C. Ghanshyam

High Voltage Generation for Charging of Liquid Sprays in Air-Assisted Electrostatic Nozzle System

ABSTRACT Electrostatic induction charging has proven itself as one of the best methods adopted in agricultural pesticides spraying. Pesticide droplets get charged while passing through a charging electrode which is connected to a high voltage along with the grounded liquid jet. Negatively charged droplets follow the electric lines of forces and get attracted towards the target which is at ground potential. In this paper, a compact size DC to DC converter is designed and developed to generate high voltage. The circuit consists of two sections, a DC to AC converter and an AC to DC converter, which can also be termed as an inverter and Cockcroft Walton multiplier. The converter utilized a 9.0 volt DC rechargeable battery to give a high voltage output. The converter has been used for spray charging in air-assisted electrostatic nozzle system placed inside the nozzle holder. The results were in good agreement with the theoretical concepts and practices. The designed power supply system showed the output stability at higher frequency range which has optimum ripple and voltage drop when applied with load.

Plant leaf imaging technique for agronomy

Recent physiological studies on nutrition and growth have shown that leaf area is a reliable index of growth factor determining carbohydrate metabolism, yield and quality of crops. Software was developed using image processing toolbox of MATLAB, for calculating parameters of multiple leaves like area, length, width etc. Sample of 50 leaves of various shapes and sizes were used in measurements and results were compared with existing graphical method like grid counting. But grid counting method is very time consuming. So a user friendly Graphical User Interface (GUI) was developed in MATLAB. The leaf area meter developed system is low in cost, easy in operation, high accuracy & portable.

Plausibility of variable coverage high range spraying

Electrostatic force field has been exploited in the development of an air-assisted electrostatic nozzle.Parameters are optimized and engineering design aspects have been addressed.Plausibility of variable coverage high range spraying with simple retrofitted mechanical maneuver.The effects of wind current in electrostatic spraying have been explained.It covers a longer distance with variable coverage, which was not possible earlier. A system for spraying liquid pesticides to crops and orchards combines an induction based electrostatic nozzle and externally air-assisted manually controlled mechanical device. In this paper, an innovative concept has been executed for variable coverage high range spraying through an external air-assistance system, which supplies compressed air to assist the finely divided charged liquid droplets by farming a virtual covering around the fine mist of liquid spray. External air-assistive device consists of movable support for air supplies whose variation of cone angle is from parallel spray center line (0°) to maximum spray cone angle (25°). This provides a means to transport electrostatically charged fine mist of liquid droplets to intended target with variable spray coverage angle of target, applicable in high wind and transient conditions with enhanced performance without degradation of charge-to-mass ratio. The results of applied induction electrification process were characterized by a charge-to-mass ratio as a function of applied voltage, target distance, and wind current. It has been shown that the wind current has an insignificant (p value=0.021615) and significant (p value=0.000325) effects on the performance of the electrostatic nozzle at 99% confidence level with and without external air-assistive mechanical device respectively. The experimental results are in good agreements with proposed concept.

Navigation control of a mobile robotic system in semi-structured and dynamic environment for controlled dose delivery of pesticides

A major portion of the autonomous mobile robotics research has been in the development of reliable means for navigation and control of autonomous systems in a complex, irregular, unstructured and dynamic environment for farm duties such as seeding, pruning, pesticide spraying, reaping etc. Several practices have been established by numerous researchers in the motion planning of mobile robots. This paper presents an ultrasonic multi-sensor fusion based technique for navigation and control of the autonomous mobile robotic system for collision avoidance, target detection and canopy mapping. The autonomous system is a combination of real time monitoring and navigation, detection of the target and canopy mapping which delivers controlled dose of pesticide in a targeted manner according to the information gathered from the sensory attributes of precision farming data set through online and real time monitoring of the objects. Real time monitoring and navigation control, complex algorithm, data acquisition and storage, calculation and processing are designed with motors and sensors interfaced with microcontroller. Test results showed that the ultrasonic sensor fusion technique was capable of performing satisfactory guidance in dynamic environment and desired paths. The sensor fusion navigation was capable of compensating large error and resulting in satisfactory agricultural vehicle guidance.

Prediction of pollution potential of Indian rivers using empirical equation consisting of water quality parameters

Over the years the surface water quality of Indian rivers has been degrading. There are various reasons for the degradation of quality of river waters in Indian conditions. The pollution potential of river water involves various factors such as pH, Conductivity, Dissolved Oxygen, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Coliform and Fecal Coliform. The paper presents an approach to develop an empirical equation to predict the pollution potential of river water. The empirical equation developed uses aforementioned factors as variables. These variables have been assigned various ratings on a scale of 1-3 according to standard pollution potential charts. The pollution potential predicted using this empirical equation is in congruence with the current potential pollution of Indian rivers.

Comparative analyses of prediction models for inactivation of Escherichia coli in carrot juice by means of pulsed electric fields

This paper reports the prediction capacity of various microbial inactivation models to prefigure the bactericidal effect using pulsed electric field (PEF) on liquid food. The aim of study was to compare the various inactivation models based on accuracy and bias factor to find out the most accurate inactivation model for Escherichia coli present in carrot juice treated with PEF. In this study, E. coli suspended in carrot juice was treated with varying pulsed electric field strength for different intervals. The obtained data were utilized for the evaluation of parameters of Bigelow, Peleg, Hülsheger and Weibull inactivation models. Furthermore, secondary models were developed for Hülsheger and Weibull to predict the microbial inactivation at any level of field strength and treatment time. The secondary model for Hülsheger exhibits 5.8% error as compared to the Weibull model having 8.5% error in prediction of death kinetics of E. coli suspended in carrot juice by means of PEF. The comparative analysis of secondary models to forecast the unknown data set unveiled the superior functioning of Hülsheger model.

Study and Identification of Microflora for the Preservation of Orange Juice using Pulsed Electric Field (PEF) Processing

Pulsed Electric Field (PEF) is an emerging nonthermal food processing technology being effective in microbial inactivation without impairing the food quality. This paper demonstrates characterization of microbiota present in liquid food so that effective range of PEF can be set accordingly thus depicting the type of microorganism present, its morphology and its cell wall chemistry. The investigated microorganisms included E.coli, Staphylococcus aureus and Listeria monocytogenes, isolated from spoiled orange juice samples. These were characterized through a series of biochemical tests following microscopic (SEM) & spectroscopic (FTIR) characterization. The results were confirmed with respect to Standard MTCC (Microbial Type Culture Collection) strains (MTCC 614, MTCC 96, and MTCC 657). In comparison to Gram negative bacteria, the Gram positive bacteria are more resistant towards PEF. Larger microbial cells require less intense field strength to undergo an equivalent inactivation as compared to smaller cell...