10,225 research outputs found
Up-date of traveling wave tube improvements
A brief survey is presented of areas of progress on traveling wave tube designs. Data demonstrates the effect of multistage depressed collectors, the design of which is made possible by powerful NASA computer programs. Other topics include beam refocusing, RF circuit losses, and cathode testing
Fundamental Studies Connected with Electrochemical Energy Storage
Papers are presented which deal with electrochemical research activities. Emphasis is placed on electrochemical energy storage devices. Topics discussed include: adsorption of dendrite inhibitors on zinc; proton discharge process; electron and protron transfer; quantum mechanical formulation of electron transfer rates; and theory of electrochemical kinetics in terms of two models of activation; thermal and electrostatic
We thought it might encourage participation.â Using lottery incentives to improve LibQUAL+(TM) response rates among students
Libraries deploying the LibQUAL+âą survey can offer a lottery incentive and many do in the hope of increasing response rates. Other libraries may be prohibited from offering one because of Institutional Review Board restrictions, as is the case at [institution name]. We wanted to discover why libraries offer lottery incentives and what kinds and if they believe these incentives have a positive impact on their response rates. The responding libraries hold a general belief that lottery incentives are effective but base this on feeling rather than research. We examine what the literature says about lottery incentives and student populations
Structural and Non-Structural Alternatives for Accommodating Larger Floods at Dams
This paper provides an overview of structural and non-structural alternatives for accommodating larger floods at dams. The first two alternatives discussed, raising the height of the project and/or lowering the reservoir pool, can be used to prevent overtopping by increasing the available floodwater detention storage in the reservoir. Data gathered by an ASCE task committee survey on modifications that include increased storage by raising project height are summarized and discussed. The third alternative discussed, early warning systems, can provide a low cost alternative to structural modifications. Case studies for the warning systems at the Santee Cooper North Dam and the TVA Blue Ridge Dam are presented
The germs inside me: Pediatric patients\u27 conceptualization of illness and regulation of emotions during hospitalization
The transition into a medical setting can be difficult for children under the age of 18. Previous research has identified a child\u27s capacity to construct accurate representations of illness, in addition to the construction and application of adaptive strategies to modify emotional arousal, as significant predictors of successful adjustment to a medical environment. Preexisting research has neglected to investigate the constructs of illness conceptualization and regulatory systems of emotions. Using a sample of 26 pediatric patients and 26 adult informants, the current study explored the complex relationship between emotional regulation and the conceptualization of illness among children, from the ages of three to five, in the management of a hospital setting. Measures of inhibition, attentional shift and inhibitory self-control were significantly and negatively related to general illness conceptualization. In addition, the study investigated the implications of increased exposure to hospitalization on pediatric patients\u27 development of health-related knowledge and strategies to regulate emotional arousal in early childhood. Contrary to prediction, children characterized as experiencing frequent admittances to a medical setting attained significantly higher means scores, reflecting poor aptitude, on measures of attentional shift, emotional control, and flexibility. The present investigation validates the necessity of respective therapeutic models to appropriately intervene for vulnerable, medically fragile populations
alpha-nucleus potentials for the neutron-deficient p nuclei
alpha-nucleus potentials are one important ingredient for the understanding
of the nucleosynthesis of heavy neutron-deficient p nuclei in the astrophysical
gamma-process where these p nuclei are produced by a series of (gamma,n),
(gamma,p), and (gamma,alpha) reactions. I present an improved alpha-nucleus
potential at the astrophysically relevant sub-Coulomb energies which is derived
from the analysis of alpha decay data and from a previously established
systematic behavior of double-folding potentials.Comment: 6 pages, 3 figures, accepted for publication in Phys. Rev.
Improved traveling wave tubes
After a brief description of how a typical TWT works, multi-stage depressed collectors (MDC) are discussed. A quick method for computing the expected efficiency of a well engineered TWT is outlined to aid in estimating power supply needs. Applications of improved TWTs and a new power supply are suggested
Cut-rose production in response to planting density in two contrasting cultivars
Growing in lower planting density, rose plants produce more assimilates, which can be used to produce more and/or heavier flowering shoots. The effect of planting density was investigated during a period including the first five flowering flushes of a young crop. In a heated greenhouse two cut-rose cultivars were grown under bent canopy management. âAkitoâ on own-roots and âIliosâ on âNatal Briarâ rootstock were planted with densities of 8 and 4 plants per m2. Starting at the end of June 2007, flowering shoots were harvested over a time span of eight months. Based on âflowering flushesâ, times of high harvest rate, the harvesting time span could be divided into five consecutive periods, each including one flush. The cultivars showed contrasting responses to planting density. In the first three periods the response in âIliosâ was extraordinary, because at low density plants did not produce more flowering shoots, as would be expected. However, the response in shoot fresh weight was larger for âIliosâ than for âAkitoâ, 35% compared to 21% over the entire study period. The results imply that there was a genetic difference in the effect of assimilate availability and/or local light environment. During the first three periods, these factors can not have influenced shoot number in âIliosâ, while they did in âAkitoâ. It is suggested that decreases of assimilate availability in winter caused the shoot number response to emerge for âIliosâ later on
Science is perception: what can our sense of smell tell us about ourselves and the world around us?
Human sensory processes are well understood: hearing, seeing, perhaps even tasting and touchâbut we do not understand smellâthe elusive sense. That is, for the others we know what stimuli causes what response, and why and how. These fundamental questions are not answered within the sphere of smell science; we do not know what it is about a molecule that ⊠smells. I report, here, the status quo theories for olfaction, highlighting what we do not know, and explaining why dismissing the perception of the input as âtoo subjectiveâ acts as a roadblock not conducive to scientific inquiry. I outline the current and new theory that conjectures a mechanism for signal transduction based on quantum mechanical phenomena, dubbed the âswipe cardâ, which is perhaps controversial but feasible. I show that such lines of thinking may answer some questions, or at least pose the right questions. Most importantly, I draw links and comparisons as to how better understanding of how small (10âs of atoms) molecules can interact so specially with large (10â000âs of atoms) proteins in a way that is so integral to healthy living. Repercussions of this work are not just important in understanding a basic scientific tool used by us all, but often taken for granted, it is also a step closer to understanding generic mechanisms between drug and receptor, for example
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