2,929 research outputs found
Transport current dependence of the hysterisis loss in silver sheathed BSCCO-2212 conductors
A technique is described to study the critical current density and penetration fieldassociated with the transport current in a silver sheathed BSCCO conductor. A transport current flowing in a conductor in a varying magnetic field will only influence magnetisation currents that are in competition with the transport current, i.e. currents that use the same path. By measuring the transport current dependence of the magnetisation loss information can be obtained on the related critical current and penetration field. The combination of these two quantities contains information about the geometry of the current distribution and can be used to test different models for the current distribution in BSCCO conductors
Recommended from our members
The efficacy of speech intervention using electopalatography with an 18 year old deaf client: A single case study
This single case study explored the use of EPG as a therapeutic tool for treating inaccurate articulation of the voiceless alveolar plosive /t/. The participant (M) is an 18-year-old deaf adult who consistently uses hearing aids, and who communicates using a combination of English, Sign Supported English and British Sign Language (BSL). M received traditional phonological therapy targeting his production of /t/ prior to EPG therapy, but without success. He requested further therapy and EPG was offered as an alternative approach. Pre-EPG therapy, M made tongue placement errors for both /t/ and the voiced alveolar plosive /d/. Based on perceptual analysis by M’s speech and language therapist, the first author, his productions were inconsistent, though generally perceived as voiceless and voiced velar plosives respectively. The EPG therapy consisted of 6 bi-weekly therapy sessions, each lasting for one hour, targeting M’s production of /t/ in familiar words, using the visual feedback from the EPG display. Trained and untrained listeners perceptually analysed audio recordings of words and sentences collected at 3 assessment points. Improvements, both over the course of the EPG therapy and during the follow-up period, were found to be statistically significant. Significantly, M was able to generalise his production skills to untaught words containing both /t/ and /d/. Equally significant was the lack of change in M’s production of a control sound, the voiceless dental fricative /θ/. More globally, an improvement was observed in ratings of M’s intelligibility in sentences and in his voice quality (assessed impressionistically)
Optically Induced Modulation of a Laser Beam in Nematic Liquid Crystals Structures
In this paper we report the experimental results obtained when an He-Ne laser beam crosses an MBBA homeotropic sandwich structure and is modulated by the influence of another laser beam, in our case an Ar+ laser, crossing through the same region. We extend some results previously reported by us1 2 concerning the influence of the ratio of the diameters of the laser beams on the modulation characteristics. A theoretical model, based on the one reported in Ref6 , shows good agreement with the
experimental results. If the Ar+ laser is intensity chopped, the resulting He-Ne diffracted image is also intensity modulated. The highest frequency observed has been 500 p. p. s
An Improved Implementation and Abstract Interface for Hybrid
Hybrid is a formal theory implemented in Isabelle/HOL that provides an
interface for representing and reasoning about object languages using
higher-order abstract syntax (HOAS). This interface is built around an HOAS
variable-binding operator that is constructed definitionally from a de Bruijn
index representation. In this paper we make a variety of improvements to
Hybrid, culminating in an abstract interface that on one hand makes Hybrid a
more mathematically satisfactory theory, and on the other hand has important
practical benefits. We start with a modification of Hybrid's type of terms that
better hides its implementation in terms of de Bruijn indices, by excluding at
the type level terms with dangling indices. We present an improved set of
definitions, and a series of new lemmas that provide a complete
characterization of Hybrid's primitives in terms of properties stated at the
HOAS level. Benefits of this new package include a new proof of adequacy and
improvements to reasoning about object logics. Such proofs are carried out at
the higher level with no involvement of the lower level de Bruijn syntax.Comment: In Proceedings LFMTP 2011, arXiv:1110.668
Exact solutions to the four Goldstone modes around a dark soliton of the nonlinear Schroedinger equation
This article is concerned with the linearisation around a dark soliton
solution of the nonlinear Schr\"odinger equation. Crucially, we present
analytic expressions for the four linearly-independent zero eigenvalue
solutions (also known as Goldstone modes) to the linearised problem. These
solutions are then used to construct a Greens matrix which gives the
first-order spatial response due to some perturbation. Finally we apply this
Greens matrix to find the correction to the dark-soliton wavefunction of a
Bose-Einstein condensate in the presence of fluctuations.Comment: 14 pages, 3 figures, submitted to Journal of Physics
Knowledge-Attitudes-Practices About Malaria Among Communities in Southern Benin
Malaria still remains the main public health problem in Benin. We explored the determinants that influenced malaria treatment as well as protective behaviors, to generate a framework of useful ideas as alternative strategies against malaria. A cross-sectional survey of the knowledge, attitudes and practices (KAP) was conducted at Hozin, Vakon and Agblangandan districts in southern region of Benin. Descriptive statistics were computed and mixed logistic regression helped evaluating the relationship between frequency of each category of severity of malaria and sex group, educational level, treatment, means of self-protection against mosquitoes and identification of the cause of malaria. A significant proportion 750 (81.3%) (p<0.001) of participants stated that malaria was caused by mosquitoes. The respondents who mentioned sun as the cause of malaria, have trivialized more malaria in a proportion of about 59.30% (OR=2.67 [95% CI 1.61-4.44]) followed by those who have reported the cause of body weakness (43.68%) (OR=2.97 [95% CI 1.68-5.28]). Poor knowledge justifies the trivialization of the disease and poor management of malaria control means. National Malaria Control Programs should improve access to education, especially for women and could help improving prevention and control behaviours against malaria in communities
Gas-Kinetic-Based Traffic Model Explaining Observed Hysteretic Phase Transition
Recently, hysteretic transitions to `synchronized traffic' with high values
of both density and traffic flow were observed on German freeways [B. S. Kerner
and H. Rehborn, Phys. Rev. Lett. 79, 4030 (1997)]. We propose a macroscopic
traffic model based on a gas-kinetic approach that can explain this phase
transition. The results suggest a general mechanism for the formation of
probably the most common form of congested traffic.Comment: With corrected formula (3). For related work see
http://www.theo2.physik.uni-stuttgart.de/helbing.htm
- …