1,154 research outputs found
Time-Entanglement Between Mind and Matter
This contribution explores Wolfgang Pauli's idea that mind and matter are complementary aspects of the same reality. We adopt the working hypothesis that there is an undivided timeless primordial reality (the primordial "one world''). Breaking its symmetry, we obtain a contextual description of the holistic reality in terms of two categorically different domains, one tensed and the other tenseless. The tensed domain includes, in addition to tensed time, nonmaterial processes and mental events. The tenseless domain refers to matter and physical energy. This concept implies that mind cannot be reduced to matter, and that matter cannot be reduced to mind. The non-Boolean logical framework of modern quantum theory is general enough to implement this idea. Time is not taken to be an a priori concept, but an archetypal acausal order is assumed which can be represented by a one-parameter group of automorphisms, generating a time operator which parametrizes all processes, whether material or nonmaterial. The time-reversal symmetry is broken in the nonmaterial domain, resulting in a universal direction of time for the material domain as well
Pregalactic LiBeB Production by Supernova Cosmic Rays
I calculate the evolution of Be and B abundances produced by cosmic rays
generated by massive stars in the pregalactic phase of the universe. The inputs
for calculation, i.e. the star formation rate and the nuclear abundances of
cosmic rays, which I assume to be the same as those of the ISM, are taken from
the results of a detailed cosmic chemical evolution model with its parameters
best fitted from several items of observational information including an early
reionization of the IGM by . I found that when the Li plateau
abundance observed in metal-poor halo stars originated in the pregalactic
cosmological cosmic ray nucleosynthesis, Be and B simultaneously produced with
Li amount to the lowest levels ever detected in metal-poor halo stars. It
is desirable to observe Be and B abundances in metal-poor halo stars with
[Fe/H] in order to elucidate the possibility of early LiBeB
production by pregalactic supernova cosmic ray nucleosynthesis.Comment: 13 pages, 8 figures, ApJ accepte
Big Bang Nucleosynthesis with long-lived strongly interacting relic particles
We study effects of relic long-lived strongly interacting massive particles
(X particles) on big bang nucleosynthesis (BBN). The X particle is assumed to
have existed during the BBN epoch, but decayed long before detected. The
interaction strength between an X and a nucleon is assumed to be similar to
that between nucleons. Rates of nuclear reactions and beta decay of X-nuclei
are calculated, and the BBN in the presence of neutral charged X^0 particles is
calculated taking account of captures of X^0 by nuclei. As a result, the X^0
particles form bound states with normal nuclei during a relatively early epoch
of BBN leading to the production of heavy elements. Constraints on the
abundance of X^0 are derived from observations of primordial light element
abundances. Particle models which predict long-lived colored particles with
lifetimes longer than about 200 s are rejected. This scenario prefers the
production of 9Be and 10B. There might, therefore, remain a signature of the X
particle on primordial abundances of those elements. Possible signatures left
on light element abundances expected in four different models are summarized.Comment: 6 pages, 2 figures, to appear in the Proceedings of IAU Symposium
268: Light elements in the Universe (C. Charbonnel, M. Tosi, F. Primas, C.
Chiappini, eds.; Cambridge Univ. Press
Boron Abundances in the Galactic Disk
When compared to lithium and beryllium, the absence of boron lines in the
optical results in a relatively small data set of boron abundances measured in
Galactic stars to date. In this paper we discuss boron abundances published in
the literature and focus on the evolution of boron in the Galaxy as measured
from pristine boron abundances in cool stars as well as early-type stars in the
Galactic disk. The trend of B with Fe obtained from cool F-G dwarfs in the disk
is found to have a slope of 0.87 +/- 0.08 (in a log-log plot). This slope is
similar to the slope of B with Fe found for the metal poor halo stars and there
seems to be a smooth connection between the halo and disk in the chemical
evolution of boron. The disk trend of boron with oxygen has a steeper slope of
~1.5. This slope suggests an intermediate behavior between primary and
secondary production of boron with respect to oxygen. The slope derived for
oxygen is consistent with the slope obtained for Fe provided that [O/Fe]
increases as [Fe/H] decreases, as observed in the disk.Comment: 6 pages, 3 figures, IAUS268 Proceeding
Li and Be depletion in metal-poor subgiants
Original article can be found at: http://www.aanda.org/--Copyright The European Southern Observatory (ESO) DOI : 10.1051/0004-6361:20053182Peer reviewe
Stellar Abundances in Giant Stars in the Metal-Rich Globular Cluster NGC6528
We present the first results of a detailed abundance analysis, based on VLT
observations, of giant stars in the very metal-rich globular cluster NGC 6528.
We will be able to tie the horizontal branch abundances (see e.g. Carretta et
al. 2001) to those of the more luminous giants (see CMDs). For the very similar
cluster NGC 6553 studies of different types of stars have yielded very
disparate results. Our first analysis of three of our stars seem to indicate
that indeed the different sorts of stars do show similar abundances if one
homogeneous set of models and parameters are being used.Comment: 2 pages, 2 diagrams, to be published in the proceedings of "New
Horizons in Globular Cluster Astronomy" held in Padua 2002, eds. Piotto,
Meylan, Djorgovsk
Cosmic Ray production of Beryllium and Boron at high redshift
Recently, new observations of Li6 in Pop II stars of the galactic halo have
shown a surprisingly high abundance of this isotope, about a thousand times
higher than its predicted primordial value. In previous papers, a cosmological
model for the cosmic ray-induced production of this isotope in the IGM has been
developed to explain the observed abundance at low metallicity. In this paper,
given this constraint on the Li6, we calculate the non-thermal evolution with
redshift of D, Be, and B in the IGM. In addition to cosmological cosmic ray
interactions in the IGM, we include additional processes driven by SN
explosions: neutrino spallation and a low energy component in the structures
ejected by outflows to the IGM. We take into account CNO CRs impinging on the
intergalactic gas. Although subdominant in the galactic disk, this process is
shown to produce the bulk of Be and B in the IGM, due to the differential metal
enrichment between structures (where CRs originate) and the IGM. We also
consider the resulting extragalactic gamma-ray background which we find to be
well below existing data. The computation is performed in the framework of
hierarchical structure formation considering several star formation histories
including Pop III stars. We find that D production is negligible and that a
potentially detectable Be and B plateau is produced by these processes at the
time of the formation of the Galaxy (z ~ 3).Comment: 9 pages, 7 figure
Power supply conditioning circuit
A power supply conditioning circuit that can reduce Periodic and Random Deviations (PARD) on the output voltages of dc power supplies to -150 dBV from dc to several KHz with no measurable periodic deviations is described. The PARD for a typical commercial low noise power supply is -74 dBV for frequencies above 20 Hz and is often much worse at frequencies below 20 Hz. The power supply conditioning circuit described here relies on the large differences in the dynamic impedances of a constant current diode and a zener diode to establish a dc voltage with low PARD. Power supplies with low PARD are especially important in circuitry involving ultrastable frequencies for the Deep Space Network
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