6,278 research outputs found
Turning people into couch potatoes is not the cure for sports concussion
No abstract available
Modeling the electromagnetic properties of the SCUBA-2 detectors
SCUBA-2 is the next-generation replacement for SCUBA (Sub-millimetre Common
User Bolometer Array) on the James Clerk Maxwell Telescope. Operating at 450
and 850 microns, SCUBA-2 fills the focal plane of the telescope with
fully-sampled, monolithic bolometer arrays. Each SCUBA-2 pixel uses a
quarter-wave slab of silicon with an implanted resistive layer and backshort as
an absorber and a superconducting transition edge sensor as a thermometer. In
order to verify and optimize the pixel design, we have investigated the
electromagnetic behaviour of the detectors, using both a simple
transmission-line model and Ansoft HFSS, a finite-element electromagnetic
simulator. We used the transmission line model to fit transmission measurements
of doped wafers and determined the correct implant dose for the absorbing
layer. The more detailed HFSS modelling yielded some unexpected results which
led us to modify the pixel design. We also verified that the detectors suffered
little loss of sensitivity for off-axis angles up to about 30 degrees.Comment: 13 pages, 14 figures, SPIE Glasgow 21-25 June 2004, Conference 549
Cultural Manipulation for Higher Yields
By cultural manipulation we will mean, in a broad sense, everything a farmer might do to increase crop yields per hectare, after he decides what to plant and buys the seed. With this restriction we leave out the agricultural economist and the plant breeder. When we limit our interest to yields per hectare we introduce an element of area. This will include the crop canopy above the surface and the root system below it. Cultural manipulation also includes what the farmer might do to make best use of water, carbon dioxide, nitrogen, and essential mineral nutrients whether they occur naturally or otherwise. We will also include manipulations designed to make the most efficient use of radiant energy during the growing season. Finally, consideration of the length of the growing season introduces the concept of time as one of the objects of cultural manipulation. This is a vast subject from which we cannot hope to do more than select a few interesting points to discuss. To review the literature we would have to start with the most ancient findings of archaeology when cultural practices were more the concern of priests than of agronomists. Last year a third to a half of the papers published in the area of agronomy would come within our definition so there is still some interest in the subject. Dr. Clements wrote a review in the Annual Review of Plant Physiology recently containing 284 literature citations, one of which I noticed was a review of climatic influences on crop growth that itself contained 10,000 citations. When we speak of cultural practices we are talking about something that is big business in the agricultural field
Electronic spectra of simple main group inorganic and organometallic systems
The purpose underlying the researches described in this thesis is an attempt to understand the bonding and electronic structure of some simple inorganic and organometallic systems. The particular molecules
chosen for study were the Selenium containing linear triatomic species
OCSe, SCSe, CSeā and the main group metallocenes M(Cā
Hā
)n n = 1,
M = Tl & In ; n= 2, M =Pb, Sn &Hg.In all cases the technique of ultraviolet photoelectron spectroscopy was employed and the (vacuum) ultraviolet absorption spectra
of OCSe, SCSe & CSeā were also recorded. The major features of the
photoelectron spectra were interpreted as arising from ionization from
the filled valence levels obtained from simple schemes derived from
Mulliken-Hund molecular orbital theory3. The absorption spectra
were analysed in terms of transitions from these filled valence shell
orbitals to the various empty valence and atomic like Rydberg4 orbitals
of the molecule. In addition, weaker features in the photoelectron
spectra of CSeā and SCSe were attributed to formally forbidden one photon transitions involving simultaneous ionization and electronic
excitation
The Alaska Marriage Amendment: The Peopleās Choice on the Last Frontier
I Sverige beraĢknas 17 % av befolkningen ha en hoĢrselnedsaĢttning, vilket innebaĢr att det aĢr den vanligaste sensoriska funktionsnedsaĢttningen. Idag finns det en maĢngd studier som visar att hoĢrselnedsaĢttning aĢr relaterat till saĢmre psykisk haĢlsa. Acceptans av sin hoĢrselnedsaĢttning har visat sig vara positivt foĢr hoĢrselnedsatta och samvarierar med hjaĢlpsoĢkande. Acceptance and commitment therapy (ACT) aĢr en transdiagnostisk behandling daĢr psykopatologi antas bero paĢ en hoĢg grad av upplevelsemaĢssigt undvikande och fusion med tankar. MaĢlet i ACT aĢr att oĢka psykologisk flexibilitet daĢr acceptans aĢr en betydande komponent. Denna explorativa studie undersoĢkte foĢraĢndringsprocesser i ACT foĢr personer med hoĢrselnedsaĢttning daĢr utfallet var kaĢnslomaĢssig och social anpassning foĢr hoĢrselnedsaĢttningen (HHIE-S). De foĢraĢndringsprocesser som proĢvades var acceptans (HAQ), som tidigare visat paĢ medierande effekt foĢr ACT, samt tvaĢ alternativa foĢraĢndringsprocesser; self-efficacy (HSE-4) och upplevd stress (PSS-4). Behandlingen bestod av aĢtta internetadministrerade moduler givna med behandlarstoĢd daĢr veckovisa maĢtningar av foĢraĢndringsprocesser och utfall anvaĢndes. Studiens resultat visar att behandlingsgruppen upplevde marginellt signifikant mindre problem med kaĢnslomaĢssig och social anpassning foĢr hoĢrselnedsaĢttningen (HHIE-S). Studiens resultat pekar paĢ att hoĢrselrelaterad acceptans (HAQ) och self- efficacy (HSE-4) medierar behandlingens effekt paĢ deltagarnas kaĢnslomaĢssiga och sociala anpassning foĢr hoĢrselnedsaĢttning (HHIE-S). SaĢledes tillfoĢr denna studie ytterligare belaĢgg foĢr acceptans som foĢraĢndringsprocess i ACT. AĢven self-efficacy kan vara en intressant mediator att beakta i fortsatt forskning.
Water transport through (7,7) carbon nanotubes of different lengths using molecular dynamics
Non-equilibrium molecular dynamics simulations are used to investigate water transport through (7,7) CNTs, examining how changing the CNT length affects the internal flow dynamics. Pressure-driven water flow through CNT lengths ranging from 2.5 to 50 nm is simulated. We show that under the same applied pressure difference an increase in CNT length has a negligible effect on the resulting mass flow rate and fluid flow velocity. Flow enhancements over hydrodynamic expectations are directly proportional to the CNT length. Axial profiles of fluid properties demonstrate that entrance and exit effects are significant in the transport of water along CNTs. Large viscous losses in these entrance/exit regions lead into central ādevelopedā regions in longer CNTs where the flow is effectively frictionless
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