Nimbus Meteorological Satellite Integration and Testing Materials Report No. 8

Nimbus satellite component and materials environmental investigations, failure analyses, and quality control procedure

Impact of corrosion on fretting damage of electrical contacts

Electrical contacts are used in a large number of industrial applications, this includes all sorts of modern transportation: airplanes, trains and automobiles. Mechanical assemblies are subjected to vibrations and micro-displacements between mating surfaces are observed leading to fretting wear. Mechanical degradation can additionally be accelerated by a corrosive factor caused by variable humidity, temperature and corrosive gas attack. Fretting-corrosion leads to an increase of contact resistance or intermittent contact resistance faults as corrosion products change the nature of the interface primary through a range of film formation processes. In this work the impact of a corrosion product film formed on copper and gold surfaces on the electrical contact fretting behavior is shown. It has been observed that modification of the interface by the formation of the surface layer can surprisingly lead to increase of the electrical contact durability

Studies of Heavily Ionizing Particles and Space Biology Semiannual Report

Radiobiological and radiation medical studies on biological cel

Monetary policy in a Markov-switching VECM: implications for the cost of disinflation and the price puzzle

Monetary policy VARs typically presume stability of the long-run outcomes. We introduce the possibility of switches in the long-run equilibrium in a cointegrated VAR by allowing both the covariance matrix and weighting matrix in the error-correction term to switch. We find that monetary policy alternates between sustaining long-run growth and disinflationary regimes. Allowing state changes can also help explain the price puzzle and justify the use of commodity prices as a corrective measure. Finally, we show that regime-switching has implications for disinflationary monetary policy and can explain the variety of sacrifice ratio estimates that exist in the literature.Monetary policy ; Econometric models

Biology and Medicine, Spring 1965 Semiannual report

Reports on radiobiology studies, pion studies with silicon detectors, immunology, ultracentrifuge rotor temperature and speed measurement by radio telemetry, and radiosensitivity investigation

The use of long-run restrictions for the identification of technology shocks

The authors survey the recent empirical literature using long-run restrictions to identify technology shocks and provide an illustrative walk-through of the long-run restricted vector autoregression (VAR) methodology in a bivariate framework. Additionally, they offer an alternative identification of technology shocks that can be imposed by restrictions on the long-run impulse responses to evaluate the robustness of the conclusions drawn by the structural VAR literature. Their results from this methodology compare favorably with the empirical literature that uses structural VARs to identify technology shocks.Business cycles ; Technology

Synovial joint lubrication – does nature teach more effective engineering lubrication strategies?

Nature shows numerous examples of systems which show energy efficiency, elegance in their design and optimum use of materials. Biomimetics is an emerging field of research in engineering and successes have been documented in the diverse fields of robotics, mechanics, materials engineering and many more. To date little biomimetics research has been directed towards tribology in terms of transferring technologies from biological systems into engineering applications. The potential for biomimicry has been recognised in terms of replicating natural lubricants but this system reviews the potential for mimicking the synovial joint as an efficient and durable tribological system for potential engineering systems. The use of materials and the integration of materials technology and fluid/surface interactions are central to the discussion

What explains the varying monetary response to technology shocks in G-7 countries?

In a recent paper, Galí, López-Salido, and Vallés (2003) examined the Federal Reserve’s response to VAR-identified technology shocks. They found that during the Martin-Burns- Miller era, the Fed responded to technology shocks by overstabilizing output, while in the Volcker-Greenspan era, the Fed adopted an inflation-targeting rule. We extend their analysis to countries of the G-7; moreover, we consider the factors that may contribute to differing monetary responses across countries. Specifically, we find a relationship between the volatility of capital investment, type of monetary policy rule, the responsiveness of the rule to output and inflation fluctuations, and the response to technology shocks.Technology ; Monetary policy ; Taylor's rule

The low-frequency impact of daily monetary policy shocks

With rare exception, studies of monetary policy tend to neglect the timing of the innovations to the monetary policy instrument. Models which do take timing seriously are often difficult to compare to standard VAR models of monetary policy because of the differences in the frequency that they use. We propose an alternative model using MIDAS regressions which nests both ideas: Accurate (daily) timing of innovations to the monetary policy instrument are embedded in a monthly frequency VAR to determine the macroeconomic effects of high frequency changes to policy. We find that taking into account the timing of the shocks is important and can alleviate some of the puzzles in standard monthly VARs [e.g., the price puzzle]. We find that policy shocks are most important to variables thought of as being heavily expectations-oriented and that, contrary to some VAR studies, the effects of FOMC shocks on real variables are small.>Monetary policy ; Econometric models ; Prices

The local effects of monetary policy

Previous studies have documented disparities in the regional responses to monetary policy shocks; this variation has been found to depend, in part, on differences in the industrial composition of the regional economies. However, because of computational issues, the literature has often neglected the richest level of disaggregation: the city. In this paper, we estimate the city-level responses to monetary policy shocks in a Bayesian VAR. The Bayesian VAR allows us to model the entire panel of metropolitan areas through the imposition of a shrinkage prior. We then seek the origin of the city-level asymmetric responses.Vector autoregression ; Econometric models