7,980 research outputs found
Probing quasiparticle excitations in a hybrid single electron transistor
We investigate the behavior of quasiparticles in a hybrid electron turnstile
with the aim of improving its performance as a metrological current source. The
device is used to directly probe the density of quasiparticles and monitor
their relaxation into normal metal traps. We compare different trap geometries
and reach quasiparticle densities below 3um^-3 for pumping frequencies of 20
MHz. Our data show that quasiparticles are excited both by the device operation
itself and by the electromagnetic environment of the sample. Our observations
can be modelled on a quantitative level with a sequential tunneling model and a
simple diffusion equation
Desertification
IPCC SPECIAL REPORT ON CLIMATE CHANGE AND LAND (SRCCL)
Chapter 3: Climate Change and Land: An IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystem
Mental health literacy of negative body image: symptom recognition and beliefs about body image in a British community sample
The present study examined mental health literacy of negative body image in a sample of 485 British adults. Participants were presented with vignettes of a fictional woman (âKateâ) and man (âJackâ) suffering from negative body image and were asked questions addressing symptom recognition, distress, sympathy and sources of help-seeking. Participants also completed measures of body appreciation and psychiatric skepticism. Results showed that less than a fifth of participants correctly identified the vignettes as depicting cases of negative body image. The vignette describing Kate was rated as significantly more distressing, deserving of sympathy and requiring help than that of Jack. Women rated the conditions described by both vignettes as significantly more distressing and requiring help than did men. Psychiatric skepticism and body appreciation were significantly associated with beliefs about the vignettes. Implications of the results for the promotion of mental health literacy in relation to body image are discussed
Data on a Laves phase intermetallic matrix composite in situ toughened by ductile precipitates
The data presented in this article are related to the research article entitled âLaves phase intermetallic matrix composite in situ toughened by ductile precipitatesâ (Knowles et al.) [1]. The composite comprised a Fe2(Mo, Ti) matrix with bcc (Mo, Ti) precipitated laths produced in situ by an aging heat treatment, which was shown to confer a toughening effect (Knowles et al.) [1]. Here, details are given on a focused ion beam (FIB) slice and view experiment performed on the composite so as to determine that the 3D morphology of the bcc (Mo, Ti) precipitates were laths rather than needles. Scanning transmission electron microscopy (S(TEM)) micrographs of the microstructure as well as energy dispersive X-ray spectroscopy (EDX) maps are presented that identify the elemental partitioning between the C14 Laves matrix and the bcc laths, with Mo rejected from the matrix into laths. A TEM selected area diffraction pattern (SADP) and key is provided that was used to validate the orientation relation between the matrix and laths identified in (Knowles et al.) [1] along with details of the transformation matrix determined
Mesoporous Strontium-Doped Phosphate-Based Sol-Gel Glasses for Biomedical Applications
Mesoporous phosphate-based glasses have great potential as biomedical materials being able to simultaneously induce tissue regeneration and controlled release of therapeutic molecules. In the present study, a series of mesoporous phosphate-based glasses in the P2O5-CaO-Na2O system doped with 1, 3, and 5 mol % of Sr2+ were prepared using the sol-gel method combined with supramolecular templating. A sample without strontium addition was prepared for comparison. The non-ionic triblock copolymer EO20PO70EO20 (P123) was used as a templating agent. SEM images revealed that all synthesized glasses have an extended porous structure. This was confirmed by N2 adsorption-desorption analysis at 77 K that shows a porosity typical of mesoporous materials. 31P magic angle spinning nuclear magnetic resonance (31P MAS-NMR) and Fourier transform infrared (FTIR) spectroscopies have shown that the glasses are mainly formed by Q1 and Q2 phosphate groups. Degradation of the glasses in deionized water assessed over a 7-day period shows that phosphate, Ca2+, Na+ and Sr2+ ions can be released in a controlled matter over time. In particular, a direct correlation between strontium content and degradation rate was observed. This study shows that Sr-doped mesoporous phosphate-based glasses have great potential in bone tissue regeneration as materials for controlled delivery of therapeutic ions
Muonic hydrogen cascade time and lifetime of the short-lived state
Metastable muonic-hydrogen atoms undergo collisional -quenching,
with rates which depend strongly on whether the kinetic energy is above
or below the energy threshold. Above threshold, collisional
excitation followed by fast radiative
deexcitation is allowed. The corresponding short-lived component
was measured at 0.6 hPa room temperature gas pressure, with
lifetime ns (i.e.,
at liquid-hydrogen density) and population
% (per atom). In
addition, a value of the cascade time, ns, was found.Comment: 4 pages, 3 figure
Dry-mass sensing for microfluidics
We present an approach for interfacing an electromechanical sensor with a microfluidic device for the accurate quantification of the dry mass of analytes within microchannels. We show that depositing solutes onto the active surface of a quartz crystal microbalance by means of an on-chip microfluidic spray nozzle and subsequent solvent removal provides the basis for the real-time determination of dry solute mass. Moreover, this detection scheme does not suffer from the decrease in the sensorâs quality factor and the viscous drag present if the measurement is performed in a liquid environment, yet allows solutions to be analysed. We demonstrate the sensitivity and reliability of our approach by controlled deposition of nanogram levels of salt and protein from a micrometer-sized channel.We thank Alexander K. Buell, Igor Efimov, and Victor Ostanin for valuable discussions on QCM sensors and gratefully acknowledge financial support from the Swiss National Science Foundation (SNF), the Engineering and Physical Sciences Research Council (EPSRC), the Biotechnology and Biological Sciences Research Council (BBSRC), the European Research Council (ERC), as well as the Frances and Augustus Newman Foundation.Permission is granted to quote from an AIP publication with the customary acknowledgment of the source. Republication of an article or portions thereof (e.g., excerpts of greater than 400 words, figures, tables, etc.) in original form or in translation, as well as other types of reuse (such as use in course packs or electronic reserves) require formal permission from AIP and may be subject to fees. Although it is not a legal requirement for permission, as a courtesy, an author of the original article should be informed of any request for republication/reuse
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