Optimization of Adsorption Parameters for Lead (II) Removal from Wastewater using Box-Behnken Design
Optimization of Al 6063 Button Head Rivet FEM Analysis Subjected to CRYO ECAP and RT ECAP
Effect of (SiC+Gr) Addition on the Corrosion Behavior of Powder Metallurgy Copper MMC
Assessment of Reuse Potential of Low-Grade Iron Ore Fines through Beneficiation Routes
Characterization of Copper MMC Reinforced with SiC and Graphite in Equal Proportion Made by the Powder Metallurgy Route
Evaluation and Comparison of Turning Process Performance during Machining of D2 Steel Material under Two Sustainable Machining Techniques
An Investigation on Recent Trends in Metamaterial Types and its Applications
A Review on Plasma Ion Nitriding (PIN) Process
A Review on Friction and Wear Behaviors of Brake’s Friction Materials
Comparative Parabolic Rate Constant and Coating Properties of Nickel, Cobalt, Iron and Metal Oxide Based Coating: A Review
Electro-Chemical Discharge Machining- A review and Case study
Comparison Of Composite Proton Conducting Polymer Gel Electrolytes Containing Weak Aromatic Acids
Enhancement in Electrical Properties of PEO Based Nano-Composite Gel Electrolytes
Electrical Properties of Nanocomposite Polymer Gels based on PMMA-DMA/DMC-LiCLO2 -SiO2
Effect of Donor Number of Plasticizers on Conductivity of Polymer Electrolytes Containing NH4F
PMMA Based Polymer Gel Electrolyte Containing LiCF3SO3
In this work, the Density Functional Theory (DFT) quantum mechanics computational method has been conducted on Theophylline molecular system. DFT/B3LYP/6-31G and DFT/B3LYP/6-31G** level of theories were implemented in the whole calculations. Theophylline (TP) compound chosen has the chemical formula of C7H8N4O2 and lattice parameters of a=24.612 Å, b=3.8302 Å, c=8.5010 Å and α=β=γ=90°. Geometry optimization calculation has been performed to obtain the equilibrium structure of C7H8N4O2 molecular system. Moreover, the optimized geometry structure has been used to calculate the electronic properties (i.e., total energies, frontier molecular orbital energies, atomic charges, and others) of the studied molecular system. The calculated total energies obtained from DFT/B3LYP/6-31G method is -17438.43 eV, while from DFT/B3LYP/6-31G** method is -17444.53 eV. The HOMO-LUMO energy gaps of C7H8N4O2 molecular system are 5.00 eV and 5.12 eV respectively for DFT/B3LYP/6-31G and DFT/B3LYP/6-31G** level of calculations. The molecular electrostatic potential (MEP) mapped plots obtained from both B3LYP/6-31G and B3LYP/6-31G** methods presented that the regions around the atoms of O1 and O2 possess the negative electrostatic potentials, while the positive electrostatic potential falls on the region of H7 atom. In addition, Fourier Transform Infrared (FT-IR) calculation is also included in this study. All the findings of vibrational frequencies show no surprising feature and has been in accordance with the recorded data.
Sodium fluoro alumino borate glasses with composition (30-x) NaF-xAl2O3-69B2O3-1CuO (where x=0, 5, 7, 10, 12, 15 mol %) were prepared by melt quenching method in which Cu2+ ions are acting as spin probe. EPR spectra were recorded at X - band frequencies with 100 kHz field modulation at room temperature and its resonance peaks shows Cu2+ ions characteristics. From calculated spin Hamiltonian parameters, it has been observed that g∥ >g⊥>ge (ge =2.0023 for free electron) and A∥ >A⊥ indicated that the site around transition metal ion (TM) i.e., Cu2+ ion is tetragonally distorted octahedral and its ground state is d2x - y2 orbital (2B1g state). The number of unpaired Cu2+ ion spins (Ni) participating in resonance and the paramagnetic susceptibility (χ) were also evaluated. Glass composition is also a important factor and its effect shows the variation in spin Hamiltonian parameters. A middle broad absorption (2B1g→ 2B2g) band is observed at 770 nm in the optical spectra. Calculated bonding coefficient revealed the bonding nature between TM ion and its ligand.
Aluminium and its alloys have high strength to weight ratio and are used for variety of applications like automobile industries, aerospace and structural applications, electronic circuits, etc. The manufacturing industry has witnessed significant increase in the use of aluminium alloys due to their unique characteristics of good strength and light weight. Other important properties of aluminium alloys include high thermal and electrical conductivity, good corrosion resistance, low melting point, excellent formability, etc. The present work deals with optimization of process parameters for turning of aluminium alloy Al7068 by varying the composition of Zinc in the alloy. There are different methods for process parameter optimization like Taguchi technique, ANOVA method, fuzzy logic, Response Surface Methodology, etc., but Taguchi technique and ANOVA method are widely used. Taguchi method helps to determine optimal condition with lesser number of experiments. ANOVA approach gives which process parameters have a significant influence on the machining response/outputs. Turning experiments were conducted on a ULTRA LYNX CNC machine. The coolant Ipol Aqua cut 125 has been used for turning operation. Taguchi’s L16 Orthogonal Array has been used to conduct turning experiments on the aluminium Al7068 alloy with varying Zn% composition to get the optimized values of the turning parameters. The turning parameters selected were feed, speed, depth of cut, tool nose radius and material composition which were varied in 4 levels. ANOVA (Analysis of Variance) has been performed to validate the results. The percentage contribution of the turning process parameters on machining outputs such as surface roughness, material removal rate, machining time, machining force and machining power has been determined. ANOVA results indicate that material composition has the highest contribution on surface roughness, material removal rate, machining time, machining force and machining power.
The present scenario in the advancements of materials is the development of composite material. Due to its properties like light weight, corrosion resistance, sustainability against load, ease to fabricate, biodegradability, etc., the composite materials are widely focused by researchers. Many researchers working in the growth of composite materials, used different natural fiber like jute, sisal, kenaf, wood flour, bamboo, etc. They encountered a problem regarding high moisture absorption property of the natural fiber. Due to this hydrophilic nature, bonding between matrix and fiber becomes poor and this reduces the mechanical and physical properties of composite material. To reduce the hydrophilic characteristic of natural fiber, different chemical treatment such as alkalization, acetylation, silane, maleated coupling agent, permanganate, peroxide, isocyanate, sodium chorite, plasma, stearic acid, triazine, fungal are used with different weight percentage concentration. The significance of these in the prepared material characteristics have been studied. Noticeable changes in the chemically treated natural fibers mechanical and physical properties are observed. The aim of this review paper is to focus on the importance of various chemical treatment in the application of natural fiber reinforcement for the better performance of composite materials.
According to survey, the most replaceable or the most frequently worn out part of the vehicle is the brake pad. The present era is dominated by nano-materials. Researchers are forced to discover the potential of nano-particles in day to day application. Nanoparticle is used as composite material because of its intensive interaction with the matrix and the low wear surface of brake pad. Nanoparticle is used as filler in good quality non-asbestos organic (NAO) friction materials (FMs). However, the role of nano-particle in brake pad friction material is difficult due to less findings of nanoparticle in brake pad application. Three NAO friction material brake pads with same constituents but different constituent size of nano-particles were developed. One of the composite has been developed without nano-particle, while other two composites with 5% and 10% nano-particles were developed. These were characterized for mechanical, tribological and physical performance of friction materials. Performance parameters such as recovery ratio, fade ratio, wear resistance, etc., has been used to evaluate the performance of non-asbestos organic brake pad friction materials. Both testing result of the machine and data showed that almost all performance parameters of brake pad friction materials were considerably affected due to nanoparticles. It has been finally stated that nanoparticles have a potential to enhance performance of friction materials significantly.
This paper presents the survey of the particulate reinforced Aluminium Metal Matrix Composites (AMMCs) published in the past two decades. The properties of AMMCs are better than the base aluminium (Al) or its alloy matrix. Due to its advantageous properties it can be used in aerospace, automobile, sports, and marine application. This paper reported the pioneering work carried out by researchers in the field of Al alloys and particulate reinforced AMMCs mainly focusing on the mechanical, tribological and corrosion behaviour of various non-metallics (i.e. B4C, SiC, Al2O3, fly ash, basalt, etc.)particulate reinforced AMMCs. The effects of weight or volume fraction and particles size of the reinforcement on the properties of AMMCs have been discussed in a brief manner. The stir casting process affects the properties and is the most commonly used method for the development of particulate reinforced Metal Matrix Composite (MMC) due to its simplicity and cost effectiveness.