Polarimetric analysis of stress anisotropy in nanomechanical silicon nitride resonators

We realise a circular gray-field polariscope to image stress-induced birefringence in thin (submicron thick) silicon nitride (SiN) membranes and strings. This enables quantitative mapping of the orientation of principal stresses and stress anisotropy, complementary to, and in agreement with, finite element modeling (FEM). Furthermore, using a sample with a well known stress anisotropy, we extract a new value for the photoelastic (Brewster) coefficient of silicon nitride, $C \approx (3.4~\pm~0.1)\times~10^{-6}~\mathrm{MPa}^{-1}$. We explore possible applications of the method to analyse and quality-control stressed membranes with phononic crystal pattern

Dr. Larry Brewster and California Arts-in-Corrections: A Case Study in Correctional Arts Research

The correctional arts field is strong on supporting anecdotes but light on evidence-based research. In other words, it has more stories than numbers. One exception is the long-running California Arts-in-Corrections program. Not only does AIC have more studies demonstrating benefit, all but one of those studies were conducted by Dr. Larry Brewster, currently of the University of San Francisco. This case study tells the story of how that body of research came to exist. It juxtaposes the importance of having evidence-based research on correctional arts programs with the challenges of conducting such research. Readers will gain an understanding of how correctional arts can benefit rehabilitation and re-entry initiatives for prisoners as well as how rigorous research can aid that effort. This article lays the groundwork for discussion on how an important avenue for rehabilitation and re-entry can be developed by making sure the field has numbers to match the stories

Sound in the interface to a mobile computer

No abstract available

Brewster quasi bound states in the continuum in all-dielectric metasurfaces from single magnetic-dipole resonance meta-atoms

Bound states in the continuum (BICs) are ubiquitous in many areas of physics, attracting especial interest for their ability to confine waves with infinite lifetimes. Metasurfaces provide a suitable platform to realize them in photonics; such BICs are remarkably robust, being however complex to tune in frequency-wavevector space.Here we propose a scheme to engineer BICs and quasi-BICs with single magnetic-dipole resonance meta-atoms. Upon changing the orientation of the magnetic-dipole resonances, we show that the resulting quasi-BICs,emerging from the symmetry-protected BIC at normal incidence, become transparent for plane-wave illumination exactly at the magnetic-dipole angle, due to a Brewster-like effect. While yielding infinite Q-factors at normalincidence(canonical BIC), these are termed Brewster quasi-BICs since a transmission channel is always allowed that slightly widens resonances at oblique incidences. This is demonstrated experimentally through reflectance measurements in the microwave regime with high-refractive-index mm-disk metasurfaces. Such Brewster-inspired configuration is a plausible scenario to achieve quasi-BICs throughout the electromagnetic spectrum inaccessible through plane-wave illumination at given angles, which could be extrapolated to other kind of waves.Comment: 15 pages, 7 figures; typos corrected, Figs. 3 & 5 modified, new Fig. 7 & references adde

Correcting menu usability problems with sound

Future human-computer interfaces will use more than just graphical output to display information. In this paper we suggest that sound and graphics together can be used to improve interaction. We describe an experiment to improve the usability of standard graphical menus by the addition of sound. One common difficulty is slipping off a menu item by mistake when trying to select it. One of the causes of this is insufficient feedback. We designed and experimentally evaluated a new set of menus with much more salient audio feedback to solve this problem. The results from the experiment showed a significant reduction in the subjective effort required to use the new sonically-enhanced menus along with significantly reduced error recovery times. A significantly larger number of errors were also corrected with sound

Conservation of Arabidopsis thaliana photoperiodic flowering time genes in onion (Allium cepa L.)

The genetics underlying onion development is poorly understood. Here the characterisation of onion homologues of Arabidopsis photoperiodic flowering pathway genes is reported with the end goal of accelerating onion breeding programmes by understanding the genetic basis of adaptation to different latitudes. The expression of onion GI, FKF1 and ZTL homologues under SD and LD conditions was examined using quantitative RT-PCR. The expression of AcGI and AcFKF1 was examined in onion varieties which exhibit different daylength responses. Phylogenetic trees were constructed to confirm the identity of the homologues. AcGI and AcFKF1 showed diurnal expression patterns similar to their Arabidopsis counterparts while AcZTL was found to be constitutively expressed. AcGI showed similar expression patterns in varieties which exhibit different daylength responses whereas AcFKF1 showed differences. It is proposed that these differences could contribute to the different daylength responses in these varieties. Phylogenetic analyses showed that all the genes isolated are very closely related to their proposed homologues. The results presented here show that key genes controlling photoperiodic flowering in Arabidopsis are conserved in onion and a role for these genes in the photoperiodic control of bulb initiation is predicted. This theory is supported by expression and phylogenetic data

Human Resource Management Outsourcing in Spanish firms: Evolution over time and implication for devolution

Purpose: The paper aim to explore the evolution in the use of HRO in Spanish firms, and determine the differences in the degree of implementation of HRO since 1999 until 2014, and also analyze the relationship between HR outsourcing and devolution of HR responsibilities to line managers in Spanish organizations. Design/methodology: This paper combines quantitative and qualitative methods. Namely the article is based on international Cranet HRM survey data collected from private and public organizations and also interviews with HR external providers. Findings: The analysis of developments, based on the Cranet surveys and interviews with HR external providers shows that during the past few years there has been an increasing use of HRO in parallel with the tendency to devolve more HR responsibility to line managers. Research limitations/implications: The main limitation of this research is the limitation of data about reasons for devolution that the CRANET questionnaire provides. However, the interviews carried out enrich the survey data with qualitative results. Practical implications: The findings can be used to guide management teams in outsourcing and devolution decisions to maximize benefits to their organizations. Originality/value: This paper is about the evolution of HRO in Spain as a European Union country where published research on HRO and also its implications is relatively limited. The originality of this paper is mainly the involvement of line manager in the outsourcing process which have been poorly analyzed until now.Peer Reviewe

Brewster-angle measurements of sea-surface reflectance using a high resolution spectroradiometer

This paper describes the design, construction and testing of a ship-borne spectroradiometer based on an imaging spectrograph and cooled CCD array with a wavelength range of 350-800 nm and 4 nm spectral sampling. The instrument had a minimum spectral acquisition time of 0.1 s, but in practice data were collected over periods of 10 s to allow averaging of wave effects. It was mounted on a ship's superstructure so that it viewed the sea surface from a height of several metres at the Brewster angle (53 degrees) through a linear polarizing filter. Comparison of sea-leaving spectra acquired with the polarizer oriented horizontally and vertically enabled estimation of the spectral composition of sky light reflected directly from the sea surface. A semi-empirical correction procedure was devised for retrieving water-leaving radiance spectra from these measurements while minimizing the influence of reflected sky light. Sea trials indicated that reflectance spectra obtained by this method were consistent with the results of radiance transfer modelling of case 2 waters with similar concentrations of chlorophyll and coloured dissolved organic matter. Surface reflectance signatures measured at three locations containing blooms of different phytoplankton species were easily discriminated and the instrument was sufficiently sensitive to detect solar-stimulated fluorescence from surface chlorophyll concentrations down to 1 mg m−3

Hotel Recruitment and Selection Practices: The Case of Greek Hotel Industry

open access journalHotel industry, as a service industry, is greatly dependent upon its employees. Recruitment and Selection practices constitute an important starting stage for hotels towards generating an efficient and productive workforce. The present study, by focusing on 5* and 4* hotels, examines the current trends in the implementation and effectiveness of recruitment and selection practices in the Greek hotel industry, controlling for class category, size and ownership. An inferential quantitative research design was used, and an online survey was conducted, using a seven–point questionnaire. The study concludes that hotel industry, at least in Greece, is still using old – fashioned and cost effective recruitment and selection methods. Findings also outline that 5* and 4* hotels do not differentiate their mix of methods used in recruiting and selecting future employees. Internal recruitment methods are mostly considered to be effective in contrast to external recruitment methods. While interviews and reference checks are listed at the top of the effectiveness list of selection methods. The findings of this research enhance industry understanding of the use and effectiveness of recruitment and selection methods and indicate the need for hotels of superior class to re–examine their recruitment and selection methods and adopt more contemporary ones in their mix

Polarization singularities in the clear sky

Ideas from singularity theory provide a simple account of the pattern of polarization directions in daylight. The singularities (two near the Sun and two near the anti-Sun) are points in the sky where the polarization line pattern has index +1/2 and the intensity of polarization is zero. The singularities are caused by multiple scattering that splits into two each of the unstable index +1 singularities at the Sun and anti-Sun, which occur in the single-dipole scattering (Rayleigh) theory. The polarization lines are contours of an elliptic integral. For the intensity of polarization (unnormalized degree), it is necessary to incorporate the strong depolarizing effect of multiple scattering near the horizon. Singularity theory is compared with new digital images of sky polarization, and gives an excellent description of the pattern of polarization directions. For the intensity of polarization, the theory can reproduce not only the zeros but also subtle variations in the polarization maxima