Preferred Language
Articles
/
coa6U4YBIXToZYALQILB
Theoretical and experimental investigation of a heat pipe heat exchanger for energy recovery of exhaust air
...Show More Authors

Heat pipes and two‐phase thermosyphon systems are passive heat transfer systems that employ a two‐phase cycle of a working fluid within a completely sealed system. Consequently, heat exchangers based on heat pipes have low thermal resistance and high effective thermal conductivity, which can reach up to the order of (105 W/(m K)). In energy recovery systems where the two streams should be unmixed, such as airconditioning systems of biological laboratories and operating rooms in hospitals, heat pipe heat exchangers (HPHEs) are recommended. In this study, an experimental and theoretical study was carried out on the thermal performance of an air‐to‐air HPHE filled with two refrigerants as working fluids, R22 and R407c. The heat pipe heat exchanger used was composed of two rows of copper heat pipes in a staggered manner, with 11 pipes per row. Tests were conducted at different airflow rates of 0.14, 0.18, and 0.22m3/h, evaporator inlet‐air temperatures of 40, 44, and 50°C, filling ratios of 45%, 70%, and 100%, and ratios of heat capacity rate of the evaporator to condenser sections (Ce/Cc) of 1 and 1.5. For HPHE's steady‐state operation, a mathematical model for heat‐transfer performance was set and solved using MATLAB. Results illustrated that the heat transfer rate was in direct proportion with the evaporator inlet‐air temperature and flow rate. The highest HPHE's effectiveness was obtained at a 100% filling ratio and (Ce/Cc) of 1.5. The predicted and experimental values of condenser outletair temperature were in good agreement, with a maximum difference of 3%. HPHE's effectiveness was found to increase with the increase in evaporator inletair temperature and number of transfer units (NTU) and with the decrease in airflow rate, up to 33% and 20% for refrigerants R22 and R407c, respectively. Refrigerant R22 was the superior of the two refrigerants investigated.

Scopus Clarivate Crossref
Publication Date
Mon Oct 02 2023
Journal Name
Journal Of Engineering
Numerical Assessment of Pipe Pile Axial Response under Seismic Excitation
...Show More Authors

In engineering, the ground in seismically active places may be subjected to static and seismic stresses. To avoid bearing capacity collapse, increasing the system's dynamic rigidity, and/or reducing dynamic fluctuations, it may be required to employ deep foundations instead of shallow ones. The axial aptitude and pipe pile distribution of load under static conditions have been well reported, but more study is needed to understand the dynamic axial response. Therefore, this research discusses the outputs of the 3D finite element models on the soil-pile behavior under different acceleration intensities and soil states by using MIDAS GTS NX. The pipe pile was represented as a simple elastic, and a modified Mohr-Coulomb mode

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
Laminar Forced Convection of Dusty Air through Porous Media in a Vertical Annulus
...Show More Authors

An experimental and numerical study has been carried out to investigate the forced convection heat transfer by clean or dusty air in a two dimensional annulus enclosure filled with porous media (glass beads) between two vertical concentric cylinders. The outer cylinder is of (82 mm) outside diameters and the inner cylinder of (27 mm) outside diameter. Under steady state condition; the inner cylinder surface is maintained at a high temperature by applying a uniform heat flux and the outer cylinder surface at an ambient temperature. The investigation covered values of input power of (6.3, 4.884, 4.04 and 3.26 W), Reynolds number values of (300, 700, 1000, 1500, and 2000) and dust ratio values (density number N) of (2, 4, 6 and 8). A comput

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Materials Today: Proceedings
Energy management and storage systems on electric vehicles: A comprehensive review
...Show More Authors

View Publication
Scopus (58)
Crossref (50)
Scopus Clarivate Crossref
Publication Date
Sat Dec 01 2012
Journal Name
Iraqi Journal Of Physics
Theoretical calculation of internal conversion coefficients for multipole transitions in 88Sr nucleus
...Show More Authors

Internal conversion coefficients (ICC) and electron–positron pair conversion coefficients (PCC) for multipole transition of the core nucleus 88Sr have been calculated theoretically. The calculation is based on the relativistic Dirac–Fock (DF) solutions using the so called ‘‘Frozen Orbital’’ approximation, takes into account the effect of atomic vacancies created in the conversion process, covering a transition energies of 1–5000 keV. A large number of points were used to minimize any errors due to mesh-size effects. The internal conversion coefficients display a smooth monotonic dependence on transition energy, multipolarity and atomic shell. Comparing the values of PCC to ICC, it is interesting to note, that the energy dep

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 07 2015
Journal Name
Baghdad Science Journal
Potential Energy Expectation Value for Lithium Excited State (1s2s3s)
...Show More Authors

The purpose of the present work is to calculate the expectation value of potential energy for different spin states (??? ? ???,??? ? ???) and compared it with spin states (??? , ??? ) for lithium excited state (1s2s3s) and Li- like ions (Be+,B+2) using Hartree-Fock wave function by partitioning techanique .The result of inter particle expectation value shows linear behaviour with atomic number and for each atom and ion the shows the trend ??? < ??? < ??? < ???

View Publication Preview PDF
Crossref
Publication Date
Thu Apr 09 2020
Journal Name
Optoelectronics And Advanced Materials – Rapid Communications
Facile synthesis of Cu2FeSnSe4 nanoparticles for solar energy water splitting
...Show More Authors

Well-dispersed Cu2FeSnSe4 (CFTSe) nanoparticles were first synthesized using the hot-injection method. The structure and phase purity of as-synthesized CFTSe nanoparticles were examined by X-ray diffraction (XRD) and Raman spectroscopy. Their morphological properties were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average particle sizes of the nanoparticles were about 7-10 nm. The band gap of the as-synthesized CFTS nanoparticles was determined to be about 1.15 eV by ultraviolet-visible (UV-Vis) spectrophotometry. Photoelectrochemical characteristics of CFTSe nanoparticles were also studied, which indicated their potential application in solar energy water splitting.

View Publication Preview PDF
Publication Date
Sun Jun 01 2025
Journal Name
Chemical Engineering And Processing - Process Intensification
Wastewater treatment through a hybrid electrocoagulation and electro-Fenton process with a porous graphite air-diffusion cathode
...Show More Authors

View Publication
Scopus (3)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Sun Jun 01 2025
Journal Name
Chemical Engineering And Processing - Process Intensification
Wastewater treatment through a hybrid electrocoagulation and electro-Fenton process with a porous graphite air-diffusion cathode
...Show More Authors

View Publication
Scopus (5)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Sun Jun 01 2025
Journal Name
Chemical Engineering And Processing - Process Intensification
Wastewater treatment through a hybrid electrocoagulation and electro-Fenton process with a porous graphite air-diffusion cathode
...Show More Authors

View Publication
Scopus (5)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Tue Jun 05 2018
Journal Name
Journal Of Molecular Structure
Synthesis, characterization, experimental and theoretical structure of novel Dichloro(bis{2-[1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-ylkN3] pyridine-kN})metal(II) compounds, metal ¼ Mn, Co and Ni
...Show More Authors

The syntheses, characterizations and structures of three novel dichloro(bis{2-[1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II), [M(L)2Cl2], complexes (metal = Mn, Co and Ni) are presented. In the solid state the molecules are arranged in infinite hydrogen-bonded 3D supramolecular structures, further stabilized by weak intermolecular π…π interactions. The DFT results for all the different spin states and isomers of dichloro(bis{2-[1-phenyl-1H-1,2,3-triazol-4-yl-κN3]pyridine-κN})metal(II) complexes, [M(L1)2Cl2], support experimental measurements, namely that (i) d5 [Mn(L1)2Cl2] is high spin with S = 5/2; (ii) d7 [Co(L1)2Cl2] has a spin state of S = 3/2, (iii) d8 [Ni(L1)2Cl2] has a spin state of S =

... Show More
Preview PDF