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Sample records for pac perturbed angular

  1. Characterization of nanostructured HfO2 films using Perturbed Angular Correlation (PAC) technique

    NASA Astrophysics Data System (ADS)

    Cavalcante, F. H. M.; Gomes, M. R.; Carbonari, A. W.; Pereira, L. F. D.; Rossetto, D. A.; Costa, M. S.; Redondo, L. M.; Mestnik-Filho, J.; Saxena, R. N.; Soares, J. C.

    2010-06-01

    The hyperfine field at 181Ta lattice sites in nanostructured HfO2 thin films was studied by the Perturbed Angular Correlation (PAC) technique. Thin oxide films were deposited by Electron Beam Evaporation on a silicon substrate. The thickness of the films was ~100 nm and ~250 nm. Radioactive 181Hf nuclei were produced by neutron activation of the film samples in the Brazilian Research Reactor (IPEN IEA-R1) by the reaction 180Hf(n, γ)181Hf. PAC measurements were carried out after annealing at 1473 K. The PAC technique allows the determination of the electric field gradient (EFG) at the probe sites.

  2. Simulated models of inhomogeneous broadening in perturbed angular correlation spectroscopy (PAC)

    NASA Astrophysics Data System (ADS)

    Stufflebeam, Michael A.; Hodges, Jeffery A.; Evenson, William E.; Matheson, P.; Zacate, M. O.

    2007-10-01

    All real crystals have defects: missing atoms (vacancies), impurities, atoms out of place, etc. In perturbed angular correlation (PAC), these defects produce damping of the correlation signal in time and broadening of the frequency spectrum. This broadening is termed ``inhomogeneous broadening'' since it is due to the inhomogeneities (i.e. defects) in the crystal. We have simulated PAC spectra for various concentrations (0.1% to 5%) of distant randomly distributed defects plus a near-neighbor vacancy in simple cubic and face-centered cubic crystal structures. For every particular set of defects, the randomly distributed defects and the near-neighbor vacancy together produce a net electric field gradient (EFG), from which we obtain the PAC spectrum. We fit average PAC spectra to study the effects of defect concentration and crystal structure on inhomogeneous broadening as an aid to analyzing experimental data.

  3. Simulated models of perturbed angular correlation (PAC) spectroscopy in a 4-state+S system

    NASA Astrophysics Data System (ADS)

    Hodges, Jeffery A.; Stufflebeam, Michael A.; Evenson, William E.; Matheson, P.; Zacate, M. O.

    2007-10-01

    Cerium oxide has a cubic crystal structure. A vacancy in CeO2 can be trapped by a probe atom and hop among equivalent 1st or 2nd neighbor sites of the probe, producing a fluctuating electric field gradient (EFG) at the probe nucleus. We have simulated the perturbed angular correlation (PAC) spectrum due to such a changing EFG (4-state model), as well as the case with an additional static background EFG (4-state+S). We have studied the effect of changing the defect hopping rates on the resulting spectrum and the inferred hyperfine parameters. We have analyzed these data to determine experimental conditions under which nonequilibrium initial probe distributions can be detected by PAC.

  4. PAC (perturbed angular correlation) analysis of defect motion by Blume's stochastic model for I = 5/2 electric quadrupole interactions

    SciTech Connect

    Evenson, W.E. . Dept. of Physics and Astronomy); Gardner, J.A.; Wang, Ruiping . Dept. of Physics); Su, Han-Tzong ); McKale, A.G. )

    1990-01-01

    Using Blume's stochastic model and the approach of Winkler and Gerdau, we have computed-time-dependent effects on perturbed angular correlation (PAC) spectra due to defect motion in solids in the case of I = (5/2) electric quadrupole interactions. We report detailed analysis for a family of simple models: XYZ + Z'' models, in which the symmetry axis of an axial efg is allowed to fluctuate among orientations along x, y, and z axes, and a static axial efg oriented along the z axis is added to the fluctuating efgs. When the static efg is zero, this model is termed the XYZ'' model. Approximate forms are given for G{sub 2}(t) in the slow and rapid fluctuation regimes, i.e. suitable for the low and high temperature regions, respectively. Where they adequately reflect the underlying physical processes, these expressions allow one to fit PAC data for a wide range of temperatures and dopant concentrations to a single model, thus increasing the uniqueness of the interpretation of the defect properties. Application of the models are given for zirconia and ceria ceramics. 14 refs.

  5. (Perturbed angular correlations in zirconia ceramics)

    SciTech Connect

    Not Available

    1990-01-01

    This is the progress report for the first year of the currently-approved three year funding cycle. We have carried on a vigorous program of experimental and theoretical research on microscopic properties of zirconia and ceria using the Perturbed Angular Correlation (PAC) experimental technique. The experimental method was described in the original proposal and in a number of references as well as several of the technical reports that accompany this progress report.

  6. Inhomogeneous Broadening in Perturbed Angular Correlation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bunker, Austin; Adams, Mike; Hodges, Jeffery; Park, Tyler; Stufflebeam, Michael; Evenson, William; Matheson, Phil; Zacate, Matthew

    2009-10-01

    Our research concerns the effect of a static distribution of defects on the net electric field gradient (EFG) within crystal structures. Defects and vacancies perturb the distribution of gamma rays emitted from radioactive probe nuclei within the crystal. These defects and vacancies produce a net EFG at the site of the probe which causes the magnetic quadrupole moment of the nucleus of the probe to precess about the EFG. The net EFG, which is strongly dependent upon the defect concentration, perturbs the angular correlation (PAC) of the gamma rays, and is seen in the damping of the perturbation function, G2(t), in time and broadening of the spectral peaks in the Fourier transform. We have used computer simulations to study the probability distribution of EFG tensor components in order to uncover the concentration dependence of G2(t). This in turn can be used to analyze experimental PAC data and quantitatively describe properties of the crystal.

  7. Concentration dependence of inhomogeneous broadening in perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Moreno, Carlos; Hodges, Jeffery A.; Park, Tyler; Stufflebeam, Michael; Evenson, W.; Matheson, P.; Zacate, M. O.

    2008-10-01

    Since real crystals always include defects, the effect of the defects on crystal properties depends on how many defects are present, i.e. on defect concentration. In perturbed angular correlation (PAC), these defects produce damping of the correlation signal in time and broadening of the frequency spectrum. This ``inhomogeneous broadening'' depends quantitatively on defect concentration, so the size of the broadening in a PAC spectrum can be a measure of the concentration of defects. Using simulated PAC spectra and independent component analysis to obtain the probability distribution function for electric field gradient (EFG) components, we have found defect concentration-dependent parameters for the probability functions. This allows us to calculate broadened PAC spectra for any selected defect concentration. It also allows us to fit defect concentration from an experimental PAC spectrum. This work will be applied initially to broadened PAC data from β-Mn, Al-doped β-Mn, and Sr2RuO4.

  8. Simulated models of inhomogeneous broadening in perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Hodges, Jeffery A.; Park, Tyler; Stufflebeam, Michael; Evenson, W.; Matheson, P.; Zacate, M. O.

    2008-10-01

    All real crystals have defects such as impurities and vacancies which affect their properties. In perturbed angular correlation (PAC), these defects produce damping of the correlation signal in time and broadening of the frequency spectrum. This broadening is termed ``inhomogeneous broadening'' since it is due to the inhomogeneities (i.e. defects) in the crystal. We have simulated PAC spectra for various concentrations (0.1% to 15%) of randomly distributed defects with a near-neighbor vacancy in simple cubic and face-centered cubic crystal structures. For every particular set of defects, the randomly distributed defects and the near-neighbor vacancy together produce a net electric field gradient (EFG), from which we obtain the PAC spectrum. We then average PAC spectra to study the effects of defect concentration and crystal structure on inhomogeneous broadening as an aid to analyzing experimental data. This work will be applied initially to broadened PAC data from β-Mn, Al-doped β-Mn, and Sr2RuO4.

  9. Studying oxygen vacancies in ceramics by perturbed angular correlation spectroscopy

    SciTech Connect

    Su, Han-Tzong; Wang, Ruiping; Fuchs, H.; Gardner, J.A. . Dept. of Physics); Evenson, W.E. . Dept. of Physics); Sommers, J.A. )

    1990-01-01

    Perturbed angular correlation measurements in tetragonal and cubic zirconia and in ceria are described. A physically reasonable and self-consistent interpretation of these data implies that oxygen vacancies are trapped at a second neighbor position by Cd in tetragonal zirconia and by In in ceria. For Cd in tetragonal zirconia, the vacancy trap energy is found to be 0.44 eV, and the energy barrier between adjacent trap sites is approximately 0.8 eV. The activation energy of an oxygen vacancy hopping between trap sites around {sup 111}Cd in ceria is found to be 0.55 eV. The activation energy for oxygen vacancy hopping in cubic zirconia, as detected by {sup 181}Ta PAC, is about 1.0 eV and independent of the Y concentration. 12 refs., 4 figs.

  10. Perturbed angular correlation study of a nanostructured HfO2 film

    NASA Astrophysics Data System (ADS)

    Pasquevich, A. F.; Cavalcante, F. H. M.; Soares, J. C.

    The hyperfine field at 181Ta lattice sites in a nanostructured Hf02 thin film was studied by the perturbed angular correlation (PAC) technique. The thin oxide film was deposited by pulsed laser ablation on a silicon substrate kept at 673 K. The thickness was about 25 nm. The radioactive 181Hf ions were produced by neutron activation of the very thin film in the Portuguese research reactor by the reaction 180Hf(n,γ)181Hf. PAC measurements were carried out at room temperature after annealing at different temperatures up to 1,473 K in air. The PAC technique allows determining the electric field gradient at the 181Ta probe sites. The 181Ta isotopes appear in the sample as disintegration product of 181 Hf.

  11. Perturbed angular correlation study of a nanostructured HfO2 film

    NASA Astrophysics Data System (ADS)

    Pasquevich, A. F.; Cavalcante, F. H. M.; Soares, J. C.

    2007-09-01

    The hyperfine field at 181Ta lattice sites in a nanostructured HfO2 thin film was studied by the perturbed angular correlation (PAC) technique. The thin oxide film was deposited by pulsed laser ablation on a silicon substrate kept at 673 K. The thickness was about 25 nm. The radioactive 181Hf ions were produced by neutron activation of the very thin film in the Portuguese research reactor by the reaction 180Hf(n, γ)181Hf. PAC measurements were carried out at room temperature after annealing at different temperatures up to 1,473 K in air. The PAC technique allows determining the electric field gradient at the 181Ta probe sites. The 181Ta isotopes appear in the sample as disintegration product of 181Hf.

  12. Electric field gradients at indium sites in spinels measured by perturbed angular correlations

    NASA Astrophysics Data System (ADS)

    Pasquevich, A. F.

    2005-07-01

    The Electric Field Gradient (EFG) at 111Cd isotope (produced by the Electron Capture (EC) decay of 111In) has been measured using Perturbed Angular Correlations (PAC) technique in many spinels. In the present work, data arising from such experiments were collected. The experimental EFG values, obtained at room temperature, at the B site of normal spinels are compared with those calculated considering the monopole moment of the ions and the dipole polarization of the anions. This comparison allows the determination of the u-parameter, which gives the anion position in the lattice.

  13. Study of nanoconfigurations in Zircon-Mullite composites using perturbed angular correlations

    NASA Astrophysics Data System (ADS)

    Chain, Cecilia Y.; Pasquevich, Alberto F.; Rivas, Patricia C.; Martínez, Jorge A.; Caracoche, María C.; Rendtorff, Nicolás M.; Conconi, Maria S.; Aglietti, Esteban F.

    2010-06-01

    It has been already published that, at nanoscopic level, zircon exhibits wide regions of aperiodic material not detected by the ordinary techniques used to analyse the obtained product in the production of ceramic materials. In this paper it is reported how the Perturbed Angular Correlations (PAC) technique has assisted the interpretation of a mismatch between experiment and theoretical estimation of a mechanical property in some zircon-mullite composites. In fact, it has been proved that the difference observed between the calculated and the experimental value of the elastic modulus in composites of the form (1-x) ZrSiO4 - x 3Al2O3.2SiO2 (with x = 15, 25, 35 and 45 wt.%) behaves very similarly as the relative amount of aperiodic zircon determined by PAC. This result allows to re-interpret the mullite role during the materials preparation.

  14. Independent component analysis of inhomogeneous broadening in perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Stufflebeam, Michael; Hodges, Jeffery A.; Park, Tyler; Evenson, W.; Matheson, P.; Zacate, M. O.

    2008-10-01

    Independent component analysis (ICA) of electric field gradient (EFG) tensor components has proven useful in analysis of inhomogeneous broadening in perturbed angular correlation (PAC). We have simulated PAC spectra for various concentrations (0.1% to 15%) of randomly distributed defects with a near- neighbor vacancy in simple cubic and face-centered cubic crystal structures. In analyzing this simulation, we used ICA to transform the Vxx and Vzz EFG components to find a joint probability distribution function for the EFGs. ICA allowed us to separate the components and develop the joint probability function as a product of the probability distributions for two independent coordinates. Then we found the broadened G2(t) by integration over the joint probability distribution function. We have compared these results to simulated G2(t) functions, allowing us to analyze the concentration dependence of the broadened PAC spectrum. This work will be applied initially to broadened PAC data from β-Mn, Al-doped β-Mn, and Sr2RuO4.

  15. Finding probability distributions for electric field gradient components with inhomogeneous broadening in perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Park, Tyler; Adams, Mike; Bunker, Austin; Hodges, Jeffery; Stufflebeam, Michael; Evenson, William; Matheson, Phil; Zacate, Matthew

    2009-10-01

    Materials contain defects, which affect crystal properties such as damping of the correlation signal,G2(t), in time and broadening of the frequency spectrum in perturbed angular correlation (PAC) experiments. We attribute this inhomogeneous broadening (IHB) to the random static defects that produce a distribution of electric field gradients (EFGs). Our goal is to find a relationship between the amount of broadening and the concentration of defects. After simulating the EFGs from random configurations of defects, we map our results from the Vzz-Vxx plane to a coordinate system optimized for the EFG distribution through a Czjzek transformation, followed by a conformal mapping. From histograms in this space, we can define probability distribution functions with parameters that vary according to defect concentration. This allows us to calculate the broadened G2(t) spectrum for any concentration, and, in reverse, identify concentrations given a broadened G2(t) spectrum.

  16. Search for magnetic interaction in In doped AlN using perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Agarwal, Ishita; Kessler, Patrick; Vianden, Reiner

    2013-05-01

    The possible presence of a large magnetic field due to spin polarization of a Cd nucleus (decay product of 111In) at an Al substitutional site in AlN is investigated with perturbed angular correlation (PAC) spectroscopy. The PAC spectra of 111In/111Cd in AlN show two probe environments: a weak quadrupole interaction (quadrupole interaction constant, ν _Q^{ lattice} = 30 MHz) due to 111In probes at a defect free Al substitutional site and an unknown large interaction (ν _Q^{ complex} = 300 MHz) tentatively attributed to a nearest neighbour pair between 111In and a nitrogen vacancy (VN) aligned along the c-axis. Surprisingly, in density functional theory (DFT) calculations, such a large electric field gradient (EFG) could not be reproduced. However, an inclusion of spin polarization in the calculations indicates a strong magnetic field at 50 % of the 111In/111Cd site. An attempt to verify the presence of the strong magnetic field and to explain the origin of the strong interaction is made. Orientation measurements show, the large interaction is not characterised by a magnetic interaction and is predominantly due to the EFG. However, in the presence of an external magnetic field, the strong interaction probe environment becomes more uniform and the EFG increases by 10 %. This definitely hints towards some sort of magnetic interaction at the strong interaction probe site.

  17. Phase identification in the Cu-In-S system by γ-γ perturbed angular correlations

    NASA Astrophysics Data System (ADS)

    Brüssler, M.; Metzner, H.; Husemann, K.-D.; Lewerenz, H. J.

    1988-11-01

    Perturbed angular correlations (PAC's) of γ rays are applied to investigate the Cu-In-S system. The radioactive 111-111Cd tracers are incorporated in the metallic indium used as starting material for crystal growth. Cu1-xIn1+xS2 samples with varying Cu:In ratio (x=0.0, 0.03, 0.07, 0.10) were prepared and characterized by PAC's. The stoichiometric sample (x=0.0) shows cubic symmetry of the In site without tetragonal distortion. For all samples with In excess the signals of metallic In (vQ1=e2qQ/h=18 MHz, η1=0) and InS (vQ2=233 MHz, η2=0.15) appear. Consequently, a new line in the Gibb's phase triangle of the Cu-In-S system is determined. The fractions of the In and InS phases as a function of In excess are analyzed.

  18. Investigations of Zr-Ni intermetallic compounds by perturbed angular correlations

    NASA Astrophysics Data System (ADS)

    Dey, C. C.

    2013-09-01

    The hyperfine interactions experienced by 181Ta in ZrNi5 and Zr2Ni7 intermetallic compounds have been investigated by the perturbed angular correlation (PAC) technique. In ZrNi5, a strong electric quadrupole interaction (∼40%) with ωQ=72.0(1) Mrad/s, η=0.25(1), δ=0 at room temperature has been found due to the presence of Zr2Ni7 contaminating phase produced during sample preparation in the arc furnace. A weak quadrupole interaction of Zr2Ni7 (∼5%) with ωQ=65(1) Mrad/s, η=0.24(6), δ=0 has also been observed. The cubic component of ZrNi5 also has been observed (∼40% at room temperature) in this sample along with associated defect (15%). It is found that at 873 K, the cubic fraction increases to ∼54% at the cost of its defect fraction. No magnetic interaction in ZrNi5 has been observed which supports the earlier PAC results but rules out the result of strong magnetic ordering found from magnetization measurement. In Zr2Ni7, two regular fractions corresponding to two different crystallographic sites of Zr have been clearly identified with the parameters ωQ(1)=70.9(1) Mrad/s, η(1)=0.28(1), δ=1.3(3)% and ωQ(2)=64(1) Mrad/s, η(2)=0.34(8), δ=0 while contradictory results were reported from previous measurements.

  19. Mediolateral angular momentum changes in persons with amputation during perturbed walking.

    PubMed

    Sheehan, Riley C; Beltran, Eduardo J; Dingwell, Jonathan B; Wilken, Jason M

    2015-03-01

    Over 50% of individuals with lower limb amputation fall at least once each year. These individuals also exhibit reduced ability to effectively respond to challenges to frontal plane stability. The range of whole body angular momentum has been correlated with stability and fall risk. This study determined how lateral walking surface perturbations affected the regulation of whole body and individual leg angular momentum in able-bodied controls and individuals with unilateral transtibial amputation. Participants walked at fixed speed in a Computer Assisted Rehabilitation Environment with no perturbations and continuous, pseudo-random, mediolateral platform oscillations. Both the ranges and variability of angular momentum for both the whole body and both legs were significantly greater (p<0.001) during platform oscillations. There were no significant differences between groups in whole body angular momentum range or variability during unperturbed walking. The range of frontal plane angular momentum was significantly greater for those with amputation than for controls for all segments (p<0.05). For the whole body and intact leg, angular momentum ranges were greater for patients with amputation. However, for the prosthetic leg, angular momentum ranges were less for patients than controls. Patients with amputation were significantly more affected by the perturbations. Though patients with amputation were able to maintain similar patterns of whole body angular momentum during unperturbed walking, they were more highly destabilized by the walking surface perturbations. Individuals with transtibial amputation appear to predominantly use altered motion of the intact limb to maintain mediolateral stability. PMID:25797789

  20. Mediolateral angular momentum changes in persons with amputation during perturbed walking.

    PubMed

    Sheehan, Riley C; Beltran, Eduardo J; Dingwell, Jonathan B; Wilken, Jason M

    2015-03-01

    Over 50% of individuals with lower limb amputation fall at least once each year. These individuals also exhibit reduced ability to effectively respond to challenges to frontal plane stability. The range of whole body angular momentum has been correlated with stability and fall risk. This study determined how lateral walking surface perturbations affected the regulation of whole body and individual leg angular momentum in able-bodied controls and individuals with unilateral transtibial amputation. Participants walked at fixed speed in a Computer Assisted Rehabilitation Environment with no perturbations and continuous, pseudo-random, mediolateral platform oscillations. Both the ranges and variability of angular momentum for both the whole body and both legs were significantly greater (p<0.001) during platform oscillations. There were no significant differences between groups in whole body angular momentum range or variability during unperturbed walking. The range of frontal plane angular momentum was significantly greater for those with amputation than for controls for all segments (p<0.05). For the whole body and intact leg, angular momentum ranges were greater for patients with amputation. However, for the prosthetic leg, angular momentum ranges were less for patients than controls. Patients with amputation were significantly more affected by the perturbations. Though patients with amputation were able to maintain similar patterns of whole body angular momentum during unperturbed walking, they were more highly destabilized by the walking surface perturbations. Individuals with transtibial amputation appear to predominantly use altered motion of the intact limb to maintain mediolateral stability.

  1. Cd hyperfine interactions in DNA bases and DNA of mouse strains infected with Trypanosoma cruzi investigated by perturbed angular correlation spectroscopy and ab initio calculations.

    PubMed

    Petersen, Philippe A D; Silva, Andreia S; Gonçalves, Marcos B; Lapolli, André L; Ferreira, Ana Maria C; Carbonari, Artur W; Petrilli, Helena M

    2014-06-01

    In this work, perturbed angular correlation (PAC) spectroscopy is used to study differences in the nuclear quadrupole interactions of Cd probes in DNA molecules of mice infected with the Y-strain of Trypanosoma cruzi. The possibility of investigating the local genetic alterations in DNA, which occur along generations of mice infected with T. cruzi, using hyperfine interactions obtained from PAC measurements and density functional theory (DFT) calculations in DNA bases is discussed. A comparison of DFT calculations with PAC measurements could determine the type of Cd coordination in the studied molecules. To the best of our knowledge, this is the first attempt to use DFT calculations and PAC measurements to investigate the local environment of Cd ions bound to DNA bases in mice infected with Chagas disease. The obtained results also allowed the detection of local changes occurring in the DNA molecules of different generations of mice infected with T. cruzi, opening the possibility of using this technique as a complementary tool in the characterization of complicated biological systems.

  2. Linear force and moment equations for an annular smooth shaft seal perturbed both angularly and laterally

    NASA Technical Reports Server (NTRS)

    Fenwick, J.; Dijulio, R.; Ek, M. C.; Ehrgott, R.

    1982-01-01

    Coefficients are derived for equations expressing the lateral force and pitching moments associated with both planar translation and angular perturbations from a nominally centered rotating shaft with respect to a stationary seal. The coefficients for the lowest order and first derivative terms emerge as being significant and are of approximately the same order of magnitude as the fundamental coefficients derived by means of Black's equations. Second derivative, shear perturbation, and entrance coefficient variation effects are adjudged to be small.

  3. Low temperature structural modification in Rb2ZrF6: Investigations by perturbed angular correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Dey, S. K.; Dey, C. C.; Saha, S.

    2016-06-01

    Temperature dependent perturbed angular correlation (PAC) measurements in crystalline compounds Rb2ZrF6 and Cs2HfF6 have been performed in the temperature range 298-753 K. In Rb2ZrF6, four discrete quadrupole interaction frequencies have been observed at room temperature which correspond to four minor structural modifications. From previous measurements, on the other hand, two structural modifications of this compound were known. A displacive phase transition, probably, occurs at low temperature due to rotation of the ZrF62- octahedron and produces different structural modifications. From present measurements in Rb2ZrF6, two quadrupole interaction frequencies [ωQ=26.1(3) Mrad/s, η=0.55(2), δ=5(1)% and ωQ=148.7(3) Mrad/s, η=0.538(5), δ=1.2%] have been found at room temperature which were not found from previous studies. In Cs2HfF6, these new structural modifications have not been observed.

  4. Second order classical perturbation theory for atom surface scattering: Analysis of asymmetry in the angular distribution

    SciTech Connect

    Zhou, Yun Pollak, Eli; Miret-Artés, Salvador

    2014-01-14

    A second order classical perturbation theory is developed and applied to elastic atom corrugated surface scattering. The resulting theory accounts for experimentally observed asymmetry in the final angular distributions. These include qualitative features, such as reduction of the asymmetry in the intensity of the rainbow peaks with increased incidence energy as well as the asymmetry in the location of the rainbow peaks with respect to the specular scattering angle. The theory is especially applicable to “soft” corrugated potentials. Expressions for the angular distribution are derived for the exponential repulsive and Morse potential models. The theory is implemented numerically to a simplified model of the scattering of an Ar atom from a LiF(100) surface.

  5. On angularly perturbed Laplace equations in the unit ball of IR{sup n+2} and their distributional boundary values

    SciTech Connect

    Massopust, P.R.

    1997-08-01

    All solutions of an in its angular coordinates continuously perturbed Laplace-Beltrami equation in the open unit ball IB{sup n+2} {contained_in} IR{sup n+2}, n {ge} 1, are characterized. Moreover, it is shown that such pertubations yield distributional boundary values which are different from, but algebraically and topologically equivalent to, the hyperfunctions of Lions & Magenes. This is different from the case of radially perturbed Laplace-Beltrami operators (cf. [7]) where one has stability of distributional boundary values under such perturbations.

  6. Magnetic hyperfine field in antiferromagnetic RGa2 (R = Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er) studied by perturbed angular correlation spectroscopy using 111Cd

    NASA Astrophysics Data System (ADS)

    Cavalcante, F. H. M.; Pereira, L. F. D.; Cavalcante, J. T.; Saitovitch, H.; Carbonari, A. W.; Saxena, R. N.; Forker, M.

    2013-05-01

    The magnetic and electric hyperfine interactions of the nuclear probe Cd111 in the hexagonal antiferromagnetic rare earth-gallium RGa2 (R = Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, and Er) intermetallic compounds have been investigated by perturbed angular correlation (PAC) spectroscopy as a function of temperature. With the exception of R = Nd and Ho, the magnetic hyperfine field Bhf is roughly proportional to the spin projection (g - 1)J of the R constituent. However, in the group of the light rare earths, the variation of Bhf with (g - 1)J is much weaker than that for the heavy R constituents, in contrast to the trend reported for all rare earth intermetallics investigated up to now as well as to the trend of the magnetic ordering temperatures of RGa2. The orientation of the 4f spins relative to the c axis of RGa2 deduced from the angle between Bhf and the symmetry axis of the electric field gradient was found to be temperature independent and in agreement with the results of previous magnetization measurements. Except for SmGa2 where the hyperfine field shows an abrupt decrease near TN, the temperature dependence of Bhf(T) is consistent with second order phase transitions. The magnetic ordering temperatures deduced from Bhf(T) agree with magnetization and neutron diffraction results.

  7. Electric field gradients at 181Ta probe in ZrNi: Results from perturbed angular correlation and first-principles calculations

    NASA Astrophysics Data System (ADS)

    Dey, C. C.; Das, Rakesh; Srivastava, S. K.

    2015-07-01

    Results of temperature dependent perturbed angular correlation (PAC) measurements in the equiatomic ZrNi alloy have been reported for the first time using 181Hf probe. At room temperature, values of quadrupole frequency and asymmetry parameter for the major component (~80%) are found to be ωQ=26.8(4) Mrad/s, and η=0.413(7). The resulting electric field gradient comes out to be Vzz=2.99 ×1017 V/cm2 and this corresponds to the probe nuclei occupying the regular substitutional Zr sites. In ZrNi system, no magnetic interaction is observed down to 77 K indicating absence of any magnetism in this material. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) studies on an inactive but similarly prepared sample confirm the dominant presence of the orthorhombic ZrNi phase in the sample. A complementary density functional theory (DFT) calculation results in Vzz=-2.35×1017 V/cm2, η=0.46 at the 181Ta probe impurity site and zero magnetic moment on each atomic site, in close agreement with the experimental results. Furthermore, it is found that electric field gradient for the regular component follows a T3/2 temperature dependence between 77 and 353 K, beyond which it varies linearly with temperature.

  8. [Model of the perception of perturbed angular motion of the cockpit as part of pilot's information model].

    PubMed

    Azarskov, V N; Blokhin, L N; Burdin, V V; Voronin, L I

    1991-01-01

    This paper presents the method, algorithm and results of structural identification as a model of pilot's perception of perturbed angular motion of the cockpit and its transmission to the joystick as well as spectral density of the remnant corresponding to the transmission process. Assessments of scalar quasilinear and (more effective) multichannel models of pilot's functions are given. The assessments have been obtained for a single operator. They illustrate the potentials of this procedure.

  9. Electric field gradients of CeMIn5 (M= Co, Rh, Ir) heavy-fermion systems studied by perturbed angular correlations and ab initio electronic structure calculations

    NASA Astrophysics Data System (ADS)

    Forker, M.; Silva, P. R. J.; Cavalcante, J. T. P. D.; Cavalcante, F. H. M.; Ramos, S. M.; Saitovitch, H.; Baggio-Saitovitch, E.; Alonso, R.; Taylor, M.; Errico, L. A.

    2013-04-01

    The electric field gradient (EFG) at the highly dilute nuclear probe 111Cd in the heavy fermion systems CeMIn5, M= Co, Rh, and Ir and YCoIn5 has been investigated by perturbed angular correlation (PAC) measurements of the nuclear electric quadrupole interaction (QI) of 111Cd on In sites. Pure and Sn-doped single crystals prepared by In-flux synthesis and polycrystalline samples prepared by arc melting have been studied. The samples were doped with the PAC probe 111Cd by diffusion of the mother isotope 111In. In all samples, several fractions of 111Cd probe nuclei subject to different QI's have been observed, among them a large fraction of 111Cd in unreacted In metal. Detailed calculations of the EFG at In nuclei and at Cd probes on In sites of pure and Sn-doped CeMIn5 were preformed, using the full-potential augmented plane wave+local orbital (APW+lo) formalism and taking into account different variables such as the electronic structure of the hyperfine probes, probe induced structural distortions, and impurity doping. The excellent agreement between the predicted EFG's and the experimental results allows us to assign two of the observed EFG components to the lattice sites 1c and 4i of the CeMIn5 compounds and to explain the pronounced difference of the EFG at In and Cd probes on the same lattice position. Structural distortions induced by the Cd probe and Sn-doping were found to have little effect on the EFG at the Cd probes. We also show that the local spin density approximation (LSDA) and LDA+U calculations predict very similar equilibrium structures and EFG's at the In/Cd sites. The extension of the experiments and the calculations from CeMIn5 to YCoIn5 and LaCoIn5 have established that the influence of the 4f electrons on the EFG's at impurity sites is negligibly small.

  10. Effect of Ge substitution for Si on the magnetic hyperfine field in LaMn2Si2 compound measured by perturbed angular correlation spectroscopy with 140Ce as probe nuclei

    NASA Astrophysics Data System (ADS)

    Bosch-Santos, B.; Carbonari, A. W.; Cabrera-Pasca, G. A.; Costa, M. S.; Saxena, R. N.

    2013-05-01

    The effect of substitution of Ge for Si in LaMn2Si2 compound on the magnetic hyperfine field (Bhf) has been investigated by perturbed γ -γ angular correlation (PAC) spectroscopy using 140La(140Ce) as probe nuclei. This compound exhibits antiferromagnetism followed by a ferromagnetic ordering when temperature decreases. The behavior of the ferromagnetic transition when Ge gradually replaces Si, with concentrations of 20%, 40%, 80%, and 100% is discussed. PAC measurements were carried out in the temperature range from 15 K to 325 K. Results for LaMn2Si2 compound showed that the dependence of Bhf with temperature follows the expected behavior for the host magnetization and could be fitted by a Brillouin function for JMn = 5/2. However, the temperature dependence of Bhf for compounds when Si is gradually replaced by Ge showed a deviation from such a behavior, which gradually increases up to a strong deviation observed for LaMn2Ge2. This striking behavior was ascribed to the hybridization of d band of the host and f band of the Ce impurities, which is stronger when the unit cell volume increase as Si ions are substituted by Ge atoms.

  11. Interaction of ethanol with 111In-labelled membranes: evaluation by the perturbed angular correlation-sum peak ratio method.

    PubMed

    Jay, M; Woodward, M A

    1985-08-01

    The interaction of ethanol with erythrocyte ghosts and vesicles composed of brain lipid extracts labelled with indium-111 was studied using the sum peak ratio method of perturbed angular correlation measurements. Membranes from animals that were fed diets containing ethanol for 10 days demonstrated resistance to the decrease in sum peak ratio values observed in control animals. Thus, repeated administration of ethanol induces changes in the properties of biological membranes, possibly by altering phospholipid composition, which is reflected in the anisotropy of membrane-associated 111In-labelled nuclei as measured by sum peak ratios.

  12. 83mKr, a potentially powerful PAC probe

    NASA Astrophysics Data System (ADS)

    Arenz, M.; Vianden, R.

    2013-05-01

    In the decay of 83Rb to 83mKr and the subsequent decay to the 83Kr ground state a 553-9.4 keV γ- γ and a 17.85-9.4 keV e-- γ cascade are populated. The intermediate 9.4 keV 7/2 + state with a half-life of 154 ns is a perfect candidate for the application of the perturbed angular correlation (PAC) technique. Thus, it is possible to investigate the lattice environment of the implanted probes via the electric quadrupole interaction of the 9.4 keV 7/2 + state with the electric field gradient produced by the host lattices. Details of the production of this new PAC probe and planned measurements will be discussed.

  13. PAC spectroscopy of electronic ceramics

    SciTech Connect

    Gardner, J.A.; Wang, Ruiping; Schwenker, R. . Dept. of Physics); Evenson, W.E. . Dept. of Physics and Astronomy); Rasera, R.L. . Dept. of Physics); Sommers, J.A. )

    1991-01-01

    Dilute indium dopants in cerium oxides and YBa{sub 2}Cu{sub 3}O{sub x} have been studied by{sup 111}In/Cd Perturbed Angular Correlation (PAC) spectroscopy. By controlling oxygen vacancy concentration in the cerium oxides through doping or high-temperature vacuum annealing, we have found that indium always forms a defect complex unless the sample is doped to reduce greatly the oxygen vacancy concentration. Three different vacancy-associated complexes are found with concentrations that depend on doping and oxygen stoichiometry. Another defect complex occurs in samples having negligible vacancy concentration. At low temperatures, evidence is found of interaction with an electronic hole trapped by {sup 111}Cd after the radioactive decay of the {sup 111}In parent. In YBa{sub 2}Cu{sub 3}O{sub x} the indium substitutes preferentially at the Y site but has measurable probability of substitution in at least one of the two copper sites. A symmetry change near 650 {degree}C is consistent with the well-documented orthorhombic/tetragonal transition for samples in air or oxygen.

  14. PAC spectroscopy of electronic ceramics

    SciTech Connect

    Gardner, J.A.; Wang, Ruiping; Schwenker, R.; Evenson, W.E.; Rasera, R.L.; Sommers, J.A.

    1991-12-31

    Dilute indium dopants in cerium oxides and YBa{sub 2}Cu{sub 3}O{sub x} have been studied by{sup 111}In/Cd Perturbed Angular Correlation (PAC) spectroscopy. By controlling oxygen vacancy concentration in the cerium oxides through doping or high-temperature vacuum annealing, we have found that indium always forms a defect complex unless the sample is doped to reduce greatly the oxygen vacancy concentration. Three different vacancy-associated complexes are found with concentrations that depend on doping and oxygen stoichiometry. Another defect complex occurs in samples having negligible vacancy concentration. At low temperatures, evidence is found of interaction with an electronic hole trapped by {sup 111}Cd after the radioactive decay of the {sup 111}In parent. In YBa{sub 2}Cu{sub 3}O{sub x} the indium substitutes preferentially at the Y site but has measurable probability of substitution in at least one of the two copper sites. A symmetry change near 650 {degree}C is consistent with the well-documented orthorhombic/tetragonal transition for samples in air or oxygen.

  15. EFG Component Distribution Functions in Inhomogeneous Broadening in PAC Spectroscopy

    NASA Astrophysics Data System (ADS)

    Adams, Mike; Matheson, P.; Evenson, W. E.; Zacate, M. O.

    2010-10-01

    Perturbed Angular Correlation (PAC) spectroscopy is used to study the distribution and mobility of defects within crystals. The angular correlation of multiple gamma rays emitted from probe nuclei, affected by the net electric field gradient (EFG) in a probe's vicinity, are used to produce the PAC spectrum, G2(t). The distribution of EFGs from many random defects in a crystal, results in inhomogeneous broadening (IHB) of G2(t). Our EFG component probability distribution functions are found by summing 20,000 net EFGs, each found from taking a random distribution of vacancies of a particular concentration, combined with a single trapped vacancy in a near neighbor position to a probe nucleus. The derived EFG component distributions allow us to reconstruct the G2(t) as a function of defection concentration. The EFG component distribution functions are characterized by weighted sums of either Gamma, Lorenztian or Gaussian distributions. A systematic change in the type and number of distribution functions required to model IHB is apparent as defect concentration increases. In particular, the EFG distributions become increasingly skewed with increasing defect concentration. Results for the EFG components in simple cubic (SC), face-centered cubic (FCC) and body-centered cubic (BCC) lattices are presented.

  16. Spin fluctuation and local magnetism of isolated Fe impurities in Pd1-xVx alloys studied by time differential perturbed angular distribution spectroscopy

    NASA Astrophysics Data System (ADS)

    Mohanta, S. K.; Srivastava, S. K.; Mishra, S. N.

    2016-12-01

    The magnetic moment and spin fluctuation temperature of isolated Fe impurity atoms in Pd1-xVx (0 ≤ x ≤ 0.15) alloys have been studied by time differential perturbed angular distribution (TDPAD) technique. With increasing V content in Pd matrix, a large non-linear reduction of the local magnetic moment accompanied with an exponential increase of the spin fluctuation temperature TSF has been observed. At and beyond x = 0.12, the Fe atoms are found to be nonmagnetic. As an important new feature, TSF is observed to vary quadratically with composition dependent changes in host spin polarization.

  17. Phase quantification of mullite-zirconia and zircon commercial powders using PAC and XRD techniques

    NASA Astrophysics Data System (ADS)

    Rendtorff, Nicolás M.; Conconi, Maria S.; Aglietti, Esteban F.; Chain, Cecilia Y.; Pasquevich, Alberto F.; Rivas, Patricia C.; Martínez, Jorge A.; Caracoche, María C.

    2010-06-01

    The short range technique of the Perturbed Angular Correlation (PAC) and x-ray diffraction (Rietveld) methods have been employed to determine the phase content in commercial mullite-zirconia and zircon raw materials that are ordinarily used to produce ceramic materials. The PAC technique, which probes zirconium-containing compounds at nanoscopic level, showed that zircon contains crystalline ZrSiO4 and an important amount of a structurally distorted zircon, which is also observed accompanying monoclinic zirconia in mullite-zirconia. This particular zircon phase was not detected by the long range x-ray diffraction-Rietveld technique. After an annealing treatment, important changes in crystalline contents of the powders allow confirming, by the x-ray diffraction-Rietveld method, the preexistence of this particular zircon phase. This fact must be taken into account when preparing multicomposites based on the present raw materials.

  18. PACS: next generation

    NASA Astrophysics Data System (ADS)

    Parikh, Ashesh; Mehta, Nihal

    2015-03-01

    In this paper, we propose a web-based framework for traditional PACS that has the potential to revolutionize the management and display of medical images while simultaneously decreasing the cost of deployment. Specifically, we demonstrate that all the tools to replace traditional PACS are finally available to make the transition to the internet. In addition, web-based solutions over capabilities that go well beyond traditional PACS.

  19. Magnetic behavior of La-doped Fe3O4 studied by perturbed angular correlation spectroscopy with 111Cd and 140Ce

    NASA Astrophysics Data System (ADS)

    Matos, I. T.; Bosch-Santos, B.; Cabrera-Pasca, G. A.; Carbonari, A. W.

    2015-05-01

    In this paper, the local magnetic properties of La-doped Fe3O4 (5% and 10%) bulk and Nanoparticles (NPs) samples were studied by measuring hyperfine interactions in a wide range of temperature from 10 to 900 K with perturbed γ-γ angular correlation spectroscopy using 111In(111Cd) and 140La(140Ce) as probe nuclei. Results for the temperature dependence of the magnetic hyperfine field (Bhf) for bulk and NP samples, pure and doped with La show that its behavior follows a second order Brillouin-like transition from which the Curie temperature (TC) was determined (TC ˜ 855 K). Results also show two different regions in NP samples: the core where a minor fraction of probe nuclei with well defined magnetic dipole frequency was observed and the shell where a major fraction with broad distributed electric quadrupolar frequency (surface effect in NP) was observed. The Verwey transition TV ˜ 120 K, due the order disorder phase, was also observed in all samples. The results are discussed in terms of the magnetic exchange interaction between Fe2+ and Fe3+ ions in the two regions of NP.

  20. Magnetic behavior of La-doped Fe{sub 3}O{sub 4} studied by perturbed angular correlation spectroscopy with {sup 111}Cd and {sup 140}Ce

    SciTech Connect

    Matos, I. T. Bosch-Santos, B.; Cabrera-Pasca, G. A.; Carbonari, A. W.

    2015-05-07

    In this paper, the local magnetic properties of La-doped Fe{sub 3}O{sub 4} (5% and 10%) bulk and Nanoparticles (NPs) samples were studied by measuring hyperfine interactions in a wide range of temperature from 10 to 900 K with perturbed γ-γ angular correlation spectroscopy using {sup 111}In({sup 111}Cd) and {sup 140}La({sup 140}Ce) as probe nuclei. Results for the temperature dependence of the magnetic hyperfine field (B{sub hf}) for bulk and NP samples, pure and doped with La show that its behavior follows a second order Brillouin-like transition from which the Curie temperature (T{sub C}) was determined (T{sub C} ∼ 855 K). Results also show two different regions in NP samples: the core where a minor fraction of probe nuclei with well defined magnetic dipole frequency was observed and the shell where a major fraction with broad distributed electric quadrupolar frequency (surface effect in NP) was observed. The Verwey transition T{sub V} ∼ 120 K, due the order disorder phase, was also observed in all samples. The results are discussed in terms of the magnetic exchange interaction between Fe{sup 2+} and Fe{sup 3+} ions in the two regions of NP.

  1. PACS on mobile devices

    NASA Astrophysics Data System (ADS)

    Parikh, Ashesh; Mehta, Nihal

    2015-03-01

    Recent advances in internet browser technologies makes it possible to incorporate advanced functionality of a traditional PACS for viewing DICOM medical images on standard web browsers without the need to pre-install any plug-ins, apps or software. We demonstrate some of the capabilities of standard web browsers setting the stage for a cloud-based PACS.

  2. Perturbed Angular Correlation Study of the Static and Dynamic Aspects of Cadmium and Mercury Atoms Inside and Attached to a C60 Fullerene Cage

    NASA Astrophysics Data System (ADS)

    Das, Satyendra K.; Guin, Rashmohan; Banerjee, Debasish; Johnston, Karl; Das, Parnika; Butz, Tilman; Amaral, Vitor S.; Correia, Joao G.; Barbosa, Marcelo B.

    2014-11-01

    30 keV 111mCd and 50 keV 199mHg beams from ISOLDE were used to implant on preformed targets of C60 with a thickness of 1 mg cm-2. Endofullerene compounds, viz. 111mCd@C60 and 199mHg@C60 formed during implantation were separated by filtration through micropore filter paper followed by solvent extraction. Dried samples of the endofullerene compounds were counted for the time differential perturbed angular correlation (TDPAC) measurement using the coincidence of the 151 - 245 keV cascade of 111mCd and the 374 - 158 keV cascade of 199mHg on a six LaBr3(Ce) detector system coupled with digital electronics. The results for 111mCd@C60 indicate a single static component (27%) and a fast relaxing component (73%), the latter implying that the cadmium atom moves rapidly inside the cage at room temperature. The quadrupole interaction frequency and asymmetry parameter of the cadmium atom occupying the static site in C60 are wQ=8.21(36) Mrad s-1 and η = 0.41(9), respectively. The fast relaxation constant is 0.0031(4) ns-1. Similarly, mercury atoms also exhibit a single static and a fast component. The static site has a quadrupole frequency wQ=283.0(12.4) Mrad s-1 and η =0 with a fraction of 30%. The fast relaxation constant is 0.045(8) ns-1 with a fraction of 70%, very similar to that of cadmium.

  3. PACS image security server

    NASA Astrophysics Data System (ADS)

    Cao, Fei; Huang, H. K.

    2004-04-01

    Medical image security in a PACS environment has become a pressing issue as communications of images increasingly extends over open networks, and hospitals are currently hard-pushed by Health Insurance Portability and Accountability Act (HIPAA) to be HIPPA complaint for ensuring health data security. Other security-related guidelines and technical standards continue bringing to the public attention in healthcare. However, there is not an infrastructure or systematic method to implement and deploy these standards in a PACS. In this paper, we first review DICOM Part15 standard for secure communications of medical images and the HIPAA impacts on PACS security, as well as our previous works on image security. Then we outline a security infrastructure in a HIPAA mandated PACS environment using a dedicated PACS image security server. The server manages its own database of all image security information. It acts as an image Authority for checking and certificating the image origin and integrity upon request by a user, as a secure DICOM gateway to the outside connections and meanwhile also as a PACS operation monitor for HIPAA supporting information.

  4. Dynamic hyperfine interactions in 111In(111Cd)-doped ZnO semiconductor: PAC results supported by ab initio calculations

    NASA Astrophysics Data System (ADS)

    Muñoz, Emiliano L.; Mercurio, Marcio E.; Cordeiro, Moacir R.; Pereira, Luciano F. D.; Carbonari, Artur W.; Rentería, Mario

    2012-08-01

    In this work, we present results of Time-Differential γ-γ Perturbed-Angular-Correlations (PAC) experiments performed in 111Cd-doped ZnO semiconductor. The PAC technique has been applied in order to characterize the electric-field-gradient (EFG) tensor at (111In (EC)→) 111Cd nuclei located, as was later demonstrated, at defect-free cation sites of the ZnO host structure. The PAC experiments were performed in the temperature range of 77-1075 K. At first glance, the unexpected presence of low-intensity dynamic hyperfine interactions was observed, which were analyzed with a perturbation factor based on the Bäverstam and Othaz model. The experimental EFG results were compared with ab initio calculations performed with the Full-Potential Augmented Plane Wave plus local orbital (FP-APW+lo) method, in the framework of the Density Functional Theory (DFT), using the Wien2K code. The presence of the dynamic hyperfine interactions has been analyzed enlightened by the FP-APW+lo calculations of the EFG performed as a function of the charge state of the cell. We could correlate the large strength of the dynamic hyperfine interaction with the strong variation of the EFG due to changes in the electronic charge distribution in the Cd vicinity during the time-window of the PAC measurement. It was also revealed that the Cd impurity decays to a final stable neutral charge state (Cd2+) fast enough (in few ns) to produce the nearly undamped observed PAC spectra.

  5. Electric field gradient in nanostructured SnO2 studied by means of PAC spectroscopy using 111Cd or 181Ta as probe nuclei

    NASA Astrophysics Data System (ADS)

    Ramos, Juliana Marques; Martucci, Thiago; Carbonari, Artur Wilson; de Souza Costa, Messias; Saxena, Rajendra Narain; Vianden, Reiner

    2013-05-01

    Electric quadrupole interactions were studied in pure and Mn-doped powder samples and thin films of SnO2 using perturbed γγ angular correlation spectroscopy (PAC). The powder samples were prepared by Sol gel method and the thin film were prepared on the Si (100) substrate by sputtering technique using Sn in the oxygen atmosphere. The samples were characterized by x-ray diffraction, energy dispersive spectroscopy and scanning electron microscopy. The thickness of the film was 100 nm. The average particle size of the SnO2 powder samples was determined to be smaller than 60 nm. The radioactive 111In and 181Hf tracers were introduced in the powder samples during the sol gel chemical process. Radioactive 111In was implanted on the SnO2 thin films using the University of Bonn ion implanter (BONIS). PAC measurements were carried out in a four BaF2 detector spectrometer in the temperature range of 77-973 K for samples annealed at different temperatures. The PAC results for both nuclear probes show the presence of two electric quadrupole interactions. The major fractions in both cases correspond to the substitutional sites in the rutile phase of SnO2. The results are compared with previous PAC measurements.

  6. Magnetic vacancies in antiferromagnetic RAg compounds—A PAC study

    NASA Astrophysics Data System (ADS)

    Forker, M.; Fernández van Raap, M. B.; Pasquevich, A. F.

    2007-02-01

    Magnetic vacancies have been introduced into the ( π, π,0)-type antiferromagnetic structure of cubic RX compounds (R=rare earths, X=Ag, Cu) by replacing magnetic R by non-magnetic Y atoms. The magnetic hyperfine interaction resulting from this break of symmetry at the X-site has been investigated in R 1-xY xAg; R= Gd, Tb, Dy for Y concentrations 0⩽x⩽0.3 and in Dy 0.8Y 0.2Cu by perturbed angular correlation (PAC) spectroscopy with 111Cd as probe nucleus. The magnetic hyperfine field produced at 111Cd by one uncompensated nearest neighbor 4f spin is roughly proportional to the spin projection Bhf ∼0.9 ( g-1) J [T]. The temperature dependence of the magnetic hyperfine fields reflects the interaction of the 4f charge distribution with the crystal electric field. For R=Gd and Tb, the fraction of probe nuclei with one nearest Y neighbor is much smaller than expected for a statistical distribution of Y on R sites, suggesting that in these R 1-xY xAg compounds the 111In/ 111Cd probe atoms favor Ag sites with eight nearest R neighbors.

  7. Measurement of Aerosol and Cloud Particles with PACS and HARP Hyperangular Imaging Polarimeters

    NASA Astrophysics Data System (ADS)

    Martins, J.; Fernandez-Borda, R.; Remer, L. A.; Sparr, L.; Buczkowski, S.; Munchak, L. A.

    2013-12-01

    PACS is new hyper-angular imaging polarimeter for aeorosol and cloud measurerents designed to meet the requirements of the proposed ACE decadal survey mission. The full PACS system consists of three wide field of view (110deg cross track) telescopes covering the UV, VNIR, and SWIR spectral ranges with angular coverage between +55 deg forward to -55deg backwards. The angular density can be selected to cover up to 100 different viewing angles at selected wavelengths. PACS_VNIR is a prototype airborne instrument designed to demonstrate PACS capability by deploying just one of the three wavelength modules of the full PACS. With wavelengths at 470, 550, 675, 760 and 875nm, PACS_VNIR flew for the first time during the PODEX experiment in January/February 2013 aboard the NASA ER-2 aircraft. PACS SWIR (1.64, 1.88, 2.1, and 2.25um) is currently under construction and should be operational in the lab by Fall/2013. PACS_ UV has been fully designed, but is not yet under construction. During the PODEX flights PACS_VNIR collected data for aerosol and clouds over variable surface types including, water, vegetation, urban areas, and snow. The data is currently being calibrated, geolocated and prepared for the inversion of geophysical parameters including water cloud size distribution and aerosol microphysical parameters. The large density of angles in PACS allows for the characterization of cloudbow features in relatively high spatial resolution in a pixel to pixel basis. This avoids the need for assumptions of cloud homogeneity over any distance. The hyperangle capability also allows detailed observation of cloud ice particles, surface characterization, and optimum selection of the number of angles desired for aerosol retrievals. The aerosol and cloud retrieval algorithms under development for the retrieval of particle microphysical properties from the PACS data will be discussed in this presentation. As an extension of the PACS concept we are currently developing the HARP (Hyper-Angular

  8. Modified EFG Components and Their Joint pdf for Use in Modeling ihb in PAC

    NASA Astrophysics Data System (ADS)

    Adams, M.; Matheson, P.; Park, T.; Stufflebeam, M.; Hodges, J.; Evenson, W. E.; Zacate, M. O.

    2012-10-01

    Spectra of hyperfine interactions involving the electric field gradient tensor (EFG) are subject to broadening by statistical variations of EFG components. In perturbed angular correlation (PAC) experiments, the inhomogeneous broadening (ihb) of the G2(c,t) spectrum is produced by randomly distributed lattice defects of concentration, c. The EFG tensor has two independent components. The concentration dependence of ihb is determined by the joint probability distribution function (pdf) of these components. In typical PAC analyses, the independent coordinates are assumed to be Vzz and the asymmetry parameter η= (2Vxx+Vzz)/Vzz. However, the pdf P(c,Vzz,η) is not known, and in any case it is easy to show that Vzz and η are highly correlated, and not independent. We have found that the application of the Czjzek transformation [1], followed by a simple conformal mapping produces two, nearly independent EFG coordinates W1(c,Vzz,η) and W2(c,Vzz,η). The pdfs of each coordinate are readily characterized, and their product P(c,W1,W2)=P1(c,W1)P2(c,W2) forms an appropriate joint pdf that can be used to model ihb in a variety of situations. We show the application of this method by reporting results modeling the concentration dependence of ihb in various PAC models, for simple cubic (sc), face-centered cubic (fcc) and body-centered cubic (bcc) lattices. [4pt] [1] Czjzek, G. Hyperfine Interactions 14(1983) 189-194.

  9. PACS: effect on incidental findings.

    PubMed

    Green, Larissa

    2004-01-01

    Previous studies have addressed the increased volume of incidental findings when interpreting MRI lumbar spine studies after the implementation of a picture archiving and communication system (PACS). The purpose of this study is to confirm prior findings and contribute additional knowledge that supports the use of technology in complimenting the quality of patient care. Lumbar spine interpretations were reprinted from 900 studies and individually reviewed. These lumbar spine studies were performed on a 1.5-tesla magnet. Included were 300 consecutive lumbar spine reports over a two year period: four months prior to PACS introduction, four months during the transition to PACS, and four months post PACS implementation. Reports stating incidental findings were tabulated, along with the frequency patient gender, age, location (outpatient, inpatient or emergency room), reporting radiologist, specific finding and radiologist recommendations in each case were documented. The number of incidental findings increased from five pre-PACS to nine during the transition phase to PACS, followed by 11 post-PACS. This results in a maximum increase of 120 percent from pre- to post-PACS. The most common incidental findings include renal mass, cyst or lesions, aortic aneurysms and lymph node abnormalities. Statistical data confirms that the implementation of PACS into a radiology practice for MRI lumbar spine imaging appears to have a beneficial impact on the number of reported incidental findings and recommended follow-up studies.

  10. Induced Angular Momentum

    ERIC Educational Resources Information Center

    Parker, G. W.

    1978-01-01

    Discusses, classically and quantum mechanically, the angular momentum induced in the bound motion of an electron by an external magnetic field. Calculates the current density and its magnetic moment, and then uses two methods to solve the first-order perturbation theory equation for the required eigenfunction. (Author/GA)

  11. LOCAL MAGNETIC BEHAVIOR OF 54Fe in EuFe2As2 AND Eu0.5K0.5Fe2As2: MICROSCOPIC STUDY USING TIME DIFFERENTIAL PERTURBED ANGULAR DISTRIBUTION (TDPAD) SPECTROSCOPY

    NASA Astrophysics Data System (ADS)

    Mohanta, S. K.; Mishra, S. N.; Davane, S. M.; Layek, S.; Hossain, Z.

    2013-12-01

    In this paper, we report the time differential perturbed angular distribution measurements of 54Fe on a polycrystalline EuFe2As2 and Eu0.5K0.5Fe2As2. The hyperfine field and nuclear spin-relaxation rate are strongly temperature dependent in the paramagnetic state suggesting strong spin fluctuation in the parent compound. The local susceptibility show Curie-Weiss-like temperature dependence and Korringa-like relaxation in the tetragonal phase indicating the presence of local moment. In the orthorhombic phase, the hyperfine field behavior suggesting quasi two-dimensional magnetic ordering. The experimental results are in a good agreement with first-principle calculations based on density functional theory.

  12. Angular Scaling In Jets

    SciTech Connect

    Jankowiak, Martin; Larkoski, Andrew J.; /SLAC

    2012-02-17

    We introduce a jet shape observable defined for an ensemble of jets in terms of two-particle angular correlations and a resolution parameter R. This quantity is infrared and collinear safe and can be interpreted as a scaling exponent for the angular distribution of mass inside the jet. For small R it is close to the value 2 as a consequence of the approximately scale invariant QCD dynamics. For large R it is sensitive to non-perturbative effects. We describe the use of this correlation function for tests of QCD, for studying underlying event and pile-up effects, and for tuning Monte Carlo event generators.

  13. PACS support: the radiology approach.

    PubMed

    Hasley, Tom

    2002-01-01

    In 1999, Rex Healthcare, a 394-bed facility located in Raleigh, N.C., faced a growing problem. The radiology department was performing a total of 130,000 procedures a year, running out of space to store the film, and having trouble managing the file room. While the IT department was focused on the Y2K scare, radiology forged ahead with a plan to implement PACS on its own at Rex Hospital. Rex had installed a mini-PACS system for ultrasound in 1996, but there was no internal support for the system's hardware or software. Being the first in the area to implement PACS, Rex wasn't able to recruit anyone locally to support the system, so they decided to take two areas that PACS had a great impact on and use their own people. The director of radiology asked the RIS analyst and the Film Library manager, both of whom were registered technologists, to implement and support the PAC system. The key to PACS support is not computer knowledge, although it helps. The key is to understand the radiology department as a whole and the workflow from within, which makes it hard to fully support from an IT perspective. The current PACS team at Rex is composed of a PACS analyst, system support specialist and an electronic imaging center manager. When we went live with PACS, it was obvious that not all of the existing file room personnel would make the technology leap, which they realized themselves. We didn't push anybody out, but we did raise the bar of expectations. By redefining job descriptions and having the EITs (electronic imaging technologists) become more involved, increased respect was quite evident among the hospital staff. The clerks that once only hung and filed films are now troubleshooting CD burners, teaching physicians the PACS, and filming necessary exams. The final key to success is to take ownership of your system. By taking ownership, I mean that a PACS team should be established to do troubleshooting and first-line support, know the servers and application, and feel

  14. PACS photometer calibration block analysis

    NASA Astrophysics Data System (ADS)

    Moór, A.; Müller, T. G.; Kiss, C.; Balog, Z.; Billot, N.; Marton, G.

    2014-07-01

    The absolute stability of the PACS bolometer response over the entire mission lifetime without applying any corrections is about 0.5 % (standard deviation) or about 8 % peak-to-peak. This fantastic stability allows us to calibrate all scientific measurements by a fixed and time-independent response file, without using any information from the PACS internal calibration sources. However, the analysis of calibration block observations revealed clear correlations of the internal source signals with the evaporator temperature and a signal drift during the first half hour after the cooler recycling. These effects are small, but can be seen in repeated measurements of standard stars. From our analysis we established corrections for both effects which push the stability of the PACS bolometer response to about 0.2 % (stdev) or 2 % in the blue, 3 % in the green and 5 % in the red channel (peak-to-peak). After both corrections we still see a correlation of the signals with PACS FPU temperatures, possibly caused by parasitic heat influences via the Kevlar wires which connect the bolometers with the PACS Focal Plane Unit. No aging effect or degradation of the photometric system during the mission lifetime has been found.

  15. PCaPAC 2006 Proceedings

    SciTech Connect

    Pavel Chevtsov; Matthew Bickley

    2007-03-30

    The 6-th international PCaPAC (Personal Computers and Particle Accelerator Controls) workshop was held at Jefferson Lab, Newport News, Virginia, from October 24-27, 2006. The main objectives of the conference were to discuss the most important issues of the use of PCs and modern IT technologies for controls of accelerators and to give scientists, engineers, and technicians a forum to exchange the ideas on control problems and their solutions. The workshop consisted of plenary sessions and poster sessions. No parallel sessions were held.Totally, more than seventy oral and poster presentations as well as tutorials were made during the conference, on the basis of which about fifty papers were submitted by the authors and included in this publication. This printed version of the PCaPAC 2006 Proceedings is published at Jefferson Lab according to the decision of the PCaPAC International Program Committee of October 26, 2006.

  16. Preparation of PAC libraries. Final technical report

    SciTech Connect

    Pieter J. de Jong

    1997-12-31

    The goals of this project were to create P1 Artificial Chromosome (PAC) cloning vectors and use these vectors to generate, characterize, and distribute both human and mouse genomic PAC libraries to the scientific community.

  17. 24 CFR 891.725 - PAC administration.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false PAC administration. 891.725 Section... Individuals-Section 162 Assistance § 891.725 PAC administration. HUD is responsible for the administration of the PAC....

  18. 24 CFR 891.725 - PAC administration.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false PAC administration. 891.725 Section... Individuals-Section 162 Assistance § 891.725 PAC administration. HUD is responsible for the administration of the PAC....

  19. PACS and electronic health records

    NASA Astrophysics Data System (ADS)

    Cohen, Simona; Gilboa, Flora; Shani, Uri

    2002-05-01

    Electronic Health Record (EHR) is a major component of the health informatics domain. An important part of the EHR is the medical images obtained over a patient's lifetime and stored in diverse PACS. The vision presented in this paper is that future medical information systems will convert data from various medical sources -- including diverse modalities, PACS, HIS, CIS, RIS, and proprietary systems -- to HL7 standard XML documents. Then, the various documents are indexed and compiled to EHRs, upon which complex queries can be posed. We describe the conversion of data retrieved from PACS systems through DICOM to HL7 standard XML documents. This enables the EHR system to answer queries such as 'Get all chest images of patients at the age of 20-30, that have blood type 'A' and are allergic to pine trees', which a single PACS cannot answer. The integration of data from multiple sources makes our approach capable of delivering such answers. It enables the correlation of medical, demographic, clinical, and even genetic information. In addition, by fully indexing all the tagged data in DICOM objects, it becomes possible to offer access to huge amounts of valuable data, which can be better exploited in the specific radiology domain.

  20. COMPENDEX/TEXT-PAC: CIS.

    ERIC Educational Resources Information Center

    Standera, Oldrich

    This report evaluates the engineering information services provided by the University of Calgary since implementation of the COMPENDEX (tape service of Engineering Index, Inc.) service using the IBM TEXT-PAC system. Evaluation was made by a survey of the users of the Current Information Selection (CIS) service, the interaction between the system…

  1. RIS minus PACS equals film.

    PubMed

    Tellis, Wyatt M; Andriole, Katherine P; Jovais, Christopher S; Avrin, David E

    2002-01-01

    Web-based integration methods can be used to resolve a fundamental issue in the transition from film to a picture archiving and communication system (PACS): the identification of relevant prior studies only available on film. Even in the most ambitious conversions from a film-based environment to PACS, there are issues regarding prior studies not on PACS. Failure to compare with prior exams is one of the known risk factors for malpractice in radiology. While most commercial PACS systems today have some degree of RIS integration, knowledge of prior studies is usually limited to an awareness of studies in the PACS. On the other hand, most RIS systems today do not or cannot distinguish between studies on film and those in PACS. We made the observation, from a set theory perspective, that in general: Therefore we sought to create a system that would query both the RIS and PACS and reconcile the results using the above set operation. The query is initiated from a display station via the invocation of a Web browser installed on that station. The process of starting the browser is implemented using a scripting language provided by the workstation vendor, though the use of other mechanisms, such as the CCOW (Clinical Context Object Workgroup) or IHE (RSNA Integrated Healthcare Enterprise) interfaces, can be supported by this architecture. The medical record number, which identifies the current patient and is the primary parameter of the query, is passed as part of the URL (Universal Resource Locator) used to launch the browser. Once running, the browser connects to a Web server that hosts a JSP (Java Server Page) page that performs a DICOM query of the PACS and an HL7 query of the RIS, and then collates the results using the set operation described above. Both the DICOM and HL7 functionality are provided by Java-based toolkits developed in house. The results are returned to the client's browser as a standard HTML page with a tabular format detailing which studies are on

  2. RIS minus PACS equals film.

    PubMed

    Tellis, Wyatt M; Andriole, Katherine P; Jovais, Christopher S; Avrin, David E

    2002-01-01

    Web-based integration methods can be used to resolve a fundamental issue in the transition from film to a picture archiving and communication system (PACS): the identification of relevant prior studies only available on film. Even in the most ambitious conversions from a film-based environment to PACS, there are issues regarding prior studies not on PACS. Failure to compare with prior exams is one of the known risk factors for malpractice in radiology. While most commercial PACS systems today have some degree of RIS integration, knowledge of prior studies is usually limited to an awareness of studies in the PACS. On the other hand, most RIS systems today do not or cannot distinguish between studies on film and those in PACS. We made the observation, from a set theory perspective, that in general: Therefore we sought to create a system that would query both the RIS and PACS and reconcile the results using the above set operation. The query is initiated from a display station via the invocation of a Web browser installed on that station. The process of starting the browser is implemented using a scripting language provided by the workstation vendor, though the use of other mechanisms, such as the CCOW (Clinical Context Object Workgroup) or IHE (RSNA Integrated Healthcare Enterprise) interfaces, can be supported by this architecture. The medical record number, which identifies the current patient and is the primary parameter of the query, is passed as part of the URL (Universal Resource Locator) used to launch the browser. Once running, the browser connects to a Web server that hosts a JSP (Java Server Page) page that performs a DICOM query of the PACS and an HL7 query of the RIS, and then collates the results using the set operation described above. Both the DICOM and HL7 functionality are provided by Java-based toolkits developed in house. The results are returned to the client's browser as a standard HTML page with a tabular format detailing which studies are on

  3. Urological diagnosis using clinical PACS

    NASA Astrophysics Data System (ADS)

    Mills, Stephen F.; Spetz, Kevin S.; Dwyer, Samuel J., III

    1995-05-01

    Urological diagnosis using fluoroscopy images has traditionally been performed using radiographic films. Images are generally acquired in conjunction with the application of a contrast agent, processed to create analog films, and inspected to ensure satisfactory image quality prior to being provided to a radiologist for reading. In the case of errors the entire process must be repeated. In addition, the radiologist must then often go to a particular reading room, possibly in a remote part of the healthcare facility, to read the images. The integration of digital fluoroscopy modalities with clinical PACS has the potential to significantly improve the urological diagnosis process by providing high-speed access to images at a variety of locations within a healthcare facility without costly film processing. The PACS additionally provides a cost-effective and reliable means of long-term storage and allows several medical users to simultaneously view the same images at different locations. The installation of a digital data interface between the existing clinically operational PACS at the University of Virginia Health Sciences Center and a digital urology fluoroscope is described. Preliminary user interviews that have been conducted to determine the clinical effectiveness of PACS workstations for urological diagnosis are discussed. The specific suitability of the workstation medium is discussed, as are overall advantages and disadvantages of the hardcopy and softcopy media in terms of efficiency, timeliness and cost. Throughput metrics and some specific parameters of gray-scale viewing stations and the expected system impacts resulting from the integration of a urology fluoroscope with PACS are also discussed.

  4. An ontology for PACS integration.

    PubMed

    Kahn, Charles E; Channin, David S; Rubin, Daniel L

    2006-12-01

    An ontology describes a set of classes and the relationships among them. We explored the use of an ontology to integrate picture archiving and communication systems (PACS) with other information systems in the clinical enterprise. We created an ontological model of thoracic radiology that contained knowledge of anatomy, imaging procedures, and performed procedure steps. We explored the use of the model in two use cases: (1) to determine examination completeness and (2) to identify reference (comparison) images obtained in the same imaging projection. The model incorporated a total of 138 classes, including radiology orderables, procedures, procedure steps, imaging modalities, patient positions, and imaging planes. Radiological knowledge was encoded as relationships among these classes. The ontology successfully met the information requirements of the two use-case scenarios. Ontologies can represent radiological and clinical knowledge to integrate PACS with the clinical enterprise and to support the radiology interpretation process.

  5. Angular Momentum

    ERIC Educational Resources Information Center

    Shakur, Asif; Sinatra, Taylor

    2013-01-01

    The gyroscope in a smartphone was employed in a physics laboratory setting to verify the conservation of angular momentum and the nonconservation of rotational kinetic energy. As is well-known, smartphones are ubiquitous on college campuses. These devices have a panoply of built-in sensors. This creates a unique opportunity for a new paradigm in…

  6. Renormalized Lie perturbation theory

    SciTech Connect

    Rosengaus, E.; Dewar, R.L.

    1981-07-01

    A Lie operator method for constructing action-angle transformations continuously connected to the identity is developed for area preserving mappings. By a simple change of variable from action to angular frequency a perturbation expansion is obtained in which the small denominators have been renormalized. The method is shown to lead to the same series as the Lagrangian perturbation method of Greene and Percival, which converges on KAM surfaces. The method is not superconvergent, but yields simple recursion relations which allow automatic algebraic manipulation techniques to be used to develop the series to high order. It is argued that the operator method can be justified by analytically continuing from the complex angular frequency plane onto the real line. The resulting picture is one where preserved primary KAM surfaces are continuously connected to one another.

  7. Population Association of China (PAC).

    PubMed

    Xiong, Y

    1983-12-01

    In the past 3 years, the Population Association of China, an independent, academic, and nongovernment organization established in February 1981, organized demographers throughout China to tackle the population problems that emerged in the course of the nation's socioeconomic development. Thus, by organizing and promoting exchanges, the Association did help to push forward the vigorous development of population science. Now PAC has over 500 individuals and organized units as members. It has 90 council members and 19 permanent council members. Its annual tasks and research priorities are discussed and decided by the permanent council, and then implemented in various departments and localities by its council or association members. The Population Association has organized various academic activities among demographers to study the characteristics of different periods. 1983 is an important year for the reform of social and economic systems in China. The new situation and problems brought about by the reform are bound to affect the control of population growth. Consequently, the Association decided to emphasize the control of population growth in rural areas. At the same time, the Association advocated a style of study which required people to delve into the realities of life and to investigate and study these realities thoroughly. For this purpose, 3 discussions were either financed or authorized by the Association in a single year. At the symposiums, demographers and field workers, proceeding from their country's reality and by applying the Marxist point of view, tried to find effective solutions to the demographic problems. As a result, they produced a number of valuable academic reports. In the last few years, PAC played an important role in international academic activities and exchanges. Reviewing the past and looking ahead to the future, PAC will further unite China's demographers to make new contributions to the development of the country's population science

  8. Gamma Ray Emission Tomography and Angular Correlation Measurements to Study the Distribution and Binding Site of Selenium.

    NASA Astrophysics Data System (ADS)

    Dahni, Anwar

    Available from UMI in association with The British Library. The distribution of ^ {75}Se in tissue equivalent materials was investigated employing Gamma ray Emission Topography with a rectilinear scanner utilizing NaI(Tl) and BGO detectors. The reconstructed images, using Filtered Back Projection and Iterative techniques were presented in 2D colour and 3D representations. Using a lead collimator of aperture 1.5 x 20 mm and 70 length, the distribution of selenium with variation of volume and concentration was examined and clearly seen. Several corrections such as background, scattering, attenuation compensation and X-ray characteristic suppression, were performed to improve the quality of the images which was evaluated in terms of the fidelity factor. The possibility of quantifying an image was considered with regard to spatial resolution and least detectable concentration. The spatial resolution was measured using two small vials containing the same concentration of selenium, the value obtained was the same as the width of the collimator aperture. The value of the least detectable concentration of selenium however, was difficult to find, due to the many ambiguous factors involved. The binding site of selenium which is based on quadrupole interaction with the surrounding electric field, was investigated employing Perturbed Angular Correlation (PAC) experiments using NaI(Tl) and BaF_2 detectors. Using NaI(Tl) detectors, it was difficult to observe the perturbation, due to the poor time resolution. The BaF_2 detector according to the literature has a shorter light emission decay time constant (0.6 ns), suggested that a better time resolution than that found with the NaI(Tl) detectors could be obtained. A Perturbed Angular Correlation experiment employing BaF _2 detectors and a fast-slow coincidence system was set up. The time differential PAC of selenium in solution showed an unperturbed angular correlation pattern. The main problem is the very short half life of the

  9. CHILD-PACs Make for Happy Families.

    ERIC Educational Resources Information Center

    Patton, Mary Martin; Jones, Elizabeth

    1997-01-01

    Describes CHILD-PAC (Children's Hand-on Integrated Learning Discoveries--Parents as Co-Partners), a take-home learning center developed for infants and toddlers with disabilities and their parents to promote positive, interactive parent-child learning and playing. Three different CHILD-PACs designed to turn potentially difficult interaction times…

  10. Web-based PACS and EHR system

    NASA Astrophysics Data System (ADS)

    Parikh, Ashesh; Mehta, Nihal

    2015-03-01

    We demonstrate how a cloud-based PACS can exchange information with other medical systems, including other cloud-based PACS, to provide a comprehensive and integrated view of a patient's health record. Such a consolidated report will lead to improved patient care.

  11. Angular momentum

    NASA Astrophysics Data System (ADS)

    Shakur, Asif; Sinatra, Taylor

    2013-12-01

    The gyroscope in a smartphone was employed in a physics laboratory setting to verify the conservation of angular momentum and the nonconservation of rotational kinetic energy. As is well-known, smartphones are ubiquitous on college campuses. These devices have a panoply of built-in sensors. This creates a unique opportunity for a new paradigm in the physics laboratory. Many traditional physics experiments can now be performed very conveniently in a pedagogically enlightening environment while simultaneously reducing the laboratory budget substantially by using student-owned smartphones.

  12. Picture archiving and communications systems (PACS).

    PubMed

    Honeyman, J C; Frost, M M; Huda, W; Loeffler, W; Ott, M; Staab, E V

    1994-01-01

    Although there has been a recent increase in interest in picture archiving and communications systems (PACS) topics, little has been published to assist the non-technical person in understanding the complexities of the technologies required for a PACS implementation. This issue of Current Problems in Radiology defines each PACS component and explains why each is important in a system design. PACS installations at the University of Florida are used as examples to tie the concepts together. The infrastructure required for PACS consists of the information system interfaces, networks, and databases. Information system interfaces guarantee consistent patient data across all platforms and reduce labor requirements by eliminating duplicate data entry. Data networks move information from the originating location to users around the hospital, clinic, campus, city, or world. In the PACS environment, the data consist of patient and study information as well as images and information about these images. Databases organize the data from multiple sources into a coherent package that can be queried for many different purposes, such as retrieving images, reviewing patient and study information, studying practice statistics, and performing outcomes analysis. PACS components consist of acquisition nodes, archives, and output devices. Acquisition nodes may include "digital modalities" such as CT, MRI, nuclear medicine, and computed radiography (CR), along with devices to convert from analog to digital, such as digitizers and frame grabbers. Options for archives are discussed along with configuration schemes. Output devices include both hard copy (film and paper prints) and soft copy (workstations for display and diagnosis). Finally, a description of the PACS installations at the University of Florida is presented, with comments on some of the difficulties and complexities encountered. A discussion of the cost and benefits of PACS is included, along with a forecast of the future of

  13. Phonons with orbital angular momentum

    SciTech Connect

    Ayub, M. K.; Ali, S.; Mendonca, J. T.

    2011-10-15

    Ion accoustic waves or phonon modes are studied with orbital angular momentum (OAM) in an unmagnetized collissionless uniform plasma, whose constituents are the Boltzmann electrons and inertial ions. For this purpose, we have employed the fluid equations to obtain a paraxial equation in terms of ion density perturbations and discussed its Gaussian beam and Laguerre-Gauss (LG) beam solutions. Furthermore, an approximate solution for the electrostatic potential problem is presented, allowing to express the components of the electric field in terms of LG potential perturbations. The energy flux due to phonons is also calculated and the corresponding OAM is derived. Numerically, it is shown that the parameters such as azimuthal angle, radial and angular mode numbers, and beam waist, strongly modify the profiles of the phonon LG potential. The present results should be helpful in understanding the phonon mode excitations produced by Brillouin backscattering of laser beams in a uniform plasma.

  14. Inhomogeneous broadening of PAC spectra with V zz and η joint probability distribution functions

    NASA Astrophysics Data System (ADS)

    Evenson, W. E.; Adams, M.; Bunker, A.; Hodges, J.; Matheson, P.; Park, T.; Stufflebeam, M.; Zacate, M. O.

    2013-05-01

    The perturbed angular correlation (PAC) spectrum, G 2( t), is broadened by the presence of randomly distributed defects in crystals due to a distribution of electric field gradients (EFGs) experienced by probe nuclei. Heuristic approaches to fitting spectra that exhibit such inhomogeneous broadening (ihb) consider only the distribution of EFG magnitudes V zz , but the physical effect actually depends on the joint probability distribution function (pdf) of V zz and EFG asymmetry parameter η. The difficulty in determining the joint pdf leads us to more appropriate representations of the EFG coordinates, and to express the joint pdf as the product of two approximately independent pdfs describing each coordinate separately. We have pursued this case in detail using as an initial illustration of the method a simple point defect model with nuclear spin I = 5/2 in several cubic lattices, where G 2( t) is primarily induced by a defect trapped in the first neighbor shell of a probe and broadening is due to defects distributed at random outside the first neighbor shell. Effects such as lattice relaxation are ignored in this simple test of the method. The simplicity of our model is suitable for gaining insight into ihb with more than V zz alone. We simulate ihb in this simple case by averaging the net EFGs of 20,000 random defect arrangements, resulting in a broadened average G 2( t). The 20,000 random cases provide a distribution of EFG components which are first transformed to Czjzek coordinates and then further into the full Czjzek half plane by conformal mapping. The topology of this transformed space yields an approximately separable joint pdf for the EFG components. We then fit the nearly independent pdfs and reconstruct G 2( t) as a function of defect concentration. We report results for distributions of defects on simple cubic, face-centered cubic, and body-centered cubic lattices. The method explored here for analyzing ihb is applicable to more realistic cases.

  15. PacBio Sequencing and Its Applications

    PubMed Central

    Rhoads, Anthony; Au, Kin Fai

    2015-01-01

    Single-molecule, real-time sequencing developed by Pacific BioSciences offers longer read lengths than the second-generation sequencing (SGS) technologies, making it well-suited for unsolved problems in genome, transcriptome, and epigenetics research. The highly-contiguous de novo assemblies using PacBio sequencing can close gaps in current reference assemblies and characterize structural variation (SV) in personal genomes. With longer reads, we can sequence through extended repetitive regions and detect mutations, many of which are associated with diseases. Moreover, PacBio transcriptome sequencing is advantageous for the identification of gene isoforms and facilitates reliable discoveries of novel genes and novel isoforms of annotated genes, due to its ability to sequence full-length transcripts or fragments with significant lengths. Additionally, PacBio’s sequencing technique provides information that is useful for the direct detection of base modifications, such as methylation. In addition to using PacBio sequencing alone, many hybrid sequencing strategies have been developed to make use of more accurate short reads in conjunction with PacBio long reads. In general, hybrid sequencing strategies are more affordable and scalable especially for small-size laboratories than using PacBio Sequencing alone. The advent of PacBio sequencing has made available much information that could not be obtained via SGS alone. PMID:26542840

  16. 24 CFR 891.735 - Notice upon PAC expiration.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Notice upon PAC expiration. 891.735... and Individuals-Section 162 Assistance § 891.735 Notice upon PAC expiration. The PAC will provide that the Borrower will, at least 90 days before the end of the PAC contract term, notify each...

  17. 24 CFR 891.735 - Notice upon PAC expiration.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Notice upon PAC expiration. 891.735... and Individuals-Section 162 Assistance § 891.735 Notice upon PAC expiration. The PAC will provide that the Borrower will, at least 90 days before the end of the PAC contract term, notify each...

  18. Production of 62Zn radioactive nuclear beam and on-line PAC investigation of quadrupole interaction in nano-magnetic material Fe73.5Cu1Nb3Si13.5B9

    NASA Astrophysics Data System (ADS)

    Zuo, Yi; Zheng, Yongnan; Xu, Yongjun; Cui, Baoqun; Li, Liqiang; Ma, Yingjun; Ping, Fan; Yuan, Daqing; Gao, Shuang; Zhu, Shengyun

    2013-05-01

    An Isotope Separator On-Line (ISOL), dedicated to on-line perturbed angular correlation (PAC) and positron annihilation spectroscopy (PAS), has been constructed at CIAE based on the HI-13 tandem accelerator, and a 30 keV radioactive beam of 62Zn with intensity of 2 ×107/s produced by it. Using the 62Zn radioactive beam the investigation of the nano-crystalline soft magnetic Fe73.5Cu1Nb3Si13.5B9 materials has been fulfiled for the first time by the on-line time differential PAC technique. Two quadrupole interaction frequencies ω 01 ( = 440 Mrad/s) and ω 02 ( = 90 Mrad/s) were gained, indicating there are two implantation sites of 62Zn. The frequency ω 02 shows a fluctuation of the crystal lattice constants and proves the characteristic distribution model of nano-crystalline grain boundary. The frequency ω 01 demonstrates that the implanted 62Zn occupies the site of the ordered grain core. The fractions of ω 01 and ω 02 are f01 = 38 % and f02 = 62 %, respectively.

  19. Evaluation of a hospital-wide PACS: costs and benefits of the Hammersmith PACS installation

    NASA Astrophysics Data System (ADS)

    Bryan, Stirling; Keen, Justin; Buxton, Martin J.; Weatherburn, Gwyneth C.

    1992-07-01

    The unusual nature of sites chosen for hospital-wide PACS implementations and the very small number of proposed implementations make evaluation a complex task. The UK Department of Health is funding both the evaluation and implementation of a hospital-wide PACS. The Brunel University evaluation of the Hammersmith Hospital PACS has two main components: an economic evaluation of the costs and benefits of hospital-wide PACS installations and an exercise in monitoring the implementation process. This paper concentrates on the economic component.

  20. Pac-ing the Most into Genetics.

    ERIC Educational Resources Information Center

    Journet, Alan R. P.

    1984-01-01

    Describes the use of a Pac-Man model (called a Pactype) in teaching various genetics concepts. Indicates that students can learn to make predictions, analyze patterns of inheritance, and evaluate hypotheses before being introduced to the genetics vocabulary. (JN)

  1. Preparing a cultural strategy for PACS.

    PubMed

    Lawrence, Paul

    2005-01-01

    Health Central Hospital in Ocoee, FL, performs in excess of 100,000 studies per year. In September 2003, it was determined that a picture archiving and communication system (PACS)--already an agenda item set for the current fiscal year-would have a go-live date of no later than July 1, 2004. That meant 9 months to research, develop, and implement the project. The objective was to bring PACS to fruition quickly and smoothly, have buy-in from all parties concerned, and not interrupt the daily flow of patient care in the process. The first step in the project was to select the vendors to be considered. Working closely with the radiology leadership team, a list of physicians who most frequently requested film was compiled. Among them, the team targeted 3 or 4 that it was believed would help champion the effort with their fellow physicians. Along with these pieces, the radiologists, physicians on staff at the hospital, and, of course, the nursing and administrative teams would be an integral part of the project. The groundwork was laid for hiring a consultant to assist in the process. A PACS coordinator job description was created. Then, a staff meeting was called to discuss routine business issues and bring PACS to the table. It is extremely important to bring all relative new data to the staff throughout the project. After that initial meeting, PACS was a regular agenda item. A project team was comprised of 6 persons from radiology, information systems (IS), and administration, as well as a radiologist. Each member was required to make all 4 site visits, give a brief written evaluation of the product seen, and provide a brief narrative for and against the equipment. The vendor was selected, a final proposal was obtained, and contract details were negotiated. A PACS Steering Committee was appointed, and a PACS coordinator and consultant were hired. The PACS was installed, and a computed radiography (CR) system was purchased and integrated with the PACS. Training was

  2. Overview of Polycyclic Aromatic Compounds (PAC)

    PubMed Central

    Achten, Christine; Andersson, Jan T.

    2015-01-01

    The chemical group of polycyclic aromatic compounds (PAC), including the better-known subgroup of polycyclic aromatic hydrocarbons (PAH) and the heterocyclic aromatic compounds (NSO-PAC, heterocycles), comprise several thousand individual compounds. It is hard to find a comprehensive overview in the literature of these PACs that includes a substantial amount of relevant properties. Here an attempt is made to summarize the most studied but also some less well-known PACs. In addition to basic data such as recommended names, abbreviations, CAS numbers, molecular formulas, chemical structures, and exact mono-isotopic molecular weights, physico-chemical properties taken from the literature like boiling points, vapor pressures, water solubilities, Henry's Law constants, n-octanol-water partition coefficients (log KOW), and pKa are summarized. Selected toxicological data are listed indicating carcinogenic and mutagenic activity or effects on different organisms. PAC nomenclature is a complex topic, so suggestions for practical use are made. Regarding available data, estimated (instead of measured) values should be used with caution because considerable deviations from experimentally determined values can occur. For an enhanced understanding of the behavior of single PACs in comparison with each other, some of the properties mentioned above are plotted vs. the number of rings or the degree of alkylation. Also, some physico-chemical data are correlated with different functional groups as substituents of the PAHs. This article reveals that rather little is known about the less common PACs, e.g., higher molecular weight compounds, alkylated or otherwise substituted aromatics, for instance, keto-, oxo-, amino-, nitro-, cyano-PAHs, or some heterocyclic aromatic compounds, including their derivatives. It mirrors the limited state of knowledge about the variety of PACs that do not belong to the 16 EPA PAHs. PMID:26823644

  3. Impact of PACS in hospital management

    NASA Astrophysics Data System (ADS)

    Hur, Gham; Cha, Soon-Joo; Kim, Yong H.; Hwang, Yoon J.; Kim, Soo Y.

    2002-05-01

    Since the low-cost, NT-based, full PACS was successfully implemented in a large-scale hospital at the end of 1999, many hospital administrators have rushed to purchase the system competitively. It is now a worldwide trend to implement the technology, but Korea has several unique environments for the fast spread of the full PACS. Since hospitals in Korea operate inpatient and outpatient clinics in the same building and use identical OCS, full integration of PACS with the OCS was relatively easy and highly efficient. The simple governing structures of the hospitals also made the decision-making process short and effective. In addition, the national health insurance reimbursement policy that started pay in the beginning of 2000 has also played a catalytic role for the swift propagation of PACS. The recent appearance of the affordable PACS gave hospital administrators the opportunity to learn and understand the role of digital imaging in the areas that are directly related to the efficiency and quality of medical services, as well as cost containment. Furthermore, PACS provided them with windows to the 'all-digital hospital,' which will lead them to realign policies in the management of the hospitals in order to compete successfully in the fast-changing world of health care.

  4. High strength distillery wastewater treatment by a PAC-MBR with low PAC dosage.

    PubMed

    Basu, Subhankar; Kaushik, Ankita; Saranya, P; Batra, Vidya S; Balakrishnan, Malini

    2016-01-01

    Augmentation of membrane bioreactors (MBRs) with activated carbon is established to offer several operational advantages. This work investigates the influence of low dosing (2 g/L) of powdered activated carbons (PACs) with different characteristics on the performance of MBR treating high strength molasses distillery wastewater containing difficult-to-biodegrade recalcitrant components. Two MBRs, augmented with different PACs, were operated in parallel over a period of 240 days and their performance monitored in terms of biomass growth, reduction in chemical oxygen demand (COD), sludge properties like extracellular polymeric substances content, filterability, and morphology. Removal of organics and coloring matter by adsorption, biodegradation and membrane filtration was estimated. Although adsorptive removal of color and COD is influenced by the properties of the PAC used, the performance of the PAC-MBRs was independent of PAC properties. Both PACs preferentially adsorbed the low molecular weight components in distillery wastewater. Retention by the membrane filter with the secondary cake layer contributed to reduction in color and COD of treated effluent. The findings indicate that low dosing with PAC adsorbing low molecular weight organics has a limited role in PAC-MBR treating distillery wastewater. PMID:26942533

  5. High strength distillery wastewater treatment by a PAC-MBR with low PAC dosage.

    PubMed

    Basu, Subhankar; Kaushik, Ankita; Saranya, P; Batra, Vidya S; Balakrishnan, Malini

    2016-01-01

    Augmentation of membrane bioreactors (MBRs) with activated carbon is established to offer several operational advantages. This work investigates the influence of low dosing (2 g/L) of powdered activated carbons (PACs) with different characteristics on the performance of MBR treating high strength molasses distillery wastewater containing difficult-to-biodegrade recalcitrant components. Two MBRs, augmented with different PACs, were operated in parallel over a period of 240 days and their performance monitored in terms of biomass growth, reduction in chemical oxygen demand (COD), sludge properties like extracellular polymeric substances content, filterability, and morphology. Removal of organics and coloring matter by adsorption, biodegradation and membrane filtration was estimated. Although adsorptive removal of color and COD is influenced by the properties of the PAC used, the performance of the PAC-MBRs was independent of PAC properties. Both PACs preferentially adsorbed the low molecular weight components in distillery wastewater. Retention by the membrane filter with the secondary cake layer contributed to reduction in color and COD of treated effluent. The findings indicate that low dosing with PAC adsorbing low molecular weight organics has a limited role in PAC-MBR treating distillery wastewater.

  6. The angular momentum of the Oort cloud

    NASA Technical Reports Server (NTRS)

    Weissman, Paul R.

    1991-01-01

    An evaluation is made of the work of Marochnik et al. (1988), which estimated that the angular momentum of the Oort cloud is 2-3 orders of magnitude greater than the planetary system's total angular momentum. It is noted that most of the angular momentum in the currently observed Oort cloud is the result of the effects of external perturbers over the solar system's history, and it is demonstrated that the total current angular momentum is probably in the 6.0 x 10 to the 50th to 1.1 x 10 to the 51st g sq cm/sec range; original angular momentum was probably a factor of 5 below such values.

  7. The angular momentum of the Oort cloud

    SciTech Connect

    Weissman, P.R. )

    1991-01-01

    An evaluation is made of the work of Marochnik et al. (1988), which estimated that the angular momentum of the Oort cloud is 2-3 orders of magnitude greater than the planetary system's total angular momentum. It is noted that most of the angular momentum in the currently observed Oort cloud is the result of the effects of external perturbers over the solar system's history, and it is demonstrated that the total current angular momentum is probably in the 6.0 x 10 to the 50th to 1.1 x 10 to the 51st g sq cm/sec range; original angular momentum was probably a factor of 5 below such values. 21 refs.

  8. Experience with high-performance PACS

    NASA Astrophysics Data System (ADS)

    Wilson, Dennis L.; Goldburgh, Mitchell M.; Head, Calvin

    1997-05-01

    Lockheed Martin (Loral) has installed PACS with associated teleradiology in several tens of hospitals. The PACS that have been installed have been the basis for a shift to filmless radiology in many of the hospitals. the basic structure for the PACS and the teleradiology that is being used is outlined. The way that the PACS are being used in the hospitals is instructive. The three most used areas for radiology in the hospital are the wards including the ICU wards, the emergency room, and the orthopedics clinic. The examinations are mostly CR images with 20 percent to 30 percent of the examinations being CT, MR, and ultrasound exams. The PACS are being used to realize improved productivity for radiology and for the clinicians. For radiology the same staff is being used for 30 to 50 percent more workload. For the clinicians 10 to 20 percent of their time is being saved in dealing with radiology images. The improved productivity stems from the high performance of the PACS that has been designed and installed. Images are available on any workstation in the hospital within less than two seconds, even during the busiest hour of the day. The examination management functions to restrict the attention of any one user to the examinations that are of interest. The examination management organizes the workflow through the radiology department and the hospital, improving the service of the radiology department by reducing the time until the information from a radiology examination is available. The remaining weak link in the PACS system is transcription. The examination can be acquired, read, an the report dictated in much less than ten minutes. The transcription of the dictated reports can take from a few hours to a few days. The addition of automatic transcription services will remove this weak link.

  9. Design of PACs for high-performance photoresists (I): role of di-esterified PACs having hindered -OH groups

    NASA Astrophysics Data System (ADS)

    Hanawa, Ryotaro; Uetani, Yasunori; Hanabata, Makoto

    1992-06-01

    Steric hindrance on a ballast molecule causes selective esterification of -OH groups and provides novel di-esterified PACs having -OH group(s) with high selectivity. These novel PACs give photoresists higher sensitivities, (gamma) -values and resolutions, than those of fully esterified PACs. Also, these novel PACs provide scum-free patterns. Comparison of dissolution properties of a novel di-esterified PAC having a sterically hindered -OH with those of a di-esterified PAC suggests that the presence of -OH enhances dissolution rates, but it does not change the slope of logR-logE plots. DRM's agitated development reduces a large (gamma) -value of a novel PAC observed in puddle development. On the other hand, (gamma) -values of fully esterified PACs were not affected by the change of development methods. This observation suggests significance of (gamma) - value evaluation by puddle development for the investigation of high performance PACs.

  10. From PACS to integrated EMR.

    PubMed

    Ratib, Osman; Swiernik, Michael; McCoy, J Michael

    2003-01-01

    The integration of medical images as part of the patient record has always been a critical component of documentation and information supporting clinical decisions. In the past two decades the increased number of imaging procedures that allows a more accurate and more specific diagnosis has significantly increased and their role in patient management has grown rapidly. With the evolution toward digital modalities and management of medical images in a fully digital environment with the deployment of enterprise wide Picture Archiving Communication Systems (PACS) a wider and more rapid access to the images by referring physicians and clinicians has become possible. The parallel evolution of electronic medical records (EMR) supporting all other documents and clinical data in electronic format led to the necessity of integrating medial image data with the rest of the patient record. Although the marriage of medical images and patient record data in electronic format seems a very natural and necessary combination it has often been very slow in development due to the lack of standardization and clear understanding of clinical workflows and clinical requirements. Several early implementations demonstrated the added value of combining medical images with the patient record and have shown that the availability of data and images facilitates and improves the accuracy and efficiency of patient management. Recent efforts in industry and the academic community to harmonize and improve the integration of medical images with patient record, with the promotion of new standards and better definitions of clinical workflows and standard mechanism of integration of different types of data into unified data models, has facilitated the deployment of modern EMR. Also, a shift in paradigm due to recent technological revolutions such as the development of the World Wide Web and the concepts of portal servers for accessing data for multiple sources has significantly boosted the trends into

  11. A Layered Approach To Pacs Network Architecture

    NASA Astrophysics Data System (ADS)

    Hegde, Shankar S.; Prewitt, Judith M.

    1984-08-01

    Although the functions performed by the different nodes on the PACS network are many, it is possible to formulate a minimum set of service primitives such that the application software residing at the nodes can utilize those primitives to perform the functions. These primitives define the framework for the communication interface. The question of how these primitives fit into the concept of a layered network architecture is explored in this paper. The OSI model as applicable to the PACS network is described, the areas that need standardization are briefly mentioned, and the ongoing standardization efforts are addressed from the OSI perspective.

  12. Future trends in Picture Archiving and Communication System (PACS).

    PubMed

    Al-Hajeri, Mona; Clarke, Malcom

    2015-01-01

    This research investigates the opinions of radiologists regards requirements for improving current Picture Archiving and Communication System (PACS). Responses to a questionnaire were collected from 120 of the 200 radiologists in five governmental hospitals of Kuwait. The study the determines the importance of the solutions for future PACS from the radiologists point of view as: PACS must be integrated with other hospital information systems (100%); there must be multi hospital PACS access across different organizations (99%); web based PACS solutions (97%) and PACS applications in mobile phones (97%) are seen as an improved solution for future PACS. Whereas, the radiologists expressed strong concerns over the barriers for implementing web PACS solutions including: technical issues (91%); lack of training (85%); and cost (76%). PMID:26737865

  13. 24 CFR 891.710 - Term of PAC.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Term of PAC. 891.710 Section 891... Individuals-Section 162 Assistance § 891.710 Term of PAC. The term of the PAC shall be 20 years. If the project is completed in stages, the term of the PAC for each stage shall be 20 years. The term of the...

  14. 24 CFR 891.710 - Term of PAC.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Term of PAC. 891.710 Section 891... Individuals-Section 162 Assistance § 891.710 Term of PAC. The term of the PAC shall be 20 years. If the project is completed in stages, the term of the PAC for each stage shall be 20 years. The term of the...

  15. Acceptance testing for PACS: from methodology to design to implementation

    NASA Astrophysics Data System (ADS)

    Liu, Brent J.; Huang, H. K.

    2004-04-01

    Acceptance Testing (AT) is a crucial step in the implementation process of a PACS within a clinical environment. AT determines whether the PACS is ready for clinical use and marks the official sign off of the PACS product. Most PACS vendors have Acceptance Testing (AT) plans, however, these plans do not provide a complete and robust evaluation of the full system. In addition, different sites will have different special requirements that vendor AT plans do not cover. The purpose of this paper is to introduce a protocol for AT design and present case studies of AT performed on clinical PACS. A methodology is presented that includes identifying testing components within PACS, quality assurance for both functionality and performance, and technical testing focusing on key single points-of-failure within the PACS product. Tools and resources that provide assistance in performing AT are discussed. In addition, implementation of the AT within the clinical environment and the overall implementation timeline of the PACS process are presented. Finally, case studies of actual AT of clinical PACS performed in the healthcare environment will be reviewed. The methodology for designing and implementing a robust AT plan for PACS was documented and has been used in PACS acceptance tests in several sites. This methodology can be applied to any PACS and can be used as a validation for the PACS product being acquired by radiology departments and hospitals. A methodology for AT design and implementation was presented that can be applied to future PACS installations. A robust AT plan for a PACS installation can increase both the utilization and satisfaction of a successful implementation of a PACS product that benefits both vendor and customer.

  16. Power Pacs for Teaching Home Economics Related Science and Math.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Education, Columbus. Div. of Vocational Education.

    This guide contains materials designed to assist teachers and students in home economics related courses with mastery of job-related mathematics, science, and behavioral science. The 40 Power Pacs are divided into mathematics (16 Power Pacs), science (15), and behavioral science (9). Each Power Pac contains teacher materials and student materials.…

  17. Update on digital image management and PACS.

    PubMed

    Ratib, O; Ligier, Y; Bandon, D; Valentino, D

    2000-01-01

    Information technology is becoming a vital component of all health care enterprises, from managed care services to large hospital networks, that provides the basis of electronic patient records and hospital-wide information. The rationale behind such systems is deceptively simple: physicians want to sit down at a single workstation and call up all information, both clinical data and medical images, concerning a given patient. Picture archiving and communication systems (PACS) are responsible for solving the problem of acquiring, transmitting, and displaying radiologic images. The major benefit of PACS resides in its ability to communicate images and reports to referring physicians in a timely and reliable fashion. With the changes in economics and the shift toward managed and capitated care, the teleradiology component of PACS is rapidly gaining momentum. In allowing remote coverage of multiple sites by the same radiologists and remote consultations and expert opinion, teleradiology is in many instances the only option to maintain economically viable radiologic settings. The technical evolution toward more integrated systems and the shift toward Web-based technology is rapidly merging the two concepts of PACS and teleradiology in global image management and communication systems.

  18. Anatomy of an Extensible Open Source PACS.

    PubMed

    Valente, Frederico; Silva, Luís A Bastião; Godinho, Tiago Marques; Costa, Carlos

    2016-06-01

    The conception and deployment of cost effective Picture Archiving and Communication Systems (PACS) is a concern for small to medium medical imaging facilities, research environments, and developing countries' healthcare institutions. Financial constraints and the specificity of these scenarios contribute to a low adoption rate of PACS in those environments. Furthermore, with the advent of ubiquitous computing and new initiatives to improve healthcare information technologies and data sharing, such as IHE and XDS-i, a PACS must adapt quickly to changes. This paper describes Dicoogle, a software framework that enables developers and researchers to quickly prototype and deploy new functionality taking advantage of the embedded Digital Imaging and Communications in Medicine (DICOM) services. This full-fledged implementation of a PACS archive is very amenable to extension due to its plugin-based architecture and out-of-the-box functionality, which enables the exploration of large DICOM datasets and associated metadata. These characteristics make the proposed solution very interesting for prototyping, experimentation, and bridging functionality with deployed applications. Besides being an advanced mechanism for data discovery and retrieval based on DICOM object indexing, it enables the detection of inconsistencies in an institution's data and processes. Several use cases have benefited from this approach such as radiation dosage monitoring, Content-Based Image Retrieval (CBIR), and the use of the framework as support for classes targeting software engineering for clinical contexts. PMID:26497879

  19. Anatomy of an Extensible Open Source PACS.

    PubMed

    Valente, Frederico; Silva, Luís A Bastião; Godinho, Tiago Marques; Costa, Carlos

    2016-06-01

    The conception and deployment of cost effective Picture Archiving and Communication Systems (PACS) is a concern for small to medium medical imaging facilities, research environments, and developing countries' healthcare institutions. Financial constraints and the specificity of these scenarios contribute to a low adoption rate of PACS in those environments. Furthermore, with the advent of ubiquitous computing and new initiatives to improve healthcare information technologies and data sharing, such as IHE and XDS-i, a PACS must adapt quickly to changes. This paper describes Dicoogle, a software framework that enables developers and researchers to quickly prototype and deploy new functionality taking advantage of the embedded Digital Imaging and Communications in Medicine (DICOM) services. This full-fledged implementation of a PACS archive is very amenable to extension due to its plugin-based architecture and out-of-the-box functionality, which enables the exploration of large DICOM datasets and associated metadata. These characteristics make the proposed solution very interesting for prototyping, experimentation, and bridging functionality with deployed applications. Besides being an advanced mechanism for data discovery and retrieval based on DICOM object indexing, it enables the detection of inconsistencies in an institution's data and processes. Several use cases have benefited from this approach such as radiation dosage monitoring, Content-Based Image Retrieval (CBIR), and the use of the framework as support for classes targeting software engineering for clinical contexts.

  20. COMPENDEX/TEXT-PAC: RETROSPECTIVE SEARCH.

    ERIC Educational Resources Information Center

    Standera, Oldrich

    The Text-Pac System is capable of generating indexes and bulletins to provide a current information service without the selectivity feature. Indexes of the accumulated data base may also be used as a basis for manual retrospective searching. The manual search involves searching computer-prepared indexes from a machine readable data base produced…

  1. Medical imaging, PACS, and imaging informatics: retrospective.

    PubMed

    Huang, H K

    2014-01-01

    Historical reviews of PACS (picture archiving and communication system) and imaging informatics development from different points of view have been published in the past (Huang in Euro J Radiol 78:163-176, 2011; Lemke in Euro J Radiol 78:177-183, 2011; Inamura and Jong in Euro J Radiol 78:184-189, 2011). This retrospective attempts to look at the topic from a different angle by identifying certain basic medical imaging inventions in the 1960s and 1970s which had conceptually defined basic components of PACS guiding its course of development in the 1980s and 1990s, as well as subsequent imaging informatics research in the 2000s. In medical imaging, the emphasis was on the innovations at Georgetown University in Washington, DC, in the 1960s and 1970s. During the 1980s and 1990s, research and training support from US government agencies and public and private medical imaging manufacturers became available for training of young talents in biomedical physics and for developing the key components required for PACS development. In the 2000s, computer hardware and software as well as communication networks advanced by leaps and bounds, opening the door for medical imaging informatics to flourish. Because many key components required for the PACS operation were developed by the UCLA PACS Team and its collaborative partners in the 1980s, this presentation is centered on that aspect. During this period, substantial collaborative research efforts by many individual teams in the US and in Japan were highlighted. Credits are due particularly to the Pattern Recognition Laboratory at Georgetown University, and the computed radiography (CR) development at the Fuji Electric Corp. in collaboration with Stanford University in the 1970s; the Image Processing Laboratory at UCLA in the 1980s-1990s; as well as the early PACS development at the Hokkaido University, Sapporo, Japan, in the late 1970s, and film scanner and digital radiography developed by Konishiroku Photo Ind. Co. Ltd

  2. Medical imaging, PACS, and imaging informatics: retrospective.

    PubMed

    Huang, H K

    2014-01-01

    Historical reviews of PACS (picture archiving and communication system) and imaging informatics development from different points of view have been published in the past (Huang in Euro J Radiol 78:163-176, 2011; Lemke in Euro J Radiol 78:177-183, 2011; Inamura and Jong in Euro J Radiol 78:184-189, 2011). This retrospective attempts to look at the topic from a different angle by identifying certain basic medical imaging inventions in the 1960s and 1970s which had conceptually defined basic components of PACS guiding its course of development in the 1980s and 1990s, as well as subsequent imaging informatics research in the 2000s. In medical imaging, the emphasis was on the innovations at Georgetown University in Washington, DC, in the 1960s and 1970s. During the 1980s and 1990s, research and training support from US government agencies and public and private medical imaging manufacturers became available for training of young talents in biomedical physics and for developing the key components required for PACS development. In the 2000s, computer hardware and software as well as communication networks advanced by leaps and bounds, opening the door for medical imaging informatics to flourish. Because many key components required for the PACS operation were developed by the UCLA PACS Team and its collaborative partners in the 1980s, this presentation is centered on that aspect. During this period, substantial collaborative research efforts by many individual teams in the US and in Japan were highlighted. Credits are due particularly to the Pattern Recognition Laboratory at Georgetown University, and the computed radiography (CR) development at the Fuji Electric Corp. in collaboration with Stanford University in the 1970s; the Image Processing Laboratory at UCLA in the 1980s-1990s; as well as the early PACS development at the Hokkaido University, Sapporo, Japan, in the late 1970s, and film scanner and digital radiography developed by Konishiroku Photo Ind. Co. Ltd

  3. Future trends in picture archiving and communication system (PACS)

    NASA Astrophysics Data System (ADS)

    Al-Hajeri, Mona; Clarke, Malcolm

    2015-03-01

    Objective: This research investigates the needs and opinions of radiologists on the use of enhanced information technologies and approaches to improve the functionality of Picture Archiving and Communication Systems (PACS). Method: Six interviews were conducted in the main governmental hospital in Kuwait (AL-Sabah Hospital) with radiologists, including two senior radiologists, two junior radiologists, and two trainee radiologists undertaking the Irish radiology board. Results: The radiologists identified a number of limitations that exist in current PACS and requirements to enhance usability and functionality. However, it was the case that some of the radiologists had little knowledge about the advanced trends in PACS. Four themes emerged from the thematic analysis of the data: (1) limitations of traditional PACS; (2) Features and requirements that can increase PACS functionality; (3) web based solutions of PACS; (4) PACS in mobile phones. Conclusion: It is widely recognized that PACS has limitations. This research has identified themes that, when incorporated, will enhance the functionality of PACS and provide better quality clinical practice. This research has determined the important future trends of PACS. Primarily web based solutions and use in mobile phones. The findings from this research can be used as recommendations to vendors, for product development and medical institutes to consider when undertaking implementation of PACS and training future radiologists.

  4. The importance of a picture archiving and communications system (PACS) manager for large-scale PACS installations.

    PubMed

    Beird, L C

    1999-05-01

    Installing a picture archiving and communication system (PACS) is a massive undertaking for any radiology department. Facilities making a successful transition to digital systems are finding that a PACS manager helps guide the way and offers a heightened return on the investment. The PACS manager fills a pivotal role in a multiyear, phased PACS installation. PACS managers navigate a facility through the complex sea of issues surrounding a PACS installation by coordinating the efforts of the vendor, radiology staff, hospital administration, and the information technology group. They are involved in the process from the purchase decision through the design and implementation phases. They can help administrators justify a PACS, purchase and shape the request for proposal (RFP) process before a vendor is even chosen. Once a supplier has been selected, the PACS manager works closely with the vendor and facility staff to determine the best equipment configuration for his or her facility, and makes certain that all deadlines are met during the planning and installation phase. The PACS manager also ensures that the infrastructure and backbone of the facility are ready for installation of the equipment. PACS managers also help the radiology staff gain acceptance of the technology by serving as teachers, troubleshooters, and the primary point-of-contact for all PACS issues. This session will demonstrate the value of a PACS manager, as well as point out ways to determine the manager's responsibilities. By the end of the session, participants will be able to describe the role of a PACS manager as it relates to departmental operation and in partnership with equipment vendors, justify a full-time position for a PACS manager, and identify the qualifications of candidates for the position of PACS manager.

  5. PACS administrators' and radiologists' perspective on the importance of features for PACS selection.

    PubMed

    Joshi, Vivek; Narra, Vamsi R; Joshi, Kailash; Lee, Kyootai; Melson, David

    2014-08-01

    Picture archiving and communication systems (PACS) play a critical role in radiology. This paper presents the criteria important to PACS administrators for selecting a PACS. A set of criteria are identified and organized into an integrative hierarchical framework. Survey responses from 48 administrators are used to identify the relative weights of these criteria through an analytical hierarchy process. The five main dimensions for PACS selection in order of importance are system continuity and functionality, system performance and architecture, user interface for workflow management, user interface for image manipulation, and display quality. Among the subdimensions, the highest weights were assessed for security, backup, and continuity; tools for continuous performance monitoring; support for multispecialty images; and voice recognition/transcription. PACS administrators' preferences were generally in line with that of previously reported results for radiologists. Both groups assigned the highest priority to ensuring business continuity and preventing loss of data through features such as security, backup, downtime prevention, and tools for continuous PACS performance monitoring. PACS administrators' next high priorities were support for multispecialty images, image retrieval speeds from short-term and long-term storage, real-time monitoring, and architectural issues of compatibility and integration with other products. Thus, next to ensuring business continuity, administrators' focus was on issues that impact their ability to deliver services and support. On the other hand, radiologists gave high priorities to voice recognition, transcription, and reporting; structured reporting; and convenience and responsiveness in manipulation of images. Thus, radiologists' focus appears to be on issues that may impact their productivity, effort, and accuracy. PMID:24744278

  6. PACS administrators' and radiologists' perspective on the importance of features for PACS selection.

    PubMed

    Joshi, Vivek; Narra, Vamsi R; Joshi, Kailash; Lee, Kyootai; Melson, David

    2014-08-01

    Picture archiving and communication systems (PACS) play a critical role in radiology. This paper presents the criteria important to PACS administrators for selecting a PACS. A set of criteria are identified and organized into an integrative hierarchical framework. Survey responses from 48 administrators are used to identify the relative weights of these criteria through an analytical hierarchy process. The five main dimensions for PACS selection in order of importance are system continuity and functionality, system performance and architecture, user interface for workflow management, user interface for image manipulation, and display quality. Among the subdimensions, the highest weights were assessed for security, backup, and continuity; tools for continuous performance monitoring; support for multispecialty images; and voice recognition/transcription. PACS administrators' preferences were generally in line with that of previously reported results for radiologists. Both groups assigned the highest priority to ensuring business continuity and preventing loss of data through features such as security, backup, downtime prevention, and tools for continuous PACS performance monitoring. PACS administrators' next high priorities were support for multispecialty images, image retrieval speeds from short-term and long-term storage, real-time monitoring, and architectural issues of compatibility and integration with other products. Thus, next to ensuring business continuity, administrators' focus was on issues that impact their ability to deliver services and support. On the other hand, radiologists gave high priorities to voice recognition, transcription, and reporting; structured reporting; and convenience and responsiveness in manipulation of images. Thus, radiologists' focus appears to be on issues that may impact their productivity, effort, and accuracy.

  7. Gyroscope test of gravitation: An analysis of the important perturbations

    NASA Technical Reports Server (NTRS)

    Oconnell, R. F.

    1971-01-01

    Two perturbations, the earth's quadrupole moment and the earth's revolution around the sun, are discussed. Schiff's proposed gyroscope test of gravitation is analyzed, along with the capability of deciphering each separate contribution to the angular velocity of spin precession.

  8. Authenticity techniques for PACS images and records

    NASA Astrophysics Data System (ADS)

    Wong, Stephen T. C.; Abundo, Marco; Huang, H. K.

    1995-05-01

    Along with the digital radiology environment supported by picture archiving and communication systems (PACS) comes a new problem: How to establish trust in multimedia medical data that exist only in the easily altered memory of a computer. Trust is characterized in terms of integrity and privacy of digital data. Two major self-enforcing techniques can be used to assure the authenticity of electronic images and text -- key-based cryptography and digital time stamping. Key-based cryptography associates the content of an image with the originator using one or two distinct keys and prevents alteration of the document by anyone other than the originator. A digital time stamping algorithm generates a characteristic `digital fingerprint' for the original document using a mathematical hash function, and checks that it has not been modified. This paper discusses these cryptographic algorithms and their appropriateness for a PACS environment. It also presents experimental results of cryptographic algorithms on several imaging modalities.

  9. Pacs: Part Of An Integrated Communications System

    NASA Astrophysics Data System (ADS)

    Thompson, B. G.; Brenton, Bradley C.; Staab, Edward V.; Perry, J. Randolph; Parrish, Denise; Johnston, R. Eugene; Creasy, Jeffrey L.

    1985-09-01

    The Department of Radiology at the University of North Carolina-Chapel Hill (UNC) has developed the concept for an integrated picture archiving and communications system. A communications network has been installed, and computer facilities are being interfaced within radiology areas. Other projects include the establishment of a computer simulation model of departmental operations and assembly of a limited picture archival and communication system (PACS) beginning with the CT and NMR Modalities. While this approach may provide immediate clinical benefits, the initial thrust has been towards evaluation of prototype systems with flexibility for modifications. PACS operational parameters are being studied for their acceptability in support of radiology clinical services. The goal is to provide objective operational data as a basis for planning system improvements.

  10. Evaluation of PACS in a multihospital environment

    NASA Astrophysics Data System (ADS)

    Siegel, Eliot L.; Reiner, Bruce I.; Protopapas, Zenon

    1998-07-01

    Although a number of authors have described the challenges and benefits of filmless operation using a hospital-wide Picture Archival and Communication System (PACS), there have been few descriptions of a multi-hospital wide area PACS. The purpose of this paper is to describe our two and a half year experience with PACS in an integrated multi-facility health care environment, the Veterans Affairs Maryland Health Care System (VAMHCS). On June 17, 1995 the Radiology and Nuclear Medicine services became integrated for four medical centers forming the VA Maryland Health Care System creating a single multi-facility imaging department. The facilities consisted of the Baltimore VA (acute and outpatient care, tertiary referral center), Ft. Howard (primarily long term care), Perry Point (primarily psychiatric care), and the Baltimore Rehabilitation and extended care facility (nursing home). The combined number of studies at all four sites is slightly more than 80,000 examinations per year. In addition to residents and fellows, the number of radiologists at Baltimore was approximately seven, with two at Perry Point, one at Ft. Howard, and no radiologists at the Rehabilitation and Extended Care facility. A single HIS/RIS, which is located physically at the Baltimore VAMC is utilized for all four medical centers. The multi- facility image management and communication system utilizes two separate PAC Systems that are physically located at the Baltimore VA Medical Center (BVAMC). The commercial system (GE Medical Systems) has been in place in Baltimore for more than 41/2 years and is utilized primarily in the acquisition, storage, distribution and display of radiology and nuclear medicine studies. The second PACS is the VISTA Imaging System, which has been developed as a module of the VA's HIS/RIS by and for the Department of Veterans Affairs. All of the radiology images obtained on the commercial PACS are requested by the VISTA Imaging System using DICOM query/retrieve commands

  11. Impact Of Manual And Computer-Assisted PACS For Automated PACS

    NASA Astrophysics Data System (ADS)

    Lehr, James L.

    1983-05-01

    Considerations of totally electronic picture archiving system (PACS) often neglect the fact that every radiology practice currently has some system for storing and retrieving images and related alphanumeric data. Although these systems are usually manual, many departments now use on-line computers to help manage film flow. In either event, the creation of electronic PACS can be viewed as a classic data processing problem of automating an existing system, and the conversion should proceed through the usual steps of documenting the existing system in detail, and conducting feasibility studies and cost-benefit analyses. Documenting current systems should be facilitated by computer-assisted PACS - particularly documenting transaction volumes which can be provided as a by-product of radiology information management systems. Similarly cost-benefit analysis should be facilitated, although the cost/benefit ratio may be less favorable when comparing automated to computer-assisted PACS. Finally, information management features such as those provided by current on-line radiology systems provide a framework necessary to realize the full benefits of automated PACS.

  12. Data protection and security issues of PACS

    NASA Astrophysics Data System (ADS)

    Bakker, Albert R.

    1992-07-01

    It is observed that the dataprotection aspects of PACS have hardly been explored, while for Hospital Information Systems (HIS) considerable attention has been paid to these aspects. In the dataprotection domain around HIS we distinguish the aspects data integrity (safety), usage integrity (confidentiality, privacy) and availability. A wide range of measures (dealing with hardware, software or organization/procedures) has been suggested to achieve adequate protection. For each system a selection of the suggested measures has to be made, where risk is balanced against costs. It seems that it is taken for granted that the usual measures as implemented for HIS will also be adequate for PACS. In this paper dataprotection aspects for PACS are discussed. Apart from similarities with the HIS situation also differences will be identified. In particular safeguarding the image databank requires special measured. Dataprotection should not be an add-on of the system, it should be taken into account in the design phase. As an illustration two alternatives for the organization of the image databank will be considered from the point of view of dataprotection. The one being consecutive historical storage of images, the other the clustering of images of the same patient on the same volume in the storage system.

  13. Deep Herschel PACS point spread functions

    NASA Astrophysics Data System (ADS)

    Bocchio, M.; Bianchi, S.; Abergel, A.

    2016-06-01

    The knowledge of the point spread function (PSF) of imaging instruments represents a fundamental requirement for astronomical observations. The Herschel PACS PSFs delivered by the instrument control centre are obtained from observations of the Vesta asteroid, which provides a characterisation of the central part and, therefore, excludes fainter features. In many cases, however, information on both the core and wings of the PSFs is needed. With this aim, we combine Vesta and Mars dedicated observations and obtain PACS PSFs with an unprecedented dynamic range (~106) at slow and fast scan speeds for the three photometric bands. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.FITS files of our PACS PSFs (Fig. 2) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A117

  14. Design of a PACS cluster controller

    NASA Astrophysics Data System (ADS)

    Taira, Ricky K.; Wong, Albert W. K.; Stewart, Brent K.; Huang, H. K.

    1992-07-01

    Our PACS design consists of clusters of computerized devices. At the center of each cluster is an intelligent machine termed a cluster controller. A cluster controller performs the following tasks: (1) receives images from capture computers, (2) extracts descriptive text information describing the received studies, (3) updates a network-accessible database management system, (4) determines the destination workstations to forward the newly generated studies, (5) automatically retrieves necessary comparison images from a distributed optical archive, (6) automatically corrects the orientation of computed radiography images, (7) archives new studies onto optical disk, (8) deletes images stored on remote capture computers upon successful image archival, and (9) services archive retrieval requests from remote workstations and other cluster controllers. The cluster controller is the only class of PACS computers that must communicate with all other types of PACS nodes (acquisition, other cluster controllers, radiologist''s workstation, referring physician''s workstation, printing stations, and database servers). This paper presents details of the logical partitioning of computers into clusters and the central role of the cluster controller machines in image acquisition, image routing, optical archive management, and system reliability.

  15. Secure vendor environment (SVE) for PACS

    NASA Astrophysics Data System (ADS)

    Honeyman-Buck, Janice; Frost, Meryll

    2005-04-01

    A Secure Vendor Environment (SVE) was created to protect radiology modalities from network intrusion, worms, viruses, and other forms of damaging attacks. Many vendors do not attempt any form of network security and if an institution demands a non-standard and secure installation, a future system upgrade could and frequently does eliminate any security measures installed during the initial installation. The SVE isolates the vendor equipment behind a virtual firewall on a private network that is invisible to the outside world. All interactions must go though a device containing two network interface cards called an Application Processor that acts as a store-and forward router, performs DICOM repair, proxies modality worklist, and isolates the vendor modalities. A small VPN appliance can open the device temporarily for remote access by vendor engineers. Prior to the routine installation of the SVE, vendor equipment was often attacked by hostile network intruders and viruses or worms, sometimes rendering the equipment unusable until the vendor could reload the system. The resulted in considerable clinical downtime and loss of revenue. Since the relatively low cost SVE solution has routinely been installed with all new equipment, no intrusions have occurred, although our network sniffers and intrusion detectors indicate that we are constantly being scanned for vulnerability. Purpose: To provide a secure network for vendor equipment in a PACS environment while allowing vendor access for upgrades and system repairs. Method: The network administrators at our university believe that network security should be implemented at the machine level rather than relying on a firewall. A firewall solution could conceivably block unwanted intrusion from outside the university network, but would still allow literally thousands of potential network users to get through to the PACS network. All the PACS archive, display and routing systems are individually protected from intrusion, but

  16. Phenomenological Determination of the Orbital Angular Momentum

    SciTech Connect

    Ramsey, Gordon P.

    2009-08-04

    Measurements involving the gluon spin, {delta}G(x, t) and the corresponding asymmetry, A(x,t) = {delta}G(x,t)/G(x,t) play an important role in quantitative understanding of proton structure. We have modeled the asymmetry perturbatively and calculated model corrections to obtain information about non-perturbative spin-orbit effects. These models are consistent with existing COMPASS and HERMES data on the gluon asymmetry. The J{sub z} = (1/2) sum rule is used to generate values of orbital angular momentum at LO and NLO. For models consistent with data, the orbital angular momentum is small. Our studies specify accuracy that future measurements should achieve to constrain theoretical models for nucleon structure.

  17. Benzene removal by PAC in jet flocculation system

    SciTech Connect

    Sobrinho, J.A.H.; Thiem, L.T.; Alkhatib, E.A.

    1997-10-01

    A jet flocculator/powdered activated carbon (PAC) adsorption pilot plant was designed, built, and operated in order to evaluate a water treatment process capable of simultaneous adsorption of benzene and flocculation of PAC and silica clay particles. The jet flocculation/PAC system successfully combined, in the same reactor, flocculation of suspended solids by using jet mixing, solids retention using pall rings, and benzene removal by PAC adsorption. The advantages of this process included operational simplicity, reliability, and low energy consumption. The jet flocculator/PAC adsorption system was able to achieve suspended solids and benzene removals of approximately 80 and 95%, respectively, from an influent containing 70 mg/L of suspended solids (silica clay and PAC) and 100 {micro}g/L of benzene.

  18. On Angular Momentum

    DOE R&D Accomplishments Database

    Schwinger, J.

    1952-01-26

    The commutation relations of an arbitrary angular momentum vector can be reduced to those of the harmonic oscillator. This provides a powerful method for constructing and developing the properties of angular momentum eigenvectors. In this paper many known theorems are derived in this way, and some new results obtained. Among the topics treated are the properties of the rotation matrices; the addition of two, three, and four angular momenta; and the theory of tensor operators.

  19. 78 FR 57671 - PacWest Equities, Inc.; Order of Suspension of Trading

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... COMMISSION PacWest Equities, Inc.; Order of Suspension of Trading September 17, 2013. It appears to the... securities of PacWest Equities, Inc. (``PacWest'') because of questions regarding the accuracy of assertions by PacWest in public statements regarding the company's business operations and assets. PacWest,...

  20. Evaluation of a generic RIS-PACS interface

    NASA Astrophysics Data System (ADS)

    Soehlke, Karen; Fisher, Paul D.

    1992-07-01

    An interface between a Radiology Information System (RIS) and a Picture Archiving and Communication System (PACS) has been designed in Victoria. A prototype has been developed for a Health Care Systems Inc. RIS and a Siemens PACS. The main design objective for this prototype was to create a generic RIS-PACS interface. The portability of the interface is ensured by its modularity, the utilization of a standardized language and communication protocols and the face that no changes were required to either RIS or PACS. In the case of the prototype the communication of data is unidirectional, i.e. 36 data elements are exported from RIS to PACS. Although full integration of these two information systems in the Medical Imaging department appears more desirable than interfacing, an efficient, slim RIS-PACS interface is usually the more feasibly option. Current PACS projects have to cope with the restrictions of today''s RIS and PACS, which are often not transaction-oriented, rarely use modern database models and have been designed neglecting interfacing considerations. The paper summarizes interconnection experiences of four other international projects, outlines the design of the Generic RIMS-PACS Interface and evaluates the experience with the Victoria prototype.

  1. Critical success factors for a hospital-wide PACS.

    PubMed Central

    Schrader, U.; Kotter, E.; Pelikan, E.; Zaiss, A.; Timmermann, U.; Klar, R.

    1997-01-01

    Since 1996 a picture archiving and communications system (PACS) is installed at the university hospital of Freiburg. The PACS is integrated in the hospital information system (HIS) and several modalities of different vendors are attached to it. During the implementation phase three critical factors to the success of our PACS installation where identified: the support of the workflow, the interface of the radiological information system (RIS) to the modalities, and the security policy to allow hospital-wide access to the images and results in the PACS. PMID:9357664

  2. Why do cost-benefit studies of PACS disagree?

    NASA Astrophysics Data System (ADS)

    van Gennip, Elisabeth M.; Ottes, Fenno P.; van Poppel, Bas M.; Andriessen, J. H. T. H.

    1990-08-01

    Once the technical difficulties of PACS have been solved, the main obstacle for its introductionwill be its costs. Even though PACS is still under development, it is clear that the equipment for PACS will be much more expensive than the equipment used in the conventional situation. PACS may, however, pay itself back by allowing savings of film, space and personnel. The conclusions of some recent cost-benefit studies disagree on the costs and benefits of PACS. Some conclude that PACS would pay for itself, whereas according to others PACS would be (much) more expensive. We analyzed the latest cost-benefit studies, to find out why their outcomes diverge. The comparison of the results revealed striking differences. The calculations of the annual costs of a hospital wide PACS varied between 2 and 4 million dollars. These differences could not be explained by differences in the size of the hospitals, as indicated by the number of examinations. They were, in part, caused by the fact that the costs per piece of equipment, material or space varied per study. For instance the costs of 1 square foot of (archive) space varied from 10 to 140 per year. The variation in the given costs of the film based system, depended on the fact whether the time spent by medical personnel on film management was taken into account. The differences among these studies demonstrate clearly the need for uniform, well-defined criteria for the calculation of the costs and savings of PACS.

  3. Managed PACS operation with an automatic monitoring tool

    NASA Astrophysics Data System (ADS)

    Zhang, Jianguo; Han, Ruolin; Wu, Dongqing; Zhang, Xiaoyan; Zhuang, Jun; Feng, Jie; Wang, Mingpeng; Zhang, Guozhen; Wang, Cuanfu

    2002-05-01

    Huadong hospital in Shanghai with 800 beds provides health care services for inpatients and outpatients, as well as special senior and VIP patients. In order to move to digital imaging based radiology practice, and also provide better intra-hospital consultation services for senior and VIP patients, we started to implement PACS for hospital wide services from 1999, and also designed and developed an automatic monitoring system (AMS) to monitor and control PACS operation and dataflow to decrease the total cost of ownership for PACS operation. We installed the AMS on top of the Huadong Hospital PACS in the May of 2001. The installation was painless, did not interrupt the normal PACS operation, and took only one month. The PACS administrators with the AMS can now monitor and control the entire PACS operation in real time, and also track patient and image data flow automatically. These features make administrators take proper action even before user's complaint if any failure happened in any PACS component or process, they reduce the size of the management team, and decrease total cost of PACS ownership.

  4. Effect of powdered activated carbon (PAC) on MBR performance and effluent trihalomethane formation: At the initial stage of PAC addition.

    PubMed

    Gao, Yue; Ma, Defang; Yue, Qinyan; Gao, Baoyu; Huang, Xia

    2016-09-01

    In this study, the MBR was used to treat municipal wastewater for reuse. Effects of powdered activated carbon (PAC) addition on MBR system in terms of effluent water quality, trihalomethane (THM) formation and membrane organic fouling tendency of MBR sludge supernatant at the initial stage of PAC addition were investigated. Effects of chlorine dose and contact time on THM formation and speciation were also studied. PAC addition enhanced the removal of organic matters, especially aromatic components, which improved the UV254 removal rate from 34% to 83%. PAC addition greatly reduced the membrane organic fouling tendency of MBR sludge supernatant. PAC addition reduced the MBR effluent trihalomethane formation potential (THMFP) from 351.29 to 241.95μg/L, while increased THM formation reactivity by 42%. PAC addition enhanced the formation of higher toxic bromine-containing THMs. High chlorine dose and contact time resulted in higher THM formation but lower proportion of bromine-containing THMs. PMID:27318162

  5. PAC91 - PROPERTIES AND COEFFICIENTS 1991

    NASA Technical Reports Server (NTRS)

    Mcbride, B. J.

    1994-01-01

    The two principal functions of PAC91 are to provide a means of generating theoretical thermodynamic functions from molecular constant data and to supply a means of fitting these functions to empirical equations by using a least-squares fit. The coefficients obtained from the fit may then be used to generate a library of thermodynamic data in a uniform and easy-to-use format for use in other computer codes. Several large compilations of selected or calculated thermodynamic data currently exist. Nevertheless, there is a continuing need for additional calculations due to the discovery of new species, the revision of existing molecular constant data and structural parameters, the need for data at temperatures other than those already published, the availability of new or revised heats of formation, dissociation or transition, and the revision of fundamental constants or atomic weights. Calculations may also be needed to compare the results of assuming various possible forms of the partition function. In addition, there is often a preference for thermodynamic data in functional rather than tabular form. In order to satisfy these needs, the PAC91 program can perform any combination of the following: (1) calculate thermodynamic functions (heat capacity, enthalpy, entropy, and Gibbs energy) for any set of 1 to 202 temperatures, (2) obtain a least-squares fit of the first three of these functions (either individually, two at a time, or all three simultaneously) for up to eight temperature intervals, and (3) calculate, as a function of temperature, heats of formation and equilibrium constants from assigned reference elements. The thermodynamic functions for ideal gases may be calculated from molecular constant data using one of several partition function variations provided by the program. For monatomic gases, one of three partition function cutoff techniques may be selected by the user, and unobserved but predicted electronic energy levels may be included by the program

  6. Angular Acceleration without Torque?

    ERIC Educational Resources Information Center

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

  7. Cosmological perturbations in unimodular gravity

    SciTech Connect

    Gao, Caixia; Brandenberger, Robert H.; Cai, Yifu; Chen, Pisin E-mail: rhb@hep.physics.mcgill.ca E-mail: chen@slac.stanford.edu

    2014-09-01

    We study cosmological perturbation theory within the framework of unimodular gravity. We show that the Lagrangian constraint on the determinant of the metric required by unimodular gravity leads to an extra constraint on the gauge freedom of the metric perturbations. Although the main equation of motion for the gravitational potential remains the same, the shift variable, which is gauge artifact in General Relativity, cannot be set to zero in unimodular gravity. This non-vanishing shift variable affects the propagation of photons throughout the cosmological evolution and therefore modifies the Sachs-Wolfe relation between the relativistic gravitational potential and the microwave temperature anisotropies. However, for adiabatic fluctuations the difference between the result in General Relativity and unimodular gravity is suppressed on large angular scales. Thus, no strong constraints on the theory can be derived.

  8. PACS: implementation in the U.S. Department of Defense

    NASA Astrophysics Data System (ADS)

    Chacko, Anna K.; Wider, Ronald; Romlein, John R.; Cawthon, Michael A.; Richardson, Ronald R., Jr.; Lollar, H. William; Cook, Jay F.; Timboe, Harold L.; Johnson, Thomas G.; Fellows, Douglas W.

    2000-05-01

    The Department of Defense has been a leader in Radiology re- engineering for the past decade. Efforts have included the development of two landmark PACS specifications (MDIS and DIN- PACS), respective vendor selection and implementation programs. A Tri-Service (Army, Navy and Air Force) Radiology re-engineering program was initiated which identified transitioning to digital imaging, PACS and teleradiology as key enabling technologies in a changing business scenario. Subsequently, the systematic adjustment of procurement process for radiological imaging equipment included a focus on specifying PACS-capable-digital imaging modalities and mini- PACS as stepping stones to make the hospitals and health clinics PACS-ready. The success of the PACS and teleradiology program in the DOD is evidenced by the near filmless operation of most Army and Air Force Medical Centers, several community hospitals and several operational teleradiology constellations. Additionally, the MDIS PACSystem has become the commercial PACS product for General Electric Medical Systems. The DOD continues to forge ahead in the PACS arena by implementing advanced configurations and operational concepts such as the VRE (Virtual Radiology Environment), the negotiation of Regional Archiving and Regional PACS Maintenance Programs. Newer regulations (HIPAA, the FDA approval of digital mammography) have been promulgated impacting the culture and conduct of our business. Incorporating their requirements at the very outset will enable us to streamline the delivery of radiology. The DOD community has embraced the information age at multiple levels. The Healthcare portion of this community with these initiatives is integrating itself into DOD's future. The future holds great possibilities, promises and challenges for the DOD PACS programs.

  9. A Comparative Time Differential Perturbed Angular Correlation Study of the Nuclear Quadrupole Interaction in HfF4·HF·2H2O Using 180mHf and 181Hf(β-)181Ta as Nuclear Probes: Is Ta an Innocent Spy?

    NASA Astrophysics Data System (ADS)

    Butz, Tilman; Das, Satyendra K.; Manzhur, Yurij

    2009-02-01

    We report on a comparative study of the nuclear quadrupole interaction of the nuclear probes 180mHf and 181Hf(β -)181Ta in HfF4・HF・2H2O using time differential perturbed angular correlations (TDPAC) at 300 K. For the first probe, assuming a Lorentzian frequency distribution, we obtained ωQ= 103(4) Mrad/s, an asymmetry parameter η = 0.68(3), a linewidth δ = 7.3(3.9)%, and full anisotropy within experimental accuracy. For the second probe, assuming a Lorentzian frequency distribution, we obtained three fractions: (1) with 56.5(7)%, ωQ= 126.64(4) Mrad/s and η = 0.9241(4) with a rather small distribution δ = 0.40(8)% which is attributed to HfF4・HF・2H2O; (2) with 4.6(4)%, ωQ = 161.7(3) Mrad/s and η = 0.761(4) assuming no line broadening which is tentatively attributed to a small admixture of Hf2OF6・H2O; (3) the remainder of 39.0(7)% accounts for a rapid loss of anisotropy and is modelled by a perturbation function with a sharp frequency multiplied by an exponential factor exp(-λ t) with λ = 0.55(2) ns-1. Whereas the small admixture of Hf2OF6・H2O escapes detection by the 180mHf probe, there is no rapid loss of roughly half the anisotropy as is the case with 181Hf(β -)181Ta. This loss could in principle be due to fluctuating electric field gradients originating from movements of nearest neighbour HF adducts and/or H2O molecules after nuclear transmutation to the foreign atom Ta which are absent for the isomeric probe. Alternatively, paramagnetic Ta ions could lead to fluctuating magnetic dipole fields which, when combined with fluctuating electric field gradients, could also lead to a rapid loss of anisotropy. In any case, Ta is not an "innocent spy" in this compound. Although 180mHf is not a convenient probe for conventional spectrometers, the use of fast digitizers and software coincidences would allow to use all γ -quanta in the stretched cascade which would greatly improve the efficiency of the spectrometer. 180mHf could also serve as a Pu

  10. Cosmological perturbations of quantum-mechanical origin and anisotropy of the microwave background

    NASA Technical Reports Server (NTRS)

    Grishchuk, L. P.

    1993-01-01

    Cosmological perturbations generated quantum mechanically (as a particular case, during inflation) possess statistical properties of squeezed quantum states. The power spectra of the perturbations are modulated and the angular distribution of the produced temperature fluctuations of the cosmic microwave background radiation is quite specific. An exact formula is derived for the angular correlation function of the temperature fluctuations caused by squeezed gravitational waves. The predicted angular pattern can, in principle, be revealed by observations like those by the Cosmic Background Explorer.

  11. 75 FR 80082 - State, Local, Tribal, And Private Sector Policy Advisory Committee (SLTPS-PAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-21

    ... Policy Advisory Committee (SLTPS-PAC) AGENCY: Information Security Oversight Office, National Archives... Private Sector Policy Advisory Committee (SLTPS-PAC). The SLTPS-PAC will advise the President,...

  12. PACS and multimodality in medical imaging.

    PubMed

    D'Asseler, Y; Koole, M; Van Laere, K; Vandenberghe, S; Bouwens, L; Van de Walle, R; Van de Wiele, C; Lemahieu, I; Dierckx, R A

    2000-01-01

    A PACS (Picture Archiving and Communication System) is a system that is able to store, exchange, display and manipulate images and associated diagnoses from any modality within a hospital in a timely and cost-effective way. Several developments, such as the DICOM standard, fast and convenient networking, and new storage solutions for large amounts of data, make the setup of such a PACS system possible. As the information acquired with various imaging modalities is then available and often complementary, it is desirable for the clinician to have a point-by-point spatial co-registration of images from different modalities in order to enable a synergistic use of the multimodality imaging of a patient for increased diagnostic accuracy. Various types of algorithms are available for the matching of medical images from the same or from different modalities. Co-registration algorithms based on voxel properties consist of a similarity or dissimilarity measure and an iterative or non-iterative method minimizing the dissimilarity or maximizing the similarity between the two images by a transformation of one image relative to the other. PMID:10942990

  13. PACS component testing: beta and acceptance testing

    NASA Astrophysics Data System (ADS)

    Honeyman-Buck, Janice C.; Frost, Meryll M.; Staab, Edward V.

    1997-05-01

    The functionality and performance expectations of all PACS components must be specified at the time of purchase and tested completely upon delivery to assure customer satisfaction and successful adoption of the new technology. This process may be more elaborate if the customer agrees to serve as a Beta test site for a new component or a new revision of an existing component.A carefully designed test plan will save time at installation, will allow the customer and vendor to agree on expectations, and will assure that the installation will proceed as planned. This paper describes the test procedure used at the University of Florida to accept each PACS component, either a commercial product, or one developed in house. A set of documents contain descriptions of the pre-installation environment, sets of studies to be used in the test, installation checklist, functional usage reports, subjective evaluations, and problem reporting forms. Training and user documentation is also reviewed and 'help lists' are created to help users perform the most common functions. Although details in the documents are changed to match the type of component being tested, the general form of the test remains the same. A formal procedure for testing the functionality and performance of new equipment can save time for both the vendor and the customer and, if specified at the time of purchase, can serve to document the expectations of the customer. Following these procedures will assure a successful installation and improve customer satisfaction.

  14. Predicting clinical image delivery time by monitoring PACS queue behavior.

    PubMed

    King, Nelson E; Documet, Jorge; Liu, Brent

    2006-01-01

    The expectation of rapid image retrieval from PACS users contributes to increased information technology (IT) infrastructure investments to increase performance as well as continuing demands upon PACS administrators to respond to "slow" system performance. The ability to provide predicted delivery times to a PACS user may curb user expectations for "fastest" response especially during peak hours. This, in turn, could result in a PACS infrastructure tailored to more realistic performance demands. A PACS with a stand-alone architecture under peak load typically holds study requests in a queue until the DICOM C-Move command can take place. We investigate the contents of a stand-alone architecture PACS RetrieveSend queue and identified parameters and behaviors that enable a more accurate prediction of delivery time. A prediction algorithm for studies delayed in a stand-alone PACS queue can be extendible to other potential bottlenecks such as long-term storage archives. Implications of a queue monitor in other PACS architectures are also discussed.

  15. Building PACs: A Guide for Title I Principals.

    ERIC Educational Resources Information Center

    Druian, Janice; Sayers, Susan

    This inservice program for principals was designed to assist the development and maintenance of effective Parent Advisory Councils (PACs), as mandated by Title I of the Elementary and Secondary Education Act. The manual first introduces the concept of the principal as a facilitator, outlining the principal's role and responsibilities within a PAC.…

  16. P.A.C. Training Guide = Guia de Entrenamiento.

    ERIC Educational Resources Information Center

    Colorado Migrant Education Resource Center (CoMerc), Longmont.

    Intended to give Parent Advisory Council (PAC) members exposure to their roles and responsibilities, the guide, written in Spanish and English, provides information on how to train PAC members on parliamentary procedures (Roberts Rules) and the importance of agendas and agenda construction. The guide's eight sections cover the rules/regulations,…

  17. Perturbative QUANTUM GRAVITY

    NASA Astrophysics Data System (ADS)

    't Hooft, Gerard

    2003-12-01

    A good understanding of Perturbative Quantum Gravity is essential for anyone who wishes to proceed towards any kind of non-perturbative approach. This lecture is a brief resumé of the main features of the perturbative regime.

  18. Effect of PAC dosage in a pilot-scale PAC-MBR treating micro-polluted surface water.

    PubMed

    Hu, Jingyi; Shang, Ran; Deng, Huiping; Heijman, Sebastiaan G J; Rietveld, Luuk C

    2014-02-01

    To address the water scarcity issue and advance the traditional drinking water treatment technique, a powdered activated carbon-amended membrane bioreactor (PAC-MBR) is proposed for micro-polluted surface water treatment. A pilot-scale study was carried out by initially dosing different amounts of PAC into the MBR. Comparative results showed that 2g/L performed the best among 0, 1, 2 and 3g/L PAC-MBR regarding organic matter and ammonia removal as well as membrane flux sustainability. 1g/L PAC-MBR exhibited a marginal improvement in pollutant removal compared to the non-PAC system. The accumulation of organic matter in the bulk mixture of 3g/L PAC-MBR led to poorer organic removal and severer membrane fouling. Molecular weight distribution of the bulk liquid in 2g/L PAC-MBR revealed the synergistic effects of PAC adsorption/biodegradation and membrane rejection on organic matter removal. Additionally, a lower amount of soluble extracellular polymer substances in the bulk can be secured in 21 days operation.

  19. Effect of PAC dosage in a pilot-scale PAC-MBR treating micro-polluted surface water.

    PubMed

    Hu, Jingyi; Shang, Ran; Deng, Huiping; Heijman, Sebastiaan G J; Rietveld, Luuk C

    2014-02-01

    To address the water scarcity issue and advance the traditional drinking water treatment technique, a powdered activated carbon-amended membrane bioreactor (PAC-MBR) is proposed for micro-polluted surface water treatment. A pilot-scale study was carried out by initially dosing different amounts of PAC into the MBR. Comparative results showed that 2g/L performed the best among 0, 1, 2 and 3g/L PAC-MBR regarding organic matter and ammonia removal as well as membrane flux sustainability. 1g/L PAC-MBR exhibited a marginal improvement in pollutant removal compared to the non-PAC system. The accumulation of organic matter in the bulk mixture of 3g/L PAC-MBR led to poorer organic removal and severer membrane fouling. Molecular weight distribution of the bulk liquid in 2g/L PAC-MBR revealed the synergistic effects of PAC adsorption/biodegradation and membrane rejection on organic matter removal. Additionally, a lower amount of soluble extracellular polymer substances in the bulk can be secured in 21 days operation. PMID:24412856

  20. Plasmons carrying orbital angular momentum in quantum plasmas

    NASA Astrophysics Data System (ADS)

    Khan, Shabbir A.; Ali, S.; Mendonca, J. T.; Mendonca

    2013-10-01

    The existence of plasmons with orbital angular momentum due to the Laguerre-Gaussian-type density and potential perturbations is studied in an unmagnetized quantum plasma. Starting from appropriate hydrodynamic equations for the electrostatic electron dynamics, a dispersion equation is derived in paraxial approximation. The Laguerre-Gaussian beam solutions are obtained and the properties of electric field components, energy flux, and corresponding angular momentum density of plasmons are investigated. The electric field lines are found to form helical structures with a dominant axial component. The results are analyzed numerically and the influence of radial and angular mode numbers on potential and electric field components is illustrated.

  1. Angular velocity discrimination

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.

    1990-01-01

    Three experiments designed to investigate the ability of naive observers to discriminate rotational velocities of two simultaneously viewed objects are described. Rotations are constrained to occur about the x and y axes, resulting in linear two-dimensional image trajectories. The results indicate that observers can discriminate angular velocities with a competence near that for linear velocities. However, perceived angular rate is influenced by structural aspects of the stimuli.

  2. Pituitary Adenylate Cyclase-activating Polypeptide (PACAP)/PAC1HOP1 Receptor Activation Coordinates Multiple Neurotrophic Signaling Pathways

    PubMed Central

    May, Victor; Lutz, Eve; MacKenzie, Christopher; Schutz, Kristin C.; Dozark, Kate; Braas, Karen M.

    2010-01-01

    MAPK and Akt pathways are predominant mediators of trophic signaling for many neuronal systems. Among the vasoactive intestinal peptide/secretin/glucagon family of related peptides, pituitary adenylate cyclase-activating polypeptide (PACAP) binding to specific PAC1 receptor isoforms can engage multiple signaling pathways and promote neuroprotection through mechanisms that are not well understood. Using a primary sympathetic neuronal system, the current studies demonstrate that PACAP activation of PAC1HOP1 receptors engages both MAPK and Akt neurotrophic pathways in an integrated program to facilitate neuronal survival after growth factor withdrawal. PACAP not only stimulated prosurvival ERK1/2 and ERK5 activation but also abrogated SAPK/JNK and p38 MAPK signaling in parallel. In contrast to the potent and rapid effects of PACAP in ERK1/2 phosphorylation, PACAP stimulated Akt phosphorylation in a late phase of PAC1HOP1 receptor signaling. From inhibitor and immunoprecipitation analyses, the PACAP/PAC1HOP1 receptor-mediated Akt responses did not represent transactivation mechanisms but appeared to depend on Gαq/phosphatidylinositol 3-kinase γ activity and vesicular internalization pathways. Phosphatidylinositol 3-kinase γ-selective inhibitors blocked PACAP-stimulated Akt phosphorylation in primary neuronal cultures and in PAC1HOP1-overexpressing cell lines; RNA interference-mediated knockdown of the receptor effectors attenuated PACAP-mediated Akt activation. Similarly, perturbation of endocytic pathways also blocked Akt phosphorylation. Between ERK and Akt pathways, PACAP-stimulated Akt signaling was the primary cascade that attenuated cultured neuron apoptosis after growth factor withdrawal. The partitioning of PACAP-mediated Akt signaling in endosomes may be a key mechanism contributing to the high spatial and temporal specificity in signal transduction necessary for survival pathways. PMID:20093365

  3. Novel class of highly selective divanillin-based PACs

    NASA Astrophysics Data System (ADS)

    Medina, Arturo N.; Ferreira, Lawrence; Tadros, Sobhy P.; Sizensky, Joseph J.; Fregeolle, M.; Blakeney, Andrew J.; Toukhy, Medhat A.

    1996-06-01

    A new class of diazonaphthoquinone (DNQ) photoactive compounds (PACs) based on the divanillin core is introduced in this paper. The general structure of these PAC backbones is shown in Formula 1. The divanillin structure possesses unique electronic characteristics which influence its DNQ-SO2Cl esterification reactions to be highly selective. The most reactive site for esterification in Formula 1 is one of the divanillin hydroxyls despite the typically higher steric hindrance. Surprisingly, the esterification product is then significantly deactivated towards esterification at the other previously equivalent divanillin OH. The result of using 3 equivalents of DNQ-SO2Cl to esterify tetraphenolic species is the formation of high percentages of the specific triester in which the second divanillyl OH remains unesterified. The deactivation of the second divanillin OH after the initial esterification indicates some interaction between the two o,o-biphenol rings despite its inability to be coplanar for conjugation of (pi) electrons because of steric hindrance. Possible explanations for this interaction are explored using molecular simulation tools. Diverse members of the divanillin PAC family have been prepared from phenols of varying structure and hydrophobicities. These PACs were tested lithographically and the results correlated with PAC backbone structure. The characteristic dissolution rate behavior of the resist formulations based on triesterified PACs, measured as a function of exposure dose, generally show high discrimination and strong inhibition, even with the more hydrophilic PACs. These formulations typically exhibited high resolution, wide focus latitude, and exposure margins greater than 2.0 in lithographic screening.

  4. Time and flow study for technology assessment of PACS

    NASA Astrophysics Data System (ADS)

    Satoh, Katsumi; Umeda, Tokuo; Inamura, Kiyonari; Hasegawa, Toshitsune; Kondoh, Hiroshi; Mori, Yoshinobu; Ikezoe, Junpei; Kozuka, Takahiro

    1994-05-01

    Quantitative description of the value of Picture Archiving and Communication System (PACS) in the health care environment is essential to assess the benefits with which PACS provides us. It is necessary to obtain data related to our film-based system before PACS installation in order to make quantitative comparison of before-and-after PACS operation, so that we can assess the clinical effectiveness brought by the PACS itself. We conducted flow study to acquire the whole chart of data flow related to radiological examination. And then defined the parameters and employed them to conduct time study for measuring several items concerning order entry, report making and image delivery at outpatient clinics and wards of eight departments using stopwatches, IC cards and time-recorders. This paper describes the results of measurement. For example, the location of each clinic/ward affected the time spent for images/reports delivery, and that hand writing time occupies more than half of the time required for making a single diagnostic report in 16 percent of cases. These results indicate that acceptability by medical staff is the key to successful operation of PACS. For instance, simple man-machine interaction at image display workstation must be properly realized. By using the same parameters mentioned above, we can compare those data with the results measured after PACS operation in a few years.

  5. PacCYP707A2 negatively regulates cherry fruit ripening while PacCYP707A1 mediates drought tolerance.

    PubMed

    Li, Qian; Chen, Pei; Dai, Shengjie; Sun, Yufei; Yuan, Bing; Kai, Wenbin; Pei, Yuelin; He, Suihuan; Liang, Bin; Zhang, Yushu; Leng, Ping

    2015-07-01

    Sweet cherry is a non-climacteric fruit and its ripening is regulated by abscisic acid (ABA) during fruit development. In this study, four cDNAs (PacCYP707A1-4) encoding 8'-hydroxylase, a key enzyme in the oxidative catabolism of ABA, were identified in sweet cherry fruits using tobacco rattle virus-induced gene silencing (VIGS) and particle bombardment approaches. Quantitative real-time PCR confirmed significant down-regulation of target gene transcripts in VIGS-treated cherry fruits. In PacCYP707A2-RNAi-treated fruits, ripening and fruit colouring were promoted relative to control fruits, and both ABA accumulation and PacNCED1 transcript levels were up-regulated by 140%. Silencing of PacCYP707A2 by VIGS significantly altered the transcripts of both ABA-responsive and ripening-related genes, including the ABA metabolism-associated genes NCED and CYP707A, the anthocyanin synthesis genes PacCHS, PacCHI, PacF3H, PacDFR, PacANS, and PacUFGT, the ethylene biosynthesis gene PacACO1, and the transcription factor PacMYBA. The promoter of PacMYBA responded more strongly to PacCYP707A2-RNAi-treated fruits than to PacCYP707A1-RNAi-treated fruits. By contrast, silencing of PacCYP707A1 stimulated a slight increase in fruit colouring and enhanced resistance to dehydration stress compared with control fruits. These results suggest that PacCYP707A2 is a key regulator of ABA catabolism that functions as a negative regulator of fruit ripening, while PacCYP707A1 regulates ABA content in response to dehydration during fruit development. PMID:25956880

  6. PacCYP707A2 negatively regulates cherry fruit ripening while PacCYP707A1 mediates drought tolerance

    PubMed Central

    Li, Qian; Chen, Pei; Dai, Shengjie; Sun, Yufei; Yuan, Bing; Kai, Wenbin; Pei, Yuelin; He, Suihuan; Liang, Bin; Zhang, Yushu; Leng, Ping

    2015-01-01

    Sweet cherry is a non-climacteric fruit and its ripening is regulated by abscisic acid (ABA) during fruit development. In this study, four cDNAs (PacCYP707A1–4) encoding 8′-hydroxylase, a key enzyme in the oxidative catabolism of ABA, were identified in sweet cherry fruits using tobacco rattle virus-induced gene silencing (VIGS) and particle bombardment approaches. Quantitative real-time PCR confirmed significant down-regulation of target gene transcripts in VIGS-treated cherry fruits. In PacCYP707A2-RNAi-treated fruits, ripening and fruit colouring were promoted relative to control fruits, and both ABA accumulation and PacNCED1 transcript levels were up-regulated by 140%. Silencing of PacCYP707A2 by VIGS significantly altered the transcripts of both ABA-responsive and ripening-related genes, including the ABA metabolism-associated genes NCED and CYP707A, the anthocyanin synthesis genes PacCHS, PacCHI, PacF3H, PacDFR, PacANS, and PacUFGT, the ethylene biosynthesis gene PacACO1, and the transcription factor PacMYBA. The promoter of PacMYBA responded more strongly to PacCYP707A2-RNAi-treated fruits than to PacCYP707A1-RNAi-treated fruits. By contrast, silencing of PacCYP707A1 stimulated a slight increase in fruit colouring and enhanced resistance to dehydration stress compared with control fruits. These results suggest that PacCYP707A2 is a key regulator of ABA catabolism that functions as a negative regulator of fruit ripening, while PacCYP707A1 regulates ABA content in response to dehydration during fruit development. PMID:25956880

  7. A UNIFIED THEORY FOR THE EFFECTS OF STELLAR PERTURBATIONS AND GALACTIC TIDES ON OORT CLOUD COMETS

    SciTech Connect

    Collins, Benjamin F.; Sari, Re'em

    2010-11-15

    We examine the effects of passing field stars on the angular momentum of a nearly radial orbit of an Oort cloud comet bound to the Sun. We derive the probability density function of the change in angular momentum from one stellar encounter, assuming a uniform and isotropic field of perturbers. We show that the total angular momentum follows a Levy flight, and determine its distribution function. If there is an asymmetry in the directional distribution of perturber velocities, the marginal probability distribution of each component of the angular momentum vector can be different. The constant torque attributed to Galactic tides arises from a non-cancellation of perturbations with an impact parameter of order the semimajor axis of the comet. When the close encounters are rare, the angular momentum is best modeled by the stochastic growth of stellar encounters. If trajectories passing between the comet and the Sun occur frequently, the angular momentum exhibits the coherent growth attributed to the Galactic tides.

  8. Hyperfine Magnetic Field Measurements in the Heusler Alloys COBALT(2)-TITANIUM-Z, COBALT(2)-MAGNESIUM-Z (z = Silicon, Germanium, and Tin) and COBALT(2)-MAGNESIUM- Gallium Using the Moessbauer Effect (me) and the Time Differential Perturbed Angular Correlation (tdpac) Techniques

    NASA Astrophysics Data System (ADS)

    Lahamer, Amer Said

    1990-01-01

    Measurements of the hyperfine magnetic field in a series of Heusler alloys were performed. The probes were in (^{119}Sn) and cadmium (^{111}Cd). These measurements were performed at the University of Cincinnati in Cincinnati, Ohio. Two techniques were used. The first technique was the Mossbauer effect, which was used to measure the hyperfine magnetic field on ^{119 }Sn in Co_2TiZ (Z = Si, Ge, and Sn), and the second technique was the Time Differential Perturbed Angular Correlation which was used to measure the hyperfine magnetic field on ^ {111}Cd in the Co_2MnZ (Z = Si, Ge, Sn, and Ga). The probes are expected to go to the Z sites of the alloys. The hyperfine magnetic field measurements on ^{119}Sn in Co _2TiZ (Z = Si, Ge, and Sn) alloys were done at room, dry ice and liquid nitrogen temperatures by using the Mossbauer effect technique. The data were fitted by using a least squares fit from which three parameters were extracted. These parameters are the isomer shift, the quadrupole splitting and the hyperfine magnetic field. Temperature variation measurements of the hyperfine magnetic field were performed on ^{111 }Cd in Co_2MnZ (Z = Si, Ge, Sn, and Ga) alloys. The data were fitted again by using a least squares fit from which the Larmor frequency which is related to the hyperfine magnetic field was extracted. Also the Fourier Transforms were taken of the data, on the one hand to confirm the results of the least squares fit and on the other hand to look for more frequencies. Results of the Fourier Transforms show that some of the probe, ^{111}In, did go to the Co site in the Co_2MnZ (Z = Ga, Si, and Ge) alloys. The hmf on ^{111 }Cd in the Co site of these alloys is found to be 68 kOe which is consistent with the value found in the literature. Two theoretical models were examined for the trends of hyperfine magnetic field on ^{119 }Sn and ^{111}Cd in Co_2MnZ (Z = Si, Ge, Sn, and Ga) alloys. These are the Campbell and Blandin model and the Stearns' overlap model

  9. Disaster-hardened imaging POD for PACS

    NASA Astrophysics Data System (ADS)

    Honeyman-Buck, Janice; Frost, Meryll

    2005-04-01

    operated on emergency power, a limited, but effective number of studies could be performed. However, in a digital department, there is a reliance on the network infrastructure to deliver images to viewing locations. The system developed for our institution uses several imaging PODS, a name we chose because it implied to us a safe, contained environment. Each POD is on both the standard and the emergency power systems. All the vendor equipment that produces images is on a private, stand-alone network controlled either by a simple or a managed switch. Included in each POD is a dry-process DICOM printer that is rarely used during normal operations and a display workstation. One node on the private network is a PACS application processor (AP) with two network interface cards, one for the private network, one for the standard PACS network. During ordinary daily operations, all acquired images pass through this AP and are routed to the PACS archives, web servers, and workstations. However, if the power and network to much of the hospital were to fail, the stand-alone POD could still function. Images are routed to the AP, but cannot forward to the main network. However, they can be routed to the printer and display in the POD. They are also stored on the AP to continue normal routing when the infrastructure is restored. Results: The imaging PODS have been tested in actual disaster testing where the infrastructure was intentionally removed and worked as designed. To date, we have not had to use them in a real-life scenario and we hope we never do, but we feel we have a reasonable level of emergency imaging capability if we ever need it. Conclusions: Our testing indicates our PODS are a viable way to continue medical imaging in the face of an emergency with a major part of our network and electrical infrastructure destroyed.

  10. Association of the implementation of PACS with hospital revenue.

    PubMed

    Kim, Sang A; Park, Woong-Sub; Chun, Tong Jin; Mo Nam, Chung

    2002-12-01

    The purpose of this study is to assess the association of implementation of PACS with the inpatient and outpatient revenue of a general hospital. The authors analyzed the in- and outpatient revenue data of all general hospitals (212) in South Korea obtained from the Korean National Health Insurance Corporation (KNHIC) during the period from 1996 through 1999 using the mixed model for repeated measure data. The following variables were used in the analysis: status of picture archiving and communication systems (PACS) implementation, population size, state of competition, inhabitant's income, hospital location, hospital size, whether a tertiary hospital, whether public or private, the effect of year. The revenues from both in- and outpatient departments were significantly higher one year after the introduction of PACS while controlling for the confounding variables. Although the causality needs to be clarified, the implementation of PACS was correlated significantly to the increased amount of inpatient and outpatient revenue.

  11. NARSTO PAC2001 LANGLEY GAS PM MET DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO PAC2001 LANGLEY GAS PM MET DATA Project Title:  NARSTO Discipline:  ... Chemiliminescence GC-MS Ion Chromatograph Pressure Sensor Temperature Probe Humidity Sensor Wind Sensor UV Ozone Detector ...

  12. Unveiling Angular Momentum

    NASA Astrophysics Data System (ADS)

    Robinson, Stephen

    2015-03-01

    Angular momentum is a notoriously difficult concept to grasp. Visualization often requires three-dimensional pictures of vectors pointing in seemingly arbitrary directions. A simple student-run laboratory experiment coupled with intuitive explanations by an instructor can clear up some of the inherent ambiguity of rotational motion. Specifically, the precessional period of a suspended spinning bicycle wheel can be related to the spinning frequency through a simple algebraic expression. An explanation of this precession apart from the concept of angular momentum will be given.

  13. Angular shear plate

    SciTech Connect

    Ruda, Mitchell C.; Greynolds, Alan W.; Stuhlinger, Tilman W.

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  14. Why PACS is no longer a four-letter word.

    PubMed

    Chopra, R M

    2000-01-01

    The real value of PACS is not realized until widespread adoption exists among physicians other than interpreting radiologists. Referring physicians at the office level, in the operating room and in other departments must be willing to embrace the reading of images on monitors. That takes time. The payoff for a PACS system is therefore not realized until sometime in the future. Given the huge up-front capital expenditure required of PACS solutions, it is no wonder that the decision has historically been a difficult one to make. Enter the application service provider (ASP). The marriage of the ASP model to PACS seems to be one of the true "killer apps" currently available in the healthcare technology space. An ASP can host and maintain the software inherent in PACS solutions. Images are centrally archived over the short-, medium-, and long-term timeframe, utilizing state-of-art data management facilities. Some ASPs also provide the necessary bandwidth to office sites and the small amount of hardware that is required onsite, such as viewing stations or monitors. Costs for Internet-based image management under the ASP model rely on a pay-as-you-go formula, which may include all software, support, required hardware and bandwidth as part of the service. There may be a minor up-front fee for installation. The ASP pricing model eliminates the huge gamble an organization takes on "big iron" PACS purchases. Those benefits rely on the first rule of finance: a dollar today is worth more than a dollar tomorrow. PACS and ASPs were made for one another. Because the financial benefits of PACS are realized over time, the timing of cash flows is extremely important. Other benefits inherent in the ASP model such as scalability, diminished need for IT personnel, software version integrity and better pricing because of economies of scale are attractive also.

  15. Transient effects in Herschel/PACS spectroscopy

    NASA Astrophysics Data System (ADS)

    Fadda, Dario; Jacobson, Jeffery D.; Appleton, Philip N.

    2016-10-01

    Context. The Ge:Ga detectors used in the PACS spectrograph onboard the Herschel space telescope react to changes of the incident flux with a certain delay. This generates transient effects on the resulting signal which can be important and last for up to an hour. Aims: The paper presents a study of the effects of transients on the detected signal and proposes methods to mitigate them especially in the case of the unchopped mode. Methods: Since transients can arise from a variety of causes, we classified them in three main categories: transients caused by sudden variations of the continuum due to the observational mode used; transients caused by cosmic ray impacts on the detectors; transients caused by a continuous smooth variation of the continuum during a wavelength scan. We propose a method to disentangle these effects and treat them separately. In particular, we show that a linear combination of three exponential functions is needed to fit the response variation of the detectors during a transient. An algorithm to detect, fit, and correct transient effects is presented. Results: The solution proposed to correct the signal for the effects of transients substantially improves the quality of the final reduction with respect to the standard methods used for archival reduction in the cases where transient effects are most pronounced. Conclusions: The programs developed to implement the corrections are offered through two new interactive data reduction pipelines in the latest releases of the Herschel Interactive Processing Environment.

  16. Do cosmological perturbations have zero mean?

    SciTech Connect

    Armendariz-Picon, Cristian

    2011-03-01

    A central assumption in our analysis of cosmic structure is that cosmological perturbations have a constant ensemble mean, which can be set to zero by appropriate choice of the background. This property is one of the consequences of statistical homogeneity, the invariance of correlation functions under spatial translations. In this article we explore whether cosmological perturbations indeed have zero mean, and thus test one aspect of statistical homogeneity. We carry out a classical test of the zero mean hypothesis against a class of alternatives in which primordial perturbations have inhomogeneous non-vanishing means, but homogeneous and isotropic covariances. Apart from Gaussianity, our test does not make any additional assumptions about the nature of the perturbations and is thus rather generic and model-independent. The test statistic we employ is essentially Student's t statistic, applied to appropriately masked, foreground-cleaned cosmic microwave background anisotropy maps produced by the WMAP mission. We find evidence for a non-zero mean in a particular range of multipoles, but the evidence against the zero mean hypothesis goes away when we correct for multiple testing. We also place constraints on the mean of the temperature multipoles as a function of angular scale. On angular scales smaller than four degrees, a non-zero mean has to be at least an order of magnitude smaller than the standard deviation of the temperature anisotropies.

  17. Learn from experience: insights of 200+ PACS customers.

    PubMed

    Swaton, Norm

    2002-01-01

    This article is based on a PACS study published in June 2001 by KLAS Enterprises. The study offers unique insight into the performance, underlying technology, product depth and breadth, and "real world" issues facing 10 of the leading PACS vendors and their clients as rated at more than 200 of their client sites by CIOs, department directors and vendor executives. The driving force behind this report reflects the heightened interest in PACS systems in general and PACS' contributions to the benefits associated with an electronic medical record. This research was sponsored by 10 healthcare provider organizations (not vendors), ranging from a 150-bed acute-care hospital to a seven-hospital IDN. Most of the data in the report focuses on the use of PACS in the radiology department, since comparatively few sites are using PACS systems in other departments, such as cardiology or pathology. The participating vendors supplied their customer lists, which contributed to the majority of clients surveyed. Clients surveyed in the study vary widely in size, ranging from 50 to 2,000 beds, with about 46 percent of those surveyed having a hospital size of more than 400 beds. The customers represent a broad cross-section of PACS clients, ranging from 10 percent to 95 percent filmless, with large-scale users making up the majority of respondents. Each of the customers were asked to numerically rate their vendor on 28 aspects of performance, as well as to answer 12 questions relating to customer satisfaction. Based on study results, success with PACS can be distilled into some basic principles. There are other issues that will help with a successful PACS selection and implementation, but the following list should help anyone get started. If you are able to focus on and accomplish these few things, you stand a better chance of building and meeting your business case. Pre-sell your PACS concept to the radiologists, technicians, IS/IT staff supporting it and to the referring physicians

  18. Learn from experience: insights of 200+ PACS customers.

    PubMed

    Swaton, Norm

    2002-01-01

    This article is based on a PACS study published in June 2001 by KLAS Enterprises. The study offers unique insight into the performance, underlying technology, product depth and breadth, and "real world" issues facing 10 of the leading PACS vendors and their clients as rated at more than 200 of their client sites by CIOs, department directors and vendor executives. The driving force behind this report reflects the heightened interest in PACS systems in general and PACS' contributions to the benefits associated with an electronic medical record. This research was sponsored by 10 healthcare provider organizations (not vendors), ranging from a 150-bed acute-care hospital to a seven-hospital IDN. Most of the data in the report focuses on the use of PACS in the radiology department, since comparatively few sites are using PACS systems in other departments, such as cardiology or pathology. The participating vendors supplied their customer lists, which contributed to the majority of clients surveyed. Clients surveyed in the study vary widely in size, ranging from 50 to 2,000 beds, with about 46 percent of those surveyed having a hospital size of more than 400 beds. The customers represent a broad cross-section of PACS clients, ranging from 10 percent to 95 percent filmless, with large-scale users making up the majority of respondents. Each of the customers were asked to numerically rate their vendor on 28 aspects of performance, as well as to answer 12 questions relating to customer satisfaction. Based on study results, success with PACS can be distilled into some basic principles. There are other issues that will help with a successful PACS selection and implementation, but the following list should help anyone get started. If you are able to focus on and accomplish these few things, you stand a better chance of building and meeting your business case. Pre-sell your PACS concept to the radiologists, technicians, IS/IT staff supporting it and to the referring physicians

  19. Velocity perturbation distributions in the breakup of artificial satellites

    NASA Technical Reports Server (NTRS)

    Badhwar, Gautam D.; Tan, Arjun; Reynolds, Robert C.

    1990-01-01

    A method is presented for calculating the three orthogonal components of the velocity perturbations of satellite fragments, with a view to ascertaining the nature and intensity of the satellite breakup. The method employs three simultaneous equations furnished by changes in fragment specific energy, specific angular momentum, and plane orientation. Velocity perturbations are thereby calculated for fragments from 20 major satellite breakup events; these results, in conjunction with a technique for determining fragment masses, yield a description of the breakup process.

  20. Angular momentum and star formation

    NASA Astrophysics Data System (ADS)

    Strittmatter, P. A.

    The present investigation is mainly concerned with the importance of high angular resolution observations in studies of star formation and, in particular, with elucidating the role which angular momentum plays in the process. A brief report is included on recent high angular resolution observations made with the Steward Observatory speckle camera system. A consideration of the angular momentum in interstellar clouds indicates that rotation precludes quasi-spherical contraction. A number of solutions to this angular momentum problem are examined, taking into account questions concerning the help provided by high angular resolution observations for an elucidation of the various possible scenarios of star formation. Technical aspects involved in obtaining suitable data are investigated. It is concluded that high angular resolution observations hold considerable promise for solving at least some of the problems associated with the role of angular momentum in star formation.

  1. Quantum Heuristics of Angular Momentum

    ERIC Educational Resources Information Center

    Levy-Leblond, Jean-Marc

    1976-01-01

    Discusses the quantization of angular momentum components, Heisenberg-type inequalities for their spectral dispersions, and the quantization of the angular momentum modulus, without using operators or commutation relations. (MLH)

  2. Density perturbation theory

    SciTech Connect

    Palenik, Mark C.; Dunlap, Brett I.

    2015-07-28

    Despite the fundamental importance of electron density in density functional theory, perturbations are still usually dealt with using Hartree-Fock-like orbital equations known as coupled-perturbed Kohn-Sham (CPKS). As an alternative, we develop a perturbation theory that solves for the perturbed density directly, removing the need for CPKS. This replaces CPKS with a true Hohenberg-Kohn density perturbation theory. In CPKS, the perturbed density is found in the basis of products of occupied and virtual orbitals, which becomes ever more over-complete as the size of the orbital basis set increases. In our method, the perturbation to the density is expanded in terms of a series of density basis functions and found directly. It is possible to solve for the density in such a way that it makes the total energy stationary even if the density basis is incomplete.

  3. OT1_rpaladin_1: PACS and SPIRE observations of Galactic anomalous emission sources.

    NASA Astrophysics Data System (ADS)

    Paladini, R.

    2010-07-01

    Despite the increasing evidence that the anomalous emission is a new physical mechanism acting in the diffuse interstellar medium, the nature and distribution of this component remains elusive. The currently most favored models attribute the observed microwave excess to rotating very small dust grains (PAHs and VSGs). Nonetheless, the infrared properties of the sources which, to date, are known to exhibit this type of emission are very poorly known mostly due to the limited angular resolution and frequency coverage of DIRBE and IRAS data. We propose HERSCHEL PACS and SPIRE mapping of three Galactic anomalous emission sources (LDN 1780, LDN 675 and LDN 1111). This data, when combined with ancillary NIR and mid-IR data of comparable angular resolution (mainly from Spitzer), and coupled with available dust models, will allow to set tight constraints on the radiation field in the emitting sources as well as in their immediate surroundings. Such constraints, in turn, will allow to estimate the abundances of PAHs, VSGs and BGs, hence to shed light on the potential link between these dust populations and the observed microwave excess.

  4. PACS and Web-based image distribution and display.

    PubMed

    Zhang, Jianguo; Sun, Jianyong; Stahl, Johannes N

    2003-01-01

    Picture archiving and communication system (PACS) delivers images to the display workstations mostly through digital image communication in medicine (DICOM) protocols in radiology departments, and there are lots of medical applications in healthcare community needing to access PACS images for different application purposes. In this paper, we first reviewed a hospital-integrated PACS image data flow and typical diagnostic display software architecture, and discussed some Web technologies and Web-based image application server architectures, as well as image accessing and viewing methods in these architectures. Then, we present one approach to develop component-based image display architecture and use image processing and display component to build a diagnostic display workstation, and also, give a method to integrate this component into Web-based image distribution server to enable users using Web browsers to access, view and manipulate PACS DICOM images as easy as with PACS display workstations. Finally, we test and evaluate the performance of image loading and displaying by using the diagnostic display workstation and the component-based Web display system, the experimental results show that the image distribution and display performance from the Web server to browser clients is similar with that of the image loading and displaying procedure of the diagnostic workstation as more browser clients accessing the Web server at same time. We also discuss the advantages and disadvantages of the Web-based image distribution and display in different medical applications.

  5. Java-based cryptosystem for PACS and tele-imaging

    NASA Astrophysics Data System (ADS)

    Tjandra, Donny; Wong, Stephen T. C.; Yu, Yuan-Pin

    1998-07-01

    Traditional PACS systems are based on two-tier client server architectures, and require the use of costly, high-end client workstations for image viewing. Consequently, PACS systems using the two-tier architecture do not scale well as data increases in size and complexity. Furthermore, use of dedicated viewing workstations incurs costs in deployment and maintenance. To address these issues, the use of digital library technologies, such as the World Wide Web, Java, and CORBA, is being explored to distribute PACS data to serve a broader range of healthcare providers in an economic and efficient manner. Integration of PACS systems with digital library technologies allows access to medical information through open networks such as the Internet. However, use of open networks to transmit medical data introduces problems with maintaining privacy and integrity of patient information. Cryptography and digital timestamping is used to protect sensitive information from unauthorized access or tampering. A major concern when using cryptography and digital timestamping is the performance degradation associated with the mathematical calculations needed to encrypt/decrypt an image dataset, or to calculate the hash value of an image. The performance issue is compounded by the extra layer associated with the CORBA middleware, and the use of programming languages interpreted at the client side, such as Java. This paper study the extent to which Java-based cryptography and digital timestamping affects performance in a PACS system integrated with digital library technologies.

  6. DICOM modality worklist: an essential component in a PACS environment.

    PubMed

    Gale, M E; Gale, D R

    2000-08-01

    The development and acceptance of the digital communication in medicine (DICOM) standard has become a basic requirement for the implementation of electronic imaging in radiology. DICOM is now evolving to provide a standard for electronic communication between radiology and other parts of the hospital enterprise. In a completely integrated filmless radiology department, there are 3 core computer systems, the picture archiving and communication system (PACS), the hospital or radiology information system (HIS, RIS), and the acquisition modality. Ideally, each would have bidirectional communication with the other 2 systems. At a minimum, a PACS must be able to receive and acknowledge receipt of image and demographic data from the modalities. Similarly, the modalities must be able to send images and demographic data to the PACS. Now that basic DICOM communication protocols for query or retrieval, storage, and print classes have become established through both conformance statements and intervendor testing, there has been an increase in interest in enhancing the functionality of communication between the 3 computers. Historically, demographic data passed to the PACS have been generated manually at the modality despite the existence of the same data on the HIS or RIS. In more current sophisticated implementations, acquisition modalities are able to receive patient and study-related data from the HIS or RIS. DICOM Modality Worklist is the missing electronic link that transfers this critical information between the acquisition modalities and the HIS or RIS. This report describes the concepts, issues, and impact of DICOM Modality Worklist implementation in a PACS environment. PMID:15359747

  7. Supercritical fluid extraction (SFE) of cranberries does not extract oligomeric proanthocyanidins (PAC) but does alter the chromatography and bioactivity of PAC fractions extracted from SFE residues.

    PubMed

    Feliciano, Rodrigo P; Meudt, Jennifer J; Shanmuganayagam, Dhanansayan; Metzger, Brandon T; Krueger, Christian G; Reed, Jess D

    2014-08-01

    Supercritical fluid extraction (SFE) removed lipophilic compounds and low molecular weight flavonoids from cranberries. However, SFE did not extract proanthocyanidins (PAC). The SFE PAC-enriched residue was submitted to fractionation on Sephadex LH-20 using ethanol, ethanol/methanol, and 80% acetone. PAC degree of polymerization (DP) and ratios of "A-type" to "B-type" interflavan bonds were compared with those of PAC fractions without SFE. Mass spectrometry showed that when SFE was used, PAC distribution was shifted toward higher DP and contained higher amounts of two and three "A-type" bonds compared to PAC fractions without SFE. The 80% acetone fraction with SFE had significantly greater extraintestinal pathogenic Escherichia coli (ExPEC) agglutination and significantly lower ExPEC invasion of enterocytes than the fraction without SFE. Cranberry PAC with higher numbers of "A-type" interflavan bonds are more bioactive in agglutinating ExPEC and inhibiting ExPEC enterocyte invasion.

  8. Sentinel-1 And Sentinel-3 OLCI PAC At DLR

    NASA Astrophysics Data System (ADS)

    Hahmann, Thomas; Weber, Hans; Diedrich, Erhard; Schreier, Gunter

    2013-12-01

    GMES / Copernicus is the European Earth Observation Programme, conducted jointly by the EC, ESA, EUMETSAT and the member states. The Sentinel satellites (Copernicus space segment) are expected to be launched in 2014 (Sentinel-1A, -2A, and -3A). The core payload data ground segment (PDGS) is managed by ESA and operated by national partners. In this core ground segment, the DLR German Remote Sensing Data Center (DFD) was selected to install and operate Processing and Archiving Centers (PACs) for Sentinel-1 and Sentinel-3-OLCI. This paper describes the current status of the project “Preparation and Operations of the Sentinel-1 and Sentinel-3 OLCI Off- line Processing and Archiving Centre at DLR Oberpfaffenhofen (S1-PAC / S3-OLCI-PAC)”.

  9. Dicoogle, a Pacs Featuring Profiled Content Based Image Retrieval

    PubMed Central

    Valente, Frederico; Costa, Carlos; Silva, Augusto

    2013-01-01

    Content-based image retrieval (CBIR) has been heralded as a mechanism to cope with the increasingly larger volumes of information present in medical imaging repositories. However, generic, extensible CBIR frameworks that work natively with Picture Archive and Communication Systems (PACS) are scarce. In this article we propose a methodology for parametric CBIR based on similarity profiles. The architecture and implementation of a profiled CBIR system, based on query by example, atop Dicoogle, an open-source, full-fletched PACS is also presented and discussed. In this solution, CBIR profiles allow the specification of both a distance function to be applied and the feature set that must be present for that function to operate. The presented framework provides the basis for a CBIR expansion mechanism and the solution developed integrates with DICOM based PACS networks where it provides CBIR functionality in a seamless manner. PMID:23671578

  10. PACS-Based Computer-Aided Detection and Diagnosis

    NASA Astrophysics Data System (ADS)

    Huang, H. K. (Bernie); Liu, Brent J.; Le, Anh HongTu; Documet, Jorge

    The ultimate goal of Picture Archiving and Communication System (PACS)-based Computer-Aided Detection and Diagnosis (CAD) is to integrate CAD results into daily clinical practice so that it becomes a second reader to aid the radiologist's diagnosis. Integration of CAD and Hospital Information System (HIS), Radiology Information System (RIS) or PACS requires certain basic ingredients from Health Level 7 (HL7) standard for textual data, Digital Imaging and Communications in Medicine (DICOM) standard for images, and Integrating the Healthcare Enterprise (IHE) workflow profiles in order to comply with the Health Insurance Portability and Accountability Act (HIPAA) requirements to be a healthcare information system. Among the DICOM standards and IHE workflow profiles, DICOM Structured Reporting (DICOM-SR); and IHE Key Image Note (KIN), Simple Image and Numeric Report (SINR) and Post-processing Work Flow (PWF) are utilized in CAD-HIS/RIS/PACS integration. These topics with examples are presented in this chapter.

  11. Automated Lattice Perturbation Theory

    SciTech Connect

    Monahan, Christopher

    2014-11-01

    I review recent developments in automated lattice perturbation theory. Starting with an overview of lattice perturbation theory, I focus on the three automation packages currently "on the market": HiPPy/HPsrc, Pastor and PhySyCAl. I highlight some recent applications of these methods, particularly in B physics. In the final section I briefly discuss the related, but distinct, approach of numerical stochastic perturbation theory.

  12. Quark Orbital Angular Momentum

    NASA Astrophysics Data System (ADS)

    Burkardt, Matthias

    2016-06-01

    Generalized parton distributions provide information on the distribution of quarks in impact parameter space. For transversely polarized nucleons, these impact parameter distributions are transversely distorted and this deviation from axial symmetry leads on average to a net transverse force from the spectators on the active quark in a DIS experiment. This force when acting along the whole trajectory of the active quark leads to transverse single-spin asymmetries. For a longitudinally polarized nucleon target, the transverse force implies a torque acting on the quark orbital angular momentum (OAM). The resulting change in OAM as the quark leaves the target equals the difference between the Jaffe-Manohar and Ji OAMs.

  13. Perturbative tests of non-perturbative counting

    NASA Astrophysics Data System (ADS)

    Dabholkar, Atish; Gomes, João

    2010-03-01

    We observe that a class of quarter-BPS dyons in mathcal{N} = 4 theories with charge vector ( Q, P) and with nontrivial values of the arithmetic duality invariant I := gcd( Q∧ P) are nonperturbative in one frame but perturbative in another frame. This observation suggests a test of the recently computed nonperturbative partition functions for dyons with nontrivial values of the arithmetic invariant. For all values of I, we show that the nonperturbative counting yields vanishing indexed degeneracy for this class of states everywhere in the moduli space in precise agreement with the perturbative result.

  14. MIRIAM: the PACS project in Paris: overview and implementation.

    PubMed

    Primo, H; Picard, J E

    1997-08-01

    In this article the authors describe the Management Informatique de la Radiologie et de l'Imagerie Médicale (MIRIAM) major picture archiving and communication system (PACS) project in Paris, France. The Assistance Publique of Paris, France is a healthcare provider and took the initiative to start the largest PACS program in Europe to date. The MIRIAM project will start in 1997 and will be used in different, consecutive phases. A consortium of several companies is in charge of the implementation. Thirty-three hospitals with 54 imaging departments will be integrated in one system.

  15. Investigation of environmental perturbations on passive asymmetric satellite

    NASA Technical Reports Server (NTRS)

    Tate, V.

    1976-01-01

    The effects of environmental perturbations on the attitude of a slow tumbling earth-oriented satellite are investigated. The environmental perturbations considered were aerodynamic drag, gravity-gradient, solar radiation pressure, and magnetic torques. The Euler attitude equations were solved numerically for the Skylab spacecraft. Results are presented for both torque-free motion and for cases in which aerodynamic and gravity-gradient torques are acting in a slow tumble mode. Simulations show gravity-gradient effects on satellite momentum to be cyclic and to increase the precession rate of the angular momentum vector about the radius vector. This also tends to align the minor axis along the radius vector. Aerodynamic drag initially decreases angular momentum, slowly precesses the momentum vector about the radius vector, and finally drives the satellite into an unstable mode. Combined gravity-gradient and aerodynamic torques reduce angular momentum and energy, and induce a steady precession rate of the momentum vector about the radius vector.

  16. Parents as Agents of Change (PAC) in pediatric weight management: The protocol for the PAC randomized clinical trial

    PubMed Central

    2012-01-01

    Background There is an urgent need to develop and evaluate weight management interventions to address childhood obesity. Recent research suggests that interventions designed for parents exclusively, which have been named parents as agents of change (PAC) approaches, have yielded positive outcomes for managing pediatric obesity. To date, no research has combined a PAC intervention approach with cognitive behavioural therapy (CBT) to examine whether these combined elements enhance intervention effectiveness. This paper describes the protocol our team is using to examine two PAC-based interventions for pediatric weight management. We hypothesize that children with obesity whose parents complete a CBT-based PAC intervention will achieve greater reductions in adiposity and improvements in cardiometabolic risk factors, lifestyle behaviours, and psychosocial outcomes than children whose parents complete a psycho-education-based PAC intervention (PEP). Methods/Design This study is a pragmatic, two-armed, parallel, single-blinded, superiority, randomized clinical trial. The primary objective is to examine the differential effects of a CBT-based PAC vs PEP-based PAC intervention on children’s BMI z-score (primary outcome). Secondary objectives are to assess intervention-mediated changes in cardiometabolic, lifestyle, and psychosocial variables in children and parents. Both interventions are similar in frequency of contact, session duration, group facilitation, lifestyle behaviour goals, and educational content. However, the interventions differ insofar as the CBT-based intervention incorporates theory-based concepts to help parents link their thoughts, feelings, and behaviours; these cognitive activities are enabled by group leaders who possess formal training in CBT. Mothers and fathers of children (8–12 years of age; BMI ≥85th percentile) are eligible to participate if they are proficient in English (written and spoken) and agree for at least one parent to attend

  17. Want to Teach about SuperPACs? What We Can Learn from Stephen Colbert

    ERIC Educational Resources Information Center

    Stoddard, Jeremy

    2012-01-01

    The emergence of the SuperPACs in American politics is a major issue in the current election. SuperPACs, and the media campaigns they fund, also present a major challenge for media and democratic education. This article explores the issues surrounding SuperPACs and the rise of media in elections and politics in general, and presents some starting…

  18. Frame independent cosmological perturbations

    SciTech Connect

    Prokopec, Tomislav; Weenink, Jan E-mail: j.g.weenink@uu.nl

    2013-09-01

    We compute the third order gauge invariant action for scalar-graviton interactions in the Jordan frame. We demonstrate that the gauge invariant action for scalar and tensor perturbations on one physical hypersurface only differs from that on another physical hypersurface via terms proportional to the equation of motion and boundary terms, such that the evolution of non-Gaussianity may be called unique. Moreover, we demonstrate that the gauge invariant curvature perturbation and graviton on uniform field hypersurfaces in the Jordan frame are equal to their counterparts in the Einstein frame. These frame independent perturbations are therefore particularly useful in relating results in different frames at the perturbative level. On the other hand, the field perturbation and graviton on uniform curvature hypersurfaces in the Jordan and Einstein frame are non-linearly related, as are their corresponding actions and n-point functions.

  19. NARSTO PAC2001 GVRD CAPMON AIR QUAL DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO PAC2001 GVRD CAPMON AIR QUAL DATA Project Title:  NARSTO Discipline:  ... Order:   ASDC Order Tool Parameters:  Air Temperature Humidity Upper Level Winds Ozone Aerosol Particle ... Data:  Spatial Coverage: Canada Pacific 2001 Air Quality Study SCAR-B Block:  SCAR-B ...

  20. NARSTO PAC2001 CONVAIR PM OZONE MET DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO PAC2001 CONVAIR PM OZONE MET DATA Project Title:  NARSTO Discipline:  ... Temperature Probe Humidity Probe Wind Sensor UV Ozone Detector Optical Counter Location:  Lower Fraser ... Air Temperature Humidity Upper Level Winds Ozone Aerosol Particle Properties Order Data:  ASDC Order ...

  1. NARSTO PAC2001 CESSNA VOC PM OZONE MET DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO PAC2001 CESSNA VOC PM OZONE MET DATA Project Title:  NARSTO Discipline:  ... Temperature Probe Humidity Probe Wind Sensor UV Ozone Detector Optical Counter GC Location:  Lower Fraser ... Air Temperature Humidity Upper Level Winds Ozone Aerosol Particle Properties Volatile Organic Compounds ...

  2. PACs: A Framework for Determining Appropriate Service Delivery Options.

    ERIC Educational Resources Information Center

    Blosser, Jean L.; Kratcoski, Annette

    1997-01-01

    Offers speech-language clinicians a framework for team decision making and service delivery by encouraging speech-language pathologists and their colleagues to consider the unique combination of providers, activities, and contexts (PACs) necessary to meet the specific needs of each individual with a communication disorder. Sample cases involving…

  3. Test Pac: A Program for Comprehensive Item and Reliability Analysis.

    ERIC Educational Resources Information Center

    Luecht, Richard M.

    1987-01-01

    Test Pac, a test scoring and analysis computer program for moderate-sized sample designs using dichotomous response items, performs comprehensive item analyses and multiple reliability estimates. It also performs single-facet generalizability analysis of variance, single-parameter item response theory analyses, test score reporting, and computer…

  4. HIS-RIS-modality-PACS integration in Osaka University

    NASA Astrophysics Data System (ADS)

    Kondoh, Hiroshi; Sukenobu, Yoshiharu; Mori, Yoshinobu; Nakamura, Hironobu; Kozuka, Takahiro; Inamura, Kiyonari

    1994-05-01

    The new hospital is called `Intelligent Hospital,' where HIS and RIS are installed and a part of PACS will be installed in March 1994. The aim of this system is to optimize the flow and stock of materials and information in the hospital and to provide safe and convenient circumstances for patients and hospital staffs. The preliminary study of a small PACS suggested to us that the integration of HIS, RIS and PACS increase each value of them as a total information system. In this paper we will show the software and concept of our system. (1) Integration of HIS and RIS; concerning with radiological examinations, HIS has the radiological examination order entry system and its scheduling system. The radiologist can get the patient's information at examination and reporting on the RIS terminal and input the drug and film consumption. The data transferred to HIS as billing data. The examination report is also transferred to HIS. (2) Integration of RIS and modalities; RIS sends the patient's data and examination code to FCR (Fuji. Co.) system. (3) Integration of RIS, HIS and PACS; HIS shows reference images with report on the HIS terminal.

  5. Information Management For Data Retrieval In A PACS

    NASA Astrophysics Data System (ADS)

    Prior, Fred W.; Nabijee, Kamal H.

    1989-05-01

    Data stored in a PACS archive must be organized to permit efficient retrieval. The concept of a unique data object identifier (UID) permits a fundamental partitioning of the problem into a storage system indexed by UID and a database containing descriptive elements. The database serves to map user retrieval requests, expressed in terms of clinically relevant descriptive elements, into UIDs of specific data objects. Different data organization mechanisms are employed by imaging modalities, thereby making the structure of a generic PACS database difficult. One solution may be derived by analogy from film based systems. Images and other data objects may be organized, by application of modality and site specific rules, into electronic folders. Folders, in turn may be organized into a patient master folder or user defined reference folders. Such an organization provides an easily understood user access model for information stored in PACS archives. This paper presents a PACS architecture comprising an Information Management System (IMS), and Image Storage System (ISS). Entity-Relationship diagrams are presented to define a schema for the IMS database based on the folder analogy. The folder concept and its relationship to the ACR-NEMA Standard are discussed.

  6. Millennium regional PACS management: strategies for successful implementation

    NASA Astrophysics Data System (ADS)

    Levin, Brad; Romlein, John R.; Gac, Robert J., Jr.; Chacko, Anna K.; Radvany, Martin

    2000-05-01

    With the advent of the new Millennium, Picture Archive and Communications System (PACS) technology has matured to levels sufficient to support open systems based, regional implementations. This shifts the site-centric PACS paradigm into broader scale, impacting facilities, workflow, business plans and ultimately patient care on a regional basis. Prudent and effective management of a regional implementation is critical to overall project success based upon a number of competing influences fundamental to the PACS including network infrastructure, clinical workflow, acquisition modalities, planning documentation, site preparation, acceptance testing, project communication, interface integration issues, etc. Risk mitigation is possible by understanding and managing the interrelationships of these influences through a phased approach with embedded management controls. The overall phases of regional implementation are not unlike site-centric implementations, consisting of Discovery, Planning, Preparation, Installation; Acceptance and Warranty/Maintenance; however, details which manifest over time are what provide significant management challenges. When balanced using a culturally reinforced policy of open, frequent and hands-on communication, regional PACS projects can be successfully implemented maintaining budget, schedule and scope thresholds.

  7. Operator interface design considerations for a PACS information management system

    NASA Astrophysics Data System (ADS)

    Steinke, James E.; Nabijee, Kamal H.; Freeman, Rick H.; Prior, Fred W.

    1990-08-01

    As prototype PACS grow into fully digital departmental and hospital-wide systems, effective information storage and retrieval mechanisms become increasingly important. Thus far, designers of PACS workstations have concentrated on image communication and display functionality. The new challenge is to provide appropriate operator interface environments to facilitate information retrieval. The "Marburg Model" 1 provides a detailed analysis of the functions, control flows and data structures used in Radiology. It identifies a set of "actors" who perform information manipulation functions. Drawing on this model and its associated methodology it is possible to identify four modes of use of information systems in Radiology: Clinical Routine, Research, Consultation, and Administration. Each mode has its own specific access requirements and views of information. An operator interface strategy appropriate for each mode will be proposed. Clinical Routine mode is the principal concern of PACS primary diagnosis workstations. In a full PACS implementation, such workstations must provide a simple and consistent navigational aid for the on-line image database, a local work list of cases to be reviewed, and easy access to information from other hospital information systems. A hierarchical method of information access is preferred because it provides the ability to start at high-level entities and iteratively narrow the scope of information from which to select subsequent operations. An implementation using hierarchical, nested software windows which fulfills such requirements shall be examined.

  8. Assessing The Impact Of Computed Radiography And PACS

    NASA Astrophysics Data System (ADS)

    Hedgcock, Marcus W.; Kehr, Katherine

    1989-05-01

    Our institution (San Francisco VA Medical Center) is a VA pilot center for total digital imaging and PACS. Quantitative information about PACS impact on health care is limited, because no centers have done rigorous preimplementation studies. We are gathering quantitative service delivery and cost data before, during, and after stepwise implementation of computed radiography and PACS at our institution to define the impact on imaging service delivery. We designed a simple audit method using the x-ray request and time clocks to determine patient waiting time, imaging time, film use, image availability to the radiologist, matching of current with previous images, image availability to clinicians, and time to final interpretation. Our department model is a multichannel, mulitserver patient queue. Our current radiograph file is space limited, containing only one year of images; older images are kept in a remote file area in another building. In addition, there are 16 subfile areas within the Radiology Service and the medical center. Our preimplementation audit showed some long waiting times (40 minutes, average 20) and immediate retrieval of prior films in only 42% of cases, with an average retrieval time of 22 hours. Computed radiography and the optical archive have the potential to improve these figures. The audit will be ongoing and automated as implementation of PACS progresses, to measure service improvement and learning curve with the new equipment. We present the audit format and baseline preimplementation figures.

  9. PACS implementation dramatically impacts people and radiology work processes

    NASA Astrophysics Data System (ADS)

    Ouvry, Ann

    1997-05-01

    The technology is not the bottleneck anymore in PACS implementation, it has become clear that the key to the success of PACS is understanding the current process, the end-user requirements, and how these processes will change with the introduction of PACS. We will discuss how implementation of PACS changed the working procedures in the Radiology department of Visby Hospital. Visby Hospital in Gotland, Sweden has approximately 160 beds. The Radiology department performs approximately 33,000 examinations per year and is capable of offering a broad range of diagnostic imaging services including CT and MRI. When a new facility was built in 1994, the decision was made to go for filmless operation and a modern information infrastructure. The new facility went operational by the end of 1994, in August 1995 almost filmless operation was reached. Continuing effort and attention is being paid to further simplify the workflow and working procedures in the Radiology department, and to improve the services offered to referring physicians. Although the project aimed at filmless operation, the main goal was to organize for efficient operation and excellent service, thereby maintaining high quality standards and employee satisfaction.

  10. PACS 2000: quality control using the task allocation chart

    NASA Astrophysics Data System (ADS)

    Norton, Gary S.; Romlein, John R.; Lyche, David K.; Richardson, Ronald R., Jr.

    2000-05-01

    Medical imaging's technological evolution in the next century will continue to include Picture Archive and Communication Systems (PACS) and teleradiology. It is difficult to predict radiology's future in the new millennium with both computed radiography and direct digital capture competing as the primary image acquisition methods for routine radiography. Changes in Computed Axial Tomography (CT) and Magnetic Resonance Imaging (MRI) continue to amaze the healthcare community. No matter how the acquisition, display, and archive functions change, Quality Control (QC) of the radiographic imaging chain will remain an important step in the imaging process. The Task Allocation Chart (TAC) is a tool that can be used in a medical facility's QC process to indicate the testing responsibilities of the image stakeholders and the medical informatics department. The TAC shows a grid of equipment to be serviced, tasks to be performed, and the organization assigned to perform each task. Additionally, skills, tasks, time, and references for each task can be provided. QC of the PACS must be stressed as a primary element of a PACS' implementation. The TAC can be used to clarify responsibilities during warranty and paid maintenance periods. Establishing a TAC a part of a PACS implementation has a positive affect on patient care and clinical acceptance.

  11. NARSTO PAC2001 SLOCAN PARK GAS PM MET DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO PAC2001 SLOCAN PARK GAS PM MET DATA Project Title:  NARSTO Discipline:  ... Ground Station, Tethered Balloon Instrument:  Temperature Probe Humidity Sensor Wind Sensor UV Ozone Detector Chemiliminescence TEOM GC-MS Ion Chromatograph Pressure Sensor Aethaelometer Fluorescence Spectroscopy IR CO2 ...

  12. Angular momentum evolution for galaxies

    NASA Astrophysics Data System (ADS)

    Pedrosa, S. E.; Tissera, P. B.

    2015-08-01

    Using cosmological hydrodinamics simulations we study the angular momentum content of the simulated galaxies in relation with their morphological type. We found that not only the angular momentum of the disk component follow the expected theoretical relation (Mo, Mao White model), but also the spheroidal one, with a gap due to its lost of angular momentum. We also found that the galaxy size can plot in one general relation, despite the morphological type,, in agreement with recent findings.

  13. Orbital angular momentum microlaser.

    PubMed

    Miao, Pei; Zhang, Zhifeng; Sun, Jingbo; Walasik, Wiktor; Longhi, Stefano; Litchinitser, Natalia M; Feng, Liang

    2016-07-29

    Structured light provides an additional degree of freedom for modern optics and practical applications. The effective generation of orbital angular momentum (OAM) lasing, especially at a micro- and nanoscale, could address the growing demand for information capacity. By exploiting the emerging non-Hermitian photonics design at an exceptional point, we demonstrate a microring laser producing a single-mode OAM vortex lasing with the ability to precisely define the topological charge of the OAM mode. The polarization associated with OAM lasing can be further manipulated on demand, creating a radially polarized vortex emission. Our OAM microlaser could find applications in the next generation of integrated optoelectronic devices for optical communications in both quantum and classical regimes.

  14. Orbital angular momentum microlaser

    NASA Astrophysics Data System (ADS)

    Miao, Pei; Zhang, Zhifeng; Sun, Jingbo; Walasik, Wiktor; Longhi, Stefano; Litchinitser, Natalia M.; Feng, Liang

    2016-07-01

    Structured light provides an additional degree of freedom for modern optics and practical applications. The effective generation of orbital angular momentum (OAM) lasing, especially at a micro- and nanoscale, could address the growing demand for information capacity. By exploiting the emerging non-Hermitian photonics design at an exceptional point, we demonstrate a microring laser producing a single-mode OAM vortex lasing with the ability to precisely define the topological charge of the OAM mode. The polarization associated with OAM lasing can be further manipulated on demand, creating a radially polarized vortex emission. Our OAM microlaser could find applications in the next generation of integrated optoelectronic devices for optical communications in both quantum and classical regimes.

  15. Integration of a clinical trial database with a PACS

    NASA Astrophysics Data System (ADS)

    van Herk, M.

    2014-03-01

    Many clinical trials use Electronic Case Report Forms (ECRF), e.g., from OpenClinica. Trial data is augmented if DICOM scans, dose cubes, etc. from the Picture Archiving and Communication System (PACS) are included for data mining. Unfortunately, there is as yet no structured way to collect DICOM objects in trial databases. In this paper, we obtain a tight integration of ECRF and PACS using open source software. Methods: DICOM identifiers for selected images/series/studies are stored in associated ECRF events (e.g., baseline) as follows: 1) JavaScript added to OpenClinica communicates using HTML with a gateway server inside the hospitals firewall; 2) On this gateway, an open source DICOM server runs scripts to query and select the data, returning anonymized identifiers; 3) The scripts then collects, anonymizes, zips and transmits selected data to a central trial server; 4) Here data is stored in a DICOM archive which allows authorized ECRF users to view and download the anonymous images associated with each event. Results: All integration scripts are open source. The PACS administrator configures the anonymization script and decides to use the gateway in passive (receiving) mode or in an active mode going out to the PACS to gather data. Our ECRF centric approach supports automatic data mining by iterating over the cases in the ECRF database, providing the identifiers to load images and the clinical data to correlate with image analysis results. Conclusions: Using open source software and web technology, a tight integration has been achieved between PACS and ECRF.

  16. From shared data to sharing workflow: merging PACS and teleradiology.

    PubMed

    Benjamin, Menashe; Aradi, Yinon; Shreiber, Reuven

    2010-01-01

    Due to a host of technological, interface, operational and workflow limitations, teleradiology and PACS/RIS were historically developed as separate systems serving different purposes. PACS/RIS handled local radiology storage and workflow management while teleradiology addressed remote access to images. Today advanced PACS/RIS support complete site radiology workflow for attending physicians, whether on-site or remote. In parallel, teleradiology has emerged into a service of providing remote, off-hours, coverage for emergency radiology and to a lesser extent subspecialty reading to subscribing sites and radiology groups. When attending radiologists use teleradiology for remote access to a site, they may share all relevant patient data and participate in the site's workflow like their on-site peers. The operation gets cumbersome and time consuming when these radiologists serve multi-sites, each requiring a different remote access, or when the sites do not employ the same PACS/RIS/Reporting Systems and do not share the same ownership. The least efficient operation is of teleradiology companies engaged in reading for multiple facilities. As these services typically employ non-local radiologists, they are allowed to share some of the available patient data necessary to provide an emergency report but, by enlarge, they do not share the workflow of the sites they serve. Radiology stakeholders usually prefer to have their own radiologists perform all radiology tasks including interpretation of off-hour examinations. It is possible with current technology to create a system that combines the benefits of local radiology services to multiple sites with the advantages offered by adding subspecialty and off-hours emergency services through teleradiology. Such a system increases efficiency for the radiology groups by enabling all users, regardless of location, to work "local" and fully participate in the workflow of every site. We refer to such a system as SuperPACS. PMID

  17. Inflationary tensor perturbations after BICEP2.

    PubMed

    Caligiuri, Jerod; Kosowsky, Arthur

    2014-05-16

    The measurement of B-mode polarization of the cosmic microwave background at large angular scales by the BICEP experiment suggests a stochastic gravitational wave background from early-Universe inflation with a surprisingly large amplitude. The power spectrum of these tensor perturbations can be probed both with further measurements of the microwave background polarization at smaller scales and also directly via interferometry in space. We show that sufficiently sensitive high-resolution B-mode measurements will ultimately have the ability to test the inflationary consistency relation between the amplitude and spectrum of the tensor perturbations, confirming their inflationary origin. Additionally, a precise B-mode measurement of the tensor spectrum will predict the tensor amplitude on solar system scales to 20% accuracy for an exact power-law tensor spectrum, so a direct detection will then measure the running of the tensor spectral index to high precision.

  18. Inflationary tensor perturbations after BICEP2.

    PubMed

    Caligiuri, Jerod; Kosowsky, Arthur

    2014-05-16

    The measurement of B-mode polarization of the cosmic microwave background at large angular scales by the BICEP experiment suggests a stochastic gravitational wave background from early-Universe inflation with a surprisingly large amplitude. The power spectrum of these tensor perturbations can be probed both with further measurements of the microwave background polarization at smaller scales and also directly via interferometry in space. We show that sufficiently sensitive high-resolution B-mode measurements will ultimately have the ability to test the inflationary consistency relation between the amplitude and spectrum of the tensor perturbations, confirming their inflationary origin. Additionally, a precise B-mode measurement of the tensor spectrum will predict the tensor amplitude on solar system scales to 20% accuracy for an exact power-law tensor spectrum, so a direct detection will then measure the running of the tensor spectral index to high precision. PMID:24877926

  19. Zac1 Regulates the Differentiation and Migration of Neocortical Neurons via Pac1.

    PubMed

    Adnani, Lata; Langevin, Lisa Marie; Gautier, Elodie; Dixit, Rajiv; Parsons, Kari; Li, Saiqun; Kaushik, Gaurav; Wilkinson, Grey; Wilson, Richard; Childs, Sarah; Nguyen, Minh Dang; Journot, Laurent; Dehay, Colette; Schuurmans, Carol

    2015-09-30

    Imprinted genes are dosage sensitive, and their dysregulated expression is linked to disorders of growth and proliferation, including fetal and postnatal growth restriction. Common sequelae of growth disorders include neurodevelopmental defects, some of which are indirectly related to placental insufficiency. However, several growth-associated imprinted genes are also expressed in the embryonic CNS, in which their aberrant expression may more directly affect neurodevelopment. To test whether growth-associated genes influence neural lineage progression, we focused on the maternally imprinted gene Zac1. In humans, either loss or gain of ZAC1 expression is associated with reduced growth rates and intellectual disability. To test whether increased Zac1 expression directly perturbs neurodevelopment, we misexpressed Zac1 in murine neocortical progenitors. The effects were striking: Zac1 delayed the transition of apical radial glial cells to basal intermediate neuronal progenitors and postponed their subsequent differentiation into neurons. Zac1 misexpression also blocked neuronal migration, with Zac1-overexpressing neurons pausing more frequently and forming fewer neurite branches during the period when locomoting neurons undergo dynamic morphological transitions. Similar, albeit less striking, neuronal migration and morphological defects were observed on Zac1 knockdown, indicating that Zac1 levels must be regulated precisely. Finally, Zac1 controlled neuronal migration by regulating Pac1 transcription, a receptor for the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP). Pac1 and Zac1 loss- and gain-of-function presented as phenocopies, and overexpression of Pac1 rescued the Zac1 knockdown neuronal migration phenotype. Thus, dysregulated Zac1 expression has striking consequences on neocortical development, suggesting that misexpression of this transcription factor in the brain in certain growth disorders may contribute to neurocognitive deficits

  20. Characterization of nanostructured HfO 2 films using RBS and PAC

    NASA Astrophysics Data System (ADS)

    Cavalcante, F. H. M.; Gomes, M. R.; Carbonari, A. W.; Pereira, L. F. D.; Rossetto, D. A.; Costa, M. S.; Alves, E.; Barradas, N. P.; Franco, N.; Redondo, L. M.; Lopes, A. M. L.; Soares, J. C.

    2012-02-01

    The hyperfine field at 181Ta lattice sites in a nanostructured HfO 2 thin film doped with Fe was studied using Rutherford Backscattering Spectrometry and Perturbed Angular Correlation techniques. The 409 nm Hf film was deposited by Electron Beam Evaporation on a silicon substrate. The radioactive 181Hf ions were produced by neutron activation of the nanofilm in the Brazilian Research Reactor (IPEN IEA-R1) by the reaction 180Hf(n,γ) 181Hf. These studies provided an excellent opportunity to obtain unique information regarding local arrangement of the grains, structure, phase transformations of nanoparticles and interfaces of nanostructured materials and the thin film.

  1. The Perturbed Puma Model

    NASA Astrophysics Data System (ADS)

    Rong, Shu-Jun; Liu, Qiu-Yu

    2012-04-01

    The puma model on the basis of the Lorentz and CPT violation may bring an economical interpretation to the conventional neutrinos oscillation and part of the anomalous oscillations. We study the effect of the perturbation to the puma model. In the case of the first-order perturbation which keeps the (23) interchange symmetry, the mixing matrix element Ue3 is always zero. The nonzero mixing matrix element Ue3 is obtained in the second-order perturbation that breaks the (23) interchange symmetry.

  2. Intrinsic Angular Momentum of Light.

    ERIC Educational Resources Information Center

    Santarelli, Vincent

    1979-01-01

    Derives a familiar torque-angular momentum theorem for the electromagnetic field, and includes the intrinsic torques exerted by the fields on the polarized medium. This inclusion leads to the expressions for the intrinsic angular momentum carried by the radiation traveling through a charge-free medium. (Author/MA)

  3. Effect of powdered activated carbon (PAC) and cationic polymer on biofouling mitigation in hybrid MBRs.

    PubMed

    Jamal Khan, S; Visvanathan, C; Jegatheesan, V

    2012-06-01

    In this study, the influence of powdered activated carbon (PAC) and cationic polymer (MPE50) was investigated on the fouling propensity in hybrid MBRs. Three laboratory scale MBRs were operated simultaneously including MBR(Control), MBR(PAC), and MBR(Polymer). Optimum dosages of PAC and polymer to the MBR(PAC) and MBR(Polymer), respectively were determined using jar tests. It was found that the MBR(PAC) exhibited low fouling tendency and prolonged filtration as compared to the other MBRs. Improved filtration in MBR(PAC) was attributed to the flocculation and adsorption phenomena. The effective stability of the biomass by PAC in the form of biological activated carbon (BAC) was verified by the increase in mean particle size. The BAC aided sludge layer exhibited porous cake structure resulting in the prolong filtration. However, both the membrane hybrid systems revealed effective adsorption of organic matter by 40% reduction in the soluble EPS concentration. PMID:22264429

  4. Angular signal radiography.

    PubMed

    Li, Panyun; Zhang, Kai; Bao, Yuan; Ren, Yuqi; Ju, Zaiqiang; Wang, Yan; He, Qili; Zhu, Zhongzhu; Huang, Wanxia; Yuan, Qingxi; Zhu, Peiping

    2016-03-21

    Microscopy techniques using visible photons, x-rays, neutrons, and electrons have made remarkable impact in many scientific disciplines. The microscopic data can often be expressed as the convolution of the spatial distribution of certain properties of the specimens and the inherent response function of the imaging system. The x-ray grating interferometer (XGI), which is sensitive to the deviation angle of the incoming x-rays, has attracted significant attention in the past years due to its capability in achieving x-ray phase contrast imaging with low brilliance source. However, the comprehensive and analytical theoretical framework is yet to be presented. Herein, we propose a theoretical framework termed angular signal radiography (ASR) to describe the imaging process of the XGI system in a classical, comprehensive and analytical manner. We demonstrated, by means of theoretical deduction and synchrotron based experiments, that the spatial distribution of specimens' physical properties, including absorption, refraction and scattering, can be extracted by ASR in XGI. Implementation of ASR in XGI offers advantages such as simplified phase retrieval algorithm, reduced overall radiation dose, and improved image acquisition speed. These advantages, as well as the limitations of the proposed method, are systematically investigated in this paper. PMID:27136780

  5. Investigation on structural aspects of ZnO nano-crystal using radio-active ion beam and PAC

    NASA Astrophysics Data System (ADS)

    Ganguly, Bichitra Nandi; Dutta, Sreetama; Roy, Soma; Röder, Jens; Johnston, Karl; Martin, Manfred

    2015-11-01

    Nano-crystalline ZnO has been studied with perturbed angular correlation using 111mCd, implanted at ISOLDE/CERN and X-ray diffraction using Rietveld analysis. The data show a gradual increase in the crystal size and stress for a sample annealed at 600 °C, and reaching nearly properties of standard ZnO with tempering at 1000 °C. The perturbed angular correlation data show a broad frequency distribution at low annealing temperatures and small particle sizes, whereas at high annealing temperature and larger crystal sizes, results similar to bulk ZnO have been obtained. The ZnO nano-crystalline samples were initially prepared through a wet chemical route, have been examined by Fourier Transform Infrared Spectroscopy (FT-IR) and chemical purity has been confirmed with Energy Dispersive X-ray (EDAX) analysis as well as Transmission Electron Microscopy (TEM).

  6. Fuel Fabrication for Surrogate Sphere-Pac Rodlet

    SciTech Connect

    Del Cul, G.D.

    2005-07-19

    Sphere-pac fuel consists of a blend of spheres of two or three different size fractions contained in a fuel rod. The smear density of the sphere-pac fuel column can be adjusted to the values obtained for light-water reactor (LWR) pellets (91-95%) by using three size fractions, and to values typical of the fast-reactor oxide fuel column ({approx}85%) by using two size fractions. For optimum binary packing, the diameters of the two sphere fractions must differ by at least a factor of 7 (ref. 3). Blending of spheres with smaller-diameter ratios results in difficult blending, nonuniform loading, and lower packing fractions. A mixture of about 70 vol% coarse spheres and 30 vol% fine spheres is needed to obtain high packing fractions. The limiting smear density for binary packing is 86%, with about 82% achieved in practice. Ternary packing provides greater smear densities, with theoretical values ranging from 93 to 95%. Sphere-pac technology was developed in the 1960-1990 period for thermal and fast spectrum reactors of nearly all types (U-Th and U-Pu fuel cycles, oxide and carbide fuels), but development of this technology was most strongly motivated by the need for remote fabrication in the thorium fuel cycle. The application to LWR fuels as part of the DOE Fuel Performance Improvement Program did not result in commercial deployment for a number of reasons, but the relatively low production cost of existing UO{sub 2} pellet fuel is probably the most important factor. In the case of transmutation fuels, however, sphere-pac technology has the potential to be a lower-cost alternative while also offering great flexibility in tailoring the fuel elements to match the exact requirements of any particular reactor core at any given time in the cycle. In fact, the blend of spheres can be adjusted to offer a different composition for each fuel pin or group of pins in a given fuel element. Moreover, it can even provide a vertical gradient of composition in a single fuel pin. For

  7. Development of PACS Digital Pump and implications for other industries

    NASA Astrophysics Data System (ADS)

    Banister, M.; Vohnout, S.; Kenman, D.

    2007-04-01

    This paper discusses the development and system integration of the Pulse Activated Cell System (PACS) Digital Pump technology using 2 types of electro-activated polymer (EAP) actuators. This is a platform specifically developed for the integration of sensor feedback loops to create an autonomous fluidic monitoring, reaction and delivery system. Initial, proof of concept, performance testing results are discussed as well as development for a medical drug delivery device and higher volume infusion therapy device. Uses and applications of the technology in other industries is considered as the PAC System provides a new ability to pump single or multiple fluid flows in a single pump that is programmable with the ability to vary direction, pressure and flow rates. The result is digital control of fluidic delivery, testing and mixing in application scaleable product packages. This technology will lead to new low cost yet sophisticated fluidic processing products and devices for many industries.

  8. PACS workstation for computer-assisted image diagnosis

    NASA Astrophysics Data System (ADS)

    Hosoba, Minoru; Horino, Masato; Takemura, Kunihiko; Wani, Hidenobu; Hidaka, Akinari; Hatabu, Hiroto; Kasagi, Kanji; Konishi, Junji

    1990-08-01

    Major two functions that a PACS workstation is considered to be equipped with are 1) efficient retrieval of image data and 2) supporting or consultation of writing reports, as radiologists have to diagnose increasing number of digital images in routine clinical studies. The authors developed a prototype PACS workstation with high speed image retrieving architecture and computer aided diagnosis and reporting function by using an artificial intelligence technology (AIPACS workstation). When physician selects the patient and his studies, the system performs feature extraction and generates diagnostic report by the inference engine with backward reasoning using the knowledge installed as production rules. Clinical application to the system for thyroid diagnosis showed good correlation with the diagnosis done by the physician.

  9. Protecting clinical data in PACS, teleradiology systems, and research environments

    NASA Astrophysics Data System (ADS)

    Meissner, Marion C.; Collmann, Jeff R.; Tohme, Walid G.; Mun, Seong K.

    1997-05-01

    As clinical data is more widely stored in electronic patient record management systems and transmitted over the Internet and telephone lines, it becomes more accessible and therefore more useful, but also more vulnerable. Computer systems such as PACS, telemedicine applications, and medical research networks must protect against accidental or deliberate modification, disclosure, and violation of patient confidentiality in order to be viable. Conventional wisdom in the medical field and among lawmakers legislating the use of electronic medical records suggests that, although it may improve access to information, an electronic medical record cannot be as secure as a traditional paper record. This is not the case. Information security is a well-developed field in the computer and communications industry. If medical information systems, such as PACS, telemedicine applications, and research networks, properly apply information security techniques, they can ensure the accuracy and confidentiality of their patient information and even improve the security of their data over a traditional paper record. This paper will elaborate on some of these techniques and discuss how they can be applied to medical information systems. The following systems will be used as examples for the analysis: a research laboratory at Georgetown University Medical Center, the Deployable Radiology system installed to support the US Army's peace- keeping operation in Bosnia, a kidney dialysis telemedicine system in Washington, D.C., and various experiences with implementing and integrating PACS.

  10. Pac-man motility of kinetochores unleashed by laser microsurgery

    PubMed Central

    LaFountain, James R.; Cohan, Christopher S.; Oldenbourg, Rudolf

    2012-01-01

    We report on experiments directly in living cells that reveal the regulation of kinetochore function by tension. X and Y sex chromosomes in crane fly (Nephrotoma suturalis) spermatocytes exhibit an atypical segregation mechanism in which each univalent maintains K-fibers to both poles. During anaphase, each maintains a leading fiber (which shortens) to one pole and a trailing fiber (which elongates) to the other. We used this intriguing behavior to study the motile states that X-Y kinetochores are able to support during anaphase. We used a laser microbeam to either sever a univalent along the plane of sister chromatid cohesion or knock out one of a univalent's two kinetochores to release one or both from the resistive influence of its sister's K-fiber. Released kinetochores with attached chromosome arms moved poleward at rates at least two times faster than normal. Furthermore, fluorescent speckle microscopy revealed that detached kinetochores converted their functional state from reverse pac-man to pac-man motility as a consequence of their release from mechanical tension. We conclude that kinetochores can exhibit pac-man motility, even though their normal behavior is dominated by traction fiber mechanics. Unleashing of kinetochore motility through loss of resistive force is further evidence for the emerging model that kinetochores are subject to tension-sensitive regulation. PMID:22740625

  11. Hospital-integrated PACS at the University Hospital of Geneva

    NASA Astrophysics Data System (ADS)

    Ratib, Osman M.; Ligier, Yves; Hochstrasser, Denis; Scherrer, Jean-Raoul

    1991-07-01

    The PACS under development at the University Hospital of Geneva is a hospital-wide image management system for radiological as well as non-radiological medical images which is part of one of the widest hospital information systems (HIS) in Switzerland (Diogene system). It is based on a multi-vendor open architecture and a set of widely available industry standards, namely: Unix as the operating system, TCP-IP as network protocol and an SQL-based distributed database (INGRES) that handles both the PACS and the HIS. The PACS is based on a distributed architecture of servers of two types: the archive servers connected to the sources of images and equipped with large optical disk libraries (jukeboxes) and display servers distributed over the hospital. A standard image storage format was developed based on the ACR-NEMA standard. This file format (the PAPYRUS format) allows storage of sets of images as a sequence of ACR-NEMA messages in an 'encapsulated' file structure. In order to provide a more uniform user interface on a variety of different workstations, a common platform for image display and manipulation called OSIRIS is developed based on X-11 windowing system and OSF/Motif extension. Such a platform is designed to be portable to any computer running Unix and equipped with a graphic display system running X-11. Because this software is written in the object-oriented language C++, it is easily expandable and easily adaptable to different needs and requirements.

  12. Toshiba General Hospital PACS for routine in- and outpatient clinics

    NASA Astrophysics Data System (ADS)

    Toshimitsu, Akihiro; Okazaki, Nobuo; Kura, Hiroyuki; Nishihara, Eitaro; Tsubura, Shinichi

    1996-05-01

    The Toshiba General Hospital introduced a departmental RIS/PACS (Radiology Information System/Picture Archiving and Communication System) in the radiology department in May, 1993. It has been used routinely since that time. In order to provide efficient means for clinicians to find and read many images, the system has been expanded to the neurosurgery and urology clinics and wards since May, 1995, and five image referring workstations now provide digital images to clinicians. In this paper we discuss an algorithm for image migration, one of the key issues to accomplish the expansion to outpatient clinics successfully, and propose the WYWIWYG (what you want is what you get) image transfer logic. This is the logic used to transfer images that physicians require refer without increasing the traffic between the image server and referring workstations. We accomplish the WYWIWYG logic by prioritizing exams the physicians have not yet viewed and by finding historical exams according to the modality, anatomy, and marking. Clinicians gave us comments from their first use of the system and suggested that the PACS enables clinicians to review images more efficiently compared to a film-based system. Our experience suggests that it is a key to the effective application of PACS in outpatient clinics to incorporate consideration patterns of clinicians on the migration algorithm.

  13. Regional maintenance approach for PACS within the healthcare enterprise

    NASA Astrophysics Data System (ADS)

    Staley, Steven D.; Romlein, John R.; Chacko, Anna K.; Radvany, Martin

    2000-05-01

    With the proliferation of Picture Archiving and Communications Systems (PACS) throughout the U.S. Healthcare System, there is an immense need for alternative approaches to maintenance support of PACS systems. One method of cost reduction is through the implementation of regional maintenance programs. While many PACS vendors are willing to negotiate various forms of shared service arrangements, multi-facility and regional negotiations are rarely implemented. This paper will present such an approach by describing a four step process: (1) Identify maintenance tasks across the entire region/enterprise; (2) Identify maintenance resources within the region/enterprise that can be assigned against those tasks; (3) Identify vendor unique resources that must be added to regional/enterprise resources to complete the required coverage of maintenance tasks; and (4) Negotiate with all member sites of the region/enterprise and the vendor for the assignment of resources against all maintenance tasks. Additionally, these steps will be balanced through identification of the principal tradeoffs tied to maintenance resourcing, namely: quality, speed and cost. If this approach is implemented, it presents a mechanism for achieving maintenance service cost reductions, while supporting clinical operations, through the benefits of economies of scale and collective bargaining.

  14. A RIS/PACS simulator with web-based image distribution and display system for education

    NASA Astrophysics Data System (ADS)

    Zhou, Zheng; Huang, H. K.; Liu, Brent J.; Cao, Fei; Zhang, Jianguo; Mogel, Greg; Law, Maria Y. Y.

    2004-04-01

    As PACS and related imaging technologies become more common in the healthcare setting, better methods are needed for training radiologists, allied healthcare and IT providers to understand and use them effectively. We presented a PACS Simulator in 2002 and a RIS integrated PACS Simulator in 2003. In this presentation we integrate a web-based image distribution and display system with the Simulator to complete the simulation of clinical PACS workflow. The Simulator consists of RIS Simulator, modality Simulator, DICOM gateway, PACS controller, clinical viewing workstations, PACS monitor system and a web server. The addition web server distributes images to browser-based display clients for display and manipulation using web technology. Using this Simulator, trainees can: (1) Observe RIS/PACS operation with web image distribution, component by component, (2) Trace image data flow through each component, (3) Query, retrieve and review images at web display clients, (4) Induce failure in a component to observe its impact on the entire RIS/PACS operation. The Simulator has been developed as a stand-alone tool for trainees to understand RIS/PACS concept and appreciate RIS/PACS workflow with hands-on experience. The Simulator has been applied in many training classes, and the addition of web server will significantly improve its training value.

  15. Perturbations for transient acceleration

    SciTech Connect

    Vargas, Cristofher Zuñiga; Zimdahl, Winfried; Hipólito-Ricaldi, Wiliam S. E-mail: hipolito@ceunes.ufes.br

    2012-04-01

    According to the standard ΛCDM model, the accelerated expansion of the Universe will go on forever. Motivated by recent observational results, we explore the possibility of a finite phase of acceleration which asymptotically approaches another period of decelerated expansion. Extending an earlier study on a corresponding homogeneous and isotropic dynamics, in which interactions between dark matter and dark energy are crucial, the present paper also investigates the dynamics of the matter perturbations both on the Newtonian and General Relativistic (GR) levels and quantifies the potential relevance of perturbations of the dark-energy component. In the background, the model is tested against the Supernova type Ia (SNIa) data of the Constitution set and on the perturbative level against growth rate data, among them those of the WiggleZ survey, and the data of the 2dFGRS project. Our results indicate that a transient phase of accelerated expansion is not excluded by current observations.

  16. Vortex perturbation dynamics

    NASA Technical Reports Server (NTRS)

    Criminale, W. O.; Lasseigne, D. G.; Jackson, T. L.

    1995-01-01

    An initial value approach is used to examine the dynamics of perturbations introduced into a vortex under strain. Both the basic vortex considered and the perturbations are taken as fully three-dimensional. An explicit solution for the time evolution of the vorticity perturbations is given for arbitrary initial vorticity. Analytical solutions for the resulting velocity components are found when the initial vorticity is assumed to be localized. For more general initial vorticity distributions, the velocity components are determined numerically. It is found that the variation in the radial direction of the initial vorticity disturbance is the most important factor influencing the qualitative behavior of the solutions. Transient growth in the magnitude of the velocity components is found to be directly attributable to the compactness of the initial vorticity.

  17. Transverse angular momentum of photons

    SciTech Connect

    Aiello, Andrea

    2010-05-15

    We develop the quantum theory of transverse angular momentum of light beams. The theory applies to paraxial and quasiparaxial photon beams in vacuum and reproduces the known results for classical beams when applied to coherent states of the field. Both the Poynting vector, alias the linear momentum, and the angular-momentum quantum operators of a light beam are calculated including contributions from first-order transverse derivatives. This permits a correct description of the energy flow in the beam and the natural emergence of both the spin and the angular momentum of the photons. We show that for collimated beams of light, orbital angular-momentum operators do not satisfy the standard commutation rules. Finally, we discuss the application of our theory to some concrete cases.

  18. Total angular momentum waves for scalar, vector, and tensor fields

    NASA Astrophysics Data System (ADS)

    Dai, Liang; Kamionkowski, Marc; Jeong, Donghui

    2012-12-01

    Most calculations in cosmological perturbation theory, including those dealing with the inflationary generation of perturbations, their time evolution, and their observational consequences, decompose those perturbations into plane waves (Fourier modes). However, for some calculations, particularly those involving observations performed on a spherical sky, a decomposition into waves of fixed total angular momentum (TAM) may be more appropriate. Here we introduce TAM waves—solutions of fixed total angular momentum to the Helmholtz equation—for three-dimensional scalar, vector, and tensor fields. The vector TAM waves of given total angular momentum can be decomposed further into a set of three basis functions of fixed orbital angular momentum, a set of fixed helicity, or a basis consisting of a longitudinal (L) and two transverse (E and B) TAM waves. The symmetric traceless rank-2 tensor TAM waves can be similarly decomposed into a basis of fixed orbital angular momentum or fixed helicity, or a basis that consists of a longitudinal (L), two vector (VE and VB, of opposite parity), and two tensor (TE and TB, of opposite parity) waves. We show how all of the vector and tensor TAM waves can be obtained by applying derivative operators to scalar TAM waves. This operator approach then allows one to decompose a vector field into three covariant scalar fields for the L, E, and B components and symmetric-traceless-tensor fields into five covariant scalar fields for the L, VE, VB, TE, and TB components. We provide projections of the vector and tensor TAM waves onto vector and tensor spherical harmonics. We provide calculational detail to facilitate the assimilation of this formalism into cosmological calculations. As an example, we calculate the power spectra of the deflection angle for gravitational lensing by density perturbations and by gravitational waves. We comment on an alternative approach to cosmic microwave background fluctuations based on TAM waves. An

  19. Even perturbations of the self-similar Vaidya space-time

    SciTech Connect

    Nolan, Brien C.; Waters, Thomas J.

    2005-05-15

    We study even parity metric and matter perturbations of all angular modes in self-similar Vaidya space-time. We focus on the case where the background contains a naked singularity. Initial conditions are imposed, describing a finite perturbation emerging from the portion of flat space-time preceding the matter-filled region of space-time. The most general perturbation satisfying the initial conditions is allowed to impinge upon the Cauchy horizon (CH), where the perturbation remains finite: There is no 'blue-sheet' instability. However, when the perturbation evolves through the CH and onto the second future similarity horizon of the naked singularity, divergence necessarily occurs: This surface is found to be unstable. The analysis is based on the study of individual modes following a Mellin transform of the perturbation. We present an argument that the full perturbation remains finite after resummation of the (possibly infinite number of) modes.

  20. A WEB-based telePACS using an asymmetric satellite system.

    PubMed

    Hwang, S C; Lee, M H

    2000-09-01

    We have developed a WWW-based TelePACS that can access every permitted PACS server via the Internet. Java programming techniques were used to implement the system, which can access and retrieve medical information and images through Web browsers only such as Netscape without specific tools. We also have developed a consolidator that performs as a manager to connect a conventional PACS server to a Web-based TelePACS server. We have developed the Asymmetric Satellite Data Communication System (ASDCS) as a fast communication system. The ASDCS uses a receive-only satellite link for data delivery and a terrestrial network for control communication. In conclusion, we were able to develop a cost-effective and fast PACS using Web technology. Web technology expanded the scope of use for a dedicated PACS from intrahospital to public use. PMID:11026591

  1. Treatment of coal gasification wastewater by membrane bioreactor hybrid powdered activated carbon (MBR–PAC) system.

    PubMed

    Jia, Shengyong; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng; Fang, Fang; Zhao, Qian

    2014-12-01

    A laboratory-scale membrane bioreactor hybrid powdered activated carbon (MBR–PAC) system was developed to treat coal gasification wastewater to enhance the COD, total phenols (TPh), NH4+ removals and migrate the membrane fouling. Since the MBR–PAC system operated with PAC dosage of 4 g L−1, the maximum removal efficiencies of COD, TPh and NH4+ reached 93%, 99% and 63%, respectively with the corresponding influent concentrations of 2.27 g L−1, 497 mg L−1 and 164 mg N L−1; the PAC extraction efficiencies of COD, TPh and NH4+ were 6%, 3% and 13%, respectively; the transmembrane pressure decreased 34% with PAC after 50 d operation. The results demonstrate that PAC played a key role in the enhancement of biodegradability and mitigation of membrane fouling. PMID:25461944

  2. Cosmological perturbations in antigravity

    NASA Astrophysics Data System (ADS)

    Oltean, Marius; Brandenberger, Robert

    2014-10-01

    We compute the evolution of cosmological perturbations in a recently proposed Weyl-symmetric theory of two scalar fields with oppositely signed conformal couplings to Einstein gravity. It is motivated from the minimal conformal extension of the standard model, such that one of these scalar fields is the Higgs while the other is a new particle, the dilaton, introduced to make the Higgs mass conformally symmetric. At the background level, the theory admits novel geodesically complete cyclic cosmological solutions characterized by a brief period of repulsive gravity, or "antigravity," during each successive transition from a big crunch to a big bang. For simplicity, we consider scalar perturbations in the absence of anisotropies, with potential set to zero and without any radiation. We show that despite the necessarily wrong-signed kinetic term of the dilaton in the full action, these perturbations are neither ghostlike nor tachyonic in the limit of strongly repulsive gravity. On this basis, we argue—pending a future analysis of vector and tensor perturbations—that, with respect to perturbative stability, the cosmological solutions of this theory are viable.

  3. Scalar cosmological perturbations

    NASA Astrophysics Data System (ADS)

    Uggla, Claes; Wainwright, John

    2012-05-01

    Scalar perturbations of Friedmann-Lemaitre cosmologies can be analyzed in a variety of ways using Einstein’s field equations, the Ricci and Bianchi identities, or the conservation equations for the stress-energy tensor, and possibly introducing a timelike reference congruence. The common ground is the use of gauge invariants derived from the metric tensor, the stress-energy tensor, or from vectors associated with a reference congruence, as basic variables. Although there is a complication in that there is no unique choice of gauge invariants, we will show that this can be used to advantage. With this in mind our first goal is to present an efficient way of constructing dimensionless gauge invariants associated with the tensors that are involved, and of determining their inter-relationships. Our second goal is to give a unified treatment of the various ways of writing the governing equations in dimensionless form using gauge-invariant variables, showing how simplicity can be achieved by a suitable choice of variables and normalization factors. Our third goal is to elucidate the connection between the metric-based approach and the so-called 1 + 3 gauge-invariant approach to cosmological perturbations. We restrict our considerations to linear perturbations, but our intent is to set the stage for the extension to second-order perturbations.

  4. Cosmic microwave background bispectrum on small angular scales

    SciTech Connect

    Pitrou, Cyril; Uzan, Jean-Philippe; Bernardeau, Francis

    2008-09-15

    This article investigates the nonlinear evolution of cosmological perturbations on sub-Hubble scales in order to evaluate the unavoidable deviations from Gaussianity that arise from the nonlinear dynamics. It shows that the dominant contribution to modes coupling in the cosmic microwave background temperature anisotropies on small angular scales is driven by the sub-Hubble nonlinear evolution of the dark matter component. The perturbation equations, involving, in particular, the first moments of the Boltzmann equation for photons, are integrated up to second order in perturbations. An analytical analysis of the solutions gives a physical understanding of the result as well as an estimation of its order of magnitude. This allows one to quantify the expected deviation from Gaussianity of the cosmic microwave background temperature anisotropy and, in particular, to compute its bispectrum on small angular scales. Restricting to equilateral configurations, we show that the nonlinear evolution accounts for a contribution that would be equivalent to a constant primordial non-Gaussianity of order f{sub NL}{approx}25 on scales ranging approximately from l{approx}1000 to l{approx}3000.

  5. Parallel Synthesis and Biological Evaluation of 837 Analogues of Procaspase-Activating Compound 1 (PAC-1)

    PubMed Central

    Hsu, Danny C.; Roth, Howard S.; West, Diana C.; Botham, Rachel C.; Novotny, Chris J.; Schmid, Steven C.; Hergenrother, Paul J.

    2011-01-01

    Procaspase-Activating Compound 1 (PAC-1) is an ortho-hydroxy N-acyl hydrazone that enhances the enzymatic activity of procaspase-3 in vitro and induces apoptosis in cancer cells. An analogue of PAC-1, called S-PAC-1, was evaluated in a veterinary clinical trial in pet dogs with lymphoma and found to have considerable potential as an anticancer agent. With the goal of identifying more potent compounds in this promising class of experimental therapeutics, a combinatorial library based on PAC-1 was created, and the compounds were evaluated for their ability to induce death of cancer cells in culture. For library construction, 31 hydrazides were condensed in parallel with 27 aldehydes to create 837 PAC-1 analogues, with an average purity of 91%. The compounds were evaluated for their ability to induce apoptosis in cancer cells, and through this work, six compounds were discovered to be substantially more potent than PAC-1 and S-PAC-1. These six hits were further evaluated for their ability to relieve zinc-mediated inhibition of procaspase-3 in vitro. In general, the newly identified hit compounds are two- to four-fold more potent than PAC-1 and S-PAC-1 in cell culture, and thus have promise as experimental therapeutics for treatment of the many cancers that have elevated expression levels of procaspase-3. PMID:22007686

  6. Educational RIS/PACS simulator integrated with the HIPAA compliant auditing (HCA) toolkit

    NASA Astrophysics Data System (ADS)

    Zhou, Zheng; Liu, Brent J.; Huang, H. K.; Zhang, J.

    2005-04-01

    Health Insurance Portability and Accountability Act (HIPAA), a guideline for healthcare privacy and security, has been officially instituted recently. HIPAA mandates healthcare providers to follow its privacy and security rules, one of which is to have the ability to generate audit trails on the data access for any specific patient on demand. Although most current medical imaging systems such as PACS utilize logs to record their activities, there is a lack of formal methodology to interpret these large volumes of log data and generate HIPAA compliant auditing trails. In this paper, we present a HIPAA compliant auditing (HCA) toolkit for auditing the image data flow of PACS. The toolkit can extract pertinent auditing information from the logs of various PACS components and store the information in a centralized auditing database. The HIPAA compliant audit trails can be generated based on the database, which can also be utilized for data analysis to facilitate the dynamic monitoring of the data flow of PACS. In order to demonstrate the HCA toolkit in a PACS environment, it was integrated with the PACS Simulator, that was presented as an educational tool in 2003 and 2004 SPIE. With the integration of the HCA toolkit with the PACS simulator, users can learn HIPAA audit concepts and how to generate audit trails of image data access in PACS, as well as trace the image data flow of PACS Simulator through the toolkit.

  7. Liouvillian perturbations of black holes

    NASA Astrophysics Data System (ADS)

    Couch, W. E.; Holder, C. L.

    2007-10-01

    We apply the well-known Kovacic algorithm to find closed form, i.e., Liouvillian solutions, to the differential equations governing perturbations of black holes. Our analysis includes the full gravitational perturbations of Schwarzschild and Kerr, the full gravitational and electromagnetic perturbations of Reissner-Nordstrom, and specialized perturbations of the Kerr-Newman geometry. We also include the extreme geometries. We find all frequencies ω, in terms of black hole parameters and an integer n, which allow Liouvillian perturbations. We display many classes of black hole parameter values and their corresponding Liouvillian perturbations, including new closed-form perturbations of Kerr and Reissner-Nordstrom. We also prove that the only type 1 Liouvillian perturbations of Schwarzschild are the known algebraically special ones and that type 2 Liouvillian solutions do not exist for extreme geometries. In cases where we do not prove the existence or nonexistence of Liouvillian perturbations we obtain sequences of Diophantine equations on which decidability rests.

  8. A new approach to the propagation of light-like signals in perturbed cosmological backgrounds

    SciTech Connect

    Fanizza, G.; Gasperini, M.; Marozzi, G.; Veneziano, G. E-mail: gasperini@ba.infn.it E-mail: Gabriele.Veneziano@cern.ch

    2015-08-01

    We present a new method to compute the deflection of light rays in a perturbed FLRW geometry. We exploit the properties of the Geodesic Light Cone (GLC) gauge where null rays propagate at constant angular coordinates irrespectively of the given (inhomogeneous and/or anisotropic) geometry. The gravitational deflection of null geodesics can then be obtained, in any other gauge, simply by expressing the angular coordinates of the given gauge in terms of the GLC angular coordinates. We apply this method to the standard Poisson gauge, including scalar perturbations, and give the full result for the deflection effect in terms of the direction of observation and observed redshift up to second order, and up to third order for the leading lensing terms. We also compare our results with those presently available in the literature and, in particular, we provide a new non trivial check of a previous result on the luminosity-redshift relation up to second order in cosmological perturbation theory.

  9. Pacific Tracker 2 - expert system (PacTrac2-ES) behavioural assessment and intervention tool for the Pacific Kids DASH for Health (PacDASH) study.

    PubMed

    Novotny, Rachel; Nigg, Claudio; McGlone, Katalina; Renda, Gloria; Jung, Noah; Matsunaga, Masako; Karanja, Njeri

    2013-10-01

    The Pacific Tracker (PacTrac) is a computer program designed to analyse food intakes of individuals from the Pacific Region. PacTrac's original output included servings of daily intake of food groups according to the United States Food Guide Pyramid, nutrient intake recommendations, and a comparison to other national nutrition recommendations. PacTrac was made available for public use through the Hawaii Foods website (hawaiifoods.hawaii.edu). PacTrac2 is an updated and expanded version of PacTrac that uses the United States MyPyramid/MyPlate food groups in household units of daily intake, rather than servings. In addition, the PacTrac2 includes a physical activity analysis tool which quantifies minutes of physical activities and their intensities based on energy estimates from the compendium of physical activity and research on children. An Expert System (ES) - a computerised decision tree to guide behaviour change - was developed using information on self-efficacy and stage of readiness to change, and the fruit and vegetable intake and physical activity information from PacTrac2. The ES produces reports for the child, the parent/guardian, and the child's physician with child-specific strategies, targeted behavioural information, and feedback tailored to the child. PacTrac2-ES was designed for the Pacific Kids DASH for Health (PacDASH) intervention study, conducted in the Kaiser Permanente health care system in Hawaii. The intervention is based on the child's self-efficacy and stage of readiness to change intake of fruits and vegetables and physical activity, with a goal of maintaining body weight to prevent obesity. The intervention is complemented with stage-based mailers addressing the environment for physical activity and fruit and vegetable intake and newsletters that address related behaviours (sedentary activity and a DASH eating approach). This project is the first to expand the PacTrac to contain children's foods and physical activities from the Pacific

  10. Pacific Tracker 2 - expert system (PacTrac2-ES) behavioural assessment and intervention tool for the Pacific Kids DASH for Health (PacDASH) study.

    PubMed

    Novotny, Rachel; Nigg, Claudio; McGlone, Katalina; Renda, Gloria; Jung, Noah; Matsunaga, Masako; Karanja, Njeri

    2013-10-01

    The Pacific Tracker (PacTrac) is a computer program designed to analyse food intakes of individuals from the Pacific Region. PacTrac's original output included servings of daily intake of food groups according to the United States Food Guide Pyramid, nutrient intake recommendations, and a comparison to other national nutrition recommendations. PacTrac was made available for public use through the Hawaii Foods website (hawaiifoods.hawaii.edu). PacTrac2 is an updated and expanded version of PacTrac that uses the United States MyPyramid/MyPlate food groups in household units of daily intake, rather than servings. In addition, the PacTrac2 includes a physical activity analysis tool which quantifies minutes of physical activities and their intensities based on energy estimates from the compendium of physical activity and research on children. An Expert System (ES) - a computerised decision tree to guide behaviour change - was developed using information on self-efficacy and stage of readiness to change, and the fruit and vegetable intake and physical activity information from PacTrac2. The ES produces reports for the child, the parent/guardian, and the child's physician with child-specific strategies, targeted behavioural information, and feedback tailored to the child. PacTrac2-ES was designed for the Pacific Kids DASH for Health (PacDASH) intervention study, conducted in the Kaiser Permanente health care system in Hawaii. The intervention is based on the child's self-efficacy and stage of readiness to change intake of fruits and vegetables and physical activity, with a goal of maintaining body weight to prevent obesity. The intervention is complemented with stage-based mailers addressing the environment for physical activity and fruit and vegetable intake and newsletters that address related behaviours (sedentary activity and a DASH eating approach). This project is the first to expand the PacTrac to contain children's foods and physical activities from the Pacific

  11. PAC learning algorithms for functions approximated by feedforward networks

    SciTech Connect

    Rao, N.S.V.; Protopopescu, V.

    1996-06-01

    The authors present a class of efficient algorithms for PAC learning continuous functions and regressions that are approximated by feedforward networks. The algorithms are applicable to networks with unknown weights located only in the output layer and are obtained by utilizing the potential function methods of Aizerman et al. Conditions relating the sample sizes to the error bounds are derived using martingale-type inequalities. For concreteness, the discussion is presented in terms of neural networks, but the results are applicable to general feedforward networks, in particular to wavelet networks. The algorithms can be directly adapted to concept learning problems.

  12. Information Flow Analysis As A Tool For Pacs Development

    NASA Astrophysics Data System (ADS)

    Rogers, D. C.; Wallace, R.; Thompson, B. G...; Parrish, D. M.

    1986-06-01

    Multiple benefits for PACS development can be expected to derive from careful assessment or modeling of current system operations. Our approach to modeling the radiology department operations at UNC-CH is based on two assumptions: 1) a department consists of multiple, operationally similar modules and 2) individual modules can be sufficiently characterized by use of a single template. Our procedures and conclusions in developing the modality portion of this template are described. Future modeling work is directed towards characterizing interactions within radiology and between radiology and other clinics which should, we believe, complete the characterization for a single module of the radiology department.

  13. Angular Eigenvalues of Higher-Dimensional KERR-(A)dS Black Holes with Two Rotations

    NASA Astrophysics Data System (ADS)

    Cho, H. T.; Cornell, A. S.; Doukas, Jason; Naylor, Wade

    In this paper, following the work of Chen, Lü and Pope, we present the general metric for Kerr-(A)dS black holes with two rotations. The corresponding Klein-Gordon equation is separated explicitly, from which we develop perturbative expansions for the angular eigenvalues in powers of the rotation parameters with D ≥ 6.

  14. Resilience of hybrid optical angular momentum qubits to turbulence.

    PubMed

    Farías, Osvaldo Jiménez; D'Ambrosio, Vincenzo; Taballione, Caterina; Bisesto, Fabrizio; Slussarenko, Sergei; Aolita, Leandro; Marrucci, Lorenzo; Walborn, Stephen P; Sciarrino, Fabio

    2015-02-12

    Recent schemes to encode quantum information into the total angular momentum of light, defining rotation-invariant hybrid qubits composed of the polarization and orbital angular momentum degrees of freedom, present interesting applications for quantum information technology. However, there remains the question as to how detrimental effects such as random spatial perturbations affect these encodings. Here, we demonstrate that alignment-free quantum communication through a turbulent channel based on hybrid qubits can be achieved with unit transmission fidelity. In our experiment, alignment-free qubits are produced with q-plates and sent through a homemade turbulence chamber. The decoding procedure, also realized with q-plates, relies on both degrees of freedom and renders an intrinsic error-filtering mechanism that maps errors into losses.

  15. Angular Power Spectrum in Modular Invariant Inflation Model

    SciTech Connect

    Hayashi, Mitsuo J.; Okame, Y.; Takagi, K.; Watanabe, T.; Hirai, S.; Takami, T.

    2008-05-29

    A scalar potential of inflation is proposed and the angular power spectra of the adiabatic density perturbations are computed. The potential consists of three scalar fields, S, Y and T, together with two free parameters. By fitting the parameters to cosmological data at the fixed point T = 1, we find that the potential behaves like the single-field potential of S, which slowly rolls down. We further show that the inflation predictions corresponding to this potential provide a good fit to the recent three-year WMAP data, e.g. the spectral index n{sub s} = 0.951.The TT and TE angular power spectra obtained from our model almost completely coincide with the corresponding results obtained from the {lambda}CDM model. We conclude that our model is considered to be an adequate theory of inflation that explains the present data.

  16. Resilience of hybrid optical angular momentum qubits to turbulence

    PubMed Central

    Farías, Osvaldo Jiménez; D'Ambrosio, Vincenzo; Taballione, Caterina; Bisesto, Fabrizio; Slussarenko, Sergei; Aolita, Leandro; Marrucci, Lorenzo; Walborn, Stephen P.; Sciarrino, Fabio

    2015-01-01

    Recent schemes to encode quantum information into the total angular momentum of light, defining rotation-invariant hybrid qubits composed of the polarization and orbital angular momentum degrees of freedom, present interesting applications for quantum information technology. However, there remains the question as to how detrimental effects such as random spatial perturbations affect these encodings. Here, we demonstrate that alignment-free quantum communication through a turbulent channel based on hybrid qubits can be achieved with unit transmission fidelity. In our experiment, alignment-free qubits are produced with q-plates and sent through a homemade turbulence chamber. The decoding procedure, also realized with q-plates, relies on both degrees of freedom and renders an intrinsic error-filtering mechanism that maps errors into losses. PMID:25672667

  17. Aspects of perturbative unitarity

    NASA Astrophysics Data System (ADS)

    Anselmi, Damiano

    2016-07-01

    We reconsider perturbative unitarity in quantum field theory and upgrade several arguments and results. The minimum assumptions that lead to the largest time equation, the cutting equations and the unitarity equation are identified. Using this knowledge and a special gauge, we give a new, simpler proof of perturbative unitarity in gauge theories and generalize it to quantum gravity, in four and higher dimensions. The special gauge interpolates between the Feynman gauge and the Coulomb gauge without double poles. When the Coulomb limit is approached, the unphysical particles drop out of the cuts and the cutting equations are consistently projected onto the physical subspace. The proof does not extend to nonlocal quantum field theories of gauge fields and gravity, whose unitarity remains uncertain.

  18. Degenerate density perturbation theory

    NASA Astrophysics Data System (ADS)

    Palenik, Mark C.; Dunlap, Brett I.

    2016-09-01

    Fractional occupation numbers can be used in density functional theory to create a symmetric Kohn-Sham potential, resulting in orbitals with degenerate eigenvalues. We develop the corresponding perturbation theory and apply it to a system of Nd degenerate electrons in a harmonic oscillator potential. The order-by-order expansions of both the fractional occupation numbers and unitary transformations within the degenerate subspace are determined by the requirement that a differentiable map exists connecting the initial and perturbed states. Using the X α exchange-correlation (XC) functional, we find an analytic solution for the first-order density and first- through third-order energies as a function of α , with and without a self-interaction correction. The fact that the XC Hessian is not positive definite plays an important role in the behavior of the occupation numbers.

  19. Phenomenology of preequilibrium angular distributions

    SciTech Connect

    Kalbach, C.; Mann, F.M.

    1980-05-01

    The systematics of continuum angular distributions from a wide variety of light ion nuclear reactions have been studied. To first order, the shape of the angular distributions have been found to depend only on the energy of the outgoing particle and on the division of the cross section into multi-step direct and multi-step compound parts. The angular distributions can be described in terms of Legendre polynomials with the reduced polynomial coefficients exhibiting a simple dependence on the outgoing particle energy. Two integer and four continuous parameters with universal values are needed to describe the coefficients for outgoing energies of 2 to 60 MeV in all the reaction types studied. This parameterization combined with a modified Griffin model computer code permits the calculation of double differential cross sections for light ion continuum reactions where no data is available.

  20. Interferometric measurement of angular motion

    NASA Astrophysics Data System (ADS)

    Peña Arellano, Fabián Erasmo; Panjwani, Hasnain; Carbone, Ludovico; Speake, Clive C.

    2013-04-01

    This paper describes the design and realization of a homodyne polarization interferometer for measuring angular motion. The optical layout incorporates carefully designed cat's eye retroreflectors that maximize the measurable range of angular motion and facilitate initial alignment. The retroreflectors are optimized and numerically characterized in terms of defocus and spherical aberrations using Zemax software for optical design. The linearity of the measurement is then calculated in terms of the aberrations. The actual physical interferometer is realized as a compact device with optical components from stock and without relying on adjustable holders. Evaluation of its performance using a commercial autocollimator confirmed a reproducibility within 0.1%, a non-linearity of less than 1 ppm with respect to the autocollimator, an upper limit to its sensitivity of about 5 × 10-11 rad/sqrt{textrm {Hz}} from audioband down to 100 mHz and an angular measurement range of more than ±1°.

  1. Interferometric measurement of angular motion.

    PubMed

    Peña Arellano, Fabián Erasmo; Panjwani, Hasnain; Carbone, Ludovico; Speake, Clive C

    2013-04-01

    This paper describes the design and realization of a homodyne polarization interferometer for measuring angular motion. The optical layout incorporates carefully designed cat's eye retroreflectors that maximize the measurable range of angular motion and facilitate initial alignment. The retroreflectors are optimized and numerically characterized in terms of defocus and spherical aberrations using Zemax software for optical design. The linearity of the measurement is then calculated in terms of the aberrations. The actual physical interferometer is realized as a compact device with optical components from stock and without relying on adjustable holders. Evaluation of its performance using a commercial autocollimator confirmed a reproducibility within 0.1%, a non-linearity of less than 1 ppm with respect to the autocollimator, an upper limit to its sensitivity of about 5 × 10(-11) rad/Hz from audioband down to 100 mHz and an angular measurement range of more than ±1°.

  2. Angular momentum in human walking.

    PubMed

    Herr, Hugh; Popovic, Marko

    2008-02-01

    Angular momentum is a conserved physical quantity for isolated systems where no external moments act about a body's center of mass (CM). However, in the case of legged locomotion, where the body interacts with the environment (ground reaction forces), there is no a priori reason for this relationship to hold. A key hypothesis in this paper is that angular momentum is highly regulated throughout the walking cycle about all three spatial directions [|Lt| approximately 0], and therefore horizontal ground reaction forces and the center of pressure trajectory can be explained predominantly through an analysis that assumes zero net moment about the body's CM. Using a 16-segment human model and gait data for 10 study participants, we found that calculated zero-moment forces closely match experimental values (Rx2=0.91; Ry2=0.90). Additionally, the centroidal moment pivot (point where a line parallel to the ground reaction force, passing through the CM, intersects the ground) never leaves the ground support base, highlighting how closely the body regulates angular momentum. Principal component analysis was used to examine segmental contributions to whole-body angular momentum. We found that whole-body angular momentum is small, despite substantial segmental momenta, indicating large segment-to-segment cancellations ( approximately 95% medio-lateral, approximately 70% anterior-posterior and approximately 80% vertical). Specifically, we show that adjacent leg-segment momenta are balanced in the medio-lateral direction (left foot momentum cancels right foot momentum, etc.). Further, pelvis and abdomen momenta are balanced by leg, chest and head momenta in the anterior-posterior direction, and leg momentum is balanced by upper-body momentum in the vertical direction. Finally, we discuss the determinants of gait in the context of these segment-to-segment cancellations of angular momentum.

  3. Perturbed Trojan satellites

    NASA Astrophysics Data System (ADS)

    Morais, M. H. M.; Murray, C. D.

    1999-09-01

    We present some mechanisms that can lead to instability of initially small eccentricity Trojan-type orbits associated with planetary satellites. Dermott & Murray (1981) showed that in the context of the hierarchical restricted three-body problem (M>> m), stable small eccentricity coorbital motion associated with the mass m, occurs within a region of relative width in semi-major axis a_s=0.74 epsilon (where epsilon is the dimensionless Hill's radius). However, for large eccentricities, the size of the stable coorbital region shrinks as a_s=4 (epsilon /e)(1/2) epsilon (Namouni 1999). The perturbations from other nearby bodies can cause increases in both eccentricity and semi-major axis, leading to ejection from the coorbital region via collisions with the parent body or a nearby perturber. We show that mean motion resonances among saturnian satellites can cause chaotic diffusion of both the eccentricity and the semi-major axis of their associated Trojan orbits. Moreover, we show that secular resonances inside the coorbital regions of some uranian and saturnian satellites can induce significant increases in the eccentricity of Trojan objects. A better insight into the complicated dynamics exhibited by Trojan objects when they are being subject to perturbations is fundamental to be able to assess the likelihood of finding real examples of these configurations. Dermott & Murray (1981). Icarus 48, 1-11. Namouni (1999). Icarus 137, 293-314.

  4. Covariant Bardeen perturbation formalism

    NASA Astrophysics Data System (ADS)

    Vitenti, S. D. P.; Falciano, F. T.; Pinto-Neto, N.

    2014-05-01

    In a previous work we obtained a set of necessary conditions for the linear approximation in cosmology. Here we discuss the relations of this approach with the so-called covariant perturbations. It is often argued in the literature that one of the main advantages of the covariant approach to describe cosmological perturbations is that the Bardeen formalism is coordinate dependent. In this paper we will reformulate the Bardeen approach in a completely covariant manner. For that, we introduce the notion of pure and mixed tensors, which yields an adequate language to treat both perturbative approaches in a common framework. We then stress that in the referred covariant approach, one necessarily introduces an additional hypersurface choice to the problem. Using our mixed and pure tensors approach, we are able to construct a one-to-one map relating the usual gauge dependence of the Bardeen formalism with the hypersurface dependence inherent to the covariant approach. Finally, through the use of this map, we define full nonlinear tensors that at first order correspond to the three known gauge invariant variables Φ, Ψ and Ξ, which are simultaneously foliation and gauge invariant. We then stress that the use of the proposed mixed tensors allows one to construct simultaneously gauge and hypersurface invariant variables at any order.

  5. Controlling the Spins Angular Momentum in Ferromagnets with Sequences of Picosecond Acoustic Pulses

    PubMed Central

    Kim, Ji-Wan; Vomir, Mircea; Bigot, Jean-Yves

    2015-01-01

    Controlling the angular momentum of spins with very short external perturbations is a key issue in modern magnetism. For example it allows manipulating the magnetization for recording purposes or for inducing high frequency spin torque oscillations. Towards that purpose it is essential to modify and control the angular momentum of the magnetization which precesses around the resultant effective magnetic field. That can be achieved with very short external magnetic field pulses or using intrinsically coupled magnetic structures, resulting in a transfer of spin torque. Here we show that using picosecond acoustic pulses is a versatile and efficient way of controlling the spin angular momentum in ferromagnets. Two or three acoustic pulses, generated by femtosecond laser pulses, allow suppressing or enhancing the magnetic precession at any arbitrary time by precisely controlling the delays and amplitudes of the optical pulses. A formal analogy with a two dimensional pendulum allows us explaining the complex trajectory of the magnetic vector perturbed by the acoustic pulses. PMID:25687970

  6. Controlling the spins angular momentum in ferromagnets with sequences of picosecond acoustic pulses.

    PubMed

    Kim, Ji-Wan; Vomir, Mircea; Bigot, Jean-Yves

    2015-02-17

    Controlling the angular momentum of spins with very short external perturbations is a key issue in modern magnetism. For example it allows manipulating the magnetization for recording purposes or for inducing high frequency spin torque oscillations. Towards that purpose it is essential to modify and control the angular momentum of the magnetization which precesses around the resultant effective magnetic field. That can be achieved with very short external magnetic field pulses or using intrinsically coupled magnetic structures, resulting in a transfer of spin torque. Here we show that using picosecond acoustic pulses is a versatile and efficient way of controlling the spin angular momentum in ferromagnets. Two or three acoustic pulses, generated by femtosecond laser pulses, allow suppressing or enhancing the magnetic precession at any arbitrary time by precisely controlling the delays and amplitudes of the optical pulses. A formal analogy with a two dimensional pendulum allows us explaining the complex trajectory of the magnetic vector perturbed by the acoustic pulses.

  7. Non-Colinearity of Angular Velocity and Angular Momentum

    ERIC Educational Resources Information Center

    Burr, A. F.

    1974-01-01

    Discusses the principles, construction, and operation of an apparatus which serves to demonstrate the non-colinearity of the angular velocity and momentum vectors as well as the inertial tensors. Applications of the apparatus to teaching of advanced undergraduate mechanics courses are recommended. (CC)

  8. Solar cell angular position transducer

    NASA Technical Reports Server (NTRS)

    Sandford, M. C.; Gray, D. L. (Inventor)

    1980-01-01

    An angular position transducer utilizing photocells and a light source is disclosed. The device uses a fully rotatable baffle which is connected via an actuator shaft to the body whose rotational displacement is to be measured. The baffle blocks the light path between the light source and the photocells so that a constant semicircular beam of light reaches the photocells. The current produced by the photocells is fed through a resistor, a differential amplifier measures the voltage drop across the resistor which indicates the angular position of the actuator shaft and hence of the object.

  9. Automated Angular Momentum Recoupling Algebra

    NASA Astrophysics Data System (ADS)

    Williams, H. T.; Silbar, Richard R.

    1992-04-01

    We present a set of heuristic rules for algebraic solution of angular momentum recoupling problems. The general problem reduces to that of finding an optimal path from one binary tree (representing the angular momentum coupling scheme for the reduced matrix element) to another (representing the sub-integrals and spin sums to be done). The method lends itself to implementation on a microcomputer, and we have developed such an implementation using a dialect of LISP. We describe both how our code, called RACAH, works and how it appears to the user. We illustrate the use of RACAH for several transition and scattering amplitude matrix elements occurring in atomic, nuclear, and particle physics.

  10. The Angular Structure of Four-Image Gravitational Lenses

    NASA Astrophysics Data System (ADS)

    Turner, C. M.; Keeton, C. R.; Kochanek, C. S.

    2002-12-01

    Using four-image gravitational lenses in the CfA-Arizona Space Telescope Lens Survey, we probe the angular structure of lens galaxy mass distributions. The models show the lens potential is successfully constrained for four-image lenses. The largest contribution to shear perturbations is found outside of the lens' Einstein ring, which suggests a dramatic, outlying mass component. We find strong evidence that most lens galaxies have extended, flattened dark matter halos. CMT acknowledges support from the NSF/REU program at the University of Chicago's Department of Physics. CRK acknowledges support from a Hubble Fellowship grant, awarded through STScI.

  11. RadSearch: a RIS/PACS integrated query tool

    NASA Astrophysics Data System (ADS)

    Tsao, Sinchai; Documet, Jorge; Moin, Paymann; Wang, Kevin; Liu, Brent J.

    2008-03-01

    Radiology Information Systems (RIS) contain a wealth of information that can be used for research, education, and practice management. However, the sheer amount of information available makes querying specific data difficult and time consuming. Previous work has shown that a clinical RIS database and its RIS text reports can be extracted, duplicated and indexed for searches while complying with HIPAA and IRB requirements. This project's intent is to provide a software tool, the RadSearch Toolkit, to allow intelligent indexing and parsing of RIS reports for easy yet powerful searches. In addition, the project aims to seamlessly query and retrieve associated images from the Picture Archiving and Communication System (PACS) in situations where an integrated RIS/PACS is in place - even subselecting individual series, such as in an MRI study. RadSearch's application of simple text parsing techniques to index text-based radiology reports will allow the search engine to quickly return relevant results. This powerful combination will be useful in both private practice and academic settings; administrators can easily obtain complex practice management information such as referral patterns; researchers can conduct retrospective studies with specific, multiple criteria; teaching institutions can quickly and effectively create thorough teaching files.

  12. Automatic programming of binary morphological machines by PAC learning

    NASA Astrophysics Data System (ADS)

    Barrera, Junior; Tomita, Nina S.; Correa da Silva, Flavio S.; Terada, Routo

    1995-08-01

    Binary image analysis problems can be solved by set operators implemented as programs for a binary morphological machine (BMM). This is a very general and powerful approach to solve this type of problem. However, the design of these programs is not a task manageable by nonexperts on mathematical morphology. In order to overcome this difficulty we have worked on tools that help users describe their goals at higher levels of abstraction and to translate them into BMM programs. Some of these tools are based on the representation of the goals of the user as a collection of input-output pairs of images and the estimation of the target operator from these data. PAC learning is a well suited methodology for this task, since in this theory 'concepts' are represented as Boolean functions that are equivalent to set operators. In order to apply this technique in practice we must have efficient learning algorithms. In this paper we introduce two PAC learning algorithms, both are based on the minimal representation of Boolean functions, which has a straightforward translation to the canonical decomposition of set operators. The first algorithm is based on the classical Quine-McCluskey algorithm for the simplification of Boolean functions, and the second one is based on a new idea for the construction of Boolean functions: the incremental splitting of intervals. We also present a comparative complexity analysis of the two algorithms. Finally, we give some application examples.

  13. Energy and angular momentum transfer in binary galaxies

    NASA Technical Reports Server (NTRS)

    Namboodiri, P. M. S.; Kochhar, R. K.

    1990-01-01

    The authors numerically studied tidal effects of a massive perturber on a satellite galaxy. The model consists of a spherical satellite galaxy and a point mass perturber and the encounter is non-penetrating. A wide range of density ratios and eccentricities of the relative orbits have been considered. The disruption of the satellite galaxy has been observed when the numerical value of the fractional change in the energy is greater than two. The changes in the energy and angular momentum show smooth variation in the case of unbound orbits and irregular variation in the bound orbit cases. It is shown that for a constant pericentral distance, increasing the density ratio decreases the tidal effects; and for a given density ratio an increase in the eccentricity decreases the tidal effects.

  14. Construct Reliability of the Probability of Adoption of Change (PAC) Model.

    ERIC Educational Resources Information Center

    Creamer, E. G.; And Others

    1991-01-01

    Describes Probability of Adoption of Change (PAC) model, theoretical paradigm for explaining likelihood of successful adoption of planned change initiatives in student affairs. Reports on PAC construct reliability from survey of 62 Chief Student Affairs Officers. Discusses two refinements to the model: merger of leadership and top level support…

  15. How to Develop PACs. Performance and Competency-based Student Materials.

    ERIC Educational Resources Information Center

    Rouse, Bill, Comp.

    This booklet is designed for developing performance and competency-based student materials (PACs). The PAC, an instructional tool that focuses on helping students master a specific objective, lends itself to vocational instruction. The first nine sections of the guide, consisting of information to assist teachers in gathering background materials…

  16. 75 FR 55777 - Pro-Pac Distributing Corp., Provisional Acceptance of a Settlement Agreement and Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-14

    ... COMMISSION Pro-Pac Distributing Corp., Provisional Acceptance of a Settlement Agreement and Order AGENCY... Agreement with Pro-Pac Distributing Corp., containing a civil penalty of $125,000.00. DATES: Any interested person may ask the Commission not to accept this agreement or otherwise comment on its contents by...

  17. Planning, expectation, and image evaluation for PACS at the University of Iowa Hospitals and Clinics

    NASA Astrophysics Data System (ADS)

    Franken, E. A., Jr.; Smith, Wilbur L.; Berbaum, Kevin S.; Owen, David A.; Hilsenrath, Peter

    1990-08-01

    Our strategy in studying PACS is to evaluate its clinical implementation working with equipment supplied by an established manufacturer. Fiscal and personnel resources required to design and integrate the hardware components and operational software to develop a functional PACS precluded a bottom up development approach at our institution. Imaging equipment vendors possess more abundant design development resources for this task and therefore can support a more rapid development of the initial components of PACS. For this reason we have chosen to serve as a beta test site to study the viability of the basic PACS components in a clinical setting. Our efforts primarily focus on: (1) image quality; (2) cost effectiveness; (3) PACS/HIS/RIS integration; (4) equipment and software reliability; and (5) overall system performance. The results of our studies are shared with the vendor for future PACS development and refi nement. To attain our investigational goals we have formed an interdisciplinary team of Radiologists, Perceptual Psychologist, Economist, Electrical and Industrial Engineers, Hospital Information System personnel and key departmental administrative staff. For several reasons Pediatric Radiology was targeted as the initial area for our PACS study: a small area representative of the overall operation,tight operational controls and willingness of physicians. We used a step-wise approach, the first step being the installation of PACS exclusively within the physical confines of Pediatric Radiology.

  18. OpenSourcePACS: an extensible infrastructure for medical image management.

    PubMed

    Bui, Alex A T; Morioka, Craig; Dionisio, John David N; Johnson, David B; Sinha, Usha; Ardekani, Siamak; Taira, Ricky K; Aberle, Denise R; El-Saden, Suzie; Kangarloo, Hooshang

    2007-01-01

    The development of comprehensive picture archive and communication systems (PACS) has mainly been limited to proprietary developments by vendors, though a number of freely available software projects have addressed specific image management tasks. The openSourcePACS project aims to provide an open source, common foundation upon which not only can a basic PACS be readily implemented, but to also support the evolution of new PACS functionality through the development of novel imaging applications and services. openSourcePACS consists of four main software modules: 1) image order entry, which enables the ordering and tracking of structured image requisitions; 2) an agent-based image server framework that coordinates distributed image services including routing, image processing, and querying beyond the present digital image and communications in medicine (DICOM) capabilities; 3) an image viewer, supporting standard display and image manipulation tools, DICOM presentation states, and structured reporting; and 4) reporting and result dissemination, supplying web-based widgets for creating integrated reports. All components are implemented using Java to encourage cross-platform deployment. To demonstrate the usage of openSourcePACS, a preliminary application supporting primary care/specialist communication was developed and is described herein. Ultimately, the goal of openSourcePACS is to promote the wide-scale development and usage of PACS and imaging applications within academic and research communities.

  19. Noncontact measurement of angular deflection

    NASA Technical Reports Server (NTRS)

    Bryant, E. L.

    1978-01-01

    Technique for measuring instantaneous angular deflection of object requires no physical contact. Technique utilizes two flat refractors, converging lens, and different photocell. Distinction of method is its combination of optical and electromechanical components into feedback system in which measurement error is made to approach zero. Application is foreseen in measurement of torsional strain.

  20. Olympic Wrestling and Angular Momentum.

    ERIC Educational Resources Information Center

    Carle, Mark

    1988-01-01

    Reported is the use of a wrestling photograph in a noncalculus introductory physics course. The photograph presents a maneuver that could serve as an example for a discussion on equilibrium, forces, torque, and angular motion. Provided are some qualitative thoughts as well as quantitative calculations. (YP)

  1. Spatial Angular Compounding of Photoacoustic Images.

    PubMed

    Kang, Hyun Jae; Bell, Muyinatu A Lediju; Guo, Xiaoyu; Boctor, Emad M

    2016-08-01

    Photoacoustic (PA) images utilize pulsed lasers and ultrasound transducers to visualize targets with higher optical absorption than the surrounding medium. However, they are susceptible to acoustic clutter and background noise artifacts that obfuscate biomedical structures of interest. We investigated three spatial-angular compounding methods to improve PA image quality for biomedical applications, implemented by combining multiple images acquired as an ultrasound probe was rotated about the elevational axis with the laser beam and target fixed. Compounding with conventional averaging was based on the pose information of each PA image, while compounding with weighted and selective averaging utilized both the pose and image content information. Weighted-average compounding enhanced PA images with the least distortion of signal size, particularly when there were large (i.e., 2.5 mm and 7 (°)) perturbations from the initial probe position. Selective-average compounding offered the best improvement in image quality with up 181, 1665, and 1568 times higher contrast, CNR, and SNR, respectively, compared to the mean values of individual PA images. The three presented spatial compounding methods have promising potential to enhance image quality in multiple photoacoustic applications. PMID:26890642

  2. Altered Circadian Food Anticipatory Activity Rhythms in PACAP Receptor 1 (PAC1) Deficient Mice.

    PubMed

    Hannibal, Jens; Georg, Birgitte; Fahrenkrug, Jan

    2016-01-01

    Light signals from intrinsically photosensitive retinal ganglion cells (ipRGCs) entrain the circadian clock and regulate negative masking. Two neurotransmitters, glutamate and Pituitary Adenylate Cyclase Activating Polypeptide (PACAP), found in the ipRGCs transmit light signals to the brain via glutamate receptors and the specific PACAP type 1 (PAC1) receptor. Light entrainment occurs during the twilight zones and has little effect on clock phase during daytime. When nocturnal animals have access to food only for a few hours during the resting phase at daytime, they adapt behavior to the restricted feeding (RF) paradigm and show food anticipatory activity (FAA). A recent study in mice and rats demonstrating that light regulates FAA prompted us to investigate the role of PACAP/PAC1 signaling in the light mediated regulation of FAA. PAC1 receptor knock out (PAC1-/-) and wild type (PAC1+/+) mice placed in running wheels were examined in a full photoperiod (FPP) of 12:12 h light/dark (LD) and a skeleton photoperiod (SPP) 1:11:1:11 h L:DD:L:DD at 300 and 10 lux light intensity. Both PAC1-/- mice and PAC1+/+ littermates entrained to FPP and SPP at both light intensities. However, when placed in RF with access to food for 4-5 h during the subjective day, a significant change in behavior was observed in PAC1-/- mice compared to PAC1+/+ mice. While PAC1-/- mice showed similar FAA as PAC1+/+ animals in FPP at 300 lux, PAC1-/- mice demonstrated an advanced onset of FAA with a nearly 3-fold increase in amplitude compared to PAC1+/+ mice when placed in SPP at 300 lux. The same pattern of FAA was observed at 10 lux during both FPP and SPP. The present study indicates a role of PACAP/PAC1 signaling during light regulated FAA. Most likely, PACAP found in ipRGCs mediating non-image forming light information to the brain is involved.

  3. Altered Circadian Food Anticipatory Activity Rhythms in PACAP Receptor 1 (PAC1) Deficient Mice

    PubMed Central

    Hannibal, Jens; Georg, Birgitte; Fahrenkrug, Jan

    2016-01-01

    Light signals from intrinsically photosensitive retinal ganglion cells (ipRGCs) entrain the circadian clock and regulate negative masking. Two neurotransmitters, glutamate and Pituitary Adenylate Cyclase Activating Polypeptide (PACAP), found in the ipRGCs transmit light signals to the brain via glutamate receptors and the specific PACAP type 1 (PAC1) receptor. Light entrainment occurs during the twilight zones and has little effect on clock phase during daytime. When nocturnal animals have access to food only for a few hours during the resting phase at daytime, they adapt behavior to the restricted feeding (RF) paradigm and show food anticipatory activity (FAA). A recent study in mice and rats demonstrating that light regulates FAA prompted us to investigate the role of PACAP/PAC1 signaling in the light mediated regulation of FAA. PAC1 receptor knock out (PAC1-/-) and wild type (PAC1+/+) mice placed in running wheels were examined in a full photoperiod (FPP) of 12:12 h light/dark (LD) and a skeleton photoperiod (SPP) 1:11:1:11 h L:DD:L:DD at 300 and 10 lux light intensity. Both PAC1-/- mice and PAC1+/+ littermates entrained to FPP and SPP at both light intensities. However, when placed in RF with access to food for 4–5 h during the subjective day, a significant change in behavior was observed in PAC1-/- mice compared to PAC1+/+ mice. While PAC1-/- mice showed similar FAA as PAC1+/+ animals in FPP at 300 lux, PAC1-/- mice demonstrated an advanced onset of FAA with a nearly 3-fold increase in amplitude compared to PAC1+/+ mice when placed in SPP at 300 lux. The same pattern of FAA was observed at 10 lux during both FPP and SPP. The present study indicates a role of PACAP/PAC1 signaling during light regulated FAA. Most likely, PACAP found in ipRGCs mediating non-image forming light information to the brain is involved. PMID:26757053

  4. Altered Circadian Food Anticipatory Activity Rhythms in PACAP Receptor 1 (PAC1) Deficient Mice.

    PubMed

    Hannibal, Jens; Georg, Birgitte; Fahrenkrug, Jan

    2016-01-01

    Light signals from intrinsically photosensitive retinal ganglion cells (ipRGCs) entrain the circadian clock and regulate negative masking. Two neurotransmitters, glutamate and Pituitary Adenylate Cyclase Activating Polypeptide (PACAP), found in the ipRGCs transmit light signals to the brain via glutamate receptors and the specific PACAP type 1 (PAC1) receptor. Light entrainment occurs during the twilight zones and has little effect on clock phase during daytime. When nocturnal animals have access to food only for a few hours during the resting phase at daytime, they adapt behavior to the restricted feeding (RF) paradigm and show food anticipatory activity (FAA). A recent study in mice and rats demonstrating that light regulates FAA prompted us to investigate the role of PACAP/PAC1 signaling in the light mediated regulation of FAA. PAC1 receptor knock out (PAC1-/-) and wild type (PAC1+/+) mice placed in running wheels were examined in a full photoperiod (FPP) of 12:12 h light/dark (LD) and a skeleton photoperiod (SPP) 1:11:1:11 h L:DD:L:DD at 300 and 10 lux light intensity. Both PAC1-/- mice and PAC1+/+ littermates entrained to FPP and SPP at both light intensities. However, when placed in RF with access to food for 4-5 h during the subjective day, a significant change in behavior was observed in PAC1-/- mice compared to PAC1+/+ mice. While PAC1-/- mice showed similar FAA as PAC1+/+ animals in FPP at 300 lux, PAC1-/- mice demonstrated an advanced onset of FAA with a nearly 3-fold increase in amplitude compared to PAC1+/+ mice when placed in SPP at 300 lux. The same pattern of FAA was observed at 10 lux during both FPP and SPP. The present study indicates a role of PACAP/PAC1 signaling during light regulated FAA. Most likely, PACAP found in ipRGCs mediating non-image forming light information to the brain is involved. PMID:26757053

  5. Three-component competitive adsorption model for flow-through PAC systems. 2. Model application to a PAC/membrane system.

    PubMed

    Li, Qilin; Mariñas, Benito J; Snoeyink, Vernon L; Campos, Carlos

    2003-07-01

    A three-component competitive adsorption kinetic model, developed and validated in part 1 of this study, was applied to a continuous-flow PAC/membrane system to study the effects of various system and operating parameters on organic removal. The model quantitatively describes the two competitive adsorption mechanisms that occur during adsorption of trace organic compounds by powdered activated carbon (PAC) in flow-through systems where the PAC is retained in the system: pore blockage and direct competition for adsorption sites. Model simulations were conducted to investigate the effects of influent water composition, membrane cleaning water quality, PAC pore size distribution, and system operation conditions such as hydraulic retention time, membrane cleaning interval, and PAC dosing method on treatment efficiency. Effects of these factors on adsorption capacity as well as surface diffusion rate and consequent removal of the trace organic compound were discussed. It was found that optimal operating conditions for maximum trace organic compound removal must be determined on the basis of the adsorption properties and concentrations of the competing compounds in the influent. For the conditions investigated in this study, the small strongly competing compound, p-DCB, had greater impact on atrazine removal than the large pore-blocking compound, PSS-1.8k. Various process design and operating parameters had complex and interrelated effects on the impact of competitive adsorption and corresponding trace contaminant removal efficiency in hybrid PAC/membrane systems. PMID:12875407

  6. Medical Image Resource Center--making electronic teaching files from PACS.

    PubMed

    Lim, C C Tchoyoson; Yang, Guo Liang; Nowinski, Wieslaw L; Hui, Francis

    2003-12-01

    A picture archive and communications system (PACS) is a rich source of images and data suitable for creating electronic teaching files (ETF). However, the potential for PACS to support nonclinical applications has not been fully realized: at present there is no mechanism for PACS to identify and store teaching files; neither is there a standardized method for sharing such teaching images. The Medical Image Resource Center (MIRC) is a new central image repository that defines standards for data exchange among different centers. We developed an ETF server that retrieves digital imaging and communication in medicine (DICOM) images from PACS, and enables users to create teaching files that conform to the new MIRC schema. We test-populated our ETF server with illustrative images from the clinical case load of the National Neuroscience Institute, Singapore. Together, PACS and MIRC have the potential to benefit radiology teaching and research.

  7. [Study on the distributed integration of the HIS and PACS based on CORBA].

    PubMed

    Zhang, Quanhai; Shi, Pengfei

    2004-02-01

    In medical clinical practice, physicians need to acquire the image and text information of the patient. All the information will be of benefit for physicians to diagnose disease, improve clinical treatment, and do research work. But the information is distributed in different systems, such as medical image information in PACS (Picture Archiving and Communication System) and text records in HIS (Hospital Information System). Today many hospitals are suffering from lack of an integrated system with PACS and HIS. This paper compares PACS with HIS and puts forward a distributed integration method of integrating the PACS and HIS with the prevailing WWW technology. In such a method, the image and the text information are regarded as the common object and the operation whereon as the object operation. Thus the method integrates the PACS with HIS effectively and implements the information resources sharing with the use of web technology.

  8. Derivatives of Procaspase-Activating Compound 1 (PAC-1) and their Anticancer Activities.

    PubMed

    Roth, Howard S; Hergenrother, Paul J

    2016-01-01

    PAC-1 induces the activation of procaspase-3 in vitro and in cell culture by chelation of inhibitory labile zinc ions via its ortho-hydroxy-N-acylhydrazone moiety. First reported in 2006, PAC-1 has shown promise in cell culture and animal models of cancer, and a Phase I clinical trial in cancer patients began in March 2015 (NCT02355535). Because of the considerable interest in this compound and a well-defined structure-activity relationship, over 1000 PAC-1 derivatives have been synthesized in an effort to vary pharmacological properties such as potency and pharmacokinetics. This article provides a comprehensive examination of all PAC-1 derivatives reported to date. A survey of PAC-1 derivative libraries is provided, with an indepth discussion of four derivatives on which extensive studies have been performed. PMID:26630918

  9. PACS--and beyond. A journey to the digital promised land.

    PubMed

    Viau, Mark A

    2004-01-01

    A successful picture archiving and communication system (PACS) integration depends on much more than the technology; marketing also plays a large role. This fact was evident from the inception of the PACS project at Boca Raton Community Hospital (BRCH). Strategic and effective marketing efforts should target technologists, nurses, physicians (including radiologists), administration, and colleagues in other departments. The buy-in of these users is critical to the project's success. BRCH's first marketing effort took place during the initial PACS presentation made to the hospital's board of directors. Once approval was given and a 6-month implementation target was set, a strategic and effective marketing/education plan commenced. Posters, brochures, t-shirts, and promotional items were distributed in a coordinated effort to target hospital staff and referring physician offices. Through its "Got PACS?" branding and other identity materials, BRCH implemented a marketing plan that informed, educated, and engaged PACS users. PMID:15259686

  10. Fault tolerance techniques to assure data integrity in high-volume PACS image archives

    NASA Astrophysics Data System (ADS)

    He, Yutao; Huang, Lu J.; Valentino, Daniel J.; Wingate, W. Keith; Avizienis, Algirdas

    1995-05-01

    Picture archiving and communication systems (PACS) perform the systematic acquisition, archiving, and presentation of large quantities of radiological image and text data. In the UCLA Radiology PACS, for example, the volume of image data archived currently exceeds 2500 gigabytes. Furthermore, the distributed heterogeneous PACS is expected to have near real-time response, be continuously available, and assure the integrity and privacy of patient data. The off-the-shelf subsystems that compose the current PACS cannot meet these expectations; therefore fault tolerance techniques had to be incorporated into the system. This paper is to report our first-step efforts towards the goal and is organized as follows: First we discuss data integrity and identify fault classes under the PACS operational environment, then we describe auditing and accounting schemes developed for error-detection and analyze operational data collected. Finally, we outline plans for future research.

  11. Derivatives of Procaspase-Activating Compound 1 (PAC-1) and Anticancer Activities

    PubMed Central

    Roth, Howard S.; Hergenrother, Paul J.

    2016-01-01

    PAC-1 induces the activation of procaspase-3 in vitro and in cell culture by chelation of inhibitory labile zinc ions via its ortho-hydroxy-N-acylhydrazone moiety. First reported in 2006, PAC-1 has shown promise in cell culture and animal models of cancer, and a Phase I clinical trial in cancer patients began in March 2015 (NCT02355535). Because of the considerable interest in this compound and a well-defined structure-activity relationship, over 1000 PAC-1 derivatives have been synthesized in an effort to vary pharmacological properties such as potency and pharmacokinetics. This article provides a comprehensive examination of all PAC-1 derivatives reported to date. A survey of PAC-1 derivative libraries is provided, with an in-depth discussion of four derivatives on which extensive studies have been performed. PMID:26630918

  12. Grid-based medical image workflow and archiving for research and enterprise PACS applications

    NASA Astrophysics Data System (ADS)

    Erberich, Stephan G.; Dixit, Manasee; Chen, Vincent; Chervenak, Ann; Nelson, Marvin D.; Kesselmann, Carl

    2006-03-01

    PACS provides a consistent model to communicate and to store images with recent additions to fault tolerance and disaster reliability. However PACS still lacks fine granulated user based authentication and authorization, flexible data distribution, and semantic associations between images and their embedded information. These are critical components for future Enterprise operations in dynamic medical research and health care environments. Here we introduce a flexible Grid based model of a PACS in order to add these methods and to describe its implementation in the Children's Oncology Group (COG) Grid. The combination of existing standards for medical images, DICOM, and the abstraction to files and meta catalog information in the Grid domain provides new flexibility beyond traditional PACS design. We conclude that Grid technology demonstrates a reliable and efficient distributed informatics infrastructure which is well applicable to medical informatics as described in this work. Grid technology will provide new opportunities for PACS deployment and subsequently new medical image applications.

  13. Transition from partial to full PACS at a 450,000 exams/year hospital

    NASA Astrophysics Data System (ADS)

    Ro, Duk-Woo; Byun, Hong Sik; Choo, In W.; Kim, Bo K.; Lim, Jae H.

    1997-05-01

    The purpose of this paper is to describe the transition of a 1,100 beds tertiary hospital from 50 percent softcopy operation to full PACS operation. For the past 2 years, radiologists and clinicians have been using PACS to provide softcopy services to the outpatient clinics and inpatient wards of orthopedics surgery, neurosurgery and neurology as well as emergency room, surgical intensive care unit, medical intensive unit, pediatrics intensive care unit and neonatal intensive care unit. The examinations requested by these departments account for about 50 percent of hospital's radiological exams. In September 1996, we began the second phase of PACS implementation and installed additional workstations in the remaining wards and clinics, interfaced to PACS additional imaging modalities, and increased the capacity of both the image server and optical juke boxes. As of January 1997, we are in the final phase of moving away from conventional film system to full PACS operation.

  14. Medical Image Resource Center--making electronic teaching files from PACS.

    PubMed

    Lim, C C Tchoyoson; Yang, Guo Liang; Nowinski, Wieslaw L; Hui, Francis

    2003-12-01

    A picture archive and communications system (PACS) is a rich source of images and data suitable for creating electronic teaching files (ETF). However, the potential for PACS to support nonclinical applications has not been fully realized: at present there is no mechanism for PACS to identify and store teaching files; neither is there a standardized method for sharing such teaching images. The Medical Image Resource Center (MIRC) is a new central image repository that defines standards for data exchange among different centers. We developed an ETF server that retrieves digital imaging and communication in medicine (DICOM) images from PACS, and enables users to create teaching files that conform to the new MIRC schema. We test-populated our ETF server with illustrative images from the clinical case load of the National Neuroscience Institute, Singapore. Together, PACS and MIRC have the potential to benefit radiology teaching and research. PMID:14747933

  15. PACS--and beyond. A journey to the digital promised land.

    PubMed

    Viau, Mark A

    2004-01-01

    A successful picture archiving and communication system (PACS) integration depends on much more than the technology; marketing also plays a large role. This fact was evident from the inception of the PACS project at Boca Raton Community Hospital (BRCH). Strategic and effective marketing efforts should target technologists, nurses, physicians (including radiologists), administration, and colleagues in other departments. The buy-in of these users is critical to the project's success. BRCH's first marketing effort took place during the initial PACS presentation made to the hospital's board of directors. Once approval was given and a 6-month implementation target was set, a strategic and effective marketing/education plan commenced. Posters, brochures, t-shirts, and promotional items were distributed in a coordinated effort to target hospital staff and referring physician offices. Through its "Got PACS?" branding and other identity materials, BRCH implemented a marketing plan that informed, educated, and engaged PACS users.

  16. Communication: Semiclassical perturbation theory for the quantum diffractive scattering of atoms on thermal surfaces

    NASA Astrophysics Data System (ADS)

    Daon, Shauli; Pollak, Eli; Miret-Artés, S.

    2012-11-01

    Inspired by the semiclassical perturbation theory of Hubbard and Miller [J. Chem. Phys. 80, 5827 (1984), 10.1063/1.446609], we derive explicit expressions for the angular distribution of particles scattered from thermal surfaces. At very low surface temperature, the observed experimental background scattering is proportional to the spectral density of the phonons. The angular distribution is a sum of diffraction peaks and a broad background reflecting the spectral density. The theory is applied to measured angular distributions of Ne, Ar, and Kr scattered from a Cu(111) surface.

  17. Discrete reductive perturbation technique

    SciTech Connect

    Levi, Decio; Petrera, Matteo

    2006-04-15

    We expand a partial difference equation (P{delta}E) on multiple lattices and obtain the P{delta}E which governs its far field behavior. The perturbative-reductive approach is here performed on well-known nonlinear P{delta}Es, both integrable and nonintegrable. We study the cases of the lattice modified Korteweg-de Vries (mKdV) equation, the Hietarinta equation, the lattice Volterra-Kac-Van Moerbeke equation and a nonintegrable lattice KdV equation. Such reductions allow us to obtain many new P{delta}Es of the nonlinear Schroedinger type.

  18. Integrating organic micropollutant removal into tertiary filtration: Combining PAC adsorption with advanced phosphorus removal.

    PubMed

    Altmann, Johannes; Sperlich, Alexander; Jekel, Martin

    2015-11-01

    Direct addition of powdered activated carbon (PAC) to a deep-bed filter was investigated at pilot-scale as a single advanced treatment stage for simultaneous removal of organic micropollutants (OMPs) and phosphorus from secondary effluent. PAC doses of 10-50 mg/L were assessed with regard to their impacts on filter performance and removal of 15 selected OMPs over a period of 18 months. The PAC was effectively retained by the filter and had no negative effect on filter head loss. Filter runtime until particle breakthrough depended mainly on coagulant dose and did not decrease significantly due to the additional PAC load. Removal of suspended solids and phosphorus by coagulation was effective independent of the PAC dose. A PAC dose of 35 mg/L PAC was suitable to remove well-adsorbing OMPs (e.g. carbamazepine, diclofenac) by >80% and medium adsorbing OMPs (e.g. primidone, sulfamethoxazole) by 50-80%. Median removals were 50-80% for well-adsorbing and 30-50% for medium adsorbing OMPs with 20 mg/L PAC. Abatement of all OMPs was low (<50%) with 10 mg/L PAC, possibly because of the high effluent organic matter content (median dissolved organic carbon (DOC) concentrations of 11.2 mg/L). In addition to adsorptive removal, relevant concentration decreases of certain OMPs (e.g. 4-formylaminoantipyrine) were attributed to biological transformation in the filter. Adsorption onto accumulating PAC in the top layer of the filter bed led to improved OMP adsorption with increasing filter runtime. The comparison of OMP removal in the pilot filter with laboratory adsorption tests demonstrates that batch test results can be applied to estimate adsorptive OMP removal in real applications.

  19. Integrating organic micropollutant removal into tertiary filtration: Combining PAC adsorption with advanced phosphorus removal.

    PubMed

    Altmann, Johannes; Sperlich, Alexander; Jekel, Martin

    2015-11-01

    Direct addition of powdered activated carbon (PAC) to a deep-bed filter was investigated at pilot-scale as a single advanced treatment stage for simultaneous removal of organic micropollutants (OMPs) and phosphorus from secondary effluent. PAC doses of 10-50 mg/L were assessed with regard to their impacts on filter performance and removal of 15 selected OMPs over a period of 18 months. The PAC was effectively retained by the filter and had no negative effect on filter head loss. Filter runtime until particle breakthrough depended mainly on coagulant dose and did not decrease significantly due to the additional PAC load. Removal of suspended solids and phosphorus by coagulation was effective independent of the PAC dose. A PAC dose of 35 mg/L PAC was suitable to remove well-adsorbing OMPs (e.g. carbamazepine, diclofenac) by >80% and medium adsorbing OMPs (e.g. primidone, sulfamethoxazole) by 50-80%. Median removals were 50-80% for well-adsorbing and 30-50% for medium adsorbing OMPs with 20 mg/L PAC. Abatement of all OMPs was low (<50%) with 10 mg/L PAC, possibly because of the high effluent organic matter content (median dissolved organic carbon (DOC) concentrations of 11.2 mg/L). In addition to adsorptive removal, relevant concentration decreases of certain OMPs (e.g. 4-formylaminoantipyrine) were attributed to biological transformation in the filter. Adsorption onto accumulating PAC in the top layer of the filter bed led to improved OMP adsorption with increasing filter runtime. The comparison of OMP removal in the pilot filter with laboratory adsorption tests demonstrates that batch test results can be applied to estimate adsorptive OMP removal in real applications. PMID:26210030

  20. Digital Light Box, One Of The Integral Pieces Of PACS

    NASA Astrophysics Data System (ADS)

    Rutherford, Harold G.; Gray, Michael J.

    1983-05-01

    A workable PACS system consists of several discrete assemblies which are linked together by data communication links for terminal and image data input and output. Two phases of development of a PACS system can be identified and labeled: emulation and enhancement. The latter is characterized by the observation "you do that so well, can you also do this?" Emulation, on the other hand, assures an accepted and working system. One of the key components of a PACS system is the emulation of the classical and ubiquitous "lightbox". This paper presents an emulation of the lightbox using a highspeed digital disk and video display on multiple high resolution monitors capable of 1024 x 1024 or 512 x 512 resolution pixel display. The emulation features are: a) loading and reloading in less than one second, b) access to between 800 and 3200 digital radiographs, and c) highspeed review forward and backward through this list of radiographs at rates up to 30 new images/second. Operation is under manual control both in rate and direction. This stresses the speed. The feature which makes this "lightbox" emulation desirable is the ability to dwell on a presently viewable display of digital radiographs with access to previous and following images in the study. One of the features desired in an emulation is that the components be "off the shelf". This means that existing hardware is used in the emulation. Software can then be generated based on known hardware. The emulation has flexibility of size: multi-image displays ranging from 2 or 3 images side by side to the piano-roll type endless display of an array with 4 images side-by-side and 3 rows visible at any one time. In addition, it has flexibility of resolution: radiographs displayable within a 256 x 256 pixel region to those displayable within a 1024 x 1024 pixel array as well as images which are much larger (4000 pixel by 4000 line chest radiograph scans) using a 1024 pixel by 1024 line window into the radiograph. The emulation of

  1. Quasi-periodic oscillations of perturbed tori

    NASA Astrophysics Data System (ADS)

    Parthasarathy, Varadarajan; Manousakis, Antonios; Kluźniak, Włodzimierz

    2016-05-01

    We performed axisymmetric hydrodynamical simulations of oscillating tori orbiting a non-rotating black hole. The tori in equilibrium were constructed with a constant distribution of angular momentum in a pseudo-Newtonian potential (Kluźniak-Lee). Motions of the torus were triggered by adding subsonic velocity fields: radial, vertical and diagonal to the tori in equilibrium. As the perturbed tori evolved in time, we measured L2 norm of density and obtained the power spectrum of L2 norm which manifested eigenfrequencies of tori modes. The most prominent modes of oscillation excited in the torus by a quasi-random perturbation are the breathing mode and the radial and vertical epicyclic modes. The radial and the plus modes, as well as the vertical and the breathing modes will have frequencies in an approximate 3:2 ratio if the torus is several Schwarzschild radii away from the innermost stable circular orbit. Results of our simulations may be of interest in the context of high-frequency quasi-periodic oscillations observed in stellar-mass black hole binaries, as well as in supermassive black holes.

  2. DrizzlePac 2.0 - Introducing New Features

    NASA Astrophysics Data System (ADS)

    Avila, R. J.; Hack, W.; Cara, M.; Borncamp, D.; Mack, J.; Smith, L.; Ubeda, L.

    2015-09-01

    The DrizzlePac package includes tasks for aligning and drizzling images taken with the Hubble Space Telescope. We present this release which includes new features that facilitate image alignment, sky matching, and adds support for new time dependent distortion solutions of the ACS instrument. The TweakReg task now includes capabilities for automatically aligning images which form part of a mosaic. In addition, new parameters make it easier to reject cosmic rays and other spurious detections from source catalogs used for alignment. The Astrodrizzle task has been improved with a new sky matching algorithm which makes producing mosaics easier than ever before. This new version supports an improved version of the ACS/WFC time-dependent distortion correction. There are also improvements to the GUI interfaces and some behind the scene bug fixes.

  3. The PacCAF Grid portal for the CDF experiment

    NASA Astrophysics Data System (ADS)

    Hou, Suen

    Distributed computing for the CDF experiment has been developed and is evolving towards shared resources on the computing Grid. Dedicated CAFs (CDF Analysis Farm) were constructed on Condor pools with a suit of services for user authentication, software distribution, and network connection to worker nodes.With the Condor Glide-in mechanism, the CAFs are extended to using dynamic worker pools collected from the Grid. The PacCAF (Pacific CAF) is the Glide CAF thus built to provide a single point portal to LCG (LHC ComputingGrid) and OSG (Open Science Grid) sites in the Pacific Asia region. We discuss the implementation and service as a late-binding solution towards Grid computing.

  4. Proceedings of the 22nd Particle Accelerator Conference (PAC'07)

    SciTech Connect

    N /A

    2007-08-01

    The twenty-second Particle Accelerator Conference, PAC'07, took place at the Albuquerque Convention Centre in Albuquerque, the largest city in New Mexico, from Monday to Friday, 2007 June 25 to 29. It was attended by over 1350 delegates from 25 different countries (63% North America, 24% Europe, 11% Asia and 2% Other), and was held under the auspices of the two professional societies that oversee and make holding this series of conferences possible, the Division of Physics of Beams within APS, and the Nuclear and Plasma Sciences Society within IEEE. As host of the conference, Los Alamos National Laboratory (LANL) is especially thanked for their many contributions and assistance both prior to and during the conference. The Convention Center was an ideal location for information sharing and discussions between the interdisciplinary aspects of the accelerator community, as well as for related meetings and ad-hoc 'rump' sessions.

  5. Benefits of cloud computing for PACS and archiving.

    PubMed

    Koch, Patrick

    2012-01-01

    The goal of cloud-based services is to provide easy, scalable access to computing resources and IT services. The healthcare industry requires a private cloud that adheres to government mandates designed to ensure privacy and security of patient data while enabling access by authorized users. Cloud-based computing in the imaging market has evolved from a service that provided cost effective disaster recovery for archived data to fully featured PACS and vendor neutral archiving services that can address the needs of healthcare providers of all sizes. Healthcare providers worldwide are now using the cloud to distribute images to remote radiologists while supporting advanced reading tools, deliver radiology reports and imaging studies to referring physicians, and provide redundant data storage. Vendor managed cloud services eliminate large capital investments in equipment and maintenance, as well as staffing for the data center--creating a reduction in total cost of ownership for the healthcare provider.

  6. Cermet sphere-pac concept for inert matrix fuel

    NASA Astrophysics Data System (ADS)

    Pouchon, M. A.; Nakamura, M.; Hellwig, Ch.; Ingold, F.; Degueldre, C.

    2003-06-01

    In the inert matrix fuel concept, plutonium reprocessed from spent fuel is burned in an inert matrix, e.g. yttria-stabilized zirconia. Coming from wet reprocessing, the internal gelation can perform an easy micro-spheres production. Utilization of these particles in a sphere-pac realizes a direct fuel production. Besides being economical, this direct usage offers an almost dustless fabrication. One disadvantage of yttria-stabilized zirconia as matrix is its low thermal conductivity. A further reduction by the macroscopic structure of a sphere bed seems unacceptable. This can be eluded by the insertion of a highly conducting phase. Similar to the cermet concept with the embedment of ceramic fuel into metal, the infiltration of a fine metal fraction into a coarse ceramic fuel fraction is studied here. The initial thermal conductivity shows much higher calculated values and the sintering behaviour is also clearly enhanced compared to the pure ceramic bed.

  7. Three-component competitive adsorption model for flow-through PAC systems. 1. Model development and verification with a PAC/membrane system.

    PubMed

    Li, Qilin; Mariñas, Benito J; Snoeyink, Vernon L; Campos, Carlos

    2003-07-01

    Natural organic matter (NOM) interferes with the adsorption of trace organic compounds on porous adsorbents such as powdered activated carbon (PAC) by pore blockage and direct competition for adsorption sites. The competitive effect of NOM in flow-through systems in which the retention time of the PAC is greater than the hydraulic retention time of the system can be magnified because NOM from the influent water can continue to adsorb on the PAC retained in the system. As a result, the adsorption capacity and the diffusion coefficient of trace compounds can decrease as NOM from the influent water accumulates. In this study, a dynamic three-component adsorption model was developed to quantitatively describe the removal of a trace compound from water in flow-through PAC processes. The system was simplified by using p-dichlorobenzene (p-DCB) to represent the NOM fraction that competes directly with the target trace organic atrazine for adsorption sites and by using poly(styrene sulfonate) (PSS-1.8k) to represent large, pore-blocking NOM. The model was based on the homogeneous surface diffusion assumption with the adsorption capacity of atrazine being gradually adjusted using a simplified version of the ideal adsorbed solution theory model developed in this study. The surface diffusion coefficients of atrazine and p-DCB were modeled as a function of the surface concentration of the pore-blocking compound, PSS-1.8k. The model was verified experimentally with a PAC/microfiltration (MF) system. The use of single-solute adsorption parameters obtained from batch isotherm and kinetic tests resulted in good model predictions for the adsorption of atrazine and the two model compounds under operating conditions typical of PAC/MF systems. The model will be applied to study various operating conditions and other system parameters of PAC/membrane systems in part 2 of this study. PMID:12875406

  8. Full-sky formulae for weak lensing power spectra from total angular momentum method

    NASA Astrophysics Data System (ADS)

    Yamauchi, Daisuke; Namikawa, Toshiya; Taruya, Atsushi

    2013-08-01

    We systematically derive full-sky formulae for the weak lensing power spectra generated by scalar, vector and tensor perturbations from the total angular momentum (TAM) method. Based on both the geodesic and geodesic deviation equations, we first give the gauge-invariant expressions for the deflection angle and Jacobi map as observables of the CMB lensing and cosmic shear experiments. We then apply the TAM method, originally developed in the theoretical studies of CMB, to a systematic derivation of the angular power spectra. The TAM representation, which characterizes the total angular dependence of the spatial modes projected along a line-of-sight, can carry all the information of the lensing modes generated by scalar, vector, and tensor metric perturbations. This greatly simplifies the calculation, and we present a complete set of the full-sky formulae for angular power spectra in both the E-/B-mode cosmic shear and gradient-/curl-mode lensing potential of deflection angle. Based on the formulae, we give illustrative examples of non-vanishing B-mode cosmic shear and curl-mode of deflection angle in the presence of the vector and tensor perturbations, and explicitly compute the power spectra.

  9. Perturbative unidirectional invisibility

    NASA Astrophysics Data System (ADS)

    Mostafazadeh, Ali

    2015-08-01

    We outline a general perturbative method of evaluating scattering features of finite-range complex potentials and use it to examine complex perturbations of a rectangular barrier potential. In optics, these correspond to modulated refractive index profiles of the form n (x ) =n0+f (x ) , where n0 is real, f (x ) is complex valued, and |f (x ) | ≪1 ≤n0 . We give a comprehensive description of the phenomenon of unidirectional invisibility for such media, proving five general theorems on its realization in P T -symmetric and non-P T -symmetric material. In particular, we establish the impossibility of unidirectional invisibility for P T -symmetric samples whose refractive index has a constant real part and show how a simple scaling transformation of a unidirectionally invisible P T -symmetric index profile with n0=1 may be used to generate a hierarchy of unidirectionally invisible P T -symmetric index profiles with n0>1 . The results pertaining to unidirectional invisibility for n0>1 open the way for the experimental studies of this phenomenon in a variety of active materials. As an application of our general results, we show that a medium with n (x ) =n0+ζ ei K x , ζ and K real, and |ζ |≪1 can support unidirectional invisibility only for n0=1 . We then construct unidirectionally invisible index profiles of the form n (x ) =n0+∑ℓzℓei Kℓx with zℓ complex, Kℓ real, | zℓ|≪1 , and n0>1 .

  10. Angular dependence of primordial trispectra and CMB spectral distortions

    NASA Astrophysics Data System (ADS)

    Shiraishi, Maresuke; Bartolo, Nicola; Liguori, Michele

    2016-10-01

    Under the presence of anisotropic sources in the inflationary era, the trispectrum of the primordial curvature perturbation has a very specific angular dependence between each wavevector that is distinguishable from the one encountered when only scalar fields are present, characterized by an angular dependence described by Legendre polynomials. We examine the imprints left by curvature trispectra on the TTμ bispectrum, generated by the correlation between temperature anisotropies (T) and chemical potential spectral distortions (μ) of the Cosmic Microwave Background (CMB). Due to the angular dependence of the primordial signal, the corresponding TTμ bispectrum strongly differs in shape from TTμ sourced by the usual gNL or τNL local trispectra, enabling us to obtain an unbiased estimation. From a Fisher matrix analysis, we find that, in a cosmic-variance-limited (CVL) survey of TTμ, a minimum detectable value of the quadrupolar Legendre coefficient is d2 ~ 0.01, which is 4 orders of magnitude better than the best value attainable from the TTTT CMB trispectrum. In the case of an anisotropic inflationary model with a f(phi)F2 interaction (coupling the inflaton field phi with a vector kinetic term F2), the size of the curvature trispectrum is related to that of quadrupolar power spectrum asymmetry, g*. In this case, a CVL measurement of TTμ makes it possible to measure g* down to 10‑3.

  11. PACS in the Utrecht University Hospital: final conclusions of the clinical evaluation

    NASA Astrophysics Data System (ADS)

    Wilmink, J. B.; ter Haar Romeny, Bart M.; Barneveld Binkhuysen, Frits H.; Achterberg, A. J.; Zuiderveld, Karel J.; Calkoen, P.; Kouwenberg, Jef M.

    1990-08-01

    In the past three years, a clinical evaluation of a PACS has been performed in the Utrecht University Hospital as part of the Dutch PACS project. The clinical evaluation focussed on the following aspects: technical evaluation of the prototype PACS equipment coupled to the HIS; diagnostic accuracy studies; studies concerning the impact on the organization of the radiology-department and the referring wards; and cost-savings analysis. Some of the results of these subprojects have already been presented at previous SPIE conferences. In this paper the general condusions are presented about the usefulness of the evaluated PAC-System in the daily routine of radiology department and clinic. By making available the images of radiological examinations fast, complete, reliable and continously on the ward, concrete improvements with regard to the current process could be realized. The possibilities of PACS caused an increasing enthousiasm among the clinicians. By the easier access to all images of their patients during 24 hours/day, they saw more images on the day of the examination and images could be more easily used at consultations of other specialists. The overall conclusion is positive, but a lot of work has to be done to transform PACS from an experimental setup into a routine production system on which a flimless hospital can be based. A complete PACS needs an inteffigent Image Management System, which indudes prefetching algorithms based on data from the Hospital Information System and automated procedures for removing obsolete images from the local buffers in the workstations. As yet PACS is very expensive, and the direct savings in the hospital cannot compensate for the high costs of investment. Possibly PACS can contribute to a shorter stay of patients in the hospital. This will lead to savings for government and health insurance companies and they can be expected to contribute to PAS implementation studies.

  12. Wireless-PDA-controlled image workflow from PACS: the next trend in the health care enterprise?

    NASA Astrophysics Data System (ADS)

    Erberich, Stephan G.; Documet, Jorge; Zhou, Michael Z.; Cao, Fei; Liu, Brent J.; Mogel, Greg T.; Huang, H. K.

    2003-05-01

    Image workflow in today's Picture Archiving and Communication Systems (PACS) is controlled from fixed Display Workstations (DW) using proprietary control interfaces. A remote access to the Hospital Information System (HIS) and Radiology Information System (RIS) for urgent patient information retrieval does not exist or gradually become available. The lack for remote access and workflow control for HIS and RIS is especially true when it comes to medical images of a PACS on Department or Hospital level. As images become more complex and data sizes expand rapidly with new image techniques like functional MRI, Mammography or routine spiral CT to name a few, the access and manageability becomes an important issue. Long image downloads or incomplete work lists cannot be tolerated in a busy health care environment. In addition, the domain of the PACS is no longer limited to the imaging department and PACS is also being used in the ER and emergency care units. Thus a prompt and secure access and manageability not only by the radiologist, but also from the physician becomes crucial to optimally utilize the PACS in the health care enterprise of the new millennium. The purpose of this paper is to introduce a concept and its implementation of a remote access and workflow control of the PACS combining wireless, Internet and Internet2 technologies. A wireless device, the Personal Digital Assistant (PDA), is used to communicate to a PACS web server that acts as a gateway controlling the commands for which the user has access to the PACS server. The commands implemented for this test-bed are query/retrieve of the patient list and study list including modality, examination, series and image selection and pushing any list items to a selected DW on the PACS network.

  13. Sphere-pac fuel development program. First semi-annual progress report, October 1979-March 1980

    SciTech Connect

    Felt, R.E.

    1980-05-01

    Development of processes by Exxon Nuclear Company, Inc. for fabricating spherical particle nuclear fuel (sphere-pac) during October 1979 through March 1980 is reported. The program surveyed available technology to develop an initial flowsheet as a design basis for process development. An 0.1 ton/day pilot plant was built to develop and demonstrate the fabrication of sphere-pac fuel. Process and equipment efforts have been directed towards the demonstration of processes and equipment necessary to fabricate sphere-pac fuel on a commercial scale.

  14. Hybrid perturbation scheme for wide beamwidth circularly polarized stacked patch microstrip antenna for satellite communication

    NASA Astrophysics Data System (ADS)

    Hossain, Mohammad Shakawat

    Circularly polarized microstrip antennas are popular for satellite communications due to their circularly polarized orientation. They are used frequently in modern day satellite communication. In order to achieve wide angular coverage in satellite communication, a wide beamwidth is required from the antenna. Traditional single layer microstrip antenna inherently demonstrates low angular beamwidth of approximately 600 to 800and thereby lacks wide angular coverage when used for satellite communication. The objective of this thesis is to design a single-fed stacked microstrip antenna using different perturbation techniques in order to achieve a wide angular beamwidth. This thesis presents a new design for a circularly polarized antenna based on the hybrid perturbation scheme. First, a method of stacked patch-ring with negative perturbation was used to generate a significantly larger beamwidth of 1060. The axial ratio (AR) bandwidth obtained is also significantly larger compared to the case when square rings are used as parasitic and driven rings with a single feed. A simulated impedance bandwidth (S11< - 10 dB) of 16%, 3 dB AR bandwidth of 8% and a peak gain of 8.65 dBic are obtained from this design. Next, a new design of stacked hybrid antenna is presented, which uses hybrid perturbations to generate circular polarization radiation. An enhanced beamwidth of 1260 was obtained. The simulation results are confirmed by the measured results.

  15. Canonical density matrix perturbation theory.

    PubMed

    Niklasson, Anders M N; Cawkwell, M J; Rubensson, Emanuel H; Rudberg, Elias

    2015-12-01

    Density matrix perturbation theory [Niklasson and Challacombe, Phys. Rev. Lett. 92, 193001 (2004)] is generalized to canonical (NVT) free-energy ensembles in tight-binding, Hartree-Fock, or Kohn-Sham density-functional theory. The canonical density matrix perturbation theory can be used to calculate temperature-dependent response properties from the coupled perturbed self-consistent field equations as in density-functional perturbation theory. The method is well suited to take advantage of sparse matrix algebra to achieve linear scaling complexity in the computational cost as a function of system size for sufficiently large nonmetallic materials and metals at high temperatures. PMID:26764847

  16. Cosmological perturbations in massive bigravity

    SciTech Connect

    Lagos, Macarena; Ferreira, Pedro G. E-mail: p.ferreira1@physics.ox.ac.uk

    2014-12-01

    We present a comprehensive analysis of classical scalar, vector and tensor cosmological perturbations in ghost-free massive bigravity. In particular, we find the full evolution equations and analytical solutions in a wide range of regimes. We show that there are viable cosmological backgrounds but, as has been found in the literature, these models generally have exponential instabilities in linear perturbation theory. However, it is possible to find stable scalar cosmological perturbations for a very particular choice of parameters. For this stable subclass of models we find that vector and tensor perturbations have growing solutions. We argue that special initial conditions are needed for tensor modes in order to have a viable model.

  17. Canonical density matrix perturbation theory.

    PubMed

    Niklasson, Anders M N; Cawkwell, M J; Rubensson, Emanuel H; Rudberg, Elias

    2015-12-01

    Density matrix perturbation theory [Niklasson and Challacombe, Phys. Rev. Lett. 92, 193001 (2004)] is generalized to canonical (NVT) free-energy ensembles in tight-binding, Hartree-Fock, or Kohn-Sham density-functional theory. The canonical density matrix perturbation theory can be used to calculate temperature-dependent response properties from the coupled perturbed self-consistent field equations as in density-functional perturbation theory. The method is well suited to take advantage of sparse matrix algebra to achieve linear scaling complexity in the computational cost as a function of system size for sufficiently large nonmetallic materials and metals at high temperatures.

  18. Plate tectonics conserves angular momentum

    NASA Astrophysics Data System (ADS)

    Bowin, C.

    2010-03-01

    A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4+27 kg m2 s-1). Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates). Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies revealed by geoid anomalies of the degree 4-10 packet of the Earth's spherical harmonic coefficients. These linear positive geoid anomalies underlie plate subduction zones and are presumed due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth). The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant

  19. Two-axis angular effector

    DOEpatents

    Vaughn, Mark R.; Robinett, III, Rush D.; Phelan, John R.; Van Zuiden, Don M.

    1997-01-21

    A new class of coplanar two-axis angular effectors. These effectors combine a two-axis rotational joint analogous to a Cardan joint with linear actuators in a manner to produce a wider range of rotational motion about both axes defined by the joint. This new class of effectors also allows design of robotic manipulators having very high strength and efficiency. These effectors are particularly suited for remote operation in unknown surroundings, because of their extraordinary versatility. An immediate application is to the problems which arise in nuclear waste remediation.

  20. Variable Distance Angular Symbology Reader

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F., Jr. (Inventor); Corder, Eric L. (Inventor)

    2006-01-01

    A variable distance angular symbology, reader utilizes at least one light source to direct light through a beam splitter and onto a target. A target may be angled relative to the impinging light beam up to and maybe even greater than 45deg. A reflected beam from the target passes through the beam splitter and is preferably directed 90deg relative to the light source through a telecentric lens to a scanner which records an image of the target such as a direct part marking code.

  1. A Herschel-PACS view of 16 Centaurs

    NASA Astrophysics Data System (ADS)

    Duffard, Rene; Pinilla-Alonso, N.; Santos-Sanz, P.; Vilenius, E.; Ortiz, J.; Mueller, T.; Fornasier, S.; Lellouch, E.; Mommert, M.; Pal, A.; Kiss, C.; Mueller, M.; Stansberry, J.; Delsanti, A.; Peixinho, N.

    2013-10-01

    The goal of this work is to characterize a set of Centaurs in terms of their size, albedo, and thermal properties. The Herschel open time key program "TNOs are Cool!'' observed 130 Centaurs and TNOs in 2009-2012. In this particular work we use Herschel/PACS three-band photometry to obtain monochromatic flux densities at 70, 100 and 160 μm. Additionally, we also incorporate Spitzer/MIPS flux densities at 24 and 70 μm when available. We use a consistent method for data reduction and aperture photometry to finally determine sizes and albedos of 16 Centaurs using radiometric techniques. We study the correlations between the size and albedo resulting from our models and other physical (i.e spectral slope) and orbital parameters using a more extended sample (obtained from literature). The final sample comprises 36 objects: 18 Centaurs observed with Herschel/PACS; 10 observed only with Spitzer and 8 SDOs. The first conclusion is that the albedo of the Centaurs is not determined by their orbit. Similarly we do not find any correlation between diameter and orbital parameters. We also find that most of the objects in our sample are dark (pv < 7%) and most of them are small (D < 120km). However, we do not find any correlation between albedo and diameter, in particular for the group of the small objects we can find albedo values homogeneously distributed from 4 - 15%. When it comes to correlation with the color of the objects, we find that the red objects are all small (mean diameter 65 km), while the gray ones are either small or large (mean diameter 120 km). Also, the gray objects seem to be darker, with a mean value of 5.6%, while for the red objects the albedo can vary from 5 to 15%, with a mean value of 8.5%. All of this shows that there are other physical properties (size and albedo distribution) that make differences between the gray and red objects, even if we do not yet have a physical explanation for the origin of this bimodality.

  2. Effect of PACS on patient radiation doses for examination of the lateral lumbar spine

    NASA Astrophysics Data System (ADS)

    Weatherburn, Gwyneth C.; Bryan, Stirling; Buxton, Martin J.

    1998-07-01

    The aim of the study described in this paper was to identify and measure any changes in radiation dose attributable to the implementation of the hospital wide Hammersmith PACS system. The authors believe this study to be a comprehensive study of changes in patient dose for the examination of the lateral lumbar spine associated with the introduction of PACS: the study has fully monitored the many factors which affect these patient doses. Some very optimistic claims of large dose reductions with the introduction PACS at other hospitals have been based upon minimal reported evidence, or comparisons have been made with very old high dose systems with film/screen sensitivities as low as 100. In this study the patient doses with the PACS system have been compared with those measured when a conventional film/screen system with a sensitivity of 300 was used.

  3. Radiology department design to accommodate the future introduction of global PACS.

    PubMed

    Naylor, A F

    1992-12-01

    In the light of the continuing development of pictorial archiving and communication systems (PACS) and image management and communications (IMAC) systems it is appropriate to consider the provision that should be made in the design of a new or renovated department of radiology to accommodate these new technologies at either an earlier or later date. This paper considers three particular aspects of the influence of PACS on future department design: (1) the requirement for either more or less total department gross square feet, (2) the provision for the specific allocation of spaces at certain locations for PACS equipment and functions, and (3) the provision for dedicated pathways for fiber optic communications among the many locations in the department where PACS components would be located. PMID:1490477

  4. 76 FR 41826 - State, Local, Tribal, and Private Sector Policy Advisory Committee (SLTPS-PAC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-15

    ... From the Federal Register Online via the Government Publishing Office NATIONAL ARCHIVES AND RECORDS ADMINISTRATION Information Security Oversight Office State, Local, Tribal, and Private Sector Policy Advisory Committee (SLTPS-PAC) AGENCY: National Archives and Records Administration....

  5. Play P.A.C. Game to Review Domains and Taxonomies of Educational Objectives.

    ERIC Educational Resources Information Center

    Holt, Barbara A.; Harrison, Betty C.

    1983-01-01

    The "P.A.C. Game" provides a creative way for preservice teachers to develop their understanding of taxonomies of objectives in the psychomotor, affective, and cognitive domains. The game also helps give teachers feedback about students' progress. (PP)

  6. A grid PACS architecture: providing data-centric applications through a grid infrastructure.

    PubMed

    Koutelakis, George V; Lymperopoulos, Dimitrios K

    2007-01-01

    The large growth of medical information and the needs for computing resources for processing of medical images in medical diagnosis procedures demand advanced network solutions in Picture Archiving and Communication Systems (PACS). Grid infrastructure is a new network generation that expands the collaborative environment which is created inside Internet. Grid can meet the above requirements effectively providing PACS with distribution of processing power, storage space and software applications. This paper proposes a new web PACS established in a Grid infrastructure of a Hospital Radiology Department (HRD). A portal platform based on reliable and tried in market products as well as Java-based applications support the implementation of the new Grid PACS architecture. PMID:18003494

  7. Perturbative construction of stationary Randall-Sundrum II black holes on a 5-brane

    NASA Astrophysics Data System (ADS)

    Stein, Maren

    2016-09-01

    We numerically construct large Randall-Sundrum II brane black holes in 4 and 5 dimensions from associated AdS/CFT spacetimes. Our solutions are leading order perturbations of a representative of the boundary conformal structure of the AdS spacetime sourced by the dual CFT stress tensor. The 4-dimensional solutions are static perturbations of the Euclidean Schwarzschild metric, while the 5-dimensional solutions are perturbations of the Myers-Perry metric with equal angular momenta. We compare the former with previous numerical results for Randall-Sundrum bulk black holes and find good agreement down to a horizon radius of about r H ˜ 30ℓ. The latter are the first numerical results pertaining to rotating Randall-Sundrum black holes. They have the same entropy, but a larger horizon area than Myers-Perry black holes of the same mass and angular momentum.

  8. On dark energy isocurvature perturbation

    SciTech Connect

    Liu, Jie; Zhang, Xinmin; Li, Mingzhe E-mail: limz@nju.edu.cn

    2011-06-01

    Determining the equation of state of dark energy with astronomical observations is crucially important to understand the nature of dark energy. In performing a likelihood analysis of the data, especially of the cosmic microwave background and large scale structure data the dark energy perturbations have to be taken into account both for theoretical consistency and for numerical accuracy. Usually, one assumes in the global fitting analysis that the dark energy perturbations are adiabatic. In this paper, we study the dark energy isocurvature perturbation analytically and discuss its implications for the cosmic microwave background radiation and large scale structure. Furthermore, with the current astronomical observational data and by employing Markov Chain Monte Carlo method, we perform a global analysis of cosmological parameters assuming general initial conditions for the dark energy perturbations. The results show that the dark energy isocurvature perturbations are very weakly constrained and that purely adiabatic initial conditions are consistent with the data.

  9. Perturbation theory in electron diffraction

    NASA Astrophysics Data System (ADS)

    Bakken, L. N.; Marthinsen, K.; Hoeier, R.

    1992-12-01

    The Bloch-wave approach is used for discussing multiple inelastic electron scattering and higher-order perturbation theory in inelastic high-energy electron diffraction. In contrast to previous work, the present work describes three-dimensional diffraction so that higher-order Laue zone (HOLZ) effects are incorporated. Absorption is included and eigenvalues and eigenvectors are calculated from a structure matrix with the inclusion of an absorptive potential. Centrosymmetric as well as non-centrosymmetric crystal structures are allowed. An iteration method with a defined generalized propagation function for solving the inelastic coupling equations is described. It is shown that a similar iteration method with the same propagation function can be used for obtaining higher-order perturbation terms for the wave-function when a perturbation is added to the crystal potential. Finally, perturbation theory by matrix calculations when a general perturbation is added to the structure matrix is considered.

  10. Modulated preheating and isocurvature perturbations

    SciTech Connect

    Enqvist, Kari; Rusak, Stanislav E-mail: stanislav.rusak@helsinki.fi

    2013-03-01

    We consider a model of preheating where the coupling of the inflaton to the preheat field is modulated by an additional scalar field which is light during inflation. We establish that such a model produces the observed curvature perturbation analogously to the modulated reheating scenario. The contribution of modulated preheating to the power spectrum and to non-Gaussianity can however be significantly larger compared to modulated perturbative reheating. We also consider the implications of the current constraints on isocurvature perturbations in case where the modulating field is responsible for cold dark matter. We find that existing bounds on CDM isocurvature perturbations imply that modulated preheating is unlikely to give a dominant contribution to the curvature perturbation and that the same bounds suggest important constraints on non-Gaussianity and the amount of primordial gravitational waves.

  11. HIPAA-compliant automatic monitoring system for RIS-integrated PACS operation

    NASA Astrophysics Data System (ADS)

    Jin, Jin; Zhang, Jianguo; Chen, Xiaomeng; Sun, Jianyong; Yang, Yuanyuan; Liang, Chenwen; Feng, Jie; Sheng, Liwei; Huang, H. K.

    2006-03-01

    As a governmental regulation, Health Insurance Portability and Accountability Act (HIPAA) was issued to protect the privacy of health information that identifies individuals who are living or deceased. HIPAA requires security services supporting implementation features: Access control; Audit controls; Authorization control; Data authentication; and Entity authentication. These controls, which proposed in HIPAA Security Standards, are Audit trails here. Audit trails can be used for surveillance purposes, to detect when interesting events might be happening that warrant further investigation. Or they can be used forensically, after the detection of a security breach, to determine what went wrong and who or what was at fault. In order to provide security control services and to achieve the high and continuous availability, we design the HIPAA-Compliant Automatic Monitoring System for RIS-Integrated PACS operation. The system consists of two parts: monitoring agents running in each PACS component computer and a Monitor Server running in a remote computer. Monitoring agents are deployed on all computer nodes in RIS-Integrated PACS system to collect the Audit trail messages defined by the Supplement 95 of the DICOM standard: Audit Trail Messages. Then the Monitor Server gathers all audit messages and processes them to provide security information in three levels: system resources, PACS/RIS applications, and users/patients data accessing. Now the RIS-Integrated PACS managers can monitor and control the entire RIS-Integrated PACS operation through web service provided by the Monitor Server. This paper presents the design of a HIPAA-compliant automatic monitoring system for RIS-Integrated PACS Operation, and gives the preliminary results performed by this monitoring system on a clinical RIS-integrated PACS.

  12. P.A.C. Planner's Workbook. E.S.E.A. Title I. Revised.

    ERIC Educational Resources Information Center

    Davis, Chuck

    This workbook provides information and guidelines for planning and operating Parent Advisory Councils (P.A.C.s) provided for under the Elementary and Secondary Education Act Title I. The first part of the workbook, which was prepared for P.A.C. planners in the Phoenix, Arizona, Union High School District, is a month-by-month guide to P.A.C.…

  13. Efficiency and effectiveness of an innovative RIS function for patient information reconciliation directly integrated with PACS.

    PubMed

    Nitrosi, Andrea; Bertolini, Marco; Notari, Pietro; Botti, Andrea; Ginocchi, Vladimiro; Tondelli, Giulio; Iori, Mauro; Pattacini, Pierpaolo

    2013-06-01

    In RIS-PACS systems, potential errors occurring during the execution of a radiologic examination can amplify the clinical risks of the patient during subsequent treatments, e.g., of oncologic patients or of those who must do additional treatments based on the initial diagnosis. In Reggio Emilia Province Diagnostic Imaging Department (REDID) we experienced different strategies to reduce clinical risks due to patient reconciliation errors. In 2010, we developed a procedure directly integrated in our RIS-PACS that uses Health Level 7 (HL7) standard messaging, which generates an overlay with the text "under investigation" on the images of the study to be corrected. All the healthcare staff is informed of the meaning of that overlay, and only the radiologist and the emergency services staff can consult these images on PACS. The elimination of image overlay and of any access limitation to PACS was triggered to confirm of the right correction made by RIS-PACS system administrator (SA). The RIS-PACS integrated tool described in this paper allows technologists and radiologists to efficiently highlight patient exam errors and to inform all the users to minimize the overall clinical risks, with a significant savings in costs. Over the years, we have observed a steady decrease in the percentage of reconciled studies. Error reconciliation requires an effective and efficient mechanism. The RIS-PACS integrated tool described in this paper enables technologists and radiologists to quickly and efficiently highlight patient exam errors and inform all the users. Next generation of RIS-PACS could be equipped with similar reconciliation tools. PMID:23224607

  14. Clinical evaluation of using semantic searching engine for radiological imaging services in RIS-integrated PACS

    NASA Astrophysics Data System (ADS)

    Ling, Tonghui; Zhang, Kai; Yang, Yuanyuan; Hua, Yanqing; Zhang, Jianguo

    2015-03-01

    We had designed a semantic searching engine (SSE) for radiological imaging to search both reports and images in RIS-integrated PACS environment. In this presentation, we present evaluation results of this SSE about how it impacting the radiologists' behaviors in reporting for different kinds of examinations, and how it improving the performance of retrieval and usage of historical images in RIS-integrated PACS.

  15. Efficiency and effectiveness of an innovative RIS function for patient information reconciliation directly integrated with PACS.

    PubMed

    Nitrosi, Andrea; Bertolini, Marco; Notari, Pietro; Botti, Andrea; Ginocchi, Vladimiro; Tondelli, Giulio; Iori, Mauro; Pattacini, Pierpaolo

    2013-06-01

    In RIS-PACS systems, potential errors occurring during the execution of a radiologic examination can amplify the clinical risks of the patient during subsequent treatments, e.g., of oncologic patients or of those who must do additional treatments based on the initial diagnosis. In Reggio Emilia Province Diagnostic Imaging Department (REDID) we experienced different strategies to reduce clinical risks due to patient reconciliation errors. In 2010, we developed a procedure directly integrated in our RIS-PACS that uses Health Level 7 (HL7) standard messaging, which generates an overlay with the text "under investigation" on the images of the study to be corrected. All the healthcare staff is informed of the meaning of that overlay, and only the radiologist and the emergency services staff can consult these images on PACS. The elimination of image overlay and of any access limitation to PACS was triggered to confirm of the right correction made by RIS-PACS system administrator (SA). The RIS-PACS integrated tool described in this paper allows technologists and radiologists to efficiently highlight patient exam errors and to inform all the users to minimize the overall clinical risks, with a significant savings in costs. Over the years, we have observed a steady decrease in the percentage of reconciled studies. Error reconciliation requires an effective and efficient mechanism. The RIS-PACS integrated tool described in this paper enables technologists and radiologists to quickly and efficiently highlight patient exam errors and inform all the users. Next generation of RIS-PACS could be equipped with similar reconciliation tools.

  16. Clinical Experience With A PACS Module In Pediatric Radiology: Clinical Viewpoint

    NASA Astrophysics Data System (ADS)

    Kangarloo, H.; Boechat, M. I.; Dietrich, R.; Hall, T.; Taira, R. K.; Mankovich, N. J.; Huang, H. K.

    1988-06-01

    A PACS module for Pediatric Radiology began routine clinical operation in March 1987. The system thus far has been used to conduct daily X-ray rounds as well as for fast patient reviews during all hours of the day. This paper describes the clinical operation of this system including patient registration, image acquisition, image management, and patient case reviews. A PACS system operator is responsible for the daily mainenance of the system. These responsibilities are outlined.

  17. Controlling neutron orbital angular momentum.

    PubMed

    Clark, Charles W; Barankov, Roman; Huber, Michael G; Arif, Muhammad; Cory, David G; Pushin, Dmitry A

    2015-09-24

    The quantized orbital angular momentum (OAM) of photons offers an additional degree of freedom and topological protection from noise. Photonic OAM states have therefore been exploited in various applications ranging from studies of quantum entanglement and quantum information science to imaging. The OAM states of electron beams have been shown to be similarly useful, for example in rotating nanoparticles and determining the chirality of crystals. However, although neutrons--as massive, penetrating and neutral particles--are important in materials characterization, quantum information and studies of the foundations of quantum mechanics, OAM control of neutrons has yet to be achieved. Here, we demonstrate OAM control of neutrons using macroscopic spiral phase plates that apply a 'twist' to an input neutron beam. The twisted neutron beams are analysed with neutron interferometry. Our techniques, applied to spatially incoherent beams, demonstrate both the addition of quantum angular momenta along the direction of propagation, effected by multiple spiral phase plates, and the conservation of topological charge with respect to uniform phase fluctuations. Neutron-based studies of quantum information science, the foundations of quantum mechanics, and scattering and imaging of magnetic, superconducting and chiral materials have until now been limited to three degrees of freedom: spin, path and energy. The optimization of OAM control, leading to well defined values of OAM, would provide an additional quantized degree of freedom for such studies.

  18. Haptic underestimation of angular extent.

    PubMed

    Lakatos, S; Marks, L E

    1998-01-01

    To what extent can individuals accurately estimate the angle between two surfaces through touch alone, and how does tactile judgment compare to visual judgment? Subjects' ability to estimate angle size for a variety of haptic and visual stimuli was examined in a series of nine experiments. Triangular wooden blocks and raised contour outlines comprising different angles and radii of curvature at the apex were used in experiments 1-4 and it was found that subjects consistently underestimated angular extent relative to visual baselines and that the degree of underestimation was inversely related to the actual size of the angle. Angle estimates also increased with increasing radius of curvature when actual angle size was held constant. In contrast, experiments 5-8 showed that subjects did not underestimate angular extent when asked to perform a haptic-visual match to a computerized visual image; this outcome suggests that visual input may 'recalibrate' the haptic system's internal metric for estimating angle. The basis of this cross-modal interaction was investigated in experiment 9 by varying the nature and extent of visual cues available in haptic estimation tasks. The addition of visual-spatial cues did not significantly reduce the magnitude of haptic underestimation. The experiments as a whole indicate that haptic underestimations of angle occur in a number of different stimulus contexts, but leave open the question of exactly what type of visual information may serve to recalibrate touch in this regard. PMID:10197190

  19. Superfine powdered activated carbon (S-PAC) coatings on microfiltration membranes: Effects of milling time on contaminant removal and flux.

    PubMed

    Amaral, Pauline; Partlan, Erin; Li, Mengfei; Lapolli, Flavio; Mefford, O Thompson; Karanfil, Tanju; Ladner, David A

    2016-09-01

    In microfiltration processes for drinking water treatment, one method of removing trace contaminants is to add powdered activated carbon (PAC). Recently, a version of PAC called superfine PAC (S-PAC) has been under development. S-PAC has a smaller particle size and thus faster adsorption kinetics than conventionally sized PAC. Membrane coating performance of various S-PAC samples was evaluated by measuring adsorption of atrazine, a model micropollutant. S-PACs were created in-house from PACs of three different materials: coal, wood, and coconut shell. Milling time was varied to produce S-PACs pulverized with different amounts of energy. These had different particles sizes, but other properties (e.g. oxygen content), also differed. In pure water the coal based S-PACs showed superior atrazine adsorption; all milled carbons had over 90% removal while the PAC had only 45% removal. With addition of calcium and/or NOM, removal rates decreased, but milled carbons still removed more atrazine than PAC. Oxygen content and specific external surface area (both of which increased with longer milling times) were the most significant predictors of atrazine removal. S-PAC coatings resulted in loss of filtration flux compared to an uncoated membrane and smaller particles caused more flux decline than larger particles; however, the data suggest that NOM fouling is still more of a concern than S-PAC fouling. The addition of calcium improved the flux, especially for the longer-milled carbons. Overall the data show that when milling S-PAC with different levels of energy there is a tradeoff: smaller particles adsorb contaminants better, but cause greater flux decline. Fortunately, an acceptable balance may be possible; for example, in these experiments the coal-based S-PAC after 30 min of milling achieved a fairly high atrazine removal (overall 80%) with a fairly low flux reduction (under 30%) even in the presence of NOM. This suggests that relatively short duration (low energy

  20. XDS-I Gateway Development for HIE Connectivity with Legacy PACS at Gil Hospital

    PubMed Central

    Simalango, Mikael Fernandus; Kim, Youngchul; Seo, Young Tae; Cho, Yong Kyun

    2013-01-01

    Objectives The ability to support healthcare document sharing is imperative in a health information exchange (HIE). Sharing imaging documents or images, however, can be challenging, especially when they are stored in a picture archiving and communication system (PACS) archive that does not support document sharing via standard HIE protocols. This research proposes a standard-compliant imaging gateway that enables connectivity between a legacy PACS and the entire HIE. Methods Investigation of the PACS solutions used at Gil Hospital was conducted. An imaging gateway application was then developed using a Java technology stack. Imaging document sharing capability enabled by the gateway was tested by integrating it into Gil Hospital's order communication system and its HIE infrastructure. Results The gateway can acquire radiology images from a PACS storage system, provide and register the images to Gil Hospital's HIE for document sharing purposes, and make the images retrievable by a cross-enterprise document sharing document viewer. Conclusions Development of an imaging gateway that mediates communication between a PACS and an HIE can be considered a viable option when the PACS does not support the standard protocol for cross-enterprise document sharing for imaging. Furthermore, the availability of common HIE standards expedites the development and integration of the imaging gateway with an HIE. PMID:24523994

  1. Preparation and adsorption performance of MnO2/PAC composite towards aqueous glyphosate.

    PubMed

    Cui, Hao; Li, Qin; Qian, Yan; Zhang, Qiu; Zhai, Jianping

    2012-09-01

    Glyphosate (N-phosphonomethylglycine (PMG)) is the organophosphate herbicide most widely used in the world, and industrial production of PMG generates large quantities of wastewater. A manganese dioxide-coated powdered activated carbon (MnO2/PAC) composite was synthesized and investigated for the adsorption of PMG from wastewater. The results of scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectrometry (EDAX) revealed that MnO2 was formed on the surface of the carbon during the modification process. Batch adsorption results showed that the optimal pH for glyphosate adsorption on MnO2/PAC was 3.0. In the range 0.01(-1) molL(-1), glyphosate removal by MnO2/PAC decreased with an increase in ionic strength. Among the coexistent anions, only phosphate showed significant inhibition of PMG removal due to competitive complexation. Batch studies revealed that MnO2/PAC could reach a maximum PMG adsorption capacity of 283 mg g(-1). The Langmuir equilibrium model was found to be suitable for describing PMG sorption, and kinetic studies revealed that adsorption followed second-order rate kinetics. It was also proved that the adsorbed PMG could be effectively desorbed from MnO2/PAC in 1.0 molL(-1) NaOH. All of these results implied that the MnO2/PAC composite may be used as an effective adsorbent for recycling PMG from wastewater. PMID:23240199

  2. Design of a test director's workstation for ROC studies in a PACS

    NASA Astrophysics Data System (ADS)

    Wilson, Dennis L.; Frank, Mark S.; Smith, Donald V.; Nyland, Burnette

    1994-05-01

    A Test Director's Workstation has been developed to collect radiological exams in a PACS for studies. While the efficacy of PACS systems is being accepted in the radiological community, there remain many questions about the performance of a PACS to be answered. Some of the answers can be supplied by studies comparing the performance of radiologists using the PACS under different circumstances. A workstation that is useful in collecting images from the PACS at Madigan Army Medical Center for studies has been developed. The workstation retrieves the exam from the PACS, writes the exam to a local optical disk for permanent retention, and collects information about the exam in a Test Director's master exam file. In the process of collecting the exam the patient identification is stripped from the images to preserve the patient's privacy. The identification of the patient is retained in the Test Director's master file in order to follow the progress of the patient and determine the `truth' of any diagnosis. The Test Director's Workstation completes its task by helping the test director organize selected exams for reader's disks and by setting up a reader's worklist of exams to be read.

  3. Using WWW and JAVA for image access and interactive viewing in an integrated PACS.

    PubMed

    Bellon, E; Wauters, J; Fernàndez-Bayó, J; Feron, M; Verstreken, K; Van Cleynenbreugel, J; Van den Bosch, B; Desmaret, M; Marchal, G; Suetens, P

    1997-01-01

    We start from the observations that (1) potential benefits from PACS can only be realized if PACS and HIS are integrated into a 'multimedia medical information system', and (2) that this also requires integration at the level of the user interface. The user interface should allow integrated interaction with information from different subsystems, of which PACS is one. However, in the real world, different information systems are constructed using different technologies. Moreover, radiological image viewing is a highly interactive task that puts a particular burden on the graphical user interface. We describe our experiences in applying technology emerging around the 'World Wide Web' (WWW) for interactive access to an integrated PACS/HIS. We illustrate the use of Web browsers to access new medical services, touch technologies for interactive access to HIS-PACS information, and emphasize the potential of JAVA applets. We argue that JAVA may become an important tool for providing highly interactive user interfaces to larger multimedia information systems. We discuss Web technology in the general context of HIS/PACS integration.

  4. Java-based PACS and reporting system for nuclear medicine

    NASA Astrophysics Data System (ADS)

    Slomka, Piotr J.; Elliott, Edward; Driedger, Albert A.

    2000-05-01

    In medical imaging practice, images and reports often need be reviewed and edited from many locations. We have designed and implemented a Java-based Remote Viewing and Reporting System (JaRRViS) for a nuclear medicine department, which is deployed as a web service, at the fraction of the cost dedicated PACS systems. The system can be extended to other imaging modalities. JaRRViS interfaces to the clinical patient databases of imaging workstations. Specialized nuclear medicine applets support interactive displays of data such as 3-D gated SPECT with all the necessary options such as cine, filtering, dynamic lookup tables, and reorientation. The reporting module is implemented as a separate applet using Java Foundation Classes (JFC) Swing Editor Kit and allows composition of multimedia reports after selection and annotation of appropriate images. The reports are stored on the server in the HTML format. JaRRViS uses Java Servlets for the preparation and storage of final reports. The http links to the reports or to the patient's raw images with applets can be obtained from JaRRViS by any Hospital Information System (HIS) via standard queries. Such links can be sent via e-mail or included as text fields in any HIS database, providing direct access to the patient reports and images via standard web browsers.

  5. Stereotactic multibeam radiation therapy system in a PACS environment

    NASA Astrophysics Data System (ADS)

    Fresne, Francoise; Le Gall, G.; Barillot, Christian; Gibaud, Bernard; Manens, Jean-Pierre; Toumoulin, Christine; Lemoine, Didier; Chenal, C.; Scarabin, Jean-Marie

    1991-05-01

    A Multibeam radiation therapy treatment is a non-invasive technique devoted to treat a lesion within the cerebral medium by focusing photon-beams on the same target from a high number of entrance points. We present here a computer assisted dosimetric planning procedure which includes: (1) an analysis module to define the target volume by using 2D and 3D displays, (2) a planing module to issue a treatment strategy including the dosimetric simulations and (3) a treatment module setting up the parameters to order the robotized treatment system (i.e. chair- framework, radiation unit machine). Another important feature of this system is its connection to the PACS system SIRENE settled in the University hospital of Rennes which makes possible the archiving and the communication of the multimodal images (CT, MRI, Angiography) used by this application. The corporate use of stereotactic methods and the multimodality imagery ensures spatial coherence and makes the target definition and the cognition of the structures environment more accurate. The dosimetric planning suited to the spatial reference (i.e. the stereotactic frame) guarantees an optimal distribution of the dose computed by an original 3D volumetric algorithm. The robotic approach of the treatment stage has consisted to design a computer driven chair-framework cluster to position the target volume at the radiation unit isocenter.

  6. ROTO PEEN Scalar and VAC-PAC{reg_sign} system

    SciTech Connect

    1998-02-01

    The Pentek, Inc., milling technology, comprising the ROTO PEEN Scaler and the VAC-PAC{reg_sign} waste collection system, is a fully developed and commercialized technology used to remove hazardous coatings from concrete and steel floors, walls, ceilings, and structural components. This report describes a demonstration of the Pentek, Inc., milling system to remove the paint coating from 650 ft{sup 2} of concrete flooring on the service floor of the Chicago Pile-5 (CP-5) Research Reactor. CP-5 is a heavy-water moderated and cooled, highly enriched, uranium-fueled thermal reactor designed to supply neutrons for research. The reactor had a thermal-power rating of 5 megawatts and was operated continuously for 25 years until its final shutdown in 1979. These 25 years of operation produced activation and contamination characteristics representative of other nuclear facilities within the Department of Energy (DOE) complex and the commercial nuclear sector. CP-5 contains many of the essential features of other DOE and commercial nuclear facilities and can be used safely as a demonstration facility for the evaluation of innovative technologies for the future D and D of much larger, more highly contaminated facilities.

  7. Ongoing evaluation of PACS in a clinical setting

    NASA Astrophysics Data System (ADS)

    Trefler, Martin; Russell, Edward

    1992-05-01

    The radiology department of Jackson Memorial Hospital processes 255,000 clinical examinations each year -- 65,000 of which are portable x rays. Film transportation and loss are major obstacles to the smooth operation of this department. To assist in the solution of these problems we have designed and begun the piecemeal installation of a clinical PACS. This system is based on a platform of IBM RISC/6000 computers and software developed by Genesys Corporation. The initial installation involved the digitization of the portable x rays from three ICUs. The images (in the form of a matrix of 2048 X 1648 pixels) are then entered into the network and can be viewed simultaneously in the radiology department and in the ICU. The second phase of installation, involving the images from two CT scanners and two MRI scanners is currently underway. We have evaluated the system from several standpoints. The first is user acceptance. The users are the radiologists who must make the diagnosis at the workstation and the referring physicians who need the diagnosis quickly but also require the image. The radiologists must be comfortable with their diagnosis based on the images presented at the two viewer workstation. This is compared to the use of a multiviewer which presents many radiographs simultaneously. The second parameter for evaluation involves the impact on patient care in terms of the time elapsed between the taking of the radiograph and the presentation to the physician of the image and the diagnosis.

  8. Elementary derivation of the perturbation equations of celestial mechanics

    NASA Technical Reports Server (NTRS)

    Burns, J. A.

    1976-01-01

    The equations of celestial mechanics that govern the temporal rates of change of orbital elements are completely derived using elementary dynamics and proceeding only from Newton's equation and its solution. Two orbital equations and the four most meaningful orbital elements - semimajor axis, eccentricity, inclination, and longitude of pericenter - are written in terms of the orbital energy (E) and angular momentum (H) per unit mass. The six resulting equations are differentiated with respect to time to see the effect on the orbital elements of small changes in E and H. The usual perturbation equations in terms of disturbing-force components are then derived by computing the manner in which perturbing forces change E and H. The results are applied in a qualitative discussion of the orbital evolution of particles in nonspherical gravitational fields, through atmospheres, and under the action of tides.

  9. Disformal transformation of cosmological perturbations

    NASA Astrophysics Data System (ADS)

    Minamitsuji, Masato

    2014-10-01

    We investigate the gauge-invariant cosmological perturbations in the gravity and matter frames in the general scalar-tensor theory where two frames are related by the disformal transformation. The gravity and matter frames are the extensions of the Einstein and Jordan frames in the scalar-tensor theory where two frames are related by the conformal transformation, respectively. First, it is shown that the curvature perturbation in the comoving gauge to the scalar field is disformally invariant as well as conformally invariant, which gives the predictions from the cosmological model where the scalar field is responsible both for inflation and cosmological perturbations. Second, in case that the disformally coupled matter sector also contributes to curvature perturbations, we derive the evolution equations of the curvature perturbation in the uniform matter energy density gauge from the energy (non)conservation in the matter sector, which are independent of the choice of the gravity sector. While in the matter frame the curvature perturbation in the uniform matter energy density gauge is conserved on superhorizon scales for the vanishing nonadiabatic pressure, in the gravity frame it is not conserved even if the nonadiabatic pressure vanishes. The formula relating two frames gives the amplitude of the curvature perturbation in the matter frame, once it is evaluated in the gravity frame.

  10. Coping with perturbations to a layout somersault in tumbling.

    PubMed

    King, M A; Yeadon, M R

    2003-07-01

    Tumbling is a dynamic movement requiring control of the linear and angular momenta generated during the approach and takeoff phases. Both of these phases are subject to some variability even when the gymnast is trying to perform a given movement repeatedly. This paper used a simulation model of tumbling takeoff to establish how well gymnasts can cope with perturbations of the approach and takeoff phases. A five segment planar simulation model with torque generators at each joint was developed to simulate tumbling takeoffs. The model was customised to an elite gymnast by determining subject specific inertia and torque parameters and a simulation was produced which closely matched a performance of a layout somersault by the gymnast. The performance of a layout somersault was found to be sensitive to the approach characteristics and the activation timings but relatively insensitive to the elasticity of the track and maximum muscle strength. Appropriate variation of the activation timings used during the takeoff phase was capable of coping with moderate perturbations of the approach characteristics. A model of aerial movement established that variation of body configuration in the flight phase was capable of adjusting for takeoff perturbations that would lead to rotation errors of up to 8%. Providing the errors in perceiving approach characteristics are less than 5% or 5 degrees and the errors in timing activations are less than 7ms, perturbations in the approach can be accommodated using adjustments during takeoff and flight. PMID:12757800

  11. Refining the pH response in A spergillus nidulans: a modulatory triad involving PacX, a novel zinc binuclear cluster protein

    PubMed Central

    Bussink, Henk‐Jan; Bignell, Elaine M.; Múnera‐Huertas, Tatiana; Lucena‐Agell, Daniel; Scazzocchio, Claudio; Espeso, Eduardo A.; Bertuzzi, Margherita; Rudnicka, Joanna; Negrete‐Urtasun, Susana; Peñas‐Parilla, Maria M.; Rainbow, Lynne; Peñalva, Miguel Á.; Arst, Herbert N.

    2015-01-01

    Summary The A spergillus nidulans PacC transcription factor mediates gene regulation in response to alkaline ambient pH which, signalled by the Pal pathway, results in the processing of PacC72 to PacC27 via PacC53. Here we investigate two levels at which the pH regulatory system is transcriptionally moderated by pH and identify and characterise a new component of the pH regulatory machinery, PacX. Transcript level analysis and overexpression studies demonstrate that repression of acid‐expressed pal F, specifying the Pal pathway arrestin, probably by PacC27 and/or PacC53, prevents an escalating alkaline pH response. Transcript analyses using a reporter and constitutively expressed pac C  trans‐alleles show that pac C preferential alkaline‐expression results from derepression by depletion of the acid‐prevalent PacC72 form. We additionally show that pac C repression requires PacX. pac X mutations suppress PacC processing recalcitrant mutations, in part, through derepressed PacC levels resulting in traces of PacC27 formed by pH‐independent proteolysis. pac X was cloned by impala transposon mutagenesis. PacX, with homologues within the Leotiomyceta, has an unusual structure with an amino‐terminal coiled‐coil and a carboxy‐terminal zinc binuclear cluster. pacX mutations indicate the importance of these regions. One mutation, an unprecedented finding in A . nidulans genetics, resulted from an insertion of an endogenous Fot1‐like transposon. PMID:26303777

  12. Oral candidiasis and angular cheilitis.

    PubMed

    Sharon, Victoria; Fazel, Nasim

    2010-01-01

    Candidiasis, an often encountered oral disease, has been increasing in frequency. Most commonly caused by the overgrowth of Candida albicans, oral candidiasis can be divided into several categories including acute and chronic forms, and angular cheilitis. Risk factors for the development of oral candidiasis include immunosuppression, wearing of dentures, pharmacotherapeutics, smoking, infancy and old age, endocrine dysfunction, and decreased salivation. Oral candidiasis may be asymptomatic. More frequently, however, it is physically uncomfortable, and the patient may complain of burning mouth, dysgeusia, dysphagia, anorexia, and weight loss, leading to nutritional deficiency and impaired quality of life. A plethora of antifungal treatments are available. The overall prognosis of oral candidiasis is good, and rarely is the condition life threatening with invasive or recalcitrant disease.

  13. The Angular Momentum of the Solar System

    NASA Astrophysics Data System (ADS)

    Cang, Rongquin; Guo, Jianpo; Hu, Juanxiu; He, Chaoquiong

    2016-05-01

    The angular momentum of the Solar System is a very important physical quantity to the formation and evolution of the Solar System. Previously, the spin angular momentum of the Sun and the orbital angular momentum of the Eight Giant Planets were only taken into consideration, when researchers calculated the angular momentum of the Solar System. Nowadays, it seems narrow and conservative. Using Eggleton's code, we calculate the rotational inertia of the Sun. Furthermore, we obtain that the spin angular momentum of the Sun is 1.8838 x 10^41 kg m^2 s^-1. Besides the spin angular momentum of the Sun and the orbital angular momentum of the Eight Giant Planets, we also account for the orbital angular momentum of the Asteroid Belt, the Kuiper Belt, the Oort Cloud, the Ninth Giant Planet and the Solar Companion. We obtain that the angular momentum of the whole Solar System is 3.3212 x 10^45 kg m^2 s^-1.

  14. Perturbations of the Black Hole-Torus System: Instabilities and QPOs

    NASA Astrophysics Data System (ADS)

    Donmez, Orhan

    2016-07-01

    The existence of the black hole (BH)-torus system has been given a considerable attention to explain the variability of X-ray and Gamma-ray (γ-ray) data. The perturbation of the black hole-torus system creates instabilities and some of these instabilities are responsible for a quasi-periodic oscillation. In this talk, we present the results from numerical simulation of the dynamical instability of a pressure-supported relativistic torus, rotating around the black hole with a constant specific angular momentum on a fixed space-time background, in case of perturbation. The types of instabilities and their amplitudes strongly depend on what kind of perturbation is applied. The types of perturbations can be a blob of hot gas, Bondi-Hoyle accretion from a finite distance, radial and angular velocity perturbations of the stable accreted torus, and non-spherical accretion as a consequence of isotropic fall of the spherical-shell which has finite thickness. We study the effects of perturbations onto the torus-black hole system by solving the hydrodynamical equations and we have found that the torus around the black hole would have an instability, which is called the Papaloizou-Pringle, and a quasi-periodic oscillation only if we choose a suitable perturbations and initial data. It is noted that, while the perturbations, which are called blob of hot gas, radial velocity perturbations and Bondi-Hoyle accretion, create the Papaloizou-Pringle instability, the Papaloizou-Pringle instability is softly developed and removed in a short time scale for spherical shell accretion. Our studies also indicate that QPOs are common phenomena on the disc around the black holes. If the accretion disc or torus has a quasi-periodic behavior, it emits continuous radiation during the oscillation.

  15. Gauge invariant perturbations of self-similar Lemaitre-Tolman-Bondi spacetime: Even parity modes with l{>=}2

    SciTech Connect

    Waters, Thomas J.; Nolan, Brien C.

    2009-04-15

    In this paper we consider gauge invariant linear perturbations of the metric and matter tensors describing the self-similar Lemaitre-Tolman-Bondi (timelike dust) spacetime containing a naked singularity. We decompose the angular part of the perturbation in terms of spherical harmonics and perform a Mellin transform to reduce the perturbation equations to a set of ordinary differential equations with singular points. We fix initial data so the perturbation is finite on the axis and the past null cone of the singularity, and follow the perturbation modes up to the Cauchy horizon. There we argue that certain scalars formed from the modes of the perturbation remain finite, indicating linear stability of the Cauchy horizon.

  16. Causal compensated perturbations in cosmology

    NASA Technical Reports Server (NTRS)

    Veeraraghavan, Shoba; Stebbins, Albert

    1990-01-01

    A theoretical framework is developed to calculate linear perturbations in the gravitational and matter fields which arise causally in response to the presence of stiff matter sources in a FRW cosmology. It is shown that, in order to satisfy energy and momentum conservation, the gravitational fields of the source must be compensated by perturbations in the matter and gravitational fields, and the role of such compensation in containing the initial inhomogeneities in their subsequent evolution is discussed. A complete formal solution is derived in terms of Green functions for the perturbations produced by an arbitrary source in a flat universe containing cold dark matter. Approximate Green function solutions are derived for the late-time density perturbations and late-time gravitational waves in a universe containing a radiation fluid. A cosmological energy-momentum pseudotensor is defined to clarify the nature of energy and momentum conservation in the expanding universe.

  17. Context indexing of digital cardiac ultrasound records in PACS

    NASA Astrophysics Data System (ADS)

    Lobodzinski, S. Suave; Meszaros, Georg N.

    1998-07-01

    Recent wide adoption of the DICOM 3.0 standard by ultrasound equipment vendors created a need for practical clinical implementations of cardiac imaging study visualization, management and archiving, DICOM 3.0 defines only a logical and physical format for exchanging image data (still images, video, patient and study demographics). All DICOM compliant imaging studies must presently be archived on a 650 Mb recordable compact disk. This is a severe limitation for ultrasound applications where studies of 3 to 10 minutes long are a common practice. In addition, DICOM digital echocardiography objects require physiological signal indexing, content segmentation and characterization. Since DICOM 3.0 is an interchange standard only, it does not define how to database composite video objects. The goal of this research was therefore to address the issues of efficient storage, retrieval and management of DICOM compliant cardiac video studies in a distributed PACS environment. Our Web based implementation has the advantage of accommodating both DICOM defined entity-relation modules (equipment data, patient data, video format, etc.) in standard relational database tables and digital indexed video with its attributes in an object relational database. Object relational data model facilitates content indexing of full motion cardiac imaging studies through bi-directional hyperlink generation that tie searchable video attributes and related objects to individual video frames in the temporal domain. Benefits realized from use of bi-directionally hyperlinked data models in an object relational database include: (1) real time video indexing during image acquisition, (2) random access and frame accurate instant playback of previously recorded full motion imaging data, and (3) time savings from faster and more accurate access to data through multiple navigation mechanisms such as multidimensional queries on an index, queries on a hyperlink attribute, free search and browsing.

  18. Mayo/IBM PACS project: phase zero description

    NASA Astrophysics Data System (ADS)

    Gehring, Dale G.; Salutz, James R.; Brooks, Everett G.; Rothman, Melvyn L.; Morin, Richard L.

    1990-08-01

    A demonstration picture archiving and comniunication system (PACS) was developed using standard networking protocols. The systera was developed primarily to gain experience in digital image communications and optical disk usage as well as to raeasure perforittance factors to be used in the design of a substantially larger system. The system consists of a General Electric SIGNA MRI system connected via Ethernet to an IBM P5/2 Model 70, which serves as a gateway to a token-ring network. Resident on the token-ring, along with the P5/2, is an IBM AS/400 computer, an IBM System/36 with an optical storage subsystem and an IBM PS/2-based image review work station. Custom software was developed on each of the computers to control the flow of data and to manage the storage and retrieval of images. Standard TCP/IP software (File Transfer Protocol) is used to transfer the images from the MRI system to the P5/2. The images are converted into ACR/NEMA file format and made available to the communication and archiving system. Under AS/400 control, P5/2 resident programs copy a subset of the ACR/NEMA header information to an AS/400 database, and copy all of the image files to the optical storage subsystem for permanent storage. AS/400 programs were developed to enable database query operations. User-selected images are transferred from the optical storage subsystem either back to the MRI system or to the P5/2-based image review work station.

  19. K2 and Herschel/PACS photometry of irregular satellites

    NASA Astrophysics Data System (ADS)

    Pal, Andras; Kiss, Csaba; Molnar, Laszlo; Mueller, Thomas G.; Sarneczky, Krisztian; Szabo, Robert; Kiss, Laszlo L.; Szabo, Gyula M.

    2016-10-01

    The combination of optical and far-infrared photometric measurements yields an unambiguous method for characterizing the basic physical and surface properties of minor bodies in the Solar System. In principle, an object with a certain visible brightness can either be an object with a small but bright or a large but dim surface. To resolve this issue, conducting thermal emission measurements can also be acquired since both larger and dimmer objects have higher infrared radiations. In addition, the precise modelling of thermal emission should certainly take into account the rotation period of these bodies - otherwise the presence of surface thermal inertia can result in inaccurate conclusions regarding to the physical size and albedo.Since early 2014, Kepler Space Telescope surveys fields close to the Ecliptic in a framework of quarterly campaigns of the K2 initiative. This program makes possible to continuously observe Solar System bodies during this period of 80-90 days and hence provide an uninterrupted photometric series of moving Solar System objects down to the magnitude range of R = 23.5. This instrument hence an ideal observatory now for Solar System studies. Due to the fact that the expected rotational periods of these objects are commensurable to the diurnal characteristics of ground-based observations, such uninterrupted light curves are rather valuable for the accurate determination of rotational characteristics - including the physical rotation period, the amplitude and the confirmation of the presence of double- or multiple peaked features.In this presentation we summarize our results of current K2 and legacy Herschel/PACS observations regarding to some of the irregular satellites of Uranus and Neptune, namely Caliban, Sycorax, Prospero, Setebos and Nereid. By comparing these results with similar kind of observations for trans-Neptunian objects (see Kiss et al., this DPS meeting), one can conclude how the formation and evolution of the outer Solar

  20. H-ATLAS: PACS imaging for the Science Demonstration Phase

    NASA Astrophysics Data System (ADS)

    Ibar, Edo; Ivison, R. J.; Cava, A.; Rodighiero, G.; Buttiglione, S.; Temi, P.; Frayer, D.; Fritz, J.; Leeuw, L.; Baes, M.; Rigby, E.; Verma, A.; Serjeant, S.; Müller, T.; Auld, R.; Dariush, A.; Dunne, L.; Eales, S.; Maddox, S.; Panuzzo, P.; Pascale, E.; Pohlen, M.; Smith, D.; de Zotti, G.; Vaccari, M.; Hopwood, R.; Cooray, A.; Burgarella, D.; Jarvis, M.

    2010-11-01

    We describe the reduction of data taken with the PACS instrument on board the Herschel Space Observatory in the Science Demonstration Phase of the Herschel-ATLAS (H-ATLAS) survey, specifically data obtained for a 4 × 4 deg2 region using Herschel's fast-scan (60arcsecs-1) parallel mode. We describe in detail a pipeline for data reduction using customized procedures within HIPE from data retrieval to the production of science-quality images. We found that the standard procedure for removing cosmic ray glitches also removed parts of bright sources and so implemented an effective two-stage process to minimize these problems. The pronounced 1/f noise is removed from the timelines using 3.4- and 2.5-arcmin boxcar high-pass filters at 100 and 160μm. Empirical measurements of the point spread function (PSF) are used to determine the encircled energy fraction as a function of aperture size. For the 100- and 160-μm bands, the effective PSFs are ~9 and ~13arcsec (FWHM), and the 90-per cent encircled energy radii are 13 and 18arcsec. Astrometric accuracy is good to <~2arcsec. The noise in the final maps is correlated between neighbouring pixels and rather higher than advertised prior to launch. For a pair of cross-scans, the 5σ point-source sensitivities are 125-165mJy for 9-13 arcsec radius apertures at 100μm and 150-240mJy for 13-18 arcsec radius apertures at 160μm.

  1. The design of a CORBA-based PACS in three-tier architecture

    NASA Astrophysics Data System (ADS)

    Li, Zhuo; Wu, Lingda; Wei, Yingmei; Xie, Hongwei

    2005-04-01

    In the past the most of the traditional PACS adopt two-tier Client/Server architecture based on DICOM network in china. However, with the developments of PACS that becomes more large-scale and distributed, the traditional PACS architecture has a lot of weaknesses. To overcome these shortcomings, this paper presents a CORBA-based PACS in three-tier architecture which consists of the application-tier, the middle-tier and the DICOM data-tier. In application-tier, the upper applications can use the service offered from the middle-tier through the application interface. In middle-tier, the characteristic service of PACS, which are extracted from the traditional PACS, are wrapped in service components plug in the ORB software bus. For the data exchange in CORBA-based implementation, the middleware uses IIOP to call service components through the ORB then to return the results to the application-tier. The CORBA object services are responsible for the object location, creation, implementation and destruction, etc. In DICOM data-tier, DICOM image modalities and DICOM databases provide DICOM data for the middle-tier through DICOM image access service. Furthermore, a design of DICOM image access service, which accesses DICOM data and shields the middle-tier from the complexities of DICOM data structure and DIMSE protocol, is presented in this paper. After referred to the CIAS (Clinical Image Access Service) specification defined by OMG, a simplified IDL interface of DICOM image access service is also described. The CORBA-based PACS architecture is an open architecture allowing for the scalability and the interconnectivity & interoperability.

  2. Regulation of genes encoding cellulolytic enzymes by Pal-PacC signaling in Aspergillus nidulans.

    PubMed

    Kunitake, Emi; Hagiwara, Daisuke; Miyamoto, Kentaro; Kanamaru, Kyoko; Kimura, Makoto; Kobayashi, Tetsuo

    2016-04-01

    Cellulosic biomass represents a valuable potential substitute for fossil-based fuels. As such, there is a strong need to develop efficient biotechnological processes for the enzymatic hydrolysis of cellulosic biomass via the optimization of cellulase production by fungi. Ambient pH is an important factor affecting the industrial production of cellulase. In the present study, we demonstrate that several Aspergillus nidulans genes encoding cellulolytic enzymes are regulated by Pal-PacC-mediated pH signaling, as evidenced by the decreased cellulase productivity of the palC mutant and pacC deletants of A. nidulans. The deletion of pacC was observed to result in delayed induction and decreased expression of the cellulase genes based on time course expression analysis. The genome-wide identification of PacC-regulated genes under cellobiose-induced conditions demonstrated that genes expressed in a PacC-dependent manner included 82 % of ClrB (a transcriptional activator of the cellulase genes)-regulated genes, including orthologs of various transporter and β-glucosidase genes considered to be involved in cellobiose uptake or production of stronger inducer molecules. Together with the significant overlap between ClrB- and PacC-regulated genes, the results suggest that PacC-mediated regulation of the cellulase genes involves not only direct regulation by binding to their promoter regions but also indirect regulation via modulation of the expression of genes involved in ClrB-dependent transcriptional activation. Our findings are expected to contribute to the development of more efficient industrial cellulase production methods.

  3. Removal of persistent pharmaceutical micropollutants from sewage by addition of PAC in a sequential membrane bioreactor.

    PubMed

    Serrano, D; Suárez, S; Lema, J M; Omil, F

    2011-10-15

    The performance of a membrane bioreactor operating in a sequential mode (SMBR) using an external flat-plate membrane was investigated. After 200 days of operation, a single addition of 1 g L(-1) Powdered Activated Carbon (PAC) was added directly into the mixed liquor in order to enhance the simultaneous removal of nutrients and pharmaceutical micropollutants from synthetic urban wastewater. Throughout the entire operation (288 days), Chemical Oxygen Demand (COD) removal efficiencies were up to 95%, ammonium nitrogen removal was maintained over 70-80%, whereas phosphorus removal achieved only high values (around 80%) after PAC addition. During the operation of the SMBR without PAC addition, micropollutants which exerted a more recalcitrant behaviour were carbamazepine, diazepam, diclofenac and trimethoprim, with no significant removal. On the other hand, moderate removals (42-64%) were observed for naproxen and erythromycin, whereas ibuprofen, roxithromycin and fluoxetine were removed in the range of 71-97%. The addition of PAC into the aeration tank was a successful tool to improve the removal of the more recalcitrant compounds up to 85%. The highest removal with PAC was observed for carbamazepine, trimethoprim as well as for roxithromycin, erythromycin and fluoxetine. The latter four compounds have amine groups and pKa in the range 6.7-10.1, thus the interaction between PAC and the positively charged amino groups might be the cause of their comparatively better results. Microbial ecology present in the biomass showed a higher abundance of Accumulibacter phosphatis as well as the ammonium oxidizing bacteria belonging to the genus Nitrosomonas after PAC addition. PMID:21864878

  4. Transverse and longitudinal angular momenta of light

    NASA Astrophysics Data System (ADS)

    Bliokh, Konstantin Y.; Nori, Franco

    2015-08-01

    We review basic physics and novel types of optical angular momentum. We start with a theoretical overview of momentum and angular momentum properties of generic optical fields, and discuss methods for their experimental measurements. In particular, we describe the well-known longitudinal (i.e., aligned with the mean momentum) spin and orbital angular momenta in polarized vortex beams. Then, we focus on the transverse (i.e., orthogonal to the mean momentum) spin and orbital angular momenta, which were recently actively discussed in theory and observed in experiments. First, the recently-discovered transverse spin angular momenta appear in various structured fields: evanescent waves, interference fields, and focused beams. We show that there are several kinds of transverse spin angular momentum, which differ strongly in their origins and physical properties. We describe extraordinary features of the transverse optical spins and overview recent experiments. In particular, the helicity-independent transverse spin inherent in edge evanescent waves offers robust spin-direction coupling at optical interfaces (the quantum spin Hall effect of light). Second, we overview the transverse orbital angular momenta of light, which can be both extrinsic and intrinsic. These two types of the transverse orbital angular momentum are produced by spatial shifts of the optical beams (e.g., in the spin Hall effect of light) and their Lorentz boosts, respectively. Our review is underpinned by a unified theory of the angular momentum of light based on the canonical momentum and spin densities, which avoids complications associated with the separation of spin and orbital angular momenta in the Poynting picture. It allows us to construct a comprehensive classification of all known optical angular momenta based on their key parameters and main physical properties.

  5. Angular Momentum Eigenstates for Equivalent Electrons.

    ERIC Educational Resources Information Center

    Tuttle, E. R.; Calvert, J. B.

    1981-01-01

    Simple and efficient methods for adding angular momenta and for finding angular momentum eigenstates for systems of equivalent electrons are developed. Several different common representations are used in specific examples. The material is suitable for a graduate course in quantum mechanics. (SK)

  6. Angular-Rate Estimation Using Quaternion Measurements

    NASA Technical Reports Server (NTRS)

    Azor, Ruth; Bar-Itzhack, Y.; Deutschmann, Julie K.; Harman, Richard R.

    1998-01-01

    In most spacecraft (SC) there is a need to know the SC angular rate. Precise angular rate is required for attitude determination, and a coarse rate is needed for attitude control damping. Classically, angular rate information is obtained from gyro measurements. These days, there is a tendency to build smaller, lighter and cheaper SC, therefore the inclination now is to do away with gyros and use other means and methods to determine the angular rate. The latter is also needed even in gyro equipped satellites when performing high rate maneuvers whose angular-rate is out of range of the on board gyros or in case of gyro failure. There are several ways to obtain the angular rate in a gyro-less SC. When the attitude is known, one can differentiate the attitude in whatever parameters it is given and use the kinematics equation that connects the derivative of the attitude with the satellite angular-rate and compute the latter. Since SC usually utilize vector measurements for attitude determination, the differentiation of the attitude introduces a considerable noise component in the computed angular-rate vector.

  7. Strengthening your ties to referring physicians through RIS/PACS integration.

    PubMed

    Worthy, Susan; Rounds, Karla C; Soloway, Connie B

    2003-01-01

    Many imaging centers are turning to technology solutions to increase refering physician satisfaction, implementing such enhancements as automated report distribution, picture archiving and communications system (PACS), radiology information systems (RIS), and web-based results access. However, without seamless integration, these technology investments don't address the challenge at its core: convenient and reliable, two-way communication and interaction with referring physicians. In an integrated RIS/PACS solution, patient tracking in the RIS and PACS study status are logged and available to users. The time of the patient's registration at the imaging center, the exam start and completion time, the patient's departure time from the imaging center, and results status are all tracked and logged. An integrated RIS/PACS solution provides additional support to the radiologist, a critical factor that can improve the turnaround time of results to referring physicians. The RIS/PACS enhances the interpretation by providing the patient's history, which gives the radiologist additional insight and decreases the likelihood of missing a diagnostic element. In a tightly integrated RIS/PACS solution, results information is more complete. Physicians can view reports with associated images selected by the radiologist. They will also have full order information and complete imaging history including prior reports and images. Referring physicians can access and view images and exam notes at the same time that the radiologist is interpreting the exam. Without the benefit of an integrated RIS/PACS system, the referring physician would have to wait for the signed transcription to be released. In a seamlessly integrated solution, film-tracking modules within the RIS are fused with digital imaging workflow in the PACS. Users can see at a glance if a historical exam is available on film and benefit when a complete study history--both film-based and digital--is presented with the current

  8. Strengthening your ties to referring physicians through RIS/PACS integration.

    PubMed

    Worthy, Susan; Rounds, Karla C; Soloway, Connie B

    2003-01-01

    Many imaging centers are turning to technology solutions to increase refering physician satisfaction, implementing such enhancements as automated report distribution, picture archiving and communications system (PACS), radiology information systems (RIS), and web-based results access. However, without seamless integration, these technology investments don't address the challenge at its core: convenient and reliable, two-way communication and interaction with referring physicians. In an integrated RIS/PACS solution, patient tracking in the RIS and PACS study status are logged and available to users. The time of the patient's registration at the imaging center, the exam start and completion time, the patient's departure time from the imaging center, and results status are all tracked and logged. An integrated RIS/PACS solution provides additional support to the radiologist, a critical factor that can improve the turnaround time of results to referring physicians. The RIS/PACS enhances the interpretation by providing the patient's history, which gives the radiologist additional insight and decreases the likelihood of missing a diagnostic element. In a tightly integrated RIS/PACS solution, results information is more complete. Physicians can view reports with associated images selected by the radiologist. They will also have full order information and complete imaging history including prior reports and images. Referring physicians can access and view images and exam notes at the same time that the radiologist is interpreting the exam. Without the benefit of an integrated RIS/PACS system, the referring physician would have to wait for the signed transcription to be released. In a seamlessly integrated solution, film-tracking modules within the RIS are fused with digital imaging workflow in the PACS. Users can see at a glance if a historical exam is available on film and benefit when a complete study history--both film-based and digital--is presented with the current

  9. Orbital angular momentum in optical fibers

    NASA Astrophysics Data System (ADS)

    Bozinovic, Nenad

    Internet data traffic capacity is rapidly reaching limits imposed by nonlinear effects of single mode fibers currently used in optical communications. Having almost exhausted available degrees of freedom to orthogonally multiplex data in optical fibers, researchers are now exploring the possibility of using the spatial dimension of fibers, via multicore and multimode fibers, to address the forthcoming capacity crunch. While multicore fibers require complex manufacturing, conventional multi-mode fibers suffer from mode coupling, caused by random perturbations in fibers and modal (de)multiplexers. Methods that have been developed to address the problem of mode coupling so far, have been dependent on computationally intensive digital signal processing algorithms using adaptive optics feedback or complex multiple-input multiple-output algorithms. Here we study the possibility of using the orbital angular momentum (OAM), or helicity, of light, as a means of increasing capacity of future optical fiber communication links. We first introduce a class of specialty fibers designed to minimize mode coupling and show their potential for OAM mode generation in fibers using numerical analysis. We then experimentally confirm the existence of OAM states in these fibers using methods based on fiber gratings and spatial light modulators. In order to quantify the purity of created OAM states, we developed two methods based on mode-image analysis, showing purity of OAM states to be 90% after 1km in these fibers. Finally, in order to demonstrate data transmission using OAM states, we developed a 4-mode multiplexing and demultiplexing systems based on free-space optics and spatial light modulators. Using simple coherent detection methods, we successfully transmit data at 400Gbit/s using four OAM modes at a single wavelength, over 1.1 km of fiber. Furthermore, we achieve data transmission at 1.6Tbit/s using 10 wavelengths and two OAM modes. Our study indicates that OAM light can exist

  10. Design and performance evaluation of web-based medical image display system for PACS applications

    NASA Astrophysics Data System (ADS)

    Sun, Jianyong; Zhang, Jianguo; Huang, Yongbin; Tang, Shan; Huang, H. K.

    2003-05-01

    During the past several years, the using the Web technology and Web server as a means to access PACS image data are being considered and implemented with different technologies architectures. Here, we presented our design and implementation about developing component-based image display module, and then, gave a method to integrate this image display processing (DP) component into a Web-based image distribution server to enable users using Web browsers to access, view and manipulate PACS images. First, we designed the component software architecture of the image display. Second, we developed a Web-based PACS image distribution server based on component architecture, and integrated the DP components and other three PACS components into the Web architecture. Third, we added the new interface supporting http communication to the DP component by using the WinINet API (application program interface) developed by Microsoft, so that, the DP component can be plug-in to Web browsers to interact with the component-based Web server to display and manipulate DICOM images sent from any PACS archiving server. The performance evaluation on the diagnostic display workstation and the component-based Web server shows that the image distribution and display performance from the Web server to browser clients is similar with that of the image loading and displaying procedure of the diagnostic workstation, as more browser clients accessing to the Web server at same time.

  11. Engineering and clinical-oriented solution to cost-effective PACS for developing areas in China

    NASA Astrophysics Data System (ADS)

    Hu, Dake; Zhang, Hong; Zhou, Shengmin; Shao, Lin

    1997-05-01

    Although PACS has been studied in industrial countries for more than sixteen years, few effort has been made so far to apply PACS technology to such developing areas as most rural regions in CHina. Engineering and clinical problems raised from installing PACS in undeveloped areas has brought many challenges to our system design. In this study, we try to analyze the clinical need of the Chinese hospitals and find out a solution to meet most hospitals' requirements from engineering and clinical points of view, such as system cost, ease of deployment, user interface, maintenance difficulty, etc., thus provide patients with better medical serve at affordable cost. First of all, we analyzed data collected from Zhejiang Cancer Hospital (ZCH) and take hospitals' financial situation into consideration. then according to the analysis, we made our choices for hardware and software platform, digitizer and storage device. The development of mini PACS is interacted by clinicians and radiologists from ZCH. They showed great interest in the downsizing PACS that does not risk much of the system performance. It is promising that our solution will be accepted in developing areas.

  12. Effect of PAC addition on immersed ultrafiltration for the treatment of algal-rich water.

    PubMed

    Zhang, Yan; Tian, Jiayu; Nan, Jun; Gao, ShanShan; Liang, Heng; Wang, Meilian; Li, Guibai

    2011-02-28

    The aim of this study was to evaluate the effect of powdered activated carbon (PAC) addition on the treatment of algal-rich water by immersed ultrafiltration (UF), in terms of permeate quality and membrane fouling. Experiments were performed with a hollow-fiber polyvinyl chloride ultrafiltration membrane at a laboratory scale, 20-25°C and 10 L/(m(2) h) constant permeate flux. UF could achieve an absolute removal of Microcystis aeruginosa cells, but a poor removal of algogenic organic matter (AOM) released into water, contaminants responsible for severe membrane fouling. The addition of 4 g/L PAC to the immersed UF reactor significantly alleviated the development of trans-membrane pressure and enhanced the removal of dissovled organic carbon (by 10.9±1.7%), UV(254) (by 27.1±1.7%), and microcystins (expressed as MC-LR(eq), by 40.8±4.2%). However, PAC had little effect on the rejection of hydrophilic high molecular weight AOM such as carbohydrates and proteins. It was also identified that PAC reduced the concentrations of carbohydrates and proteins in the reactor due to decreased light intensity, as well as the MC-LR(eq) concentration by PAC adsorption. PMID:21216530

  13. Reverse osmosis concentrate treatment via a PAC-MF accumulative countercurrent adsorption process.

    PubMed

    Zhao, Chunxia; Gu, Ping; Cui, Hangyu; Zhang, Guanghui

    2012-01-01

    Organic pollutants in reverse osmosis (RO) concentrates from wastewater reclamation are mainly comprised of low molecular weight biorefractory compounds. Generally, advanced oxidation methods for oxidizing these organics require a relatively high level of energy consumption. In addition, conventional adsorption removal methods require a large dose of activated carbon. However, the dose can be reduced if its full adsorption capacity can be used. Therefore, the combined technology of powdered activated carbon (PAC) adsorption and microfiltration (MF) membrane filtration was studied to develop a countercurrent two-stage adsorption process. A PAC accumulative adsorption prediction method was proposed based on the verification of a PAC multi-stage adsorption capacity equation. Moreover, the prediction method was amended for a more accurate prediction of the effluent quality because adsorption isotherm constants were affected by the initial adsorbate concentration. The required PAC dose for the accumulative countercurrent two-stage adsorption system was 0.6 g/L, whereas that of the conventional adsorption process was 1.05 g/L when the dilution factor(F) was 0.1 and the COD and DOC removal rates were set to 70% and 68.1%, respectively. Organic pollutants were satisfactorily removed with less consumption of PAC. Effluent from this combined technology can be further reclaimed by an RO process to improve the overall recovery rate to between 91.0% and 93.8% with both economic and environmental benefits. PMID:22082527

  14. Incremental cost of a department-wide PACS/CR implementation

    NASA Astrophysics Data System (ADS)

    Pratt, Hugh M.; Langlotz, Curtis P.; Feingold, Eric R.; Schwartz, J. Sanford; Kundel, Harold L.

    1997-05-01

    Incremental costs are determined for a department-wide implementation of picture archiving and communication systems and computed radiography (PACS/CR). This analysis involves determination of all capital and operational costs associated with PACS implementation over an eight-year time horizon. Economic effects are identified, adjusted for time value, and used to calculate Net Present Values (NPV) for each section of the Department of Radiology and for the department as a whole. NPV indicates the full economic impact of a project. Results indicate that a full PACS/CR implementation would not be cost-saving for a large, subspecialized department.However, the cost-savings produced when CR is removed from the analysis indicates that PACS implementation will produce a positive economic impact for departments which have CR already implemented or are committed to CR implementation. Departments that predominantly produce digital images should experience a greater economic savings from using PACS. Furthermore, lossy long-term archive compression rates of 10:1 or greater also produce cost-savings versus conventional imaging equipment.

  15. Reverse osmosis concentrate treatment via a PAC-MF accumulative countercurrent adsorption process.

    PubMed

    Zhao, Chunxia; Gu, Ping; Cui, Hangyu; Zhang, Guanghui

    2012-01-01

    Organic pollutants in reverse osmosis (RO) concentrates from wastewater reclamation are mainly comprised of low molecular weight biorefractory compounds. Generally, advanced oxidation methods for oxidizing these organics require a relatively high level of energy consumption. In addition, conventional adsorption removal methods require a large dose of activated carbon. However, the dose can be reduced if its full adsorption capacity can be used. Therefore, the combined technology of powdered activated carbon (PAC) adsorption and microfiltration (MF) membrane filtration was studied to develop a countercurrent two-stage adsorption process. A PAC accumulative adsorption prediction method was proposed based on the verification of a PAC multi-stage adsorption capacity equation. Moreover, the prediction method was amended for a more accurate prediction of the effluent quality because adsorption isotherm constants were affected by the initial adsorbate concentration. The required PAC dose for the accumulative countercurrent two-stage adsorption system was 0.6 g/L, whereas that of the conventional adsorption process was 1.05 g/L when the dilution factor(F) was 0.1 and the COD and DOC removal rates were set to 70% and 68.1%, respectively. Organic pollutants were satisfactorily removed with less consumption of PAC. Effluent from this combined technology can be further reclaimed by an RO process to improve the overall recovery rate to between 91.0% and 93.8% with both economic and environmental benefits.

  16. PAC1, a pH-Regulatory Gene from Fusarium verticillioides†

    PubMed Central

    Flaherty, Joseph E.; Pirttilä, Anna Maria; Bluhm, Burton H.; Woloshuk, Charles P.

    2003-01-01

    Fumonisins are a group of mycotoxins that contaminate maize and cause leukoencephalomalacia in equine, pulmonary edema in swine, and promote cancer in mice. Fumonisin biosynthesis in Fusarium verticillioides is repressed by nitrogen and alkaline pH. We cloned a PACC-like gene (PAC1) from F. verticillioides. PACC genes encode the major transcriptional regulators of several pH-responsive pathways in other filamentous fungi. In Northern blot analyses, a PAC1 probe hybridized to a 2.2-kb transcript present in F. verticillioides grown at alkaline pH. A mutant of F. verticillioides with a disrupted PAC1 gene had severely impaired growth at alkaline pH. The mutant produced more fumonisin than the wild type when grown on maize kernels and in a synthetic medium buffered at an acidic pH, 4.5. The mutant, but not the wild type, also produced fumonisin B1 when mycelia were resuspended in medium buffered at an alkaline pH, 8.4. Transcription of FUM1, a gene involved in fumonisin biosynthesis, was correlated with fumonisin production. We conclude that PAC1 is required for growth at alkaline pH and that Pac1 may have a role as a repressor of fumonisin biosynthesis under alkaline conditions. PMID:12957906

  17. Phased development of a web-based PACS viewer

    NASA Astrophysics Data System (ADS)

    Gidron, Yoad; Shani, Uri; Shifrin, Mark

    2000-05-01

    The Web browser is an excellent environment for the rapid development of an effective and inexpensive PACS viewer. In this paper we will share our experience in developing a browser-based viewer, from the inception and prototype stages to its current state of maturity. There are many operational advantages to a browser-based viewer, even when native viewers already exist in the system (with multiple and/or high resolution screens): (1) It can be used on existing personal workstations throughout the hospital. (2) It is easy to make the service available from physician's homes. (3) The viewer is extremely portable and platform independent. There is a wide variety of means available for implementing the browser- based viewer. Each file sent to the client by the server can perform some end-user or client/server interaction. These means range from HTML (for HyperText Markup Language) files, through Java Script, to Java applets. Some data types may also invoke plug-in code in the client, although this would reduce the portability of the viewer, it would provide the needed efficiency in critical places. On the server side the range of means is also very rich: (1) A set of files: html, Java Script, Java applets, etc. (2) Extensions of the server via cgi-bin programs, (3) Extensions of the server via servlets, (4) Any other helper application residing and working with the server to access the DICOM archive. The viewer architecture consists of two basic parts: The first part performs query and navigation through the DICOM archive image folders. The second part does the image access and display. While the first part deals with low data traffic, it involves many database transactions. The second part is simple as far as access transactions are concerned, but requires much more data traffic and display functions. Our web-based viewer has gone through three development stages characterized by the complexity of the means and tools employed on both client and server sides.

  18. Base case and perturbation scenarios

    SciTech Connect

    Edmunds, T

    1998-10-01

    This report describes fourteen energy factors that could affect electricity markets in the future (demand, process, source mix, etc.). These fourteen factors are believed to have the most influence on the State's energy environment. A base case, or most probable, characterization is given for each of these fourteen factors over a twenty year time horizon. The base case characterization is derived from quantitative and qualitative information provided by State of California government agencies, where possible. Federal government databases are nsed where needed to supplement the California data. It is envisioned that a initial selection of issue areas will be based upon an evaluation of them under base case conditions. For most of the fourteen factors, the report identities possible perturbations from base case values or assumptions that may be used to construct additional scenarios. Only those perturbations that are plausible and would have a significant effect on energy markets are included in the table. The fourteen factors and potential perturbations of the factors are listed in Table 1.1. These perturbations can be combined to generate internally consist.ent. combinations of perturbations relative to the base case. For example, a low natural gas price perturbation should be combined with a high natural gas demand perturbation. The factor perturbations are based upon alternative quantitative forecasts provided by other institutions (the Department of Energy - Energy Information Administration in some cases), changes in assumptions that drive the quantitative forecasts, or changes in assumptions about the structure of the California energy markets. The perturbations are intended to be used for a qualitative reexamination of issue areas after an initial evaluation under the base case. The perturbation information would be used as a "tiebreaker;" to make decisions regarding those issue areas that were marginally accepted or rejected under the base case. Hf a

  19. Identification of perturbation modes and controversies in ekpyrotic perturbations

    NASA Astrophysics Data System (ADS)

    Hwang, Jai-Chan; Noh, Hyerim

    2002-10-01

    If the linear perturbation theory is valid through the bounce, the surviving fluctuations from the ekpyrotic scenario (cyclic one as well) should have very blue spectra with suppressed amplitude for the scalar-type structure. We derive the same (and consistent) result using the curvature perturbation in the uniform-field (comoving) gauge and in the zero-shear gauge. Previously, Khoury et al. interpreted results from the latter gauge condition incorrectly and claimed the scale-invariant spectrum, thus generating controversy in the literature. We also correct similar errors in the literature based on wrong mode identification and joining condition. No joining condition is needed for the derivation.

  20. An investigation of vortical flowfields due to single and multiple surface perturbations at the forebody

    NASA Astrophysics Data System (ADS)

    Hamilton, Howard Hugh

    Vortical flowfields produced by one and two cylindrical surface perturbations at the apex of a blunted conical forebody were investigated as a function of geometric parameters that defined the perturbation: axial position, perturbation height, and circumferential position. Static side force and yaw moment measurements, smoke- and oil-flow visualizations and flowfield mappings were used to correlate changes in the flow physics with the aerodynamic loads. The flow physics at the perturbation were dominated by the presence of a horseshoe vortex at the base of the surface perturbation and three-dimensional wake shedding along its height. These phenomena created a region of high Reynolds shear stresses and fluctuation velocities that deformed locally the separation and reattachment lines and increased the strength of the secondary vortex. Nonlinear regressions of the aerodynamic loads as a function of the geometric parameters revealed a fractional power-law dependence of the decay rate of the loads on the perturbation height and a stronger power-law dependence of the growth rate on the axial position. A discrete vortex simulation of the flowfield in which the effect of the perturbations was simulated as a shift in shed vortex particles confirmed these dependencies. A pair of perturbations of equal height located at the same axial position but on opposite sides of the forebody manipulated the separation lines and the related vortices independently of each other. Perturbations placed on the same side of the forebody created flowfields that were dependent of the angular spacing between the pair and the circumferential position of the perturbations. It was concluded that although the presence of single and multiple surface perturbations was sufficient to deform the local surface skin-friction lines, they were not sufficient to change the global topological structure of the mean skin-friction patterns. This change in the topological structure is postulated to be sufficient

  1. Study of Radiologic Technologists' Perceptions of Picture Archiving and Communication System (PACS) Competence and Educational Issues in Western Australia.

    PubMed

    Floyd, Daniel M; Trepp, Errol R; Ipaki, Maryam; Ng, Curtise K C

    2015-06-01

    Although the implementation of picture archiving and communication system (PACS) could increase productivity of radiology departments, this depends on factors such as the PACS competence of radiologic technologists (RTs). The purpose of this study was to investigate the RTs' perceptions of PACS competence and educational issues in Western Australia (WA). A hardcopy questionnaire was distributed to WA RTs for obtaining their perceptions of PACS competence and educational issues. Descriptive (percentage of frequency, mean and standard deviation) and inferential statistics (t test and analysis of variance) were used to analyze the responses of the multiple choice and five-point scale questions from the returned questionnaires. The questionnaire response rate was 57.7% (173 out of 300). The mean values of all PACS competence questions except questions 2e-g are in the range of 3.9-4.9, i.e., around competent to very competent. Participants indicated they received adequate PACS training (mean 3.8). Statistically significant variables influencing RTs' perceptions of their PACS competence and educational issues including the age (p < 0.01), gender (p < 0.05), years of practice (p < 0.005-0.05), primary duty (p < 0.05), medical imaging qualification (p < 0.001), general computer skills (p < 0.001), and type of PACS education received (p < 0.001-0.05). The WA RTs indicated that they were competent in using the modality workstation, PACS and radiology information system, and received adequate training. However, future PACS education programs should be tailored to different RTs' groups. For example, multiple training modules might be necessary to support the PACS competence development of older RTs and those with lower general computer literacy.

  2. Effects of angular correlations on particle-particle propagation in infinite nuclear matter

    NASA Astrophysics Data System (ADS)

    Romero-Barrientos, J.; Arellano, H. F.

    2016-05-01

    The effect of angular correlations on self-consistent solutions for single-particle (sp) potentials in infinite nuclear matter is investigated. To this end we treat explicitly the angular dependence of the particle-particle (pp) propagator in Brueckner-Hartree-Fock (BHF) equation for the g matrix. It is observed that the exact angular dependence of the pp propagator yields highly fluctuating structures, posing stringent difficulties in the actual search of self-consistent solutions for the sp energy. A perturbative approach is presented to evaluate the effect of the angular correlations in the self-consistent solutions. Solutions at Fermi momenta kF in the range 1.20 - 1.75 fm-1 are reported using Argonne v 18 nucleon- nucleon potential. Although the sp potentials are sensitive to the treatment of the angular behaviour of the propagator, such sensitivity appears at momenta well above the Fermi surface. As a result, the saturation properties of symmetric nuclear matter differ marginally from those calculated using angle-averaged energy denominators in pp propagators.

  3. A demanding web-based PACS supported by web services technology

    NASA Astrophysics Data System (ADS)

    Costa, Carlos M. A.; Silva, Augusto; Oliveira, José L.; Ribeiro, Vasco G.; Ribeiro, José

    2006-03-01

    During the last years, the ubiquity of web interfaces have pushed practically all PACS suppliers to develop client applications in which clinical practitioners can receive and analyze medical images, using conventional personal computers and Web browsers. However, due to security and performance issues, the utilization of these software packages has been restricted to Intranets. Paradigmatically, one of the most important advantages of digital image systems is to simplify the widespread sharing and remote access of medical data between healthcare institutions. This paper analyses the traditional PACS drawbacks that contribute to their reduced usage in the Internet and describes a PACS based on Web Services technology that supports a customized DICOM encoding syntax and a specific compression scheme providing all historical patient data in a unique Web interface.

  4. Surgical PACS for the digital operating room. Systems engineering and specification of user requirements.

    PubMed

    Korb, Werner; Bohn, Stefan; Burgert, Oliver; Dietz, Andreas; Jacobs, Stephan; Falk, Volkmar; Meixensberger, Jürgen; Strauss, Gero; Trantakis, Christos; Lemke, Heinz U

    2006-01-01

    For better integration of surgical assist systems into the operating room, a common communication and processing plattform that is based on the users needs is needed. The development of such a system, a Surgical Picture Aquisition and Communication System (S-PACS), according the systems engineering cycle is oulined in this paper. The first two steps (concept and specification) for the engineering of the S-PACS are discussed.A method for the systematic integration of the users needs', the Quality Function Deployment (QFD), is presented. The properties of QFD for the underlying problem and first results are discussed. Finally, this leads to a first definition of an S-PACS system. PMID:16404059

  5. Jet Perturbation by HE target

    SciTech Connect

    Poulsen, P; Kuklo, R M

    2001-03-01

    We have previously reported the degree of attenuation and perturbation by a Cu jet passing through Comp B explosive. Similar tests have now been performed with high explosive (HE) targets having CJ pressures higher than and lower than the CJ pressure of Comp B. The explosives were LX-14 and TNT, respectively. We found that the measured exit velocity of the jet where it transitions from perturbed to solid did not vary significantly as a function of HE type for each HE thickness. The radial momentum imparted to the perturbed jet segment did vary as a function of HE type, however, and we report the radial spreading of the jet and the penetration of a downstream target as a function of HE type and thickness.

  6. Far-infrared photometric observations of the outer planets and satellites with Herschel-PACS

    NASA Astrophysics Data System (ADS)

    Müller, T. G.; Balog, Z.; Nielbock, M.; Moreno, R.; Klaas, U.; Moór, A.; Linz, H.; Feuchtgruber, H.

    2016-04-01

    We present all Herschel-PACS photometer observations of Mars, Saturn, Uranus, Neptune, Callisto, Ganymede, and Titan. All measurements were carefully inspected for quality problems, were reduced in a (semi-)standard way, and were calibrated. The derived flux densities are tied to the standard PACS photometer response calibration, which is based on repeated measurements of five fiducial stars. The overall absolute flux uncertainty is dominated by the estimated 5% model uncertainty of the stellar models in the PACS wavelength range between 60 and 210 μm. A comparison with the corresponding planet and satellite models shows excellent agreement for Uranus, Neptune, and Titan, well within the specified 5%. Callisto is brighter than our model predictions by about 4-8%, Ganymede by about 14-21%. We discuss possible reasons for the model offsets. The measurements of these very bright point-like sources, together with observations of stars and asteroids, demonstrate the high reliability of the PACS photometer observations and the linear behavior of the PACS bolometer source fluxes over more than four orders of magnitude (from mJy levels up to more than 1000 Jy). Our results show the great potential of using the observed solar system targets for cross-calibration purposes with other ground-based, airborne, and space-based instruments and projects. At the same time, the PACS results will lead to improved model solutions for future calibration applications. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  7. Seated postural neck and trunk reactions to sideways perturbations with or without a cognitive task.

    PubMed

    Stenlund, T C; Lundström, R; Lindroos, O; Häger, C K; Burström, L; Neely, G; Rehn, B

    2015-06-01

    Driving on irregular terrain will expose the driver to sideways mechanical shocks or perturbations that may cause musculoskeletal problems. How a cognitive task, imposed on the driver, affects seated postural reactions during perturbations is unknown. The aim of the present study was to investigate seated postural reactions in the neck and trunk among healthy adults exposed to sideways perturbations with or without a cognitive task. Twenty-three healthy male subjects aged 19-36 years, were seated on a chair mounted on a motion system and randomly exposed to 20 sideways perturbations (at two peak accelerations 5.1 or 13.2m/s(2)) in two conditions: counting backwards or not. Kinematics were recorded for upper body segments using inertial measurement units attached to the body and electromyography (EMG) was recorded for four muscles bilaterally in the neck and trunk. Angular displacements (head, neck, trunk and pelvis) in the frontal plane, and EMG amplitude (normalised to maximum voluntary contractions, MVC) were analysed. The cognitive task provoked significantly larger angular displacements of the head, neck and trunk and significantly increased EMG mean amplitudes in the upper neck during deceleration, although 10% of MVC was never exceeded. A cognitive task seems to affect musculoskeletal reactions when exposed to sideways perturbations in a seated position. PMID:25843010

  8. A collision history-based approach to Sensitivity/Perturbation calculations in the continuous energy Monte Carlo code SERPENT

    SciTech Connect

    Giuseppe Palmiotti

    2015-05-01

    In this work, the implementation of a collision history-based approach to sensitivity/perturbation calculations in the Monte Carlo code SERPENT is discussed. The proposed methods allow the calculation of the eects of nuclear data perturbation on several response functions: the eective multiplication factor, reaction rate ratios and bilinear ratios (e.g., eective kinetics parameters). SERPENT results are compared to ERANOS and TSUNAMI Generalized Perturbation Theory calculations for two fast metallic systems and for a PWR pin-cell benchmark. New methods for the calculation of sensitivities to angular scattering distributions are also presented, which adopts fully continuous (in energy and angle) Monte Carlo estimators.

  9. Perturbation theory in thermosphere dynamics

    NASA Technical Reports Server (NTRS)

    Mayr, H. G.; Volland, H.

    1976-01-01

    It is shown that density and pressure throughout the thermosphere can be adequately described in a logarithmic expansion that provides a sound basis for the application of perturbation theory. This expansion eliminates most of the important nonlinearities associated with density variations. On the basis of this expansion, the validity of perturbation theory can be extended to cover a large variety of atmospheric conditions in which the relative temperature amplitude is less than 0.5 and wind velocities are significantly less than the speed of sound.

  10. Generating the curvature perturbation at the end of inflation in string theory.

    PubMed

    Lyth, David H; Riotto, Antonio

    2006-09-22

    In brane inflationary scenarios, the cosmological perturbations are supposed to originate from the vacuum fluctuations of the inflaton field corresponding to the position of the brane. We show that a significant, and possibly dominant, contribution to the curvature perturbation is generated at the end of inflation through the vacuum fluctuations of fields, other than the inflaton, which are light during the inflationary trajectory and become heavy at the brane-antibrane annihilation. These fields appear generically in string compactifications where the background geometry has exact or approximate isometries and parametrize the internal angular directions of the brane.

  11. Generating the curvature perturbation at the end of inflation in string theory.

    PubMed

    Lyth, David H; Riotto, Antonio

    2006-09-22

    In brane inflationary scenarios, the cosmological perturbations are supposed to originate from the vacuum fluctuations of the inflaton field corresponding to the position of the brane. We show that a significant, and possibly dominant, contribution to the curvature perturbation is generated at the end of inflation through the vacuum fluctuations of fields, other than the inflaton, which are light during the inflationary trajectory and become heavy at the brane-antibrane annihilation. These fields appear generically in string compactifications where the background geometry has exact or approximate isometries and parametrize the internal angular directions of the brane. PMID:17025948

  12. Characterization of the replicon from plasmid pAC1 from Acetobacter pasteurianus.

    PubMed

    Grones, J; Králová, A; Turna, J

    1993-02-26

    A panel of recombinant plasmids pACK5 and pACT7 was prepared by introducing kanamycin and tetracycline resistance into the partially split plasmid pAC1 which contained replicon isolated from Acetobacter pasteurianus. The replicon in plasmid pAC1 is compatible with the ColE1 replicon. Compared to pBR322, the plasmid had more than 30 copies per chromosome in Escherichia coli cells. Plasmids were transformed into E. coli DH1, Acetobacter pasteurianus 3614, Acetobacter aceti 3620, Shigella, Citrobacter, and Brevibacterium flavum cells, and the stability of plasmid DNA was tested after cultivation in nonselective conditions.

  13. VizieR Online Data Catalog: Deep Herschel PACS point spread functions (Bocchio+, 2016)

    NASA Astrophysics Data System (ADS)

    Bocchio, M.; Bianchi, A.; Abergel, S.

    2016-06-01

    Herschel PACS dedicated PSF observations are scanmaps centred on various objects taken at 70 (blue channel), 100 (green channel) and 160 (red channel) um. The core of the PSF is best characterised observing faint objects (e.g. the asteroid Vesta), while the wings of the PSF can only be seen in observations of bright objects (e.g. Mars). Using a combination of images of bright and faint objects it is therefore possible to have a good characterisation of the PACS PSFs. (2 data files).

  14. Angular momentum in the Local Group

    SciTech Connect

    Dunn, A.; Laflamme, R.

    1994-04-01

    We briefly review models for the Local Group and the acquisition of its angular momentum. We describe early attempts to understand the origin of the spin of the galaxies discussing the hypothesis that the Local Group has little angular momentum. Finally we show that using Peebles` least action principle there should be a rather large amount of orbital angular momentum compared to the magnitude of the spin of its galaxies. Therefore the Local Group cannot be thought as tidally isolated. Using Peebles` trajectories we give a possible set of trajectories for Local Group galaxies which would predict their spin.

  15. A Computer Program for the Reactivity and Kinetic Parameters for Two-Dimensional Triangular Geometry by Transport Perturbation Theory.

    1990-04-25

    Version 00 TPTRIA calculates reactivity, effective delayed neutron fractions and mean generation time for two-dimensional triangular geometry on the basis of neutron transport perturbation theory. DIAMANT2 (also designated as CCC-414), is a multigroup two-dimensional discrete ordinates transport code system for triangular and hexagonal geometry which calculates direct and adjoint angular fluxes.

  16. Genetic polymorphisms in the PACAP and PAC1 receptor genes and treatment response to venlafaxine XR in generalized anxiety disorder.

    PubMed

    Cooper, Alissa J; Narasimhan, Sneha; Rickels, Karl; Lohoff, Falk W

    2013-12-30

    The pituitary adenylate cyclase-activating peptide (PACAP) and its receptor (PAC1) are involved in stress response and anxiety. Genotypes for PACAP/PAC1 were examined for effects on treatment response to venlafaxine XR in generalized anxiety disorder. The Asp54Gly (rs2856966) variant in the PACAP gene was associated with better treatment outcome.

  17. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, C. LEE COOK DIVISION, DOVER CORPORATION, STATIC PAC (TM) SYSTEM, PHASE II REPORT

    EPA Science Inventory

    The Environmental Technology Verification report discusses the technology and performance of the Static Pac System, Phase II, natural gas reciprocating compressor rod packing manufactured by the C. Lee Cook Division, Dover Corporation. The Static Pac System is designed to seal th...

  18. PAC experiments for a short range study of the Zr(10%Pr)O2 solid solution

    NASA Astrophysics Data System (ADS)

    Martínez, J. A.; Caracoche, M. C.; Rivas, P. C.; Rodríguez, A. M.

    2006-07-01

    A Zr(10 mol % Pr)O2 powder obtained by high-energy ball milling has been investigated at nanoscopic scale using primarily the Perturbed Angular Correlations technique. The aim has been to determine the nanoconfigurations around Zr4+ cations present in the solid solution and their thermal evolution with the intention of providing knowledge on the stability of the system. Results indicate that the milled product is a substitutional cubic solid solution described by two hyperfine interactions: a highly disordered interaction due to oxygen vacancies located very close to Zr4+ and an ordered interaction probably depicting a charge distribution including Pr3+ as nearest neighbor to Zr4+ probes. On cooling from high temperatures, monoclinic zirconia appears mostly at the expense of the oxygen defective cubic form. A gradual cooling indicates that destabilization of the solid solution takes place around 500°C. Thermal cycling leads to increasing amounts of the monoclinic phase.

  19. A transport based one-dimensional perturbation code for reactivity calculations in metal systems

    SciTech Connect

    Wenz, T.R.

    1995-02-01

    A one-dimensional reactivity calculation code is developed using first order perturbation theory. The reactivity equation is based on the multi-group transport equation using the discrete ordinates method for angular dependence. In addition to the first order perturbation approximations, the reactivity code uses only the isotropic scattering data, but cross section libraries with higher order scattering data can still be used with this code. The reactivity code obtains all the flux, cross section, and geometry data from the standard interface files created by ONEDANT, a discrete ordinates transport code. Comparisons between calculated and experimental reactivities were done with the central reactivity worth data for Lady Godiva, a bare uranium metal assembly. Good agreement is found for isotopes that do not violate the assumptions in the first order approximation. In general for cases where there are large discrepancies, the discretized cross section data is not accurately representing certain resonance regions that coincide with dominant flux groups in the Godiva assembly. Comparing reactivities calculated with first order perturbation theory and a straight {Delta}k/k calculation shows agreement within 10% indicating the perturbation of the calculated fluxes is small enough for first order perturbation theory to be applicable in the modeled system. Computation time comparisons between reactivities calculated with first order perturbation theory and straight {Delta}k/k calculations indicate considerable time can be saved performing a calculation with a perturbation code particularly as the complexity of the modeled problems increase.

  20. Going all digital in a university hospital: a unified large-scale PACS for multiple departments and hospitals

    NASA Astrophysics Data System (ADS)

    Vogl, Raimund

    2001-08-01

    In 1997, a large PACS was first introduced at Innsbruck University Hospital in the context of a new traumatology centre. In the subsequent years, this initial PACS setting covering only one department was expanded to most of the hospital campus, with currently some 250 viewing stations attached. Constantly connecting new modalities and viewing stations created the demand for several redesigns from the original PACS configuration to cope with the increasing data load. We give an account of these changes necessary to develop a multi hospital PACS and the considerations that lead us there. Issues of personnel for running a large scale PACS are discussed and we give an outlook to the new information systems currently under development for archiving and communication of general medical imaging data and for simple telemedicine networking between several large university hospitals.

  1. High concentration powdered activated carbon-membrane bioreactor (PAC-MBR) for slightly polluted surface water treatment at low temperature.

    PubMed

    Ma, Cong; Yu, Shuili; Shi, Wenxin; Tian, Wende; Heijman, S G J; Rietveld, L C

    2012-06-01

    In this study, different concentrations of PAC combined with MBR were carried out to treat slightly polluted surface water (SPSW) at low temperature (10°C). Effects of PAC on the efficiencies of operation, treatment, and the performance of the process were investigated. It was found that the effluent quality, performance efficiency, resistance of shock load were all enhanced and chemical irreversible membrane fouling was reduced with increasing dosage of PAC in MBR. Only when the concentration of PAC which acted as biological carriers was high enough (i.g., 50 g/L), nitrification without initial inoculation in the filtration tank could start within 19 days and be completed within 35 days at 10°C. Fifty grams per liter PAC was the optimal dosage in MBR for stable and extended operation. Under this condition, mean removal efficiencies of ammonia nitrogen (NH(3)-N), dissolved organic carbon (DOC) and UV(254) were 93%, 75%, and 85%, respectively. PMID:22386626

  2. Bacteriophage P1 pac sites inserted into the chromosome greatly increase packaging and transduction of Escherichia coli genomic DNA.

    PubMed

    Huang, Haomin; Masters, Millicent

    2014-11-01

    The Escherichia coli bacteriophage P1 packages host chromosome separately from phage DNA, and transfers it to recipient cells at low frequency in a process called generalized transduction. Phage genomes are packaged from concatemers beginning at a specific site, pac. To increase transduction rate, we have inserted pac into the chromosome at up to five equally spaced positions; at least this many are fully tolerated in the absence of P1 infection. A single chromosomal pac greatly increases transduction of downstream markers without decreasing phage yields; 3.5 × as much total chromosomal DNA is packaged. Additional insertions decrease phage yield by > 90% and also decrease phage DNA synthesis, although less dramatically. Packaging of chromosomal markers near to and downstream of each inserted pac site is, at the same time, increased by greater than 10 fold. Transduction of markers near an inserted pac site can be increased by over 1000-fold, potentially allowing identification of such transductants by screening.

  3. Matter perturbations in Galileon cosmology

    SciTech Connect

    De Felice, Antonio; Kase, Ryotaro; Tsujikawa, Shinji

    2011-02-15

    We study the evolution of matter density perturbations in Galileon cosmology where the late-time cosmic acceleration can be realized by a field kinetic energy. We obtain full perturbation equations at linear order in the presence of five covariant Lagrangians L{sub i} (i=1,{center_dot}{center_dot}{center_dot},5) satisfying the Galileon symmetry {partial_derivative}{sub {mu}}{phi}{yields}{partial_derivative}{sub {mu}}{phi}{sup +}b{sub {mu}} in the flat space-time. The equations for a matter perturbation as well as an effective gravitational potential are derived under a quasistatic approximation on subhorizon scales. This approximation can reproduce full numerical solutions with high accuracy for the wavelengths relevant to large-scale structures. For the model parameters constrained by the background expansion history of the Universe, the growth rate of matter perturbations is larger than that in the {Lambda}-cold dark matter model, with the growth index {gamma} today typically smaller than 0.4. We also find that, even on very large scales associated with the integrated-Sachs-Wolfe effect in cosmic microwave background temperature anisotropies, the effective gravitational potential exhibits a temporal growth during the transition from the matter era to the epoch of cosmic acceleration. These properties are useful to distinguish the Galileon model from the {Lambda}-cold dark matter model in future high-precision observations.

  4. Disformal invariance of curvature perturbation

    NASA Astrophysics Data System (ADS)

    Motohashi, Hayato; White, Jonathan

    2016-02-01

    We show that under a general disformal transformation the linear comoving curvature perturbation is not identically invariant, but is invariant on superhorizon scales for any theory that is disformally related to Horndeski's theory. The difference between disformally related curvature perturbations is found to be given in terms of the comoving density perturbation associated with a single canonical scalar field. In General Relativity it is well-known that this quantity vanishes on superhorizon scales through the Poisson equation that is obtained on combining the Hamiltonian and momentum constraints, and we confirm that a similar result holds for any theory that is disformally related to Horndeski's scalar-tensor theory so long as the invertibility condition for the disformal transformation is satisfied. We also consider the curvature perturbation at full nonlinear order in the unitary gauge, and find that it is invariant under a general disformal transformation if we assume that an attractor regime has been reached. Finally, we also discuss the counting of degrees of freedom in theories disformally related to Horndeski's.

  5. VHS Movies: Perturbations for Morphogenesis.

    ERIC Educational Resources Information Center

    Holmes, Danny L.

    This paper discusses the concept of a family system in terms of an interactive system of interrelated, interdependent parts and suggests that VHS movies can act as perturbations, i.e., change promoting agents, for certain dysfunctional family systems. Several distinct characteristics of a family system are defined with particular emphasis on…

  6. Adaptation Strategies in Perturbed /s/

    ERIC Educational Resources Information Center

    Brunner, Jana; Hoole, Phil; Perrier, Pascal

    2011-01-01

    The purpose of this work is to investigate the role of three articulatory parameters (tongue position, jaw position and tongue grooving) in the production of /s/. Six normal speakers' speech was perturbed by a palatal prosthesis. The fricative was recorded acoustically and through electromagnetic articulography in four conditions: (1) unperturbed,…

  7. Basics of QCD perturbation theory

    SciTech Connect

    Soper, D.E.

    1997-06-01

    This is an introduction to the use of QCD perturbation theory, emphasizing generic features of the theory that enable one to separate short-time and long-time effects. The author also covers some important classes of applications: electron-positron annihilation to hadrons, deeply inelastic scattering, and hard processes in hadron-hadron collisions. 31 refs., 38 figs.

  8. Seven topics in perturbative QCD

    SciTech Connect

    Buras, A.J.

    1980-09-01

    The following topics of perturbative QCD are discussed: (1) deep inelastic scattering; (2) higher order corrections to e/sup +/e/sup -/ annihilation, to photon structure functions and to quarkonia decays; (3) higher order corrections to fragmentation functions and to various semi-inclusive processes; (4) higher twist contributions; (5) exclusive processes; (6) transverse momentum effects; (7) jet and photon physics.

  9. PERTURBATION APPROACH FOR QUANTUM COMPUTATION

    SciTech Connect

    G. P. BERMAN; D. I. KAMENEV; V. I. TSIFRINOVICH

    2001-04-01

    We discuss how to simulate errors in the implementation of simple quantum logic operations in a nuclear spin quantum computer with many qubits, using radio-frequency pulses. We verify our perturbation approach using the exact solutions for relatively small (L = 10) number of qubits.

  10. Calculates Angular Quadrature Weights and Cosines.

    1988-02-18

    DSNQUAD calculates the angular quadrature weights and cosines for use in CCC-254/ANISN-ORNL. The subroutines in DSNQUAD were lifted from the XSDRN-PM code, which is supplied with the CCC-475/ SCALIAS-77 package.

  11. Angular velocity-based structural damage detection

    NASA Astrophysics Data System (ADS)

    Liao, Yizheng; Kiremidjian, Anne S.; Rajagopal, Ram; Loh, Chin-Hsiung

    2016-04-01

    Damage detection is an important application of structural health monitoring. With the recent development of sensing technology, additional information about structures, angular velocity, has become available. In this paper, the angular velocity signals obtained from gyroscopes are modeled as an autoregressive (AR) model. The damage sensitive features (DSFs) are defined as a function of the AR coefficients. It is found that the mean values of the DSF for the damaged and undamaged signals are different. Also, we show that the angular velocity- based AR model has a linear relationship with the acceleration-based AR model. To test the proposed damage detection method, the algorithm has been tested with the experimental data from a recent shake table test where the damage is introduced systemically. The results indicate that the change of DSF means is statistically significant, and the angular velocity-based DSFs are sensitive to damage.

  12. Angular performance measure for tighter uncertainty relations

    SciTech Connect

    Hradil, Z.; Rehacek, J.; Klimov, A. B.; Rigas, I.; Sanchez-Soto, L. L.

    2010-01-15

    The uncertainty principle places a fundamental limit on the accuracy with which we can measure conjugate quantities. However, the fluctuations of these variables can be assessed in terms of different estimators. We propose an angular performance that allows for tighter uncertainty relations for angle and angular momentum. The differences with previous bounds can be significant for particular states and indeed may be amenable to experimental measurement with the present technology.

  13. Excited D{sub s} (and Pentaquarks) in Chiral Perturbation Theory

    SciTech Connect

    Thomas Mehen

    2005-01-01

    I present results of a heavy hadron chiral perturbation theory analysis of the decays and masses of the recently discovered excited charm mesons. The present data on the electromagnetic branching ratios are consistent with heavy quark symmetry predictions and disfavor a molecular interpretation of these states. I also discuss model independent predictions for the strong decays of pentaquarks in the 10-bar representation of SU(3) which can be used to constrain the angular momentum and parity quantum numbers of these states.

  14. Angular-divergence calculation for Experimental Advanced Superconducting Tokamak neutral beam injection ion source based on spectroscopic measurements

    SciTech Connect

    Chi, Yuan; Hu, Chundong; Zhuang, Ge

    2014-02-15

    Calorimetric method has been primarily applied for several experimental campaigns to determine the angular divergence of high-current ion source for the neutral beam injection system on the Experimental Advanced Superconducting Tokamak (EAST). A Doppler shift spectroscopy has been developed to provide the secondary measurement of the angular divergence to improve the divergence measurement accuracy and for real-time and non-perturbing measurement. The modified calculation model based on the W7AS neutral beam injectors is adopted to accommodate the slot-type accelerating grids used in the EAST's ion source. Preliminary spectroscopic experimental results are presented comparable to the calorimetrically determined value of theoretical calculation.

  15. Measures and models for angular correlation and angular-linear correlation. [correlation of random variables

    NASA Technical Reports Server (NTRS)

    Johnson, R. A.; Wehrly, T.

    1976-01-01

    Population models for dependence between two angular measurements and for dependence between an angular and a linear observation are proposed. The method of canonical correlations first leads to new population and sample measures of dependence in this latter situation. An example relating wind direction to the level of a pollutant is given. Next, applied to pairs of angular measurements, the method yields previously proposed sample measures in some special cases and a new sample measure in general.

  16. [Solution of PACS to communicate with the handheld mobile intelligent equipment based on web service].

    PubMed

    Xue, Weijing; Wang, Pengcheng; Meng, Jian; Wang, Haiyang

    2013-09-01

    Using the Web Service technology, the paper puts forward a solution of remote communication between PACS and the handheld mobile intelligent devices, the characteristics of the solution are simple, easy to implement, short development cycle, high practicability, and low cost etc. PMID:24409803

  17. EST-PAC a web package for EST annotation and protein sequence prediction

    PubMed Central

    Strahm, Yvan; Powell, David; Lefèvre, Christophe

    2006-01-01

    With the decreasing cost of DNA sequencing technology and the vast diversity of biological resources, researchers increasingly face the basic challenge of annotating a larger number of expressed sequences tags (EST) from a variety of species. This typically consists of a series of repetitive tasks, which should be automated and easy to use. The results of these annotation tasks need to be stored and organized in a consistent way. All these operations should be self-installing, platform independent, easy to customize and amenable to using distributed bioinformatics resources available on the Internet. In order to address these issues, we present EST-PAC a web oriented multi-platform software package for expressed sequences tag (EST) annotation. EST-PAC provides a solution for the administration of EST and protein sequence annotations accessible through a web interface. Three aspects of EST annotation are automated: 1) searching local or remote biological databases for sequence similarities using Blast services, 2) predicting protein coding sequence from EST data and, 3) annotating predicted protein sequences with functional domain predictions. In practice, EST-PAC integrates the BLASTALL suite, EST-Scan2 and HMMER in a relational database system accessible through a simple web interface. EST-PAC also takes advantage of the relational database to allow consistent storage, powerful queries of results and, management of the annotation process. The system allows users to customize annotation strategies and provides an open-source data-management environment for research and education in bioinformatics. PMID:17147782

  18. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, C. LEE COOK DIV., DOVER CORP., STATIC PAC SYSTEM, PHASE I REPORT

    EPA Science Inventory

    The Static Pac was verified at a natural gas compressor station operated by ANR Pipeline Company. The test was carried out on two engines (8-cylinder, 2000 hp), each with two reciprocating compressors operating in parallel (4 in. rods). The evaluation focused on two shutdown proc...

  19. The Internet as a Medium of Training for Picture Archival and Communication Systems (PACS).

    ERIC Educational Resources Information Center

    Majid, Shaheen; Misra, Ramesh Kumar

    2002-01-01

    Explores the potential of Web-based training for PACS (Picture Archival and Communication Systems) used in radiology departments for the storage and archiving of patients' medical images. Reports results of studies in three hospitals in Malaysia, Singapore and the Philippines that showed that the Internet can be used effectively for training.…

  20. Broadcast Access and Reply Rights for Politicians and PACs: A Continuing Headache for the FCC.

    ERIC Educational Resources Information Center

    Gentry, Richard H.

    The major policy issues raised by Federal Communications Commission (FCC) regulations with regard to the year-round nature of political media campaigns and the emergence of political action committees (PACs) are explored in this paper. The first part of the paper introduces the major policy issues, specifically who should have an affirmative right…

  1. Design and implementation of disaster recovery and business continuity solution for radiology PACS.

    PubMed

    Mansoori, Bahar; Rosipko, Beverly; Erhard, Karen K; Sunshine, Jeffrey L

    2014-02-01

    In the digital era of radiology, picture archiving and communication system (PACS) has a pivotal role in retrieving and storing the images. Integration of PACS with all the health care information systems e.g., health information system, radiology information system, and electronic medical record has greatly improved access to patient data at anytime and anywhere throughout the entire enterprise. In such an integrated setting, seamless operation depends critically on maintaining data integrity and continuous access for all. Any failure in hardware or software could interrupt the workflow or data and consequently, would risk serious impact to patient care. Thus, any large-scale PACS now have an indispensable requirement to include deployment of a disaster recovery plan to ensure secure sources of data. This paper presents our experience with designing and implementing a disaster recovery and business continuity plan. The selected architecture with two servers in each site (local and disaster recovery (DR) site) provides four different scenarios to continue running and maintain end user service. The implemented DR at University Hospitals Health System now permits continuous access to the PACS application and its contained images for radiologists, other clinicians, and patients alike. PMID:23917863

  2. Computational cost of full QCD simulations experienced by CP-PACS and JLQCD Collaborations

    NASA Astrophysics Data System (ADS)

    Ukawa, A.

    We summarize the experience of the CP-PACS and JLQCD Collaborations on the computational cost of two-flavor full QCD simulations with improved gauge and Wilson-type quark actions. Based on the experience, estimates are made on the Tflops.years necessary for advancing full QCD studies.

  3. Impact and utilization studies of a PACS display station in an ICU setting

    NASA Astrophysics Data System (ADS)

    Andriole, Katherine P.; Storto, Maria L.; Gamsu, Gordon; Huang, H. K.

    1996-05-01

    An assessment of changes in health-care professional behavior as a result of the introduction of a PACS (picture archiving and communication system) display station to an adult medical- surgical intensive care unit (ICU) is investigated via pre- and post-PACs evaluations. ICU display station utilization and the impact on clinical operations are also examined. Parameters measured both pre- and post-PACS ICU display station placement include the number of films per patient day, the number of clinician reviews of a patient's images per day and the percentage of images on which the unit interacts with a radiologist. The elapsed times from the time of exposure to the time of: review by the referring physician, radiologist-unit interaction and clinical action based on image information are also measured. The results of this investigation suggest that the introduction of a PaCS display station in the ICU may reduce the number of exams per patient day, decrease the elapsed time from the time of exposure to the time of review by the unit clinician, and improve the time to clinical action. Note, however, that it does not appear to change the percentage of total images on which the unit interacts with a radiologist.

  4. Estimating the Number of PAC Terminals and Workstations for Library Online Catalogs.

    ERIC Educational Resources Information Center

    Machovec, George S.

    1993-01-01

    Discusses factors to consider when estimating the number of public access terminals (PACs) or workstations needed in public and academic libraries for online catalogs, including building size and layout, physical facilities, resources available through the system, peripheral equipment, graphical user interfaces, remote users, system capacity, and…

  5. Benefits of hospital-wide PACS networks: a survey of clinical users of radiology services

    NASA Astrophysics Data System (ADS)

    Bryan, Stirling; Weatherburn, Gwyneth C.; Watkins, Jessamy; Buxton, Martin J.

    1998-07-01

    An independent evaluation of PACS has been carried out at Hammersmith Hospital. This paper describes one element: the use of a questionnaire instrument to assess radiology service user's views on the quality of the service being provided; major causes of dissatisfaction with the service; the extent to which images are unavailable; and the consequences of images unavailability. The objective was to investigate some of the key claims made for the PACS technology. The principal research design was a 'before and after' comparison at Hammersmith Hospital. A number of other, comparator, hospitals were included in this survey in order to allow inferences to be made about the any observed changes at Hammersmith. The questionnaire was distributed on three occasions before PACS was operational at Hammersmith and on one occasion afterwards. Across all data collection rounds and all sites, very high levels of satisfaction with image quality were reported. When asked about satisfaction with the written reporting service, a larger proportion of respondents across all sites and rounds indicated their discontent Following the introduction of PACS, the proportion of respondents indicating that lost ward or outpatient images was a problem was significantly lower and the rate of re-examination was lower.

  6. Whole-slide imaging in pathology: the potential impact on PACS

    NASA Astrophysics Data System (ADS)

    Horii, Steven C.

    2007-03-01

    Pathology, the medical specialty charged with the evaluation of macroscopic and microscopic aspects of disease, is increasingly turning to digital imaging. While the conventional tissue blocks and glass slides form an "archive" that pathology departments must maintain, digital images acquired from microscopes or digital slide scanners are increasingly used for telepathology, consultation, and intra-facility communication. Since many healthcare facilities are moving to "enterprise PACS" with departments in addition to radiology using the infrastructure of such systems, some understanding of the potential of whole-slide digital images is important. Network and storage designers, in particular, are very likely to be impacted if a significant number of such images are to be moved on, or stored (even temporarily) in, enterprise PACS. As an example, a typical commercial whole-slide imaging system typically generates 15 gigabytes per slide scanned (per focal plane). Many of these whole-slide scanners have a throughput of 1000 slides per day. If that full capacity is used and all the resulting digital data is moved to the enterprise PACS, it amounts to 15 terabytes per day; the amount of data a large radiology department might generate in a year or two. This paper will review both the clinical scenarios of whole-slide imaging as well as the resulting data volumes. The author will emphasize the potential PACS infrastructure impact of such huge data volumes.

  7. Galactic angular momenta and angular momentum couplings in the large-scale structure

    NASA Astrophysics Data System (ADS)

    Schäfer, Björn Malte; Merkel, Philipp M.

    2012-04-01

    In this paper, we revisit the acquisition of angular momentum of galaxies by tidal shearing and compute the angular momentum variance ? as well as the angular momentum correlation function CL(r), using tidal torquing in the Zel'dovich approximation as the model for angular momentum build-up. Under the assumption that haloes form at peaks in the density field we determine the protohalo's inertia from the peak shape and embed it in a tidal field. Inertia and shear are drawn from a random process and we compute the angular momentum variance and correlation function by sampling from a Gaussian distribution which shows the correct covariances between all relevant quantities. We describe the way in which the correlations in angular momentum result from an interplay of long-ranged correlations in the tidal shear and short-ranged correlations in the inertia field. Our description takes care of the relative orientation of the eigensystems of these two symmetric tensors. We propose a new form of the angular momentum correlation function which is able to distinguish between parallel and antiparallel alignment of angular momentum vectors, and comment on implications of intrinsic alignments for weak lensing measurements. We confirm the scaling L/M ∝ M2/3 and find the angular momentum distribution of Milky Way sized haloes to be correlated on scales of ˜1 Mpc h-1. The correlation function can be well fitted by an empirical relation of the form CL(r) ∝ exp(-[r/r0]β).

  8. PAC investigations of radiation damage annealing in 111In implanted ZnO

    NASA Astrophysics Data System (ADS)

    Dogra, R.; Byrne, A. P.; Ridgway, M. C.

    2009-08-01

    The structural and electronic environment about implanted radioactive 111In(→ 111Cd) probe atoms as a function of annealing temperature in a single crystal of ZnO(0 0 0 1) has been monitored on an atomic scale using perturbed angular correlation technique, a nuclear hyperfine method. This technique is based upon the hyperfine interaction of the nuclear electric quadrupole moment or magnetic moment of the probes, respectively, with the electric field gradient or magnetic hyperfine field arising from the extra-nuclear electronic charges and spin distributions. The probe atoms 111In were recoil-implanted at room temperature following heavy-ion nuclear reactions. The electric quadrupole interaction was measured at room temperature for as-implanted and annealed samples. The thermal annealing in ambient nitrogen up to 1000 °C showed a progressive reduction of disorder around the probe atom as evidenced via continual decrease in width of the distribution of quadrupole interaction frequencies. Present measurements suggested that annealing at 800 °C for 30 min in flowing nitrogen is enough to produce an optimum recovery of crystallinity. After annealing of radiation damage at 1000 °C we observed an axially symmetric electric field gradient which is characterized by the unique quadrupole interaction frequency of 30.6(3) MHz and a frequency distribution of width nearly zero. The observed electric field gradient was attributed to substitutional incorporation of probe atoms at cation-sites of ZnO. In contrast to annealing in ambient nitrogen at 1000 °C, air annealing of 111In implanted ZnO samples revealed change in local stoichiometry about probe atoms which is attributed to the internal oxidation of the indium probes. The measured electric field gradient and asymmetry parameter at cation-sites of ZnO have been compared with theoretical calculations using a simple point charge model.

  9. Maple procedures for the coupling of angular momenta. VIII. Spin-angular coefficients for single-shell configurations

    NASA Astrophysics Data System (ADS)

    Gaigalas, G.; Scharf, O.; Fritzsche, S.

    2005-03-01

    very beginning, the RACAH program has been designed as an interactive environment for the (symbolic) manipulation and computation of expressions from the theories of angular momentum and the atomic shell model. With the present extension of the program, we provide the user with a simple access to the coefficients of fractional grandparentage (CFGP) as well as to the spin-angular coefficients of one- and two-particle physical operators. To facilitate the specification of the tensorial form of the operators, a short but powerful notation has been introduced for the creation and annihilation operators as well as for the products of such operators as required for the development of many-body perturbation theory in a symmetry-adapted basis. All the coefficients and the matrix elements from above are equally supported for both LS- and jj-coupled operators and functions. The main procedures of the present extension are described below in Appendix B. In addition, a list of all available commands of the RACAH program can be found in the file Racah-commands.ps which is distributed together with the code. Typical running time: The program replies promptly on most requests. Even large tabulations of standard quantities and pure spin-angular coefficients for one- and two-particle scalar operators in LS- and jj-coupling can be carried out in a few (tens of) seconds.

  10. Implementation and Validation of PACS Integrated Peer Review for Discrepancy Recording of Radiology Reporting.

    PubMed

    Olthof, A W; van Ooijen, P M A

    2016-09-01

    The purpose of this work is to demonstrate the possibility of implementation of a PACS-integrated peer review system based on RADPEER™ classification providing a step-wise implementation plan utilizing features already present in the standard PACS implementation and without the requirement of additional software development. Furthermore, we show the usage and effects of the system during the first 30 months of usage. To allow fast and easy implementation into the daily workflow the key-word feature of the PACS was used. This feature allows to add a key-word to an imaging examination for easy searching in the PACS database (e.g. by entering keywords for different kinds of pathology). For peer review we implemented a keyword structure including a code for each of the existing RADPEER™ scoring language terms and a keyword with the phrase "second reading" followed by the name of the individual radiologist. The use of the short-keys to enter the codes in relation to the peer review was a simple to use solution. During the study 599 reports were peer reviewed. The active participation in this study of the radiologists varies and ranges from 3 to 327 reviews per radiologist. The number of peer review is highest in CT and CR. There are no significant technical obstacles to implement a PACS-integrated RADPEER™ -system based on key-words allowing easy integration of peer review into the daily routine without the requirement of additional software. Peer review implemented in a non-random setting based on relevant priors could already help in increasing the quality of radiological reporting and serve as continuing education among peers. Decisiveness, tact and trust are needed to promote use of the system and collaborative discussion of the results by radiologist. PMID:27443339

  11. DICOM for Clinical Research: PACS-Integrated Electronic Data Capture in Multi-Center Trials.

    PubMed

    Haak, Daniel; Page, Charles-E; Reinartz, Sebastian; Krüger, Thilo; Deserno, Thomas M

    2015-10-01

    Providing surrogate endpoints in clinical trials, medical imaging has become increasingly important in human-centered research. Nowadays, electronic data capture systems (EDCS) are used but binary image data is integrated insufficiently. There exists no structured way, neither to manage digital imaging and communications in medicine (DICOM) data in EDCS nor to interconnect EDCS with picture archiving and communication systems (PACS). Manual detours in the trial workflow yield errors, delays, and costs. In this paper, requirements for a DICOM-based system interconnection of EDCS and research PACS are analysed. Several workflow architectures are compared. Optimized for multi-center trials, we propose an entirely web-based solution integrating EDCS, PACS, and DICOM viewer, which has been implemented using the open source projects OpenClinica, DCM4CHEE, and Weasis, respectively. The EDCS forms the primary access point. EDCS to PACS interchange is integrated seamlessly on the data and the context levels. DICOM data is viewed directly from the electronic case report form (eCRF), while PACS-based management is hidden from the user. Data privacy is ensured by automatic de-identification and re-labelling with study identifiers. Our concept is evaluated on a variety of 13 DICOM modalities and transfer syntaxes. We have implemented the system in an ongoing investigator-initiated trial (IIT), where five centers have recruited 24 patients so far, performing decentralized computed tomography (CT) screening. Using our system, the chief radiologist is reading DICOM data directly from the eCRF. Errors and workflow processing time are reduced. Furthermore, an imaging database is built that may support future research. PMID:26001521

  12. High In Vitro Antibacterial Activity of Pac-525 against Porphyromonas gingivalis Biofilms Cultured on Titanium

    PubMed Central

    Li, Ji-yin; Wang, Xue-jin; Wang, Li-na; Ying, Xiao-xia; Ren, Xiang; Liu, Hui-ying; Xu, Li; Ma, Guo-wu

    2015-01-01

    In order to investigate the potential of short antimicrobial peptides (AMPs) as alternative antibacterial agents during the treatment of peri-implantitis, the cytotoxic activity of three short AMPs, that is, Pac-525, KSL-W, and KSL, was determined using the MTT assay. The antimicrobial activity of these AMPs, ranging in concentration from 0.0039 mg/mL to 0.5 mg/mL, against the predominant planktonic pathogens, including Streptococcus sanguis, Fusobacterium nucleatum, and Porphyromonas gingivalis, involved in peri-implantitis was investigated. Furthermore, 2-day-old P. gingivalis biofilms cultured on titanium surfaces were treated with Pac-525 and subsequently observed and analysed using confocal laser scanning microscopy (CLSM). The average cell proliferation curve indicated that there was no cytotoxicity due to the three short AMPs. The minimum inhibitory concentration and minimum bactericidal concentration values of Pac-525 were 0.0625 mg/mL and 0.125 mg/mL, respectively, for P. gingivalis and 0.0078 mg/mL and 0.0156 mg/mL, respectively, for F. nucleatum. Using CLSM, we confirmed that compared to 0.1% chlorhexidine, 0.5 mg/mL of Pac-525 caused a significant decrease in biofilm thickness and a decline in the percentage of live bacteria. These data indicate that Pac-525 has unique properties that might make it suitable for the inhibition the growth of pathogenic bacteria around dental implants. PMID:25710035

  13. Neptune's story. [Triton's orbit perturbation

    NASA Technical Reports Server (NTRS)

    Goldreich, P.; Murray, N.; Longaretti, P. Y.; Banfield, D.

    1989-01-01

    It is conjectured that Triton was captured from a heliocentric orbit as the result of a collision with what was then one of Neptune's regular satellites. The immediate post-capture orbit was highly eccentric. Dissipation due to tides raised by Neptune in Triton caused Triton's orbit to evolve to its present state in less than one billion years. For much of this time Triton was almost entirely molten. While its orbit was evolving, Triton cannibalized most of the regular satellites of Neptune and also perturbed Nereid, thus accounting for that satellite's highly eccentric and inclined orbit. The only regular satellites of Neptune that survived were those that formed well within 5 Neptune radii, and they move on inclined orbits as the result of chaotic perturbations forced by Triton.

  14. The status of perturbative QCD

    SciTech Connect

    Ellis, R.K.

    1988-10-01

    The advances in perturbative QCD are reviewed. The status of determinations of the coupling constant ..cap alpha../sub S/ and the parton distribution functions is presented. New theoretical results on the spin dependent structure functions of the proton are also reviewed. The theoretical description of the production of vector bosons, jets and heavy quarks is outlined with special emphasis on new results. Expected rates for top quark production at hadronic colliders are presented. 111 refs., 8 figs.

  15. Quantum fields with classical perturbations

    SciTech Connect

    Dereziński, Jan

    2014-07-15

    The main purpose of these notes is a review of various models of Quantum Field Theory (QFT) involving quadratic Lagrangians. We discuss scalar and vector bosons, spin 1/2 fermions, both neutral and charged. Beside free theories, we study their interactions with classical perturbations, called, depending on the context, an external linear source, mass-like term, current or electromagnetic potential. The notes may serve as a first introduction to QFT.

  16. Perturbation growth in accreting filaments

    NASA Astrophysics Data System (ADS)

    Clarke, S. D.; Whitworth, A. P.; Hubber, D. A.

    2016-05-01

    We use smoothed particle hydrodynamic simulations to investigate the growth of perturbations in infinitely long filaments as they form and grow by accretion. The growth of these perturbations leads to filament fragmentation and the formation of cores. Most previous work on this subject has been confined to the growth and fragmentation of equilibrium filaments and has found that there exists a preferential fragmentation length-scale which is roughly four times the filament's diameter. Our results show a more complicated dispersion relation with a series of peaks linking perturbation wavelength and growth rate. These are due to gravo-acoustic oscillations along the longitudinal axis during the sub-critical phase of growth. The positions of the peaks in growth rate have a strong dependence on both the mass accretion rate onto the filament and the temperature of the gas. When seeded with a multiwavelength density power spectrum, there exists a clear preferred core separation equal to the largest peak in the dispersion relation. Our results allow one to estimate a minimum age for a filament which is breaking up into regularly spaced fragments, as well as an average accretion rate. We apply the model to observations of filaments in Taurus by Tafalla & Hacar and find accretion rates consistent with those estimated by Palmeirim et al.

  17. R evolution: Improving perturbative QCD

    SciTech Connect

    Hoang, Andre H.; Jain, Ambar; Stewart, Iain W.; Scimemi, Ignazio

    2010-07-01

    Perturbative QCD results in the MS scheme can be dramatically improved by switching to a scheme that accounts for the dominant power law dependence on the factorization scale in the operator product expansion. We introduce the ''MSR scheme'' which achieves this in a Lorentz and gauge invariant way and has a very simple relation to MS. Results in MSR depend on a cutoff parameter R, in addition to the {mu} of MS. R variations can be used to independently estimate (i.) the size of power corrections, and (ii.) higher-order perturbative corrections (much like {mu} in MS). We give two examples at three-loop order, the ratio of mass splittings in the B*-B and D*-D systems, and the Ellis-Jaffe sum rule as a function of momentum transfer Q in deep inelastic scattering. Comparing to data, the perturbative MSR results work well even for Q{approx}1 GeV, and power corrections are reduced compared to MS.

  18. Ultrafast angular momentum transfer in multisublattice ferrimagnets.

    PubMed

    Bergeard, N; López-Flores, V; Halté, V; Hehn, M; Stamm, C; Pontius, N; Beaurepaire, E; Boeglin, C

    2014-01-01

    Femtosecond laser pulses can be used to induce ultrafast changes of the magnetization in magnetic materials. However, one of the unsolved questions is that of conservation of the total angular momentum during the ultrafast demagnetization. Here we report the ultrafast transfer of angular momentum during the first hundred femtoseconds in ferrimagnetic Co0.8Gd0.2 and Co0.74Tb0.26 films. Using time-resolved X-ray magnetic circular dichroism allowed for time-resolved determination of spin and orbital momenta for each element. We report an ultrafast quenching of the magnetocrystalline anisotropy and show that at early times the demagnetization in ferrimagnetic alloys is driven by the local transfer of angular momenta between the two exchange-coupled sublattices while the total angular momentum stays constant. In Co0.74Tb0.26 we have observed a transfer of the total angular momentum to an external bath, which is delayed by ~150 fs. PMID:24614016

  19. Angular correlation between proton and neutron rotors

    NASA Astrophysics Data System (ADS)

    Tajima, N.

    2013-07-01

    A brief review is given on the controversy and its solution about the fact that the angular momentum vector of protons and that of neutrons in well-deformed nuclei at low total angular momenta have a strong correlation that they are oriented in opposite directions. In a simple two-rotor model in 2-dimensional space, this fact is explained as originating from the quantum mechanical uncertainty relation between the angle and the angular momentum for the relative rotation of the two rotors. As the second topic, a more realistic model consisting of two triaxial rotors in 3-dimensional space coupled with a QQ interaction is employed to investigate a possible shears-band-like collective rotation predicted by T. Otsuka, in which the angle at which the angular momentum of protons and that of neutrons intersect changes continuously from 180° at spin zero toward 0° at high spins within the same rotational band. The probability distributions of the angle between the two angular momenta and the angle between the longest principal axes of two rotors are calculated to examine the participation of the scissors mode in the evolution of the ground rotational band versus spin.

  20. Angular-planar CMB power spectrum

    SciTech Connect

    Pereira, Thiago S.; Abramo, L. Raul

    2009-09-15

    Gaussianity and statistical isotropy of the Universe are modern cosmology's minimal set of hypotheses. In this work we introduce a new statistical test to detect observational deviations from this minimal set. By defining the temperature correlation function over the whole celestial sphere, we are able to independently quantify both angular and planar dependence (modulations) of the CMB temperature power spectrum over different slices of this sphere. Given that planar dependence leads to further modulations of the usual angular power spectrum C{sub l}, this test can potentially reveal richer structures in the morphology of the primordial temperature field. We have also constructed an unbiased estimator for this angular-planar power spectrum which naturally generalizes the estimator for the usual C{sub l}'s. With the help of a chi-square analysis, we have used this estimator to search for observational deviations of statistical isotropy in WMAP's 5 year release data set (ILC5), where we found only slight anomalies on the angular scales l=7 and l=8. Since this angular-planar statistic is model-independent, it is ideal to employ in searches of statistical anisotropy (e.g., contaminations from the galactic plane) and to characterize non-Gaussianities.

  1. Angular momentum conservation for dynamical black holes

    SciTech Connect

    Hayward, Sean A.

    2006-11-15

    Angular momentum can be defined by rearranging the Komar surface integral in terms of a twist form, encoding the twisting around of space-time due to a rotating mass, and an axial vector. If the axial vector is a coordinate vector and has vanishing transverse divergence, it can be uniquely specified under certain generic conditions. Along a trapping horizon, a conservation law expresses the rate of change of angular momentum of a general black hole in terms of angular momentum densities of matter and gravitational radiation. This identifies the transverse-normal block of an effective gravitational-radiation energy tensor, whose normal-normal block was recently identified in a corresponding energy conservation law. Angular momentum and energy are dual, respectively, to the axial vector and a previously identified vector, the conservation equations taking the same form. Including charge conservation, the three conserved quantities yield definitions of an effective energy, electric potential, angular velocity and surface gravity, satisfying a dynamical version of the so-called first law of black-hole mechanics. A corresponding zeroth law holds for null trapping horizons, resolving an ambiguity in taking the null limit.

  2. Ultrafast angular momentum transfer in multisublattice ferrimagnets.

    PubMed

    Bergeard, N; López-Flores, V; Halté, V; Hehn, M; Stamm, C; Pontius, N; Beaurepaire, E; Boeglin, C

    2014-03-11

    Femtosecond laser pulses can be used to induce ultrafast changes of the magnetization in magnetic materials. However, one of the unsolved questions is that of conservation of the total angular momentum during the ultrafast demagnetization. Here we report the ultrafast transfer of angular momentum during the first hundred femtoseconds in ferrimagnetic Co0.8Gd0.2 and Co0.74Tb0.26 films. Using time-resolved X-ray magnetic circular dichroism allowed for time-resolved determination of spin and orbital momenta for each element. We report an ultrafast quenching of the magnetocrystalline anisotropy and show that at early times the demagnetization in ferrimagnetic alloys is driven by the local transfer of angular momenta between the two exchange-coupled sublattices while the total angular momentum stays constant. In Co0.74Tb0.26 we have observed a transfer of the total angular momentum to an external bath, which is delayed by ~150 fs.

  3. An orbital angular momentum spectrometer for electrons

    NASA Astrophysics Data System (ADS)

    Harvey, Tyler; Grillo, Vincenzo; McMorran, Benjamin

    2016-05-01

    With the advent of techniques for preparation of free-electron and neutron orbital angular momentum (OAM) states, a basic follow-up question emerges: how do we measure the orbital angular momentum state distribution in matter waves? Control of both the energy and helicity of light has produced a range of spectroscopic applications, including molecular fingerprinting and magnetization mapping. Realization of an analogous dual energy-OAM spectroscopy with matter waves demands control of both initial and final energy and orbital angular momentum states: unlike for photons, final state post-selection is necessary for particles that cannot be annihilated. We propose a magnetic field-based mechanism for quantum non-demolition measurement of electron OAM. We show that OAM-dependent lensing is produced by an operator of form U =exp iLzρ2/ℏb2 where ρ =√{x2 +y2 } is the radial position operator, Lz is the orbital angular momentum operator along z, and b is the OAM dispersion length. We can physically realize this operator as a term in the time evolution of an electron in magnetic round lens. We discuss prospects and practical challenges for implementation of a lensing orbital angular momentum measurement. This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under the Early Career Research Program Award # DE-SC0010466.

  4. Weak lensing generated by vector perturbations and detectability of cosmic strings

    SciTech Connect

    Yamauchi, Daisuke; Namikawa, Toshiya; Taruya, Atsushi E-mail: namikawa@utap.phys.s.u-tokyo.ac.jp

    2012-10-01

    We study the observational signature of vector metric perturbations through the effect of weak gravitational lensing. In the presence of vector perturbations, the non-vanishing signals for B-mode cosmic shear and curl-mode deflection angle, which have never appeared in the case of scalar metric perturbations, naturally arise. Solving the geodesic and geodesic deviation equations, we drive the full-sky formulas for angular power spectra of weak lensing signals, and give the explicit expressions for E-/B-mode cosmic shear and gradient-/curl-mode deflection angle. As a possible source for seeding vector perturbations, we then consider a cosmic string network, and discuss its detectability from upcoming weak lensing and CMB measurements. Based on the formulas and a simple model for cosmic string network, we calculate the angular power spectra and expected signal-to-noise ratios for the B-mode cosmic shear and curl-mode deflection angle. We find that the weak lensing signals are enhanced for a smaller intercommuting probability of the string network, P, and they are potentially detectable from the upcoming cosmic shear and CMB lensing observations. For P ∼ 10{sup −1}, the minimum detectable tension of the cosmic string will be down to Gμ ∼ 5 × 10{sup −8}. With a theoretically inferred smallest value P ∼ 10{sup −3}, we could even detect the string with Gμ ∼ 5 × 10{sup −10}.

  5. Variation in Angular Velocity and Angular Acceleration of a Particle in Rectilinear Motion

    ERIC Educational Resources Information Center

    Mashood, K. K.; Singh, V. A.

    2012-01-01

    We discuss the angular velocity ([image omitted]) and angular acceleration ([image omitted]) associated with a particle in rectilinear motion with constant acceleration. The discussion was motivated by an observation that students and even teachers have difficulty in ascribing rotational motion concepts to a particle when the trajectory is a…

  6. Molecular-frame photoelectron angular distributions Molecular-frame photoelectron angular distributions

    NASA Astrophysics Data System (ADS)

    Lucchese, Robert R.; Stolow, Albert

    2012-10-01

    Angle-resolved photoelectron measurements in molecular ionization continue to grow in importance due to their sensitivity to molecular dynamics combined with their avoidance of deleterious averaging over molecular orientation. This special issue contains only regularly refereed articles and provides an account of current experimental and theoretical studies of such molecular-frame photoelectron angular distributions (MFPADs). Recent experimental activity in this field has been stimulated by advances in light sources such as x-ray free electron lasers, attosecond XUV laser pulses and phase-stable ultrashort strong laser fields. This effort is further amplified by recent developments in coincidence detection and molecular-frame alignment/orientation techniques. Beyond perturbative light-matter interactions, strong field processes such as tunnel ionization, above threshold ionization and rescattering phenomena such as high harmonic generation and laser-induced electron diffraction are beginning to probe molecular-frame photoelectron-molecule scattering dynamics. Theoretical developments are playing an equally important role in furthering molecular-frame photoelectron science. This issue contains several purely theoretical papers that aim to provide insight into possible schemes for using MFPADs in the study of molecular dynamics. Because the details of the electron-molecule scattering dynamics are important to the interpretation of experimental data, significant progress is made by a close collaboration between theory and experiment. There are a number of such contributions in this issue that combine theory and experiment to obtain a detailed understanding of the observed processes. One recurring theme is the use of measured MFPADs as probes of the molecular state and to uncover information about the dynamics of molecular systems. Contributions in this issue consider using MFPADs to investigate molecular geometry or the rotational, vibrational or electronic state of a

  7. Angular Coefficients Measurement of Drell-Yan Dielectron Pairs at CDF

    NASA Astrophysics Data System (ADS)

    Han, Jiyeon; CDF Collaboration

    2011-04-01

    We report on the measurement of the angular distributions of final state electrons in p p ->γ* / Z ->e+ e events produced in the Z boson region mass range of 66 to 116 GeV/c2 from 2.1 fb-1 of proton anti-proton collisions at √{ s} = 1 . 96 TeV taken by the CDF detector at Fermilab. The transverse momentum (PT) dependent angular coefficients A0, A2, A3, and A4 are compared with several predictions based on Quantum Chromodymnamics (QCD). The PT dependence of A0 and A2 is in agreement with the predictions of perturbative QCD and shows that the production of Z bosons at large PT proceeds via a combination of the quark-antiquark annihilation and the quark-gluon Compton processes. We find a good agreement with the Lam-Tung relation (A0 = A2), which implies that the spin of the gluon is 1.

  8. Characterization of Optical Components for the Cosmology Large Angular Scale Surveyor (CLASS)

    NASA Astrophysics Data System (ADS)

    Zhang, Zhuo; Essinger-Hileman, Thomas; Xu, Zhilei; Marriage, Tobias

    2016-06-01

    Inflation theory posits a rapid expansion at the beginning of the universe that explains the homogeneity, isotropy and flatness of our universe. The theory postulates perturbations to space-time with both scalar and tensor components, the latter of which would give rise to a "B-mode" polarization in the Cosmic Microwave Background (CMB). The Cosmology Large Angular Scale Surveyor (CLASS), with its broadband frequency coverage and rapid front-end modulation, has the unique ability to map the entire B-mode angular power spectrum where there the inflationary signal is expected to dominate. In this poster, I give an overview of CLASS and present work on the characterization of CLASS optical components, including infrared filters, using a custom Fourier Transform Interferometer.

  9. Bringing "The Moth" to Light: A Planet-Perturbed Disk Scenario for the HD 61005 System

    NASA Astrophysics Data System (ADS)

    Esposito, Thomas M.; Fitzgerald, Michael P.; Graham, James R.; Kalas, Paul G.; Millar-Blanchaer, Max; Wang, Jason

    2015-12-01

    The HD 61005 debris disk ("The Moth") is notable for its unusual swept-back "wing" morphology, brightness asymmetries, dust ring offset, and a cleared region inside of ~50 AU. Here we present Gemini Planet Imager data that reveal this disk in scattered light down to Jupiter-like separations of <10 AU. Complementary W.M. Keck NIRC2/AO J,H,K imaging shows the disk's outer regions with high angular resolution. Based on these data, we propose a new explanation for the disk's features: that of an unseen planet on an inclined, eccentric orbit perturbing the disk material. To test this scenario, we used secular perturbation theory to construct 3-D dust distributions that informed 2-D scattered-light models, which we then compared with the data via an MCMC analysis. We found that the best-fit models reproduced morphological disk features similar to those observed, indicating that the perturber scenario is plausible for this system.

  10. Performance of a partial PACS and its application to the development of a fully integrated digital medical imaging department in a community hospital

    NASA Astrophysics Data System (ADS)

    Nosil, Josip; Scobie, Duncan L.; Justice, Gerald C.; Clark, R. P.; Ritchie, Gordon W.; Weigl, Wilhelm J.; Gnoyke, Hartmut; Fisher, Paul D.

    1990-08-01

    Victoria General Hospital, which is a part of the Greater Victoria Hospital Society, is a 443 bed community hospital with a full-service medical imaging department that includes MRI. In August 1987, four rooms (chest radiography, GI fluorography, CT, and cardiac angiography) were connected to a Picture Archive and Communications System (PACS). We present the experience gained from two years of study with this prototype PACS and briefly describe its hardware and software configuration. Reported in detail is the measured image transfer performance of the PACS for each of the four image sources. Conventional films require more than 150 seconds from exposure to film availability for reporting. Using PACS, chest and GI images take 77 seconds per image from exposure to viewing, 31 secs for CT, and 40 secs for general angiography. The elapsed times with PACS between the various software processes for each modality, and those needed to set up image archive folders are detailed. The present imaging equipment at VGH, a typical community hospital, is specified and is to be integrated into a department-wide PACS. Required PACS performance levels relative to the clinical demands are described, and compared with the current PACS. The information and experience acquired by testing the VGH PACS has been used in the planning of the full implementation of PACS at VGH (ref. 10. Fisher et al). The next phase (3C) of PACS implementation is described.

  11. Cosmological perturbations: Vorticity, isocurvature and magnetic fields

    NASA Astrophysics Data System (ADS)

    Christopherson, Adam J.

    2014-10-01

    In this paper, I review some recent, interlinked, work undertaken using cosmological perturbation theory — a powerful technique for modeling inhomogeneities in the universe. The common theme which underpins these pieces of work is the presence of nonadiabatic pressure, or entropy, perturbations. After a brief introduction covering the standard techniques of describing inhomogeneities in both Newtonian and relativistic cosmology, I discuss the generation of vorticity. As in classical fluid mechanics, vorticity is not present in linearized perturbation theory (unless included as an initial condition). Allowing for entropy perturbations, and working to second order in perturbation theory, I show that vorticity is generated, even in the absence of vector perturbations, by purely scalar perturbations, the source term being quadratic in the gradients of first order energy density and isocurvature, or nonadiabatic pressure perturbations. This generalizes Crocco's theorem to a cosmological setting. I then introduce isocurvature perturbations in different models, focusing on the entropy perturbation in standard, concordance cosmology, and in inflationary models involving two scalar fields. As the final topic, I investigate magnetic fields, which are a potential observational consequence of vorticity in the early universe. I briefly review some recent work on including magnetic fields in perturbation theory in a consistent way. I show, using solely analytical techniques, that magnetic fields can be generated by higher order perturbations, albeit too small to provide the entire primordial seed field, in agreement with some numerical studies. I close this paper with a summary and some potential extensions of this work.

  12. Geometric Hamiltonian structures and perturbation theory

    SciTech Connect

    Omohundro, S.

    1984-08-01

    We have been engaged in a program of investigating the Hamiltonian structure of the various perturbation theories used in practice. We describe the geometry of a Hamiltonian structure for non-singular perturbation theory applied to Hamiltonian systems on symplectic manifolds and the connection with singular perturbation techniques based on the method of averaging.

  13. Superconvergent perturbation method in quantum mechanics

    SciTech Connect

    Scherer, W. )

    1995-02-27

    An analog of Kolmogorov's superconvergent perturbation theory in classical mechanics is constructed for self-adjoint operators. It is different from the usual Rayleigh-Schroedinger perturbation theory and yields expansions for eigenvalues and eigenvectors in terms of functions of the perturbation parameter.

  14. Inequalities for angular derivatives and boundary interpolation

    NASA Astrophysics Data System (ADS)

    Bolotnikov, Vladimir; Elin, Mark; Shoikhet, David

    2013-03-01

    The classical Julia-Wolff-Carathéodory theorem asserts that the angular derivative of a holomorphic self-mapping of the open unit disk (Schur function) at its boundary fixed point is a positive number. Cowen and Pommerenke (J Lond Math Soc 26:271-289, 1982) proved that if a Schur function has several boundary regular fixed (or mutual contact) points, then the angular derivatives at these points are subject to certain inequalities. We develop a unified approach to establish relations between angular derivatives of Schur functions with a prescribed (possibly, infinite) collection of either mutual contact points or boundary fixed points. This approach yields diverse inequalities improving both classical and more recent results. We apply them to study the Nevanlinna-Pick interpolation problem with boundary data. Our methods lead to fairly explicit formulas describing the set of solutions.

  15. Angular correlations and high energy evolution

    SciTech Connect

    Kovner, Alex; Lublinsky, Michael

    2011-11-01

    We address the question of to what extent JIMWLK evolution is capable of taking into account angular correlations in a high energy hadronic wave function. Our conclusion is that angular (and indeed other) correlations in the wave function cannot be reliably calculated without taking into account Pomeron loops in the evolution. As an example we study numerically the energy evolution of angular correlations between dipole scattering amplitudes in the framework of the large N{sub c} approximation to JIMWLK evolution (the 'projectile dipole model'). Target correlations are introduced via averaging over an (isotropic) ensemble of anisotropic initial conditions. We find that correlations disappear very quickly with rapidity even inside the saturation radius. This is in accordance with our physical picture of JIMWLK evolution. The actual correlations inside the saturation radius in the target QCD wave function, on the other hand, should remain sizable at any rapidity.

  16. Surface angular momentum of light beams.

    PubMed

    Ornigotti, Marco; Aiello, Andrea

    2014-03-24

    Traditionally, the angular momentum of light is calculated for "bullet-like" electromagnetic wave packets, although in actual optical experiments "pencil-like" beams of light are more commonly used. The fact that a wave packet is bounded transversely and longitudinally while a beam has, in principle, an infinite extent along the direction of propagation, renders incomplete the textbook calculation of the spin/orbital separation of the angular momentum of a light beam. In this work we demonstrate that a novel, extra surface part must be added in order to preserve the gauge invariance of the optical angular momentum per unit length. The impact of this extra term is quantified by means of two examples: a Laguerre-Gaussian and a Bessel beam, both circularly polarized.

  17. Improved numerical projection of angular momentum

    NASA Astrophysics Data System (ADS)

    O'Mara, Kevin; Johnson, Calvin

    2015-10-01

    Nuclear many-body states have good angular momenta, but many theoretical building blocks such as deformed Slater determinants do not. Hence one must numerically project out states of good angular momenta, usually through a computationally taxing three-dimensional integral. We took an existing code for angular-momentum projected Hartree-Fock and improved its performance, partly through judicious ordering of the loops, precomputing arrays of important combinatorics, and careful application of parallelization. We also investigated a novel inversion scheme. This work is potentially applicable to multiple approaches in many-body calculations, and should also be generalizable to particle number projection. Supported by SDSU Summer Undergraduate Research Program and by DOE Award Number DE-FG02-96ER40985.

  18. RECONSTRUCTING COSMOLOGICAL MATTER PERTURBATIONS USING STANDARD CANDLES AND RULERS

    SciTech Connect

    Alam, Ujjaini; Sahni, Varun; Starobinsky, Alexei A. E-mail: varun@iucaa.ernet.i

    2009-10-20

    For a large class of dark energy (DE) models, for which the effective gravitational constant is a constant and there is no direct exchange of energy between DE and dark matter (DM), knowledge of the expansion history suffices to reconstruct the growth factor of linearized density perturbations in the non-relativistic matter component on scales much smaller than the Hubble distance. In this paper, we develop a non-parametric method for extracting information about the perturbative growth factor from data pertaining to the luminosity or angular size distances. A comparison of the reconstructed density contrast with observations of large-scale structure and gravitational lensing can help distinguish DE models such as the cosmological constant and quintessence from models based on modified gravity theories as well as models in which DE and DM are either unified or interact directly. We show that for current supernovae (SNe) data, the linear growth factor at z = 0.3 can be constrained to 5% and the linear growth rate to 6%. With future SNe data, such as expected from the Joint Dark Energy Mission, we may be able to constrain the growth factor to 2%-3% and the growth rate to 3%-4% at z = 0.3 with this unbiased, model-independent reconstruction method. For future baryon acoustic oscillation data which would deliver measurements of both the angular diameter distance and the Hubble parameter, it should be possible to constrain the growth factor at z = 2.5%-9%. These constraints grow tighter with the errors on the data sets. With a large quantity of data expected in the next few years, this method can emerge as a competitive tool for distinguishing between different models of dark energy.

  19. Reconstructing cosmological matter perturbations using standard candles and rulers

    SciTech Connect

    Alam, Ujjaini; Sahni, Varun; Starobinsky, Alexei A

    2008-01-01

    For a large class of dark energy (DE) models, for which the effective gravitational constant is a constant and there is no direct exchange of energy between DE and dark matter (DM), knowledge of the expansion history suffices to reconstruct the growth factor of linearized density perturbations in the non-relativistic matter component on scales much smaller than the Hubble distance. In this paper, we develop a non-parametric method for extracting information about the perturbative growth factor from data pertaining to the luminosity or angular size distances. A comparison of the reconstructed density contrast with observations of large-scale structure and gravitational lensing can help distinguish DE models such as the cosmological constant and quintessence from models based on modified gravity theories as well as models in which DE and DM are either unified or interact directly. We show that for current supernovae (SNe) data, the linear growth factor at z = 0.3 can be constrained to 5% and the linear growth rate to 6%. With future SNe data, such as expected from the Joint Dark Energy Mission, we may be able to constrain the growth factor to 2%-3% and the growth rate to 3%-4% at z = 0.3 with this unbiased, model-independent reconstruction method. For future baryon acoustic oscillation data which would deliver measurements of both the angular diameter distance and the Hubble parameter, it should be possible to constrain the growth factor at z = 2.5%-9%. These constraints grow tighter with the errors on the data sets. With a large quantity of data expected in the next few years, this method can emerge as a competitive tool for distinguishing between different models of dark energy.

  20. On the vector model of angular momentum

    NASA Astrophysics Data System (ADS)

    Saari, Peeter

    2016-09-01

    Instead of (or in addition to) the common vector diagram with cones, we propose to visualize the peculiarities of quantum mechanical angular momentum by a completely quantized 3D model. It spotlights the discrete eigenvalues and noncommutativity of components of angular momentum and corresponds to outcomes of measurements—real or computer-simulated. The latter can be easily realized by an interactive worksheet of a suitable program package of algebraic calculations. The proposed complementary method of visualization helps undergraduate students to better understand the counterintuitive properties of this quantum mechanical observable.

  1. Time-resolved orbital angular momentum spectroscopy

    SciTech Connect

    Noyan, Mehmet A.; Kikkawa, James M.

    2015-07-20

    We introduce pump-probe magneto-orbital spectroscopy, wherein Laguerre-Gauss optical pump pulses impart orbital angular momentum to the electronic states of a material and subsequent dynamics are studied with 100 fs time resolution. The excitation uses vortex modes that distribute angular momentum over a macroscopic area determined by the spot size, and the optical probe studies the chiral imbalance of vortex modes reflected off the sample. First observations in bulk GaAs yield transients that evolve on time scales distinctly different from population and spin relaxation, as expected, but with surprisingly large lifetimes.

  2. Probing Angular Correlations in Sequential Double Ionization

    SciTech Connect

    Fleischer, A.; Woerner, H. J.; Arissian, L.; Liu, L. R.; Meckel, M.; Rippert, A.; Doerner, R.; Villeneuve, D. M.; Corkum, P. B.; Staudte, A.

    2011-09-09

    We study electron correlation in sequential double ionization of noble gas atoms and HCl in intense, femtosecond laser pulses. We measure the photoelectron angular distributions of Ne{sup +} relative to the first electron in a pump-probe experiment with 8 fs, 800 nm, circularly polarized laser pulses at a peak intensity of a few 10{sup 15} W/cm{sup 2}. Using a linear-linear pump-probe setup, we further study He, Ar, and HCl. We find a clear angular correlation between the two ionization steps in the sequential double ionization intensity regime.

  3. Final-state angular momentum distributions in charge transfer collisions at high energies

    NASA Astrophysics Data System (ADS)

    Burgdörfer, Joachim

    1985-11-01

    We investigate the influence of different terms of the Born series on the final-state angular momentum ( l) distribution and the anisotropy of the captured electron. A variety of different l distributions depending on the projectile velocity v and the charge asymmetry {Z p}/{Z T} of the collision system can be found, revealing different underlying mechanisms for charge transfer. We compare the predictions of perturbation theories such as the first and second Born approximation, the continuum distorted wave (CDW) approximation and the post-collision interaction (PCI) model valid at high velocities with those of the "quasi-resonant over barrier" model of charge transfer valid at intermediate velocities.

  4. Identifying Network Perturbation in Cancer

    PubMed Central

    Logsdon, Benjamin A.; Gentles, Andrew J.; Lee, Su-In

    2016-01-01

    We present a computational framework, called DISCERN (DIfferential SparsE Regulatory Network), to identify informative topological changes in gene-regulator dependence networks inferred on the basis of mRNA expression datasets within distinct biological states. DISCERN takes two expression datasets as input: an expression dataset of diseased tissues from patients with a disease of interest and another expression dataset from matching normal tissues. DISCERN estimates the extent to which each gene is perturbed—having distinct regulator connectivity in the inferred gene-regulator dependencies between the disease and normal conditions. This approach has distinct advantages over existing methods. First, DISCERN infers conditional dependencies between candidate regulators and genes, where conditional dependence relationships discriminate the evidence for direct interactions from indirect interactions more precisely than pairwise correlation. Second, DISCERN uses a new likelihood-based scoring function to alleviate concerns about accuracy of the specific edges inferred in a particular network. DISCERN identifies perturbed genes more accurately in synthetic data than existing methods to identify perturbed genes between distinct states. In expression datasets from patients with acute myeloid leukemia (AML), breast cancer and lung cancer, genes with high DISCERN scores in each cancer are enriched for known tumor drivers, genes associated with the biological processes known to be important in the disease, and genes associated with patient prognosis, in the respective cancer. Finally, we show that DISCERN can uncover potential mechanisms underlying network perturbation by explaining observed epigenomic activity patterns in cancer and normal tissue types more accurately than alternative methods, based on the available epigenomic data from the ENCODE project. PMID:27145341

  5. Perturbation analyses of intermolecular interactions.

    PubMed

    Koyama, Yohei M; Kobayashi, Tetsuya J; Ueda, Hiroki R

    2011-08-01

    Conformational fluctuations of a protein molecule are important to its function, and it is known that environmental molecules, such as water molecules, ions, and ligand molecules, significantly affect the function by changing the conformational fluctuations. However, it is difficult to systematically understand the role of environmental molecules because intermolecular interactions related to the conformational fluctuations are complicated. To identify important intermolecular interactions with regard to the conformational fluctuations, we develop herein (i) distance-independent and (ii) distance-dependent perturbation analyses of the intermolecular interactions. We show that these perturbation analyses can be realized by performing (i) a principal component analysis using conditional expectations of truncated and shifted intermolecular potential energy terms and (ii) a functional principal component analysis using products of intermolecular forces and conditional cumulative densities. We refer to these analyses as intermolecular perturbation analysis (IPA) and distance-dependent intermolecular perturbation analysis (DIPA), respectively. For comparison of the IPA and the DIPA, we apply them to the alanine dipeptide isomerization in explicit water. Although the first IPA principal components discriminate two states (the α state and PPII (polyproline II) + β states) for larger cutoff length, the separation between the PPII state and the β state is unclear in the second IPA principal components. On the other hand, in the large cutoff value, DIPA eigenvalues converge faster than that for IPA and the top two DIPA principal components clearly identify the three states. By using the DIPA biplot, the contributions of the dipeptide-water interactions to each state are analyzed systematically. Since the DIPA improves the state identification and the convergence rate with retaining distance information, we conclude that the DIPA is a more practical method compared with the

  6. Transport Studies Using Perturbative Experiments

    SciTech Connect

    Hogeweij, G.M.D.

    2004-03-15

    By inducing a small electron temperature perturbation in a plasma in steady state one can in principle determine the conductive and convective components of the electron heat ux, and the associated thermal diffusivity and convection velocity. The same can be done for other plasma parameters, like density or ion temperature.In this paper experimental and analysis techniques are briey reviewed. The fundamental question whether the uxes are linear functions of the gradients or not is discussed. Experimental results are summarized, including so-called 'non-local' phenomena.

  7. Perturbation analyses of intermolecular interactions

    NASA Astrophysics Data System (ADS)

    Koyama, Yohei M.; Kobayashi, Tetsuya J.; Ueda, Hiroki R.

    2011-08-01

    Conformational fluctuations of a protein molecule are important to its function, and it is known that environmental molecules, such as water molecules, ions, and ligand molecules, significantly affect the function by changing the conformational fluctuations. However, it is difficult to systematically understand the role of environmental molecules because intermolecular interactions related to the conformational fluctuations are complicated. To identify important intermolecular interactions with regard to the conformational fluctuations, we develop herein (i) distance-independent and (ii) distance-dependent perturbation analyses of the intermolecular interactions. We show that these perturbation analyses can be realized by performing (i) a principal component analysis using conditional expectations of truncated and shifted intermolecular potential energy terms and (ii) a functional principal component analysis using products of intermolecular forces and conditional cumulative densities. We refer to these analyses as intermolecular perturbation analysis (IPA) and distance-dependent intermolecular perturbation analysis (DIPA), respectively. For comparison of the IPA and the DIPA, we apply them to the alanine dipeptide isomerization in explicit water. Although the first IPA principal components discriminate two states (the α state and PPII (polyproline II) + β states) for larger cutoff length, the separation between the PPII state and the β state is unclear in the second IPA principal components. On the other hand, in the large cutoff value, DIPA eigenvalues converge faster than that for IPA and the top two DIPA principal components clearly identify the three states. By using the DIPA biplot, the contributions of the dipeptide-water interactions to each state are analyzed systematically. Since the DIPA improves the state identification and the convergence rate with retaining distance information, we conclude that the DIPA is a more practical method compared with the

  8. Using an open-source PACS virtual machine for a digital angiography unit: methods and initial impressions.

    PubMed

    Kagadis, George C; Alexakos, Christos; Langer, Steve G; French, Todd

    2012-02-01

    The productivity gains, diagnostic benefit, and enhanced data availability to clinicians enabled by picture archiving and communication systems (PACS) are no longer in doubt. However, commercial PACS offerings are often extremely expensive initially and require ongoing support contracts with vendors to maintain them. Recently, several open-source offerings have become available that put PACS within reach of more users. However, they can be resource-intensive to install and assure that they have room for future growth--both for computational and storage capacity. An alternate approach, which we describe herein, is to use PACS built on virtual machines which can be moved from smaller to larger hardware as needed in a just-in-time manner. This leverages the cost benefits of Moore's Law for both storage and compute costs. We describe the approach and current results in this paper.

  9. EXP-PAC: providing comparative analysis and storage of next generation gene expression data.

    PubMed

    Church, Philip C; Goscinski, Andrzej; Lefèvre, Christophe

    2012-07-01

    Microarrays and more recently RNA sequencing has led to an increase in available gene expression data. How to manage and store this data is becoming a key issue. In response we have developed EXP-PAC, a web based software package for storage, management and analysis of gene expression and sequence data. Unique to this package is SQL based querying of gene expression data sets, distributed normalization of raw gene expression data and analysis of gene expression data across experiments and species. This package has been populated with lactation data in the international milk genomic consortium web portal (http://milkgenomics.org/). Source code is also available which can be hosted on a Windows, Linux or Mac APACHE server connected to a private or public network (http://mamsap.it.deakin.edu.au/~pcc/Release/EXP_PAC.html).

  10. Personality and personal projects: linking big five and PAC units of analysis.

    PubMed

    Little, B R; Lecci, L; Watkinson, B

    1992-06-01

    This article examines the relationships between classical trait units as represented by the five-factor model (e.g., Digman, 1990) and personal action construct (PAC) units as measured by Personal Projects Analysis (Little, 1983). One hundred and forty-seven students were administered the NEO Personality Inventory (Costa & McCrae, 1985) and two components of Personal Projects methodology during their first term in university. Neuroticism and Conscientiousness were related to problematic and positive project systems, respectively, with these effects generalizing across the academic and interpersonal project domains. Extraversion and Agreeableness were also associated with positive evaluations of personal projects, particularly in the interpersonal domain. Openness was distinctively linked with project initiation and value congruency. We suggest theoretical and applied implications of using PAC methods to expand and refine the classical trait research agenda.

  11. The Herschel PACS Pipeline Extensions: Making Tasks and Scripts Suitable for Interactive and Automatic Processing

    NASA Astrophysics Data System (ADS)

    de Jong, J. A.; Wieprecht, E.; Schreiber, J.; Huygen, R.; Wetzstein, M.; Royer, P.; Vandenbussche, B.; Exter, K.; Vavrek, R.; Gonzalez, B.; Diaz, J.; Bakker, J.; Sturm, E.

    2012-09-01

    We present some extensions which were added to the Herschel Common Software System (HCSS) for processing and analyzing observations of the PACS instrument (Poglitsch et al. 2010) on the Herschel Space Observatory (Pilbratt et al. 2010). PACS users and developers worked closely together to improve the user experience when interactively analyzing observations, in such a way that user friendly scripts can be shared with the pipeline for systematic processing. In this way we can easily keep the pipeline up-to-date with user contributed improvements. The most important goals of these improvements are: (1) Hide all the administrative work done in pipeline tasks (such as handling meta data) from the user; (2) Make sure that all tasks can be run step-by-step, even if loops over several products are needed (such loops are all hidden inside the pipeline tasks); (3) Provide convenience tools to deal with observations which are split into many parts (which we call slices).

  12. Development of Cryogenic Filter Wheels for the HERSCHEL Photodetector Array Camera & Spectrometer (PACS)

    NASA Technical Reports Server (NTRS)

    Koerner, Christian; Kampf, Dirk; Poglitsch, Albrecht; Schubert, Josef; Ruppert, U.; Schoele, M.

    2014-01-01

    This paper describes the two PACS Filter Wheels that are direct-drive rotational mechanisms operated at a temperature below 5K inside the PACS focal plane unit of the Herschel Satellite. The purpose of the mechanisms is to switch between filters. The rotation axis is pivoted to the support structure via a slightly preloaded pair of ball bearings and driven by a Cryotorquer. Position sensing is realized by a pair of Hall effect sensors. Powerless positioning at the filter positions is achieved by a magnetic ratchet system. The key technologies are the Cryotorquer design and the magnetic ratchet design in the low temperature range. Furthermore, we will report on lessons learned during the development and qualification of the mechanism and the paint.

  13. Budget variance analysis of a departmentwide implementation of a PACS at a major academic medical center.

    PubMed

    Reddy, Arra Suresh; Loh, Shaun; Kane, Robert A

    2006-01-01

    In this study, the costs and cost savings associated with departmentwide implementation of a picture archiving and communication system (PACS) as compared to the projected budget at the time of inception were evaluated. An average of $214,460 was saved each year with a total savings of $1,072,300 from 1999 to 2003, which is significantly less than the $2,943,750 projected savings. This discrepancy can be attributed to four different factors: (1) overexpenditures, (2) insufficient cost savings, (3) unanticipated costs, and (4) project management issues. Although the implementation of PACS leads to cost savings, actual savings will be much lower than expected unless extraordinary care is taken when devising the budget. PMID:16946989

  14. Necessary security mechanisms in a PACS DICOM access system with web technology.

    PubMed

    Vázquez-Naya, José; Loureiro, Javier; Calle, Julián; Vidal, Jorge; Sierra, Alejandro

    2002-01-01

    The evolution in information and telecommunication technologies has allowed the development of systems that use the Internet infrastructure and Web technology to remotely access a hospital's picture archiving and communication system (PACS). However, one of the main problems in the construction of this type of system is the development of mechanisms that guarantee the security of the medical data that are being consulted. Most countries have specific norms for the protection of such medical data. This work describes security mechanisms that are developed in an access system to PACS DICOM with Web technology and comply with the Spanish legislation concerning the protection of medical data. The proposed security mechanisms are flexible, they leave room for the definition of security policies adjusted to the needs of each particular organization and they can be adapted to comply with new or foreign norms.

  15. ANGULAR MOMENTUM ACQUISITION IN GALAXY HALOS

    SciTech Connect

    Stewart, Kyle R.; Brooks, Alyson M.; Bullock, James S.; Maller, Ariyeh H.; Diemand, Juerg; Wadsley, James; Moustakas, Leonidas A.

    2013-05-20

    We use high-resolution cosmological hydrodynamic simulations to study the angular momentum acquisition of gaseous halos around Milky-Way-sized galaxies. We find that cold mode accreted gas enters a galaxy halo with {approx}70% more specific angular momentum than dark matter averaged over cosmic time (though with a very large dispersion). In fact, we find that all matter has a higher spin parameter when measured at accretion than when averaged over the entire halo lifetime, and is well characterized by {lambda} {approx} 0.1, at accretion. Combined with the fact that cold flow gas spends a relatively short time (1-2 dynamical times) in the halo before sinking to the center, this naturally explains why cold flow halo gas has a specific angular momentum much higher than that of the halo and often forms ''cold flow disks.'' We demonstrate that the higher angular momentum of cold flow gas is related to the fact that it tends to be accreted along filaments.

  16. A Novel Permanent Magnetic Angular Acceleration Sensor.

    PubMed

    Zhao, Hao; Feng, Hao

    2015-07-03

    Angular acceleration is an important parameter for status monitoring and fault diagnosis of rotary machinery. Therefore, we developed a novel permanent magnetic angular acceleration sensor, which is without rotation angle limitations and could directly measure the instantaneous angular acceleration of the rotating system. The sensor rotor only needs to be coaxially connected with the rotating system, which enables convenient sensor installation. For the cup structure of the sensor rotor, it has a relatively small rotational inertia. Due to the unique mechanical structure of the sensor, the output signal of the sensor can be directed without a slip ring, which avoids signal weakening effect. In this paper, the operating principle of the sensor is described, and simulated using finite element method. The sensitivity of the sensor is calibrated by torsional pendulum and angle sensor, yielding an experimental result of about 0.88 mV/(rad·s(-2)). Finally, the angular acceleration of the actual rotating system has been tested, using both a single-phase asynchronous motor and a step motor. Experimental result confirms the operating principle of the sensor and indicates that the sensor has good practicability.

  17. A Novel Permanent Magnetic Angular Acceleration Sensor

    PubMed Central

    Zhao, Hao; Feng, Hao

    2015-01-01

    Angular acceleration is an important parameter for status monitoring and fault diagnosis of rotary machinery. Therefore, we developed a novel permanent magnetic angular acceleration sensor, which is without rotation angle limitations and could directly measure the instantaneous angular acceleration of the rotating system. The sensor rotor only needs to be coaxially connected with the rotating system, which enables convenient sensor installation. For the cup structure of the sensor rotor, it has a relatively small rotational inertia. Due to the unique mechanical structure of the sensor, the output signal of the sensor can be directed without a slip ring, which avoids signal weakening effect. In this paper, the operating principle of the sensor is described, and simulated using finite element method. The sensitivity of the sensor is calibrated by torsional pendulum and angle sensor, yielding an experimental result of about 0.88 mV/(rad·s−2). Finally, the angular acceleration of the actual rotating system has been tested, using both a single-phase asynchronous motor and a step motor. Experimental result confirms the operating principle of the sensor and indicates that the sensor has good practicability. PMID:26151217

  18. Heteromodal conceptual processing in the angular gyrus

    PubMed Central

    Bonner, Michael F.; Peelle, Jonathan E.; Cook, Philip A.; Grossman, Murray

    2013-01-01

    Concepts bind together the features commonly associated with objects and events to form networks in long-term semantic memory. These conceptual networks are the basis of human knowledge and underlie perception, imagination, and the ability to communicate about experiences and the contents of the environment. Although it is often assumed that this distributed semantic information is integrated in higher-level heteromodal association cortices, open questions remain about the role and anatomic basis of heteromodal representations in semantic memory. Here we used combined neuroimaging evidence from functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to characterize the cortical networks underlying concept representation. Using a lexical decision task, we examined the processing of concepts in four semantic categories that varied on their sensory-motor feature associations (sight, sound, manipulation, and abstract). We found that the angular gyrus was activated across all categories regardless of their modality-specific feature associations, consistent with a heteromodal account for the angular gyrus. Exploratory analyses suggested that categories with weighted sensory-motor features additionally recruited modality-specific association cortices. Furthermore, DTI tractography identified white matter tracts connecting these regions of modality-specific functional activation with the angular gyrus. These findings are consistent with a distributed semantic network that includes a heteromodal, integrative component in the angular gyrus in combination with sensory-motor feature representations in modality-specific association cortices. PMID:23333416

  19. Critical gravitational collapse with angular momentum

    NASA Astrophysics Data System (ADS)

    Gundlach, Carsten; Baumgarte, Thomas W.

    2016-10-01

    We derive a theoretical model of mass and angular momentum scaling in type-II critical collapse with rotation. We focus on the case where the critical solution has precisely one, spherically symmetric, unstable mode. We demonstrate agreement with numerical results for critical collapse of a rotating radiation fluid, which falls into this case.

  20. Inclusion of angular momentum in FREYA

    DOE PAGESBeta

    Randrup, Jørgen; Vogt, Ramona

    2015-05-18

    The event-by-event fission model FREYA generates large samples of complete fission events from which any observable can extracted, including fluctuations of the observables and the correlations between them. We describe here how FREYA was recently refined to include angular momentum throughout. Subsequently we present some recent results for both neutron and photon observables.

  1. "Phonon" scattering beyond perturbation theory

    NASA Astrophysics Data System (ADS)

    Qiu, WuJie; Ke, XueZhi; Xi, LiLi; Wu, LiHua; Yang, Jiong; Zhang, WenQing

    2016-02-01

    Searching and designing materials with intrinsically low lattice thermal conductivity (LTC) have attracted extensive consideration in thermoelectrics and thermal management community. The concept of part-crystalline part-liquid state, or even part-crystalline part-amorphous state, has recently been proposed to describe the exotic structure of materials with chemical- bond hierarchy, in which a set of atoms is weakly bonded to the rest species while the other sublattices retain relatively strong rigidity. The whole system inherently manifests the coexistence of rigid crystalline sublattices and fluctuating noncrystalline substructures. Representative materials in the unusual state can be classified into two categories, i.e., caged and non-caged ones. LTCs in both systems deviate from the traditional T -1 relationship ( T, the absolute temperature), which can hardly be described by small-parameter-based perturbation approaches. Beyond the classical perturbation theory, an extra rattling-like scattering should be considered to interpret the liquid-like and sublattice-amorphization-induced heat transport. Such a kind of compounds could be promising high-performance thermoelectric materials, due to the extremely low LTCs. Other physical properties for these part-crystalline substances should also exhibit certain novelty and deserve further exploration.

  2. Genome Sequence of Bradyrhizobium pachyrhizi Strain PAC48T, a Nitrogen-Fixing Symbiont of Pachyrhizus erosus (L.) Urb.

    PubMed

    Delamuta, Jakeline Renata Marçon; Ribeiro, Renan Augusto; Gomes, Douglas Fabiano; Souza, Renata Carolina; Chueire, Ligia Maria Oliveira; Hungria, Mariangela

    2015-01-01

    Bradyrhizobium pachyrhizi PAC48(T) has been isolated from a jicama nodule in Costa Rica. The draft genome indicates high similarity with that of Bradyrhizobium elkanii. Several coding sequences (CDSs) of the stress response might help in survival in the tropics. PAC48(T) carries nodD1 and nodK, similar to Bradyrhizobium (Parasponia) ANU 289 and a particular nodD2 gene. PMID:26383651

  3. Genome Sequence of Bradyrhizobium pachyrhizi Strain PAC48T, a Nitrogen-Fixing Symbiont of Pachyrhizus erosus (L.) Urb.

    PubMed Central

    Delamuta, Jakeline Renata Marçon; Ribeiro, Renan Augusto; Gomes, Douglas Fabiano; Souza, Renata Carolina; Chueire, Ligia Maria Oliveira

    2015-01-01

    Bradyrhizobium pachyrhizi PAC48T has been isolated from a jicama nodule in Costa Rica. The draft genome indicates high similarity with that of Bradyrhizobium elkanii. Several coding sequences (CDSs) of the stress response might help in survival in the tropics. PAC48T carries nodD1 and nodK, similar to Bradyrhizobium (Parasponia) ANU 289 and a particular nodD2 gene. PMID:26383651

  4. Should allocation of functions between HIS/RIS and PACS be standardized?

    NASA Astrophysics Data System (ADS)

    Toussaint, Pieter J.; Ottes, Fenno P.; Bakker, Albert R.

    1994-05-01

    In the field of (medical) electronic data interchange a lot of `standards' or `protocols' are developed in order to make interchange work in a multi-vendor environment. These standards range from providing guidelines for a file format, to specifying possible dialogues between systems. Which standard to choose among the candidates, depends on the purpose it is used for. In the case of HIS/RIS and PACS integration a fullfledged communication protocol is needed.

  5. Redshift-space distortions with wide angular separations

    SciTech Connect

    Reimberg, Paulo; Bernardeau, Francis; Pitrou, Cyril E-mail: francis.bernardeau@cea.fr

    2016-01-01

    Redshift-space distortions are generally considered in the plane parallel limit, where the angular separation between the two sources can be neglected. Given that galaxy catalogues now cover large fractions of the sky, it becomes necessary to consider them in a formalism which takes into account the wide angle separations. In this article we derive an operational formula for the matter correlators in the Newtonian limit to be used in actual data sets. In order to describe the geometrical nature of the wide angle RSD effect on Fourier space, we extend the formalism developed in configuration space to Fourier space without relying on a plane-parallel approximation, but under the extra assumption of no bias evolution. We then recover the plane-parallel limit not only in configuration space where the geometry is simpler, but also in Fourier space, and we exhibit the first corrections that should be included in large surveys as a perturbative expansion over the plane-parallel results. We finally compare our results to existing literature, and show explicitly how they are related.

  6. Perturbative Methods in Path Integration

    NASA Astrophysics Data System (ADS)

    Johnson-Freyd, Theodore Paul

    This dissertation addresses a number of related questions concerning perturbative "path" integrals. Perturbative methods are one of the few successful ways physicists have worked with (or even defined) these infinite-dimensional integrals, and it is important as mathematicians to check that they are correct. Chapter 0 provides a detailed introduction. We take a classical approach to path integrals in Chapter 1. Following standard arguments, we posit a Feynman-diagrammatic description of the asymptotics of the time-evolution operator for the quantum mechanics of a charged particle moving nonrelativistically through a curved manifold under the influence of an external electromagnetic field. We check that our sum of Feynman diagrams has all desired properties: it is coordinate-independent and well-defined without ultraviolet divergences, it satisfies the correct composition law, and it satisfies Schrodinger's equation thought of as a boundary-value problem in PDE. Path integrals in quantum mechanics and elsewhere in quantum field theory are almost always of the shape ∫ f es for some functions f (the "observable") and s (the "action"). In Chapter 2 we step back to analyze integrals of this type more generally. Integration by parts provides algebraic relations between the values of ∫ (-) es for different inputs, which can be packaged into a Batalin--Vilkovisky-type chain complex. Using some simple homological perturbation theory, we study the version of this complex that arises when f and s are taken to be polynomial functions, and power series are banished. We find that in such cases, the entire scheme-theoretic critical locus (complex points included) of s plays an important role, and that one can uniformly (but noncanonically) integrate out in a purely algebraic way the contributions to the integral from all "higher modes," reducing ∫ f es to an integral over the critical locus. This may help explain the presence of analytic continuation in questions like the

  7. Photoactivated adenylyl cyclase (PAC) reveals novel mechanisms underlying cAMP-dependent axonal morphogenesis

    PubMed Central

    Zhou, Zhiwen; Tanaka, Kenji F.; Matsunaga, Shigeru; Iseki, Mineo; Watanabe, Masakatsu; Matsuki, Norio; Ikegaya, Yuji; Koyama, Ryuta

    2016-01-01

    Spatiotemporal regulation of axonal branching and elongation is essential in the development of refined neural circuits. cAMP is a key regulator of axonal growth; however, whether and how intracellular cAMP regulates axonal branching and elongation remain unclear, mainly because tools to spatiotemporally manipulate intracellular cAMP levels have been lacking. To overcome this issue, we utilized photoactivated adenylyl cyclase (PAC), which produces cAMP in response to blue-light exposure. In primary cultures of dentate granule cells transfected with PAC, short-term elevation of intracellular cAMP levels induced axonal branching but not elongation, whereas long-term cAMP elevation induced both axonal branching and elongation. The temporal dynamics of intracellular cAMP levels regulated axonal branching and elongation through the activation of protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac), respectively. Thus, using PAC, our study for the first time reveals that temporal cAMP dynamics could regulate axonal branching and elongation via different signaling pathways. PMID:26795422

  8. PACAP38/PAC1 Signaling Induces Bone Marrow-Derived Cells Homing to Ischemic Brain

    PubMed Central

    Lin, Chen-Huan; Chiu, Lian; Lee, Hsu-Tung; Chiang, Chun-Wei; Liu, Shih-Ping; Hsu, Yung-Hsiang; Lin, Shinn-Zong; Hsu, Chung Y; Hsieh, Chia-Hung; Shyu, Woei-Cherng

    2015-01-01

    Understanding stem cell homing, which is governed by environmental signals from the surrounding niche, is important for developing effective stem cell-based repair strategies. The molecular mechanism by which the brain under ischemic stress recruits bone marrow-derived cells (BMDCs) to the vascular niche remains poorly characterized. Here we report that hypoxia-inducible factor-1α (HIF-1α) activation upregulates pituitary adenylate cyclase-activating peptide 38 (PACAP38), which in turn activates PACAP type 1 receptor (PAC1) under hypoxia in vitro and cerebral ischemia in vivo. BMDCs homing to endothelial cells in the ischemic brain are mediated by HIF-1α activation of the PACAP38-PAC1 signaling cascade followed by upregulation of cellular prion protein and α6-integrin to enhance the ability of BMDCs to bind laminin in the vascular niche. Exogenous PACAP38 confers a similar effect in facilitating BMDCs homing into the ischemic brain, resulting in reduction of ischemic brain injury. These findings suggest a novel HIF-1α-activated PACAP38-PAC1 signaling process in initiating BMDCs homing into the ischemic brain for reducing brain injury and enhancing functional recovery after ischemic stroke. Stem Cells 2015;33:1153–1172 PMID:25523790

  9. Effective Reuse of Electroplating Rinse Wastewater by Combining PAC with H2O2/UV Process.

    PubMed

    Yen, Hsing Yuan; Kang, Shyh-Fang; Lin, Chen Pei

    2015-04-01

    This study evaluated the performance of treating electroplating rinse wastewater by powder activated carbon (PAC) adsorption, H2O2/UV oxidation, and their combination to remove organic compounds and heavy metals. The results showed that neither the process of PAC adsorption nor H2O2/UV oxidation could reduce COD to 100 mg/L, as enforced by the Taiwan Environmental Protection Agency. On the other hand, the water sample treated by the combined approach of using PAC (5 g/L) pre-adsorption and H2O2/UV post-oxidation (UV of 64 W, H2O2 of 100 mg/L, oxidation time of 90 min), COD and DOC were reduced to 8.2 mg/L and 3.8 mg/L, respectively. Also, the combined approach reduced heavy metals to meet the effluent standards and to satisfy the in-house water reuse criteria for the electroplating factory. The reaction constant analysis indicated that the reaction proceeded much more rapidly for the combined process. Hence, it is a more efficient, economic and environmentally friendly process.

  10. A remote real-time PACS-based platform for medical imaging telemedicine

    NASA Astrophysics Data System (ADS)

    Maani, Rouzbeh; Camorlinga, Sergio; Eskicioglu, Rasit

    2009-02-01

    This paper describes a remote real-time PACS-based telemedicine platform for clinical and diagnostic services delivered at different care settings where the physicians, specialists and scientists may attend. In fact, the platform aims to provide a PACS-based telemedicine framework for different medical image services such as segmentation, registration and specifically high-quality 3D visualization. The proposed approach offers services which are not only widely accessible and real-time, but are also secure and cost-effective. In addition, the proposed platform has the ability to bring in a realtime, ubiquitous, collaborative, interactive meeting environment supporting 3D visualization for consultations, which has not been well addressed with the current PACS-based applications. Using this ability, physicians and specialists can consult with each other at separate places and it is especially helpful for settings, where there is no specialist or the number of specialists is not enough to handle all the available cases. Furthermore, the proposed platform can be used as a rich resource for clinical research studies as well as for academic purposes.

  11. Bibliographic database of PACS-related articles from the SPIE literature

    NASA Astrophysics Data System (ADS)

    Shile, Peter E.; Freiermuth, Jennifer

    1996-05-01

    Publications of the International Society of Optical Engineering (SPIE) contain much of the relevant literature on Picture Archiving and Communications Systems (PACS) and related topics. In fact, many PACS-related articles indexed by the National Library of Medicine contain references to articles published by SPIE. Unfortunately, SPIE publications themselves are not indexed by the National Library of Medicine and thus can not be identified through Medline. The lack of a convenient mechanism for searching the SPIE literature is problematic for researchers in medical imaging. With the recent introduction on SPIE's Internet server of their Abstracts Online service and their In-CiteTM title and author searching software, the SPIE literature has become more accessible. However, the searching process is still a cumbersome and time consuming process, and it is not possible to perform key word searches of manuscript abstracts. In this paper we present results of our work on developing a mechanism to more thoroughly search SPIE publications for PACS-related articles.

  12. Java-Based Astronomical Software - The HERSCHEL/ PACS Common Software System as Example

    NASA Astrophysics Data System (ADS)

    Wieprecht, E.; Huygen, R.; Vandenbussche, B.; De Meester, W.; Guest, S.; de Jonge, A.; Zaal, P.; Osterhage, S.; Wetzstein, M.

    2005-12-01

    ESA's Herschel Space Observatory, planned to be launched in 2007, is the first space observatory covering the full far-infrared and submillimetre wavelength range (60 - 670 microns). The Photodetector Array Camera and Spectrometer (PACS) is one of its three science instruments. It employs two Ge:Ga photoconductor arrays and two bolometer arrays to perform imaging line spectroscopy and imaging photometry in the 60 - 210 micron wavelength band. The HERSCHEL Common Software System (HCSS) forms the base of the HERSCHEL ground segment. HCSS is implemented using JAVA/Jython technology and interacts with an object oriented database. It is written in a common effort by the HERSCHEL Science Centre and the three instrument teams. The PACS Common Software System (PCSS) is based on the HCSS. Both systems were designed for a smooth transition between the different phases of the project. Instrument engineers use PCSS during instrument tests, calibration specialists for instrument characterization on ground and in orbit, and finally the observer will use it for data reduction. The design allows use of the same components for automatic processing, quick look analysis, and interactive processing. We outline some design aspects of such a highly complex system and present user experiences with PCSS, gathered during first instrument tests of PACS.

  13. Photoactivated adenylyl cyclase (PAC) reveals novel mechanisms underlying cAMP-dependent axonal morphogenesis.

    PubMed

    Zhou, Zhiwen; Tanaka, Kenji F; Matsunaga, Shigeru; Iseki, Mineo; Watanabe, Masakatsu; Matsuki, Norio; Ikegaya, Yuji; Koyama, Ryuta

    2016-01-01

    Spatiotemporal regulation of axonal branching and elongation is essential in the development of refined neural circuits. cAMP is a key regulator of axonal growth; however, whether and how intracellular cAMP regulates axonal branching and elongation remain unclear, mainly because tools to spatiotemporally manipulate intracellular cAMP levels have been lacking. To overcome this issue, we utilized photoactivated adenylyl cyclase (PAC), which produces cAMP in response to blue-light exposure. In primary cultures of dentate granule cells transfected with PAC, short-term elevation of intracellular cAMP levels induced axonal branching but not elongation, whereas long-term cAMP elevation induced both axonal branching and elongation. The temporal dynamics of intracellular cAMP levels regulated axonal branching and elongation through the activation of protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac), respectively. Thus, using PAC, our study for the first time reveals that temporal cAMP dynamics could regulate axonal branching and elongation via different signaling pathways. PMID:26795422

  14. Integration in PACS of DICOM with TCP/IP, SQL, and X Windows

    NASA Astrophysics Data System (ADS)

    Reijns, Gerard L.

    1994-05-01

    The DICOM standard (Digital Imaging and Communications in Medicine) has been developed in order to obtain compatibility at the higher OSI levels. This paper describes the implementation of DICOM into our developed low cost PACS, which uses as much as possible standard software and standard protocols such as SQL, X Windows and TCP/IP. We adopted the requirement that all messages on the communication network have to be DICOM compatible. The translation between DICOM messages and SQL commands, which drive the relational data base, has been accommodated in our PACS supervisor. The translation takes only between 10 and 20 milliseconds. Images, that will be used the current day are stored in a distributed, parallel operating image base for reasons of performance. Extensive use has been made of X Windows to visualize images. A maximum of 12 images can simultaneously be displayed, of which one selected image can be manipulated (e.g., magnified, rotated, etc.), without affecting the other displayed images. The emphasis of the future work will be on performance measurements and modeling of our PACS and bringing the results of both methods in agreement with each other.

  15. Integration of a multimedia teaching and reference database in a PACS environment.

    PubMed

    Rosset, Antoine; Ratib, Osman; Geissbuhler, Antoine; Vallée, Jean-Paul

    2002-01-01

    In one radiology department, a computerized authoring and editing environment was developed and integrated with the picture archiving and communication systems (PACS) for creation of image-based electronic teaching files to replace a collection of printed film images. This multimedia database and authoring environment allows physicians to create reference databases for teaching and research directly from clinical cases being reviewed on PACS diagnostic workstations. The database engine allows users to generate stand-alone CD-ROMs (compact disks, read-only memory) and World Wide Web-based teaching files. The system is fully compliant with the Digital Imaging and Communications in Medicine (DICOM) standard and supports a large number of standard multimedia image file formats. The focus of the development was on convenience and ease of use of a generic system adaptable to all users. The software was integrated on the PACS workstations to allow users to add new cases to the database at any time and anywhere in the department. A pilot system was implemented in clinical operation, with a central server and several client units. PMID:12432130

  16. Discovering Multimodal Behavior in Ms. Pac-Man through Evolution of Modular Neural Networks

    PubMed Central

    Schrum, Jacob; Miikkulainen, Risto

    2015-01-01

    Ms. Pac-Man is a challenging video game in which multiple modes of behavior are required: Ms. Pac-Man must escape ghosts when they are threats and catch them when they are edible, in addition to eating all pills in each level. Past approaches to learning behavior in Ms. Pac-Man have treated the game as a single task to be learned using monolithic policy representations. In contrast, this paper uses a framework called Modular Multi-objective NEAT (MM-NEAT) to evolve modular neural networks. Each module defines a separate behavior. The modules are used at different times according to a policy that can be human-designed (i.e. Multitask) or discovered automatically by evolution. The appropriate number of modules can be fixed or discovered using a genetic operator called Module Mutation. Several versions of Module Mutation are evaluated in this paper. Both fixed modular networks and Module Mutation networks outperform monolithic networks and Multitask networks. Interestingly, the best networks dedicate modules to critical behaviors (such as escaping when surrounded after luring ghosts near a power pill) that do not follow the customary division of the game into chasing edible and escaping threat ghosts. The results demonstrate that MM-NEAT can discover interesting and effective behavior for agents in challenging games. PMID:27030803

  17. HERSCHEL PACS OBSERVATIONS AND MODELING OF DEBRIS DISKS IN THE TUCANA-HOROLOGIUM ASSOCIATION

    SciTech Connect

    Donaldson, J. K.; Roberge, A.; Chen, C. H.; Augereau, J.-C.; Menard, F.; Eiroa, C.; Meeus, G.; Krivov, A. V.; Mathews, G. S.; Riviere-Marichalar, P.; Sandell, G.

    2012-07-10

    We present Herschel PACS photometry of 17 B- to M-type stars in the 30 Myr old Tucana-Horologium Association. This work is part of the Herschel Open Time Key Programme 'Gas in Protoplanetary Systems'. 6 of the 17 targets were found to have infrared excesses significantly greater than the expected stellar IR fluxes, including a previously unknown disk around HD30051. These six debris disks were fitted with single-temperature blackbody models to estimate the temperatures and abundances of the dust in the systems. For the five stars that show excess emission in the Herschel PACS photometry and also have Spitzer IRS spectra, we fit the data with models of optically thin debris disks with realistic grain properties in order to better estimate the disk parameters. The model is determined by a set of six parameters: surface density index, grain size distribution index, minimum and maximum grain sizes, and the inner and outer radii of the disk. The best-fitting parameters give us constraints on the geometry of the dust in these systems, as well as lower limits to the total dust masses. The HD105 disk was further constrained by fitting marginally resolved PACS 70 {mu}m imaging.

  18. Development of computer-aided functions in clinical neurosurgery with PACS

    NASA Astrophysics Data System (ADS)

    Mukasa, Minoru; Aoki, Makoto; Satoh, Minoru; Kowada, Masayoshi; Kikuchi, K.

    1991-07-01

    The introduction of the "Picture Archiving and Communications System (known as PACS)," provides many benefits, including the application of C.A.D., (Computer Aided Diagnosis). Clinically, this allows for the measurement and design of an operation to be easily completed with the CRT monitors of PACS rather than with film, as has been customary in the past. Under the leadership of the Department of Neurosurgery, Akita University School of Medicine, and Southern Tohoku Research Institute for Neuroscience, Koriyama, new computer aided functions with EFPACS (Fuji Electric's PACS) have been developed for use in clinical neurosurgery. This image processing is composed of three parts as follows: (1) Automatic mapping of small lesions depicted on Magnetic Resonance (or MR) images on the brain atlas. (2) Superimposition of two angiographic films onto a single synthesized image. (3) Automatic mapping of the lesion's position (as shown on the. CT images) on the processing image referred to in the foregoing clause 2. The processing in the clause (1) provides a reference for anatomical estimation. The processing in the clause (2) is used for general analysis of the condition of a disease. The processing in the clause (3) is used to design the operation. This image processing is currently being used with good results.

  19. Effect of process variables and natural organic matter on removal of microcystin-LR by PAC-UF.

    PubMed

    Lee, Jungju; Walker, Harold W

    2006-12-01

    The release of cyanobacterial toxins, such as microcystin-LR, in drinking water supplies is of increasing concern. In this study, we investigated the use of ultrafiltration (UF) combined with adsorption on powdered activated carbon (PAC) for the removal of microcystin-LR from drinking water. Process variables examined included PAC type, PAC dosage, membrane characteristics (material and pore size), and the presence of natural organic matter (NOM). Due to greater mesopore volume, wood-based activated carbon was up to 4-times more effective at removing microcystin-LR than coconut-based carbon, depending on contact time. Cellulose acetate (CA) membranes with a molecular weight cutoff (MWCO) of 20,000 Da did not reject or adsorb microcystin-LR. Membranes composed of polyethersulfone (PES) of similar pore size, on the other hand, adsorbed microcystin-LR presumably through hydrophobic interactions. A PES membrane with a MWCO of 5000 Da sorbed microcystin-LR, and also rejected 8.4% of the toxin through a size exclusion mechanism. When PAC was coupled to UF using PES membranes, greater removal of microcystin-LR occurred compared to when CA membranes were used due to sorption of the toxin to the PES membrane surface. The presence of Suwannee River fulvic acid (SRFA) reduced microcystin-LR removal by PAC-UF, primarily due to competition between SRFA and microcystin-LR for sites on the PAC surface.

  20. The dynein cortical anchor Num1 activates dynein motility by relieving Pac1/LIS1-mediated inhibition

    PubMed Central

    Lammers, Lindsay G.

    2015-01-01

    Cortically anchored dynein orients the spindle through interactions with astral microtubules. In budding yeast, dynein is offloaded to Num1 receptors from microtubule plus ends. Rather than walking toward minus ends, dynein remains associated with plus ends due in part to its association with Pac1/LIS1, an inhibitor of dynein motility. The mechanism by which dynein is switched from “off” at the plus ends to “on” at the cell cortex remains unknown. Here, we show that overexpression of the coiled-coil domain of Num1 specifically depletes dynein–dynactin–Pac1/LIS1 complexes from microtubule plus ends and reduces dynein-Pac1/LIS1 colocalization. Depletion of dynein from plus ends requires its microtubule-binding domain, suggesting that motility is required. An enhanced Pac1/LIS1 affinity mutant of dynein or overexpression of Pac1/LIS1 rescues dynein plus end depletion. Live-cell imaging reveals minus end–directed dynein–dynactin motility along microtubules upon overexpression of the coiled-coil domain of Num1, an event that is not observed in wild-type cells. Our findings indicate that dynein activity is directly switched “on” by Num1, which induces Pac1/LIS1 removal. PMID:26483554

  1. Improving the performance of an aerobic membrane bioreactor (MBR) treating pharmaceutical wastewater with powdered activated carbon (PAC) addition.

    PubMed

    Kaya, Yasemin; Bacaksiz, A Murat; Golebatmaz, Ugur; Vergili, Ilda; Gönder, Z Beril; Yilmaz, Gulsum

    2016-04-01

    In this study, the effects of organic loading rate (OLR) and the addition of powdered activated carbon (PAC) on the performance and membrane fouling of MBR were conducted to treat real pharmaceutical process wastewater. Over 145 days of operation, the MBR system was operated at OLRs ranging from 1 to 2 kg COD m(-3) day(-1) without sludge wasting. The addition of PAC provided an improvement in the flux, despite an increase in the OLR:PAC ratio. The results demonstrated that the hybrid PAC-MBR system maintained a reduced amount of membrane fouling and steadily increased the removal performance of etodolac. PAC addition reduced the deposition of extracellular polymeric substance and organic matter on the membrane surface and resulted an increase in COD removal even at higher OLRs with low PAC addition. Membrane fouling mechanisms were investigated using combined adsorption fouling models. Modified fouling index values and normalized mass transfer coefficient values indicated that predominant fouling mechanism was cake adsorption. PMID:26846538

  2. The dynein cortical anchor Num1 activates dynein motility by relieving Pac1/LIS1-mediated inhibition.

    PubMed

    Lammers, Lindsay G; Markus, Steven M

    2015-10-26

    Cortically anchored dynein orients the spindle through interactions with astral microtubules. In budding yeast, dynein is offloaded to Num1 receptors from microtubule plus ends. Rather than walking toward minus ends, dynein remains associated with plus ends due in part to its association with Pac1/LIS1, an inhibitor of dynein motility. The mechanism by which dynein is switched from "off" at the plus ends to "on" at the cell cortex remains unknown. Here, we show that overexpression of the coiled-coil domain of Num1 specifically depletes dynein-dynactin-Pac1/LIS1 complexes from microtubule plus ends and reduces dynein-Pac1/LIS1 colocalization. Depletion of dynein from plus ends requires its microtubule-binding domain, suggesting that motility is required. An enhanced Pac1/LIS1 affinity mutant of dynein or overexpression of Pac1/LIS1 rescues dynein plus end depletion. Live-cell imaging reveals minus end-directed dynein-dynactin motility along microtubules upon overexpression of the coiled-coil domain of Num1, an event that is not observed in wild-type cells. Our findings indicate that dynein activity is directly switched "on" by Num1, which induces Pac1/LIS1 removal. PMID:26483554

  3. The dynein cortical anchor Num1 activates dynein motility by relieving Pac1/LIS1-mediated inhibition.

    PubMed

    Lammers, Lindsay G; Markus, Steven M

    2015-10-26

    Cortically anchored dynein orients the spindle through interactions with astral microtubules. In budding yeast, dynein is offloaded to Num1 receptors from microtubule plus ends. Rather than walking toward minus ends, dynein remains associated with plus ends due in part to its association with Pac1/LIS1, an inhibitor of dynein motility. The mechanism by which dynein is switched from "off" at the plus ends to "on" at the cell cortex remains unknown. Here, we show that overexpression of the coiled-coil domain of Num1 specifically depletes dynein-dynactin-Pac1/LIS1 complexes from microtubule plus ends and reduces dynein-Pac1/LIS1 colocalization. Depletion of dynein from plus ends requires its microtubule-binding domain, suggesting that motility is required. An enhanced Pac1/LIS1 affinity mutant of dynein or overexpression of Pac1/LIS1 rescues dynein plus end depletion. Live-cell imaging reveals minus end-directed dynein-dynactin motility along microtubules upon overexpression of the coiled-coil domain of Num1, an event that is not observed in wild-type cells. Our findings indicate that dynein activity is directly switched "on" by Num1, which induces Pac1/LIS1 removal.

  4. Handling qualities of a wide-body transport airplane utilizing Pitch Active Control Systems (PACS) for relaxed static stability application

    NASA Technical Reports Server (NTRS)

    Grantham, William D.; Person, Lee H., Jr.; Brown, Philip W.; Becker, Lawrence E.; Hunt, George E.; Rising, J. J.; Davis, W. J.; Willey, C. S.; Weaver, W. A.; Cokeley, R.

    1985-01-01

    Piloted simulation studies have been conducted to evaluate the effectiveness of two pitch active control systems (PACS) on the flying qualities of a wide-body transport airplane when operating at negative static margins. These two pitch active control systems consisted of a simple 'near-term' PACS and a more complex 'advanced' PACS. Eight different flight conditions, representing the entire flight envelope, were evaluated with emphasis on the cruise flight conditions. These studies were made utilizing the Langley Visual/Motion Simulator (VMS) which has six degrees of freedom. The simulation tests indicated that (1) the flying qualities of the baseline aircraft (PACS off) for the cruise and other high-speed flight conditions were unacceptable at center-of-gravity positions aft of the neutral static stability point; (2) within the linear static stability flight envelope, the near-term PACS provided acceptable flying qualities for static stabilty margins to -3 percent; and (3) with the advanced PACS operative, the flying qualities were demonstrated to be good (satisfactory to very acceptable) for static stabilty margins to -20 percent.

  5. The yeast dynein Dyn2-Pac11 complex is a dynein dimerization/processivity factor: structural and single-molecule characterization

    PubMed Central

    Rao, Lu; Romes, Erin M.; Nicholas, Matthew P.; Brenner, Sibylle; Tripathy, Ashutosh; Gennerich, Arne; Slep, Kevin C.

    2013-01-01

    Cytoplasmic dynein is the major microtubule minus end–directed motor. Although studies have probed the mechanism of the C-terminal motor domain, if and how dynein's N-terminal tail and the accessory chains it binds regulate motor activity remain to be determined. Here, we investigate the structure and function of the Saccharomyces cerevisiae dynein light (Dyn2) and intermediate (Pac11) chains in dynein heavy chain (Dyn1) movement. We present the crystal structure of a Dyn2-Pac11 complex, showing Dyn2-mediated Pac11 dimerization. To determine the molecular effects of Dyn2 and Pac11 on Dyn1 function, we generated dyn2Δ and dyn2Δpac11Δ strains and analyzed Dyn1 single-molecule motor activity. We find that the Dyn2-Pac11 complex promotes Dyn1 homodimerization and potentiates processivity. The absence of Dyn2 and Pac11 yields motors with decreased velocity, dramatically reduced processivity, increased monomerization, aggregation, and immobility as determined by single-molecule measurements. Deleting dyn2 significantly reduces Pac11-Dyn1 complex formation, yielding Dyn1 motors with activity similar to Dyn1 from the dyn2Δpac11Δ strain. Of interest, motor phenotypes resulting from Dyn2-Pac11 complex depletion bear similarity to a point mutation in the mammalian dynein N-terminal tail (Loa), highlighting this region as a conserved, regulatory motor element. PMID:23761070

  6. The yeast dynein Dyn2-Pac11 complex is a dynein dimerization/processivity factor: structural and single-molecule characterization.

    PubMed

    Rao, Lu; Romes, Erin M; Nicholas, Matthew P; Brenner, Sibylle; Tripathy, Ashutosh; Gennerich, Arne; Slep, Kevin C

    2013-08-01

    Cytoplasmic dynein is the major microtubule minus end-directed motor. Although studies have probed the mechanism of the C-terminal motor domain, if and how dynein's N-terminal tail and the accessory chains it binds regulate motor activity remain to be determined. Here, we investigate the structure and function of the Saccharomyces cerevisiae dynein light (Dyn2) and intermediate (Pac11) chains in dynein heavy chain (Dyn1) movement. We present the crystal structure of a Dyn2-Pac11 complex, showing Dyn2-mediated Pac11 dimerization. To determine the molecular effects of Dyn2 and Pac11 on Dyn1 function, we generated dyn2Δ and dyn2Δpac11Δ strains and analyzed Dyn1 single-molecule motor activity. We find that the Dyn2-Pac11 complex promotes Dyn1 homodimerization and potentiates processivity. The absence of Dyn2 and Pac11 yields motors with decreased velocity, dramatically reduced processivity, increased monomerization, aggregation, and immobility as determined by single-molecule measurements. Deleting dyn2 significantly reduces Pac11-Dyn1 complex formation, yielding Dyn1 motors with activity similar to Dyn1 from the dyn2Δpac11Δ strain. Of interest, motor phenotypes resulting from Dyn2-Pac11 complex depletion bear similarity to a point mutation in the mammalian dynein N-terminal tail (Loa), highlighting this region as a conserved, regulatory motor element.

  7. Defining the Protected Antipode Circle (PAC) on the Farside of the Moon

    NASA Astrophysics Data System (ADS)

    Maccone, Claudio

    The international scientific community, and especially the IAA (International Academy of As-tronautics) have long been discussing the need to keep the Farside of the Moon free of man-made RFI (radio frequency interference). In fact, the center of the Farside, specifically crater Daedalus, is ideal to set up a future radiotelescope (or phased array) to detect radio waves of all kinds that it is impossible to detect on Earth because of both the ever-growing RFI and of the intervening ionosphere. Nobody, however, seems to have established a precise border for the circular region around the antipode of the Earth (i.e. zero latitude and 180o longitude both East and West) that should be Protected from wild human exploitation when several nations will have reached the capability of easy travel to the Moon. In this paper we propose the cre-ation of PAC, the Protected Antipode Circle, centered around the antipode on the Farside and spanning an angle of 30o in longitude, in latitude and in all radial directions from the antipode. There are sound scientific reasons for this definition: 1) PAC is the most shielded area of the Farside, with an expected attenuation of man-made RFI of 100 dB or higher; 2) PAC is the only area of the Farside that will never be reached by the radiation emitted by future human space bases located at the L4 and L5 Lagrangian points of the Earth-Moon system; 3) PAC does not overlap with other areas of interest to human activity except for possibly a minor common area with the Aitken Basin, the southern depression supposed to have been created 3.8 billion years ago during the "big wham" between the Earth and the Moon. In view of these unique features, we propose PAC to be officially recognized by the United Nations as an Internationally Protected Area where no radio contamination by humans will possibly take place now and in the future for the benefit of all Humankind.

  8. Perturbations of vortex ring pairs

    NASA Astrophysics Data System (ADS)

    Gubser, Steven S.; Horn, Bart; Parikh, Sarthak

    2016-02-01

    We study pairs of coaxial vortex rings starting from the action for a classical bosonic string in a three-form background. We complete earlier work on the phase diagram of classical orbits by explicitly considering the case where the circulations of the two vortex rings are equal and opposite. We then go on to study perturbations, focusing on cases where the relevant four-dimensional transfer matrix splits into two-dimensional blocks. When the circulations of the rings have the same sign, instabilities are mostly limited to wavelengths smaller than a dynamically generated length scale at which single-ring instabilities occur. When the circulations have the opposite sign, larger wavelength instabilities can occur.

  9. Perturbative nature of color superconductivity

    SciTech Connect

    Brown, William E.; Liu, James T.; Ren, Hai-cang

    2000-06-01

    Color superconductivity is a possible phase of high density QCD. We present a systematic derivation of the transition temperature T{sub C} from the QCD Lagrangian through study of the di-quark proper vertex. With this approach, we confirm the dependence of T{sub C} on the coupling g, namely T{sub C}{approx}{mu}g{sup -5}e{sup -{kappa}}{sup /g}, previously obtained from the one-gluon exchange approximation in the superconducting phase. The diagrammatic approach we employ allows us to examine the perturbative expansion of the vertex and the propagators. We find an additional O(1) contribution to the prefactor of the exponential from the one-loop quark self energy and that the other one-loop radiative contributions and the two gluon exchange vertex contribution are subleading. (c) 2000 The American Physical Society.

  10. Robust control with structured perturbations

    NASA Technical Reports Server (NTRS)

    Keel, Leehyun

    1988-01-01

    Two important problems in the area of control systems design and analysis are discussed. The first is the robust stability using characteristic polynomial, which is treated first in characteristic polynomial coefficient space with respect to perturbations in the coefficients of the characteristic polynomial, and then for a control system containing perturbed parameters in the transfer function description of the plant. In coefficient space, a simple expression is first given for the l(sup 2) stability margin for both monic and non-monic cases. Following this, a method is extended to reveal much larger stability region. This result has been extended to the parameter space so that one can determine the stability margin, in terms of ranges of parameter variations, of the closed loop system when the nominal stabilizing controller is given. The stability margin can be enlarged by a choice of better stabilizing controller. The second problem describes the lower order stabilization problem, the motivation of the problem is as follows. Even though the wide range of stabilizing controller design methodologies is available in both the state space and transfer function domains, all of these methods produce unnecessarily high order controllers. In practice, the stabilization is only one of many requirements to be satisfied. Therefore, if the order of a stabilizing controller is excessively high, one can normally expect to have a even higher order controller on the completion of design such as inclusion of dynamic response requirements, etc. Therefore, it is reasonable to have a lowest possible order stabilizing controller first and then adjust the controller to meet additional requirements. The algorithm for designing a lower order stabilizing controller is given. The algorithm does not necessarily produce the minimum order controller; however, the algorithm is theoretically logical and some simulation results show that the algorithm works in general.

  11. The linear shrinkage and microhardness of packable composites polymerized by QTH or PAC unit.

    PubMed

    Park, Song-Ho; Noh, Byng-Duk; Cho, Yong-Sik; Kim, Su-Sun

    2006-01-01

    This study evaluated the effectiveness of a plasma arc curing (PAC) unit for packable resin composite curing. The amount and speed of polymerization shrinkage and the microhardness of packable composites were evaluated in order to compare the PAC unit's effectiveness with a quartz tungsten halogen (QTH) unit. Sure Fil (Dentsply Caulk), Pyramid (BISCO Inc) and Synergy Compact (Colténe/Whaledent) were used as the packable composites. In the case of curing with the PAC unit, the composites were light cured with Apollo 95E (DMD System Inc) for 1 second (Group 1), 2 seconds (Group 2), 3 seconds (Group 3), 6 seconds (Group 4) and 12 seconds (Group 5). For light curing with the QTH unit, the composites were light cured for 60 seconds using XL3000 (Group 6). The linear polymerization shrinkage of each composite was measured using a custom made linometer, and the data was stored in a computer every 0.5 to 0.55 seconds for a total of 60 seconds. For each composite, the amount of polymerization was compared using one-way ANOVA with Tukey at the 95% confidence level. In order to compare the speed of polymerization, the peak time (PT), showing the highest speed of polymerization and maximum speed of polymerization (Smax), were determined from the data and compared using one-way ANOVA with Tukey at the 95% confidence level for each material. Based on the statistical analysis among the PAC-cure groups (Groups 1 through 5), the group that was not statistically different from the QTH-cure group (Group 6) in the amount of linear polymerization shrinkage was determined for each material, and the corresponding curing time of the group was defined as the tentative minimum PAC-curing time (TMPT). For microhardness measurements, the samples were placed in a 2-mm thick Teflon plate. Twenty specimens, randomly divided into the PAC-cure group (Group 1) or the QTH-cure group (Group 2), were prepared for each material. In Group 1, each composite was light cured for TMPT with the PAC unit. In

  12. The linear shrinkage and microhardness of packable composites polymerized by QTH or PAC unit.

    PubMed

    Park, Song-Ho; Noh, Byng-Duk; Cho, Yong-Sik; Kim, Su-Sun

    2006-01-01

    This study evaluated the effectiveness of a plasma arc curing (PAC) unit for packable resin composite curing. The amount and speed of polymerization shrinkage and the microhardness of packable composites were evaluated in order to compare the PAC unit's effectiveness with a quartz tungsten halogen (QTH) unit. Sure Fil (Dentsply Caulk), Pyramid (BISCO Inc) and Synergy Compact (Colténe/Whaledent) were used as the packable composites. In the case of curing with the PAC unit, the composites were light cured with Apollo 95E (DMD System Inc) for 1 second (Group 1), 2 seconds (Group 2), 3 seconds (Group 3), 6 seconds (Group 4) and 12 seconds (Group 5). For light curing with the QTH unit, the composites were light cured for 60 seconds using XL3000 (Group 6). The linear polymerization shrinkage of each composite was measured using a custom made linometer, and the data was stored in a computer every 0.5 to 0.55 seconds for a total of 60 seconds. For each composite, the amount of polymerization was compared using one-way ANOVA with Tukey at the 95% confidence level. In order to compare the speed of polymerization, the peak time (PT), showing the highest speed of polymerization and maximum speed of polymerization (Smax), were determined from the data and compared using one-way ANOVA with Tukey at the 95% confidence level for each material. Based on the statistical analysis among the PAC-cure groups (Groups 1 through 5), the group that was not statistically different from the QTH-cure group (Group 6) in the amount of linear polymerization shrinkage was determined for each material, and the corresponding curing time of the group was defined as the tentative minimum PAC-curing time (TMPT). For microhardness measurements, the samples were placed in a 2-mm thick Teflon plate. Twenty specimens, randomly divided into the PAC-cure group (Group 1) or the QTH-cure group (Group 2), were prepared for each material. In Group 1, each composite was light cured for TMPT with the PAC unit. In

  13. Ultra-sensitive and super-resolving angular rotation measurement based on photon orbital angular momentum using parity measurement.

    PubMed

    Zhang, Zijing; Qiao, Tianyuan; Ma, Kun; Cen, Longzhu; Zhang, Jiandong; Wang, Feng; Zhao, Yuan

    2016-08-15

    Photon orbital angular momentum has led to many novel insights and applications in quantum measurement. Photon orbital angular momentum can increase the resolution and sensitivity of angular rotation measurement. However, quantum measurement strategy can further surpass this limit and improve the resolution of angular rotation measurement. This Letter proposes and demonstrates a parity measurement method in angular rotation measurement scheme for the first time. Parity measurement can make the resolution superior to the limit of the existing method. The sensitivity can be improved with higher orbital angular momentum photons. Moreover, this Letter gives a detailed discussion of the change of resolution and sensitivity in the presence of photon loss. PMID:27519107

  14. Ultra-sensitive and super-resolving angular rotation measurement based on photon orbital angular momentum using parity measurement.

    PubMed

    Zhang, Zijing; Qiao, Tianyuan; Ma, Kun; Cen, Longzhu; Zhang, Jiandong; Wang, Feng; Zhao, Yuan

    2016-08-15

    Photon orbital angular momentum has led to many novel insights and applications in quantum measurement. Photon orbital angular momentum can increase the resolution and sensitivity of angular rotation measurement. However, quantum measurement strategy can further surpass this limit and improve the resolution of angular rotation measurement. This Letter proposes and demonstrates a parity measurement method in angular rotation measurement scheme for the first time. Parity measurement can make the resolution superior to the limit of the existing method. The sensitivity can be improved with higher orbital angular momentum photons. Moreover, this Letter gives a detailed discussion of the change of resolution and sensitivity in the presence of photon loss.

  15. The effects of a lateral in-flight perturbation on lower extremity biomechanics during drop landings.

    PubMed

    Yom, Jae P; Simpson, Kathy J; Arnett, Scott W; Brown, Cathleen N

    2014-10-01

    One potential ACL injury situation is due to contact with another person or object during the flight phase, thereby causing the person to land improperly. Conversely, athletes often have flight-phase collisions but do land safely. Therefore, to better understand ACL injury causation and methods by which people typically land safely, the purpose of this study was to determine the effects of an in-flight perturbation on the lower extremity biomechanics displayed by females during typical drop landings. Seventeen collegiate female recreational athletes performed baseline landings, followed by either unexpected laterally-directed perturbation or sham (nonperturbation) drop landings. We compared baseline and perturbation trials using paired-samples t tests (P < .05) and 95% confidence intervals for lower-extremity joint kinematics and kinetics and GRF. The results demonstrated that perturbation landings compared with baseline landings exhibited more extended joint positions of the lower extremity at initial contact; and, during landing, greater magnitudes for knee abduction and hip adduction displacements; peak magnitudes of vertical and medial GRF; and maximum moments of ankle extensors, knee extensors, and adductor and hip adductors. We conclude that a lateral in-flight perturbation leads to abnormal GRF and angular motions and joint moments of the lower extremity.

  16. Finite orbital angular momentum states and Laguerre-Gaussian potential in two-temperature electron plasmas

    NASA Astrophysics Data System (ADS)

    Shahzad, K.; Ali, S.

    2014-09-01

    Electron-acoustic waves are studied with orbital angular momentum (OAM) in an unmagnetized collisionless uniform plasma, whose constituents are the Boltzmann hot electrons, inertial cold electrons and stationary ions. For this purpose, we employ the fluid equations to obtain a paraxial equation in terms of cold electron density perturbations, which admits both the Gaussian and Laguerre-Gaussian (LG) beam solutions. Furthermore, an approximate solution for the electrostatic potential problem is found, which also allows us to express the components of the electric field in terms of LG potential perturbations. Calculating the energy flux of the electron-acoustic waves, an OAM density for these waves is obtained. Numerically, it is found that the parameters, such as, azimuthal angle, radial and angular mode numbers, and the beam waist strongly modify the LG potential profiles associated with electron-acoustic waves. The present results should be helpful to study the trapping and transportation of plasma particles and energy as well as to understand the electron-acoustic mode excitations produced by the Raman backscattering of laser beams in a uniform plasma.

  17. Kato expansion in quantum canonical perturbation theory

    NASA Astrophysics Data System (ADS)

    Nikolaev, Andrey

    2016-06-01

    This work establishes a connection between canonical perturbation series in quantum mechanics and a Kato expansion for the resolvent of the Liouville superoperator. Our approach leads to an explicit expression for a generator of a block-diagonalizing Dyson's ordered exponential in arbitrary perturbation order. Unitary intertwining of perturbed and unperturbed averaging superprojectors allows for a description of ambiguities in the generator and block-diagonalized Hamiltonian. We compare the efficiency of the corresponding computational algorithm with the efficiencies of the Van Vleck and Magnus methods for high perturbative orders.

  18. On adiabatic perturbations in the ekpyrotic scenario

    SciTech Connect

    Linde, A.; Mukhanov, V.; Vikman, A. E-mail: Viatcheslav.Mukhanov@physik.uni-muenchen.de

    2010-02-01

    In a recent paper, Khoury and Steinhardt proposed a way to generate adiabatic cosmological perturbations with a nearly flat spectrum in a contracting Universe. To produce these perturbations they used a regime in which the equation of state exponentially rapidly changed during a short time interval. Leaving aside the singularity problem and the difficult question about the possibility to transmit these perturbations from a contracting Universe to the expanding phase, we will show that the methods used in Khoury are inapplicable for the description of the cosmological evolution and of the process of generation of perturbations in this scenario.

  19. Quantum entanglement of high angular momenta.

    PubMed

    Fickler, Robert; Lapkiewicz, Radek; Plick, William N; Krenn, Mario; Schaeff, Christoph; Ramelow, Sven; Zeilinger, Anton

    2012-11-01

    Single photons with helical phase structures may carry a quantized amount of orbital angular momentum (OAM), and their entanglement is important for quantum information science and fundamental tests of quantum theory. Because there is no theoretical upper limit on how many quanta of OAM a single photon can carry, it is possible to create entanglement between two particles with an arbitrarily high difference in quantum number. By transferring polarization entanglement to OAM with an interferometric scheme, we generate and verify entanglement between two photons differing by 600 in quantum number. The only restrictive factors toward higher numbers are current technical limitations. We also experimentally demonstrate that the entanglement of very high OAM can improve the sensitivity of angular resolution in remote sensing.

  20. Performance criteria for dosimeter angular response

    SciTech Connect

    Roberson, P.L.; Fox, R. A.; Cummings, F. M.; McDonald, J. C.; Jones, K.L.

    1988-06-01

    This report provides criteria for evaluating the response of personnel dosimeters to radiation at nonperpendicular incidence. The US Department of Energy Laboratory Accreditation Program (DOELAP) ensures that dosimetry systems at DOE facilities meet acceptable standards for precision and accuracy. In the past, these standards were limited to tests for system variability, energy dependence, and level of detection. The proposed criteria will broaden the scope of DOELAP to include the angular response of personnel dosimeters. Because occupational exposures in the workplace are rarely due to radiation from only one direction, dosimeters must accurately assign individual dose equivalent from irradiation at any forward angle of incidence. Including an angular response criterion in DOELAP would improve the quality of personnel monitoring provided that the criterion is developed from appropriate dose quantities. This report provides guidance for assigning individual dose equivalents for radiation fields at nonperpendicular incidence to the dosimeter. 21 refs., 10 figs., 10 tabs.