1,134 research outputs found
Distraction from pain and executive functioning: an experimental investigation of the role of inhibition, task switching and working memory
Although many studies have investigated the effectiveness of distraction as a method of pain control, the cognitive processes by which attentional re-direction is achieved, remain unclear. In this study the role of executive functioning abilities (inhibition, task switching and working memory) in the effectiveness of distraction is investigated. We hypothesized that the effectiveness of distraction in terms of pain reduction would be larger in participants with better executive functioning abilities. Ninety-one undergraduate students first performed executive functioning tasks, and subsequently participated in a cold pressor task (CPT). Participants were randomly assigned to (1) a distraction group, in which an attention-demanding tone-detection task was performed during the CPT, or (2) a control group, in which no distraction task was performed. Participants in the distraction group reported significantly less pain during the CPT, but the pain experience was not influenced by executive functioning abilities. However, the performance on the distraction task improved with better inhibition abilities, indicating that inhibition abilities might be important in focussing on a task despite the pain
Capillary origami of micro-machined micro-objects: Bi-layer conductive hinges
Recently, we demonstrated controllable 3D self-folding by means of capillary
forces of silicon-nitride micro-objects made of rigid plates connected to each
other by flexible hinges [1]. In this paper, we introduce platinum electrodes
running from the substrate to the plates over these bendable hinges. The
fabrication yield is as high as (77 +/- 2) % for hinges with a length less than
75 {\mu}m. The yield reduces to (18 +/- 2) % when the length increases above
100 {\mu}m. Most of the failures in conductivity are due to degradation of the
platinum/chromium layer stack during the final plasma cleaning step. The
bi-layer hinges survive the capillary folding process, even for extremely small
bending radii of 5 {\mu}m, nor does the bending have any impact on the
conductivity. Stress in the different layers deforms the hinges, which does not
affect the conductivity. Once assembled, the conductive hinges can withstand a
current density of (1.6 +/- 0.4) A/cm . This introduction of
conductive electrodes to elastocapillary self-folded silicon-based
micro-objects extends the range of their possible applications by allowing an
electronic functionality of the folded parts.Comment: Currently on a peer review process. 13 page
Elastocapillary folding using stop-programmable hinges fabricated by 3D micro-machining
We show elasto-capillary folding of silicon nitride objects with accurate
folding angles between flaps of 70.60.1{\deg} and demonstrate the
feasibility of such accurate micro-assembly with a final folding angle of
90{\deg}. The folding angle is defined by stop-programmable hinges that are
fabricated starting from silicon molds employing accurate three-dimensional
corner lithography. This nano-patterning method exploits the conformal
deposition and the subsequent timed isotropic etching of a thin film in a 3D
shaped silicon template. The technique leaves a residue of the thin film in
sharp concave corners which can be used as an inversion mask in subsequent
steps. Hinges designed to stop the folding at 70.6{\deg} were fabricated
batchwise by machining the V-grooves obtained by KOH etching in (110) silicon
wafers; 90{\deg} stop-programmable hinges were obtained starting from silicon
molds obtained by dry etching on (100) wafers. The presented technique is
applicable to any folding angle and opens a new route towards creating
structures with increased complexity, which will ultimately lead to a novel
method for device fabrication.Comment: Submitted to a peer reviewed journa
Isotopic and velocity distributions of Bi produced in charge-pickup reactions of 208Pb at 1 A GeV
Isotopically resolved cross sections and velocity distributions have been
measured in charge-pickup reactions of 1 A GeV 208Pb with proton, deuterium and
titanium target. The total and partial charge-pickup cross sections in the
reactions 208Pb + 1H and 208Pb + 2H are measured to be the same in the limits
of the error bars. A weak increase in the total charge-pickup cross section is
seen in the reaction of 208Pb with the titanium target. The measured velocity
distributions show different contributions - quasi-elastic scattering and
Delta-resonance excitation - to the charge-pickup production. Data on total and
partial charge-pickup cross sections from these three reactions are compared
with other existing data and also with model calculations based on the coupling
of different intra-nuclear cascade codes and an evaporation code.Comment: 20 pages, 12 figures, background information on
http://www-w2k.gsi.de/kschmidt
Bricolage as Survival, Growth and Transformation:the Role of Patchworking in the Social Agency of Migrant Entrepreneurs
This article examines the patch-working strategies of migrant entrepreneurs as a form of social agency. âPatch-workingâ â the reliance on supplementary forms of income to support business activity â is often seen as a means of cushioning the financial vulnerability of small firms. However, the mechanisms and forms that patch-working takes tend to be overlooked. Evidence from 42 West Midlandsâ firms shows that, despite the highly constrained operating environment, the exercise of social agency can help to cushion against disadvantage and to rework their current conditions through patch-working. This allows for business growth, and even transformational growth in some cases, rather than sheer survival. Even so, our findings show that the agency of migrant entrepreneurs brings about only minor improvements in revenue and is certainly not capable of fundamentally changing either the nature of the sector or the structure of the labour market in which they are embedded
Cross-sections of spallation residues produced in 1.A GeV 208Pb on proton reactions
Spallation residues produced in 1 GeV per nucleon Pb on proton
reactions have been studied using the FRagment Separator facility at GSI.
Isotopic produc- tion cross-sections of elements from Pm to Pb
have been measured down to 0.1 mb with a high accuracy. The recoil kinetic
energies of the produced fragments were also determined. The obtained
cross-sections agree with most of the few existing gamma-spectroscopy data.
Data are compared with different intra nuclear-cascade and evaporation-fission
models. Drastic deviations were found for a standard code used in technical
applications.Comment: 4 pages, 3 figures, accepted for publication in Phys. Rev. Lett.
Revised version May 12, 200
Transition from participant to spectator fragmentation in Au+Au reaction between 60 AMeV and 150 AMeV
Using the quantum molecular dynamics approach, we analyze the results of the
recent INDRA Au+Au experiments at GSI in the energy range between 60 AMeV and
150 AMeV. It turns out that in this energy region the transition toward a
participant-spectator scenario takes place. The large Au+Au system displays in
the simulations as in the experiment simultaneously dynamical and statistical
behavior which we analyze in detail: The composition of fragments close to
midrapidity follows statistical laws and the system shows bi-modality, i.e. a
sudden transition between different fragmentation pattern as a function of the
centrality as expected for a phase transition. The fragment spectra at small
and large rapidities, on the other hand, are determined by dynamics and the
system as a whole does not come to equilibrium, an observation which is
confirmed by FOPI experiments for the same system.Comment: published versio
Properties of projectile-fragments in the Ar + Al reaction at 44 A MeV. Comparison with a multisequential decay model
GANIL-EXPResults on projectile fragmentâfragment coincidences in the forward direction and for the reaction 40Ar + 27Al at 44 A MeV are presented and compared with the predictions of two different entrance channel models, a two-body and a three-body mechanism both followed by a binary multisequential decay including fission. This analysis shows that many features of the projectile decay products are well accounted for by the binary multisequential decay model. However the results depend critically upon the initial masses and excitation energies of the primary projectile fragments. In this respect, the three-body approach underestimates the excitation energy imparted to the primary fragments whereas the two-body scenario overestimates it. The present data put strong constraints on the initial excitation energy imparted to the primary fragments which appears to be intermediate between the predictions of the two models
Measurement of nuclide cross-sections of spallation residues in 1 A GeV 238U + proton collisions
The production of heavy nuclides from the spallation-evaporation reaction of
238U induced by 1 GeV protons was studied in inverse kinematics. The
evaporation residues from tungsten to uranium were identified in-flight in mass
and atomic number. Their production cross-sections and their momentum
distributions were determined. The data are compared with empirical
systematics. A comparison with previous results from the spallation of 208Pb
and 197Au reveals the strong influence of fission in the spallation of 238U.Comment: 20 pages, 10 figures, background information at
http://www-wnt.gsi.de/kschmidt
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