Relativistic precession and spin dynamics of an elliptic Rydberg wave packet

Time evolution of wave packets built from the eigenstates of the Dirac equation for a hydrogenic system is considered. We investigate the space and spin motion of wave packets which, in the non-relativistic limit, are stationary states with a probability density distributed uniformly along the classical, elliptical orbit (elliptic WP). We show that the precession of such a WP, due to relativistic corrections to the energy eigenvalues, is strongly correlated with the spin motion. We show also that the motion is universal for all hydrogenic systems with an arbitrary value of the atomic number Z.Comment: Latex2e, uses IOP style files (included), 10 pages, 5 jpg figures, 1 postscript figure. Relation between precession time and radiative liftime added (eq.(12)). Accepted for publication in J. Phys.

INCREASED EGG CONSERVATION-IS IT ESSENTIAL FOR RECOVERY OF WHOOPING CRANES IN THE ARANSASIWOOD BUFFALO POPULATION?

The whooping crane (Grus americana) is in a race for survival against adversities (genetic, demographic, and environmental) that are only partially understood. There is increasing evidence of genetic problems (drift, inbreeding, and loss of heterozygosity) in the captive population that likely also exist in the wild Aransas-Wood Buffalo Population (A WP), a consequence of the 1940s population bottleneck. Small populations are vulnerable to extinction through catastrophic events and random changes in productivity or survival. Negative environmental effects faced by whooping cranes include upstream diversion which diminish freshwater (nutrient) inflow into Texas wintering habitats, and expanding human activities along the coast of the Gulf of Mexico. Population and genetic specialists tell us that security against genetic problems, demographic fluctuations, and environmental changes, lies in maximizing population size. An appropriate minimum population goal to overcome the aforementioned problems is 1,000 individuals (Shaffer 1981, Salwasser et al. 1984, Mirande et al. 1993). The Canadian- United States Whooping Crane Recovery Team has accepted 1,000 birds as their goal for the A WP. If habitat is not limiting and inbreeding does not depress viability (rather large uncertainties), another 30+ years must pass before the A WP reaches 1,000 individuals (Mirande et al. 1993). Can the A WP survive 30+ years to reach a minimum secure population level? It seems evident that managers should be cautious and consider what might be done to accelerate A WP growth. Two potential techniques come to mind. One would be to supplement the population with introductions of captive-reared cranes. In previous brief discussions by the recovery teams, this approach has been discounted because of potential disease transmission to the only wild self-sustaining population. The second technique would be to initiate intensive egg management (Fig. 1) as described by Ellis and Gee (2001)

In-flight rain damage tests of the shuttle thermal protection system

NASA conducted in-flight rain damage tests of the Shuttle thermal protection system (TPS). Most of the tests were conducted on an F-104 aircraft at the Dryden Flight Research Facility of NASA's Ames Research Center, although some tests were conducted by NOAA on a WP-3D aircraft off the eastern coast of southern Florida. The TPS components tested included LI900 and LI2200 tiles, advanced flexible reusable surface insulation, reinforced carbon-carbon, and an advanced tufi tile. The objective of the test was to define the damage threshold of various thermal protection materials during flight through rain. The test hardware, test technique, and results from both F-104 and WP-3D aircraft are described. Results have shown that damage can occur to the Shuttle TPS during flight in rain

Pre-Meal Effect of Whey Proteins on Metabolic Parameters in Subjects with and without Type 2 Diabetes:A Randomized, Crossover Trial

Diabetic dyslipidemia with elevated postprandial triglyceride (TG) responses is characteristic in type 2 diabetes (T2D). Diet and meal timing can modify postprandial lipemia (PPL). The impact of a pre-meal of whey proteins (WP) on lipid metabolism is unidentified. We determined whether a WP pre-meal prior to a fat-rich meal influences TG and apolipoprotein B-48 (ApoB-48) responses differentially in patients with and without T2D. Two matched groups of 12 subjects with and without T2D accomplished an acute, randomized, cross-over trial. A pre-meal of WP (20 g) or water (control) was consumed 15 min before a fat-rich meal (supplemented with 20 g WP in case of water pre-meal). Postprandial responses were examined during a 360-min period. A WP pre-meal significantly increased postprandial concentrations of insulin (P < 0.0001), glucagon (P < 0.0001) and glucose-dependent insulinotropic peptide (GIP) (P < 0.0001) in subjects with and without T2D. We detected no effects of the WP pre-meal on TG, ApoB-48, or non-esterified fatty acids (NEFA) responses to the fat-rich meal in either group. Paracetamol absorption i.e. gastric emptying was delayed by the WP pre-meal (P = 0.039). In conclusion, the WP pre-meal induced similar hormone and lipid responses in subjects with and without T2D. Thus, the WP pre-meal enhanced insulin, glucagon and GIP responses but did not influence lipid or glucose responses. In addition, we demonstrated that a WP pre-meal reduced gastric emptying in both groups

Emergency Services Research in Great Britain

On a trip to Great Britain during July 1975, I talked with a number of people engaged in research on municipal emergency services. This working paper summarizes these conversations. It is being circulated as a WP because its technical content may be of interest to a number of people within IIASA

Classical Arabic verb inflection: a WP-grammar, with an introductory phonemic investigation

This work presents a new grammar of the Classical Arabic Verb Inflection, carried out within the system of the WP morphological theory (the Word and Paradigm model of analysis as formalized by Professor P. H. Matthews). It is thus basically an application of this structural theory, rather than an assessment of its merits. Yet a general evaluation of characteristics of this theory, compared with two other interrelated systems, is presented with"particular attention to the concept of adequacy' in relation to Arabic grammar. The thesis consists of six chapters, the first of which represents an elaborated introduction meant to define the implicit questionable points that the title may raise. This is followed by a chapter on phonemic investigation, restricted to the problematic areas where the scholarly dispute over a specific number of Arabic phonemes has been building up since the Classical era. The terminological distinctions between the basic traditional terms of Arabic grammar and their presumed equivalents in modern linguistics is discussed in Chapter III as a prelude to the major body of the work. Chapter IV reviews, first, the three relevant linguistic models of analysis in relation to the morphology of Classical Arabic, which is taken here beyond the restrictive study of the individual language to the domain of the general linguistic theory; and, second, it presents a comprehensive summary of WP: its basic terms, rule system and evaluational procedure, followed by the reasons that made it the ideal choice for the present purpose. Chapter V, which serves as a background to the application in Chapter VI, represents the core of the discussions devoted to the Classical Arabic verbal system. It comprises all the explanations that are possibly needed for the making and understanding of the grammatical rules, and which find no room in the final chapter without interrupting the flow of the rule divisions. The final chapter is merely an application of the WP model to the inflectional system of the Classical Arabic verb. It consists of the verbal grammatical rules, preceded by a minimized group of the required guiding notes, and followed by an exemplary demonstration of the drivational system. The thesis is ended with a Summary and Conclusions that survey the work in general and briefly record its findings. In addition to the original views and postulations distributed over almost all the chapters of this work, and apart from the empirical value regarding the theory adopted, the present grammar represents on the one hand a further step in the evolutional course of the Classical Arabic grammar, and on the other it provides a new link between this classical grammar and the continual evolution of the linguistic theory

Wind power with energy storage arbitrage in day-ahead market by a stochastic MILP approach

This paper is about a support information management system for a wind power (WP) producer having an energy storage system (ESS) and participating in a day-ahead electricity market. Energy storage can play not only a leading role in mitigation of the effect of uncertainty faced by a WP producer, but also allow for conversion of wind energy into electric energy to be stored and then released at favourable hours. This storage provides capability for arbitrage, allowing an increase on profit of a WP producer, but must be supported by a convenient problem formulation. The formulation proposed for the support information management system is based on an approach of stochasticity written as a mixed integer linear programming problem. WP and market prices are considered as stochastic processes represented by a set of scenarios. The charging/discharging of the ESS are considered dependent on scenarios of market prices and on scenarios of WP. The effectiveness of the proposed formulation is tested by comparison of case studies using data from the Iberian Electricity Market. The comparison is in favour of the proposed consideration of stochasticity