Estimation of Buttiker-Landauer traversal time based on the visibility of transmission current

We present a proposal for the estimation of B\"uttiker-Landauer traversal time based on the visibility of transmission current. We analyze the tunneling phenomena with a time-dependent potential and obtain the time-dependent transmission current. We found that the visibility is directly connected to the traversal time. Furthermore, this result is valid not only for rectangular potential barrier but also for general form of potential to which the WKB approximation is applicable . We compared these results with the numerical values obtained from the simulation of Nelson's quantum mechanics. Both of them fit together and it shows our method is very effective to measure experimentally the traversal time.Comment: 12 pages, REVTeX, including 7 eps figure

A Q‐methodology study of the type of support mentors need when assessing underperforming nursing students

Aims To identify and describe patterns of the shared viewpoints of nurse mentors about the support obtained from link lecturer in assessing underperforming students. Design Non‐experimental, exploratory research design. Methods Q‐methodology was applied to explore the viewpoints of 26 mentors about support. The data were collected from May–September 2018. During the development of the Q‐set, we combined a naturalistic and theoretical approach, resulting in 27 statements. The participants ranked statements into a Q‐sort grid. PQ‐Method 2.35 software was used to perform a principal component analysis to identify different patterns of the mentors' viewpoints. Results Five factors of shared viewpoints, which accounted for 62% of the total variance, were derived from the factor analysis: (a) Confident in professional assessment and expects respect from link lecturer; (b) confident about the limit but need guidance in documentation. (c) Confident in the assessment but need support to manage concerns; (d) require knowledge and skills but not emotional support; and (e) dialogue and collaboration rather than information. Conclusions Based on our findings, all mentors need different types of support from the link lecturer, depending on their experience as a mentor and nurse and educational credits in mentorship. The central principle identified in this study was that mentors need to feel secure in their role. The accessibility, approachability, and willingness of the link lecturer to participate in dialogue and collaboration are important, but emotional support is not. Impact Our findings provide insights into the type of support mentors need when assessing underperforming students. The findings highlight the necessity of a link lecturer who is accessible and is meeting the mentors' need for knowledge and skills about assessment and mentoring. The nurse education programme must prioritize resources to ensure that the link lecturer can follow‐up with the student and the mentor.publishedVersio

Generation and control of resonance states in crossed magnetic and electric fields

A two-dimensional electron system interacting with an impurity and placed in crossed magnetic and electric fields is under investigation. Since it is assumed that an impurity center interacts as an attractive $\delta$-like potential a renormalization procedure for the retarded Green's function has to be carried out. For the vanishing electric field we obtain a close analytical expression for the Green's function and we find one bound state localized between Landau levels. It is also shown by numerical investigations that switching on the electric field new long-living resonance states localized in the vicinity of Landau levels can be generated.Comment: 6 pages, 6 figures, 1 tabl

Tunneling Time Distribution by means of Nelson's Quantum Mechanics and Wave-Particle Duality

We calculate a tunneling time distribution by means of Nelson's quantum mechanics and investigate its statistical properties. The relationship between the average and deviation of tunneling time suggests the exsistence of ``wave-particle duality'' in the tunneling phenomena.Comment: 14 pages including 11 figures, the text has been revise

Collective Antenna Effects in the Terahertz and Infrared Response of Highly Aligned Carbon Nanotube Arrays

We study macroscopically-aligned single-wall carbon nanotube arrays with uniform lengths via polarization-dependent terahertz and infrared transmission spectroscopy. Polarization anisotropy is extreme at frequencies less than $\sim$3 THz with no sign of attenuation when the polarization is perpendicular to the alignment direction. The attenuation for both parallel and perpendicular polarizations increases with increasing frequency, exhibiting a pronounced and broad peak around 10 THz in the parallel case. We model the electromagnetic response of the sample by taking into account both radiative scattering and absorption losses. We show that our sample acts as an effective antenna due to the high degree of alignment, exhibiting much larger radiative scattering than absorption in the mid/far-infrared range. Our calculated attenuation spectrum clearly shows a non-Drude peak at $\sim$10 THz in agreement with the experiment.Comment: 5 pages, 5 figure

Failing to Fail nursing students among mentors : a confirmatory factor analysis of the Failing to Fail scale

Aim: The aim was to explore the psychometric properties with respect to the internal consistency reliability of the subject‐specific questionnaire “Failing to Fail.” Design: Cross‐sectional study. Methods: Exploratory factor analysis with varimax rotation. A confirmatory factor analysis was used to examine the factor structure of the “Failing to Fail” scale. The sample included 336 Norwegian nurse mentors. Results: The confirmatory factor analysis confirmed a five‐factor structure of the “Failing to Fail” scale with adequate model fit. The factors were named as: (a) Insufficient mentoring competence; (b) Insufficient support in the working environment; (c) Emotional process dominates the assessment; (d) Insufficient support from the university; and (e) Decision‐making detached from learning outcomes. The scale proved to be feasible to test whether mentors are Failing to Fail nursing students. The confirmatory factor analysis model supported the predictive validity of the “Failing to Fail” scale.publishedVersio

Incorporating interactive 3-dimensional graphics in astronomy research papers

Most research data collections created or used by astronomers are intrinsically multi-dimensional. In contrast, all visual representations of data presented within research papers are exclusively 2-dimensional. We present a resolution of this dichotomy that uses a novel technique for embedding 3-dimensional (3-d) visualisations of astronomy data sets in electronic-format research papers. Our technique uses the latest Adobe Portable Document Format extensions together with a new version of the S2PLOT programming library. The 3-d models can be easily rotated and explored by the reader and, in some cases, modified. We demonstrate example applications of this technique including: 3-d figures exhibiting subtle structure in redshift catalogues, colour-magnitude diagrams and halo merger trees; 3-d isosurface and volume renderings of cosmological simulations; and 3-d models of instructional diagrams and instrument designs.Comment: 18 pages, 7 figures, submitted to New Astronomy. For paper with 3-dimensional embedded figures, see http://astronomy.swin.edu.au/s2plot/3dpd

Condensation of Ideal Bose Gas Confined in a Box Within a Canonical Ensemble

We set up recursion relations for the partition function and the ground-state occupancy for a fixed number of non-interacting bosons confined in a square box potential and determine the temperature dependence of the specific heat and the particle number in the ground state. A proper semiclassical treatment is set up which yields the correct small-T-behavior in contrast to an earlier theory in Feynman's textbook on Statistical Mechanics, in which the special role of the ground state was ignored. The results are compared with an exact quantum mechanical treatment. Furthermore, we derive the finite-size effect of the system.Comment: 18 pages, 8 figure