1,690 research outputs found
Portrait of author Jackson A. Graves, [s.d.]
No full textPhotographic portrait of author Jackson A. Graves, [s.d.]. Graves is shown from his upper torso to his head and is looking to the right. He is wearing a light-colored suit, a light shirt, and a dark tie with a square pattern. He has light-colored hair that is neatly combed and parted at left, a thick light mustache, and light eyebrows. There are large bags beneath his eyes and his ears are very big
Simulation and Control of a Pneumatic Muscle Actuator for a Rehabilitation Robot
No full textThe perfomance of a pneumatic muscle actuator, invented by Jim Hennequin and used in a prototype wheelchair-mounted robot ann designed by the first author is reported. Experimental measurements were made of the output torque versus rotary motion and internal pressure. The torque available for a muscle of size 60 mm width by 90 mm length ranges from 1 to 15 Nm. The rotary stiffness of this muscle is 0.081 Nm/deg. A simulation model of the dynamic behaviour of the muscle attached to the robot arm using one-dimensional flow theory was written in ACSL (Advanced Continuous Simulation Language). The resultant simulation gives good agreement to within ± 5% of the experimental values. Control using proportional and a PID controller is shown to be effective
Finite Element Modeling of Microstructural Changes in Turning of AA7075-T651 Alloy and Validation
No full textThe surface characteristics of a machined product strongly influence its functional performance. During machining, the grain size of the surface is frequently modified, thus the properties of the machined surface are different to that of the original bulk material. These changes must be taken into account when modeling the surface integrity effects resulting from machining. In the present work, grain size changes induced during turning of AA 7075-T651 (160 HV) alloy are modeled using the Finite Element (FE) method and a user subroutine is implemented in the FE code to describe the microstructural change and to simulate the dynamic recrystallization, with the consequent formation of new grains. In particular, a procedure utilizing the Zener-Hollomon and Hall-Petch equations is implemented in the user subroutine to predict the evolution of the material grain size and the surface hardness when varying the cutting speeds (180 - 720 m/min) and tool nose radii (0.4 - 1.2 mm). All simulations were performed for dry cutting conditions using uncoated carbide tools. The effectiveness of the proposed FE model was demonstrated through its capability to predict grain size evolution and hardness modification from the bulk material to machined surface. The model is validated by comparing the predicted results with those experimentally observed
Painted portrait of Father Geronimo Boscana, O.F.M., author of Chinigchinich, [s.d.]
No full textPhotograph of a painted portrait of Father Geronimo Boscana, O.F.M., author of "Chinigchinich", [s.d.]. The friar is at center, is shown from his upper torso to his head and is looking slightly to the right. He is wearing a light-colored hooded robe with the hood pulled halfway up his head. He has some thin white hair but is mostly bald. Chinigchinich was an account of California Indian life, focused on the Indians near San Juan Capistrano
Portrait of James Laughlin, author of "This Is My Blood," [s.d.]
No full textPhotographic portrait of James Laughlin, author of "This Is My Blood," [s.d.]. A elderly man with smiling eyes turns his face toward the camera. He has a slight smile on his face, and a large nose, bushy eyebrows and slicked-back graying hair. He wears a light-colored suit, striped tie, and undergarment.; The book was to be published March 3, 1989 in a limited edition by The Yolla Bolly Press
Prediction of liver disease in patients whose liver function tests have been checked in primary care : model development and validation using population-based observational cohorts
No full textPublished by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.Peer reviewe
Fields of activity significance scientific college students [Campos de significación de la actividad científica en estudiantes universitarios]
No full textThis study has as purpose to show the beliefs, attitudes, knowledge and stereotypes of university students about scientific research. In order to reach it, the author carried out an exercise based on associative questions, individual and group interviews and a multiple choice questionnaire that was proposed to 273 students enrolled at two university centers at Guadalajara University (Universidad de Guadalajara). The information was then analyzed by means of the mixed content technique (open answers) and the statistic program SPSS (multiple choice questionnaire). The results show that most of the interview students have erroneous conceptions about the scientific duty and a very imprecise picture about the scientist and the domain and space in which he/she works. Since those social representations have been built throughout the student's academic life by several media (formal and informal), the author considers that it is essential to analyze them in order to increase the interest about scientific activity amongst the students
Fields of activity significance scientific college students [Campos de significación de la actividad científica en estudiantes universitarios]
No full textThis study has as purpose to show the beliefs, attitudes, knowledge and stereotypes of university students about scientific research. In order to reach it, the author carried out an exercise based on associative questions, individual and group interviews and a multiple choice questionnaire that was proposed to 273 students enrolled at two university centers at Guadalajara University (Universidad de Guadalajara). The information was then analyzed by means of the mixed content technique (open answers) and the statistic program SPSS (multiple choice questionnaire). The results show that most of the interview students have erroneous conceptions about the scientific duty and a very imprecise picture about the scientist and the domain and space in which he/she works. Since those social representations have been built throughout the student's academic life by several media (formal and informal), the author considers that it is essential to analyze them in order to increase the interest about scientific activity amongst the students
C.H. Dillon, S.D.
No full textTitle from unverified data provided by the Bain News Service on the negatives or caption cards.Forms part of: George Grantham Bain Collection (Library of Congress).General information about the Bain Collection is available at http://hdl.loc.gov/loc.pnp/pp.ggbai
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