The Impact of Market Rules and Market Structure on the Price Determination Process in the England and Wales Electricity Market

This paper argues that the market rules governing the operation of the England and Wales electricity market in combination with the structure of this market presents the two major generators National Power and PowerGen with opportunities to earn revenues substantially in excess of their costs of production for short periods of time. Generators competing to serve this market have two strategic weapons at their disposal: (1) the price bid for each generation set and (2) the capacity of each generation set made available to supply the market each half-hour period during the day. We argue that because of the rules governing the price determination process in this market, by the strategic use of capacity availability declarations, when conditions exogenous to the behavior of the two major generators favor it, these two generators are able to obtain prices for their output substantially in excess of their marginal costs of generation. The paper establishes these points in the following manner. First, we provide a description of the market structure and rules governing the operation of the England and Wales electricity market, emphasizing those aspects that are important to the success of the strategy we believe the two generators use to exercise market power. We then summarize the time series properties of the price of electricity emerging from this market structure and price-setting process. By analyzing four fiscal years of actual market prices, quantities and generator bids into the market, we provide various pieces of evidence in favor of the strategic use of the market rules by the two major participants. The paper closes with a discussion of the lessons that the England and Wales experience can provide for the design of competitive power markets in the US, particularly California, and other countries.

Cryogenic Insulation System

This invention relates to reusable, low density, high temperature cryogenic foam insulation systems and the process for their manufacture. A pacing technology for liquid hydrogen fueled, high speed aircraft is the development of a fully reusable, flight weight cryogenic insulation system for propellant tank structures. In the invention cryogenic foam insulation is adhesively bonded to the outer wall of the fuel tank structure. The cryogenic insulation consists of square sheets fabricated from an array of abutting square blocks. Each block consists of a sheet of glass cloth adhesively bonded between two layers of polymethacrylimide foam. Each block is wrapped in a vapor impermeable membrane, such as Kapton(R) aluminum Kapton(R), to provide a vapor barrier. Very beneficial results can be obtained by employing the present invention in conjunction with fibrous insulation and an outer aeroshell, a hot fuselage structure with an internal thermal protection system

An estimate of the uptake of atmospheric methyl bromide by agricultural soils

Published estimates of removal of atmospheric methyl bromide (CH3Br) by agricultural soils are 2.7 Gg yr−1 (Gg = 109 g) [Shorter et al., 1995] and 65.8 Gg yr−1 [Serça et al., 1998]. The Serça et al. estimate, if correct, would suggest that the current value for total removal of atmospheric CH3Br by all sinks of 206 Gg yr−1 (based on Shorter et al., 1995) would be 30% too low. We have calculated a new rate of global agricultural soil uptake of atmospheric CH3Br from a larger sampling of cultivated soils collected from 40 sites located in the United States, Costa Rica, and Germany. First order reaction rates were measured during static laboratory incubations. These data were combined with uptake measurements we reported earlier based on field and laboratory experiments [Shorter et al. 1995]. Tropical (10.2°–10.4°N) and northern (45°–61°N) soils averaged lower reaction rate constants than temperate soils probably due to differing physical and chemical characteristics as well as microbial populations. Our revised global estimate for the uptake of ambient CH3Br by cultivated soils is 7.47±0.63 Gg yr−1, almost three times the value that we reported in 1995

Muscle Fatigue from the Perspective of a Single Crossbridge

The repeated intense stimulation of skeletal muscle rapidly decreases its force- and motion-generating capacity. This type of fatigue can be temporally correlated with the accumulation of metabolic by-products, including phosphate (Pi) and protons (H+). Experiments on skinned single muscle fibers demonstrate that elevated concentrations of these ions can reduce maximal isometric force, unloaded shortening velocity, and peak power, providing strong evidence for a causative role in the fatigue process. This seems to be due, in part, to their direct effect on muscle’s molecular motor, myosin, because in assays using isolated proteins, these ions directly inhibit myosin’s ability to move actin. Indeed, recent work using a single molecule laser trap assay has revealed the specific steps in the crossbridge cycle affected by these ions. In addition to their direct effects, these ions also indirectly affect myosin by decreasing the sensitivity of the myofilaments to calcium, primarily by altering the ability of the muscle regulatory proteins, troponin and tropomyosin, to govern myosin binding to actin. This effect seems to be partially due to fatigue-dependent alterations in the structure and function of specific subunits of troponin. Parallel efforts to understand the molecular basis of muscle contraction are providing new technological approaches that will allow us to gain unprecedented molecular detail of the fatigue process. This will be crucial to fully understand this ubiquitous phenomenon and develop appropriately targeted therapies to attenuate the debilitating effects of fatigue in clinical populations

An analytically linearized helicopter model with improved modeling accuracy

An analytically linearized model for helicopter flight response including rotor blade dynamics and dynamic inflow, that was recently developed, was studied with the objective of increasing the understanding, the ease of use, and the accuracy of the model. The mathematical model is described along with a description of the UH-60A Black Hawk helicopter and flight test used to validate the model. To aid in utilization of the model for sensitivity analysis, a new, faster, and more efficient implementation of the model was developed. It is shown that several errors in the mathematical modeling of the system caused a reduction in accuracy. These errors in rotor force resolution, trim force and moment calculation, and rotor inertia terms were corrected along with improvements to the programming style and documentation. Use of a trim input file to drive the model is examined. Trim file errors in blade twist, control input phase angle, coning and lag angles, main and tail rotor pitch, and uniform induced velocity, were corrected. Finally, through direct comparison of the original and corrected model responses to flight test data, the effect of the corrections on overall model output is shown

First records of the grasshopper \u3ci\u3eMachaerocera mexicana\u3c/i\u3e Saussure, 1859 (Orthoptera: Acrididae) from the United States and Sonora, Mexico

The grasshopper Machaerocera mexicana Saussure (Orthoptera: Acrididae) is added to the orthopteran faunas of the United States and Sonora, Mexico. Notes are presented on habitat and seasonality. El saltamontes Machaerocera mexicana Saussure (Orthoptera: Acrididae) se agrega a las faunas ortópteros de los Estados Unidos y Sonora, México. Se presenta notas sobre su hábitat y estacionalidad

First records of the grasshopper \u3ci\u3eMachaerocera mexicana\u3c/i\u3e Saussure, 1859 (Orthoptera: Acrididae) from the United States and Sonora, Mexico

The grasshopper Machaerocera mexicana Saussure (Orthoptera: Acrididae) is added to the orthopteran faunas of the United States and Sonora, Mexico. Notes are presented on habitat and seasonality. El saltamontes Machaerocera mexicana Saussure (Orthoptera: Acrididae) se agrega a las faunas ortópteros de los Estados Unidos y Sonora, México. Se presenta notas sobre su hábitat y estacionalidad

Patient-specific CFD simulation of intraventricular haemodynamics based on 3D ultrasound imaging

Background: The goal of this paper is to present a computational fluid dynamic (CFD) model with moving boundaries to study the intraventricular flows in a patient-specific framework. Starting from the segmentation of real-time transesophageal echocardiographic images, a CFD model including the complete left ventricle and the moving 3D mitral valve was realized. Their motion, known as a function of time from the segmented ultrasound images, was imposed as a boundary condition in an Arbitrary Lagrangian-Eulerian framework. Results: The model allowed for a realistic description of the displacement of the structures of interest and for an effective analysis of the intraventricular flows throughout the cardiac cycle. The model provides detailed intraventricular flow features, and highlights the importance of the 3D valve apparatus for the vortex dynamics and apical flow. Conclusions: The proposed method could describe the haemodynamics of the left ventricle during the cardiac cycle. The methodology might therefore be of particular importance in patient treatment planning to assess the impact of mitral valve treatment on intraventricular flow dynamics