Recent progress towards predicting aircraft ground handling performance

Capability implemented in simulating aircraft ground handling performance is reviewed and areas for further expansion and improvement are identified. Problems associated with providing necessary simulator input data for adequate modeling of aircraft tire/runway friction behavior are discussed and efforts to improve tire/runway friction definition, and simulator fidelity are described. Aircraft braking performance data obtained on several wet runway surfaces are compared to ground vehicle friction measurements. Research to improve methods of predicting tire friction performance are discussed

Can social prescribing provide the missing link?

Background: The voluntary sector has long been recognised as making an important contribution to individual and community health. In the UK, however, the links between primary health care services and the voluntary and community sector are often underdeveloped. Social prescribing is an innovative approach, which aims to promote the use of the voluntary sector within primary health care. Social prescribing involves the creation of referral pathways that allow primary health care patients with non-clinical needs to be directed to local voluntary services and community groups. Such schemes typically use community development workers with local knowledge who are linked to primary health care settings. Social prescribing therefore has the potential to assist individual patients presenting with social needs to access health resources and social support outside of the National Health Service. Aim: The aim of this paper is to explore the concept of social prescribing and discuss its value as a public health initiative embedded within general practice. Methods: The rationale for social prescribing and existing evidence are briefly reviewed. The paper draws on a case study of a pilot social prescribing scheme based in general practice. Data collected during the development, implementation and evaluation of the scheme are used to illustrate the opportunities and limitations for development in UK primary health care. Findings: The potential for social prescribing to provide a mediating mechanism between different sectors and address social need is discussed. The paper argues that social prescribing can successfully extend the boundaries of traditional general practice through bridging the gap between primary health care and the voluntary sector. The potential for wider health gain is critically examined. The paper concludes that social prescribing not only provides a means to alternative support but also acts as a mechanism to strengthen community–professional partnerships. More research is needed on the benefits to patients and professionals

Recent Progress Towards Predicting Aircraft Ground Handling Performance

The significant progress which has been achieved in development of aircraft ground handling simulation capability is reviewed and additional improvements in software modeling identified. The problem associated with providing necessary simulator input data for adequate modeling of aircraft tire/runway friction behavior is discussed and efforts to improve this complex model, and hence simulator fidelity, are described. Aircraft braking performance data obtained on several wet runway surfaces is compared to ground vehicle friction measurements and, by use of empirically derived methods, good agreement between actual and estimated aircraft braking friction from ground vehilce data is shown. The performance of a relatively new friction measuring device, the friction tester, showed great promise in providing data applicable to aircraft friction performance. Additional research efforts to improve methods of predicting tire friction performance are discussed including use of an instrumented tire test vehicle to expand the tire friction data bank and a study of surface texture measurement techniques

The linear polarization of lunar thermal emission at 3.1 mm wavelength

Several observations of the distribution of linearly polarized lunar thermal emission were made at a wavelength of 3.1 mm with 4.88 m parabolic reflector from February to March 1971. A shadow corrected rough surface thermal emission model was least squares fitted to the data. Results indicate an effective lunar dielectric constant of 1.34 + or -.08 with surface roughness characterized by a standard deviation of surface slopes of 18 deg + or - 2 deg. A comparison of these results with previously published values at other wavelengths suggests that the effective lunar dielectric constant decreases with decreasing wavelength

Competition Between Stripes and Pairing in a t-t'-J Model

As the number of legs n of an n-leg, t-J ladder increases, density matrix renormalization group calculations have shown that the doped state tends to be characterized by a static array of domain walls and that pairing correlations are suppressed. Here we present results for a t-t'-J model in which a diagonal, single particle, next-near-neighbor hopping t' is introduced. We find that this can suppress the formation of stripes and, for t' positive, enhance the d_{x^2-y^2}-like pairing correlations. The effect of t' > 0 is to cause the stripes to evaporate into pairs and for t' < 0 to evaporate into quasi-particles. Results for n=4 and 6-leg ladders are discussed.Comment: Four pages, four encapsulated figure

Linear Optical CNOT Gate in the Coincidence Basis

We describe the operation and tolerances of a non-deterministic, coincidence basis, quantum CNOT gate for photonic qubits. It is constructed solely from linear optical elements and requires only a two-photon source for its demonstration.Comment: Submitted to Physical Review

CCH <i>N</i> = 4-3 emission from dense interstellar clouds

The authors have searched for N = 4 - 3 rotational line emission from the ethynyl radical CCH, at 349 GHz toward a number of galactic molecular clouds. They have detected emission from ten giant molecular clouds and have derived CCH column densities on the order of 1014 - 1015cm-2. They find that CCH emission arises from dense gas, n(H2) ~ 104 - 105cm-3, but not from very dense material, n(H2) > 106cm-3, nor from hot gas such as the "hot core" region in Orion