Phase sensitive absolute amplitude detection of surface vibrations using homodyne interferometry without active stabilization

A detection scheme for obtaining phase and absolute amplitude information of surface vibrations on microacoustic components using homodyne laser interferometry is described. The scheme does not require active stabilization of the optical path length of the interferometer. The detection setup is realized in a homodyneMichelson interferometer configuration, and selected measurements on a 374 MHz surface acoustic wave fan-shaped filter and two different piezoelectrically actuated micromechanical resonators are presented to demonstrate the performance of the instrument. With the current detection electronics, the interferometer is capable of detecting out-of-plane surface vibrations up to 2 GHz with a lateral resolution of better than 1 μm and with a minimum detectable vibration amplitude of ∼1 pm.Peer reviewe

Social competence and moderate to vigorous physical activity of school-aged children through a creative physical education intervention

Traditional school physical education focuses on physical skills or strategieswith an expectation that learning these skills lead to healthier lifestyle outsidephysical education classes, while children’s overall moderate to vigorousphysical activity (MVPA) is widely decreasing. Creative Physical Education(CPE) understands physical education more holistically, as the central pedagogical element of movement is social learning. The current study examinedthe development of social competence in school physical education (PE) andtotal moderate to vigorous physical activity (MVPA) participation through aCPE-based intervention. Participants were 363 (177 intervention, 186 control) children from public elementary schools in Central Finland. The datacollection was completed across two measurement points using questionnaires. The key findings were that: 1) the associations between social competence and MVPA engagement were relatively weak and 2) the 12-month intervention was effective in increasing students’ social competence in PE andtotal MVPA engagement. CPE teaching practices could provide positive social experiences in PE. However, applying new strategies into actual schoolsettings may take time, and therefore, children need to be given sufficienttimeframe to take ownership of the activities

Täyssähköauto:rakenne ja toiminta

Tiivistelmä. Tämän kandidaatintyön tavoitteena on käydä läpi täyssähköautojen rakennetta ja toimintaa yleisellä tasolla. Työssä esitellään täyssähköautojen keskeisimpien komponenttien rakenteita ja toimintaperiaatteita. Ensimmäisessä kappaleessa lähdetään liikkeelle sähköautojen historiasta, minkä jälkeen lähdetään perehtymään tarkemmin täyssähköauton keskeisimpiin osiin. Työssä annetaan lukijalle yleiskuva siitä, millaisia eri komponentteja täyssähköauton rakenteessa voidaan käyttää. Voimalinjan osien rakenteiden esittelyn lisäksi käydään läpi osien toimintaperiaatteita. Lopuksi käydään läpi akkujen kierrätystä sekä täyssähköautojen valmistus- ja kunnossapitokustannuksia. Työn tekemisessä hyödynnettiin kirjallisuuslähteitä sekä tutkimusartikkeleita. Tuloksena saatiin laaja yleiskuva täyssähköauton rakenteesta ja toiminnasta

Observation of two elastic thresholds in GeₓAsySe₁ˍₓ ˍy glasses

We have prepared GeₓAsySe1−x−yglasses with mean coordination numbers (MCNs) from 2.2 to 2.86. Tg was found to generally increase with increasing MCN while the glass density showed a maximum at MCN≈2.45 and a minimum at MCN≈2.65. The elastic moduli of the glasses were estimated from the shear and compressional wave velocitiesmeasured by ultrasonic pulse interferometry. For the first time we simultaneously observed two elastictransition thresholds, the first at MCN≈2.45 and the second at MCN≈2.65, which appear closely correlated with changes in the glass microstructure. The elastic moduli of two groups of samples with the same MCN=2.4 and 2.64 but different compositions suggest that the chemical compositions also have an influence on the elastic properties.This research is supported by the Australian Research Council through its Centres of Excellence and Federation Fellow Programs

Drug-Coated Versus Plain Balloon Angioplasty In Arteriovenous Fistulas : A Randomized, Controlled Study With 1-Year Follow-Up (The Drecorest Ii-Study)

Background and Aims: Stenosis due to intimal hyperplasia and restenosis after initially successful percutaneous angioplasty are common reasons for failing arteriovenous fistulas. The aim of this study was to evaluate the effect of drug-coated balloons in the treatment of arteriovenous fistula stenosis. Design: Single-center, parallel group, randomized controlled trial. Block randomized by sealed envelope 1:1. Materials and Methods: A total of 39 patients with primary or recurrent stenosis in a failing native arteriovenous fistulas were randomized to drug-coated balloon (n=19) or standard balloon angioplasty (n=20). Follow-up was 1year. Primary outcome measure was target lesion revascularization. Results: In all, 36 stenoses were analyzed; three patients were excluded due to technical failure after randomization. A total of 88.9% (16/18) in the drug-coated balloon group was revascularized or occluded within 1year, compared to 22.2% (4/18) of the stenoses in the balloon angioplasty group (relative risk for drug-coated balloon 7.09). Mean time-to- target lesion revascularization was 110 and 193days after the drug-coated balloon and balloon angioplasty, respectively (p=0.06). Conclusions: With 1-year follow-up, the target lesion revascularization-free survival after drug-coated balloon-treatment was clearly worse. The reason for this remains unknown, but it may be due to differences in the biological response to paclitaxel in the venous arteriovenous fistula-wall compared to its antiproliferative effect in the arterial wall after drug-coated balloon treatment of atherosclerotic occlusive lesions. Trial registration: ClinicalTrials.gov NCT03036241Peer reviewe