2,469 research outputs found
Radio Frequency Spectroscopy of Trapped Fermi Gases with Population Imbalance
Motivated by recent experiments, we address, in a fully self consistent
fashion, the behavior and evolution of radio frequency (RF) spectra as
temperature and polarization are varied in population imbalanced Fermi gases.
We discuss a series of scenarios for the experimentally observed zero
temperature pseudogap phase and show how present and future RF experiments may
help in its elucidation. We conclude that the MIT experiments at the lowest
may well reflect ground state properties, but take issue with their claim that
the pairing gap survives up to temperatures of the order of the degeneracy
temperature at unitarity.Comment: 4 page, 3 figures, submitted to PRA Rapi
Use of CD-ROMs in Spanish Libraries
A study was carried out in public, academic, special and government libraries and info rmati on centres in Western Europe during 1989 on the use of CD - ROMs and optical products. Following a brief account of the background to the survey, the paper analyses the results in more depth for libraries and information centres in Spain and compare, theee reeults where relevant with the overall total European response as well as those from individual countriea. lt is evident that optical products in general and CD - ROMs in particular are not yet in widespread use in libraries.Se llevó a cabo un estudio acerca de la utilización del CD-ROM en las bibliotecas públicas, académicas y centros de documentación de los países de Europa Occidental durante 1989. Se analizan con más detenimiento los resultados obtenidos en bibliotecas españolas, comparándolas con el resto de Europa, llegándose a la conclusión de que los productos ópticos en general, y el CD-ROM en particular no se emplean habitualmente en las bibliotecas española
Evolution Of Constructivism
The contrast between social constructivism and cognitive constructivism are depicted in different ways in many studies. The purpose of this paper is to summarize the evolution of constructivism and put a focus on social constructivism from the perception of Vygotsky. This study provides a general idea of the evolution of constructivism for people want to understand this learning theory
Using Drawing As Intervention With Children For In-Service Preschool Teachers
This study provides a basic overview of in-service preschool teachers using drawing as intervention with children. Art therapy is used more often for the smaller children who have more difficulty to describe their emotions and feelings in recognizing words, such as anger, resentment, and different kind of abuses. As a matter of fact, the drawing has become a preferred mode of communication for them. The final result of this study is supporting the said theory. The best predictor of behavioral intention was the in-service teachers’ attitudes while enrolling in the four-month non-credit course in Art Therapy and they believed that this would facilitate their future teaching by much more understanding the children’s behaviors through non-verbal communication and actions. The perceived behavioral control was also the significant predictor of actual application behaviors. This study can provide a valuable reference for those in-service teachers who presently do not have any experience with art as an intervention with children
Direct Large-Area Growth of Graphene on Silicon for Potential Ultra-Low-Friction Applications and Silicon-Based Technologies
Deposition of layers of graphene on silicon has the potential for a wide range of optoelectronic and mechanical applications. However, direct growth of graphene on silicon has been difficult due to the inert, oxidized silicon surfaces. Transferring graphene from metallic growth substrates to silicon is not a good solution either, because most transfer methods involve multiple steps that often lead to polymer residues or degradation of sample quality. Here we report a single-step method for large-area direct growth of continuous horizontal graphene sheets and vertical graphene nano-walls on silicon substrates by plasma-enhanced chemical vapor deposition (PECVD) without active heating. Comprehensive studies utilizing Raman spectroscopy, x-ray/ultraviolet photoelectron spectroscopy (XPS/UPS), atomic force microscopy (AFM), scanning electron microscopy (SEM) and optical transmission are carried out to characterize the quality and properties of these samples. Data gathered by the residual gas analyzer (RGA) during the growth process further provide information about the synthesis mechanism. Additionally, ultra-low friction (with a frictional coefficient ~0.015) on multilayer graphene-covered silicon surface is achieved, which is approaching the superlubricity limit (for frictional coefficients <0.01). Our growth method therefore opens up a new pathway towards scalable and direct integration of graphene into silicon technology for potential applications ranging from structural superlubricity to nanoelectronics, optoelectronics, and even the next-generation lithium-ion batteries
Solving the paradox of the folded falling chain by considering horizontal kinetic energy and link geometry
A folded chain, with one end fixed at the ceiling and the other end released
from the same elevation, is commonly modeled as an energy-conserving system in
one-dimension. However, the analytical paradigms in previous literature is
unsatisfying: The theoretical prediction of the tension at the fixed end
becomes infinitely large when the free end reaches the bottom, contradicting to
the experimental observations. Furthermore, the dependence of the total falling
time on the link number demonstrated in numerical simulations is still
unexplained. Here, considering the horizontal kinetic energy and the geometry
of each link, we derived analytical solutions of the maximal tension as well as
the total falling time, in agreement with simulation results and experimental
data reported in previous studies. This theoretical perspective shows a simple
representation of the complicated two-dimensional falling chain system and, in
particular, specifies the signature of the chain properties.Comment: 13 pages, 4 figure
Dual task measures in older adults with and without cognitive impairment: Response to simultaneous cognitive-exercise training and minimal clinically important difference estimates
BACKGROUND: Responsiveness and minimal clinically important difference (MCID) are critical indices to understand whether observed improvement represents a meaningful improvement after intervention. Although simultaneous cognitive-exercise training (SCET; e.g., performing memory tasks while cycling) has been suggested to enhance the cognitive function of older adults, responsiveness and MCID have not been established. Hence, we aimed to estimate responsiveness and MCIDs of two dual task performance involving cognition and hand function in older adults with and without cognitive impairment and to compare the differences in responsiveness and MCIDs of the two dual task performance between older adults with and without cognitive impairment.
METHODS: A total of 106 older adults completed the Montreal Cognitive Assessment and two dual tasks before and after SCET. One dual task was a combination of Serial Sevens Test and Box and Block Test (BBT), and the other included frequency discrimination and BBT. We used effect size and standardized response mean to indicate responsiveness and used anchor- and distribution-based approaches to estimating MCID ranges. When conducting data analysis, all participants were classified into two cognitive groups, cognitively healthy (Montreal Cognitive Assessment ≥ 26) and cognitively impaired (Montreal Cognitive Assessment \u3c 26) groups, based on the scores of the Montreal Cognitive Assessment before SCET.
RESULTS: In the cognitively healthy group, Serial Seven Test performance when tasked with BBT and BBT performance when tasked with Serial Seven Test were responsive to SCET (effect size = 0.18-0.29; standardized response mean = 0.25-0.37). MCIDs of Serial Seven Test performance when tasked with BBT ranged 2.09-2.36, and MCIDs of BBT performance when tasked with Serial Seven Test ranged 3.77-5.85. In the cognitively impaired group, only frequency discrimination performance when tasked with BBT was responsive to SCET (effect size = 0.37; standardized response mean = 0.47). MCIDs of frequency discrimination performance when tasked with BBT ranged 1.47-2.18, and MCIDs of BBT performance when tasked with frequency discrimination ranged 1.13-7.62.
CONCLUSIONS: Current findings suggest that a change in Serial Seven Test performance when tasked with BBT between 2.09 and 2.36 corrected number (correct responses - incorrect responses) should be considered a meaningful change for older adults who are cognitively healthy, and a change in frequency discrimination performance when tasked with BBT between 1.47 and 2.18 corrected number (correct responses - incorrect responses) should be considered a meaningful change for older adults who are cognitively impaired. Clinical practitioners may use these established MCIDs of dual tasks involving cognition and hand function to interpret changes following SCET for older adults with and without cognitive impairment.
TRIAL REGISTRATION: NCT04689776, 30/12/2020
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