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The geometrical efficiency of a source-to-detector configuration is considered to be necessary in the calculation of the full energy peak efficiency, especially for NaI(Tl) and HPGe gamma-ray spectroscopy detectors. The geometrical efficiency depends on the solid angle subtended by the radioactive sources and the detector surfaces. The present work is basically concerned to establish a new mathematical approach for calculating the solid angle and geometrical efficiency, based on conversion of the geometrical solid angle of a non-axial radioactive point source with respect to a circular surface of the detector to a new equivalent geometry. The equivalent geometry consists of an axial radioactive point source with respect to an arbitrary elliptical surface that lies between the radioactive point source and the circular surface of the detector. This expression was extended to include coaxial radioactive circular disk source. The results were compared with a number of published data to explain how significant this work is in the efficiency calibration procedure for the γ-ray detection systems, especially in case of using isotropic radiating γ-ray sources in the form of point and disk shapes.

The geometrical efficiency of a source-to-detector configuration is considered to be necessary in the calculation of the full energy peak efficiency, especially for NaI(Tl) and HPGe gamma-ray spectroscopy detectors. The geometrical efficiency depends on the solid angle subtended by the radioactive sources and the detector surfaces. The present work is basically concerned to establish a new mathematical approach for calculating the solid angle and geometrical efficiency, based on conversion of the geometrical solid angle of a non-axial radioactive point source with respect to a circular surface of the detector to a new equivalent geometry. The equivalent geometry consists of an axial radioactive point source with respect to an arbitrary elliptical surface that lies between the radioactive point source and the circular surface of the detector. This expression was extended to include coaxial radioactive circular disk source. The results were compared with a number of published data to explain how significant this work is in the efficiency calibration procedure for the γ-ray detection systems, especially in case of using isotropic radiating γ-ray sources in the form of point and disk shapes.

Fungi have unique properties and are used in many areas of agriculture and industry because they can produce different enzymes. This study aims to study the fungal diversity in peat soil from Pontian in Johor, Malaysia. The fungal isolates were described on different culture media and on a new culture medium called EVA medium and were identified using the phenotypical characteristics and molecular properties of the D1/D2 domain of the 28S large subunit ribosomal RNA (28S rRNA) and ITS (ITS1-ITS4) rDNA regions. The results revealed that 14 fungal species (15 isolates) were identified, among them, 6 were categorized as newly isolated strains and recorded in Malaysia; these include Aspergillus arenarioides EAN603, A. iizukae EAN605, Paraconiothyrium brasiliense EAN202, Parengyodontium album EAN602, Penicillium pedernalense EAN604, and Purpureocillium lilacinum EAN601. The cultural, morphological, microstructure, and molecular characteristics of these new strains have been described in this study. It was noted that the EVA medium exhibited a moderate support for fungal growth and sporulation compared to other culture media. Furthermore, the efficiency of the new medium as an enrichment medium to isolate fungi from peat soils with high ligninolytic content was discussed.

Fungi have unique properties and are used in many areas of agriculture and industry because they can produce different enzymes. This study aims to study the fungal diversity in peat soil from Pontian in Johor, Malaysia. The fungal isolates were described on different culture media and on a new culture medium called EVA medium and were identified using the phenotypical characteristics and molecular properties of the D1/D2 domain of the 28S large subunit ribosomal RNA (28S rRNA) and ITS (ITS1-ITS4) rDNA regions. The results revealed that 14 fungal species (15 isolates) were identified, among them, 6 were categorized as newly isolated strains and recorded in Malaysia; these include Aspergillus arenarioides EAN603, A. iizukae EAN605, Paraconiothyrium brasiliense EAN202, Parengyodontium album EAN602, Penicillium pedernalense EAN604, and Purpureocillium lilacinum EAN601. The cultural, morphological, microstructure, and molecular characteristics of these new strains have been described in this study. It was noted that the EVA medium exhibited a moderate support for fungal growth and sporulation compared to other culture media. Furthermore, the efficiency of the new medium as an enrichment medium to isolate fungi from peat soils with high ligninolytic content was discussed.

In this contribution, the magnetohydrodynamic non-Newtonian nanofluid flow through a porous medium in eccentric annuli with peristalsis is investigated. This has been done under the combined effect of viscous dissipation and radiation. The inner annulus is rigid and at rest, while the outer annulus has a sinusoidal wave traveling down its wall. The fundamental equations are modulated under the long wave length assumptions, and a closed form of solution is obtained for the axial velocity. While, homotopy perturbation solution is obtained, which satisfies the energy and nanoparticles equations. Numerical results for the axial velocity, temperature, and nanoparticles phenomena distributions as well as the reduced Nusselt and Sherwood numbers are obtained and tabulated for various parametric conditions.

In this contribution, the magnetohydrodynamic non-Newtonian nanofluid flow through a porous medium in eccentric annuli with peristalsis is investigated. This has been done under the combined effect of viscous dissipation and radiation. The inner annulus is rigid and at rest, while the outer annulus has a sinusoidal wave traveling down its wall. The fundamental equations are modulated under the long wave length assumptions, and a closed form of solution is obtained for the axial velocity. While, homotopy perturbation solution is obtained, which satisfies the energy and nanoparticles equations. Numerical results for the axial velocity, temperature, and nanoparticles phenomena distributions as well as the reduced Nusselt and Sherwood numbers are obtained and tabulated for various parametric conditions.