Aluminum work function: Effect of oxidation, mechanical scraping and ion bombardment

Surface studies have been performed on aluminum polycrystalline surfaces which have been mechanically scraped. Such studies were initiated in order to understand surface effects occurring in tribological processes which involve rubbing surfaces and the effects of adsorption of oxygen. To characterize the surfaces, the following three different experimental approaches have been used: (1) X.P.S. (X-ray photoelectron spectroscopy), in order to check the cleanliness of the surfaces and follow the adsorption and oxidation kinetics; (2) Analysis of the work function changes by following the energy spectra of secondary electrons emitted under low energy electron bombardment; and (3) Analysis of photoemission intensities under U.V. excitation. The reference state being chosen to be the surface cleaned by ion bombardment and exposures to oxygen atmospheres have been shown to lower the work function of clean polycrystalline aluminum by 1.2 eV. The oxygen pressure is found to affect only the kinetics of these experiments. Mechanical scraping has been shown to induce a decrease ( 0.3 eV) in the work function, which could sharply modify the kinetics of adsorption on the surface

Cost recovery and pricing of payment services

A modern payment system is essential for promoting domestic and international trade and exchange as well as developing financial markets. Payment users will be directed toward the most efficient payment methods when the costs of producing those services are reflected in the prices paid. Resources are being wasted in the United States because consumers see no important difference in transaction prices or bank costs between using a check or using electronic direct debit in paying a bill, even though the social costs of these two instruments are different. Electronic payments cost only a third to half as much as paper-based payments. An estimated $100 billion (or 1.5 percent of GDP) is being lost by the continued use of paper-based checks. When payment instruments are not appropriately priced, the costs must be covered elsewhere. One common solution is to let loan revenues cover part of payment expenses (keeping loan rates higher to compensate). When prices reflect the full cost of producing the service, users demand the services that use the fewest real resources. The authors give examples of payment prices and price schedules and show how underlying cost data are used to"build up"to a price. They outline how payment services may best be structured to: a) Appropriately reflect economies of scale or scope in the production of payment services; b) Adjust cost recovery percentages to accommodate how much demand conditions associated with start-up differ from those associated with mature operation. (During a new system's early years of operation, the transaction volume may be low and some form of underrecovery of costs may be required to encourage use of the system. But any such underrecovery must be built into future pricing arrangements oncethe systems are established and traffic volumes are at a level where full cost recovery is practical. To ensure fairness, the pricing structure must also guarantee that latecomers to the system not get more favorable treatment than the initial user group.); and c) Induce efficient use of scarce resources. They note the economic principles that recommend certain pricing methods over others and apply equally to payment services provided by the private sector or through a government agency. They show why costs should be recovered through user transaction fees.Banks&Banking Reform,Payment Systems&Infrastructure,Economic Theory&Research,Markets and Market Access,Decentralization,Payment Systems&Infrastructure,Economic Theory&Research,Banks&Banking Reform,Environmental Economics&Policies,Markets and Market Access

Renormalization Group Equations for the CKM matrix

We derive the one loop renormalization group equations for the Cabibbo-Kobayashi-Maskawa matrix for the Standard Model, its two Higgs extension and the minimal supersymmetric extension in a novel way. The derived equations depend only on a subset of the model parameters of the renormalization group equations for the quark Yukawa couplings so the CKM matrix evolution cannot fully test the renormalization group evolution of the quark Yukawa couplings. From the derived equations we obtain the invariant of the renormalization group evolution for three models which is the angle $\alpha$ of the unitarity triangle. For the special case of the Standard Model and its extensions with $v_{1}\approx v_{2}$ we demonstrate that also the shape of the unitarity triangle and the Buras-Wolfenstein parameters $\bar{\rho}=(1-{1/2}\lambda^{2})\rho$ and $\bar{\eta}=(1-{1/2}\lambda^{2})\eta$ are conserved. The invariance of the angles of the unitarity triangle means that it is not possible to find a model in which the CKM matrix might have a simple, special form at asymptotic energies.Comment: 9 page