High-performance integrated spectrometers are highly desirable for applications ranging from mobile phones to space probes. Based on silicon photonic integrated circuit technology, we propose and ...demonstrate an on-chip speckle spectrometer consisting of a 15×15, 2D disordered microring lattice. The proposed 2D, disordered microring lattice was simulated by the transfer-matrix method. The fabricated device featured a spectral resolution better than 15 pm and an operating bandwidth larger than 40 nm. We also demonstrated that, based on the speckle patterns, our device can perform a spectrum classification using machine learning algorithms, which will have a huge potential in fast, intelligent material and chemical analysis.
All of the stereoisomeric forms of the surfactant, sodium 3-2-methyl-4,5-bis(hexadecyloxymethyl)-1,3-dioxolan-2-ylpropane-1-sulfonate, have been prepared: the enantiomers (+)-1 and (−)-1, the ...racemate (±)-1 (by two different methods), and meso 2 and meso 3. Vortexed vesicles of these materials were characterized by dynamic laser light scattering, to give vesicle sizes, and by differential scanning calorimetry, to give bilayer phase transition temperatures and associated enthalpies. Different calorimetry results were obtained for (+)-1 (−)-1, (±)-1, 2, and 3. In particular, a comparison of the results for (+)-1 (−)-1 and (±)-1 indicated the operation of enantiomer discrimination. The criteria of the “absolute” method of stereochemistry applied to this study were not completely fulfilled.
This paper introduces permittivity-shielding which enables the measurement of voltage with very few electric field sensors. Voltage sensor designs using permittivity-shielding can exploit existing ...optical sensor technology without the need for the expensive and potentially hazardous insulation found in many modern optical voltage transducers (OVTs). Numerical simulations demonstrate that a voltage sensor consisting of 100 M/spl Omega/ shielding and six electric field sensors, or less, mounted inside an "off-the-shelf" stand-off insulator can achieve IEC 60044-2 0.2 metering class accuracies (<0.2% magnitude error and <10 minutes phase error) even in the presence of strong stray field effects.
•Reconstructive analysis of retrospective, partly biographical interviews with Luxembourgish care leavers.•Care leavers in Luxembourg have to cope with various transitions – such as school-to-work, ...leaving care and secondary-to-tertiary education – in parallel and in a very short time.•Care arrangements in Luxembourg appear to be on an axis of inequalities. The form as well as the duration and consistency of placement favour the (re-)production of (educational) inequality.•There is a strong interdependency between the care system, care arrangements, possible educational achievements, and agency.•The achievement of agency within the heterogeneous and frequently changing constellations for care leavers depends on the experience of reliable relationships, placement stability in school and in care, and necessary social and even financial support.
This article presents empirical results from a study (2015–2018) on young people leaving care in Luxembourg. A special focus deals with the processes of transitioning from care to work. Education appears to be crucial for a successful transition, as it determines life chances, such as labour market chances, but so far inequality studies have neither researched transitions from care nor have the theoretical concepts developed in inequality research been used to understand the situation of care leavers. They might help to explain the different mechanisms behind the disadvantages of students in foster and residential care and their educational attainment. This paper thus attempts to theorise leaving care from an inequality perspective and the interdependencies with concepts of relational agency, taking into account the heterogeneity among care leavers, their trajectories and achievements (see also Göbel, Hadjar, Karl, Peters, & Jäger, 2020). The main objective of our analysis is to investigate how agency is achieved in the transition from school to work among care leavers, taking into consideration institutional pathways (continuities and discontinuities) in the care and the educational system.
The position of the centre of resistance (CR) is an essential parameter regarding the planning of orthodontic tooth movements. In the present investigation, the combined CR of the upper four incisors ...was determined numerically using the finite-element (FE) method. Based on a commercially available three-dimensional data set of a maxilla, including all 16 teeth, as well as known and earlier determined material parameters, FE models of the upper incisors and their surrounding tooth-supporting structures were generated. In the FE system, the model of the anterior segment was loaded with torques of 10 Nmm each at the lateral incisors. The FE model indicated that the individual incisors moved independently, although they were blocked with a steel wire of dimension 0.46 × 0.65 mm2. The individual CRs were located at 5 mm distal and 9 and 12 mm apical to the centre of the lateral brackets. Thus, the classical view of a combined CR for the anterior segment was disproved and the planning of orthodontic tooth movements of the upper incisors should no longer be based on that concept.
Cubic perovskite SrTi1−xMnxO3 nanopowders with x = 0–0.5, which is much higher than the conventionally believed Mn incorporation limit, and particles sizes 10–80 nm have been successfully synthesized ...using the citrate sol–gel method. The crystalline structure, the morphology, the chemical composition and the lattice constant behavior versus the annealing temperature and the Mn concentration have been characterized using X-ray diffraction, scanning electron microscopy and proton-induced X-ray emission techniques. Studies of Raman light scattering and the magnetic properties revealed the activation of the TO2 polar mode and the magnetic ordering effects at low temperatures. Such features are treated as possible evidence of non-d0 Mn-driven transition to a polar phase with multiferroicity in heavily concentrated perovskite SrTi1−xMnxO3 nanopowders.
•Heavily Mn-doped perovskite SrTi1−xMnxO3 nanopowders were firstly synthesized.•Activation of the Last TO2 mode reveals polar ordering at low temperatures.•Appearance of the polar phase is accompanied by magnetic ordering (multiferroicity).
Researchers believe that personality affects both the negotiation process and outcomes, but have yet to provide reliable evidence. Using a culturally balanced personality scale SAPPS, we explore the ...impact of personality on negotiation within a collectivist context-China. Hypothesized relationships based on a buyer/seller model are supported that assertive negotiators are more likely to behave competitively, which leads to better economic outcomes, and open-minded negotiators are more likely to use an integrative approach, which leads to higher satisfaction. This result, similar to those obtained in North America, suggests a universal model of negotiation might exist. Our study also indicates, however, that personality only accounts for a small portion of variance in negotiation behaviors. More research from other perspectives is needed for further exploration. PUBLICATION ABSTRACT
The purpose of this action research study was to expand preservice teacher perspectives on the possibilities of schooling through engagement with nontraditional and progressive learning environments. ...Nine preservice teachers were given the opportunity to experience schools on the learning edge and develop perspectives on what is possible in schooling. Knowledge generated was expected to inform preservice teachers on how schools could serve all student populations within nontraditional learning environments. Study participants and data collected in Cycle 1 consisted of interviewing administrators and alumni students whose focus areas were teaching and learning environments, fieldwork placements and overall experiences in the teacher preparation programs. Action steps including the data collection from school visitations, participant interviews, professional development, and surveys were designed, implemented, and analyzed in Cycle 2. Findings included preservice teachers' expanding their perspectives to what is possible in schooling, student participants learning from professional development and opportunities to visit nontraditional, progressive learning environments. Implications for the organization included establishing partnerships with nontraditional, progressive schools, providing preservice teachers opportunities for school visits, providing a safe place for preservice teachers to share experiences and reflections and structuring opportunities to educate colleagues, administrators, and faculty on the importance of experiences in teaching and learning. The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.
Single- and double-chain quaternary ammonium
O,O′-dialkylphosphorodithioate surfactants
1–
3 were synthesized:
1, hexadecyltrimethylammonium
O,O′-diethylphosphorodithioate;
2a, ...didodecyldimethylammonium
O,O′-dimethylphosphorodithioate;
2b, didodecyldimethylammonium
O,O′-diethylphosphorodithioate;
3, didodecyldimethylammonium
O,O′-didodecylphosphorodithioate. Surfactant
1 was characterized by Krafft temperature and critical micelle concentration measurements, and its aqueous aggregates were characterized by dynamic laser light scattering and
1H NMR spectroscopy. Compounds
2 and
3 are largely insoluble in H
2O, even at temperatures >23
°C. The reaction of micellar
1 with
4 (2-chloroethyl phenyl sulfide), a simulant for the chemical warfare agent mustard bis(2-chloroethyl) sulfide, gave
10
S-2-(phenylthio)ethyl
O,O′-diethylphosphorodithioate in a pH 9.0 borate buffer at 23
°C. The conversion of
4 into
10 corresponds to the decontamination of
4.
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