Ellipsograph for pantograph Patent

Ellipsograph for describing and cutting ellipses with minimal axial dimension

Evaluation of a series hybrid thrust bearing at DN values to three million. 2: Fabrication and testing

Results of tests made to determine the experimental performance of a series hybrid bearing are reported. The bearing consists of a 150 mm ball bearing and a centrifugally actuated, conical, fluid film bearing fitting an envelope with an outer radius of 86.4 mm (3.4 in.) and inner radius of 71 mm (2.8 in.). Tests were conducted up to 16,500 rpm, at which speed an axial load of 15,568 N (3500 lb) was safely supported by the hybrid bearing system. Through the employment of the series hybrid bearing principle, it was possible to reduce the effective ball bearing speed to approximately one-half of the shaft speed. A reduction of this magnitude should result in a tenfold increase in the ball bearing fatigue life. A successful simulation of fluid film bearing lubricant supply failure, performed repeatedly at an operating speed of 10,000 rpm, resulted in complete and smooth change over to full scale ball bearing operation when the oil supply to the fluid film bearing was discontinued. Reactivation of the fluid film supply system produced a flawless return to the original mode of hybrid operation

Cyber Buddy is Better than No Buddy: A Test of the Köhler Motivation Effect in Exergames.

Objective: Although exergames are popular, few people take advantage of the potential of group dynamics to motivate play (and achieve associated health bene?ts). One motivation gain phenomenon has shown promise for motivating greater effort in partnered exergames: The Koehler effect (working at a task with a more capable partner where one’s performance is indispensable to the group). This article examines whether a Koehler effect can be demonstrated in an exergame by exercising with a moderately superior humanoid, software-generated partner. Materials and Methods: Male and female (n = 120; mean age, 19.41 years) college students completed a series of plank exercises using ‘‘CyBuddy Exercise,’’ a program developed speci?cally for this study. In a lab in an academic building, participants completed the exercises individually and, after a rest, were randomly assigned to complete the same exercises again, but with a ‘‘live’’ human partner (HP) presented virtually, a nearlyhuman-like, humanoid partner (NHP), a hardly human-like, software-generated partner (HHP), or a no-partner control condition (IC), with equal numbers in each group (i.e., n = 30). Exercise persistence, perceived exertion, self-ef?cacy beliefs, enjoyment, and intentions to exercise were recorded and analyzed. Results: A 4X2 analysis of variance on the (Block 2 – Block 1) difference scores showed that a signi?cant Koehler motivation gain was observed in all partner conditions (compared with IC), but persistence was signi?cantly greater with HPs than with either NHP or HHP humanoid partners (P < 0.05). By the conclusion of the study, there were no signi?cant differences among the partnered conditions in perceived exertion, self-ef?cacy, enjoyment, or future intentions to exercise. Conclusions: These results suggest that a software-generated partner can elicit the Koehler motivation gain in exergames, but not as strongly as a partner who is thought to be human

Evaluation of a series hybird thrust bearing at DN values to three million. 1: Analysis and design

The analysis and design are presented of a hybrid bearing consisting of a 150-mm ball bearing and a centrifugally actuated, conical, fluid film bearing fitting an envelope with an outer radius of 86.4 mm (3.4 in.) and an inner radius of 71 mm (2.8 in.). The bearing analysis, combined with available torque data on ball bearings, indicates that an effective speed split between the ball and fluid-film bearings of 50 percent may be expected during operation at 20,000 rpm and under an axial load of 17,800 newtons (4000 lbs.). This speed split can result in a ten-fold increase in the life of the ball bearing when compared to a simple ball bearing system operating under similar conditions

Design and evaluation of a 3 million DN series-hybrid thrust bearing

The bearing, consisting of a 150-mm ball bearing and a centrifugally actuated, conical, fluid-film bearing, was fatigue tested. Test conditions were representative of a mainshaft ball bearing in a gas turbine engine operating at maximum thrust load to simulate aircraft takeoff conditions. Tests were conducted up to 16000 rpm and at this speed an axial load of 15568 newtons (3500 lb) was safely supported by the hybrid bearing system. Through the series-hybrid bearing principle, the effective ball bearing speed was reduced to approximately one-half of the shaft speed. It was concluded that a speed reduction of this magnitude results in a ten-fold increase in the ball bearing fatigue life. A successful evaluation of fluid-film bearing lubricant supply failure was performed repeatedly at an operating speed of 10,000 rpm. A complete and smooth changeover to full-scale ball bearing operation was effected when the oil supply to the fluid-film bearing was cut off. Reactivation of the fluid-film oil supply system resulted in a flawless return to the original mode of hybrid operation

AFRICAN AMERICAN GIRLS AND PHYSICAL AGGRESSION: A RESILIENCE STUDY ON HOW ADULT AFRICAN AMERICAN WOMEN OVERCAME PHYSICALLY AGGRESSIVE BEHAVIOR POST ADOLESCENCE

Adolescent African American girls who use physical aggression to resolve conflict are perceived to be a menace to society. Because adolescence is a developmental stage in the life cycle, society should understand that for many girls fighting is nothing more than a phase that these girls may eventually outgrow. Much like other adolescent youth, some African American girls who display physically aggressive behaviors can graduate from high school, go on to college and lead successful lives. This qualitative study focused on the resilience of African American girls who used physical violence in adolescence but later made a conscious decision to resolve conflict non-violently. In depth interviews were conducted with 10 college-educated African American women ages 24-46 that used physical violence to resolve conflict as an adolescent but as an adult learned alternate strategies. Findings included themes of age of first fight; how the girls learn to fight; the realization that fighting became an option for resolving conflict; was fighting enjoyable; were they bullied or harassed prior to fight; how family resolved conflict; how were disputes resolved within their community; source of fights in high school; the decision to go to college; how conflict was resolved in college; resolving conflict after college; the decision to change; reflections on the need to use physical violence as an African American woman. Findings suggest that in late adolescence or early adulthood the women come to the realization that the consequences for using physically aggressive behaviors are too great and that they have to find a more positive way of resolving conflict. Implications for clinical practice and future research are also discussed

Grandma\u27s pitcher: A Series

None provided

Small, high-speed bearing technology for cryogenic turbo-pumps

The design of 20-mm bore ball bearings is described for cryogenic turbo-machinery applications, operating up to speeds of 120,000 rpm. A special section is included on the design of hybrid bearings. Each hybrid bearing is composed of a ball bearing in series with a conventional pressurized fluid-film journal bearing. Full details are presented on the design of a test vehicle which possesses the capability of testing the above named bearings within the given speed range under externally applied radial and axial loads