The pitch-heave dynamics of transportation vehicles

The analysis and design of suspensions for vehicles of finite length using pitch-heave models is presented. Dynamic models for the finite length vehicle include the spatial distribution of the guideway input disturbance over the vehicle length, as well as both pitch and heave degrees-of-freedom. Analytical results relate the vehicle front and rear accelerations to the pitch and heave natural frequencies, which are functions of vehicle suspension geometry and mass distribution. The effects of vehicle asymmetry and suspension contact area are evaluated. Design guidelines are presented for the modification of vehicle and suspension parameters to meet alternative ride quality criteria

Premium: An R package for profile regression mixture models using dirichlet processes

PReMiuM is a recently developed R package for Bayesian clustering using a Dirichlet process mixture model. This model is an alternative to regression models, nonparametrically linking a response vector to covariate data through cluster membership (Molitor, Papathomas, Jerrett, and Richardson 2010). The package allows binary, categorical, count and continuous response, as well as continuous and discrete covariates. Additionally, predictions may be made for the response, and missing values for the covariates are handled. Several samplers and label switching moves are implemented along with diagnostic tools to assess convergence. A number of R functions for post-processing of the output are also provided. In addition to fitting mixtures, it may additionally be of interest to determine which covariates actively drive the mixture components. This is implemented in the package as variable selection

Reaction Diffusion and Ballistic Annihilation Near an Impenetrable Boundary

The behavior of the single-species reaction process $A+A\to O$ is examined near an impenetrable boundary, representing the flask containing the reactants. Two types of dynamics are considered for the reactants: diffusive and ballistic propagation. It is shown that the effect of the boundary is quite different in both cases: diffusion-reaction leads to a density excess, whereas ballistic annihilation exhibits a density deficit, and in both cases the effect is not localized at the boundary but penetrates into the system. The field-theoretic renormalization group is used to obtain the universal properties of the density excess in two dimensions and below for the reaction-diffusion system. In one dimension the excess decays with the same exponent as the bulk and is found by an exact solution. In two dimensions the excess is marginally less relevant than the bulk decay and the density profile is again found exactly for late times from the RG-improved field theory. The results obtained for the diffusive case are relevant for Mg$^{2+}$ or Cd$^{2+}$ doping in the TMMC crystal's exciton coalescence process and also imply a surprising result for the dynamic magnetization in the critical one-dimensional Ising model with a fixed spin. For the case of ballistic reactants, a model is introduced and solved exactly in one dimension. The density-deficit profile is obtained, as is the density of left and right moving reactants near the impenetrable boundary.Comment: to appear in J. Phys.

Cross and magnetic helicity in the outer heliosphere from Voyager 2 observations

Plasma velocity and magnetic field measurements from the Voyager 2 mission are used to study solar wind turbulence in the slow solar wind at two different heliocentric distances, 5 and 29 astronomical units, sufficiently far apart to provide information on the radial evolution of this turbulence. The magnetic helicity and the cross-helicity, which express the correlation between the plasma velocity and the magnetic field, are used to characterize the turbulence. Wave number spectra are computed by means of the Taylor hypothesis applied to time resolved single point Voyager 2 measurements. The overall picture we get is complex and difficult to interpret. A substantial decrease of the cross-helicity at smaller scales (over 1-3 hours of observation) with increasing heliocentric distance is observed. At 5 AU the only peak in the probability density of the normalized residual energy is negative, near -0.5. At 29 AU the probability density becomes doubly peaked, with a negative peak at -0.5 and a smaller peak at a positive values of about 0.7. A decrease of the cross-helicity for increasing heliocentric distance is observed, together with a reduction of the unbalance toward the magnetic energy of the energy of the fluctuations. For the smaller scales, we found that at 29 AU the normalized polarization is small and positive on average (about 0.1), it is instead zero at 5 AU. For the larger scales, the polarization is low and positive at 5 AU (average around 0.1) while it is negative (around - 0.15) at 29 AU.Comment: 14 pages 5 figures. Accepted for publication on European Journal of Mechanics B/Fluids (5/8/2015

Turbulence in the solar wind: spectra from Voyager 2 data at 5 AU

Fluctuations in the flow velocity and magnetic fields are ubiquitous in the Solar System. These fluctuations are turbulent, in the sense that they are disordered and span a broad range of scales in both space and time. The study of solar wind turbulence is motivated by a number of factors all keys to the understanding of the Solar Wind origin and thermodynamics. The solar wind spectral properties are far from uniformity and evolve with the increasing distance from the sun. Most of the available spectra of solar wind turbulence were computed at 1 astronomical unit, while accurate spectra on wide frequency ranges at larger distances are still few. In this paper we consider solar wind spectra derived from the data recorded by the Voyager 2 mission during 1979 at about 5 AU from the sun. Voyager 2 data are an incomplete time series with a voids/signal ratio that typically increases as the spacecraft moves away from the sun (45% missing data in 1979), making the analysis challenging. In order to estimate the uncertainty of the spectral slopes, different methods are tested on synthetic turbulence signals with the same gap distribution as V2 data. Spectra of all variables show a power law scaling with exponents between -2.1 and -1.1, depending on frequency subranges. Probability density functions (PDFs) and correlations indicate that the flow has a significant intermittency.Comment: 14 pages, 7 figures. Discussion improved since the previous versio

The Potential Impact of a Texas High Plains Ethanol Plant on Local Water Supplies

With the passage of the Energy Policy Act, the rapidly expanding number of ethanol plants, and the fury with which ethanol is being promoted, it is clear that ethanol will play a rising role in our domestic energy supply. Along with this rise there will be an increase in the consumptive use of water by ethanol production facilities. Regions, such as the Texas High Plains, that are already considered to be water stressed have the potential of being impacted. The objective of this research is to assess the potential impact the addition of an ethanol plant may have on the Texas High Plains and to determine how increased water costs will transform the economic viability of an ethanol plant.Resource /Energy Economics and Policy,

Celebrity privacy and benefits of simple history

© Cambridge University Press 2006 and Cambridge University Press, 2009. Introduction: Is personal revelation the right of the subject alone or can others tell the story even without consent? The question lies at the heart of recent celebrity privacy cases. When Michael Douglas and Catherine Zeta-Jones claimed their wedding party had been intercepted by underground paparazzi with the photographs to be published in Hello!, their complaint was not that they should be let alone completely. Indeed they had contracted with OK! to give the public account of their celebration with carefully vetted authorised pictures. Yet they claimed their privacy was implicated and the equitable action for breach of confidence was the way to protect this; a claim partly and with some reservations accepted by the courts, which refused an interlocutory injunction but subsequently allowed damages for the unauthorised publication (at the time suggesting the injunction should have been awarded). When Naomi Campbell found herself the subject of an article in the Mirror revealing details of her treatment for a drug addiction, with covertly taken photographs in support, her essential complaint was that the story had been obtained and published without her knowledge or approval (although conceding that her own previous false accounts meant she was in no position to prevent telling about her addiction). Further, the House of Lords left her the option in finding her confidence breached

Highly sensitive alkane odour sensors based on functionalised gold nanoparticles

We deposit dense, ordered, thin films of Au-dodecanethiol core/shell nanoparticles by the Langmuir-Schafer (LS) printing method, and find that their resistance at ambient temperature responds selectively and sensitively to alkane odours. Response is a rapid resistance increase due to swelling, and is strongest for alkane odours where the alkane chain is similar in length to the dodecane shell. For decane odours, we find a response to concentrations as low as 15 ppm, about 600 times below the lower explosive limit. Response is weaker, but still significant, to aromatic odours (e.g. Toluene, Xylene), while potential interferants such as polar and/or hydrogen-bonding odours (e.g. alcohols, ketones, water vapour) are somewhat rejected. Resistance is weakly dependent on temperature, and recovers rapidly and completely to its original value within the error margin of measurement. (C) 2011 Elsevier B.V. All rights reserved

Mentoring trainee psychologists: learning from lived experience

Purpose – To examine service-users’ experiences of mentoring trainee clinical psychologists as part of an involvement initiative on a doctoral training course. Methodology – Seven service-users were paired with trainee clinical psychologists. Pairs met for one hour monthly over 6 months. Meetings were unstructured, lacked a formal agenda and were not evaluated academically. All seven mentors were interviewed. They were asked about positive and negative experiences, as well as about the support provided. Transcripts were subject to thematic analysis and themes were reviewed by mentors in a follow-up meeting. Findings - Overall, results demonstrate that service-users can be involved in training in a way that they find meaningful and contributes to their recovery. Seven themes were identified: Giving hope and optimism; making a difference; personal and professional development; the process; practicalities/ logistics; support (positives); support (areas for improvement). Practical implications – The importance of designing involvement initiatives in a way which implicitly supports service-user values was highlighted. Recommendations for designing effective support structures are given. Authors were also involved in the scheme which could have introduced bias. Originality/value – Research exploring service-users’ experiences of involvement in training health professionals is limited. This was the first study to explore in depth service users’ perspectives of involvement in a scheme such as the Mentoring Scheme. If initiatives are to seriously embrace the values of the service-user movement then seeking service-users’ perspectives is vital. Paper type: Research Pape

Problems in the Removal of Federal Civil Servants

The publicity given in the past few years to the loyalty and security program has brought the civil servant of the federal government increasingly before the public eye. At the same time little attention has been paid to the plight of a civil servant who is dismissed from his post for reasons other than those relating to loyalty and security. It is the purpose of this paper to consider different aspects of the removal of civil servants. We shall discuss (1) the government\u27s power to remove civil servants both at common law and under statutes which deal with the exercise of the removal power, (2) the procedural remedies available to a government worker ousted from office, (3) the loyalty program, and (4) the effect of the invocation by a civil servant of the privilege against self-incrimination