AEM of extraterrestrial materials

Modifications to and maintenance of the JEOL 100 CX electron microscope are discussed. Research activity involving extraterrestrial matter, cosmic dust, stratosphere dust, and meteorites is summarized

Devolution as process: institutional structures, state personnel and transport policy in the United Kingdom

Devolution has been described as a key ‘global trend’ over recent decades as governments have decentralised power and responsibilities to subordinate regional institutions (Rodriguez-Pose and Gill, 2003). UK devolution is characterised by its asymmetrical nature with different territories granted different institutional arrangements and powers. In this paper, we seek examine the role of state personnel in mobilising the new institutional machinery and managing the process of devolution, focusing on transport policy. Our research shows a clear contrast between London and Northern Ireland, on the one hand, and Scotland and Wales, on the other, in terms of the effectiveness of political leaders in creating clear policy priorities and momentum in transport

Comparative Analysis of Non-thermal Emissions and Study of Electron Transport in a Solar Flare

We study the non-thermal emissions in a solar flare occurring on 2003 May 29 by using RHESSI hard X-ray (HXR) and Nobeyama microwave observations. This flare shows several typical behaviors of the HXR and microwave emissions: time delay of microwave peaks relative to HXR peaks, loop-top microwave and footpoint HXR sources, and a harder electron energy distribution inferred from the microwave spectrum than from the HXR spectrum. In addition, we found that the time profile of the spectral index of the higher-energy (\gsim 100 keV) HXRs is similar to that of the microwaves, and is delayed from that of the lower-energy (\lsim 100 keV) HXRs. We interpret these observations in terms of an electron transport model called {\TPP}. We numerically solved the spatially-homogeneous {\FP} equation to determine electron evolution in energy and pitch-angle space. By comparing the behaviors of the HXR and microwave emissions predicted by the model with the observations, we discuss the pitch-angle distribution of the electrons injected into the flare site. We found that the observed spectral variations can qualitatively be explained if the injected electrons have a pitch-angle distribution concentrated perpendicular to the magnetic field lines rather than isotropic distribution.Comment: 32 pages, 12 figures, accepted for publication in The Astronomical Journa

Practising Power: Parent-Teacher Consultations in Early Years Settings

This research explores parent-teacher consultations in a range of early years settings. Data were collected from eighteen audio-recorded parent-teacher consultations from six different settings and from follow up interviews with parents and teachers. The data related to the consultations and participants’ direct experience of these and revealed the practices of power within these consultations. Using a Foucauldian approach to analysis, the exercise of power and its impact on the parent-teacher relationship was explored. The analysis revealed the ways in which surveillance, normalising judgements and the ‘examination’ of all involved in the reporting process to parents, constitutes an exercise of power. Within the consultation parents, teachers and children are positioned as subjects who are homogenised and judged accordingly. Conversely, the presentation of observations and assessment information leads to the individualisation of children, allowing classifications and comparisons to be made in relation to a particular set of ‘truths’ about what it is to be a child, a parent and a teacher. Throughout the consultations parents and teachers assert and defend their positions and in doing so, attempts at resistance are evident. The findings of the research open up new possibilities for challenging existing modes of practice in parent-teacher consultations. These include implications for initial teacher education and CPD programmes, in order to develop awareness of the way in which power is exercised through parent-teacher interactions and the effects it can have. The need for policy makers to take greater account of the exercise of power when developing policies in relation to partnership with parents, and indeed in evaluating the impact of existing policy is also identified

Comment on the paper I. M. Suslov: Finite Size Scaling from the Self Consistent Theory of Localization

In the recent paper [I.M.Suslov, JETP {\bf 114} (2012) 107] a new scaling theory of electron localization was proposed. We show that numerical data for the quasi-one dimensional Anderson model do not support predictions of this theory.Comment: Comment on the paper arXiv 1104.043

Time-dependent quantum transport in a resonant tunnel junction coupled to a nanomechanical oscillator

We present a theoretical study of time-dependent quantum transport in a resonant tunnel junction coupled to a nanomechanical oscillator within the non-equilibrium Green's function technique. An arbitrary voltage is applied to the tunnel junction and electrons in the leads are considered to be at zero temperature. The transient and the steady state behavior of the system is considered here in order to explore the quantum dynamics of the oscillator as a function of time. The properties of the phonon distribution of the nanomechnical oscillator strongly coupled to the electrons on the dot are investigated using a non-perturbative approach. We consider both the energy transferred from the electrons to the oscillator and the Fano factor as a function of time. We discuss the quantum dynamics of the nanomechanical oscillator in terms of pure and mixed states. We have found a significant difference between a quantum and a classical oscillator. In particular, the energy of a classical oscillator will always be dissipated by the electrons whereas the quantum oscillator remains in an excited state. This will provide useful insight for the design of experiments aimed at studying the quantum behavior of an oscillator.Comment: 24 pages, 10 figure

Finite-size scaling from self-consistent theory of localization

Accepting validity of self-consistent theory of localization by Vollhardt and Woelfle, we derive the finite-size scaling procedure used for studies of the critical behavior in d-dimensional case and based on the use of auxiliary quasi-1D systems. The obtained scaling functions for d=2 and d=3 are in good agreement with numerical results: it signifies the absence of essential contradictions with the Vollhardt and Woelfle theory on the level of raw data. The results \nu=1.3-1.6, usually obtained at d=3 for the critical exponent of the correlation length, are explained by the fact that dependence L+L_0 with L_0>0 (L is the transversal size of the system) is interpreted as L^{1/\nu} with \nu>1. For dimensions d\ge 4, the modified scaling relations are derived; it demonstrates incorrectness of the conventional treatment of data for d=4 and d=5, but establishes the constructive procedure for such a treatment. Consequences for other variants of finite-size scaling are discussed.Comment: Latex, 23 pages, figures included; additional Fig.8 is added with high precision data by Kramer et a

Metal-insulator transition in three dimensional Anderson model: universal scaling of higher Lyapunov exponents

Numerical studies of the Anderson transition are based on the finite-size scaling analysis of the smallest positive Lyapunov exponent. We prove numerically that the same scaling holds also for higher Lyapunov exponents. This scaling supports the hypothesis of the one-parameter scaling of the conductance distribution. From the collected numerical data for quasi one dimensional systems up to the system size 24 x 24 x infinity we found the critical disorder 16.50 < Wc < 16.53 and the critical exponent 1.50 < \nu < 1.54. Finite-size effects and the role of irrelevant scaling parameters are discussed.Comment: 4 pages, 2 figure