Hussain A. Al-Jobouri,Mohamed Bechir Ben Hamida,Nada F. Tawfiq,Fala Hatem Taha
Issue:
Volume 1, Issue 2, August 2015
Pages:
25-29
Received:
10 June 2015
Accepted:
30 June 2015
Published:
1 July 2015
DOI:
10.11648/j.ajme.20150102.11
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Abstract: Nuclear track detector type CR-39 irradiated by two UV-irradiation methods at wavelength 254nm . First method was PEN-ray-lamp UV-irradiation with the distance 4cm between UV source to CR-39 detector and the range of irradiation time - TD were 10,100 and 1000 s . Second method was FLX-20 transiluminator 15W energy amount with the distance 10 cm between UV source to CR-39 detector and therange of irradiation dose - DT were 2 , 6 , 9 and 10J/cm2. The absorbance-A was determine from UV-visible spectroscopy at the measuring range from 300 – 500 nm for each method .The absorbance differences [ΔA]350 and [ΔA]550 for irradiated and un-irradiated CR-39 detector were measured between absorbance value at wavelength 350nm and 550nm respectively . In this study determined the linear relationship between the increasing of TD(s) and DT(J/cm2) with increasing of [ΔA]350 and [ΔA]550 .This work obtained that FLX-20transiluminator ( second method) was used as a calibration route to PEN-ray-lamp ( first method) after measuring the absorbance deference [ΔA]350 and [ΔA] 550 for CR-39 detector.Abstract: Nuclear track detector type CR-39 irradiated by two UV-irradiation methods at wavelength 254nm . First method was PEN-ray-lamp UV-irradiation with the distance 4cm between UV source to CR-39 detector and the range of irradiation time - TD were 10,100 and 1000 s . Second method was FLX-20 transiluminator 15W energy amount with the distance 10 cm bet...Show More
Lioua Kolsi,Mohamed Bechir Ben Hamida,Walid Hassen,Ahmed Kadhim Hussein,Mohamed Naceur Borjini,S. Sivasankaran,Suvash C. Saha,Mohamed M. Awad,Farshid Fathinia,Habib Ben Aissia
Issue:
Volume 1, Issue 2, August 2015
Pages:
30-43
Received:
19 June 2015
Accepted:
30 June 2015
Published:
2 July 2015
DOI:
10.11648/j.ajme.20150102.12
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Abstract: The two-dimensional laminar natural convective transient flow characteristics in a differentially heated air-filled tall cavity with gradual heating are investigated both experimentally and numerically for various parameters such as Rayleigh number and temperature difference. Experimental computations are performed for temperature difference varying from (∆T = 5°C) to (∆T = 23°C) while the Rayleigh number varies from (Ra = 2929) to (Ra =11772) to cover a wide range of the flow field inside the cavity. The results show that as the Rayleigh number increases the flow becomes unstable. Also, the flow characteristics are observed to be multi-cellular and time variant especially at high Rayleigh numbers. Moreover, numerical computations are performed to compare with the experimental results.Abstract: The two-dimensional laminar natural convective transient flow characteristics in a differentially heated air-filled tall cavity with gradual heating are investigated both experimentally and numerically for various parameters such as Rayleigh number and temperature difference. Experimental computations are performed for temperature difference varyin...Show More
Kaouther Ghachem,Mohamed Bechir Ben Hamida,Chamseddine Maatki,Lioua Kolsi,Mohamed Naceur Borjini,Habib Ben Aissia
Issue:
Volume 1, Issue 2, August 2015
Pages:
44-51
Received:
19 June 2015
Accepted:
30 June 2015
Published:
14 August 2015
DOI:
10.11648/j.ajme.20150102.13
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Abstract: This paper studies the effect of the combined natural convection and radiation on the heat transfer and this, in an inclined solar thermal collector. A 3D numerical code is developed to solve respectively the convection equations according to the vorticity-vector potential formulation and the radiation equation. The discretize schema is the control volume method for the convection and the FTnFVM for the radiative equation. Numerical solutions are obtained for Pr=0.71, Ra=105, and the radiation-conduction parameter (rc) ranging from 0 to ∞. The medium is considered as gray. Indeed, it emits and absorbs heat.Abstract: This paper studies the effect of the combined natural convection and radiation on the heat transfer and this, in an inclined solar thermal collector. A 3D numerical code is developed to solve respectively the convection equations according to the vorticity-vector potential formulation and the radiation equation. The discretize schema is the control...Show More
