21,989 research outputs found

    A Computer Program for Population Analysis

    Get PDF
    A computer program for population analysis has been developed that is simply written, but relatively sophisticated. It consists of three parts: computation and tabulation of data, statistical analysis and plotting. The program can be understood readily by computation center personnel and requires a minimum of modification for use in most facilities. Once the program is instituted, an instructor need only have knowledge of the format requirements to use it. Lack of a programming background need not prevent an instructor from using the computer for population analysis

    Fleming's bound for the decay of mixed states

    Full text link
    Fleming's inequality is generalized to the decay function of mixed states. We show that for any symmetric hamiltonian hh and for any density operator ρ\rho on a finite dimensional Hilbert space with the orthogonal projection Π\Pi onto the range of ρ\rho there holds the estimate \Tr(\Pi \rme^{-\rmi ht}\rho \rme^{\rmi ht}) \geq\cos^{2}((\Delta h)_{\rho}t) for all real tt with (Δh)ρtπ/2.(\Delta h)_{\rho}| t| \leq\pi/2. We show that equality either holds for all tRt\in\mathbb{R} or it does not hold for a single tt with 0<(Δh)ρtπ/2.0<(\Delta h)_{\rho}| t| \leq\pi/2. All the density operators saturating the bound for all tR,t\in\mathbb{R}, i.e. the mixed intelligent states, are determined.Comment: 12 page

    Mechanical and Chemical Control of Smooth Cordgrass in Waillapa Bay, Washington

    Get PDF
    We evaluated four methods to control smooth cordgrass (Spartina alterniflora Loisel), hereafter spartina, in Willapa Bay, Washington: mowing, mowing plus herbicide combination, herbicide only for clones, and aerial application of herbicide for meadows. (PDF has 7 pages.

    Band structure analysis of the conduction-band mass anisotropy in 6H and 4H SiC

    Full text link
    The band structures of 6H and 4H SiC calculated by means of the FP-LMTO method are used to determine the effective mass tensors for their conduction-band minima. The results are shown to be consistent with recent optically detected cyclotron resonance measurements and predict an unusual band filling dependence for 6H-SiC.Comment: 5 pages including 4 postscript figures incorporated with epsfig figs. available as part 2: sicfig.uu self-extracting file to appear in Phys. Rev. B: Aug. 15 (Rapid Communications

    Transient excitation and data processing techniques employing the fast fourier transform for aeroelastic testing

    Get PDF
    The development of testing techniques useful in airplane ground resonance testing, wind tunnel aeroelastic model testing, and airplane flight flutter testing is presented. Included is the consideration of impulsive excitation, steady-state sinusoidal excitation, and random and pseudorandom excitation. Reasons for the selection of fast sine sweeps for transient excitation are given. The use of the fast fourier transform dynamic analyzer (HP-5451B) is presented, together with a curve fitting data process in the Laplace domain to experimentally evaluate values of generalized mass, model frequencies, dampings, and mode shapes. The effects of poor signal to noise ratios due to turbulence creating data variance are discussed. Data manipulation techniques used to overcome variance problems are also included. The experience is described that was gained by using these techniques since the early stages of the SST program. Data measured during 747 flight flutter tests, and SST, YC-14, and 727 empennage flutter model tests are included

    Recent flow visualization studies in the 0.3-m TCT

    Get PDF
    Light beams are altered by refractive index changes; flow induced refractive index changes provide the impetus for conventional visualization techniques such as schlieren and shadowgraph. Unfortunately effects related to the flow can be masked by refractive index inhomogeneities external to the test section. A simple shadowgraph scheme was used to assess the flow quality of the Langley 0.3 meter Transonic Cryogenic Tunnel. When the penetration tubes were evacuated the quality of the shadowgraph improved dramatically

    Photogrammetric technique for in-flight ranging of trailing vortices using entrained balloons

    Get PDF
    A method for experimentally determining the radial distance of a probe aircraft from a trailing vortex is described. The method relies on photogrammetric triangulation of targets entrained in the vortex core. The theory and preliminary testing were described using laboratory mock-ups. Solid state video cameras were to provide data at 300 Hz rates. Practical methods for seeding the vortex are under separate investigation and are not addressed

    Non-target Impacts to Eelgrass from Treatments to Control Spartina in Willapa Bay, Washington

    Get PDF
    Four methods to control the smooth cordgrass Spartina (Spartina alterniflora) and the footwear worn by treatment personnelat several sites in Willapa Bay, Washington were evaluatedto determine the non-target impacts to eelgrass (Zostera japonica). Clone-sized infestations of Spartina were treated bymowing or a single hand-spray application of Rodeo® formulatedat 480 g L-1acid equivalence (ae) of the isopropylaminesalt of glyphosate (Monsanto Agricultural Co., St. Louis, MO;currently Dow AgroSciences, Indianapolis, IN) with the nonionic surfactant LI 700® (2% v/v) or a combination of mowing and hand spraying. An aerial application of Rodeo® with X-77 Spreader® (0.13% v/v) to a 2-ha meadow was also investigated. Monitoring consisted of measuring eelgrass shoot densities and percent cover pre-treatment and 1-yr post-treatment. Impacts to eelgrass adjacent to treated clones were determined 1 m from the clones and compared to a control 5-m away. Impacts from footwear were assessed at 5 equidistant intervals along a 10-m transect on mudflat and an untreated control transect at each of the three clone treatment sites. Impacts from the aerial application were determined by comparing shoot densities and percent cover 1, 3 and 10 m from the edge of the treated Spartina meadow to that at comparable distances from an untreated meadow. Methods utilized to control Spartina clones did not impact surrounding eelgrass at two of three sites. Decreases in shoot densities observed at the third site were consistent across treatments. Most impacts to eelgrass from the footwear worn by treatment personnel were negligible and those that were significant were limited to soft mud substrate. The aerial application of the herbicide was associated with reductions in eelgrass (shoot density and percent cover) at two of the three sampling distances, but reductions on the control plot were greater. We conclude that the unchecked spread of Spartina is a far greater threat to the survival and health of eelgrass than that from any of the control measures we studied. The basis for evaluating control measures for Spartina should be efficacy and logistical constraints and not impacts to eelgrass. PDF is 7 pages
    corecore