International Journal of Engineering and Applied Physics

Comparative Study of Gamma Ray and Neutron Radiation on Some Electrical Properties of n-CdSe/p-Si Photodiodes.

zainab hamoo, Laith AL Taan, Laith Najam — Fri, 26 Sep 2025 00:00:00 +0000

Cadmium Selenide (CdSe) thin films were prepared on silicon(p-type) substrates using the pulsed laser deposition technique (PLD). They were then annealed at 300 ºC for one hour to get diodes used as a visible light detector. Four diodes were subjected to four different intervals of gamma radiation emitted from the ²²⁶Ra source. For comparison, four of these diodes were subjected to four different intervals of neutron radiation using a ( ²⁴¹Am -¹⁰Be) source; the other diodes were kept without exposure to irradiation. I-V measurements studied the electrical properties of these samples. Results of gamma-irradiated devices show that dark current decreases for the irradiated thin films. Forward current under illumination increases when exposed to small gamma radiation values and then decreases with higher exposure values. While the value of reverse current increases with the irradiation. The results of I-V characteristics for neutron irradiation devices show that the value of current under illumination increases when exposed to small values of neutron radiation, then it decreases with higher values of exposure. However, dark current decreases significantly with irradiation. The effect of the gamma and neutron irradiation was clear on the response/recovery period for all irradiated devices. However, it was more profound in the response/recovery time of pristine devices. Also, the photo-responsivity of the pristine device was larger than that of the irradiated devices, and it decreased with increasing absorbed doses of gamma and neutron radiation.

On the Dynamics and Heat Transfer of a Conducting Droplet during Electrospraying in the Dripping Mode

Reza Khanpour, Pedram Pournaderi — Fri, 26 Sep 2025 00:00:00 +0000

In this study, the influence of an applied electric field on the hydrodynamic and heat transfer of a conducting liquid exiting from a nozzle in the dripping regime is investigated. The flow and energy equations along with the electrostatic equations are solved to simulate this problem. The sharp formulation of the level set technique is implemented to capture the interface accurately. Subjected to an electric field, the liquid is exited faster and its elongation before detachment of the droplet is increased. Also, after the first droplet detaches, the liquid returns towards the nozzle. The length of the exited liquid after returning towards the nozzle increases under an electric field. Therefore, under electric stresses, the droplet formation occurs faster due to the rapid exit and more elongation of the liquid. Also, the size of the formed droplet is reduced with electric field intensity. Under an electric field, the heat transfer rate enhances rapidly in a short time interval before droplet detachment. The total heat transferred to the liquid exited from the nozzle is reduced by increasing the electric field intensity.

Quantum Feature Of Branched Hamiltonians

Dibyendu Ghosh — Fri, 26 Sep 2025 00:00:00 +0000

We point out that a quadratic Liénard-type equation, when appropriately interpreted, exhibits branching behavior as a consequence of the double-valued nature of its governing Hamiltonian. Under a suitable approximation involving the coupling constant, we derive the corresponding quantum mechanical model, which is characterized by a momentum-dependent effective mass function.

The role of beam polarization on the quality of digital holograms

David Ekuwom Kaile, Stephen maina Njoroge, Geofrey Kihara Rurimo — Sat, 27 Sep 2025 00:00:00 +0000

Holography is an imaging technique that has attracted much attention since its inception due to its potential of recording three-dimensional images. As a result, the technique has been applied in fields like interferometry. However, its recording relied on the use of non-polarized sensitive materials which have been limited to the isotropic materials. In this study, we report the role of beam polarization on quality of holograms in respect to important parameters such as; the distance of the Charge Coupled Device from the object and variation of polarization angle. By varying the distance of the camera from the object, a distance of 15cm was clearly noticed to have produced holograms with a more comprehensive set of light wave characteristics; intensity, phase, and polarization state. We have also managed to record and reconstruct holograms at different polarization angles with significant impact on holograms at 0?, 15?, 30? and 45? whose amplitude and phase information was extracted at an optimum distance of 15cm. By comparing the results from these angles, holograms at 45? were of high quality. This advancement not only enhances the visibility of objects that are otherwise obscured or low contrast but also broadens the application of holography beyond isotropic materials.

Stability analysis of double-diffusive convection in couple-stress Hall fluid

Pardeep Kumar — Thu, 25 Sep 2025 00:00:00 +0000

The aim of the present work was to study the effects of uniform horizontal magnetic field and Hall currents on the double-diffusive convection in couple-stress fluid through permeable media. Following the linearized stability theory, Boussinesq approximation and normal mode analysis, the dispersion relation is obtained. The stationary convection, stability of the system and oscillatory modes are discussed. For the case of stationary convection, the stable solute gradient and magnetic field postpones the onset of convection while the Hall currents hasten the onset of convection. The medium permeability and couple-stress both postpone and hasten the onset of convection depending on the Hall parameter M. The stable solute gradient and the magnetic field (and corresponding Hall currents) are found to introduce oscillatory modes in the system, which were non-existent in their absence. The sufficient conditions for the non-existence of overstability are also obtained.