Home About us Contact | |||
Inclined Plane (inclined + plane)
Selected AbstractsResponse of a double-wedge base-isolation deviceEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 13 2004J. Enrique Luco Abstract A novel base-isolation device is described and its performance is compared with that of a friction pendulum bearing. In its simplest form, the device consists of two wedges sliding on a horizontal plane in opposite directions and constrained from retreating by ratchets or bilinear dampers. The superstructure rests at the intersection of the two wedges. For a sufficiently large horizontal acceleration of the base, the structure starts to move up the inclined plane of one of the wedges, which remains fixed while the second wedge is slaved to follow the structure. As the direction of the base acceleration reverses, the process is reversed and the structure starts to climb on the second inclined plane while the first wedge follows. The overall result is that the horizontal acceleration of the structure is reduced with respect to that of the base and that kinetic energy associated with horizontal velocities is systematically transformed into potential energy. In the case of motion in a vertical plane, the device has the following advantages over a friction pendulum: (i) the sliding surface is linear instead of curved, (ii) kinetic energy is systematically transformed into potential energy during the strong ground motion, and (iii) the device is slowly self-centering. Copyright © 2004 John Wiley & Sons, Ltd. [source] A numerical study of wave structures developed on the free surface of a film flowing on inclined planes and subjected to surface shearINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 7 2006N. H. Shuaib Abstract In this work, we determine the different patterns of possible wave structures that can be observed on a thin film flowing on an inclined plane when at the free surface a shear force (surface traction) is applied. Different wave structures are obtained dependening on the selected combination of downstream and upstream boundary conditions and initial conditions. The resulting initial boundary value problems are solved numerically using the direct BEM numerical solution of the complete two-dimensional Stokes system of equations. In our numerical results, the initial discontinuous shock profiles joining uniform fluid depths are smoothed due to the two-dimensional character of the Stokes formulation, including the effect of the gravitational force as well as the interfacial surface tension force. In this way, physically feasible continuous surface profiles are determined, in which the initial uniform depths are joined by smooth moving wave structures. Numerical solutions have been attained to reproduce the different patterns of possible wave structures previously reported in the literature and extended to identify some other new structures and features defining the behaviour of the surface patterns. Copyright © 2006 John Wiley & Sons, Ltd. [source] APPLICATION OF COEFFICIENT OF FRICTION TO THE SEPARATION OF COCOA HUSK,BEANS MIXTUREJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2007O.K. OWOLARAFE ABSTRACT Investigation was carried out on the application of coefficient of friction in the separation of cocoa beans,husk mixture. An inclined plane at angles 20, 25 and 35°rotating at different speeds (215, 250 and 260 rpm) and receiving the mixture at heights 30, 60 and 90 mm, was used for the study. The result indicates that within the range of factors considered, the separation efficiency of the beans from the mixture increases with increase in speed of rotation and height of fall, while it decreases with increase in angle of inclination. Statistical analysis shows that the effects of each of the factors and that of their interaction are significant at 99%. The best separation efficiency (99%) was observed at a speed of 250 rpm, an angle of inclination of 25° and a height fall of 90 mm. PRACTICAL APPLICATIONS Separation of cocoa beans from the husks has been a serious problem in cocoa processing. Handpicking is still being used to separate the mixture of cocoa beans,husk even with the mechanical pod breaker available. This therefore constitutes a tedious operation. An inclined plane mechanism tested for the separation of the mixture in this study can be incorporated into the design of the cocoa pod processor to reduce the drudgery involved in cocoa processing and improve the quality of the product. [source] Bumble bee preference for flowers arranged on a horizontal plane versus inclined planesFUNCTIONAL ECOLOGY, Issue 6 2008T. T. Makino Summary 1Determining factors affecting pollinator visitation is the key to understanding the reproductive success of animal-pollinated plants. The inclination of the ground where plants grow, which has been little studied, could be one such factor. There may be differences in foraging performance when visiting flowers on horizontal planes compared with flowers on inclines planes. And if this is the case, pollinators may have a preference for horizontal or inclined planes. To test these possibilities, a series of laboratory experiments with bumble bees and arrays of artificial flowers were conducted. 2In the first experiment, bees were presented with a pair of floral arrays, one on a horizontal plane and one sloping. The bees preferred visiting flowers on the horizontal array. 3In the second experiment, bees were allowed to forage on a flower array tilted at various angles ranging from 0° (horizontal) to 90° (vertical). It was found that their foraging performance decreased with increasing angles, showing a 9·1% reduction from 0° to 90° arrays. This reduction was caused by an increased travel time between flowers, when moving upslope or downslope. 4These results suggest that plants growing on steep slopes may be less preferred by pollinators. Future studies are needed to clarify how slopes affect pollinator behaviour in field conditions and the ecological influences on plant reproduction. [source] A numerical study of wave structures developed on the free surface of a film flowing on inclined planes and subjected to surface shearINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 7 2006N. H. Shuaib Abstract In this work, we determine the different patterns of possible wave structures that can be observed on a thin film flowing on an inclined plane when at the free surface a shear force (surface traction) is applied. Different wave structures are obtained dependening on the selected combination of downstream and upstream boundary conditions and initial conditions. The resulting initial boundary value problems are solved numerically using the direct BEM numerical solution of the complete two-dimensional Stokes system of equations. In our numerical results, the initial discontinuous shock profiles joining uniform fluid depths are smoothed due to the two-dimensional character of the Stokes formulation, including the effect of the gravitational force as well as the interfacial surface tension force. In this way, physically feasible continuous surface profiles are determined, in which the initial uniform depths are joined by smooth moving wave structures. Numerical solutions have been attained to reproduce the different patterns of possible wave structures previously reported in the literature and extended to identify some other new structures and features defining the behaviour of the surface patterns. Copyright © 2006 John Wiley & Sons, Ltd. [source] Development of a biologically inspired locomotion system for a capsule endoscopeTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 4 2009Daisuke Hosokawa Abstract Background A capsule endoscope has a limited ability to obtain images of the digestive organs because its movement depends on peristaltic motion. To overcome this problem, capsule endoscopes require a propulsion system. Methods This paper proposes a propulsion system for a capsule endoscope that mimics the locomotive mechanism of snails and earthworms. The prototype crawler can elongate and contract itself longitudinally and adhere to a wall via suction cups. Results We investigated the effect of the inclination angle of the propulsion plane, the mucus viscosity between the propulsion plane and the crawler, and the stiffness of the propulsion plane on the locomotion of the prototype crawler. We found that the crawler could move on a rubber sheet and on inclined planes covered with mucus. We discussed advantages and limitations of the prototype crawler compared to the different locomotive systems developed in former studies. Conclusions We believe that the prototype crawler provides a better understanding of the propulsion mechanism for use in the gastrointestinal tract. Copyright © 2009 John Wiley & Sons, Ltd. [source] |