Showing papers in "Journal of Agricultural Engineering Research in 1981"

TL;DR: A rotary atomizer can produce sprays with narrow ranges of drop size either by forming drops directly at its edge, or by the disintegration of liquid ligaments formed from the edge as discussed by the authors.

TL;DR: In this paper, the authors developed a mathematical simulation of the energy balance at the covering surface; the solution of the relevant equations yields values for the magnitude of each of the transfer processes involved and enables the total rate of heat loss to be calculated.

TL;DR: In this paper, a model based on non-equilibrium thermodynamics was proposed to predict single kernel drying and rewetting rates and center temperatures in the dry-bulb range between 26·7 and 87·8°C and moisture contents between 0·1 and 0·35 dry basis.

TL;DR: In this article, the authors considered the soil failure caused by a rigid tine and the associated draught force characteristics in the light of the concepts of the critical state model of soil mechanics.

TL;DR: In this article, a semi-automatic Magness-Taylor probe is described for testing the resistance of soft fruit and other produce to penetration with a Magness Taylor probe, and having the advantage of needing no adjustment for fruit size and weight.

TL;DR: In this article, the magnitude of the forces on the foot and leg of a mole plough are presented for a wide range of soils together with the effects of the expander, sliding beam, forward speed and leg rake angle.

TL;DR: In this paper, a set of 5 penetrometer probes with diameters ranging from 1·000 to 2·000 mm was used on remoulded and undisturbed field soils.

TL;DR: In this article, the authors investigated inter-row and intra-row weed control by a hoe-ridger, as influenced by soil type, plant height, working depth, tool position and the weather after cultivation.

TL;DR: In this article, an electrical analogue was used to investigate the influence of emissivity and transmissivity of the screen on both the transfer of radiation and screen temperature, and the results obtained for materials of potential use a screens were presented.

TL;DR: A linear programming model of an arable farm has been developed for the use of researchers or engineers developing new machines and techniques as discussed by the authors, which assesses, within a range of farm conditions, the economic and technical bounds within which a machine must operate if it is to be commercially viable.

TL;DR: In this article, the steering of a tractor while ploughing and turning at a headland is controlled by a microprocessor-based unit, which is used for position finding and for steering the tractor just before and during the headland turn.

TL;DR: In this paper, the diffuse spectral reflectance of potato tubers has been measured in the visible red and near-infrared bands and it has been shown that the range of spectral types recorded from tubers suffering from a number of defects can be accounted for almost entirely by the interaction of only three causative agencies.

TL;DR: In this paper, the effect of vehicle speed on soil compaction caused by pneumatic tyres has been investigated by means of a partial simulation experiment in the laboratory and by measuring bulk density changes in field sites caused by wheel compaction.

TL;DR: In this article, the results of a laboratory scale experiment in which pig slurry was treated aerobically in a continuously fed, 151 fermenter operating at a temperature of 55°C were presented.

TL;DR: In this paper, the steepest slope which a 2-wheel drive tractor can safely descend usually determines that on which it can travel safely in any direction, and this is also often the case with a 4-wheel driven machine.

TL;DR: In this article, the authors describe a series of soil tank experiments in which the draught and total power requirements of a soil-cutting blade were measured with sinusoidal vibration applied in the direction of travel.

TL;DR: In this article, a series of milling tests were carried out with long-and bold-grained rice, IR 36, using a friction laboratory mill, and the results showed that no reduction in the percentage of broken rice was achieved by 2-stage milling, i.e., husking by a rubber roll huller and then polishing by a mill.

TL;DR: In this paper, the slip of the rear traction wheels with respect to the front wheels was found using photo-transistors and electronic circuits, and an analogue output of the slip activated a 12 V/d.c. motor whenever the slip deviated from the desired (set) level.

TL;DR: A mobile rainfall simulator was developed for use in small plot field experiments as discussed by the authors, which was based on an oscillating boom housing a series of V-jet nozzles to which the water supply was periodically interrupted.

TL;DR: In this article, the authors compared the predictions of existing mathematical models of the soil cutting process with experimental data, and this allowed the essential features of a more complex model that should give improved predictions to be determined.

TL;DR: In this article, the effect of moisture content, threshing speed and length of storage period on the performance and quality of two varieties of soybeans was investigated, and it was found that unthreshed grain increased with an increase in pod moisture content whereas grain damage decreased with an increasing in grain moisture content.

TL;DR: In this article, a non-linear least squares regression program was used to fit 6 mathematical models developed by other researchers to the experimental data and the minimum standard error of estimate (1·5%) of equilibrium moisture content was obtained by using the Henderson-Thompson model.

TL;DR: In this paper, a simple geometrical theory is presented for pneumatic tyre deflection under load on a smooth, rigid, plane surface, in terms of dimensionless parameters, in a dimensional, empirical form suitable for fitting to experimental data relating load, inflation pressure, and deflection; and relating maximum permissible load to inflation pressure and tyre geometry.

TL;DR: In this paper, the authors measured the charge level attained by the spray produced with an induction charging, pneumatic atomizing nozzle at liquid flow rates relevant to cereal spraying from a tractor-mounted machine.

TL;DR: In this article, the relative contributions of macro-structural components of the corn cob to its apparent elastic modulus, crushing strength and modulus of toughness were evaluated, and effects of corn variety, harvesting date, level of fertilizer application and soil type on cob mechanical properties were investigated.

TL;DR: In this paper, the damage of seeds in grain augers was divided into shearing and jamming, occurring at the inlet and the casing wall, respectively, and measures for the reduction of jamming were summarized.

TL;DR: In this paper, a small chamber for studying the reaction of plants to radiation frost is described, which incorporates a radiation sink that comprises a blackened, refrigerated brass surface, and walls whose temperature can be controlled for convective exchange.

TL;DR: In this article, the authors present a 2-stage, measured parameter, infiltration model, which has been verified against finite difference solutions of the unsaturated flow equation, by laboratory tests and has been evaluated under field conditions.

TL;DR: In this article, a method of predicting the moisture content of standing grain using weather records is developed, based on equations developed from previous thin layer drying experiments and uses values of the parameters calculated directly from these experiments and not, as in previous models, from the best fit of the equations to field results.