2,261 research outputs found
HRTS observations of the fine structure and dynamics of the solar chromosphere and transition zone
Arc-second UV observations of the Sun by the NRL High Resolution Telescope and Spectrograph (HRTS) have led to the discovery of dynamic fine structures such as 400 km/s coronal jets and chromospheric jets (spicules) and have provided new information about the structure and dynamics of the transition zone. These observations are reviewed and their relevance to the origin of the solar wind is discussed
Source Regions of Coronal Mass Ejections
Observations of the solar corona with the Large Angle Spectrometric
Coronograph (LASCO) and Extreme ultraviolet Imaging Telescope (EIT) instruments
on the Solar and Heliospheric Observatory (SOHO) provide an unprecedented
opportunity to study coronal mass ejections (CMEs) from their initiation
through their evolution out to 30 \rsun. The objective of this study is to gain
an understanding of the source regions from which the CMEs emanate. To this
end, we have developed a list of 32 CMEs whose source regions are located on
the solar disk and are well observed in EIT 195 {\AA} data during the period
from so lar minimum in January 1996 through the rising part of the cycle in May
1998. We compare the EIT source regions with photospheric magnetograms from the
Michelson Doppler Imager (MDI) instrument on SOHO and the NSO/Kitt Peak
Observatory and also with H data from various sources. The overall
results of our study show that 41% of the CME related transients observed are
associated with active regions and have no prominence eruptions, 44% are
associated with eruptions of prominences embedded in active regions and 15% are
associated with eruptions of prominences outside active regions. Those CMEs
that do not involve prominence eruptions originate in active regions both with
and without prominences. We describe 6 especially well observed events. These
case studies suggest that active region CMEs (without eruptive prominences) are
associated with active regions with lifetimes between 11--80 days. They are
also often associated with small scale emerging or cancelling flux over
timescales of 6--7 hours. CMEs associated with active region prominence
eruptions, on the other hand, are typically associated with old active regions
with lifetimes 6-7 months.Comment: Accepted for publication in ApJ, scheduled for Nov 1, 2001 issu
Shock waves in thermal lensing
We review experimental investigation on spatial shock waves formed by the
self-defocusing action of a laser beam propagation in a disordered thermal
nonlinear media.Comment: 9 pages, 12 figure
The Nature of Stellar Winds in the Star-Disk Interaction
Stellar winds may be important for angular momentum transport from accreting
T Tauri stars, but the nature of these winds is still not well-constrained. We
present some simulation results for hypothetical, hot (~1e6 K) coronal winds
from T Tauri stars, and we calculate the expected emission properties. For the
high mass loss rates required to solve the angular momentum problem, we find
that the radiative losses will be much greater than can be powered by the
accretion process. We place an upper limit to the mass loss rate from
accretion-powered coronal winds of ~1e-11 solar masses per year. We conclude
that accretion powered stellar winds are still a promising scenario for solving
the stellar angular momentum problem, but the winds must be cool (~1e4 K) and
thus are not driven by thermal pressure.Comment: 7 pages, including 2 figures. To appear in proceedings of IAU
Symposium No. 243: Star-Disk Interaction in Young Star
Bernoulli type polynomials on Umbral Algebra
The aim of this paper is to investigate generating functions for modification
of the Milne-Thomson's polynomials, which are related to the Bernoulli
polynomials and the Hermite polynomials. By applying the Umbral algebra to
these generating functions, we provide to deriving identities for these
polynomials
ANALYZING SOCIAL PLAY AND SOCIAL INTERACTION OF A CHILD WITH AUTISM SPECTRUM DISORDER IN THE INCLUSIVE KINDERGARTEN EDUCATION
The benefits of social play and social interactions have been accepted for children with special needs attending inclusive kindergarten education. This study aims to examine social play and social interaction of a child with autism spectrum disorder in the inclusive kindergarten education. Social play observation form, social interaction observation form, activity adaptation form and parent interview was employed for data collection. Case study was conducted and the sample of this study included one special needed child with ASD. Free play times of the child was video recorded, activity adaptations were reviewed, and an interview with the mother was conducted. The data was analyzed using descriptive analyses technique. The research findings indicated that the child with ASD in an inclusive kindergarten education has limited number of social play and social interactions. Even though these limited social play and social interactions, they had an important impact on the social behavior of the child with ASD. Inclusive classroom teachers and researchers would get benefit for their teaching skills using this study results. Article visualizations
Bayh-Dole Act, Supreme Court of the United States Decision in Stanford v. Roche, and Public Health
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