1,140 research outputs found
On Some Myths about Sequenced Common-valued Auctions
Equilibria are constructed for classes of game models of sequenced second-price auctions having identical common-valued objects. In some of these the equilibrium price falls on average, and in others the seller loses on average by committing to announce publicly something that he knows. Both of these possibilities are surprisesPublicad
Infinite charge mobility in muscovite at 300K
Evidence is presented for infinite charge mobility in natural crystals of
muscovite mica at room temperature. Muscovite has a basic layered structure
containing a flat monatomic sheet of potassium sandwiched between mirror
silicate layers. It is an excellent electrical insulator. Studies of defects in
muscovite crystals indicated that positive charge could propagate over great
distances along atomic chains in the potassium sheets in absence of an applied
electric potential. The charge moved in association with anharmonic lattice
excitations that moved at about sonic speed and created by nuclear recoil of
the radioactive isotope K40. This was verified by measuring currents passing
through crystals when irradiated with energetic alpha particles at room
temperature. The charge propagated more than 1000 times the range of the alpha
particles of average energy and 250 times the range of channelling particles of
maximum energy. The range is limited only by size of the crystal.Comment: 6 pages, 8 figure
Homo- and Heteroleptic Copper(I) Complexes with Diazabutadiene Ligands: Synthesis, Solution- and Solid-State Structural Studies
The preparation of novel copper(I) complexes of diazabutadiene (DAB) ligands with aliphatic backbones is reported. [Cu(DABR)2](BF4), [Cu(DABR)(NCMe)2](BF4) and [CuCl(DABR)] are easily synthesised and air-stable. These complexes, which remain scarce in the literature, have been fully characterised, and their behaviour both in the solid state as well as in solution has been studied by means of X-ray crystallography, NMR and UV/Vis spectroscopy
Quantitative determination of modal content and morphological properties of coal sulphides by digital image analysis as a tool to check their flotation behaviour
An efficient depression of coal sulphides in the flotation process means a healthier environment and may be essential for the sustainability of a coal operation. Nitric and ferric oxidative pre-treatment of coal pyrite have been tested to improve pyrite depression, and the results are compared with those from the process of raw, not pre-treated coal. The removal indexes point to nitric pre-treatment as the best, but depression is still low. The microscopic study of feed and products, coupled to Digital Image Analysis (DIA) in all the cases, provide important clues to understand the behaviour of pyrite, which can be related to quantitative parameters, such as the exposition ratio (ER), and to qualified interpretation of the textures. Pyrite shows in the first float an unexpected hydrophobic behaviour, which is due to its occurrence as framboids, or porous particles which may be intergrown with organic matter and behave as coal. In general, the flotation results can be predicted from the DIA-data, e.g. depression of liberated pyrite into the tailings, increased by oxidative pre-treatments by 300% (ferric) or by > 400% (nitric); or concentration of middlings with lower pyrite ER in the floats. DIA is an efficient tool to obtain some important quantitative informations which otherwise would be inaccessible (e.g. the morphological data on > 1,000,000 pyrite particles for this study), and its use should be enhanced to check ore processing
A generalized least squares estimation method for VARMA models. (Revised edition).
In this paper a new generalized least squares procedure for estimating VARMA models is proposed. This method differs from existing ones in explicitly considering the stochastic structure of the approximation error that arises when lagged innovations are replaced with lagged residuals obtained from a long VAR. Simulation results indicate that this method improves the accuracy of estimates with small and moderate sample sizes, and increases the frequency of identifying small nonzero parameters, with respect to both Double Regression and exact maximum likelihood estimation procedures
On the Unification of Process Semantics: Logical Semantics
We continue with the task of obtaining a unifying view of process semantics
by considering in this case the logical characterization of the semantics. We
start by considering the classic linear time-branching time spectrum developed
by R.J. van Glabbeek. He provided a logical characterization of most of the
semantics in his spectrum but, without following a unique pattern. In this
paper, we present a uniform logical characterization of all the semantics in
the enlarged spectrum. The common structure of the formulas that constitute all
the corresponding logics gives us a much clearer picture of the spectrum,
clarifying the relations between the different semantics, and allows us to
develop generic proofs of some general properties of the semantics.Comment: In Proceedings SOS 2011, arXiv:1108.279
Effect of tannic acid on rumen degradation and intestinal digestion of treated soya bean meals in sheep
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=60689&fulltextType=RA&fileId=S0021859699008151.Previously published as proceeding at the XXIX Jornadas de Estudio AIDA (VII Jornadas sobre Producción Animal) (Zaragoza, Spain, May 20-22, 1997). https://digital.csic.es/handle/10261/15774The current experiment was conducted to study the effect of different doses of tannic acid, a hydrolysable tannin, on ruminal degradation and post-ruminal digestion of treated soya bean meals (SBM) in sheep. Samples of SBM were prepared by spraying 100 g SBM with 100 mi distilled water containing 0, 1, 5, 10, 15 or 25 g of commercial tannic acid (S-0, S-TA1, S-TA2, S-TA3, S-TA4 and S-TA5, respectively). Three ruminally cannulated awes, that had never consumed tannic acid previously, were used to determine in situ degradability of tannic acid-treated SBM. Intestinal digestibility of protein remaining after 16 h rumen incubation was estimated in vitro. Extent of rumen degradation of SBMs was significantly (P < 0.05) affected by the tannic acid treatment. All doses of tannic acid used in this experiment, even the lowest one (S-TA1), significantly decreased the extent of N degradation but only doses higher than that used to treat S-TA3 reduced the extent of DM degradation. This reduction in the extent of DM and N degradation was mainly due to a marked decrease in the immediately degradable fraction (a), which was observed in all treated SBM, and to a lower rate of degradation (c), observed in meals S-TA3, S-TA4 and S-TA5. Intestinal digestion of the non-degraded protein was decreased (P < 0.05) by treatment with the two highest doses of tannic acid (those used to treat meals S-TA4 and S-TA5). It was therefore concluded that tannic acid can exert a negative effect both on rumen degradation and on intestinal digestion of SBM, this effect being clearly dependent on the dose used to treat the SBM.This work
was supported by the Inter-ministerial Commission of
Science and Technology (CICYT) of Spain (Project
AGF98-0874) and the Junta de Castilla y Leon
(Project CSI 7/98).Peer reviewe
Effect of immature oak (Quercus pyrenaica) leaves intake on ruminal fermentation and adaptation of rumen microorganisms in cattle
6 pages, 2 figures.-- Contributed to: VII International Symposium on the Nutrition of Herbivores (Beijing, China, Sep 17−22, 2007).Later published as paper in: Animal Feed Science and Technology 150(1-2): 75-85 (2009), https://digital.csic.es/handle/10261/13289Two experiments were conducted to study the effect of the consumption of different amounts
of immature Pyrenean oak leaves (OL) by beef cattle on in vitro ruminal fermentation and potential
adaptation of rumen microorganisms. A total of twelve ruminally cannulated young Brown Swiss bulls
were divided in experimental groups that received different amounts of OL via the ruminal cannula (on
average 0, 2.5, 5.2 and almost 10 kg fresh matter per animal and day). The gas production technique
was used to study in vitro fermentation of two substrates (grass hay and OL) incubated with rumen
inocula derived from each bull. Results suggest not only a dose-dependent negative effect of tannins
consumption on ruminal fermentation of common feeds (e.g., grass hay), but also an adaptation of
rumen microbial populations from animals receiving moderate amounts of OL. The high level of
tannins in the rumen of bulls that received the highest amount of OL would have exceeded the ability
of microorganisms to tolerate or detoxify them.Supported by the Spanish Ministry of Education and Science, MEC, Project AGL2004-06076-C02-01Peer reviewe
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