To “Sketch-a-Scratch”

A surface can be harsh and raspy, or smooth and silky, and everything in between. We are used to sense these features with our fingertips as well as with our eyes and ears: the exploration of a surface is a multisensory experience. Tools, too, are often employed in the interaction with surfaces, since they augment our manipulation capabilities. “Sketch-a-Scratch” is a tool for the multisensory exploration and sketching of surface textures. The user’s actions drive a physical sound model of real materials’ response to interactions such as scraping, rubbing or rolling. Moreover, different input signals can be converted into 2D visual surface profiles, thus enabling to experience them visually, aurally and haptically

Free vibration of a three-layered sandwich beam using the dynamic stiffness method and experiment

In this paper, an accurate dynamic stiffness model for a three-layered sandwich beam of unequal thicknesses is developed and subsequently used to investigate its free vibration characteristics. Each layer of the beam is idealised by the Timoshenko beam theory and the combined system is reduced to a tenth-order system using symbolic computation. An exact dynamic stiffness matrix is then developed by relating amplitudes of harmonically varying loads to those of the responses. The resulting dynamic stiffness matrix is used with particular reference to the Wittrick-Williams algorithm to carry out the free vibration analysis of a few illustrative examples. The accuracy of the theory is confirmed both by published literature and by experiment. The paper closes with some concluding remarks. (c) 2007 Elsevier Ltd. All rights reserved

Design and development of a new approach to wrist rehabilitation

Wrist injuries are a very common type of pathology that can compromise most daily tasks. Conventional therapy is dependent on the availability of physiotherapists as well as devices designed for this purpose. Conventional devices do not accompany the patient throughout their rehabilitation process, requiring their constant replacement. Vibratory therapies emerged in recent years and have demonstrated several benefits in this area. However, there are few vibratory devices designed for wrist rehabilitation. In this paper, we propose two different portable and active models for wrist rehabilitation based on vibratory therapy for wrist rehabilitation. The first model has a cylindrical shape and the second model has a dumbbell shape. The results obtained showed that vibratory therapy can assist the wrist rehabilitation because it promoted improvements in joint amplitude gain in all wrist movements. Furthermore, the second device demonstrated higher joint gains than the first device. In addition, the results obtained from the measurement of accelerations demonstrate that the natural frequencies of both devices are adequate for wrist and forearm rehabilitation as well as the mode of vibration. There are differences between what the simulations predicted and what was obtained in practice in terms of natural frequency values.- (undefined

Aerospace medicine and biology. A continuing bibliography with indexes, supplement 195

This bibliography lists 148 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1979

Mutual positioning of the being assembled cylindrical parts under controlled dry friction

Applied for automated assembly the displacement of the part under controlled dry friction is analyzed. The paper deals with vibrational non - impact displacement of a mobile - based body when the body is subjected to kinematical excitement. Based on a simplified dynamic model of vibratory displacement under controlled dry friction the areas of the system and excitation parameters sets exist with different motion regimes and when controlling dry friction at particular time intervals. There were formed dependencies of vibratory displacement from dynamic system and excitation parameters. Based on performed part–to–part positioning analysis were designed schemas of vibratory assembly devices under controlled of the dry friction those may be used for joining of the cylindrical part

Conceptual design and analysis of roads and road construction machinery for initial lunar base operations

Recent developments have made it possible for scientists and engineers to consider returning to the Moon to build a manned lunar base. The base can be used to conduct scientific research, develop new space technology, and utilize the natural resources of the Moon. Areas of the base will be separated, connected by a system of roads that reduce the power requirements of vehicles traveling on them. Feasible road types for the lunar surface were analyzed and a road construction system was designed for initial lunar base operations. A model was also constructed to show the system configuration and key operating features. The alternate designs for the lunar road construction system were developed in four stages: analyze and select a road type; determine operations and machinery needed to produce the road; develop machinery configurations; and develop alternates for several machine components. A compacted lunar soil road was selected for initial lunar base operations. The only machinery required to produce this road were a grader and a compactor. The road construction system consists of a main drive unit which is used for propulsion, a detachable grader assembly, and a towed compactor