A study of flow conditions near the substratum in an experimental channel [Translation from: Verhandlungen der Internationalen Vereinigung fur Theoretische und Angewandte Limnologie 18, 718-725, 1972]

In a slow flow, on a smooth uniform substratum, a limited bed allows the existence of currents slow enough for benthic invertebrates. These conditions rarely occur naturally. The investigations carried out in this work aimed, on an intermediary scale, to define the influence of irregularities in the substratum on flow near the bottom. The substrata used were made of glass marbles. The investigations were carried out in a transparent channel of 70 cm in length and a rectangular section 10 x 5 cm. The data was analysed to study the general evolution of flow in terms of average speeds and the appearance of the turbulence near the bottom

Tailoring strain in SrTiO3 compound by low energy He+ irradiation

The ability to generate a change of the lattice parameter in a near-surface layer of a controllable thickness by ion implantation of strontium titanate is reported here using low energy He+ ions. The induced strain follows a distribution within a typical near-surface layer of 200 nm as obtained from structural analysis. Due to clamping effect from the underlying layer, only perpendicular expansion is observed. Maximum distortions up to 5-7% are obtained with no evidence of amorphisation at fluences of 1E16 He+ ions/cm2 and ion energies in the range 10-30 keV.Comment: 11 pages, 4 figures, Accepted for publication in Europhysics Letter (http://iopscience.iop.org/0295-5075

Rivalry and uncertainty in complementary investments with dynamic market sharing

We study the effects of revenue and investment cost uncertainty, as well non- preemption duopoly competition, on the timing of investments in two complementary inputs, where either spillover-knowledge is allowed or proprietary-knowledge holds. We find that the ex-ante and ex-post revenue market shares play a very important role in firms’ behavior. When competition is considered, the leader’s behavior departs from that of the monopolist firm of Smith (Ind Corp Change 14:639–650, 2005). The leader is justified in following the conventional wisdom (i.e., synchronous investments are more likely), whereas, the follower’s behavior departs from that of the conventional wisdom (i.e., asynchronous investments are more likely)

Observations ichtyologiques effectuées en 1980

The authors give the distinctive characters of Lamna nasus, Isurus oxyrinchus and Carcharodon carcharias. They give data on the catch of Raja 1nicroocellata and its range in the Bay of Biscay, Raniceps raninus off Southwestern Oleron island, Zenopsis conchifer in the Bay of Biscay and off Southwestern Ireland, Cepola macrophthalma from Pertuis Charentais and a blue-fin tunny of about 400 kg.Les auteurs indiquent les caractères distinctifs de Lamna nasus, Jsurus oxyrinchus et Carcharodon carcharias. Puis, ils citent la capture de Raja microocellata, faisant le point sur la répartition de cette espèce dans le golfe de Gascogne, de Raniceps raninus au sud-ouest de l'île d'Oleron, de Zenopsis conchifer dans le golfe de Gascogne et à l'ouest de l'Irlande, de Cepola macrophthalma dans les Pertuis Charentais et d'un thon rouge de près de 400 kg

Pricing the Gamble for Resurrection and the Consequences of Renegotiation and Debt Design

This paper aims at measuring the loss in the value of a firm due to the gamble for resurrection, in a standard contingent claims model. Just before a debt repayment is due, the equityholders of a levered firm can decide to shut the firm down or to keep it as an ongoing concern. We study how leverage affects the operating decision and we provide a closed form formula for the associated agency costs. We show that yield spreads associated with defaultable bonds are higher than those obtained when ignoring the agency conflict.DEBT ; PRICING ; BONDS

A P.D.E. Approach to Asian Options: Analytical and Numerical Evidence.

We first derive a one state variable partial differential equation, easy to emplement, which characterizes the price of a European type Asian option. This result is explained and related to previous literature. When we derive new results on the hedging of an Asian option and propose analytical and numerical analysis on the comparison between Asian and European options. Our methodology which applies to "fixed-strike" Asian options as well to "floating-strike" Asian options completes and clarifies various results in the literature. In this paper we focus on "backward-starting" Asian options. Our approach is quite general however, and we explain how to adapt our main results to the case of "forward-starting" Asian options.FINANCIAL MARKET ; PRICING

Corporate Policies with Permanent and Transitory Shocks

We model the financing, cash holdings, and hedging policies of a firm facing financing frictions and subject to permanent and transitory cash flow shocks. We show that permanent and transitory shocks generate distinct, sometimes opposite, effects on corporate policies and use the model to develop a rich set of empirical predictions. In our model, correlated permanent and transitory shocks imply less risk, lower cash savings, and a drop in the value of credit lines. The composition of cash-flow shocks affects the cash-flow sensitivity of cash, which can be positive or negative. Optimal hedging of permanent and transitory shocks may involve opposite positions