1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
Permanent URI for this communityhttp://localhost:4000/handle/123456789/1
Browse
3 results
Search Results
Item Air assisted sprayer with electrostatic nozzle for coconut palms(Department of Farm Machinery and Power Engineering, Kelappaji College of Agricultural Engineering and Food Technology, Tavanur, 2025-05-09) Athira Prasad; Dhalin, DAn air-assisted electrostatic sprayer prototype suitable for coconut palms was designed and developed. Studies on the important plant parameters, including height of palm, canopy diameter, and angle of leaf orientation, were carried out as the primary step in developing the prototype. The major components of the developed unit are a High Voltage DC (HVDC) System, nozzle unit, liquid delivery unit, and an air-assistance unit. The high-voltage DC system capable of generating voltages in the range of 1 to 10 kV was developed using a Line Output Transformer (LOPT 1010A) coupled with a Metal-- (MOSFET Oxide Semiconductor Field Effect Transistor IRFZ44E). Among major electrostatic spray droplet charging methods, induction with a ring electrode (4.3 mm diameter copper wire) was chosen due to its several advantages over the other methods. The diameter of ring electrode (40, 60, and 90 mm) and the horizontal position (5, 10, and 15 mm) of the electrode in front of the nozzle were optimized under laboratory conditions in terms of charge to mass ratio (CMR) of the developed electrostatic system using a specially pressure of 10.5 kg‧cm designed Faraday Cage apparatus. A high-pressure hydraulic nozzle was selected for the liquid atomization and a double-stage diaphragm pump with a cut-off 2was selected for the liquid supply unit. An Electric Ducted Fan (EDF) was chosen for the air assistance unit. The spray gun comprising both the nozzle and the EDF was mounted on an 8 m long telescopic carbon fiber pole, and all other major components and control units were arranged as a backpack unit for easy handling. Water Sensitive Papers (WSPs) were used to study the effect of electrostatic charging on spray characteristics. The performance evaluation of the developed prototype in terms of deposition, droplet density, spray drift and biological efficacy was carried out under actual field conditions and compared with a conventional sprayer (Rocker sprayer). The field trials were conducted under optimized operating conditions viz. electrode 2), diameter (90 mm), electrode position (10 mm), operating pressure (5 kg‧cm VMD (156 μm), and EDF air flow velocity of 17 m‧s-1. The results concluded that the spray deposition of the developed sprayer has 20.69, 27.23, and 63.95 per cent higher in the adaxial surface at the lower, middle, and upper middle canopy respectively compared to the air-assisted spraying. And 39.05, 22.7, and 84.33 per cent higher with respect to the conventional rocker sprayer. Moreover, electrostatic spraying has 1.81 times more droplet density compared to rocker sprayer, and 1.2 times more than the air-assisted sprayer. The deposition efficiency was calculated as 69.77, 43.09, and 33.86 per cent for the spraying with electrostatic sprayer, air assisted sprayer and rocker sprayer respectively. Spraying with the developed sprayer was able to reduce the Rugose Spiralling Whitefly (RSW) incidence, severity and RSW live colony per leaflets by 32.76, 64.17, and 74.91 per cent respectively. The total cost of the developed prototype was Rs. 22,120/-. The operational cost of the developed electrostatic sprayer was calculated to be ₹151 per hour, significantly lower than that of the conventional rocker sprayer, which stood at ₹231 per hourItem Investigation on design parameters for the development of a pineapple harvester(Department of Farm Machinery and Power Engineering Kelappaji College of Agricultural Engineering and Technology, Tavanur, 2018) Athira Prasad; Shivaji, K PThe pineapple (Ananas comosus) is a tropical fruit with significant economical importance. The mechanisation in the field of pineapple harvesting has become inevitable. Basic information on its cultivation practices and physical and mechanical properties is essential for the design and development of suitable machinery. Cutting energy and cutting force requirement are some of the vital information in the design aspects of mechanical harvester. As brush cutters have bcome very common machinerry used by farmers and different attachments on brush cutter suitable for harvesting paddy, sugarcane and pineapple have already been developed and are used. Hence this study is focused on investigation on desigh parameters for the development of a pineapple harvesting attachment to brush cutter and evaluation of different designs of fruit holders. The curring energy requirement was determined using an impact test rig apparatus. The maximum cutting force was then calculated from the cutting energy. For the mechanical harvesting of pineapple, three fruit holders were designed and fabricated. The holder-A supports the fruit and the distance between the cutting edge and holder is fixed. Holder-1 supports the fruit and it can move with respect to the cutting edge. Holder -2 can grip the fruit but the distance and between the cutting edge and holder is fixed. Holder-3 can grip the fruit and it can move with respect to the cutting edge. The field tests of the holders were then conducted to evaluate their performance in comparison with the existing fruit holder. The average height of a pineapple plant was obtained as 94.57 cm with a standard deviation of 20.62 cm. The average number of leaves was obtainded as 47 with a standard deviation 13.2. The average height of fruit from ground and angle of inclination was observed as 33.2 cm and 38.2 respectively. The eaverage diameter of stem was 26.69 mm with a standard deviation of 8.57 mm. The maxixmum cutting energy and force of pineapple stem was obtained as 18.10 J and 842.70 N respevtively, during the first harvest. In case of pineapple leaves, older leaves require maximum cutting energy of 9.60 J. The field evaluation of fruit holders was conducted and it ws found that the holder-1 with 150 mm diameter blade requires minimum time for harvesting, 132 fruits/h, minimum damages of leaves, 5 nos. and more comfortable in handlilng and operating.Item Climate change and population connectivity of Lakshadweep atolls(Academy of Climate Change Education and Research, Vellanikkara, 2018) Athira Prasad; Sreenath, K RLakshadweep is the only atoll type reefs in the territory of India. Since Indian Ocean is the warmest among tropical oceans, Indian corals reefs are vulnerable to the impact of climate change. Coral connectivity helps in maintaining the resilience capacity of sensitive coral reefs. However, shifts in global temperature will strongly influence the period of larval duration and hence the connectivity between the reefs. This study utilised the Mann Kendall trend analysis and Empirical Orthogonal Formula to study the trend of sea surface temperature and salinity over the region. Current study revealed a warming trend of sea surface temperature of Lakshadweep waters. Empirical orthogonal function indicates opposite temperature and salinity modes in the Indian Ocean region which encompasses the Lakshadweep waters. Spatio temporal dipoles identified are surmised to be due to the influence of global climatic phenomenon like El Niño and Indian Ocean Dipole. The study also tries to understand the relationship between larval connectivity and climate. Our findings implies that climate change has a significant influence on larvae and in turn affecting the journey to their corresponding settlement reef. Resilient reefs act as the source for seeding the bleached or destroyed reefs by larval dispersal. Knowledge on the changes of larval connectivity between the reefs can help in taking important decisions during the interpretation and implementation of resilience based management tools in a coral reef. Identifying the pattern of settlement and population connectivity supports in making new Marine Protected areas.