Addressing Bioprinting Challenges in Tissue Engineering
Synthesis of Zinc Oxide Nanoflower using Egg Shell Membrane as Template
In Vitro and in Vivo Experiment of Antibacterial Silver Nanoparticle-Functionalized Bone Grafting Replacements
Biocompatibility in Orthopedic Implants: Advancements and Challenges
Contemporary Approaches towards Emerging Visual Prosthesis Technologies
An Investigation on Recent Trends in Metamaterial Types and its Applications
A Review on Plasma Ion Nitriding (PIN) Process
Comparative Parabolic Rate Constant and Coating Properties of Nickel, Cobalt, Iron and Metal Oxide Based Coating: A Review
A Review on Friction and Wear Behaviors of Brake’s Friction Materials
Electro-Chemical Discharge Machining- A review and Case study
Electrical Properties of Nanocomposite Polymer Gels based on PMMA-DMA/DMC-LiCLO2 -SiO2
Comparison Of Composite Proton Conducting Polymer Gel Electrolytes Containing Weak Aromatic Acids
Enhancement in Electrical Properties of PEO Based Nano-Composite Gel Electrolytes
Effect of Donor Number of Plasticizers on Conductivity of Polymer Electrolytes Containing NH4F
PMMA Based Polymer Gel Electrolyte Containing LiCF3SO3
A very simple and economic chemical bath deposition method has been used here for the synthesis of CuInS2 (CIS) thin films on glass substrate at 45o C. The purpose of the present work is to synthesize a thin film of CuInS2 which must have high absorption coefficient in the visible range, high value of photoconductive gain which increases the mobility and life time of charge carriers and can be used as a hetero-junction in solar cells or photovoltaic devices. The synthesized sample is characterized with X-ray Diffractometer (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-rays (EDX) and Ultraviolet Visible Spectrophotometer (UV-VIS). The synthesized film is having chalcopyrite structure. Lattice constants, a=5.517 Å and c=11.11 Å, have been obtained which matched well to the reported values. Synthesized particles are spherical in shape and agglomeration of particles can be viewed clearly in SEM images. The chemical composition of the synthesized film of CIS has been analyzed by using Energy Dispersive X-Ray Analysis (EDAX). The transmittance of the deposited film is high between 600-650 nm (visible region). The value of absorption coefficient is found to be in the order 5 -1 of 10 cm in the visible region. Photoluminescence spectrum (PL) is recorded by exciting the sample at 450 nm between 300-900 nm. A strong emission peak is obtained in 620 nm (Red band emission) in the IR region. The dark current varies linearly with voltage. The photoconductive gain obtained for the synthesized sample is ~104 .
Composites comprising of an active phase of ferroelectric ceramic and a polymer matrix have recently found numerous sensory and energy storage applications. However, it remains a major challenge to further improve their dielectric and electromechanical response at low loading of ceramics without losing their flexibility. The objective of this research work is to prepare three-phase flexible composites by incorporation of ZnO nanoparticles with various weight fractions into ceramic –polymer matrix, and analyzing the effect of these nano-fillers for optimizing piezoelectric and dielectric properties for various applications. This research aims at employing ZnO nanoparticles to develop highly sensitive piezoelectric composites for vibration / pressure sensing applications and electric energy storage devices by virtue of their significant dielectric and piezoelectric properties. Three phase composites consisting of Polyvinylbutyral (PVB) as host polymer matrix, ceramic Lead Zirconate Titanate (PZT) as active piezoelectric phase and ZnO nanoparticles as third phase with vol% ranging from 1% to 12% were prepared using hot-press technique. The structural analysis of three phase composites PVB/PZT/ZnO were carried out by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). Addition of ZnO nanoparticles forms a percolative network in the composites resulting in enhancement of the electrical conductivity. The percolation threshold was obtained at 6 vol% of ZnO nanoparticles. A significant increase in the piezoelectric properties (d from 25 pC/N to 180 pC/N) of the composites was 33 obtained just near the percolation threshold. ZnO nanoparticles contribute to piezoelectric coefficient by virtue of its noncentro symmetric structure and also by facilitating effective DC poling due to the creation of percolative continuity near percolation threshold. Variation of AC conductivity with frequency and temperature near percolation threshold suggests that hopping and tunneling are the dominating conduction mechanisms in these three phase composites. Experimental results were explained in the percolation transition region using percolation theory and models. These composites are flexible and can be fabricated into various shapes.
Samarium and Zirconium substituted Mg-Mn ferrites having the chemical compositions Mg0.95 Mn0.05Sm2xFe2-2xO4 and Mg0.95 Mn0.05+xZrxFe2-2xO4 are prepared; where x varies 0.0 to 0.5 in steps of 0.1. These are prepared by the standard conventional ceramic method to obtain bulk size materials. Nanosize ferrites are synthesized by citrate sol-gel auto combustion method. These are characterized with X-Ray Diffraction (XRD); spectroscopic studies have been carried out by Fourier-transform Infrared Spectroscopy (FTIR) and Electron Spin Resonance (ESR) spectroscopy techniques. The observed values of nano-size materials absorption bands are compared with bulk size materials for both the substituents. Through ESR measurements, g- factor, line width, and resonance field values have been evaluated; which are interpreted based on the significant role played by the orbital angular momentum. The decrease of resonance line width shows an advantage of the materials to have power applications (cores of transformers) by resulting in low electric loss. The main objective of this paper is spectroscopic study. In future, the spectral study may play an important tool to understand and study multiferroic behavior of Sm/Zr substituted Mg-Mn ferrites.
In this review paper, an effort has been made to understand the plasma ion nitriding process and other existing nitriding processes used in industries. The solubility of nitrogen atoms in the steel matrix have been explained through Fe-N system. The formation of different stable and metastable compounds during nitriding process has been discussed. Different types of nitriding processes have been thoroughly reviewed with their advantages and disadvantages. It was found that plasma ion nitriding process is more reliable as compared to other existing processes in use. Important results of diagnostics and its applications to improve the mechanical and chemical (corrosion) properties of ferrous and non ferrous alloys have been discussed. It was found that N2+, N+ , NH, Hα , and Hβ species exist in the plasma nitriding process, but nitrogen ions (N+) was the most dominant species. Hydrogen plays a significant role in the plasma nitriding process. It was reported that surface hardness and case depth were maximum for the gas ratio of 10% N2 and 90% H2 . The effect of various plasma nitriding process parameters and role of various alloying elements in the plasma nitriding process have been also discussed. If the steel has strong nitride forming elements (Cr, Al, Mo, etc.) under low concentration (~ 1-2%), the diffusion depth and hardness will be more. In the non-ferrous alloys, plasma nitrided samples have two or three distinct layers that depends on the plasma reactivity. Nitrided layer increases only until the critical time and temperature (4500C) were reached.
Hot corrosion is a major problem in engines, steam generators, steam turbine and thermal power plants. The coating is one of the effective methods to reduce hot corrosion. However, better understanding of the hot corrosion performance of thermal spray coating on a different substrate at different temperature and environment, is required to reduce maximum hot corrosion. This paper summarizes the behavior of Ni, Co, Fe, and metal oxide based coating in the simulated boiler environment. The consolidated results of coating properties such as coating hardness, porosity, thickness and parabolic constant has also been detailed with emphasis on corrosion and its mechanism.
The friction brake pads are an important component in the braking system of an automotive. As there is conversion of kinetic energy to heat energy, temperature of friction pair increases which causes coefficient of friction to decrease. This paper gives information about the work done by many researchers to stabilize the coefficient of friction and to decrease the wear of the friction brake pads by taking different combination of friction material. Most of the researchers have proved that, initially coefficient of friction increases up to certain temperature, then it decreases which causes poor friction performance of the Brake.
Electrochemical Discharge Machining (ECDM) is an emerging non-traditional machining process, which combines the advantages of both electric discharge machining and electrochemical machining. It is used in micromachining nonconductive materials such as glass, ceramics and composites. In recent years, the demand of non-conductive materials has grown rapidly in medical, optical, electrical and aerospace applications. As these applications require machining with high accuracy and high reliability, ECDM has great scope in this area. There are some other methods that can machine nonconductive materials but have certain limitations also. Recently, ECDM is a developing process and researchers are continuously trying to develop and modify it as a better solution to machine non-conducting materials. In the current paper, a study on continuous improvements in ECDM in machining of glass, ceramics, composites and hybridization of ECDM have been carried out with their effect on Material Removal Rate (MRR), Surface Finish and Tool Wear Rate (TWR). It was further evidenced that semiconductors and composites were less researched. A case study on machining of glass has also been presented, wherein it is illustrated that increase in applied voltage and electrolyte concentration increases the MRR.