Uniform Pricing or Pay-as-Bid Pricing: A Dilemma for California and Beyond

Any belief that a shift from uniform to as-bid pricing would provide power purchasers substantial relief from soaring prices is simply mistaken. The immediate consequence of its introduction would be a radical change in bidding behavior that would introduce new inefficiencies, weaken competition in new generation, and impede expansion of capacity.Auctions, Electricity Auctions, Multiple Item Auctions

Monomial integrals on the classical groups

This paper presents a powerfull method to integrate general monomials on the classical groups with respect to their invariant (Haar) measure. The method has first been applied to the orthogonal group in [J. Math. Phys. 43, 3342 (2002)], and is here used to obtain similar integration formulas for the unitary and the unitary symplectic group. The integration formulas turn out to be of similar form. They are all recursive, where the recursion parameter is the number of column (row) vectors from which the elements in the monomial are taken. This is an important difference to other integration methods. The integration formulas are easily implemented in a computer algebra environment, which allows to obtain analytical expressions very efficiently. Those expressions contain the matrix dimension as a free parameter.Comment: 16 page

Noxious and other bad weeds of Iowa

Within the past 15 years weeds have come to be recognized as the cause of one of the most important losses suffered by American farmers. Experiment station and extension workers, farmers, weed commissioners, insurance companies and farm credit agencies, chambers of commerce and others either directly or indirectly dependent on agriculture have become aroused by the menace of an increased dissemination of noxious weeds. In Iowa weeds cause a loss of many millions of dollars annually. They crowd out desirable crops, rob them of plant food and moisture, act as hosts for insects and disease-producing organisms of crops, poison or injure livestock, depreciate land values and cause extra labor in cultivation; thus they increase the cost of food production

Laboratory tests of field crop seeds as indicators of seeding value

Laboratory analysis and tests of seed samples were originally undertaken by governmental agencies in the United States and other countries to inform farmers concerning the weed seed content and plant producing capacity of seed lots. The determination of seed purity and the detection of seeds of noxious weeds have not proved difficult provided that representative samples of seed are submitted. Illustrations of weed seeds in bulletins and books, together with the use of herbarium specimens, have made it possible\u27 to identify with some degree of certainty foreign seeds found in crop seeds. Efforts to measure the plant producing capacity of seed lots have been less successful than to identify weed and crop seeds, because of (a) a lack of knowledge as to the factors affecting the viability and germination of many kinds of seeds, (b) difficulty of interpreting what constitutes normal germination and (c) inability to interpret the value of impermeable legume seeds in obtaining and maintaining field stands

An Aspen Plus Kinetic Model for the Gasification of Biomass in a Downdraft Gasifier

Gasification is a useful technology to recover energy from renewable biomass by producing a versatile syngas which can be converted into useful chemicals or fuels, or used directly for energy generation. The quality and composition of the syngas is highly dependent on the biomass feedstock, design parameters and process conditions, such as temperature, gasifying agent and Equivalence Ratio (ER). Downdraft gasifiers are considered to be a good option for low tar syngas production. In this work, a kinetic model for a downdraft gasifier is assembled and incorporated into a flowsheet using Aspen Plus with the aim of performing detailed process analysis. The model is organised according to the assumption that in a downdraft gasifier pyrolysis, oxidation and reduction occur almost as separate consecutive processes, with the pyrolysis considered as an instantaneously occurring process while oxidation and reduction are governed by chemical kinetics. The model has been validated against experimental data for different conditions of ER ranging from 0.2 to 0.35. The results show an overall agreement of the main species, with slight discrepancies in the prediction of CH4, which is over-predicted at lower ERs and under predicted at ER 0.345. This has an effect on the calculated Lower Heating Value (LHV) of the syngas which is generally higher than the experimental value. A set of sensitivity analyses were performed to investigate the impact of the value of the Char Reactivity Factor (CRF) on the composition of the producer gas and the kinetic parameters used in the model on the production of CH4. Sensitivity analyses show that a CRF of 14 gives the best prediction of the syngas composition and that the kinetics of the reactions in the reduction zone do not have a large impact on the final levels of methane in the syngas. More important is the sensitivity to variation of the kinetic parameters in the oxidation stage. By doubling the rate of oxidation of CH4 in the oxidation zone, the final levels of CH4 in the syngas are reduced by almost 20%

The viability and germination of seeds of Convolvulus Arvensis L. and other perennial weeds

From 1935 to 1939 inclusive, laboratory and field studies were made of the production, viability, impermeability, longevity and germination of seeds of Convolvulus arvensis L. and of other deep-rooted perennial weeds. A summary of the results is as follows: Bindweed plants, Convolvulus arvensis, produced an abundance of seed in seasons of high temperature and low rainfall. Periods of cloudy weather restricted blossoming and seed production. Production of normal seedlings by seeds, immediately after collection on the plants, varied from 7 to 24 percent, impermeability in the same collections varied from 28 to 91 percent and dead seeds ranged from 2 to 51 percent. The range in percentage of dead seeds in lots from 1 to 72 years old was 2 to 100

Individual Values and SME Environmental Engagement

We study the values on which managers of small and medium-sized enterprises draw when constructing their personal and organizational-level engagement with environmental issues, particularly climate change. Values play an important mediating role in business environmental engagement but relatively little research has been conducted on individual values in smaller organizations. Using the Schwartz Value System (SVS) as a framework for a qualitative analysis, we identify four ‘ideal-types’ of SME managers and provide rich descriptions of the ways in which values shape their constructions of environmental engagement. In contrast to previous research, which is framed around a binary divide between self-enhancing and self-transcending values, our typology distinguishes between individuals drawing primarily on Power or on Achievement values, and indicates how a combination of Achievement and Benevolence values is particularly significant in shaping environmental engagement. This demonstrates the theoretical usefulness of focusing on a complete range of values. Implications for policy and practice are discussed