Mapana Journal of Sciences

Thermal Stability Analysis of PbO/ISO-UP Resin Composites

Tue, 19 Mar 2024 00:00:00 +0000

Composites of isophthalate-based unsaturated polyester (ISO-UP) resin with various concentrations of lead monoxide (PbO) filler were fabricated and investigated for degradation kinetics & thermal stability of the composites. The thermogravimetric data have been treated with Freeman-Caroll & Horowitz-Metzger methods, and results were discussed. The filler concentration effect on thermal stability & degradation kinetics of composites were also discussed. The neat sample was observed to exhibit one-stage degradation, while the filled composites underwent degradation at two stages. Further, with the increased filler content in the composite, the initial degradation temperature values (IDT) were found to decrease from 337⁰C for the neat polymer to 304⁰C for 50% filled composite, whereas the presence of filler slows down the degradation process. Among the two classical degradation kinetic theories used, the Freeman-Caroll method yields almost close activation energies from 18.295KJ/mol to 20.029KJ/mol, while the Horowitz-Metzger method yields activation energies from 17.919KJ/mol to 13.198KJ/mol.

Photo-Electrochemical Water Splitting Behaviour of ZnO Phthalocyanine and TiO2 Phthalocyanines

A Cyril, M.K. Anitha, A. Sebastin Thangadurai — Tue, 19 Mar 2024 00:00:00 +0000

This describes a study on the photo-electrochemical water splitting behavior of phthalocyanines of ZnO and TiO₂ as photoelectrocatalysts. Here is a breakdown of the key points of the findings in this study.

Linear Sweep Voltammetry (LSV) studies revealed that the ZnO phthalocyanine photoelectrode showed current density of ~10.8 mA/cm² at 0.8 V (vs. Ag/AgCl) under light illumination and about ~8.8 mA/cm² in the dark. Similarly, the TiO₂ phthalocyanine photoelectrode showed current density of ~10.5 mA/cm² at 0.8 V (vs. Ag/AgCl) under light illumination compared to ~7.8 mA/cm² in the dark.The study's key finding is that the ZnO phthalocyanine demonstrated a higher current density than that of TiO₂ phthalocyanine in both LSV and CA measurements under light illumination.

Forensic Analysis of Strontium and Barium Sulphate as a Perceptive Factor by Non-Destructive Method for Tool Paint

Thangadurai S., Sithi Asma B., Palanimurugan A., Cyril A. — Tue, 19 Mar 2024 00:00:00 +0000

New advances in the growth of research methodologies to evaluate various tools are crucial, so as to create the best evaluation possible about whether a paint residue seized at a crime scene arises from a tool detected. Standard analytical techniques are not used to evaluate the red tools when it comes to the prospective use of X-ray navigators. In this study, the trace amounts of strontium and barium revealed by XRD, the main mineral filler, namely strontium sulphate and barium sulphate, a statistical approach was used, and it can diagnose some forensic tool paint during a home invasion. This work is the best example among others of XRD for enhanced characterisation of tool paints in an effective method.

Electric Elegance: Enhancing Cotton Fabric with Conducting Polypyrrole for Gas Sensing Applications

Vinod Shankar More, B. K. Sakhare, R. P. Tandel, G. G. Padhye, T. N. Ghorude — Tue, 19 Mar 2024 00:00:00 +0000

This work is carried out to study the indigenously developed conducting polymer-based gas sensor for NO₂ detection. The gas sensor is fabricated using conducting polymer such as Polypyrrole (PPy) as the active layer on the cotton fabric surface. The effects of washing on the composition and structure of samples were investigated through the application of XRD and FTIR spectroscopy. XRD analysis revealed notable changes in crystal structure. FTIR analysis provided insights into the molecular bonds present, highlighting variations in the functional groups before and after washing. We evaluated the electrical conductivities of samples before and after washing. The key findings shed light on the effects of washing on the chemical structure of gas-sensing materials, which is critical for maintaining sensor performance. This paper discusses the gas sensing mechanism and configuration of the sensor with a threshold limit value (TLV) of 25 ppm, enabling detection at low ppm concentrations.

Classical Limit in the Double-Slit Experiment for Quantum Particles

K. S. Mallesh, B. A. Kagali — Tue, 19 Mar 2024 00:00:00 +0000

It is well known that the double-slit experiment, under proper conditions, reveals the wave nature of both light and quantum particles like electrons. The wave nature of quantum particles is demonstrated by assuming plane or spherical de Broglie waves to be associated with quantum particles. In this article we deduce the wave nature of material particles starting with proper quantum mechanical amplitudes for propagation as arrived at in the path integral formulation. The classical particle limit of the interference pattern follows right away along the same lines as the corpuscular limit follows from wave optics.

A Study on Cosmological Model of Anisotropic Universe with Electromagnetic Field and Cloud Strings in the Frame Work of General Relativity

Ramprasad Tenneti — Tue, 19 Mar 2024 00:00:00 +0000

In this study, we have investigated the Bianchi type-III anisotropic cosmological model in the presence of cloud strings with the electromagnetic field in the general theory of relativity. Exact solutions of field equations are obtained using the fact that shear scalar is proportional to scalar expansion and constant decelerating parameter, which is derived from the variation law of Hubble parameter proposed by Berman(Nuovo Cimento B 74, 182 (1983))and linearly varying decelerating parameter proposed by Akarsu and Dereli(International Journal of Theoretical Physics, 51,612(2012)). The dynamics and significance of the physical parameters of the model are discussed using a graphical representation of these parameters. The dynamics and significance of the physical parameters of the models are discussed.

Eulerian and Unicursal Soft Graphs

Jinta Jose, Bobin George, Rajesh K. Thumbakara — Tue, 19 Mar 2024 00:00:00 +0000

In 1999, Molodtsov proposed the use of soft sets as a means of managing imprecision and uncertainty in decision making. This methodology provides a means of modelling vague and uncertain information. R. K. Thumbakara and B. George introduced the notion of soft graphs, which offer a parameterized perspective on graphs. This study presents the concept of Eulerian soft graphs and explores some of their characteristics.

Changing and Unchanging the Geodetic Number: Edge Removal

G. Micheal Antony Gnana Santhiyagu, S. Balamurugan, R. Arul Ananthan — Tue, 19 Mar 2024 00:00:00 +0000

Let S be a collection of elements in a vertex set V. If every vertex in a graph G falls on a geodesic connecting two vertices from S, then that graph is said to be a geodesic set. g(G) is the smallest cardinality of the geodesic subset of a graph G is known as the geodetic number. This study investigates how the removal of an edge affects some unique families of graphs' geodetic numbers.

Diversity of Butterflies in All Saints’ College Campus, Thiruvananthapuram, Kerala, Southern India

Siny G. Benjamin, Nandini N. J. — Tue, 19 Mar 2024 00:00:00 +0000

The Butterfly diversity of All Saints’ College campus, Thiruvananthapuram, Kerala, India, was documented for one year from June 2022 to May 2023. The rich floral diversity and water bodies on the campus provided an excellent habitat for butterflies. Overall, 81 species belonging to five families were documented. Rarely spotted butterflies dominated in the abundance studies of diversity. The butterfly diversity density is high on the campus when compared with the diversity studies on other campuses. A number of butterflies are reported from the Nymphalidae family. A comparison of butterfly diversity reported from different locations across the state signifies the importance of conserving habitats and flora for the insects.

Editorial

Manoj B. — Tue, 19 Mar 2024 00:00:00 +0000

Recent Developments on Flexible Materials for Thermoelectrics

Tue, 19 Mar 2024 00:00:00 +0000

In recent decades, thermoelectric materials have gained a significant attention due to their ability to directly convert waste heat into electricity. While extensive research has been focused on enhancing the thermoelectric properties of inorganic bulk materials, a new frontier has emerged in this area as flexible thermoelectric materials. These flexible thermoelectrics are driven by the limitations posed by the rigidity, less functional and toxicity of conventional inorganic thermoelectric materials. Despite notable achievements in the development of high-performance flexible thermoelectric materials, they still pose inferior figure of merit (zT) in comparison to their inorganic counterparts. This review encompasses various aspects of flexible thermoelectric materials including theoretical foundations which highlight the principles that explain the concepts and parameters of thermoelectricity to enhance the overall performance, serving as a foundation for understanding the subsequent developments. Further it is overviewed in detail the corresponding state of the art in development of conducting thermoelectric polymers, inorganic-polymer composites, carbon-based thermoelectric and inorganic thermoelectrics on flexible substrates to enhance their thermoelectric performances. Finally it includes the overlook to the future of flexible thermoelectric for wearable thermoelectrics.