1,015 research outputs found
Comparison of several methods for predicting separation in a compressible turbulent boundary layer
Several methods for predicting the separation point for a compressible turbulent boundary layer were applied to the flow over a bump on a wind-tunnel wall. Measured pressure distributions were used as input. Two integral boundary-layer methods, three finite-difference boundary-layer methods, and three simple methods were applied at five free-stream Mach numbers ranging from 0.354 to 0.7325. Each of the boundary-layer methods failed to explicitly predict separation. However, by relaxing the theoretical separation criteria, several boundary-layer methods were made to yield reasonable separation predictions, but none of the methods accurately predicted the important boundary-layer parameters at separation. Only one of the simple methods consistently predicted separation with reasonable accuracy in a manner consistent with the theory. The other methods either indicated several possible separation locations or only sometimes predicted separation
Frictional coupling between sliding and spinning motion
We show that the friction force and torque, acting at a dry contact of two
objects moving and rotating relative to each other, are inherently coupled. As
a simple test system, a sliding and spinning disk on a horizontal flat surface
is considered. We calculate, and also measure, how the disk is slowing down,
and find that it always stops its sliding and spinning motion at the same
moment. We discuss the impact of this coupling between friction force and
torque on the physics of granular materials.Comment: 4 pages, 5 figures; submitte
Appreciative Inquiry as Organizational Change in a Community Mental Health Setting
poster abstractAppreciative Inquiry (AI) is an approach to organizational change that focuses on the strengths of an organization – discovering what is working well, and generating ideas within the organization for building on those strengths. AI has been applied in a variety of contexts including education, social work, health care, and academia. Little to no research, however, has applied AI to mental health contexts. The current study reports themes from staff member interviews conducted in the early phases of AI applied in a community mental health center (CMHC); these themes paint a picture of this CMHC “at its best” and will be fed-back to employees to lay the foundation for change and enhancing morale among staff. Interviews were conducted by 11 staff who volunteered from various departments and were trained by research staff at an all-day training. Appreciative Interviews first involved asking staff to describe a time they were at their best at this organization. Next, participants were asked to share what it was about themselves, others, and the setting that contributed to this experience. Additionally, interviewees were asked to “dream into the future” and to describe what they wish to see for this organization. Interviews were audio recorded, transcribed, and de-identified. Iterative, consensus-based coding was conducted by a multidisciplinary team that included CMHC staff. Several consistent themes emerged among participants’ stories. Staff at their best frequently reported feeling effective and seeing success in working with consumers. Other themes included working as a team, communicating well, and trusting one another. Stories also involved feeling valued and supported by their supervisors and coworkers. A foundational aspect involved believing in and caring about consumers with whom they work. Themes from participants’ interviews reflect perceptions of this community mental health center at its best and are consistent with tenets self-determination theory and future study
Comparison of Positive and Negative Verbal Cueing on Muscular Endurance in College - Aged Females
poste
Centennial-scale reductions in nitrogen availability in temperate forests of the United States
Forests cover 30% of the terrestrial Earth surface and are a major component of the global carbon
(C) cycle. Humans have doubled the amount of global reactive nitrogen (N), increasing deposition of N onto forests worldwide. However, other global changes—especially climate change and elevated atmospheric carbon dioxide concentrations—are increasing demand for N, the element limiting primary productivity in temperate forests, which could be reducing N availability. To determine the long-term, integrated effects of global changes on forest N cycling, we measured stable N isotopes in wood, a proxy for N supply relative to demand, on large spatial and temporal scales across the continental U.S.A. Here, we show that forest N availability has generally declined across much of the U.S. since at least 1850 C.E. with cool, wet forests demonstrating the greatest declines. Across sites, recent trajectories of N availability were independent of recent atmospheric N deposition rates, implying a minor role for modern N deposition on the trajectory of N status of North American forests. Our results demonstrate that current trends of global changes are likely to be consistent with forest oligotrophication into theforeseeable future, further constraining forest C fixation and potentially storage
Human Resources and the Resource Based View of the Firm
The resource-based view (RBV) of the firm has influenced the field of strategic human resource management (SHRM) in a number of ways. This paper explores the impact of the RBV on the theoretical and empirical development of SHRM. It explores how the fields of strategy and SHRM are beginning to converge around a number of issues, and proposes a number of implications of this convergence
The compositional and evolutionary logic of metabolism
Metabolism displays striking and robust regularities in the forms of
modularity and hierarchy, whose composition may be compactly described. This
renders metabolic architecture comprehensible as a system, and suggests the
order in which layers of that system emerged. Metabolism also serves as the
foundation in other hierarchies, at least up to cellular integration including
bioenergetics and molecular replication, and trophic ecology. The
recapitulation of patterns first seen in metabolism, in these higher levels,
suggests metabolism as a source of causation or constraint on many forms of
organization in the biosphere.
We identify as modules widely reused subsets of chemicals, reactions, or
functions, each with a conserved internal structure. At the small molecule
substrate level, module boundaries are generally associated with the most
complex reaction mechanisms and the most conserved enzymes. Cofactors form a
structurally and functionally distinctive control layer over the small-molecule
substrate. Complex cofactors are often used at module boundaries of the
substrate level, while simpler ones participate in widely used reactions.
Cofactor functions thus act as "keys" that incorporate classes of organic
reactions within biochemistry.
The same modules that organize the compositional diversity of metabolism are
argued to have governed long-term evolution. Early evolution of core
metabolism, especially carbon-fixation, appears to have required few
innovations among a small number of conserved modules, to produce adaptations
to simple biogeochemical changes of environment. We demonstrate these features
of metabolism at several levels of hierarchy, beginning with the small-molecule
substrate and network architecture, continuing with cofactors and key conserved
reactions, and culminating in the aggregation of multiple diverse physical and
biochemical processes in cells.Comment: 56 pages, 28 figure
Signaling in Secret: Pay-for-Performance and the Incentive and Sorting Effects of Pay Secrecy
Key Findings: Pay secrecy adversely impacts individual task performance because it weakens the perception that an increase in performance will be accompanied by increase in pay; Pay secrecy is associated with a decrease in employee performance and retention in pay-for-performance systems, which measure performance using relative (i.e., peer-ranked) criteria rather than an absolute scale (see Figure 2 on page 5); High performing employees tend to be most sensitive to negative pay-for- performance perceptions; There are many signals embedded within HR policies and practices, which can influence employees’ perception of workplace uncertainty/inequity and impact their performance and turnover intentions; and When pay transparency is impractical, organizations may benefit from introducing partial pay openness to mitigate these effects on employee performance and retention
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