Liquidity Crises and Corporate Cash Holdings in Chile

This paper addresses the way optimal cash holdings decisions may be affected in episodes of adverse liquidity shocks. Motivated by the recent financial crisis, we are particularly interested in understanding how firm characteristics can explain differences in the adjustment speed to desired cash holdings, and how these characteristics determine whether a firm is more or less affected during a liquidity crisis. To address those issues, we use a large panel dataset with quarterly information of Chilean firms during the period 1996 through 2009. In line with some previous empirical evidence, our findings show that leverage, banking debt, liquid assets, size and volatility affect cash holdings. We also find that liquidity crises have had an overall negative and economically significant effect on the firms’ cash holdings and this effect varies across firm size. In addition, our results reveal other important component of heterogeneity across firms: we find that medium-sized firms are less capable of adjusting cash holdings than do small and large firms.

Comparison of the heat transfer efficiency of nanofluids

The continuously increasing power involved in many applications, coupled with the very small size of a number of component devices, is pushing the technical community to look for more efficient heat transfer systems, to remove the heat generated and keep the system under controlled operating conditions. In particular, significant interest has been devoted to the use of the so-called nanofluids, obtained by suspending nano-sized particles in conventional heat transfer liquids. According to some literature, these suspensions present enhanced heat transfer capabilities, without the inconveniencies of particles settlement and clogging of the channels encountered using larger particles. However, other results show that the actual improvement in the heat transfer efficiency may depend on the adopted working conditions and on the reference parameters (fluid velocity, Reynolds number, pressure drop, etc.) assumed to compare the performances of the nanoparticles suspensions with those of the clear thermal fluid. In the present work heat transfer experiments were carried out on a number of nanofluids systems, varying the type and the concentration of the nanoparticles, and the fluid dynamic regime. The investigated suspensions gave rise to heat transfer coefficients different from those of their respective clear thermal fluid, the thermal efficiency being higher or lower, depending on the fluid dynamic parameter used as a base for comparing the systems. Generally speaking, in most cases nanofluids may give an advantage from the heat transfer point of view only when the conditions are unfavorable for the traditional thermal fluid

The CHAIN-REDS Semantic Search Engine

e-Infrastructures, and in particular Data Repositories and Open Access Data Infrastructures, are essential platforms for e-Science and e-Research and are being built since several years both in Europe and the rest of the world to support diverse multi/inter-disciplinary Virtual Research Communities. So far, however, it is difficult for scientists to correlate papers to datasets used to produce them and to discover data and documents in an easy way. In this paper, the CHAINREDS project’s Knowledge Base and its Semantic Search Engine are presented, which attempt to address those drawbacks and contribute to the reproducibility of science

Direct Measurement of Competing Quantum Effects on the Kinetic Energy of Heavy Water upon Melting

Even at room temperature, quantum mechanics plays a major role in determining the quantitative behaviour of light nuclei, changing significantly the values of physical properties such as the heat capacity. However, other observables appear to be only weakly affected by nuclear quantum effects (NQEs): for instance, the melting temperatures of light and heavy water differ by less than 4 K. Recent theoretical work has attributed this to a competition between intra and inter molecular NQEs, which can be separated by computing the anisotropy of the quantum kinetic energy tensor. The principal values of this tensor change in opposite directions when ice melts, leading to a very small net quantum mechanical effect on the melting point. This paper presents the first direct experimental observation of this phenomenon, achieved by measuring the deuterium momentum distributions n(p) in heavy water and ice using Deep Inelastic Neutron Scattering (DINS), and resolving their anisotropy. Results from the experiments, supplemented by a theoretical analysis, show that the anisotropy of the quantum kinetic energy tensor can also be captured for heavier atoms such as oxygen

Hydrogen mean force and anharmonicity in polycrystalline and amorphous ice

The hydrogen mean force from experimental neutron Compton profiles is derived using deep inelastic neutron scattering on amorphous and polycrystalline ice. The formalism of mean force is extended to probe its sensitivity to anharmonicity in the hydrogen-nucleus effective potential. The shape of the mean force for amorphous and polycrystalline ice is primarily determined by the anisotropy of the underlying quasi-harmonic effective potential. The data from amorphous ice show an additional curvature reflecting the more pronounced anharmonicity of the effective potential with respect to that of ice Ih.Comment: 12 pages, 7 figures, original researc

4He adsorbed in cylindrical silica nanopores: Effect of size on the single-atom mean kinetic energy

This paper reports a study of the short-time dynamics of helium confined in silica nanopores (xerogel powder), with average pore diameters of 24 and 160 Å. The longitudinal momentum distribution of helium adsorbed in xerogels has been determined via deep inelastic neutron scattering (DINS) measurements performed on the VESUVIO spectrometer at the ISIS spallation source. DINS measurements, in the attosecond time scale, (i.e., 10−16–10−15 s), were performed at a temperature of T=2.5 K and saturated vapor pressure conditions, with 95% pore volume filling. The average wave-vector transfer q was about 130 Å−1. For confined helium, significant changes in the values of the single-particle mean kinetic energies ⟨EK⟩ are found in the bulk phase. These are 32.6±8.7 K for the 24 Å and 24.4±5.3 K for the 160 Å pore diameters, remarkably higher than ⟨EK⟩=16.2±0.4 K, the value of normal liquid 4He at T=2.5 K and saturated vapor pressure conditions. The results are interpreted in terms of a model where 4He atoms are arranged in concentric annuli along the cylindrical pore axis, with ⟨EK⟩ mainly dependent on the ratio between the atomic “effective” diameter and the pore diameter. The number of solid layers close to pore surface is found to be strongly pore-size dependent with one single solid layer for 24 Å diameter pore and three solid layers for 160 Å diameter pore

Experimental evaluation of heat transfer coefficient for nanofluids

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The paper reports the results of heat transfer experimental tests on nanofluids. Measurements were performed in a two-loop test rig for immediate comparison of the thermal performances of the nanofluid with the base-fluid. The convective heat transfer was evaluated in a circular pipe heated with uniform heat flux and with flow regimes from laminar to turbulent. Tests have been performed to compare the heat transfer capability of nanofluids and water at the same velocity or Reynolds number , and they have been compared with values calculated from widely used correlations. In particular ten different nanofluids and three base fluids (in addition to the water) have been used. The analysis of the experimental data shows a different behavior depending on the parameter used in the comparison, and, as a consequence, the addition of nanoparticles to the heat transfer fluid can result advantageous or not, depending on the specific point of view. Furthermore some classical correlations have been used to estimate the heat transfer coefficients, and the analysis shows that they are able to provide good agreement with the experimental data both for the nanofluid and water

Characterization of CRISPR-Cas Systems in Serratia marcescens Isolated from Rhynchophorus ferrugineus (Olivier, 1790) (Coleoptera: Curculionidae)

The CRISPR-Cas adaptive immune system has been attracting increasing scientific interest for biological functions and biotechnological applications. Data on the Serratia marcescens system are scarce. Here, we report a comprehensive characterisation of CRISPR-Cas systems identified in S. marcescens strains isolated as secondary symbionts of Rhynchophorus ferrugineus, also known as Red Palm Weevil (RPW), one of the most invasive pests of major cultivated palms. Whole genome sequencing was performed on four strains (S1, S5, S8, and S13), which were isolated from the reproductive apparatus of RPWs. Subtypes I-F and I-E were harboured by S5 and S8, respectively. No CRISPR-Cas system was detected in Si or S13. Two CRISPR arrays (4 and 51 spacers) were detected in S5 and three arrays (11, 31, and 30 spacers) were detected in S8. The CRISPR-Cas systems were located in the genomic region spanning from ybhR to phnP, as if this were the only region where CRISPR-Cas loci were acquired. This was confirmed by analyzing the S. marcescens complete genomes available in the NCBI database. This region defines a genomic hotspot for horizontally acquired genes and/or CRISPR-Cas systems. This study also supplies the first identification of subtype I-E in S. marcescens

Landscape Economic Value for Territorial Scenarios of Change: An Application for the Unesco Site of Langhe, Roero and Monferrato

The present paper focuses on the issues related to the economic value of landscape and the role of indicators and indices systems. The aim of the study is the definition of a synthetic index of Landscape Economic Value (LEV) through a system of economic indicators, to measure the attractiveness of Vineyard Landscape of Langhe-Roero and Monferrato (IT), recently included in the UNESCO World Heritage List (2014). Furthermore, the synthetic index is employed in a dynamic transformation model that works in a cluster system of municipalities, where the Landscape Economic Value acts as an attractor factor generating people flows. The results obtained by the evaluation model might be an innovative proposal to define development territorial scenarios in decisional making-processe