839 research outputs found
Relaxation timescales and decay of correlations in a long-range interacting quantum simulator
We study the time evolution of correlation functions in long-range
interacting quantum Ising models. For a large class of initial conditions,
exact analytic results are obtained in arbitrary lattice dimension, both for
ferromagnetic and antiferromagnetic coupling, and hence also in the presence of
geometric frustration. In contrast to the nearest-neighbour case, we find that
correlations decay like stretched or compressed exponentials in time. Provided
the long-range character of the interactions is sufficiently strong, pronounced
prethermalization plateaus are observed and relaxation timescales are widely
separated. Specializing to a triangular lattice in two spatial dimensions, we
propose to utilize these results for benchmarking of a recently developed
ion-trap based quantum simulator.Comment: 19 pages, 6 figures; v2: one section removed, appendices added; v3:
upper bound corrected + minor corrections; v4: as publishe
Patients' and parents' experiences during wound care of epidermolysis bullosa from a dyadic perspective:a survey study
Background Epidermolysis bullosa is a rare, often severe, genetic disorder characterized by fragility of the skin and mucous membranes. Despite the important role of parents during wound care, an essential factor in adapting to this disease, studies focusing on the parent-child relationship during wound care are scarce. The current study is aimed at addressing this gap. Methods A quantitative study among 31 children (n = 2
The relationship between quality of life and coping strategies of children with EB and their parents
BackgroundEpidermolysis bullosa (EB) is a group of rare genetic skin disorders that primarily manifest as blisters and erosions following mild mechanical trauma. Despite the crucial role of the parents of children with EB in managing the disease, studies focusing on the parent-child relationship remain a gap in the literature. To address this gap, the current quantitative study, involving 55 children with all types of EB and 48 parents, assessed the relationship between their quality of life and coping strategies. Quality of life was measured with the Pediatric Quality of Life Inventory and TNO-AZL Questionnaire for Adult's Health- related Quality of Life, and coping strategies were assessed with the Coping with a Disease Questionnaire. The majority of the analyses were descriptive and the results were interpreted qualitatively because of the small sample size.ResultsOverall, the quality of life of children with EB and that of their parents was somewhat lower compared with the quality of life of healthy children and adults. Children with EB who more frequently used emotional reactions and cognitive-palliative strategies to cope with the disease demonstrated lower levels of emotional and social functioning, while children who showed more acceptance and distancing showed higher levels of functioning on all domains. Parents who frequently demonstrated emotional reactions reported lower levels of social functioning and experienced more depressive emotions and anger. Parents who used more avoidance showed higher levels of positive emotions. Within parent-child dyads, acceptance, cognitive-palliative strategies and distancing were positively related. Children's emotional and social functioning were negatively associated with their parents' depressive emotions. Parents' acceptance was linked to higher physical functioning in children, whereas children's avoidance was linked to a lower level of anger in parents.ConclusionChildren who are able to accept the disease or distance themselves from it appear to be better off in contrast to those who tend to engage in the cognitive-palliative strategies and expressing emotional reactions. Parents seem to be better off when they are able to use avoidance in contrast to those who tend to show emotional reactions. Further research is needed to substantiate these findings
Pembuatan dan Pengembangan Account E-Commerce pada “Waroeng Bali Tani”
Perkembangan teknologi informasi di Indonesia mengalami peningkatan di setiap harinya. Tentu saja perkembangan positif ini dapat kita manfaatkan untuk membantu masyarakat sekitar kita, seperti melakukan perdagangan tanpa perlu bertatap muka, terlebih di masa pandemi Covid-19 ini dampak teknologi sangatlah besar. Dimana UMKM pastinya mengalami penurunan omset penjualan, dikarenakan menurunnya intensitas pembeli yang datang karena tidak berani keluar rumah, sekarang konsumen cenderung membeli segala sesuatu menggunakan e-commerce. Kegiatan pengabdian masyarakat ini kami lakukan untuk memberikan media penjualan secara online melalui e-commerce berupa account Shopee dan cara pengembangannya kepada Waroeng Bali Tani yang merupakan UMKM produk pertanian. Pengabdian ini menggunakan metode Participatory Action Research (PAR), dengan terlibat secara langsung dalam penggalian informasi yang dibutuhkan oleh narasumber. Berdasarkan metode PAR, kami mengambil 3 tahapan metode dalam pengabdian ini yakni metode pendekatan, metode pengenalan, dan metode pengembangan. Hasil dari pengabdian adalah berupa account e-commerce dan pelatihan pengembangan account tersebut, agar nantinya UMKM ini dapat berkembang dengan adanya bantuan teknologi
Multi Mode Interferometer for Guided Matter Waves
We describe the fundamental features of an interferometer for guided matter
waves based on Y-beam splitters and show that, in a quasi two-dimensional
regime, such a device exhibits high contrast fringes even in a multi mode
regime and fed from a thermal source.Comment: Final version (accepted to PRL
Beroepsmatige blootstelling aan ozon in een drinkwaterproductiebedrijf
Gemeten blootstellingsniveaus aan ozon laten dusdanig lage waarden zien, dat onder normale omstandigheden een kans op normoverschrijding niet aanwezig i
Electron and Hole Spin Splitting and Photogalvanic Effect in Quantum Wells
A theory of the circular photogalvanic effect caused by spin splitting in
quantum wells is developed. Direct interband transitions between the hole and
electron size-quantized subbands are considered. It is shown that the
photocurrent value and direction depend strongly on the form of the spin-orbit
interaction. The currents induced by structure-, bulk-, and interface-inversion
asymmetry are investigated. The photocurrent excitation spectra caused by spin
splittings in both conduction and valence bands are calculated.Comment: 7 pages, 3 figure
Soft Color Interactions and Diffractive Hard Scattering at the Fermilab Tevatron
An improved understanding of nonperturbative QCD can be obtained by the
recently developed soft color interaction models. Their essence is the
variation of color string-field topologies, giving a unified description of
final states in high energy interactions, e.g., diffractive and nondiffractive
events in ep and ppbar. Here we present a detailed study of such models (the
soft color interaction model and the generalized area law model) applied to
ppbar, considering also the general problem of the underlying event including
beam particle remnants. With models tuned to HERA ep data, we find a good
description also of Tevatron data on production of W, beauty and jets in
diffractive events defined either by leading antiprotons or by one or two
rapidity gaps in the forward or backward regions. We also give predictions for
diffractive J/psi production where the soft exchange mechanism produces both a
gap and a color singlet ccbar state in the same event. This soft color
interaction approach is also compared with Pomeron-based models for
diffraction, and some possibilities to experimentally discriminate between
these different approaches are discussed.Comment: 35 pages, 15 figures, uses REVTeX. Minor changes, version to appear
in Phys. Rev.
Intrinsic electrochemical activity of single walled carbon nanotube–Nafion assemblies
The intrinsic electrochemical properties and activity of single walled carbon nanotube (SWNT) network electrodes modified by a drop-cast Nafion film have been determined using the one electron oxidation of ferrocene trimethyl ammonium (FcTMA+) as a model redox probe in the Nafion film. Facilitated by the very low transport coefficient of FcTMA+ in Nafion (apparent diffusion coefficient of 1.8 × 10−10 cm2 s−1), SWNTs in the 2-D network behave as individual elements, at short (practical) times, each with their own characteristic diffusion, independent of neighbouring sites, and the response is diagnostic of the proportion of SWNTs active in the composite. Data are analysed using candidate models for cases where: (i) electron transfer events only occur at discrete sites along the sidewall (with a defect density typical of chemical vapour deposition SWNTs); (ii) all of the SWNTs in a network are active. The first case predicts currents that are much smaller than seen experimentally, indicating that significant portions of SWNTs are active in the SWNT–Nafion composite. However, the predictions for a fully active SWNT result in higher currents than seen experimentally, indicating that a fraction of SWNTs are not connected and/or that not all SWNTs are wetted completely by the Nafion film to provide full access of the redox mediator to the SWNT surface
Differential Production Cross Section of Z Bosons as a Function of Transverse Momentum at sqrt{s}=1.8 TeV
We present a measurement of the transverse momentum distribution of Z bosons
produced in ppbar collisions at sqrt{s}=1.8 TeV using data collected by the D0
experiment at the Fermilab Tevatron Collider during 1994--1996. We find good
agreement between our data and a current resummation calculation. We also use
our data to extract values of the non-perturbative parameters for a particular
version of the resummation formalism, obtaining significantly more precise
values than previous determinations.Comment: 10 pages, 2 figures, submitted to Phys. Rev. Letters v2 has margin
error correcte
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