ABSTRACT Tractor mufflers constructed with amalgamation of perforated ducts, baffles or perforated baffles and expansion chambers for acoustic attenuation are commonly used. Poorly designed mufflers provide limited noise reduction and high back pressure, resulting in low fuel efficiency. Sound pressure mapping technique was adopted to identify major contributor of noise for a 47.6 PS tractor. An experiment was carried out to evaluate different muffler designs with regard to sound pressure levels and exhaust back pressure at varying operating conditions. Each muffler design produced noise greater that 90 dBA Leq at operator’s ear level at rated engine speed, and was more than the exposure limit of noise for 8-h work day recommended by ISO and OSHA. Long exposure of this noise might cause occupational disease to operator. Noise reduction was observed in one of the mufflers near rated engine speed with low back pressure with better fuel efficiency. Sound pressure at operator ear level, back pressure and fuel consumption were found within 90.3-92.8 dBA, 1.765-2.157 kPa and 2.65-3.35 l.h-1, respectively, near engine rated speed.
ABSTRACT A six-row oscillating-type garlic harvester was designed and developed for timely harvest of garlic crop. The developed garlic harvester consisted of a digging unit and a soil separating unit. The digging unit consisted of a rectangular shaped digger blade with length, width and thickness of 900 mm, 200 mm and 10 mm, respectively. The soil separation unit had an oscillating rake of 1000 mm length and 900 mm width with 10 mm diameter rods spaced at 50 mm. PTO power was used to operate the soil separator at constant amplitude of 10 mm with 540±10 rpm of a camshaft. The machine performed satisfactorily during field evaluation in sandy loam soil. The highest harvesting percentage was 98.07 % with mean damage of garlic bulb of 4.23 %, maximum soil separation index of 0.20, average power requirement of 5.74 kW and field capacity of 0. 32 ha.h-1 with field efficiency of 80 per cent.
ABSTRACT Low capacities of double roller (DR) gins provides an economic barrier to its widespread application. Feeding mechanism to DR gin plays a significant role in enhancing ginning efficiency. Saw band cylinder-type single-locking feeder was developed with an aim to unlock the cotton bolls and maintain constant feeding rate of individual locules. It comprised of twin regulator, reservoir box, saw band cylinders and feeding apron. It regulated feed rate to about 220-240 kg.h-1. The performance was evaluated in comparison to conventional feeding system. Saw band cylinder speed and cotton moisture content were optimized by using RSM. Quadratic equations for prediction of ginning output and specific energy were generated by using RSM. The ginning output and reduction in bulk density increased by 6.47 % and 22.57 %, respectively, whereas the specific energy decreased by 3.25 per cent. Multiple response analysis showed the optimum levels of moisture content of 7.32 % (w.b.) and saw cylinder speed of 200 rpm with desirability of 0.936 by maximazing output and minimizing specific energy. Cotton quality was found to improve in terms of colour grade due to increase in degree of reflectance and reduction in yellowness.
ABSTRACT The influence of root age and moisture content on compressive strength properties of an improved (TMS 30572) and a local (TME 7) cassava cultivar were investigated. Roots harvested at 12, 15 and 18 months after planting (MAP) were used to determine stress at peak, energy to break and Young’s modulus of the roots at moisture contents of 50 %, 55 %, 60 %, 65 % and 70 % (w.b.). Mean stress at peak, energy to break and Young’s modulus of TMS 30572 ranged from 0.61 – 0.88 N.mm-2, 0.89 – 1.13 N.m and 0.92 – 0.84 N.mm-2; 4.80 – 6.67 N.mm-2, 5.99 – 9.21 N.m and 4.55 – 5.11 N.mm-2; and 4.81 – 9.28 N.mm-2, 5.27 – 5.77 N.m and 5.68 – 8.84 N.mm-2at 12, 15 and 18 MAP, respectively. Corresponding values for TME 7 ranged from 0.41 – 1.06 N.mm-2, 0.95 – 1.15 N.m and 1.07 – 1.30 N.mm-2; 3.23 – 8.18 N.mm-2, 5.70 – 8.37 N.m, 5.56 – 8.04 N.mm-2; and 3.22 – 6.96 N.mm-2, 4.25 – 5.58 N.m and 6.69 – 8.38 N.mm-2, respectively. Second-order polynomials described the behaviours of the roots. Root age, and not moisture content, influenced the strength of TME 7 roots, while none of the parameters studied influenced toughness and stiffness (p>0.05). Neither age nor moisture content significantly affected the toughness and stiffness of the roots of the two varieties.
ABSTRACT Engineering properties of grain and kernel are required to design crop production, material handling and processing equipment. A study was conducted to determine the properties of grain and kernel of Panicum miliaceum at different moisture contents in range of 6.5−26.5 % (d.b.). The length, width, thickness and geometric mean diameter of Panicum miliaceum were observed in the range of 2.22−2.36 mm, 2.08−2.24 mm, 1.93−2.21 mm, 2.07−2.27 mm for grain and 1.87−1.98 mm, 1.73−1.97 mm, 1.63−1.80 mm, 1.74−1.91 mm for kernel, respectively. Sphericity ranged between 0.93−0.97 for the grain, and 0.93−0.96 for the kernel. Surface area, volume and thousand-grain weight increased from 12.73 mm2 to 15.64 mm2, 4.25 mm2 to 5.80 mm3, 5.25 g to 6.70 g for grain; and 8.94 mm3 to 11.14 mm2, 2.50 mm3 to 3.50 mm3, 3.21 g to 4.15 g for kernel, respectively. True density of grain and kernel increased with increase in moisture content. Bulk density decreased from 765.5 kg.m-3 to 697.57 kg.m-3. Similarly, in case of kernel, bulk density decreased from 845.33 kg.m-3 to 724.97 kg.m-3. Terminal velocity of grain and kernel ranged from 1.68 m.s-1 to 2.77 m.s-1 and 0.80 m.s-1 to 1.89 m.s-1, respectively and increasing trend was observed with moisture content. The coefficient of internal friction of grain and kernel increased with increase in moisture content from 0.48 to 0.68 and 0.69 to 0.90, respectively. The geometric, gravimetric, aerodynamic and frictional properties of grain and kernel of Panicum miliaceum at different moisture contents were found to be different at 5 % significance level.
ABSTRACT Soil degradation is a severe environmental problem confronting the world today. A study was undertaken to apply revised universal soil loss equation (RUSLE) to estimate the soil erosion and effect of land use and land cover on soil erosion in Krishna lower sub-basin using Remote Sensing and GIS. Spatial map of each RUSLE parameters was derived in Arc GIS 10.1 and ERDAS IMAGINE 9.3 for the 11317.36 km2 Krishna lower sub-basin catchment in Andhra Pradesh. The values of R, K, LS, C, P factors of the catchment area were used to generate soil erosion spatial maps. The study showed that the average annual soil loss was sensitive to rainfall factor, R, land use and land cover. The computed maximum annual soil erosion for the years 1993 to 2015 was 28.69 t.ha-1. yr-1. Severe erosion was found in settlements, wasteland and during rabi crop. The estimated soil loss from “high” to “very high” occurred in scrubland. Moderate erosion occurred in double/triple cropping area, and slight erosion occurred in forest and during kharif crop.
ABSTRACT The knowledge of wetted width, depth and maximum wetted width beneath the surface of soil is required in design and management of an efficient drip irrigation system, which can largely be controlled by emitter discharge and time of irrigation. Temporal movement of wetting in horizontal and vertical directions under surface point source was studied in acrylic tank at 0.5 l.h-1, 1.0 l.h-1, 2.0 l.h-1 and 4.0 l.h-1 emitter discharges in vertisols. However, a constant volume was applied in each run. Power equation based models were developed using results obtained for temporal changes in parameters of wetting geometry like the horizontal surface wetting width (Bs), maximum wetting depth (d), maximum horizontal wetting width (B) at high value of correlation. The maximum wetted radius at the soil surface as well as beneath the soil surface increased with the increase in emitter discharge rate. The maximum wetting radius at soil surface was found to be 113 mm, 115 mm, 132 mm and 134 mm at discharge rate of 0.5 l.h-1, 1.0 l.h-1, 2.0 l.h-1 and 4.0 l.h-1, respectively. The maximum wetted depth did not increase with increase in emitter discharge rate. It covered distance of 133 mm, 119 mm, 119 mm and 119 mm with emitter discharge rates of 0.5 l.h-1, 1.0 l.h-1, 2.0 l.h-1 and 4.0 l.h-1, respectively.