Multilayer porous ionizer Patent

Multilayer porous refractory metal ionizer design with thick, porous, large-grain substrates and thin, porous micron-grain substrate

On Estimating an Asset's Implicit Beta

Siegel (1995) has developed a technique with which the systematic risk of a security (beta) can be estimated without recourse to historical capital market data. Instead, beta is estimated implicitly from the current market prices of exchange options that enable the exchange of a security against shares on the market index. Because this type of exchange options is not currently traded on the capital markets, Siegel's technique cannot yet be used in practice. This article will show that beta can also be estimated implicitly from the current market prices of plain vanilla options, based on the Capital Asset Pricing Model. --

The discount rate: a note on IAS 36

Measurement in financial accounting often requires determining an interest rate to discount future cash flows. One example is the International Accounting Standard (IAS)36 Impairment of assets. IAS 36´s impairment test requires determining a value in use (a present value). The Appendix A to the standard gives some guidance on how to determine a suitable discount rate. In this paper, we show that the different approaches included in IAS 36´s guidance are theoretically different. We discuss how the standard should be interpreted and applied based on the theoretical background of financial theory. Only the first alternative, we weighted cost of capital should be used and the other two alternatives should be discarded. In addition, we show that IAS 36´s guidance, applied in practice, may give rise to substential measurement errors. --

On Estimating an Asset's Implicit Beta

Siegel (1995) has developed a technique with which the systematic risk of a security (beta) can be estimated without recourse to historical capital market data. Instead, beta is estimated implicitly from the current market prices of exchange options that enable the exchange of a security against shares on the market index. Because this type of exchange options is not currently traded on the capital markets, Siegel's technique cannot yet be used in practice. This article will show that beta can also be estimated implicitly from the current market prices of plain vanilla options, based on the Capital Asset Pricing Model. We provide empirical evidence on implicit betas using prices of exchange options from the EUREX over years 2000 to 2004.Capital Asset Pricing Model, Beta, Option Pricing

Observation of Quantized Conductance in Neutral Matter

In transport experiments the quantum nature of matter becomes directly evident when changes in conductance occur only in discrete steps, with a size determined solely by Planck's constant h. The observations of quantized steps in the electric conductance have provided important insights into the physics of mesoscopic systems and allowed for the development of quantum electronic devices. Even though quantized conductance should not rely on the presence of electric charges, it has never been observed for neutral, massive particles. In its most fundamental form, the phenomenon requires a quantum degenerate Fermi gas, a ballistic and adiabatic transport channel, and a constriction with dimensions comparable to the Fermi wavelength. Here we report on the observation of quantized conductance in the transport of neutral atoms. We employ high resolution lithography to shape light potentials that realize either a quantum point contact or a quantum wire for atoms. These constrictions are imprinted on a quasi two-dimensional ballistic channel connecting two adjustable reservoirs of quantum degenerate fermionic lithium atoms. By tuning either a gate potential or the transverse confinement of the constrictions, we observe distinct plateaus in the conductance for atoms. The conductance in the first plateau is found to be equal to 1/h, the universal conductance quantum. For low gate potentials we find good agreement between the experimental data and the Landauer formula, with all parameters determined a priori. Our experiment constitutes the cold atom version of a mesoscopic device and can be readily extended to more complex geometries and interacting quantum gases.Comment: 7 pages, 4 figure

On Estimating an Asset's Implicit Beta

Siegel (1995) has developed a technique with which the systematic risk of a security (beta) can be estimated without recourse to historical capital market data. Instead, beta is estimated implicitly from the current market prices of exchange options that enable the exchange of a security against shares on the market index. Because this type of exchange options is not currently traded on the capital markets, Siegel's technique cannot yet be used in practice. This article will show that beta can also be estimated implicitly from the current market prices of plain vanilla options, based on the Capital Asset Pricing Model. We provide empirical evidence on implicit betas using prices of exchange options from the EUREX over years 2000 to 2004

Connecting strongly correlated superfluids by a quantum point contact

Point contacts provide simple connections between macroscopic particle reservoirs. In electric circuits, strong links between metals, semiconductors or superconductors have applications for fundamental condensed-matter physics as well as quantum information processing. However for complex, strongly correlated materials, links have been largely restricted to weak tunnel junctions. Here we study resonantly interacting Fermi gases connected by a tunable, ballistic quantum point contact, finding a non-linear current-bias relation. At low temperature, our observations agree quantitatively with a theoretical model in which the current originates from multiple Andreev reflections. In a wide contact geometry, the competition between superfluidity and thermally activated transport leads to a conductance minimum. Our system offers a controllable platform for the study of mesoscopic devices based on strongly interacting matter.Comment: 5 pages, 4 figures, 7 pages supplementar