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Preparation and coating of nano-ceramic on orthopaedic implant material using electrostatic spray deposition
No full textThe objective of the present manuscript was the synthesis of nano hydroxyapatite (n-HA) and its coating on orthopaedic implant material. The synthesis of n-HA has been achieved using wet chemical method. The elemental analysis and FTIR spectrum confirmed the formation of n-HA having a Ca/P ratio of 1.71. The AFM and XRD results showed the nano dimensions of hydroxyapatite (HA) in the range of 25–35 nm. Scanning electron micrographs (SEM) showed a flake-like structure of n-HA having sharp edges. The n-HA was further coated on orthopaedic implant material (titanium alloy, Ti6Al4V), using the electrostatic spray deposition (EDS) technique. The surface roughness of Ti alloy increased from 2.34 μm to 2.77 μm after coating with n-HA and corrosion resistance improved drastically. XRD pattern of n-HA coated Ti alloy however showed broadening of HA associated peak, reflecting change from crystalline to amorphous phase of n-HA
Investigation of optical properties of mixed ligand directed ZnO luminescent nanoparticles for application in light emitting diodes
No full textDeveloping the heavy metal free QD-LEDs is required to curtail the risks to human beings and environment. Nanoparticles that are ecofriendly, chemically stable, easy to synthesize, nontoxic, biocompatible too are the preferred one. ZnO are biocompatible and low cost semiconductor nanoparticles with tunable band gap and large excitonic binding energy, which make them suitable for LED applications. To achieve the same purpose, this research work is focused on the synthesis of surface modified ZnO nanoparticles for their application in light emitting diodes. The condensation reaction is used to synthesize the ligand and wet chemical precipitation method is used to synthesize surface modified ZnO nanoparticles. The optical properties are evaluated using UV–Vis absorption and fluorescence studies. The optical properties are also investigated in the presence of metal ions and an increased band gap is achieved when Fe3+ ion is added to organic receptor coated ZnO nanoparticles. The stability of ZnO coupled receptor is confirmed theoretically using density functional theory
Influence of Temperature on Reducing Gas Sensing Performance of Nanocrystalline Zinc Ferrite
No full textPure phase, zinc ferrite (ZnFe2O4) nanoparticles were synthesized at lower temperature (80 °C) by auto combustion synthesis method. The resulting ‘as synthesized’ powder was heat treated (HT) at 560 °C for 2 h in air atmosphere. As-synthesized particles had sizes ~10 nm with spherical shape. Further, these spherically shaped nanoparticles tended to change their morphology to hexagonal plate shape with increasing HT temperature. The band gap of the ‘as synthesized’ and HT zinc ferite, as determined by using UV–Vis spectroscopy were found to be 1.92 and 1.86 eV respectively. Gas responses of the ZnFe2O4 nanoparticles were measured by exposing them to ethanol gas vapors. It was found that the zinc ferrite nanoparticles exhibited various sensing responses to ethanol gas at different operating temperature. The best sensitivity was observed at low temperature for ‘as synthesized’ ferrite nanoparticles than HT zinc ferrite nanoparticles. Sensing material that had smaller particle size and larger specific surface area was observed to have larger gas sensitivity and vice-versa
Instability controlled synthesis of tin oxide nanofibers and their gas sensing properties
No full textInstability dependent electrospinning process has been controlled to obtain tin oxide nanofibers with morphological variation. The effect of spinning parameters such as viscosity, conductivity, flow rate, distance and applied voltage on growth rate of different instabilities was simulated and different deposition conditions were defined from the simulation results. The structural morphology was analyzed using X-Ray Diffraction (XRD) and Scanning Electron microscope (SEM). The sensing behavior of different structures was investigated. The branched structure obtained due to axisymmetric instabilities exhibited best sensing performance owing to high surface to volume ratio
Synthesis and characterization of α-Fe2O3 Micro-/Nanorods-modified glassy carbon electrode for electrochemical sensing of nitrobenzene
No full textα-Fe2O3 Micro-/Nanorods were synthesized via a co-precipitation method at room temperature. The obtained products were characterized by XRD, SEM, and BET techniques. XRD analysis showed the formation of α-Fe2O3 Micro-/Nanorods. The nitrobenzene sensing of α-Fe2O3 Micro-/Nanorods-modified glassy carbon (GC) electrode was characterized using a cyclic voltammetric (CV) electrochemical technique. The CV curves exhibited redox peaks with a detection limit of 30.4 ppb. Ip was found to be linearly co-related to nitrobenzene (NB) concentration (R2=0.9916). A substantial enhancement in cathodic peak current (C1), and sensitivity (~446 nA/µM) was observed for the α-Fe2O3 Micro-/Nanorods-modified GC electrode than those of bare electrodes
Design and Development of an Embedded System Based on Wireless Instrumentation Technique to control Environmental Parameters of a Storage Chamber
No full textThe main objective is to design a monitoring system for storage atmosphere. Controlled storage atmosphere
means constant monitoring of storage environment and adjust accordingly to maintain the atmospheric parameter such as temperature, relative humidity etc. Several actuators are used for controlling the above parameters. The design and implementation of this process has been done using PIC 16F877A microcontroller, Zigbee & LABVIEW software. The project provides details about sensing, data acquisition, and controlling the storage atmosphere accordingly
The influence of tumour blood perfusion variability on thermal damage during nanoparticle-assisted thermal therapy
No full textPurpose: This study investigates the influence of blood perfusion variability within a tumour and the surrounding healthy tissue during nanoparticle-assisted thermal therapy. It seeks to define ideal therapeutic parameters for a wide range of perfusion rates to attain the desired thermal damage. Material and methods: Pennes’ bioheat model and the Arrhenius model are used to evaluate the thermal damage for a two-dimensional tumour surrounded by healthy tissue. A wide range of tumour perfusion rates were modelled, ranging from moderate to high perfusion in both a homogenously and a heterogeneously perfused tumour. Results: For low perfusion rates, a temporal variation in blood perfusion does not critically influence the thermal damage. For moderately and highly perfused tumours, temporal variation in blood perfusion extends the thermal damage zone by 25–52% compared to a constant perfusion rate. For the tumour size and perfusion conditions under consideration, the ideal therapeutic parameters were found to be irradiation intensity of 1 W/cm2, and irradiation duration of 105–150 s, for a nanoparticle volume fraction of 0.001%. Conclusions: It is concluded for low perfusion rates that due to shorter therapeutic duration, nanoparticle-assisted thermal therapy is relatively insensitive to changes in the perfusion rate during the therapy. For moderately and highly perfused tumours, a constant perfusion under-predicts the real thermal damage zone. This study concludes that for moderately and highly perfused tumours the spatial as well as temporal blood perfusion dynamics should be carefully accounted for to get a realistic estimate of thermal damage zone
Formation of High-Purity Indium Oxide Nanoparticles and Their Application to Sensitive Detection of Ammonia
No full textHigh-purity In2O3 nanoparticles were recovered from scrap indium tin oxide substrates in a stepwise process involving acidic leaching, liquid-liquid extraction with a phosphine oxide extractant, and combustion of the organic phase. The morphological and structural parameters of the recovered nanoparticles were investigated to support the formation of the desired products. These In2O3 nanoparticles were used for sensitive sensing of ammonia gas using a four-probe
electrode device. The proposed sensor offered very quick response time (around 10 s) and highly sensitive detection of ammonia (at a detection limit of 1 ppm)
Fiber Bragg Grating Sensor for Temperature Measurement in Micro Turning of Optical Surfaces with High Surface Integrity
No full textThis article presents the use of Fiber Bragg Grating (FBG) sensor to measure the temperature induced at the tip of the tool, while micro-face turning of optical surfaces. FBG sensor of 120 μm diameter was mounted near the tip of the tool and the shift in Bragg wavelength due to induced temperature was acquired with the help of an interrogator. The experiments were conducted on a Taylor Hobson DT-250 SPDT machine, over three different optical grade alloys namely Aluminum 6061, OFHC (Oxygen free highly conducting) copper and stainless steel. It was observed that while machining stainless steel, temperature at tool tip was highest and in case of OFHC copper it was lowest. The roughness and waviness of machined optical surfaces were measured using PGI 400 Profilometer. The results confirm that temperature induced in micro cutting and the rate of heat dissipation of work material contributes significantly to optical surface integrity
Conjugation of chlorinated carbon nanotubes with quantum dots for electronic applications
No full textMost of the reported methods for the development of carbon nanotube-quantum dot (CNT-QD) conjugates either use the application of cross-linkers or the treatment of CNT to form highly unstable acylated/thiolated precursor. The present work explores the synthesis of CNT-QD conjugates through simple electrostatic binding between the chlorinated CNTs and amine functionalized CdS QDs. This novel route helps in minimizing the chemical treatment to the CNTs surface. Absorption, infrared and Raman spectroscopic and microscopic studies have proved successful chlorination of the multiwalled CNT and their subsequent electrostatic attachment with QDs. The synthesized nanoconjugate has been electrodeposited as thin film that shows semiconducting behavior