8,254 research outputs found
Preliminary data on boulders at station 6, Apollo 17 landing site
A cluster of boulders at Station 6 (Apollo 17 landing site) consists of breccias derived from the North Massif. Three preliminary lithologic units were established, on the basis of photogeologic interpretations; all lithologies identified photogeologically were sampled. Breccia clasts and matrices studied petrographically and chemically fall into two groups by modal mineralogy: (1) low-K Fra Mauro or high basalt composition, consisting of 50-60% modal feldspar, approximately 45% orthopyroxene and 1-7% Fe-Ti oxide; (2) clasts consisting of highland basalt composition, consisting of 70% feldspar, 30% orthopyroxene and olivine and a trace of Fe-Ti oxide
The reaction from threshold up to 570 MeV
The reaction has been studied in a
kinematically complete measurement with a large acceptance time-of-flight
spectrometer for incident neutron energies between threshold and 570 MeV. The
proton-proton invariant mass distributions show a strong enhancement due to the
pp() final state interaction. A large anisotropy was found in the
pion angular distributions in contrast to the reaction . At small energies, a large forward/backward asymmetry has been
observed. From the measured integrated cross section , the isoscalar cross section has been extracted.
Its energy dependence indicates that mainly partial waves with Sp final states
contribute. Note: Due to a coding error, the differential cross sections as shown in Fig. 9 are too small by a factor of two, and
inn Table 3 the differential cross sections
are too large by a factor of . The integrated cross sections and all
conclusions remain unchanged. A corresponding erratum has been submitted and
accepted by European Physics Journal.Comment: 18 pages, 16 figure
Analysing powers for the reaction and for np elastic scattering from 270 to 570 MeV
The analysing power of the reaction for neutron energies between threshold and 570 MeV has been determined
using a transversely polarised neutron beam at PSI. The reaction has been
studied in a kinematically complete measurement using a time-of-flight
spectrometer with large acceptance. Analysing powers have been determined as a
function of the c.m. pion angle in different regions of the proton-proton
invariant mass. They are compared to other data from the reactions and . The np elastic scattering analysing power was determined as a
by-product of the measurements.Comment: 12 pages, 6 figures, subitted to EPJ-
Evaluation of selected chemical processes for production of low-cost silicon phase 2. silicon material task, low-cost silicon solar array project
Progress from October 1, 1977, through December 31, 1977, is reported in the design of the 50 MT/year experimental facility for the preparation of high purity silicon by the zinc vapor reduction of silicon tetrachloride in a fluidized bed of seed particles to form a free flowing granular product
The Frequency of Active and Quiescent Galaxies with Companions: Implications for the Feeding of the Nucleus
We analyze the idea that nuclear activity, either AGN or star formation, can
be triggered by interactions, studying the percentage of active, HII and
quiescent galaxies with companions. Our sample was selected from the Palomar
survey, and avoids selection biases faced by previous studies. The comparison
between the local galaxy density distributions showed that in most cases there
is no statistically significant difference among galaxies of different activity
types. The comparison of the percentage of galaxies with nearby companions
showed that there is a higher percentage of LINERs, transition, and absorption
line galaxies with companions than Seyferts and HII galaxies. However, we find
that when we consider only galaxies of similar morphological types (ellipticals
or spirals), there is no difference in the percentage of galaxies with
companions among different activity types, indicating that the former result
was due to the morphology-density effect. Also, only small differences are
found when we consider galaxies with similar Halpha luminosities. The
comparison between HII galaxies of different Halpha luminosities shows that
there is a significantly higher percentage of galaxies with companions among
the higher luminosity HII galaxies, indicating that interactions increase the
amount of circumnuclear star formation, in agreement with previous results. The
fact that we find that galaxies of different activity types have the same
percentage of companions, suggests that interactions between galaxies is not a
necessary condition to trigger the nuclear activity in AGNs. We compare our
results with previous ones and discuss their implications. (abridged)Comment: 30 pages, including 6 figures and 3 tables. To appear in The
Astronomical Journal, November issu
[beta]-1,3-Glucanase Is Cryoprotective in Vitro and Is Accumulated in Leaves during Cold Acclimation
Detection of the pairwise kinematic Sunyaev-Zel'dovich effect with BOSS DR11 and the Atacama Cosmology Telescope
We present a new measurement of the kinematic Sunyaev-Zeldovich effect using
data from the Atacama Cosmology Telescope (ACT) and the Baryon Oscillation
Spectroscopic Survey (BOSS). Using 600 square degrees of overlapping sky area,
we evaluate the mean pairwise baryon momentum associated with the positions of
50,000 bright galaxies in the BOSS DR11 Large Scale Structure catalog. A
non-zero signal arises from the large-scale motions of halos containing the
sample galaxies. The data fits an analytical signal model well, with the
optical depth to microwave photon scattering as a free parameter determining
the overall signal amplitude. We estimate the covariance matrix of the mean
pairwise momentum as a function of galaxy separation, using microwave sky
simulations, jackknife evaluation, and bootstrap estimates. The most
conservative simulation-based errors give signal-to-noise estimates between 3.6
and 4.1 for varying galaxy luminosity cuts. We discuss how the other error
determinations can lead to higher signal-to-noise values, and consider the
impact of several possible systematic errors. Estimates of the optical depth
from the average thermal Sunyaev-Zeldovich signal at the sample galaxy
positions are broadly consistent with those obtained from the mean pairwise
momentum signal.Comment: 15 pages, 8 figures, 2 table
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