Measurement and evaluation of whole body vibration of agricultural tractor operator

Exposure of whole body vibration(WBV)influences performance,comfort,and long term health risks of tractor operator.Therefore,measurement and evaluation of WBV parameters should be carried out to find probable effects on the health of tractor operators.In this study,a system was designed to measure the WBV of agricultural tractor operators and evaluated the hazard risks on operator’s body according to the ISO standards,and implementation of the WBV test in the official testing station was also suggested.A tri-axial accelerometer was employed to measure vibrations transmitted to the seated operator body as a whole through the supporting surface of the buttock on four typical farm roads under different speeds.The vector sum A(8)exposures on the rough tracks(earthen and grassland roads)exceeded the action limits of 0.5 m/s2 at a 10.9 km/h forward speed and reached to the action limit value at a 16.0 km/h forward speed on the concrete road.The vector sum of VDV(8)exposures did not exceed the action limits of 9.1 m/s1.75 and was greater on the grassland road.The vector sum Sed(8)exposures values exceeded the moderate probability of an adverse health limit of 0.5 MPa on all farm roads at high forward speeds and exceeded the high probability of an adverse health limit of 0.8 MPa on asphalt,concrete,and grassland roads which should be lower than the exposure limit values as suggested by the ISO and EC standards.The WBV evaluation procedure should be considered for implementation at the official tractor test station,which would response to domestic and international tractor test regulations and improve the market competitiveness.

Physiological Changes in Red Onion Bulbs at Different Storage Temperature

Onion bulbs were stored at five different temperatures to know the storage behavior of onion bulbs. Indian red onion bulbs were kept without wrapping at ambient conditions (25℃ ± 3℃ and 75% RH) and within polyethylene pouch at 2.5℃, 6℃, 7℃ and 13℃ for 60 days of storage period. Weight loss, total soluble solids (TSS), number of sprouted and rotten bulbs were measured at an interval of 10 days throughout storage. The greatest decrease (23.25%) in weight was observed throughout storage for onions stored at ambient conditions. TSS was observed to increase in all samples until 40 days of storage and then decreased up to 60 days. Lowest TSS (14.89 ?Bx) was found in onion stored at ambient conditions at the end of storage. Maximum sprouted (67.25%) and rotten (17.78%) onions were observed for onions stored at 13℃, whereas minimum sprouted and rotten onions were found at 2.5℃ at 60 days of storage. Results also recommend lowest temperatures (2.5℃ - 6℃) for prolong storage life of onion with no detrimental effects.

Climate change impact assessment on three major crops in the north-central region of Bangladesh using DSSAT

The potential consequences of climate change emanated from global warming are very alarming;the greatest concern is the potentially disastrous consequences on crop agriculture and food security in many parts of the world.Bangladesh is a country highly susceptible to climate change,but information in this regard is still inadequate.This study investigated the effects of climate change on three major crops-wheat,potato and rice-in the north-central region of Bangladesh.Two climate change scenarios,A2 and B2,of the Intergovernmental Panel on Climate Change(IPCC)were generated by employing MAGICC/SCENGEN model together with the observed climate data of the region.The growth and yield of the crops were simulated using DSSAT CERES-Wheat,SUBSTOR-Potato and CERES-Rice models under the present and projected future changing climatic conditions.For a predicted 5.32℃ increase in temperature in the year 2100,the yield of wheat,rice and potato would decrease by 47.6%,67.8%and 38.6%,respectively.The increased temperature would accelerate physiological maturity of the crops as reflected by their reduced length of growing season(LGS)by 1.20%to 18.5%.The reduced LGS would reduce seasonal evapotranspiration(ET)of the crops by shortening time-span for ET generation.Due to dominant yield reduction over ET reduction,the water use efficiency(WUE)for grain/tuber and biomass yields would decrease with the changing climate.The reduced crop yields are an indicative of a potential future risk of food security in Bangladesh.The results of this study can therefore guide to adopt coping mechanisms in the light of climate change to ensure future food security of the country.