Parametric analysis of closed cycle magnetohydrodynamic (MHD) power plants

A parametric analysis of closed cycle MHD power plants was performed which studied the technical feasibility, associated capital cost, and cost of electricity for the direct combustion of coal or coal derived fuel. Three reference plants, differing primarily in the method of coal conversion utilized, were defined. Reference Plant 1 used direct coal fired combustion while Reference Plants 2 and 3 employed on site integrated gasifiers. Reference Plant 2 used a pressurized gasifier while Reference Plant 3 used a ""state of the art' atmospheric gasifier. Thirty plant configurations were considered by using parametric variations from the Reference Plants. Parametric variations include the type of coal (Montana Rosebud or Illinois No. 6), clean up systems (hot or cold gas clean up), on or two stage atmospheric or pressurized direct fired coal combustors, and six different gasifier systems. Plant sizes ranged from 100 to 1000 MWe. Overall plant performance was calculated using two methodologies. In one task, the channel performance was assumed and the MHD topping cycle efficiencies were based on the assumed values. A second task involved rigorous calculations of channel performance (enthalpy extraction, isentropic efficiency and generator output) that verified the original (task one) assumptions. Closed cycle MHD capital costs were estimated for the task one plants; task two cost estimates were made for the channel and magnet only

A critical edition of John Bunyan's posthumously published treatise Of Antichrist, and His Ruine (1692)

This thesis is a scholarly edition of Bunyan's treatise Of Antichrist, and His Ruine. The text is based on the first edition of 1692, retaining the spelling, punctuation, grammar, capitalization and italicization of the original. Printer's errors have been corrected; inaccurate Scriptural references have been corrected in the text, and the original references noted in the apparatus. Explanatory notes to the text provide additional Scriptural references., definitions of words or phrases now obsolete or liable to misinterpretation, and cross-references to other works by Bunyan and his contemporaries. The Introduction discusses first the circumstances of the publication of the treatise in a Folio collection of Bunyan's works edited by his friend and disciple, Charles Doe. It goes on to argue, on internal evidence, that the composition of the treatise can be dated to the early 1680s. There follows a brief account of the Antichrist legend, tracing its inception in the early church, its development in medieval thought and art, and early Protestant identification of Antichrist with the papacy. The views of seventeenth-century Protestant commentators concerning the fall of Antichrist and the commencement of Christ's millennial reign on earth are outlined, and the extent. of millenarian expectation in the 1640s and 1650S is described. Bunyan's early millenarian beliefs are discussed especially as set forth in his treatise The Holy City (1665). Although some historians have argued that interest in Antichrist and the millennium died away after the Restoration, evidence is presented to show that Bunyan's concern with the fall of Antichrist was not unusual in the early 1680s. The main features of his treatise are discussed and set in context, particularly its style, Bunyan's concept of Antichrist, his account of the slaying of the witnesses, and his belief that God would use Kings to destroy the physical body of Antichrist

A microgravity isolation mount

The design and preliminary testing of a system for isolating microgravity sensitive payloads from spacecraft vibrational and impulsive disturbances is discussed. The Microgravity Isolation Mount (MGIM) concept consists of a platform which floats almost freely within a limited volume inside the spacecraft, but which is constrained to follow the spacecraft in the long term by means of very weak springs. The springs are realized magnetically and form part of a six degree of freedom active magnetic suspension system. The latter operates without any physical contact between the spacecraft and the platform itself. Power and data transfer is also performed by contactless means. Specifications are given for the expected level of input disturbances and the tolerable level of platform acceleration. The structural configuration of the mount is discussed and the design of the principal elements, i.e., actuators, sensors, control loops and power/data transfer devices are described. Finally, the construction of a hardware model that is being used to verify the predicted performance of the MGIM is described

Pasture Weaning and Forage Barley to Extend the Grazing Season for Replacement Heifers

In a two-year study at the SDSU Cow/Calf Teaching and Research Unit, Brookings, SD, heifer calves were allotted to two weaning management treatments in early October at an average age of 202 days. The pasture-weaned group was separated from their dams and grazed grass pasture across the fence from their dams for two weeks. Then, until early December, they grazed “Robust” barley (forage type) that had been no-till planted into oat stubble in early August. The drylot-weaned group was fed a traditional weaning diet of grass hay, corn, and protein supplement from weaning until early December. The effect of management on heifer weight gain depended on year. In the first year, pasture-weaned heifers gained more than the drylot group during the first two weeks after weaning. Due to less than ideal pasture conditions in the second year, the drylot group gained more than the pasture weaned group for two and four weeks after weaning. In both years, gains from weaning to the end of the grazing period in December and to the following April were similar between management systems. Pasture weaning appeared to cause less stress for both cows and calves, but no differences in disease symptoms were observed. Antibody titers for IBR, BVD type 1 and BVD type 2 were determined at weaning and two and four weeks after weaning to measure the development of immunity from vaccinations administered two months prior to and at weaning. At two weeks after weaning in the second year of the study, antibody titer for BVD type 1 was greater for the drylot group than the pasture-weaned group. By four weeks after weaning the pasture-weaned heifers had antibody titers similar to the drylot group. The results of this study indicate that pasture weaning combined with small grain pasture to extend the grazing system can be an effective alternative for managing replacement heifers compared to a traditional drylot weaning system

Moored velocity measurements on the edge of the Gulf-Stream recirculation

Mean velocities, eddy kinetic energies and time series of velocities at several depths are presented from moored current meters for the 15 month period May 1978 to July 1979 as part of the POLYMODE Local Dynamics Experiment, centered at 31N, 69°30\u27W. The mean velocities in the upper one kilometer are toward the southwest at 2.4 to 4.4 cm/s, consistent with Worthington\u27s (1976) description of the mean circulation of the North Atlantic...

Social Work Faculty Perceptions of the Leadership Qualities of Their Academic Leaders

Leadership within the social work academic setting is unique and complex. Understanding the way in which faculty members experience the leadership qualities of their academic leaders is a necessary precursor to effective leadership development. This article reports on the quantitative data from a mixed-methods, nationwide survey exploring social work faculty perceptions of the leadership qualities of their academic programs\u27 leaders

Supersonic Crossflow Transition Control in Ground and Flight Tests

This paper describes the use of distributed-roughness-element (DRE) patterns along a Mach 2 design swept-wing leading edge to increase the laminar flow extent and thereby reduce drag. One swept-wing model was tested in a supersonic wind tunnel as well as beneath a supersonic flight vehicle. Wing model surface data acquired during these tests included pressures, temperatures, and boundary-layer transition locations. Similarities and differences in experimental results are discussed. While wind tunnel and flight results show some differences, the wind tunnel results still provide key insights necessary for understanding how to design effective DRE patterns for use in flight applications. Experimental results demonstrate a DRE flow control effect observed in flight similar to that observed in the wind tunnel. Finally, a different perspective is discussed concerning what flow control role RE patterns might perform in any future swept-wing laminar flow control applications

Uncertainties in determining parton distributions at large x

We critically examine uncertainties in parton distribution functions (PDFs) at large x arising from nuclear effects in deuterium F2 structure function data. Within a global PDF analysis, we assess the impact on the PDFs from uncertainties in the deuteron wave function at short distances and nucleon off-shell effects, the use of relativistic kinematics, as well as the use of less a restrictive parametrization of the d/u ratio. We find that in particular the d-quark and gluon PDFs vary significantly with the choice of nuclear model. We highlight the impact of these uncertainties on the determination of the neutron structure function, and on W boson production and parton luminosity at the Tevatron and the LHC. Finally, we discuss prospects for new measurements sensitive to the d-quark and gluon distributions but insensitive to nuclear corrections.Comment: 37 pages, 13 figures. Final published versio

Embedding the concept of ecosystems services:The utilisation of ecological knowledge in different policy venues

The concept of ecosystem services is increasingly being promoted by academics and policy makers as a means to protect ecological systems through more informed decision making. A basic premise of this approach is that strengthening the ecological knowledge base will significantly enhance ecosystem health through more sensitive decision making. However, the existing literature on knowledge utilisation, and many previous attempts to improve decision making through better knowledge integration, suggest that producing ‘more knowledge’ is only ever a necessary but insufficient condition for greater policy success. We begin this paper by reviewing what is already known about the relationship between ecological knowledge development and utilisation, before introducing a set of theme issue papers that examine—for the very first time—how this politically and scientifically salient relationship plays out across a number of vital policy venues such as land-use planning, policy-level impact assessment, and cost–benefit analysis. Following a detailed synthesis of the key findings of all the papers, this paper identifies and explores new research and policy challenges in this important and dynamic area of environmental governance

The radius and mass of the subgiant star bet Hyi from interferometry and asteroseismology

We have used the Sydney University Stellar Interferometer (SUSI) to measure the angular diameter of beta Hydri. This star is a nearby G2 subgiant whose mean density was recently measured with high precision using asteroseismology. We determine the radius and effective temperature of the star to be 1.814+/-0.017 R_sun (0.9%) and 5872+/-44 K (0.7%) respectively. By combining this value with the mean density, as estimated from asteroseismology, we make a direct estimate of the stellar mass. We find a value of 1.07+/-0.03 M_sun (2.8%), which agrees with published estimates based on fitting in the H-R diagram, but has much higher precision. These results place valuable constraints on theoretical models of beta Hyi and its oscillation frequencies.Comment: 3 figures, 3 tables, to appear in MNRAS Letter