18,007 research outputs found
ROSAT Detection and High Precision Localization of X-ray Sources in the November 19, 1978 Gamma-Ray Burst Error Box
We report on observations of the 1978, November 19 Gamma-Ray Burst source,
performed with the ROSAT X-ray HRI experiment. Two sources were detected, one
of which is possibly variable. The latter source is identical to the source
discovered in 1981 by the EINSTEIN satellite, and recently detected by ASCA.
The precise localization of these sources is given, and our data are compared
with optical, radio and previous X-ray data.Comment: 10 pages with 2 figures, Accepted for publication in the
Astrophysical Journal (Letters), Latex, aastex macros neede
Assessing parental risk in parenting plan (child custody) evaluation cases involving internet sexual behavior
One type of claim in parenting assessment (child custody)1 cases is that one parent, typically the father, is alleged to be engaging in improper or compulsive sexual behavior via the Internet. The sexual behavior at issue can range from frequent sexually explicit chats with other adults to compulsive viewing of adult pornography. In more extreme cases, the problematic behavior may involve viewing child pornography, and in some cases the parent faces actual criminal charges in this regard. The present article reviews the current scientific knowledge base for evaluation of risk in such parenting evaluation cases and provides some guidelines and recommendations for an evaluator in the assessment process
Trajectory Deflection of Spinning Magnetic Microparticles, the Magnus Effect at the Microscale
The deflection due to the Magnus force of magnetic particles with a diameter
of 80 micrometer dropping through fluids and rotating in a magnetic field was
measured. With Reynolds number for this experiment around 1, we found
trajectory deflections of the order of 1 degree, in agreement within
measurement error with theory. This method holds promise for the sorting and
analysis of the distribution in magnetic moment and particle diameter of
suspensions of microparticles, such as applied in catalysis, or objects loaded
with magnetic particles.Comment: 12 pages, 3 figures. Appendix with 6 figure
Beheersing intrinsieke kwaliteit potplanten met als pilot Ficus en Anthurium : deelproject 3
Ontwikkelen van een meettechniek waarmee de intrinsieke kwaliteit van potplanten tijdens de teelt gemeten kan worden. Uit deelproject 2 blijkt dat symptomen van lichtstress in een vroeg stadium met MIPS gemeten kunnen worden bij zowel Ficus als Anthurium. Van belang is om na te gaan of al voordat uitwendige chlorose zichtbaar is aan het gewas, afwijkingen worden geconstateerd in de fotosynthese-efficiënte middels de metingen van de MIPS, zodat daarop geanticipeerd kan worden door de teler
Duration of Regrowth of Ryegrass (\u3ci\u3eLolium perenne\u3c/i\u3e) Swards: Effects on Rumen Fermentation of Lactating Dairy Cows
The relative importance of duration of sward regrowth and rumen fill and fermentation on the control of grazing time and intake rate during the first grazing session of the day were studied. Four lactating dairy cows were allowed to graze ryegrass (Lolium perenne) swards, with five different regrowth periods after mowing (6, 9, 16, 22 and 30 d). The cows were allowed to graze until they stopped voluntarily. Samples of rumen liquid were taken at approximately 0, 30, 60, 120 and 240 min after the grazing session was finished. Concentration of volatile fatty acids (VFA) followed a significant quadratic trend with a maximum concentration observed at approximately 110 min after cessation of grazing. In this study, rumen fill, VFA (either total or major components) and ammonia concentration as individual variables were not correlated with grazing time or dry matter intake
Infrared Quasi Fixed Points and Mass Predictions in the MSSM II: Large tan(beta) Scenario
We consider the infrared quasi fixed point solutions of the renormalization
group equations for the Yukawa couplings and soft supersymmetry breaking
parameters in the MSSM in the \underline{large } regime. The
existence of IR quasi fixed points together with the values of gauge couplings,
third generation quarks, lepton and Z-boson masses allows one to predict masses
of the Higgs bosons and SUSY particles as functions of the only free parameter,
, or the gluino mass. The lightest Higgs boson mass for TeV is found to be GeV for and
GeV for .Comment: 15 pages, LateX file with 4 eps figures, corrected numbers, new
column in table, last versio
Further search for a neutral boson with a mass around 9 MeV/c2
Two dedicated experiments on internal pair conversion (IPC) of isoscalar M1
transitions were carried out in order to test a 9 MeV/c2 X-boson scenario. In
the 7Li(p,e+e-)8Be reaction at 1.1 MeV proton energy to the predominantly T=0
level at 18.15 MeV, a significant deviation from IPC was observed at large pair
correlation angles. In the 11B(d,n e+e-)12C reaction at 1.6 MeV, leading to the
12.71 MeV 1+ level with pure T=0 character, an anomaly was observed at 9
MeV/c2. The compatibility of the results with the scenario is discussed.Comment: 12 pages, 5 figures, 2 table
d_c=4 is the upper critical dimension for the Bak-Sneppen model
Numerical results are presented indicating d_c=4 as the upper critical
dimension for the Bak-Sneppen evolution model. This finding agrees with
previous theoretical arguments, but contradicts a recent Letter [Phys. Rev.
Lett. 80, 5746-5749 (1998)] that placed d_c as high as d=8. In particular, we
find that avalanches are compact for all dimensions d<=4, and are fractal for
d>4. Under those conditions, scaling arguments predict a d_c=4, where
hyperscaling relations hold for d<=4. Other properties of avalanches, studied
for 1<=d<=6, corroborate this result. To this end, an improved numerical
algorithm is presented that is based on the equivalent branching process.Comment: 4 pages, RevTex4, as to appear in Phys. Rev. Lett., related papers
available at http://userwww.service.emory.edu/~sboettc
Fully broadband vAPP coronagraphs enabling polarimetric high contrast imaging
We present designs for fully achromatic vector Apodizing Phase Plate (vAPP)
coronagraphs, that implement low polarization leakage solutions and achromatic
beam-splitting, enabling observations in broadband filters. The vAPP is a pupil
plane optic, inducing the phase through the inherently achromatic geometric
phase. We discuss various implementations of the broadband vAPP and set
requirements on all the components of the broadband vAPP coronagraph to ensure
that the leakage terms do not limit a raw contrast of 1E-5. Furthermore, we
discuss superachromatic QWPs based of liquid crystals or quartz/MgF2
combinations, and several polarizer choices. As the implementation of the
(broadband) vAPP coronagraph is fully based on polarization techniques, it can
easily be extended to furnish polarimetry by adding another QWP before the
coronagraph optic, which further enhances the contrast between the star and a
polarized companion in reflected light. We outline several polarimetric vAPP
system designs that could be easily implemented in existing instruments, e.g.
SPHERE and SCExAO.Comment: 11 pages, 5 figures, presented at SPIE Astronomical Telescopes and
Instrumentation 201
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