4,839 research outputs found
Preparation and tensile properties of guar gum hydrogel films
Guar gum hydrogels may be dried to form polymer films which have the potential for use as biodegradable alternatives to polymers such as low-density polyethylene. In this study, the tensile strength and tensile modulus of guar gel films having moisture contents ranging between 15% and 18% (wet basis) were measured at a strain rate of 1 mm minâ»Âč. Mean tensile strengths of the films ranged between 25 MPa and 40 MPa (dependent on composition) which is of similar magnitude to the tensile strength data for polyethylene and cellophane that are reported in the literature. The mean tensile modulus of the films (1.5â2.5 GPa) was higher than the tensile modulus values reported for low-density polyethylene but comparable to those for cellophane (3 GPa)
Atomic and Molecular Data for Optical Stellar Spectroscopy
High-precision spectroscopy of large stellar samples plays a crucial role for
several topical issues in astrophysics. Examples include studying the chemical
structure and evolution of the Milky Way galaxy, tracing the origin of chemical
elements, and characterizing planetary host stars. Data are accumulating from
instruments that obtain high-quality spectra of stars in the ultraviolet,
optical and infrared wavelength regions on a routine basis. These instruments
are located at ground-based 2- to 10-m class telescopes around the world, in
addition to the spectrographs with unique capabilities available at the Hubble
Space Telescope. The interpretation of these spectra requires high-quality
transition data for numerous species, in particular neutral and singly ionized
atoms, and di- or triatomic molecules. We rely heavily on the continuous
efforts of laboratory astrophysics groups that produce and improve the relevant
experimental and theoretical atomic and molecular data. The compilation of the
best available data is facilitated by databases and electronic infrastructures
such as the NIST Atomic Spectra Database, the VALD database, or the Virtual
Atomic and Molecular Data Centre (VAMDC). We illustrate the current status of
atomic data for optical stellar spectra with the example of the Gaia-ESO Public
Spectroscopic Survey. Data sources for 35 chemical elements were reviewed in an
effort to construct a line list for a homogeneous abundance analysis of up to
100000 stars.Comment: Published 30 April 2015 in Physica Script
A paradox of syntactic priming: why response tendencies show priming for passives, and response latencies show priming for actives
Speakers tend to repeat syntactic structures across sentences, a phenomenon called syntactic priming. Although it has been suggested that repeating syntactic structures should result in speeded responses, previous research has focused on effects in response tendencies. We investigated syntactic priming effects simultaneously in response tendencies and response latencies for active and passive transitive sentences in a picture description task. In Experiment 1, there were priming effects in response tendencies for passives and in response latencies for actives. However, when participants' pre-existing preference for actives was altered in Experiment 2, syntactic priming occurred for both actives and passives in response tendencies as well as in response latencies. This is the first investigation of the effects of structure frequency on both response tendencies and latencies in syntactic priming. We discuss the implications of these data for current theories of syntactic processing
Spitzer Observations of Low Luminosity Isolated and Low Surface Brightness Galaxies
We examine the infrared properties of five low surface brightness galaxies
(LSBGs) and compare them with related but higher surface brightness galaxies,
using Spitzer Space Telescope images and spectra. All the LSBGs are detected in
the 3.6 and 4.5um bands, representing the stellar population. All but one are
detected at 5.8 and 8.0um, revealing emission from hot dust and aromatic
molecules, though many are faint or point-like at these wavelengths. Detections
of LSBGs at the far-infrared wavelengths, 24, 70, and 160um, are varied in
morphology and brightness, with only two detections at 160um, resulting in
highly varied spectral energy distributions. Consistent with previous
expectations for these galaxies, we find that detectable dust components exist
for only some LSBGs, with the strength of dust emission dependent on the
existence of bright star forming regions. However, the far-infrared emission
may be relatively weak compared with normal star-forming galaxies.Comment: 20 pages, 8 figures, accepted to Ap
Electron-nucleus scattering in the NEUT event generator
The NEUT event generator is a widely-used tool to simulate neutrino
interactions for energies between 10s of MeV and a few TeV. NEUT plays a
crucial role in neutrino oscillation analyses for the T2K and Hyper-K
experiments, providing the primary simulation of the neutrino interactions
whose final-state products are measured to infer the oscillation parameters.
NEUT is also capable of simulating nucleon decay and hadron scattering. These
proceedings present an expansion of NEUT to simulate electron scattering before
showing comparisons to experimental measurements and using discrepancies to
derive an empirical correction to NEUT's treatment of nuclear removal energy.Comment: 5 pages, 3 figures. NuFact2022 proceedings submissio
Ontologies, Mental Disorders and Prototypes
As it emerged from philosophical analyses and cognitive research, most concepts exhibit typicality effects, and resist to the efforts of defining them in terms of necessary and sufficient conditions. This holds also in the case of many medical concepts. This is a problem for the design of computer science ontologies, since knowledge representation formalisms commonly adopted in this field do not allow for the representation of concepts in terms of typical traits. However, the need of representing concepts in terms of typical traits concerns almost every domain of real world knowledge, including medical domains. In particular, in this article we take into account the domain of mental disorders, starting from the DSM-5 descriptions of some specific mental disorders. On this respect, we favor a hybrid approach to the representation of psychiatric concepts, in which ontology oriented formalisms are combined to a geometric representation of knowledge based on conceptual spaces
- âŠ