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Experimental evaluation of interlaminar shear stress of CAJRAL type fibre metal laminates prepared with surface treated aluminium sheet by sobbing technique

Asirvatham A.D., Hynes N.R.J., Selvan P., Vignesh N.J., Jebaraj D.J.J., Benita B.

Archives of Materials Science and Engineering

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2024

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Vol. 125, nr 1

15--21

EN

Purpose: Fiber metal laminates (FML) are a new composite, particularly the CAJRAL type laminate, consisting of aluminium and a carbon/jute/epoxy composite. The present work aims to develop low-density Fiber metal laminates (FML) with good mechanical properties for aerospace applications. Design/methodology/approach: FML combines the good characteristics of metal, such as ductility and durability, with the benefits of fibre composite materials, such as high specific strength, high specific stiffness, good corrosion resistance and fatigue resistance. The present work introduces an FML consisting of aluminium and Carbon/Jute/epoxy layers. The FML was produced by the hand lay-up technique. The aluminium sheets were surface-treated with the sobbing method. Two combinations of laminate sequencing were selected: Ca 0°/Ca 45°/Al/Ju 45° and Ca 0°/Al/Ca 0°/Al/Ju 0°. Findings: The structure characterisation after bending tests is shown and discussed. The three point-bending tests are conducted according to ASTM D 2344 standard specifications. Sample-1 (Ca 0°/Ca 45°/Al/Ju 45°/Ju 45°/Al/Ca 45°/Ca 0°) is a better result. Research limitations/implications: Preliminary studies have shown that the metal layers in the laminates and the composite carbon layer, particularly in the bend area of the laminate, significantly impact the nature of the damage. Laminate indicates the complexity of the degradation process of these materials. Practical implications: The orientation of the reinforcing fibres influences the degree of the laminate structure and affects the ability to form laminates. An important factor influencing the properties of the laminate as a whole is to provide high adhesive properties of the composite-metal connections. Originality/value: By replacing aluminium with jute. It is observed that the tensile and flexure stresses of the CAJRAL with Ca 0°/Ca 45°/Al/Ju 45°/Ju 45°/Al/Ca 45°/Ca 0° are more compared with Ca 0°/Al/Ca 0°/Al/Ju 0°/Ju 0°/Al/Ca 0°/Al/Ca 0°.

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Estimation of enamel removal rate in micro-abrasion based drill-less dentistry

Sujana J. A. J., Sujana N. J., Hynes N. R. J., Jebaraj D. J. J., Sankaranarayanan R., Kumar J. S.

Archives of Materials Science and Engineering

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2023

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Vol. 121, nr 2

80--85

EN

Purpose: Drill less dentistry is painless, riskless, soundless and heatless and is very suitable for dental-related concerns where children are the most affected fraternity. Removing enamel from the teeth at the affected region by conventional drilling mechanism is challenging. The processed region is filled using amalgam or other sources for the occupation. The proceedings are a painful experience for the patients due to heat generation while drilling, which also induces vibrations and related noises. There are higher possibilities for tissue damage and disturbances in the unaffected regions. Air-abrasion-based drill-less dentistry handles such problems in a novel way and provides a comparatively pleasant treatment experience to patients. Design/methodology/approach: The enamel removal rate influences the drill-less dentistry as it empowers to predict the quantum of material that can be abraded while executing the process. The mathematical expression of the enamel removal rate has been estimated based on the basic laws of physics and assumptions. Findings: The current work exhibits mathematical modelling to predict the enamel removal. The expression also reveals that the velocity, density and mass flow rate of abrasive particles has a crucial role in deciding the rate of enamel removal from the tooth. The present mathematical expression provides beneficial inputs to the research fraternity in the dental field. Research limitations/implications: The current mathematical expression has arrived through basic laws of physics and assumptions. The enamel removal rate is estimated using an analytical model, and the current mathematical expression can be improvised through fine-tuning fine. The present preliminary studies could be helpful in developing an accurate predictive model in future. Practical implications: The present research supports drill-less dentistry and provides a mathematical solution in terms of derived formulations in predicting the enamel removal rate, as enamel removal rate plays an essential role in drill-less dentistry. Originality/value: The mathematical expression facilitates the problem handling more practically and efficiently. The mathematical expression is helpful in studying and deciding the processing conditions such as stream velocity, particle density and mass flow rate on effective enamel removal rate from the tooth structure.

3

Pulsed laser deposition of ZnO and MoO3 as reflection prohibitors on photovoltaic cell substrate to enhance the efficiency

Selvan P., Jebaraj D. J. J., Hynes N. R. J.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 113, nr 2

65--71

EN

Purpose: With the ever-growing demand for conventional fuels, the improvement in the efficiency of the photovoltaic system is the need of the hour. Antireflection coatings enhance the availability of solar power by reducing the percentage of light reflected. A new coating has been developed to improve the solar cell's overall efficiency. This study focuses on enhancing the efficiency of the monocrystalline solar cell when a coating of ZnO-MoO3 is applied at a certain thickness. Design/methodology/approach: A layer of ZnO followed by MoO3 is deposited on a Silicon solar cell substrate using a Pulsed Laser Deposition process. Due to the transmissivity d between the two materials, they act as excellent antireflection coating. The layer thickness has been engineered to lie in the maximum absorption spectrum of monocrystalline silicon solar cells, which is between 400 and 800 nanometers. Findings: Based on the calculation of transmissivities for a given layer thickness of coating material, the coating has been done, and the efficiencies of the coated specimen were compared with the uncoated solar cell. The percentage improvement in the electrical efficiency of a single crystalline silicon solar cell with an anti-reflection coating at 1059 W/m2 is about 35.7%. Research limitations/implications: Among the available antireflection coating materials, the combination that provides better efficiency when coated on top of a solar cell is hard to find. Practical implications: This anti-reflection coating could be a better solution to enhance the overall efficiency of the single crystalline silicon solar cell. Originality/value: Although ZnO and MoO3 coatings have been investigated separately for improvement in solar cell efficiency with varying levels of success, the hybrid coating of ZnO/MoO3 with a performance enhancement of 35.7% is a great leap.