17,301 research outputs found
High voltage solid-state relay
Hybrid microelectronics relay has characteristics significantly superior to conventional solid state relays. Relay provides 2500 Vdc input to output isolation and operates from high threshold logic signal to switch load of 400 Vdc at 2 mA. Technology should be of interest to manufacturers of discrete components
Perceptions of physiotherapists towards research: a mixed methods study
OBJECTIVES: To explore the perceptions of physiotherapists towards the use of and participation in research.
DESIGN: Concurrent mixed methods research, combining in-depth interviews with three questionnaires (demographics, Edmonton Research Orientation Survey, visual analogue scales for confidence and motivation to participate in research).
SETTING: One physiotherapy department in a rehabilitation hospital, consisting of seven specialised areas.
PARTICIPANTS: Twenty-five subjects {four men and 21 women, mean age 38 [standard deviation (SD) 11] years} who had been registered as a physiotherapist for a mean period of 15 (SD 10) years participated in this study. They were registered with the New Zealand Board of Physiotherapy, held a current practising certificate, and were working as a physiotherapist or physiotherapy/allied health manager at the hospital.
MAIN OUTCOME MEASURE: The primary outcome measure was in-depth interviews and the secondary outcome measures were the three questionnaires.
RESULTS: Physiotherapists were generally positive towards research, but struggled with the concept of research, the available literature and the time to commit to research. Individual confidence and orientation towards research seemed to influence how these barriers were perceived.
CONCLUSION: This study showed that physiotherapists struggle to implement research in their daily practice and become involved in research. Changing physiotherapists' conceptions of research, making it more accessible and providing dedicated research time could facilitate increased involvement in the physiotherapy profession
On Critical Exponents and the Renormalization of the Coupling Constant in Growth Models with Surface Diffusion
It is shown by the method of renormalized field theory that in contrast to a
statement based on a mathematically ill-defined invariance transformation and
found in most of the recent publications on growth models with surface
diffusion, the coupling constant of these models renormalizes nontrivially.
This implies that the widely accepted supposedly exact scaling exponents are to
be corrected. A two-loop calculation shows that the corrections are small and
these exponents seem to be very good approximations.Comment: 4 pages, revtex, 2 postscript figures, to appear in Phys.Rev.Let
Monolithic microwave integrated circuit water vapor radiometer
A proof of concept Monolithic Microwave Integrated Circuit (MMIC) Water Vapor Radiometer (WVR) is under development at the Jet Propulsion Laboratory (JPL). WVR's are used to remotely sense water vapor and cloud liquid water in the atmosphere and are valuable for meteorological applications as well as for determination of signal path delays due to water vapor in the atmosphere. The high cost and large size of existing WVR instruments motivate the development of miniature MMIC WVR's, which have great potential for low cost mass production. The miniaturization of WVR components allows large scale deployment of WVR's for Earth environment and meteorological applications. Small WVR's can also result in improved thermal stability, resulting in improved calibration stability. Described here is the design and fabrication of a 31.4 GHz MMIC radiometer as one channel of a thermally stable WVR as a means of assessing MMIC technology feasibility
The relationship between students’ writing process, text quality, and thought process quality in 11th-grade history and philosophy assignments
The relationship between students’ writing process, text quality, and thought process quality in 11th-grade history and philosophy assignments
Quantum simulation of a Fermi-Hubbard model using a semiconductor quantum dot array
Interacting fermions on a lattice can develop strong quantum correlations,
which lie at the heart of the classical intractability of many exotic phases of
matter. Seminal efforts are underway in the control of artificial quantum
systems, that can be made to emulate the underlying Fermi-Hubbard models.
Electrostatically confined conduction band electrons define interacting quantum
coherent spin and charge degrees of freedom that allow all-electrical
pure-state initialisation and readily adhere to an engineerable Fermi-Hubbard
Hamiltonian. Until now, however, the substantial electrostatic disorder
inherent to solid state has made attempts at emulating Fermi-Hubbard physics on
solid-state platforms few and far between. Here, we show that for gate-defined
quantum dots, this disorder can be suppressed in a controlled manner. Novel
insights and a newly developed semi-automated and scalable toolbox allow us to
homogeneously and independently dial in the electron filling and
nearest-neighbour tunnel coupling. Bringing these ideas and tools to fruition,
we realize the first detailed characterization of the collective Coulomb
blockade transition, which is the finite-size analogue of the
interaction-driven Mott metal-to-insulator transition. As automation and device
fabrication of semiconductor quantum dots continue to improve, the ideas
presented here show how quantum dots can be used to investigate the physics of
ever more complex many-body states
Disordered Electrons in a Strong Magnetic Field: Transfer Matrix Approaches to the Statistics of the Local Density of States
We present two novel approaches to establish the local density of states as
an order parameter field for the Anderson transition problem. We first
demonstrate for 2D quantum Hall systems the validity of conformal scaling
relations which are characteristic of order parameter fields. Second we show
the equivalence between the critical statistics of eigenvectors of the
Hamiltonian and of the transfer matrix, respectively. Based on this equivalence
we obtain the order parameter exponent for 3D quantum
Hall systems.Comment: 4 pages, 3 Postscript figures, corrected scale in Fig.
Aging in the glass phase of a 2D random periodic elastic system
Using RG we investigate the non-equilibrium relaxation of the (Cardy-Ostlund)
2D random Sine-Gordon model, which describes pinned arrays of lines. Its
statics exhibits a marginal () glass phase for described by a
line of fixed points. We obtain the universal scaling functions for two-time
dynamical response and correlations near for various initial conditions,
as well as the autocorrelation exponent. The fluctuation dissipation ratio is
found to be non-trivial and continuously dependent on .Comment: 5 pages, RevTex, Modified Versio
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