Information Variability Impacts in Auctions

A wide variety of auction models exhibit close relationships between the winner's expected profit and the expected difference between the highest and second-highest order statistics of bidders' information, and between expected revenue and the second-highest order statistic of bidders' expected asset values. We use stochastic orderings to see when greater environmental variability of bidders' information enhances expected profit and expected revenue

Investigation of spray dispersion and particulate formation in diesel fuel flames

An experimental study of electrostatical atomized and dispersed diesel fuel jets was conducted at various back pressures to 40 atm. A new electrostatic injection technique was utilized to generate continuous, stable fuel sprays at charge densities of 1.5 to 2.0 C/m3 of fluid at one atm, and about 1.0 C/m3 at 40 atm. Flowrates were varied from 0.5 to 2.5 ml/s and electric potentials to -18 kV. Visual observations showed that significant enhanced dispersion of charged fuel jets occurred at high back pressures compared to aerodynamic breakup and dispersion. The average drop size was about the same as the spray triode orifice diameter, and was between the Kelly theory and the Rayleigh limit. The ignition tests, done only at one atm, indicated stable combustion of the electrostatically dispersed fuel jets

Book Reviews

The Hebrew God: Portrait of an Ancient Deity Lang, Bernhard New Haven and London: Yale University Press, 2002 Reviewed By Bill T. Arnold A Marginal Jew, vol. 3, Companions and Competitors Meier, John P New York, N.Y.: Doubleday, 2001 Reviewed By Mattie Greathouse The Gospel of Mark: A Soda-Rhetorical Commentary Witherington, Ill, Ben Grand Rapids: William B. Eerdmans, 2001 Reviewed By Greg Carey After Our Likeness: The Church as the Image of the Trinity. Trans. Doug Scott Voli, Miroslav Grand Rapids, MI: William B. Eerdmans, 1998 Reviewed By Howard A. Snyder The Literary Structure of the Old Testament: A Commentary on Genesis-Malachi Dorsey, David A. Grand Rapids: Baker, 1999 Reviewed By Joel H. Hunt Make the Old Testament Live: From Curriculum to Classroom Hess, Richard S., and Cordon J. Wenham, editors Eerdmans, 1998 Reviewed By Joel H. Hunt Christology Schwarz, Hans Grand Rapids : William B. Eerdmans, 1998 Reviewed By Greg Carey New Testament History: A Narrative Account Witherington, Ben Grand Rapids: Baker, 2001 Reviewed By Ruth Anne Reese The Omphalos and the Cross: Pagans and Christians in Search of a Divine Center Ciholas, Paul Macon : Mercer University Press, 2003 Reviewed By Michael Harstad Participating in God: Creation and Trinity Powell, Samuel M. Minneapolis: Fortress Press, 2003 Reviewed By James Holsinger Judges. Interpretation Commentary Series McCann, J. Clinton Louisville: Westminster/John Knox, 2002 Reviewed By Victor H. Matthews Clark H. Pinnock: Journey Toward Renewal: An Intellectual Biography Callen, Barry L Published in Cooperation with The Wesleyan Theological Society. Nappanee, IN: Evangel Publishing House, 2000 Reviewed By Howard A. Snyder Radical Christianity: The Believers Church Tradition in Christianity\u27s History and Future Callen, Barry L Nappanee, IN: Evangel Publishing House, 1999 Reviewed By Howard A. Snyder The Unity Movement Vahle, Neal Philadelphia: Templeton Foundation Press, 2002 Reviewed By Steven Tsoukala

Characterization and fluid flow simulation of naturally fractured Frontier sandstone, Green River Basin, Wyoming

Significant gas reserves are present in low-permeability sandstones of the Frontier Formation in the greater Green River Basin, Wyoming. Successful exploitation of these reservoirs requires an understanding of the characteristics and fluid-flow response of the regional natural fracture system that controls reservoir productivity. Fracture characteristics were obtained from outcrop studies of Frontier sandstones at locations in the basin. The fracture data were combined with matrix permeability data to compute an anisotropic horizontal permeability tensor (magnitude and direction) corresponding to an equivalent reservoir system in the subsurface using a computational model developed by Oda (1985). This analysis shows that the maximum and minimum horizontal permeability and flow capacity are controlled by fracture intensity and decrease with increasing bed thickness. However, storage capacity is controlled by matrix porosity and increases linearly with increasing bed thickness. The relationship between bed thickness and the calculated fluid-flow properties was used in a reservoir simulation study of vertical, hydraulically-fractured and horizontal wells and horizontal wells of different lengths in analogous naturally fractured gas reservoirs. The simulation results show that flow capacity dominates early time production, while storage capacity dominates pressure support over time for vertical wells. For horizontal wells drilled perpendicular to the maximum permeability direction a high target production rate can be maintained over a longer time and have higher cumulative production than vertical wells. Longer horizontal wells are required for the same cumulative production with decreasing bed thickness

Geotechnology for low-permeability gas reservoirs, 1995

The permeability, and thus the economics, of tight reservoirs are largely dependent on natural fractures, and on the in situ stresses that both originated fractures and control subsequent fracture permeability. Natural fracture permeability ultimately determines the gas (or oil) producibility from the rock matrix. Therefore, it is desirable to be able to predict, both prior to drilling and during reservoir production, (1) the natural fracture characteristics, (2) the mechanical and transport properties of fractures and the surrounding rock matrix, and (3) the present in situ stress magnitudes and orientations. The combination of activities described in this report extends the earlier work to other Rocky Mountain gas reservoirs. Additionally, it extends the fracture characterizations to attempts of crosswell geophysical fracture detection using shear wave birefringence and to obtaining detailed quantitative models of natural fracture systems for use in improved numerical reservoir simulations. Finally, the project continues collaborative efforts to evaluate and advance cost-effective methods for in situ stress measurements on core

Attention deficit hyperactivity symptoms predict problematic mobile phone use

Attention-deficit-hyperactivity disorder (ADHD) is the most commonly diagnosed childhood disorder characterised by inattention, hyperactivity/impulsivity, or both. Some of the key traits of ADHD have previously been linked to addictive and problematic behaviours. The aim of the present study was to examine the relationship between problematic mobile phone use, smartphone addiction risk and ADHD symptoms in an adult population. A sample of 273 healthy adult volunteers completed the Adult ADHD Self-Report Scale (ASRS), the Mobile Phone Problem Usage Scale (MPPUS), and the Smartphone Addiction Scale (SAS). A significant positive correlation was found between the ASRS and both scales. More specifically, inattention symptoms and age predicted smartphone addiction risk and problematic mobile phone use. Our results suggest that there is a positive relationship between ADHD traits and problematic mobile phone use. In particular, younger adults with higher level of inattention symptoms could be at higher risk of developing smartphone addiction. The implication of our findings for theoretical frameworks of problematic mobile phone use and clinical practice are discussed

Dual-barrel conductance micropipet as a new approach to the study of ionic crystal dissolution kinetics

A new approach to the study of ionic crystal dissolution kinetics is described, based on the use of a dual-barrel theta conductance micropipet. The solution in the pipet is undersaturated with respect to the crystal of interest, and when the meniscus at the end of the micropipet makes contact with a selected region of the crystal surface, dissolution occurs causing the solution composition to change. This is observed, with better than 1 ms time resolution, as a change in the ion conductance current, measured across a potential bias between an electrode in each barrel of the pipet. Key attributes of this new technique are: (i) dissolution can be targeted at a single crystal surface; (ii) multiple measurements can be made quickly and easily by moving the pipet to a new location on the surface; (iii) materials with a wide range of kinetics and solubilities are open to study because the duration of dissolution is controlled by the meniscus contact time; (iv) fast kinetics are readily amenable to study because of the intrinsically high mass transport rates within tapered micropipets; (v) the experimental geometry is well-defined, permitting finite element method modeling to allow quantitative analysis of experimental data. Herein, we study the dissolution of NaCl as an example system, with dissolution induced for just a few milliseconds, and estimate a first-order heterogeneous rate constant of 7.5 (±2.5) × 10–5 cm s–1 (equivalent surface dissolution flux ca. 0.5 μmol cm–2 s–1 into a completely undersaturated solution). Ionic crystals form a huge class of materials whose dissolution properties are of considerable interest, and we thus anticipate that this new localized microscale surface approach will have considerable applicability in the future