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A. E. Stainsby

Bio: A. E. Stainsby is an academic researcher. The author has contributed to research in topics: Loam & Agriculture. The author has an hindex of 1, co-authored 1 publications receiving 75 citations.

Papers
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Journal ArticleDOI
01 Jun 1962
TL;DR: The theory of the operation of porous metal bearings as given in the 1957 Conference on Lubrication and Wear has now been extended as discussed by the authors, leading to a critical value for a 360° porous bearing.
Abstract: The theory of the operation of porous metal bearings as given in the 1957 Conference on Lubrication and Wear has now been extended. The analysis of a 360° porous bearing leads to a critical value o...

80 citations

Journal ArticleDOI
TL;DR: In this article , the authors evaluated the effect of CA, as practiced by farmers, and compared farmer descriptions of soil health with scientific measures, and concluded that CA practices improved qualitative soil characteristics as sensed by farmers and this positive response was consistent across most fields.
Abstract: Abstract The challenges of soil degradation and low crop yield are being addressed in East Africa using a number of soil health-promoting farming systems including Conservation Agriculture (CA). CA is based on principles of minimal soil disturbance, continuous soil cover, and crop diversity, though implementation on farms may vary due to local circumstances. This study evaluated the effect of CA, as practiced by farmers, and compared farmer descriptions of soil health with scientific measures. CA and non-CA fields were compared in regions of Ethiopia (23 farms), Kenya (23 farms), and Tanzania (13 farms) with most fields repeatedly sampled for 2 to 3 years. CA and non-CA fields were located within meters, on soils with the same texture, growing similar crops. CA systems used precision planting, mostly with basins. Soil parameters were assessed using a participatory approach where farmers and field technicians collected data. CA practices improved qualitative soil characteristics as sensed by farmers (e.g., hoe-ability, crusting, smell, water infiltration), and this positive response was consistent across most fields. For qualitative data, the logarithm of the odds ratio estimates method was used to test the probability that CA would provide soil improvement. Fields under the CA treatment had a higher probability of rating better than non-CA fields. Quantitative measurements of pH and microbial respiration validated farmer assessments. CA-managed soils were weakly associated with darker colour, indicating higher soil organic matter. Sandy soils did not appear to improve with CA as dramatically as clay and loam soils, suggesting different CA strategies may be required. We discuss both benefits and drawbacks of this type of participatory, on-farm research. We conclude that farmer participation as citizen scientists will advance soil restoration in East Africa and increase the potential for farmer-to-farmer knowledge exchange of soil-improving practices.

Cited by
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TL;DR: In this article, the Darcy-Brinkman equation is used to model the flow and heat transfer in a horizontal composite porous medium, where the viscous and Darcian dissipation terms are also included in the energy equation.
Abstract: The problem of unsteady oscillatory flow and heat transfer in a horizontal composite porous medium is performed. The flow is modeled usi ng the Darcy-Brinkman equation. The viscous and Darcian dissipation terms are also included in the energy equation. The partial differential equations governing th e flow and heat transfer are solved analytically using two-term harmonic and non-harmonic functions in both regions of the channel. Effect of the physical parameters such as the porous medium parameter, ratio of viscosity, oscillation amplitude, conductivity r atio, Prandtl number and the Eckert number on the velocity and/or temperature fields are shown gr aphically. It is observed that both the velocity and temperature fields in the channel d ecrease as either of the porous medium parameter or the viscosity ratio increases while they increase with increases in the oscillation amplitude. Also, increasing the thermal co nductivity ratio is found to suppress the temperature in both regions of the channel. The effects of the Prandtl and Eckert numbers are found to decrease the thermal state in the channel as well.

72 citations

Journal ArticleDOI
TL;DR: In this paper, a numerical solution for the hydrodynamic lubrication of finite porous journal bearings considering the flexibility of the liner is introduced, and the Brinkman-extended Darcy equations and the Stokes' equations are utilized to model the flow in the porous region and fluid film region, respectively.

42 citations

Journal ArticleDOI
TL;DR: In this article, the unique features which are introduced into the theory of hydrodynamic lubrication of bearings when the bearings are permeable and tolerate a flow of oil are discussed.
Abstract: In this report, we discuss the unique features which are introduced into the theory of hydrodynamic lubrication of bearings when the bearings are permeable and tolerate a flow of oil. The subject of the analysis is not entirely new, and a few aspects of the problem have been treated by several authors [1, 2, 4, 5, 9].

38 citations

Journal ArticleDOI
TL;DR: In this article, a numerical simulation is presented for the thermo-hydrodynamic self-lubrication aspect analysis of porous circular journal bearing of finite length with sealed ends, which consists in analyzing the thermal effects on the behavior of circular porous journal bearings.

34 citations

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TL;DR: Theoretical study of porous slider bearing with couple stress fluid as lubricant is made and the lubrication qualities of couple stress fluids are examined in this article, where analytical expressions for load capacity, frictional force and the centre of pressure are derived.
Abstract: Theoretical study of porous slider bearing with couple stress fluid as lubricant is made and the lubrication qualities of couple stress fluid are examined. The lower surface is covered by a thin porous material and the upper one, having arbitrary shape, moves in its own plane with constant velocity. Analytical expressions for load capacity, frictional force and the centre of pressure are derived. It yields increase in, load capacity and ensures the decrease in coefficient of friction. The problem is also discussed in the context of various geometries viz, (1) Rayleigh step bearings and (2) inclined slider bearings. Bounds on flow rate, frictional coefficient, centre of pressure and time-height relation are obtained and compared with classical case, Gross [1]. Suitable design parameters are predicted for the efficient lubrication of slider bearings.

28 citations