34,839 research outputs found

    Effects of different cultivation techniques on vineyard fauna

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    Green covering compared to soil cultivation enhanced the number of individuals of Araneae living on or near soil. No differences between the different soil management systems were found for the number of individuals of Staphylinidae and Carabidae. The typical main species of the two systems were different for all groups analyzed (Araneae, Staphylinidae and Carabidae)

    Dense cores in the dark cloud complex LDN1188

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    We present a molecular line emission study of the LDN1188 dark cloud complex located in Cepheus. In this work we focused on the densest parts of the cloud and on the close neighbourhood of infrared point sources. We made ammonia mapping with the Effelsberg 100-m radio telescope and identified 3 dense cores. CS(1--0), CS(2--1) and HCO+^{+}(1--0) measurements performed with the Onsala 20\,m telescope revealed the distribution of dense molecular material. The molecular line measurements were supplemented by mapping the dust emission at 1.2\,mm in some selected directions using the IRAM 30\,m telescope. With these data we could work out a likely evolutionary sequence in this dark clould complex.Comment: YouResAstro2012 conference presentation; accepted to Astronomishen Nachrichten (25-July-2013

    Superposition as memory: unlocking quantum automatic complexity

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    Imagine a lock with two states, "locked" and "unlocked", which may be manipulated using two operations, called 0 and 1. Moreover, the only way to (with certainty) unlock using four operations is to do them in the sequence 0011, i.e., 0n1n0^n1^n where n=2n=2. In this scenario one might think that the lock needs to be in certain further states after each operation, so that there is some memory of what has been done so far. Here we show that this memory can be entirely encoded in superpositions of the two basic states "locked" and "unlocked", where, as dictated by quantum mechanics, the operations are given by unitary matrices. Moreover, we show using the Jordan--Schur lemma that a similar lock is not possible for n=60n=60. We define the semi-classical quantum automatic complexity Qs(x)Q_{s}(x) of a word xx as the infimum in lexicographic order of those pairs of nonnegative integers (n,q)(n,q) such that there is a subgroup GG of the projective unitary group PU(n)(n) with Gq|G|\le q and with U0,U1GU_0,U_1\in G such that, in terms of a standard basis {ek}\{e_k\} and with Uz=kUz(k)U_z=\prod_k U_{z(k)}, we have Uxe1=e2U_x e_1=e_2 and Uye1e2U_y e_1 \ne e_2 for all yxy\ne x with y=x|y|=|x|. We show that QsQ_s is unbounded and not constant for strings of a given length. In particular, Qs(0212)(2,12)<(3,1)Qs(060160) Q_{s}(0^21^2)\le (2,12) < (3,1) \le Q_{s}(0^{60}1^{60}) and Qs(0120)(2,121)Q_s(0^{120})\le (2,121).Comment: Lecture Notes in Computer Science, UCNC (Unconventional Computation and Natural Computation) 201

    Effect of high hydrostatic pressure treatments on volatiles of berry purées

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    High hydrostatic pressure (HHP) technology, as a promising alternative of thermal-treatment and chemical preservatives, can be used to produce minimally processed foods. It has the advantage of affecting only non-covalent bonds of macromolecules in foods, and thus preserves nutritional components, taste, and flavour exceptionally well. However, HHP also influences enzymatic reactions of food. Although some of these changes are often beneficial, monitoring the potential effects of high pressure treatments — especially in the field of product and technology development — is essential. The aim of this study was to point out some parameters of high hydrostatic pressure technique (pressure, temperature, build-up time, holding time, number of cycles) that can substantially impact the sensory properties of treated products

    The 3rd Flow Component as a QGP Signal

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    Earlier fluid dynamical calculations with QGP show a softening of the directed flow while with hadronic matter this effect is absent. On the other hand, we indicated that a third flow component shows up in the reaction plane as an enhanced emission, which is orthogonal to the directed flow. This is not shadowed by the deflected projectile and target, and shows up at measurable rapidities, ycm=12y_cm = 1-2. To study the formation of this effect initial stages of relativistic heavy ion collisions are studied. An effective string rope model is presented for heavy ion collisions at RHIC energies. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field. The typical field strength (string tension) for RHIC energies is about 5-12 GeV/fm, what allows us to talk about "string ropes". The results show that QGP forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. The produced initial state can be used as an initial condition for further hydrodynamical calculations. Such initial conditions lead to the creation of third flow component. Recent v1v_1 measurements are promising that this effect can be used as a diagnostic tool of the QGP

    Spectrum and Thermodynamics of the one-dimensional supersymmetric t-J model with 1/r21/r^2 exchange and hopping

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    We derive the spectrum and the thermodynamics of the one-dimensional supersymmetric t-J model with long range hopping and spin exchange using a set of maximal-spin eigenstates. This spectrum confirms the recent conjecture that the asymptotic Bethe-ansatz spectrum is exact. By empirical determining the spinon degeneracies of each state, we are able to explicitly construct the free energy.Comment: 13 pages, Latex, (published in PRB46, 6639 (1992)

    The initial state of ultra-relativistic heavy ion collision

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    A model for energy, pressure and flow velocity distributions at the beginning of ultra-relativistic heavy ion collisions is presented, which can be used as an initial condition for hydrodynamic calculations. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field, produced in the collision. The typical field strength (string tension) for RHIC energies is about 5-12 GeV/fm, what allows us to talk about "string ropes". The results show that a QGP forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. Such initial conditions may lead to the creation of "antiflow" or "third flow component".Comment: 28 pages, 9 figures. The presentation has been changed considerably. Some parts of the model have been reformulated, what led to modifications in several equations: (20-38), Apps. A, B. All the figures have been changed from 100 GeV/nucl initial energy to the achieved RHIC energy of 65 GeV/nucl. The last subplots in the Figs. 3, 4, 5, 6 present E=T^{00} in the laboratory frame now, instead of the energy density in the local rest frame, e, shown in the initial version. We also added the App. C to clarify the transformation from space-time to lightcone coordinates and bac
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