Browsing by Author "Joseph, A."

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Basic human values of Indian management professionals: a demographic profile
(Inderscience Publishers, 2023) Joseph, A.; Raju, S.; Rofin, T.M.
This study tries to check the degree of basic human values among management professionals in India with considerable cultural and linguistic differences and how it varies across the different demographic influences. We have checked the impact of demographic variables like gender, age, education, type of organisation, place of residence, and work experience on basic human values. Hypotheses testing were conducted using MANOVA. It was inferred that the perception regarding the degree of basic human values differs among different management professionals based on their age, gender, education, type of organisation, and place of residence. Surprisingly, the work experience of the person does not have a significant influence on basic human values. Consequently, we imply that the demographics of an individual carve their basic human values. The findings and inferences of the proposed study will be of great importance to policymakers and recruiting managers to fetch the right candidate. © © 2023 Inderscience Enterprises Ltd.
Deposition of TiN and TiAlN Thin Films on Stainless Steel Tubes by a Cylindrical Magnetron Sputtering Method
(ASTM International, 2021) Trivedi, K.; Rane, R.; Joseph, A.; Arya, S.B.
Titanium nitride (TiN) and titanium aluminum nitride (TiAlN) coatings are very hard materials that are mostly coated on cutting tools to increase the tool life. These coatings have also been successfully applied as a coating material for biomedical applications mainly due to their tribological properties, biocompatibility, and affordable price. In an attempt to develop transition metal nitride coatings on specimens of cylindrical geometry, TiN and TiAlN thin films were deposited successfully on stainless steel tubes using a direct-current cylindrical magnetron cosputtering method. Both types of coatings were uniform in nature and had good adherence to the substrate. TiN and TiAlN thin films were characterized systematically to determine their structure, surface morphology, chemical states, chemical structure, and electrochemical behavior using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and potentiodynamic methods, respectively. The XRD patterns of the TiN and TiAlN coatings indicated (111) preferential orientation. Crosssectional SEM images revealed a columnar growth of the coatings with an arrow-headed geometry. XPS characterization showed the presence of TiN, Titanium dioxide, titanium oxynitride, aluminum oxide, and aluminum nitride phases. Potentiodynamic polarization tests in 3.5 % sodium chloride solution revealed that the TiAlN coating exhibited superior corrosion resistance compared with the TiN coating. Furthermore, TiAlN coating showed 94 % of average absorption in ultraviolet-visible region using photospectrometry. The cylindrical magnetron sputter deposition technique enables development of uniform protective coatings on tubular geometries, which are frequently employed in solar thermal and nuclear applications. © 2021 by ASTM International.
Experimental investigation of the in-plane quasi-static mechanical behaviour of additively-manufactured polyethylene terephthalate/organically modified montmorillonite nanoclay composite auxetic structures
(SAGE Publications Ltd, 2023) Mahesh, V.; Maladkar, P.G.; Sadaram, G.S.S.; Joseph, A.; Mahesh, V.; Harursampath, D.
Apart from the inherent anomalous behaviour under tensile and compressive structures, auxetic structures have shown improved energy absorption characteristics that are of prime interest to various fields of study. This is further exemplified by additive manufacturing (AM) techniques and polymer composites to tailor the shape, geometry and form of these structures. Consequently, this paper aims to characterise the in-plane compressive behaviour and negative Poisson’s ratio (NPR) of the most prominent auxetic structures fabricated additively used polymer nanocomposite materials. The study incorporates the use of glycol-modified polyethylene terephthalate (PETG) and nanocomposites of PETG filled with organically modified montmorillonite (OMMT) nanoclay particles to produce auxetic structures fabricated through fused filament fabrication (FFF). Different structures such as hexagonal re-entrant honeycomb structures, peanut-shaped honeycombs, chiral honeycomb structures and missing rib structures are characterised for their compressive performance through experimental approaches involving mechanical testing and digital image correlation (DIC). Different parameters such as the peak crushing strength, average crushing strength, NPR, specific energy absorption (SEA), and crush force efficiency (CFE) of these structures are evaluated at different strain rates/loading rates for varying concentrations of nanoclay and PETG. It is observed that higher loadings of nanoclay particles lower the compressive strength of the structures. Additionally, the NPR decreases with increasing strain rates and is also influenced by the composition and the resultant stiffness. Moreover, the geometrical parameters of the structure largely influence its strain energy absorption. The results have shown that such material-structure combinations can produce structures of high-performance capabilities suitable for aerospace applications. © The Author(s) 2022.
Machine learning enhanced multi-scale dynamic viscoelastic analysis of 3-D printable PETG nanocomposite filaments: Leveraging FFT-based mesh-free computational homogenization for complex microstructures
(Elsevier B.V., 2025) Aher, Y.; Mahesh, V.; Joseph, A.; Mahesh, V.; Kattimani, S.; Harursampath, D.
The article investigates the influence of organically modified montmorillonite nanoclay (OMMT-NC) and short carbon fibers (SCF) on temperature-dependent mechanical properties of additively manufactured glycol-modified polyethylene terephthalate (PETG) nanocomposites. This work utilizes Dynamic Mechanical Analysis (DMA) to explore the influence of microstructure on the multiscale viscoelastic properties and the resulting stiffness-damping trade-off in porous nanocomposites. Machine learning (ML) and X-ray Micro-Computed Tomography (micro-CT) are employed to bridge the gap between experimental measurements from DMA and computational modelling. A novel mesh-free computational approach, combining fast Fourier transform (FFT)-based homogenization and the Lippmann-Schwinger (LS) method, was applied to analyze the porous heterogeneous microstructures. The analysis of pore geometry and fiber distribution, along with the associated stress-strain behavior, provides valuable information regarding stress concentration at critical material interfaces. The proposed method revealed a higher Von Mises stress and strain in the matrix surrounding the fiber ends, a principal locus of load transmission. Further, the experimental DMA results highlight the importance of considering interfacial adhesion, friction, segmental mobility, and intercalation effects on modulus, Tg, and tan ?. PETG +15 wt % SCF demonstrated high damping (tan ?: 0.19) and a 35 % and 122 % rise in modulus in glassy and rubbery states, respectively. Meanwhile the relative modulus of PETG +1 wt % OMMT-NC + 5 wt % SCF and PETG +3 wt % OMMT-NC + 5 wt % SCF nanocomposites improved by over 41 % in the glassy state. © 2025 Elsevier B.V.
Photocatalytic Degradation of Chlorpyrifos and Tetracycline in Aqueous Medium Using Silver Titanate Perovskite Nanoparticles
(Springer Science and Business Media Deutschland GmbH, 2024) Joseph, A.; Raval, K.; Manirethan, V.
Near-infrared (NIR) active silver titanate perovskite (AgTiO3)-based photocatalysis is a potential method for degrading organic pollutants due to its unique structural features, compositional flexibility, and affordability. Herein, we have synthesized novel NIR-active AgTiO3 nanoparticles with a low band gap of 0.92 eV via the hydrothermal method using Ananas comosus leave extract, which is a major agricultural waste worldwide. The produced AgTiO3 nanoparticles were characterized using Fourier Transform Infrared (FTIR) spectroscopy investigations, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDS). The photocatalytic activities of the AgTiO3 nanoparticles toward the degradation of tetracycline and chlorpyrifos under UV, visible, NIR, and solar light irradiation were carefully examined, and the photocatalytic mechanism was proposed using liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography (HPLC). AgTiO3 nanoparticles completely degraded tetracycline and chlorpyrifos within 27 min and 21 min, respectively. The increased efficiency of AgTiO3 nanoparticles produced by green synthesis over conventional photocatalysts points to a potential advancement avenue for water treatment systems. Furthermore, using agricultural waste like leftover pineapple leaves not only lessens the impact on the environment but also solves the issue of cost when putting these technologies into practice on a larger scale. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.