Journal of Applied Sciences and Emerging Technologies

Numerical Thermal Analysis of Nano Fluid Based Heat Pipe for Electronic Devices

Muhammad Umar Khan — Thu, 11 Jan 2024 00:00:00 +0000

An analytical and numerical model is developed for heat pipe having Magnesium Oxide Nano fluids of concentration 0.5, 1.0 & 1.5%. Heat pipe with the induction of Nano fluids are becoming the preferred choice as a heat sink in electronic devices. These heat pipes are being used due to their higher thermal conductivity, compact design and enhanced life with better efficiency. This study has numerically and experimentally investigated the thermal analysis and thermal management by the induction of Magnesium Oxide (MgO / water) Nano fluids in sintered wick heat pipe. The analytical model is developed with suitable assumptions. The ANSYS FLUENT software has been used for numerical analysis. A comparison of analytical modeling determines the temperature profile result shows that the analytical modelling and numerical modeling results are in good range with the numerical modeling results. There is less than 5% error in both results.

Transition of Signals from Time Sampled Form to Frequency Sampled Form using Transformation Methods

Ahmed Faraz — Thu, 11 Jan 2024 00:00:00 +0000

This research paper deals with the transformation of digital signals from time domain representation to the frequency domain representation. This transformation is completed in three phases, the first phase is transformation from digitally time domain represented signal to sampled stripe set based signal through time sampling procedure and the second phase is transformation from time sampled stripe set based signal to frequency domain represented signal with certain angular frequency and the third phase is from frequency domain represented signal to sampled stripe set formed frequency domain based signal through frequency sampling procedure. The necessity for signal transformation is the industry need for utilization of digital signal processing based devices in wireless communication systems. The models of transformation of digital signals from time domain representation to frequency domain in sampled form are proposed systematically with using classical digital signal processing models. After using and evaluating the mathematical models I got that for odd and fractional values of k, the Fourier transforms of digital signals have real and imaginary part whereas for even values of k, the Fourier transforms of digital signals have only real form.

The recent advancements on metal free catalysts for oxygen evolution reaction (OER)

Thu, 11 Jan 2024 00:00:00 +0000

The catalytic activity of electrocatalysts for water oxidation or the oxygen evolution reaction (OER) has received significant attention in recent years due to its crucial role in various applications such as water splitting, rechargeable metal-air batteries, and fuel cells. Numerous research studies have been dedicated to the advancement of efficient, stable, and cost-effective catalysts for water oxidation, which is a primary focus of the present study in the field of renewable energies. It is the focus of this review to show the latest effort and role of metal-free electrocatalyst including P,N,S and B etc in OER process. This article will be helpful to find stable and efficient electrocatalyst .The others key performance evaluating parameters, which also influence on catalytic efficiency will be summarized. The basic procedure for Nano-particles synthesis will be recalled in detail. Challenges in this field and future predictions will also be highlighted. This review article will help to investigate in developing a finer catalyst and will offer basic understanding of OER through basic spectrum to enhance the stability.

Synthesis of Nano Fibrillated Cellulose blends and their Rheological Behavior using different mixing

Sophia Nawaz Gishkori — Thu, 11 Jan 2024 00:00:00 +0000

The purpose of this study was to reduce the viscosity of Nano fibrillated cellulose by mixing it with a non-ionic polymer such as poly vinyl alcohol and maintaining the dry solid content at the same level. An aqueous solution of poly vinyl alcohol was prepared and it was mixed with Nano fibrillated cellulose at three different concentrations. These were 0.08%, 0.1% and 0.12 %. The effect of different polymer concentrations on the rheology of Nano fibrillated cellulose was investigated. Modular compact rheometer 300 was used in order to obtain rheological data. Two different results were generated. The first one was the shear viscosity versus shear rate and the second one was the complex viscosity versus mixing time. Dispermat VL was used for the mixing of Nano fibrillated cellulose and polyvinyl alcohol. Two impellers with different geometry were used for mixing purpose. Double milling impeller was used with beads. 48 hours of mixing was carried out with dispersion impeller whereas for double milling impeller 5 hours mixing was used. An optical microscope was used in order to study the morphology of mixed samples. Obtained results showed that the viscosity of Nano fibrillated cellulose was reduced at all concentrations of poly vinyl alcohol where as an intermediate concentration of polyvinyl alcohol i.e., 0.1% was most effective compared to the other two concentrations. Moreover, mixing with dispersion impeller showed better results in terms of viscosity reduction as compared to double milling impeller.

Unveiling the Morphology and Composition of Heterogeneous Co, Zn and ferrite Catalysts for Efficient Catalysis

Khurram Shahzad Ayub — Thu, 11 Jan 2024 00:00:00 +0000

In order to explore the possible catalytic activity of Co, Zn ferrite catalysts, the current work explores their morphological and compositional features. The extraordinary surface area was attributed to the development of irregular nanocrystalline particles with sheet-like shapes, as indicated by field emission scanning electron microscopy (FE-SEM) study. The presence and appropriate ratios of Co, Zn, Fe, and O were verified by energy-dispersive X-ray spectroscopy (EDS), reflecting catalyst stoichiometry and purity. The polydispersity of the catalysts was further revealed by high-resolution transmission electron microscopy (HR-TEM) micrographs, which showed a wide range of particle sizes shaped as quasi-spherical, octahedral, and cubic. These results offer insightful information about the catalysts' structural properties and point to their possible utility in a range of catalytic applications particularly for the volatile organic compounds (VOC).