Application of Ion Cyclotron Resonance to the Study of Inelastic Excitation by Low-Energy Electrons

The geometry of the resonance cell employed for ion cyclotron resonance spectroscopy (1-3) is ideally suited for studying inelastic excitation by low-energy electrons. It has been shown that the electron beam traverses a parabolic potential well between the trapping electrodes, the depth of which is approximately half the applied trapping voltage (3,4). Low-energy electrons generated by impact excitation of an atomic or molecular energy level can be trapped in the resonance cell if their final translational energy is insufficient to escape the preset depth of the potential well. These electrons can be drifted from the source of the resonance region by applying the usual static drift field E normal to the primary magnetic field H (4). The electron drift velocity in this crossed field geometry, given by cE/H, is independent of both charge and mass. For typical values of E and H the drift velocity is in the range of 10^1-10^3 cm/sec. In the lower range of accessible drift velocities, the residence time of electrons in the resonance cell approaches 0.1 sec

Maximum power point tracker Patent

Power point tracker for maintaining optimal output voltage of power sourc

AN ALTERNATIVE APPROACH TO DETERMINING THE ELASTICITY OF EXCESS DEMAND FACING THE UNITED STATES

The United States embarked on a policy assuming excess demands for commodities are elastic. Some analysts question the success of that policy and argue that excess demands for farm commodities are inelastic. The controversy is deepened because the two traditional techniques for determining excess demand elasticities yield opposing estimates. We use an alternative technique based on observed variation in commodity prices, production, and use. The point estimates show excess demands for wheat, coarse grains, soybeans, rice, and cotton are elastic. However, a one-sided bootstrap test cannot reject the null hypothesis that the excess demands for wheat, coarse grains, and soybeans are inelastic.Demand and Price Analysis,

Exploring taboo issues in professional sport through a fictional approach

While the need to consider life course issues in elite sport research and practice is increasingly recognised, some experiences still seem to be considered too dangerous to explore. Consequently, stories of these experiences are silenced and the ethical and moral questions they pose fail to be acknowledged, understood or debated. This paper presents an ethnographic fiction through which we explore a sensitive set of experiences that were uncovered during our research with professional sportspeople. Through a multi‐layered reconstruction, the story reveals the complex, but significant, relationships that exist between identity, cultural narratives and embodied experiences. After the telling we consider how the story has stimulated reflective practice among students, researchers and practitioners. While there are risks involved in writing and sharing taboo stories, the feedback we have received suggests that storytelling can be an effective pedagogical tool in education and professional development

Learning Style Diversity in Post –Secondary Distance Education

During the fall semester of 2005, 153 university graduate students’ preferred learning styles were measured with the Kolb Learning Style Inventory, online version 3.1. The primary findings of the study indicated all of the learning styles and processes described by Kolb were represented in the distance learning population and suggested distance and residential learners uniquely engage the learning process. Biblical references were discussed with respect to the uniqueness displayed by study participants

Higher Order Modulation Equations for a Boussinesq Equation

In order to investigate corrections to the common KdV approximation to long waves, we derive modulation equations for the evolution of long wavelength initial data for a Boussinesq equation. The equations governing the corrections to the KdV approximation are explicitly solvable and we prove estimates showing that they do indeed give a significantly better approximation than the KdV equation alone. We also present the results of numerical experiments which show that the error estimates we derive are essentially optimal

Simultaneous occurrence of sliding and crossing limit cycles in piecewise linear planar vector fields

In the present study we consider planar piecewise linear vector fields with two zones separated by the straight line $x=0$. Our goal is to study the existence of simultaneous crossing and sliding limit cycles for such a class of vector fields. First, we provide a canonical form for these systems assuming that each linear system has center, a real one for $y<0$ and a virtual one for $y>0$, and such that the real center is a global center. Then, working with a first order piecewise linear perturbation we obtain piecewise linear differential systems with three crossing limit cycles. Second, we see that a sliding cycle can be detected after a second order piecewise linear perturbation. Finally, imposing the existence of a sliding limit cycle we prove that only one adittional crossing limit cycle can appear. Furthermore, we also characterize the stability of the higher amplitude limit cycle and of the infinity. The main techniques used in our proofs are the Melnikov method, the Extended Chebyshev systems with positive accuracy, and the Bendixson transformation.Comment: 24 pages, 7 figure