239 research outputs found
Forms and exchangeability of inorganic phosphate in composted solid organic wastes
Switzerland yearly produces more than 260,000 Mg of compost, two thirds of which is recycled in agriculture and horticulture. This research was undertaken to examine the forms and availability of inorganic P (Pi) in Swiss composts made from solid kitchen and garden wastes using the isotopic exchange kinetic technique, a sequential Pi extraction and magic angle spinning (MAS) solid-state 31P nuclear magnetic resonance (NMR) spectroscopy. The different approaches described in this paper demonstrate the presence of a complex mixture of Pi species in the studied composts. Isotopic exchange experiments and sequential extraction showed that these composts contained relatively large concentrations of rapidly available Pi. Significant correlations were observed between the concentration of water-soluble Pi (Cp), and the total N, C and P content of composts suggesting that organic substances partly controlled the amount of rapidly available Pi. Significant correlations were observed in alkaline composts between the amount of Pi which can not be exchanged within 3 months and the total P and Ca content. In alkaline composts solid-state MAS 31P NMR results suggested the presence of a range of slightly soluble and poorly crystallized Ca-P compounds such as apatites or octacalcium phosphates and of organic P compounds. The slowly or non-exchangeable Pi present in these composts could therefore be bound to Ca in the form of apatites or octacalcium phosphate
Evidence of joint commitment in great apes’ natural joint actions
Human joint action seems special, as it is grounded in joint commitment—a sense of mutual obligation participants feel towards each other. Comparative research with humans and non-human great apes has typically investigated joint commitment by experimentally interrupting joint actions to study subjects’ resumption strategies. However, such experimental interruptions are human-induced, and thus the question remains of how great apes naturally handle interruptions. Here, we focus on naturally occurring interruptions of joint actions, grooming and play, in bonobos and chimpanzees. Similar to humans, both species frequently resumed interrupted joint actions (and the previous behaviours, like grooming the same body part region or playing the same play type) with their previous partners and at the previous location. Yet, the probability of resumption attempts was unaffected by social bonds or rank. Our data suggest that great apes experience something akin to joint commitment, for which we discuss possible evolutionary origins
Flavor SU(3) breaking effects in the chiral unitary model for meson-baryon scatterings
We examine flavor SU(3) breaking effects on meson-baryon scattering
amplitudes in the chiral unitary model. It turns out that the SU(3) breaking,
which appears in the leading quark mass term in the chiral expansion, can not
explain the channel dependence of the subtraction parameters of the model,
which are crucial to reproduce the observed scattering amplitudes and resonance
properties.Comment: RevTeX4, 4 pages, 3 figures, 2 table
Chiral dynamics of p-wave in K^- p and coupled states
We perform an evaluation of the p-wave amplitudes of meson-baryon scattering
in the strangeness S=-1 sector starting from the lowest order chiral
Lagrangians and introducing explicitly the Sigma^* field with couplings to the
meson-baryon states obtained using SU(6) symmetry. The N/D method of
unitarization is used, equivalent, in practice, to the use of the
Bethe-Salpeter equation with a cut-off. The procedure leaves no freedom for the
p-waves once the s-waves are fixed and thus one obtains genuine predictions for
the p-wave scattering amplitudes, which are in good agreement with experimental
results for differential cross sections, as well as for the width and partial
decay widths of the Sigma^*(1385).Comment: LaTeX, 18 pages, 6 figure
Baryon polarization in low-energy unpolarized meson-baryon scattering
We compute the polarization of the final-state baryon, in its rest frame, in
low-energy meson--baryon scattering with unpolarized initial state, in
Unitarized BChPT. Free parameters are determined by fitting total and
differential cross-section data (and spin-asymmetry or polarization data if
available) for , and scattering. We also compare our
results with those of leading-order BChPT
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Utility of the US National Ignition Facility for Development of Inertial Fusion Energy
The demonstration of inertial fusion ignition and gain in the proposed US National Ignition Facility (NIF), along with the parallel demonstration of the feasibility of an efficient, high-repetition-rate driver, would provide the basis for a follow-on Engineering Test Facility (ETF), a facility for integrated testing of the technologies needed for inertial fusion-energy (IFE) power plants. A workshop was convened at the University of California, Berkeley on February 22--24, 1994, attended by 61 participants from 17 US organizations, to identify possible NIF experiments relevant to IFE. We considered experiments in four IFE areas: Target physics, target chamber dynamics, fusion power ethnology, and target systems, as defined in the following sections
An airdrop that preserves recipient privacy
A common approach to bootstrapping a new cryptocurrency is an airdrop,
an arrangement in which existing users give away currency to entice
new users to join. But current airdrops offer no recipient privacy:
they leak which recipients have claimed the funds, and this information
is easily linked to off-chain identities.
In this work, we address this issue by defining a private airdrop and
describing concrete schemes for widely-used user credentials, such
as those based on ECDSA and RSA. Our private airdrop for RSA builds
upon a new zero-knowledge argument of knowledge of the factorization
of a committed secret integer, which may be of independent interest.
We also design a private genesis airdrop that efficiently sends private
airdrops to millions of users at once. Finally, we implement and
evaluate. Our fastest implementation takes 40--180 ms to generate
and 3.7--10 ms to verify an RSA private airdrop signature. Signatures
are 1.8--3.3 kiB depending on the security parameter
Politics, resistance and patronage: the African boycott of the 1966 World Cup and its ramifications
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