Modeling of grating assisted standing wave microresonators for filter applications in integrated optics

A wide, multimode segment of a dielectric optical waveguide, enclosed by Bragg reflectors and evanescently coupled to adjacent port waveguides, can constitute the cavity in an integrated optical microresonator. It turns out that the device can be described adequately in terms of an approximate coupled mode theory model which involves only a few guided modes as basis fields. By reasoning along the coupled mode model, we motivate a simple design strategy for the resonator device. Rigorous two dimensional mode expansion simulations are applied to verify the predictions of the approximate model. The results exemplify the specific spectral response of the standing wave resonators. As refinements we discuss the single resonance of a device with nonsymmetrically detuned Bragg reflectors, and the cascading of two Fabry-Perot cavities, where the coupling across an intermediate shorter grating region establishes a power transfer characteristic that is suitable for an add-drop filter

De bewogen arts

Tijdens het handelen in de medische werkpraktijk worden artsen soms emotioneel geraakt. De probleemstelling bepleit dat artsen hun emoties om verschillende redenen onderdrukken; het uiten van emoties wordt door artsen geassocieerd met schaamte, zwakte en incompetentie. Deze onderdrukking heeft echter negatieve gevolgen voor de gezondheid van artsen: het kan op termijn resulteren in emotional fatigue, burn-out en posttraumatisch stress-syndroom. DOELSTELLING Dit onderzoek maakt inzichtelijk hoe artsen omgaan met momenten waarop zij emotioneel geraakt worden in de medische werkpraktijk. Tevens maakt het duidelijk in welke situaties artsen emotionele geraaktheid ervaren, hoe zij daar uiting aan geven, wat de gevolgen zijn voor hun handelen en welke behoeften zij hebben bij de omgang met emotionele geraaktheid. METHODE Dit is een kwalitatief empirisch fenomenologisch onderzoek. Het onderzoek staat daarmee expliciet open voor de betekenissen die respondenten aan emotionele geraaktheid toekennen. Er zijn semigestructureerde interviews afgenomen bij 12 artsen. Hierbij is tevens een topiclist aangehouden (zie bijlage 7.2). De interviews zijn opgenomen en geanalyseerd door middel van drie coderingsfasen: open codering (1), axiale codering (2) en selectieve codering (3). RESULTATEN Artsen worden emotioneel geraakt in zowel relationele situaties als in technische situaties. De emotionele geraaktheid van artsen beïnvloedt de mate waarin zij controle ervaren tijdens het medisch-technisch handelen en de mate waarin zij hun patiënten kunnen ondersteunen. Omdat artsen controlebehoud tijdens medisch-technisch handelen en ondersteuning van patiënten van groot belang vinden, staan zij steeds voor de afweging in hoeverre zij emoties willen toelaten. CONCLUSIE Artsen willen emotionele geraaktheid met collega’s kunnen delen, zonder dat collega’s hen daarop veroordelen of als minder competent gaan bezien. Artsen hebben behoefte aan steun van collega’s en het thuisfront. De resultaten laten echter zien dat de ervaringen van artsen in de privésfeer soms als te heftig worden ervaren, waardoor partners en vrienden hen niet altijd steun kunnen bieden. Een teamsfeer waarin emotionele geraaktheid getoond en besproken kan worden, blijkt eveneens niet vanzelfsprekend. Artsen zoeken een nieuwe norm met betrekking tot de positie van- en omgang met emotionele geraaktheid binnen de medische werkpraktijk

Optically Transparent Composite Material and Process for Preparing Same

Glass ribbon-reinforced transparent polymer composites which provide excellent optical transparency and a low distortion level over a wide temperature range while exhibiting superior mechanical properties as compared to non- reinforced polymer counterparts, and equivalent properties as compared to glass fiber-reinforced counterparts

Casting Alloys: the Materials and "the Clinical Effects"

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67282/2/10.1177_08959374920060011101.pd

One-loop matching for quark dipole operators in a gradient-flow scheme

The quark chromoelectric dipole (qCEDM) operator is a CP-violating operator describing, at hadronic energies, beyond-the-standard-model contributions to the electric dipole moment of particles with nonzero spin. In this paper we define renormalized dipole operators in a regularization-independent scheme using the gradient flow, and we perform the matching at one loop in perturbation theory to renormalized operators of the same and lower dimension in the more familiar MS scheme. We also determine the matching coefficients for the quark chromo-magnetic dipole operator (qCMDM), which contributes for example to matrix elements relevant to CP-violating and CP-conserving kaon decays. The calculation provides a basis for future lattice QCD computations of hadronic matrix elements of the qCEDM and qCMDM operators

Adaptive Step Size for Hybrid Monte Carlo Algorithm

We implement an adaptive step size method for the Hybrid Monte Carlo a lgorithm. The adaptive step size is given by solving a symmetric error equation. An integr ator with such an adaptive step size is reversible. Although we observe appreciable variations of the step size, the overhead of the method exceeds its benefits. We propose an explanation for this phenomenon.Comment: 13 pages, 5 Postscript figures, late

A Symmetric Integrator for non-integrable Hamiltonian Relativistic Systems

By combining a standard symmetric, symplectic integrator with a new step size controller, we provide an integration scheme that is symmetric, reversible and conserves the values of the constants of motion. This new scheme is appropriate for long term numerical integrations of geodesic orbits in spacetime backgrounds, whose corresponding Hamiltonian system is non-integrable, and, in general, for any non-integrable Hamiltonian system whose kinetic part depends on the position variables. We show by numerical examples that the new integrator is faster and more accurate i) than the standard symplectic integration schemes with or without standard adaptive step size controllers and ii) than an adaptive step Runge-Kutta scheme.Comment: 12 pages, 8 figures, 3 table

I would never take preventive medication! Perspectives and information needs of people who underwent predictive tests for rheumatoid arthritis

Objective: Little is known about the experiences, values and needs of people without arthritis who undergo predictive biomarker testing for the development of rheumatoid arthritis (RA). Our study aimed to explore the perspectives of these individuals and describe their information needs. Methods: A qualitative, multicenter interview study with a thematic analysis was conducted in Austria, Germany and the UK. Individuals who underwent predictive biomarker testing for RA and had a positive test result, but no diagnosis of any inflammatory joint disease, were interviewed. Participants included patients with arthralgia and asymptomatic individuals. Information and education needs were developed from the qualitative codes and themes using the Arthritis Educational Needs Assessment Tool (ENAT) as a frame of reference. Results: Thematic saturation was reached in 34 individuals (76% female; 24 [71%] with arthralgia and 10 [29%] asymptomatic individuals). Thirty‐seven codes were summarized into four themes, namely (i) decision making around whether to undergo initial predictive testing, (ii) willingness to consider further predictive tests and/or (iii) preventive interventions, including medication and (iv) varying reactions after receiving a positive test result. Individuals with arthralgia were more likely to be willing to take preventive action, undergo further testing, and experience psychological distress than asymptomatic individuals. All participants expressed the need for tailored, lay‐understandable information. Conclusion: Individuals at risk of RA are currently the subjects of research aimed at developing better predictive strategies and preventive approaches. Their perceptions and needs should be addressed to inform the future development of interventions combined with education