Thermochemical energy storage for a lunar base

A thermochemical solar energy storage concept involving the reversible reaction CaO + H2O yields Ca(OH)2 is proposed as a power system element for a lunar base. The operation and components of such a system are described. The CaO/H2O system is capable of generating electric power during both the day and night. Mass of the required amount of CaO is neglected since it is obtained from lunar soil. Potential technical problems, such as reactor design and lunar soil processing, are reviewed

"Economics in Context: The Need for a New Textbook"

economics education, textbooks, economic theory

X-ray induced persistent photoconductivity in Si-doped Al0.35_{0.35}Ga0.65_{0.65}As

We demonstrate that X-ray irradiation can be used to induce an insulator-metal transition in Si-doped Al$_{0.35}$Ga$_{0.65}$As, a semiconductor with {\it DX} centers. The excitation mechanism of the {\it DX} centers into their shallow donor state was revealed by studying the photoconductance along with fluorescence. The photoconductance as a function of incident X-ray energy exhibits an edge both at the Ga and As K-edge, implying that core-hole excitation of Ga and As are efficient primary steps for the excitation of {\it DX} centers. A high quantum yield ($\gg 1$) suggests that the excitation is indirect and nonlocal, due to secondary electrons, holes, and fluorescence photons.Comment: 3 pages of text, 6 figures. An error in Fig.5 was detected, so we corrected i

A Tropical Fruit Comes to Iowa

The fruit of this new annual garden plant lends itself to many different food uses either raw or cooked. Developed in Guatemala but adapted to Iowa and the Midwest, seed of the Mayan husk tomato now is available

A time lens for high resolution neutron time of flight spectrometers

We examine in analytic and numeric ways the imaging effects of temporal neutron lenses created by traveling magnetic fields. For fields of parabolic shape we derive the imaging equations, investigate the time-magnification, the evolution of the phase space element, the gain factor and the effect of finite beam size. The main aberration effects are calculated numerically. The system is technologically feasible and should convert neutron time of flight instruments from pinhole- to imaging configuration in time, thus enhancing intensity and/or time resolution. New fields of application for high resolution spectrometry may be opened.Comment: 8 pages, 11 figure

Interpersonal Problem Areas and Onset of Panic Disorder

Background: Numerous studies indicate that stressful life events are key precipitants of psychological disturbances. Severe stress often precedes the onset or exacerbation of illness in vulnerable individuals and may be of primary importance in the genesis of some mental disorders. Several authors have suggested that major life events play a role in the development of panic-related symptoms. The aim of this study was to examine the presence of stressful life events, in particular events focused in the interpersonal psychotherapy problem areas (grief, role disputes, role transitions, interpersonal deficits), in patients suffering from panic disorder. Methods: We interviewed 55 patients suffering from panic disorder, with or without agoraphobia, in accordance with the diagnostic criteria specified in MINI PLUS. The panic attack profile was evaluated with the Panic Attack and Anticipatory Anxiety Scale. We assessed the ability to adapt to and derive satisfaction from the social environment with the Social Adjustment Scale Self Report and interpersonal problems with Interpersonal Questionnaire. Results: Using the Interpersonal Questionnaire we found that all subjects had had relevant interpersonal problems in the year preceding the onset of PD: 92.7% had experienced a role transition, 85.5% interpersonal deficits, 74.5% a role dispute and 38.2% had suffered the loss of a relative or significant other. These results were confirmed by Paykel's scale, on which the whole sample reported a high frequency of life events in the 6 months before onset of illness. These preliminary data suggest a rationale for the therapeutic strategies of interpersonal psychotherapy in individuals with panic disorder