166 research outputs found
One – and Two-Step Resonance Energy Transfer Between Cyanine Dyes in Layered Silicates Colloidal Systems
Resonance energy transfer (RET) is of high interest for both the basic research and practical
applications. It is a phenomenon of radiationless transmission of energy between donor and acceptor
molecules. In this study single- and two-step (RET) was investigated between cyanine dye cations (NK1,
NK2, NK3) in colloids of layered silicate, synthetic Sumecton saponite. In these systems the dye molecules
played role of the energy donors (NK1) or energy acceptors (NK2, NK3) or both (NK2). The adsorption and
formation of various types of dye species was studied using visible spectroscopy. The absorption
spectroscopy did not detect any significant molecular aggregation of the dyes at the surface of saponite
particles. The RET process was described by fluorescence spectroscopy. Both the single- and two-step RET
were detected in saponite dispersion. Effects of various parameters on the efficiency of the RET process,
such as dye concentrations, saponite properties the distances between co-adsorbed dye cations were found
to be essential.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3530
A cross-lingual adaptation approach for rapid development of speech recognizers for learning disabled users
Building a voice-operated system for learning disabled users is a difficult task that requires a considerable amount of time and effort. Due to the wide spectrum of disabilities and their different related phonopathies, most approaches available are targeted to a specific pathology. This may improve their accuracy for some users, but makes them unsuitable for others. In this paper, we present a cross-lingual approach to adapt a general-purpose modular speech recognizer for learning disabled people. The main advantage of this approach is that it allows rapid and cost-effective development by taking the already built speech recognition engine and its modules, and utilizing existing resources for standard speech in different languages for the recognition of the users’ atypical voices. Although the recognizers built with the proposed technique obtain lower accuracy rates than those trained for specific pathologies, they can be used by a wide population and developed more rapidly, which makes it possible to design various types of speech-based applications accessible to learning disabled users.This research was supported by the project ‘Favoreciendo la vida autónoma de discapacitados intelectuales con problemas de comunicación oral mediante interfaces personalizados de reconocimiento automático del habla’, financed by the Centre of Initiatives for Development Cooperation (Centro de Iniciativas de Cooperación al Desarrollo, CICODE), University of Granada, Spain. This research was supported by the Student Grant Scheme 2014 (SGS) at the Technical University of Liberec
Hubble and Spitzer Observations of an Edge-on Circumstellar Disk around a Brown Dwarf
We present observations of a circumstellar disk that is inclined close to
edge-on around a young brown dwarf in the Taurus star-forming region. Using
data obtained with SpeX at the NASA Infrared Telescope Facility, we find that
the slope of the 0.8-2.5 um spectrum of the brown dwarf 2MASS J04381486+2611399
cannot be reproduced with a photosphere reddened by normal extinction. Instead,
the slope is consistent with scattered light, indicating that circumstellar
material is occulting the brown dwarf. By combining the SpeX data with mid-IR
photometry and spectroscopy from the Spitzer Space Telescope and previously
published millimeter data from Scholz and coworkers, we construct the spectral
energy distribution for 2MASS J04381486+2611399 and model it in terms of a
young brown dwarf surrounded by an irradiated accretion disk. The presence of
both silicate absorption at 10 um and silicate emission at 11 um constrains the
inclination of the disk to be ~70 deg, i.e. ~20 deg from edge-on. Additional
evidence of the high inclination of this disk is provided by our detection of
asymmetric bipolar extended emission surrounding 2MASS J04381486+2611399 in
high-resolution optical images obtained with the Hubble Space Telescope.
According to our modeling for the SED and images of this system, the disk
contains a large inner hole that is indicative of a transition disk (R_in~58
R_star~0.275 AU) and is somewhat larger than expected from embryo ejection
models (R_out=20-40 AU vs. R_out<10-20 AU).Comment: The Astrophysical Journal, in pres
An open-label trial of tomoxetine in pediatric attention deficit hyperactivity disorder.
OBJECTIVE: To collect pilot data assessing the safety, tolerability, and efficacy of tomoxetine, a nonstimulant norepinephrine enhancer, in pediatric attention deficit hyperactivity disorder (ADHD).
METHODS: An open-label trial of tomoxetine in pediatric ADHD was conducted as part of a multisite clinical trial. Following a baseline assessment, an ascending dose titration was completed during 10 weekly visits.
RESULTS: Ten subjects were enrolled at baseline, with eight completing the study. Seven of the eight remaining subjects met efficacy criteria. Significant decreases in symptom severity ratings by parents and study investigators were found. The medication was well tolerated, with transient appetite suppression the most frequently reported side effect. However, subjects\u27 weights remained stable across study visits.
DISCUSSION: These preliminary findings suggest that tomoxetine may hold promise as a treatment for pediatric ADHD
Field Assessment of Energy Audit Tools for Retrofit Programs
This project focused on the use of home energy ratings as a tool to promote energy retrofits in existing homes. A home energy rating provides a quantitative appraisal of a home's asset performance, usually compared to a benchmark such as the average energy use of similar homes in the same region. Home rating systems can help motivate homeowners in several ways. Ratings can clearly communicate a home's achievable energy efficiency potential, provide a quantitative assessment of energy savings after retrofits are completed, and show homeowners how they rate compared to their neighbors, thus creating an incentive to conform to a social standard. An important consideration is how rating tools for the retrofit market will integrate with existing home energy service programs. For residential programs that target energy savings only, home visits should be focused on key efficiency measures for that home. In order to gain wide adoption, a rating tool must be easily integrated into the field process, demonstrate consistency and reasonable accuracy to earn the trust of home energy technicians, and have a low monetary cost and time hurdle for homeowners. Along with the Home Energy Score, this project also evaluated the energy modeling performance of SIMPLE and REM/Rate
The unusual hydrocarbon emission from the early carbon star HD 100764: The connection between aromatics and aliphatics
We have used the Infrared Spectrograph (IRS) on the Spitzer Space Telescope
to obtain spectra of HD 100764, an apparently single carbon star with a
circumstellar disk. The spectrum shows emission features from polycyclic
aromatic hydrocarbons (PAHs) that are shifted to longer wavelengths than
normally seen, as characteristic of ``class C'' systems in the classification
scheme of Peeters et al. All seven of the known class C PAH sources are
illuminated by radiation fields that are cooler than those which typically
excite PAH emission features. The observed wavelength shifts are consistent
with hydrocarbon mixtures containing both aromatic and aliphatic bonds. We
propose that the class C PAH spectra are distinctive because the carbonaceous
material has not been subjected to a strong ultraviolet radiation field,
allowing relatively fragile aliphatic materials to survive.Comment: 11 pages (in emulateapj), 5 tables, 7 figures. Accepted for
publication in Ap
Spitzer Infrared Spectrograph survey of young stars in the Chamaeleon I star-forming region
We present 5 to 36 micron mid-infrared spectra of 82 young stars in the ~2
Myr old Chamaeleon I star-forming region, obtained with the Spitzer Infrared
Spectrograph (IRS). We have classified these objects into various evolutionary
classes based on their spectral energy distributions and the spectral features
seen in the IRS spectra. We have analyzed the mid-IR spectra of Class II
objects in Chamaeleon I in detail, in order to study the vertical and radial
structure of the protoplanetary disks surrounding these stars. We find evidence
for substantial dust settling in most protoplanetary disks in Chamaeleon I. We
have identified several disks with altered radial structures in Chamaeleon I,
among them transitional disk candidates which have holes or gaps in their
disks. Analysis of the silicate emission features in the IRS spectra of Class
II objects in Chamaeleon I shows that the dust grains in these disks have
undergone significant processing (grain growth and crystallization). However,
disks with radial holes/gaps appear to have relatively unprocessed grains. We
further find the crystalline dust content in the inner (< 1-2 AU) and the
intermediate (< 10 AU) regions of the protoplanetary disks to be tightly
correlated. We also investigate the effects of accretion and stellar
multiplicity on the disk structure and dust properties. Finally, we compare the
observed properties of protoplanetary disks in Cha I with those in slightly
younger Taurus and Ophiuchus regions and discuss the effects of disk evolution
in the first 1-2 Myr.Comment: 80 pages, 32 Figures, Accepted for publication in the Astrophysical
Journal Supplement Serie
- …