4,175 research outputs found

    On the politics of lapdogs, Jim's dog, and crittercams

    Get PDF

    Positive gaging system feasibility study Summary report, 15 May - 15 Nov. 1967

    Get PDF
    Radio frequency mass gaging technique model for particular spacecraft fuel and tank configuratio

    Narrow Line Cooling and Momentum-Space Crystals

    Full text link
    Narrow line laser cooling is advancing the frontier for experiments ranging from studies of fundamental atomic physics to high precision optical frequency standards. In this paper, we present an extensive description of the systems and techniques necessary to realize 689 nm 1S0 - 3P1 narrow line cooling of atomic 88Sr. Narrow line cooling and trapping dynamics are also studied in detail. By controlling the relative size of the power broadened transition linewidth and the single-photon recoil frequency shift, we show that it is possible to continuously bridge the gap between semiclassical and quantum mechanical cooling. Novel semiclassical cooling process, some of which are intimately linked to gravity, are also explored. Moreover, for laser frequencies tuned above the atomic resonance, we demonstrate momentum-space crystals containing up to 26 well defined lattice points. Gravitationally assisted cooling is also achieved with blue-detuned light. Theoretically, we find the blue detuned dynamics are universal to Doppler limited systems. This paper offers the most comprehensive study of narrow line laser cooling to date.Comment: 14 pages, 19 figure

    Studies to determine the feasibility of various techniques for measuring propellant mass aboard orbiting space vehicle. Volume 1 - Phase B Final report, 30 Jun. 1966 - 2 Jun. 1967

    Get PDF
    Feasibility study for using radio frequency resonance counting for measuring propellant mass aboard orbiting spacecraf

    Positive gaging system feasibility study Interim report, 15 May - 15 Nov. 1967

    Get PDF
    Fuel gage configuration for Apollo spacecraft and lunar module propellant tank

    Sensory and cognitive components of visual information acquisition.

    Get PDF

    Spectroscopy of the a^3\Sigma_u^+ state and the coupling to the X^1\Sigma_g^+ state of K_2

    Full text link
    We report on high resolution Fourier-transform spectroscopy of fluorescence to the a^3\Sigma_u^+ state excited by two-photon or two-step excitation from the X^1\Sigma_g^+ state to the 2^3\Pi_g state in the molecule K_2. These spectroscopic data are combined with recent results of Feshbach resonances and two-color photoassociation spectra for deriving the potential curves of X^1\Sigma_g^+ and a^3\Sigma_u^+ up to the asymptote. The precise relative position of the triplet levels with respect of the singlet levels was achieved by including the excitation energies from the X^1\Sigma_g^+ state to the 2^3\Pi_g state and down to the a^3\Sigma_u^+ state in the simultaneous fit of both potentials. The derived precise potential curves allow for reliable modeling of cold collisions of pairs of potassium atoms in their ^2S ground state

    False claims about false memory research

    Get PDF
    Pezdek and Lam [Pezdek, K. & Lam, S. (2007). What research paradigms have cognitive psychologists used to study “False memory,” and what are the implications of these choices? Consciousness and Cognition] claim that the majority of research into false memories has been misguided. Specifically, they charge that false memory scientists have been (1) misusing the term “false memory,” (2) relying on the wrong methodologies to study false memories, and (3) misapplying false memory research to real world situations. We review each of these claims and highlight the problems with them. We conclude that several types of false memory research have advanced our knowledge of autobiographical and recovered memories, and that future research will continue to make significant contributions to how we understand memory and memory errors

    Advertising\u27s Misinformation Effect

    Get PDF
    This research explores whether post-experience advertising alters information learned in a consumer\u27s direct experience. An advertising misinformation effect was obtained for colour memory of a previously seen candy bar wrapper upon both visual and verbal misinformation. However, the misleading visual information produced more ‘remember’ judgements than misleading verbal information. This advertising misinformation effect did not dissipate when the source was discredited. We found that such memory changes can be directly linked to consumer subjective judgements and choices when the misleading information is particularly salient. Not only do these findings constitute a novel generalizability of the misinformation effect, they also have implications for social policy research on deceptive advertising

    Ultracold collision properties of metastable alkaline-earth atoms

    Get PDF
    Ultra-cold collisions of spin-polarized 24Mg,40Ca, and 88Sr in the metastable 3P2 excited state are investigated. We calculate the long-range interaction potentials and estimate the scattering length and the collisional loss rate as a function of magnetic field. The estimates are based on molecular potentials between 3P2 alkaline-earth atoms obtained from ab initio atomic and molecular structure calculations. The scattering lengths show resonance behavior due to the appearance of a molecular bound state in a purely long-range interaction potential and are positive for magnetic fields below 50 mT. A loss-rate model shows that losses should be smallest near zero magnetic field and for fields slightly larger than the resonance field, where the scattering length is also positive.Comment: 4 pages, 4 figure
    • 

    corecore