The preservation, storage, and handling of black-and-white photographic records

The subject of this article is the preservation of processed blackand- white photographic records in libraries. Since silver gelatin photographic films and papers have been around for about a century, and since by far the largest number of black-and-white photographic images are silver gelatin images, knowledge of the properties of these records is extensive. Factors that may affect their stability are, for the most part, well known.published or submitted for publicatio

Atomic spin squeezing in an optical cavity

We consider squeezing of one component of the collective spin vector of an atomic ensemble inside an optical cavity. The atoms interact with a cavity mode, and the squeezing is obtained by probing the state of the light field that is transmitted through the cavity. Starting from the stochastic master equation, we derive the time evolution of the state of the atoms and the cavity field, and we compute expectation values and variances of the atomic spin components and the quadratures of the cavity mode. The performance of the setup is compared to spin squeezing of atoms by probing of a light field transmitted only once through the sample.Comment: 8 pages, 2 figure

EU Merger Remedies: A Preliminary Empirical Assessment

Mergers that substantially lessen competition are challenged by antitrust authorities. Instead of blocking anticompetitive transitions straight away, authorities might choose to negotiate with the merging parties and allow the transactions to proceed with modifications that restore or preserve the competition in the involved markets. We study a sample of 167 mergers that were under the European Commission’s scrutiny from 1990 to 2002. We use an event study methodology to identify the potential anticompetitive effects of mergers as well as the remedial provisions on these transactions. Stock market reactions around the day of the merger’s announcement provide information on the first question, whereas the stock market reactions around the commission’s final decision day convey information about the outcome of the bargaining process between the authority and the merging parties. We first classify mergers according to their effects on competition and then we develop hypotheses on the effects that remedies are supposed to achieve depending on the merger’s competitive outcome. We isolate several stylized facts. First, we find that remedies were not always appropriately imposed. Second, the market seems to be able to predict remedies’ effectiveness when applied in phase I. Third, the market also seems able to produce a good prior to phase II’s clearances and prohibitions, but not to remedies. This can be due either to a measurement problem or related to the increased merging firms’ bargaining power during the second phase of the merger review

Transport- reaction modeling of marine gas hydrate deposits- global results

We have developed a multi-1D numerical model of gas hydrate formation and dissolution processes in anoxic marine sediments and, by this model, we have estimated the new global gas hydrate inventory (BURWICZ E. B. et al., 2011). The reaction-transport model contains various chemical compounds (solid organic carbon, dissolved methane, inorganic carbon, and sulfates, gas hydrates, and free methane gas). The rates of POC degradation, anaerobic methane oxidation, sulfate reduction, and methanogenesis are kinetically controlled. Gas hydrate stability zone (GHSZ) is defined as a combination of pressure, temperature, and (to a smaller degree) salinity conditions. The lower boundary of the GHSZ is defined as the intersection of gas hydrate and methane gas solubilities. The diffusion equations are solved using a fully-implicit finite-differences method, while all transport processes are resolved by a Semi-Lagrangian scheme. Global input data sets (1°x1° resolution) were compiled from various oceanographic, geological and geophysical sources. The entire model was implemented in Matlab

Portugal and Spain entering the Common Market: Their industrial competitiveness revisited

The purpose of this paper is to assess the overall position as well as the relative strength and weakness of the Iberian manufacturing industries within an enlarged Community. Earlier studies of the authors (Donges, Schatzf 1980; Donges et al., 1982) are up-dated and extended to cover the bilateral trade relations between Portugal and Spain. Following a recapitulation of the major trade patterns of the Iberian countries, we examine the nature of their specialization, both with regard to the EC and among themselves. The increased import competition, employment changes and the adjustment problems faced by the two. countries will be analysed subsequently. The paper concludes with some considerations about an overall strategy to cope with the challenges induced by the accession.

EU Merger Remedies: A Preliminary Empirical Assessment

Mergers that substantially lessen competition are challenged by antitrust authorities. Instead of blocking anticompetitive transitions straight away, authorities might choose to negotiate with the merging parties and allow the transactions to proceed with modifications that restore or preserve the competition in the involved markets. We study a sample of 167 mergers that were under the European Commission’s scrutiny from 1990 to 2002. We use an event study methodology to identify the potential anticompetitive effects of mergers as well as the remedial provisions on these transactions. Stock market reactions around the day of the merger’s announcement provide information on the first question, whereas the stock market reactions around the commission’s final decision day convey information about the outcome of the bargaining process between the authority and the merging parties. We first classify mergers according to their effects on competition and then we develop hypotheses on the effects that remedies are supposed to achieve depending on the merger’s competitive outcome. We isolate several stylized facts. First, we find that remedies were not always appropriately imposed. Second, the market seems to be able to predict remedies’ effectiveness when applied in phase I. Third, the market also seems able to produce a good prior to phase II’s clearances and prohibitions, but not to remedies. This can be due either to a measurement problem or related to the increased merging firms’ bargaining power during the second phase of the merger review.Merger Control; Remedies; European Commission; Event Studies

Deterministic multi-mode photonic device for quantum information processing

We propose the implementation of a light source, which can deterministically generate a rich variety of multi-mode quantum states. The desired states are encoded in the collective population of different ground hyperfine states of an atomic ensemble and converted to multi-mode photonic states by excitation to optically excited levels followed by cooperative spontaneous emission. Among our examples of applications, we demonstrate how two-photon entangled states can be prepared and implemented in a protocol for reference frame free quantum key distribution and how one-dimensional as well as higher-dimensional cluster states can be produced.Comment: 5 pages, 4 figure

Emergence of quasi-one-dimensional physics in Mo3_3S7_7(dmit)3_3, a nearly-isotropic three-dimensional molecular crystal

We report density functional theory calculations for Mo$_3$S$_7$(dmit)$_3$. We derive an ab initio tight-binding model from overlaps of Wannier orbitals; finding a layered model with interlayer hopping terms $\sim3/4$ the size of the in-plane terms. The in-plane Hamiltonian interpolates the kagom\'e and honeycomb lattices. It supports states localized to dodecahedral rings within the plane, which populate one-dimensional (1D) bands and lead to a quasi-1D spin-one model on a layered honeycomb lattice once interactions are included. Two lines of Dirac cones also cross the Fermi energy.Comment: 5 pages, 3 figure