654 research outputs found
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Computational Modeling and Experimental Evaluation of the Effects of Electrode Geometry and Deposition Target on Electrostatic Spraying Processes
No full textElectrostatic force field application is one of the most promising methods for spraying protective liquid sprays onto the biological surfaces of crops, orchards, vineyards and trees, because electrostatic space charge and image deposition forces enhance the uniformity of spray on the target surface and increases the transfer efficiency, mass transfer and adhesion. The study has been carried out to know the effects of electrode geometry, deposition target and spray cloud through computational modeling using COMSOL Multiphysics. In this work, four different shaped targets, four different geometry of electrodes and four stages of spray cloud are analyzed to know the effects of resultant electric field to charge the conductive liquid sprays. Comparative study of electric field among all the four shaped targets resulted that elliptical target has the maximum resultant electric field followed by conical, spherical and cylindrical target respectively. Similarly in case of electrode geometry, electric field of square electrode with circular cross-section found to be optimum followed by circular electrode with circular cross-section, circular electrode with square cross section and square electrode with square cross section respectively. The experimental results are in good agreement with computational modeling of charging the liquid sprays
Synthesis and energy applications of metal organic frameworks
No full textThe unique and tunable properties of metal organic framework (MOF) provide a new technological opportunity to challenge various issues in energy sectors. This review critically assesses the unique features regarding the synthesis methods of MOFs and discusses their vigorous role in light emitting device and photovoltaic devices. This review article also aims to help upgrade the feasibility of MOFs for the future applications towards energy systems and to provide an outline for the future opportunities in this field
Comparison of Artificial Immune System and Particle Swarm Optimization Techniques for Error Optimization of Machine Vision Based Tool Movements
No full textIn conventional tool positioning technique, sensors embedded in the motion stages provide the accurate tool position information. In this paper, a machine vision based system and image processing technique for motion measurement of lathe tool from two-dimensional sequential images captured using charge coupled device camera having a resolution of 250 microns has been described. An algorithm was developed to calculate the observed distance travelled by the tool from the captured images. As expected, error was observed in the value of the distance traversed by the tool calculated from these images. Optimization of errors due to machine vision system, calibration, environmental factors, etc. in lathe tool movement was carried out using two soft computing techniques, namely, artificial immune system (AIS) and particle swarm optimization (PSO). The results show better capability of AIS over PSO
Experimental Investigation of Machining Parameters Using Rotary Electrode For EDM of HCHCR D2 Steel
No full textIn this work an attempt has been made to correlate usefulness of electrodes during rotary motion. Experiments are conducted to study the effect of different parameter such as peak current and duty cycle on material removal rate and surface finish while
using different rotary electrode such as Copper, Brass and Aluminium. It is observed that using rotary copper electrode for electric discharge machining at low and intermediate values of peak current i.e. 10 and 20A to provide better MRR than that of aluminium and brass at duty cycle 3 and 9 whereas, for high value of peak current i.e. 30A aluminium to be used. At duty cycle 6 aluminium has better MRR at low and intermediate value of peak current i.e. 10 and 20A whereas, copper is used for high value of current i.e. 30A and brass is not acceptable at any value of current and duty cycle because of its poor MRR. SR has lowest value when we use brass electrode for every set of duty cycle. e percentage contribution of input parameter has been calculated using ANOVA table. It showed that current has the maximum effect on all parameter followed by duty cycle and on time
Study and Development of Instrument for Plant Protection Applications Associated with Apple and Picrorhiza kurroa (Kutki) Diseases
No full textIn the present research paper, plant response to the environment and disease monitoring system is presented, which is based on the meteorological approach and digital information and communication technology (ICT). It predicts the growth of kutki or apple fruit diseases such as Apple scab, Marssonina blotch, Red mite pest, etc. This system provides solutions to the farmers to mitigate the disease risk. Growth of apple disease and pests are highly dependent on various environmental parameters such as temperature, relative humidity (RH), leaf wetness, etc., which are measured by developing sensor arrangements and using a prediction model by which the index of infection is calculated. It tells about the severity of risk in crop management. This information can be sent to the farmer's mobile phone and also to the server located at far away from the field using GSM-GPRS (General packet radio service) so that they can easily handle the risk of pest control management. This ICT application consists of both hardware and software tools developed by the author
Single and Multiple Microparticle Trapping Using Non-Gaussian Beams From Optical Fiber Nanoantennas
No full textOptical trapping of dielectric microparticles is reported using an optical tweezers based on two original chemically etched fiber nanoantenna. The nanoantenna converts Gaussian beam into nondiffracting type quasi-Bessel beam, which is used in trapping microparticles. Stable trapping in three distinct positions is observed for an antenna distance of 32.5 μm and for light powers as low as 1.3 mW. Optical trapping properties are studied by applying Boltzmann statistics to the particle position fluctuations. Harmonic trapping potentials with trap stiffness of 3.5 pN μm-1 are observed. The FDTD simulation results on the antenna optics are also included to understand the trapping mechanism
Mobility assistance for patients with Quadriplegia
No full textImmobility often causes psychological and social effects on the person. Since immobility cannot be cured even by using drugs in most cases, it is essential that such people be given a means of mobility which does not let their immobility hinder their day to day life. This paper describes a very feasible mobility solution for the physically impaired people especially those who are suffering from spinal cord injury in the higher levels of C1-C7. Independent Electromyogram( EMG) signals obtained from the neck muscles of the patient using active EMG electrodes have been used to control the direction of movement of the wheelchair . The direction and degree of movement of the neck governs the speed and motion of the motor powered wheelchair. Ultrasonic sensors placed on the wheelchair have been used for obstacle avoidance. Experimental results have shown that the designed solution is very feasible, cost effective and requires very less training of the user
A hybrid particle swarm optimization and artificial immune system algorithm for image enhancement
No full textImage enhancement means to improve the perception of information in images. Histogram equalization (HE) and linear contrast stretching (LCS) are the commonly used methods for image enhancement. But images obtained through these processes, generally, have excessive contrast enhancement due to which they are not suitable for use in fields where brightness is of critical importance. In this paper, a hybrid algorithm based on Particle Swarm Optimization (PSO) along with Negative Selection Algorithm, a model of artificial immune system, is proposed for image enhancement which is achieved by enhancing the intensity of the gray levels of the images. The proposed algorithm is applied to histogram equalized images of lathe tool and MATLAB inbuilt images to verify its effectiveness. The results are compared with conventional enhancement techniques such as HE, LCS and Standard PSO algorithm based image enhancement
In-situ electrochemical synthesis of prussian blue composite with gold nanoparticles and its application in hydrogen peroxide biosensor
No full textThis manuscript presents in-situ electrochemical synthesis of Prussian Blue-gold nanoparticles (PB- AuNPs) composite for application in hydrogen peroxide (H2O2) biosensor. The SEM image clearly showed the presence of AuNPs of size in range of 50 to 200 nm spread on PB matrix. UV-Visible spectra showed absorbance peak at 530 nm corresponding to AuNPs and a hump in 690-740 nm region for PB, confirming the synthesis of composite. The cyclic voltammetry (CV) showed the surface coverage of 3.65 x 10-9 mol/cm2 for pure PB film and 4.33 x 10-9 mol/cm2
for PB-AuNPs film, with diffusion coefficient of 1.19
x 10-9 cm2 /s, and 5.64 x 10-9 cm2 /s respectively. The film thickness is found to be 2.4 x 10-12 cm for PB and 2.9 x 10-12 cm for PB-AuNPs composite. The concentration of redox active centers (Fe+3/+2) is 3.5 moles/cm3
for ITO/PB and 4.1 moles/cm3 for ITO/PB-AuNPs respectively. The CV of ITO/PB showed one redox couple at 0.118 V and 0.215 V, whereas with ITO/PBAuNPs
electrode, two sets of well-defined redox peaks; (i) 0.095 V & 0.135 V and (ii) 0.74 V & 0.78 V were obtained. The faradic current obtained with ITO/PB was 3.6 x 10-3 A and 7.3 x 10-3 A for ITO/PB-AuNPs composite film, respectively. The faradic current was almost double in presence of gold nanoparticles, as compared to pure PB. For H2O2 biosensor, the horse radish peroxidase (HRP) was immobilized on composite film and was used for H2O2 detection. The linearity was obtained from 10 to 90 nM, with sensitivity of 0.73µA/nM and the apparent Km value was 45 nM. The response time of reported biosensor is
20 sec and is stable for about three months
Experimental Investigation of Material Removal and Surface Roughness during Optical Glass Polishing
No full textIt has been a challenge to finish optical glass surfaces due to their hard and brittle nature. Moreover, tight tolerances of surface figure and finish make polishing a more critical operation. This work reports the results of an experimental study performed for full aperture polishing of BK7 optical glass. Flat samples of borosilicate (BK7) glass are polished using an optical pitch polisher and cerium oxide (CeO2) slurry.
Taguchi’s L9 orthogonal array is used for the design of experiments. Abrasive concentration, pressure and overarm speed are considered as variable process parameters. Polishing is performed for duration of 120 minutes for each combination of parameters. Material removal is
measured using the precision weighing balance. Surface roughness was measured using a Form Talysurf PGI 120 profiler. Abrasive slurry concentration is observed to be one of the most significant parameters in the optical polishing process. It affects both the material removal
rate (MRR) and the surface roughness. Pressure applied at the workpiece–polisher interface affects the MRR, but the variation of pressure is not found to affect the surface roughness significantly. Relative motion at the workpiece–polisher interface is also observed to be
significant in defining the final polishing outputs