flow across the entire computational domain. However, only the local thermal non-equilibrium (LTNE) model of heat transfer is applied in the porous regions. The findings demonstrated that adding metal foam as the novel proposed configuration particularity of model (III) may enhance the thermal efficiency by about 30%, and the outlet air temperature may rise to 7% compared to other models. Also, the performance evaluation factor of this model is greater than one in all cases. Additionally, the thermal enhancement is accomplished by occupying only 5% of the air passage volume, thereby including an associated pressure drop of minimal magnitude.
This work concerns the synthesis of two types of composites based on antimony oxide named (Sb2O3):(WO3, In2O3). Thin films were fabricated using pulsed laser deposition. The compositional analysis was explored using Fourier transform infrared spectrum (FTIR), which confirms the existence of antimony, tungsten, and indium oxides in the prepared samples. The hall effect measurement showed that antimony oxide nanostructure thin films are p-type and gradually converted to n-type by the addition of tungsten oxide, while they are converted almost instantly to n-type by the addition of indium oxide. Different heterojunction solar cells were prepared from (Sb2O3:WO
... Show MoreFour new binuclear Schiff base metal complexes [(MCl2)2L] {M = Fe 1, Co 2, Cu 3, Sn 4, L = N,N’-1,4-Phenylenebis (methanylylidene) bis (ethane-1,2-diamine)} have been synthesized using direct reaction between proligand (L) and the corresponding metal chloride (FeCl2, CoCl2, CuCl2 and SnCl2). The structures of the complexes have been conclusively determined by a set of spectroscopic techniques (FT-IR, 1H-NMR, and mass spectra). Finally, the biological properties of the complexes have been investigated with a comparative approach against different species of bacteria (E. coli G-, Pseudomonas G-, Bacillus G+,
... Show MoreNitrogen-comprising heterocyclic compounds and their derivatives have empirically been invaluable as therapeutic agents. Fundamentally, 4-chloro-6-nitro-2-amino-1,3-benzothiazole 1 was synthesized via bromination of 2-chloro-4-nitro aniline with ammonium thiocyanate. This new heterocyclic haloorganoamino-1,3-benzothiazole derivative, was a starting material, which condensed and tethered with three different aromatic aldehyde pendant arm in presence of ethanol and glacial acetic acid isolating an interesting sequence of tridentate Schiff bases 2-4. These compounds were used for complexation reactions in 1:1 (metal: ligand) stoichiometry to obtain heteroleptic Al(III), Ni (II) and K(I) benzothiazole chelat
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ABSTRACT
The researcher seeks to shed light on the relationship analysis and the impact between organizational values in all its dimensions (Administration Management, Mission, relationship management, environmental management) and strategic performance (financial perspective, customer perspective, the perspective of internal processes, learning and development) in the presidency of Two Universities of Baghdad & Al-Nahrain, it has been formulating three hypotheses for this purpose.
The main research problem has been the following question: Is there a relationship and the impact of bet
... Show MoreMetal foam has recently been used in many engineering applications, such as solar collectors, heat exchangers, and cooling of electronic devices, which calls for studying different cases of using metal foam in these applications. The current study conducts a numerical analysis of heat transfer and fluid flow characteristics for air in a rectangular channel filled with high-porosity copper foam. The study examined the thermal performance for two cases of gradient pore density, which are arranged as (10-20-40) PPI and (40-20-10) PPI. These cases were compared with two other cases for constant pore density, 10 and 40 PPI, and empty cases. The ANSYS FLUENT 20.0 employed the Darcy-Forchheimer extended Brickman model in the two-dimensiona
... Show MoreThis research seeks to identify the dimensions of the development of staff performance (training ', incentives, management skills) and its impact on the settlement of compensatory claims adopted in the current research in the Iraqi insurance company،This research aims to highlight the role of developing insurance company’s workers’ performance in settling insurance compensation, and to check this process, the research was applied in the general Iraqi insurance company as it considered as the research community, and a sample was taken from this community that represented by company’s insurance department workers or by collecting actual data that is related to the research’s sample, in addition to the financial compensation data.<
... Show MoreThis research aims at studying each of the cold and hot thermal wavelengths affecting
Iraq for a minimum climatic course of 11 years beginning from 1992 till 2002. Three stations
were selected including the parts of Iraq surface: Mosul, Baghdad and Basrah.
The wave days were also connected with the related climatic elements represented by
the wind direction and speeds and the relative humidity. It was shown that Iraq is affected by
the rates of hot thermal wave lengths greatly compared to the rates of cold wavelengths. The
results suggested that the highest rate of hot and cold wavelengths recorded over Basra station
was (3.5) days for the cold and (5) days for the hot. While the lowest rates was at Mosul
station