Heuristic explanation of journal bearing instability

A fluid-filled journal bearing is viewed as a powerful pump circulating fluid around the annular space between the journal and the bearing. A small whirling motion of the journal generates a wave of thickness variation progressing around the channel. The hypothesis that the fluid flow drives the whirl whenever the mean of the pumped fluid velocity is greater than the peripheral speed of the thickness variation wave is discussed and compared with other simple explanations of journal bearing instability. It is shown that for non-cavitation long bearings the hypothesis predicts instability onset correctly for unloaded bearings but gradually overpredicts the onset speed as the load is increased

Physical explanations of the destabilizing effect of damping in rotating parts

The destabilizing effect of rotating damping was investigated. When the rotation was faster than the whirl, rotating damping drags the orbiting particle forward. When stationary damping was also present, the stability borderline was readily determined by balancing the backward and forward drags. A key notion was that a forward whirl at rate omega a sub n with respect to stationary axes appears to be a backward whirl at rate Omega - omega sub n with respect to a system rotating supercritically at rate Omega. The growth rate of unstable whirls (or the decay rate of stable whirls was readily estimated by a simple energy balance

ON SCALING LAWS FOR MATERIAL DAMPING

Scaling laws for dampin

Magmatic Intrusions into the Sulfur-Rich Carmel Formation on the Colorado Plateau, USA: Implications for the Mars 2020 Mission

We report on basaltic dikes in the Colorado Plateau, which crosscut sulfate bearing sediments and compare this to Martian basalts and basaltic sediments in contact with sulfate mineralizations

Design Principles Influencing Secondary School Counselors\u27 Satisfaction of a Decision-Support System

In the current era of accountability, secondary school counselors are expected to use data to drive program decision-making, identify and implement evidence-based interventions to create systemic change, and utilize emerging technology. Research shows it is difficult for school counselors to meet any of these expectations. A decision support system (DSS) is a technology that takes minimal effort to learn and can assist in decision-making processes. This design science research builds and evaluates an IT artifact, a decision-support system, in an attempt to solve the problems facing school counselors. To develop this system, four design principles (system usefulness, interface quality, information quality, and customization) were incorporated into the components of a DSS. A field study was then employed to test the DSS in multiple school counseling settings to determine if the IT artifact solved the identified problems, and also to measure the influence of the design principles on school counselors’ satisfaction of the system. Results indicated that 91.7% of school counselors agreed the system was in fact useful, indicating technology is capable of assisting school counselors in data-driven decision-making and identifying appropriate interventions for their program, as well as demonstrating the efficacy of design science research to solve problems. Furthermore, the SEM model used to evaluate the system showed that while all design principles were positive, interface quality had the most considerable influence on users’ satisfaction. This finding indicates the importance of using consistent interface design in the development of future technologies for non-technical fields. The research concludes with an updated model for decision-making in school counseling that incorporates technology in all phases of the process

Authentic Leadership\u27s Ethical Influence on Retail Telecom Performance Management Systems

This qualitative study of retail telecommunication salespeople and their employers supported the existing literature about authentic leadership’s positive influence on organizational citizenship behavior, affective commitment, ethical climate, and employee motivation in balancing performance management systems. Through salesperson self-regulation, this study also supported goal setting and other task-based motivation theories. The study added to the paucity of research on the relationship of pressure to unethical behavior and found the time dimension of goals was less important than threatening pressure. Both ethical codes and personal values were found to motivate ethical behavior more than either one by itself. Also, the study found the store manager relationship was critical to salesperson motivation and performance which should be studied further, especially when dysfunctional, adding to leader membership exchange (LMX) constructs. Finally, more telecom salespeople were motivated relationally than financially, and their emotional depletion was more related to negative interpersonal interactions than task-based effort as reflected in expectancy-value theory. This requires further study. The study incorporated a philosophical assumption of a Biblical worldview

Torn posterior capsule: prevention, recognition and management

Journal ArticleModern cataract surgery performed with phacoemulsification allows meticulous intraocular control and minimal incision size, but has the inherent risk of capsular rupture. Therefore, surgeons performing cataract surgery will inevitably face the complication of a torn posterior capsule. Torn posterior capsules are reported to occur in 0.3%-6% of cases. Faced with this complication, it is best for a surgeon to approach its management with the same systematic analytical and objective evaluation that would be applied to any surgery. Keep in mind that "great opportunity is usually disguised as an unsolvable problem." Proper resolution will then provide the patient with the best surgical, and therefore the best visual, outcome

Regulating Highly Automated Robot Ecologies: Insights from Three User Studies

Highly automated robot ecologies (HARE), or societies of independent autonomous robots or agents, are rapidly becoming an important part of much of the world's critical infrastructure. As with human societies, regulation, wherein a governing body designs rules and processes for the society, plays an important role in ensuring that HARE meet societal objectives. However, to date, a careful study of interactions between a regulator and HARE is lacking. In this paper, we report on three user studies which give insights into how to design systems that allow people, acting as the regulatory authority, to effectively interact with HARE. As in the study of political systems in which governments regulate human societies, our studies analyze how interactions between HARE and regulators are impacted by regulatory power and individual (robot or agent) autonomy. Our results show that regulator power, decision support, and adaptive autonomy can each diminish the social welfare of HARE, and hint at how these seemingly desirable mechanisms can be designed so that they become part of successful HARE.Comment: 10 pages, 7 figures, to appear in the 5th International Conference on Human Agent Interaction (HAI-2017), Bielefeld, German