Reply to the comment by Jacobs and Thorpe

Reply to a comment on "Infinite-Cluster geometry in central-force networks", PRL 78 (1997), 1480. A discussion about the order of the rigidity percolation transition.Comment: 1 page revTe

A Monte Carlo Method for Modeling Thermal Damping: Beyond the Brownian-Motion Master Equation

The "standard" Brownian motion master equation, used to describe thermal damping, is not completely positive, and does not admit a Monte Carlo method, important in numerical simulations. To eliminate both these problems one must add a term that generates additional position diffusion. He we show that one can obtain a completely positive simple quantum Brownian motion, efficiently solvable, without any extra diffusion. This is achieved by using a stochastic Schroedinger equation (SSE), closely analogous to Langevin's equation, that has no equivalent Markovian master equation. Considering a specific example, we show that this SSE is sensitive to nonlinearities in situations in which the master equation is not, and may therefore be a better model of damping for nonlinear systems.Comment: 6 pages, revtex4. v2: numerical results for a nonlinear syste

How Farmers Bid Into the Conservation Reserve Program: An Empirical Analysis of CRP Offers Data

Replaced with revised version of paper 07/19/11.Land Economics/Use,

Antarctic Ocean polynyas

The spatial and temporal variability of sea ice concentrations derived from Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) brightness temperatures are presented. Emphasis is on the continental shelf region of the Ross Sea during 1984, when supporting data were obtained from oceanographic stations and moored instruments. The effects of the large spring polynya in the Ross Sea on summer insolation, surface heat layer storage, and late autumn ice formation are described

Effect of an alternate winglet on the pressure and spanwise load distributions of a first generation jet transport wing

Pressure and spanwise load distributions on a first-generation jet transport semispan model at subsonic speeds are presented. The wind tunnel data were measured for the wing with and without an alternate winglet. The results show that the winglet affected outboard wing pressure distributions and increased the spanwise loads near the tip

Description and simulation of an integrated power and attitude control system concept for space-vehicle application

An Integrated Power and Attitude Control System (IPACS) concept with potential application to a broad class of space missions is discussed. A description is given of the basic concept of combining the onboard energy storage and attitude control functions by storing energy in spinning flywheels which are used to provide control torques. A shuttle-launched Research and Applications Module (RAM) A303B solar-observatory mission having stringent pointing requirements (1.0 arc second) is selected to investigate possible interactions between energy storage and attitude control. A simulation of this spacecraft involving actual laboratory-model control-system hardware is presented. Simulation results are discussed which indicate that the IPACS concept, even in a failure-mode configuration, can readily meet the RAM A303B pointing requirements

Effect of winglets on a first-generation jet transport wing. 1: Longitudinal aerodynamic characteristics of a semispan model at subsonic speeds

The effects of winglets and a simple wing-tip extension on the aerodynamic forces and moments and the flow-field cross flow velocity vectors behind the wing tip of a first generation jet transport wing were investigated in the Langley 8-foot transonic pressure tunnel using a semi-span model. The test was conducted at Mach numbers of 0.30, 0.70, 0.75, 0.78, and 0.80. At a Mach number of 0.30, the configurations were tested with combinations of leading- and trailing-edge flaps

Effect of Winglets on a First-Generation Jet Transport Wing. 2: Pressure and Spanwise Load Distributions for a Semispan Model at High Subsonic Speeds

Pressure and spanwise load distributions on a first-generation jet transport semispan model at high subsonic speeds are presented for the basic wing and for configurations with an upper winglet only, upper and lower winglets, and a simple wing-tip extension. Selected data are discussed to show the general trends and effects of the various configurations

Making connections and promoting the profession: social media use by World Federation of Occupational Therapy member organisations

BACKGROUND: World Federation of Occupational Therapists (WFOT) member organisations comprise 77 national occupational therapy organisations across the world. Each national organisation interacts with its members and the public using diverse methods. Increasingly, national organisations are broadening their communication methods. OBJECTIVE: The objective of this study was to examine if and how occupational therapy organisations are using social media for communication, and if so, the types of concerns or barriers they experience and what role they anticipate social media might play in the near future. METHODS: An online survey was developed; 57 of 77 WFOT member organisations responded. FINDINGS: This study identified that WFOT national organisations are using social media, to varying degrees, with or without an individual formally assigned to manage social media. Respondents reported that they used social media to: communicate with members, promote the organisation and promote the profession. Commonly expressed needs included assistance with guide- lines for ethical social media use, developing technical expertise, and recognition of limits of time and competing priorities. Recommendations arising from this research are at the global, national, local and individual levels and incorporate active dissemination and pure diffusion approaches. Taking steps to increase the use of social media could indirectly impact occu- pational therapy practice through enhancing organisations’ abilities to support practitioners to enhance their practice. LIMITATIONS AND RECOMENDATIONS FOR FURTHER RESEARCH: Although 57% of WFOT member organisations returned usable responses, there may be some additional perspectives that were not captured. It would be helpful to contact non-responding organisations to explore their social media use and plans. Further research could examine how future initiatives put in place by WFOT impact social media use by member organisations.Published versio