70,906 research outputs found
The effectiveness of origami on overall hand function after injury: A pilot controlled trial
This pilot study measured the effectiveness of using origami to improve the overall hand function of outpatients attending an NHS hand injury unit. The initiative came from one of the authors who had used origami informally in the clinical setting and observed beneficial effects. These observed effects were tested experimentally. The design was a pilot non-randomised controlled trial with 13 participants. Allocation of the seven control group members was based on patient preference. The experimental group members attended a weekly hour of origami for six weeks, in addition to their conventional rehabilitation.
Hand function of all participants was measured using the Jebsen-Taylor Hand Function Test before and after the six-week period, and additional qualitative data were gathered in the form of written evaluations from patients. The quantitative data were analysed using the Mann Whitney U test or Fisherâs exact test. Themes were highlighted from the qualitative data.
The results show that there was a greater difference in the total score of the experimental group using the impaired hand between pre- and post-intervention of 11.8 seconds, compared with 4.3 seconds in the control group, but this was not statistically significant at the 5% level (p=0.06). Additionally, differences in the sub-test scores show a markedly larger improvement in the experimental group. Qualitative data indicate that the experimental group experienced the origami sessions as being enjoyable and beneficial. Further research with a larger sample and randomised group allocation is recommended to verify and expand these preliminary findings
Phonon-Assisted Gain in a Semiconductor Double Quantum Dot Maser
We develop a microscopic model for the recently demonstrated double quantum
dot (DQD) maser. In characterizing the gain of this device we find that, in
addition to the direct stimulated emission of photons, there is a large
contribution from the simultaneous emission of a photon and a phonon, i.e., the
phonon sideband. We show that this phonon-assisted gain typically dominates the
overall gain which leads to masing. Recent experimental data are well fit with
our model.Comment: v1: 6 pgs, 2 figures; v2: 6 pgs, 3 figures, added Fig 2b and Fig. 3b,
modified main text; v3: 6+ pgs, 3 figures, modified main tex
Injection Locking of a Semiconductor Double Quantum Dot Micromaser
Emission linewidth is an important figure of merit for masers and lasers. We
recently demonstrated a semiconductor double quantum dot (DQD) micromaser where
photons are generated through single electron tunneling events. Charge noise
directly couples to the DQD energy levels, resulting in a maser linewidth that
is more than 100 times larger than the Schawlow-Townes prediction. Here we
demonstrate a linewidth narrowing of more than a factor 10 by locking the DQD
emission to a coherent tone that is injected to the input port of the cavity.
We measure the injection locking range as a function of cavity input power and
show that it is in agreement with the Adler equation. The position and
amplitude of distortion sidebands that appear outside of the injection locking
range are quantitatively examined. Our results show that this unconventional
maser, which is impacted by strong charge noise and electron-phonon coupling,
is well described by standard laser models
- âŠ