WorldWideScience

Sample records for direct one-phonon spin-lattice

  1. Spin lattices of walking droplets

    Science.gov (United States)

    Saenz, Pedro; Pucci, Giuseppe; Goujon, Alexis; Dunkel, Jorn; Bush, John

    2017-11-01

    We present the results of an experimental investigation of the spontaneous emergence of collective behavior in spin lattice of droplets walking on a vibrating fluid bath. The bottom topography consists of relatively deep circular wells that encourage the walking droplets to follow circular trajectories centered at the lattice sites, in one direction or the other. Wave-mediated interactions between neighboring drops are enabled through a thin fluid layer between the wells. The sense of rotation of the walking droplets may thus become globally coupled. When the coupling is sufficiently strong, interactions with neighboring droplets may result in switches in spin that lead to preferred global arrangements, including correlated (all drops rotating in the same direction) or anti-correlated (neighboring drops rotating in opposite directions) states. Analogies with ferromagnetism and anti-ferromagnetism are drawn. Different spatial arrangements are presented in 1D and 2D lattices to illustrate the effects of topological frustration. This work was supported by the US National Science Foundation through Grants CMMI-1333242 and DMS-1614043.

  2. Spin-lattice relaxation of individual solid-state spins

    Science.gov (United States)

    Norambuena, A.; Muñoz, E.; Dinani, H. T.; Jarmola, A.; Maletinsky, P.; Budker, D.; Maze, J. R.

    2018-03-01

    Understanding the effect of vibrations on the relaxation process of individual spins is crucial for implementing nanosystems for quantum information and quantum metrology applications. In this work, we present a theoretical microscopic model to describe the spin-lattice relaxation of individual electronic spins associated to negatively charged nitrogen-vacancy centers in diamond, although our results can be extended to other spin-boson systems. Starting from a general spin-lattice interaction Hamiltonian, we provide a detailed description and solution of the quantum master equation of an electronic spin-one system coupled to a phononic bath in thermal equilibrium. Special attention is given to the dynamics of one-phonon processes below 1 K where our results agree with recent experimental findings and analytically describe the temperature and magnetic-field scaling. At higher temperatures, linear and second-order terms in the interaction Hamiltonian are considered and the temperature scaling is discussed for acoustic and quasilocalized phonons when appropriate. Our results, in addition to confirming a T5 temperature dependence of the longitudinal relaxation rate at higher temperatures, in agreement with experimental observations, provide a theoretical background for modeling the spin-lattice relaxation at a wide range of temperatures where different temperature scalings might be expected.

  3. Parallel computer calculation of quantum spin lattices

    International Nuclear Information System (INIS)

    Lamarcq, J.

    1998-01-01

    Numerical simulation allows the theorists to convince themselves about the validity of the models they use. Particularly by simulating the spin lattices one can judge about the validity of a conjecture. Simulating a system defined by a large number of degrees of freedom requires highly sophisticated machines. This study deals with modelling the magnetic interactions between the ions of a crystal. Many exact results have been found for spin 1/2 systems but not for systems of other spins for which many simulation have been carried out. The interest for simulations has been renewed by the Haldane's conjecture stipulating the existence of a energy gap between the ground state and the first excited states of a spin 1 lattice. The existence of this gap has been experimentally demonstrated. This report contains the following four chapters: 1. Spin systems; 2. Calculation of eigenvalues; 3. Programming; 4. Parallel calculation

  4. The water proton spin-lattice relaxation times in virus-infected cells

    International Nuclear Information System (INIS)

    Valensin, G.; Gaggelli, E.; Tiezzi, E.; Valensin, P.E.; Bianchi Bandinelli, M.L.

    1979-01-01

    The water proton spin-lattice relaxation times in HEp-2 cell cultures were determined immediately after 1 h of polio-virus adsorption. The shortening of the water T 1 was closely related to the multiplicity of infection, allowing direct inspections of the virus-cell interaction since the first steps of the infectious cycle. Virus-induced structural and conformational changes of cell constituents were suggested to be detectable by NMR investigation of cell water. (Auth.)

  5. Measurements of spin-lattice relaxation time in mixed alkali halide crystals

    International Nuclear Information System (INIS)

    Tannus, A.

    1983-01-01

    Using magneto-optic techniques the ground state spin-lattice relaxation times (T1) of 'F' centers in mixed Alkali Halide cristals (KCl-KBr), was studied. A computer assisted system to optically measure short relaxation times (approx. = 1mS), was described. The technique is based on the measurement of the Magnetic Circular Dicroism (MCD) presented by F centers. The T1 magnetic field dependency at 2 K (up to 65 KGauss), was obtained as well as the MCD spectra for different relative concentration at the mixed matrices. The theory developed by Panepucci and Mollenauer for F centers spin-lattice relaxation in pure matrices was modified to explain the behaviour of T1 in mixed cristals. The Direct Process results (T approx. = 2.0 K) compared against that theory shows that the main relaxation mecanism, up to 25 KGauss, continues to be phonon modulation of the hiperfine iteraction between F electrons and surrounding nuclei. (Author) [pt

  6. One-phonon scattering of ultra cold neutrons in copper

    International Nuclear Information System (INIS)

    Holas, A.

    1977-01-01

    Experiments with ultra cold neutrons (UCN) showed that their lifetime in a closed vessel is much smaller than expected. In order to explain this phenomenon, many different mechanisms leading to heating of UCN were proposed, among other things one-phonon coherent inelastic scattering (with phonon absorption). This paper shows quantitatively the contribution of this process to the total heating of UCN

  7. Nuclear spin-lattice relaxation in nitroxide spin-label EPR.

    Science.gov (United States)

    Marsh, Derek

    2016-11-01

    Nuclear relaxation is a sensitive monitor of rotational dynamics in spin-label EPR. It also contributes competing saturation transfer pathways in T 1 -exchange spectroscopy, and the determination of paramagnetic relaxation enhancement in site-directed spin labelling. A survey shows that the definition of nitrogen nuclear relaxation rate W n commonly used in the CW-EPR literature for 14 N-nitroxyl spin labels is inconsistent with that currently adopted in time-resolved EPR measurements of saturation recovery. Redefinition of the normalised 14 N spin-lattice relaxation rate, b=W n /(2W e ), preserves the expressions used for CW-EPR, whilst rendering them consistent with expressions for saturation recovery rates in pulsed EPR. Furthermore, values routinely quoted for nuclear relaxation times that are deduced from EPR spectral diffusion rates in 14 N-nitroxyl spin labels do not accord with conventional analysis of spin-lattice relaxation in this three-level system. Expressions for CW-saturation EPR with the revised definitions are summarised. Data on nitrogen nuclear spin-lattice relaxation times are compiled according to the three-level scheme for 14 N-relaxation: T 1 n =1/W n . Results are compared and contrasted with those for the two-level 15 N-nitroxide system. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Nuclear spin-lattice relaxation in carbon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Panich, A.M., E-mail: pan@bgu.ac.i [Department of Physics, Ben-Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel); Sergeev, N.A. [Institute of Physics, University of Szczecin, 70-451 Szczecin (Poland)

    2010-04-15

    Interpretation of nuclear spin-lattice relaxation data in the carbon nanostructures is usually based on the analysis of fluctuations of dipole-dipole interactions of nuclear spins and anisotropic electron-nuclear interactions responsible for chemical shielding, which are caused by molecular dynamics. However, many nanocarbon systems such as fullerene and nanotube derivatives, nanodiamonds and carbon onions reveal noticeable amount of paramagnetic defects with unpaired electrons originating from dangling bonds. The interaction between nuclear and electron spins strongly influences the nuclear spin-lattice relaxation, but usually is not taken into account, thus the relaxation data are not correctly interpreted. Here we report on the temperature dependent NMR spectra and spin-lattice relaxation measurements of intercalated fullerenes C{sub 60}(MF{sub 6}){sub 2} (M=As and Sb), where nuclear relaxation is caused by both molecular rotation and interaction between nuclei and unpaired electron spins. We present a detailed theoretical analysis of the spin-lattice relaxation data taking into account both these contributions. Good agreement between the experimental data and calculations is obtained. The developed approach would be useful in interpreting the NMR relaxation data in different nanostructures and their intercalation compounds.

  9. Spin-Lattice Coupling and Superconductivity in Fe Pnictides

    Directory of Open Access Journals (Sweden)

    T. Egami

    2010-01-01

    Full Text Available We consider strong spin-lattice and spin-phonon coupling in iron pnictides and discuss its implications on superconductivity. Strong magneto-volume effect in iron compounds has long been known as the Invar effect. Fe pnictides also exhibit this effect, reflected in particular on the dependence of the magnetic moment on the atomic volume of Fe defined by the positions of the nearest neighbor atoms. Through the phenomenological Landau theory, developed on the basis of the calculations by the density functional theory (DFT and the experimental results, we quantify the strength of the spin-lattice interaction as it relates to the Stoner criterion for the onset of magnetism. We suggest that the coupling between electrons and phonons through the spin channel may be sufficiently strong to be an important part of the superconductivity mechanism in Fe pnictides.

  10. Analytic treatment of nuclear spin-lattice relaxation for diffusion in a cone model

    Science.gov (United States)

    Sitnitsky, A. E.

    2011-12-01

    We consider nuclear spin-lattice relaxation rate resulted from a diffusion equation for rotational wobbling in a cone. We show that the widespread point of view that there are no analytical expressions for correlation functions for wobbling in a cone model is invalid and prove that nuclear spin-lattice relaxation in this model is exactly tractable and amenable to full analytical description. The mechanism of relaxation is assumed to be due to dipole-dipole interaction of nuclear spins and is treated within the framework of the standard Bloemberger, Purcell, Pound-Solomon scheme. We consider the general case of arbitrary orientation of the cone axis relative the magnetic field. The BPP-Solomon scheme is shown to remain valid for systems with the distribution of the cone axes depending only on the tilt relative the magnetic field but otherwise being isotropic. We consider the case of random isotropic orientation of cone axes relative the magnetic field taking place in powders. Also we consider the cases of their predominant orientation along or opposite the magnetic field and that of their predominant orientation transverse to the magnetic field which may be relevant for, e.g., liquid crystals. Besides we treat in details the model case of the cone axis directed along the magnetic field. The latter provides direct comparison of the limiting case of our formulas with the textbook formulas for free isotropic rotational diffusion. The dependence of the spin-lattice relaxation rate on the cone half-width yields results similar to those predicted by the model-free approach.

  11. Spin-lattice relaxation in phosphorescent triplet state molecules

    International Nuclear Information System (INIS)

    Verbeek, P.J.F.

    1979-01-01

    The present thesis contains the results of a study of spin-lattice relaxation (SLR) in the photo-excited triplet state of aromatic molecules, dissolved in a molecular host crystal. It appears that SLR in phosphorescent triplet state molecules often is related to the presence of so-called (pseudo) localized phonons in the molecular mixed crystals. These local phonons can be thought to correspond with vibrations (librations) of the guest molecule in the force field of the surrounding host molecules. Since the intermolecular forces are relatively weak, the frequencies corresponding with these vibrations are relatively low and usually are of the order of 10-30 cm -1 . (Auth.)

  12. Localized-magnon states in strongly frustrated quantum spin lattices

    International Nuclear Information System (INIS)

    Richter, J.

    2005-01-01

    Recent developments concerning localized-magnon eigenstates in strongly frustrated spin lattices and their effect on the low-temperature physics of these systems in high magnetic fields are reviewed. After illustrating the construction and the properties of localized-magnon states we describe the plateau and the jump in the magnetization process caused by these states. Considering appropriate lattice deformations fitting to the localized magnons we discuss a spin-Peierls instability in high magnetic fields related to these states. Last but not least we consider the degeneracy of the localized-magnon eigenstates and the related thermodynamics in high magnetic fields. In particular, we discuss the low-temperature maximum in the isothermal entropy versus field curve and the resulting enhanced magnetocaloric effect, which allows efficient magnetic cooling from quite large temperatures down to very low ones

  13. Nuclear spin-lattice relaxation in nitroxide spin-label EPR

    DEFF Research Database (Denmark)

    Marsh, Derek

    2016-01-01

    that the definition of nitrogen nuclear relaxation rate Wn commonly used in the CW-EPR literature for 14N-nitroxyl spin labels is inconsistent with that currently adopted in time-resolved EPR measurements of saturation recovery. Redefinition of the normalised 14N spin-lattice relaxation rate, b = Wn/(2We), preserves...... of spin-lattice relaxation in this three-level system. Expressions for CW-saturation EPR with the revised definitions are summarised. Data on nitrogen nuclear spin-lattice relaxation times are compiled according to the three-level scheme for 14N-relaxation: T1 n = 1/Wn. Results are compared and contrasted...

  14. Phase separation, clustering, and fractal characteristics in glass: A magic-angle-spinning NMR spin-lattice relaxation study

    Science.gov (United States)

    Sen, S.; Stebbins, J. F.

    1994-07-01

    A comparative study of the 29Si spin-lattice relaxation behavior (induced by trace amounts of paramagnetic dopants in the glass) in phase-separated Li2Si4O9 and monophasic Li2Si2O5 and Na2Si2O5 glasses has been made in order to understand the nature of clustering and the resulting intermediate-range ordering. Optically clear tetrasilicate and disilicate glasses were prepared with 500 to 2000 ppm of Gd2O3, a paramagnetic dopant. The constituent structural units (Q3 and Q4 species) in all tetrasilicate glasses show strong differential relaxation following a power-law behavior. This is due to preferential partitioning of Gd3+ into the lower silica (Q3-rich) regions of these glasses, indicating the presence of Q species clusters too small to produce optical opalescence (a few nm to perhaps tens of nm). Preliminary results on 6Li spin-lattice relaxation in these glasses support this hypothesis. Differential relaxation becomes more pronounced on annealing due to growth of such clusters. No such differential relaxation was observed in the monophase disilicate glasses. For spin-lattice relaxation induced by direct dipolar coupling to paramagnetic ions, the recovery of magnetization is proportional to time as M(t)~tα where α is a function of the dimensionality D of mass distribution of the constituent Q species around the Gd3+ paramagnetic centers in the glass. For tetrasilicate glasses D~=2.62+/-0.22 and the system behaves as a mass fractal up to a length scale of 2 to 3 nm. D is thus equal to, within error, the theoretical value of 2.6 for an infinite percolation cluster of one type of Q species in another. For disilicate glasses, D~=3.06+/-0.18 which indicates a three-dimensional (and thus nonfractal) mass distribution of the constituent Q species over the same length scale.

  15. Evaluation of PHB/Clay nanocomposite by spin-lattice relaxation time

    Directory of Open Access Journals (Sweden)

    Mariana Bruno

    2008-12-01

    Full Text Available Poly(3-hydroxybutyrate (PHB based on nanocomposites containing different amounts of a commercial organically modified clay (viscogel B7 were prepared employing solution intercalation method. Three solvents, such as: CHCl3, dimethylchloride (DMC and tetrahydrofuran (THF were used. The relationship among the processing conditions; molecular structure and intermolecular interaction, between both nanocomposite components, were investigated using a nuclear magnetic resonance (NMR, as a part of characterization methodology, which has been used by Tavares et al. It involves the hydrogen spin-lattice relaxation time, T1H, by solid state nuclear magnetic resonance, employing low field NMR. X ray diffraction was also employed because it is a conventional technique, generally used to obtain the first information on nanocomposite formation. Changes in PHB crystallinity were observed after the organophilic nanoclay had been incorporated in the polymer matrix. These changes, in the microstructure, were detected by the variation of hydrogen nuclear relaxation time values and by X ray, which showed an increase in the clay interlamelar space due to the intercalation of the polymer in the clay between lamellae. It was also observed, for both techniques, that the solvents affect directly the organization of the crystalline region, promoting a better intercalation, considering that they behave like a plasticizer.

  16. Efficiency of free-energy calculations of spin lattices by spectral quantum algorithms

    International Nuclear Information System (INIS)

    Master, Cyrus P.; Yamaguchi, Fumiko; Yamamoto, Yoshihisa

    2003-01-01

    Ensemble quantum algorithms are well suited to calculate estimates of the energy spectra for spin-lattice systems. Based on the phase estimation algorithm, these algorithms efficiently estimate discrete Fourier coefficients of the density of states. Their efficiency in calculating the free energy per spin of general spin lattices to bounded error is examined. We find that the number of Fourier components required to bound the error in the free energy due to the broadening of the density of states scales polynomially with the number of spins in the lattice. However, the precision with which the Fourier components must be calculated is found to be an exponential function of the system size

  17. One-phonon states in deformed nuclei for isoscalar and isovector interactions

    International Nuclear Information System (INIS)

    Malov, L.A.; Nesterenko, V.O.; Solov'ev, V.G.

    1977-01-01

    Extension of the formulas describing the one-phonon states of compound even-even deformed nuclei to the case when the isoscalar and isovector multipole-multipole forces are taken into account, is given. The formalism presented makes it possible to obtain an unified description of the low-lying states and gigantic multipole resonances. Procedure is developed which makes it possible to write down the reduced probability and energetically weighted sum rule in the form of force functions averaged over certain interval of energies. The procedure simplifies the calculations significantly and makes it possible to avoid solving the secular equation for energies of one-phonon states

  18. Spin manipulation and spin-lattice interaction in magnetic colloidal quantum dots

    OpenAIRE

    Moro, F.; Turyanska, L.; Granwehr, J.; Patane, A.

    2014-01-01

    We report on the spin-lattice interaction and coherent manipulation of electron spins in Mn-doped colloidal PbS quantum dots (QDs) by electron spin resonance. We show that the phase memory time,TM, is limited by Mn-Mn dipolar interactions, hyperfine interactions of the protons (H1) on the QD capping ligands with Mn ions in their proximity (

  19. Size dependence of 13C nuclear spin-lattice relaxation in micro- and nanodiamonds

    Science.gov (United States)

    Panich, A. M.; Sergeev, N. A.; Shames, A. I.; Osipov, V. Yu; Boudou, J.-P.; Goren, S. D.

    2015-02-01

    Size dependence of physical properties of nanodiamond particles is of crucial importance for various applications in which defect density and location as well as relaxation processes play a significant role. In this work, the impact of defects induced by milling of micron-sized synthetic diamonds was studied by magnetic resonance techniques as a function of the particle size. EPR and 13C NMR studies of highly purified commercial synthetic micro- and nanodiamonds were done for various fractions separated by sizes. Noticeable acceleration of 13C nuclear spin-lattice relaxation with decreasing particle size was found. We showed that this effect is caused by the contribution to relaxation coming from the surface paramagnetic centers induced by sample milling. The developed theory of the spin-lattice relaxation for such a case shows good compliance with the experiment.

  20. Concentration dependence of fluorine impurity spin-lattice relaxation rate in bone mineral

    International Nuclear Information System (INIS)

    Code, R.F.; Armstrong, R.L.; Cheng, P.-T.

    1992-01-01

    The concentration dependence of the fluoride ion spin-lattice relaxation rate has been observed by nuclear magnetic resonance experiments on samples of defatted and dried bone. The 19 F spin-lattice relaxation rates increased linearly with bone fluoride concentration. Different results were obtained from trabecular than from cortical bone. For the same macroscopic fluoride content per gram of bone calcium, relaxation rate is significantly faster in cortical bone. Relaxation rates in cortical bone samples prepared from rats and dogs were apparently controlled by the same species-independent processes. For samples from beagle dogs, bulk fluoride concentrations measured by neutron activation analysis were 3.1±0.3 times greater in trabecular bone than in corresponding cortical bone. The beagle spin-lattice relaxation data suggest that microscopic fluoride concentrations in bone mineral were 1.8±0.4 times greater in trabecular bone than in cortical bone. It is concluded that accumulation of fluoride impurities in bone mineral is non-uniform. (author)

  1. One phonon resonant Raman scattering in semiconductor quantum wires: Magnetic field effect

    Energy Technology Data Exchange (ETDEWEB)

    Betancourt-Riera, Re., E-mail: rbriera@posgrado.cifus.uson.mx [Instituto Tecnologico de Hermosillo, Avenida Tecnologico S/N, Colonia Sahuaro, C.P. 83170, Hermosillo, Sonor, (Mexico); Departamento de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, C.P. 83190, Hermosillo, Sonora (Mexico); Betancourt-Riera, Ri. [Instituto Tecnologico de Hermosillo, Avenida Tecnologico S/N, Colonia Sahuaro, C.P. 83170, Hermosillo, Sonora (Mexico); Nieto Jalil, J.M. [Tecnologico de Monterrey-Campus Sonora Norte, Bulevar Enrique Mazon Lopez No. 965, C.P. 83000, Hermosillo, Sonora (Mexico); Riera, R. [Departamento de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, C.P. 83190, Hermosillo, Sonora (Mexico)

    2013-02-01

    We have developed a theory of one phonon resonant Raman scattering in a semiconductor quantum wire of cylindrical geometry in the presence of an external magnetic field distribution, parallel to the cylinder axis. The effect of the magnetic field in the electron and hole states, and in the Raman scattering efficiency, is determinate. We consider the electron-phonon interaction using a Froehlich-type Hamiltonian, deduced for the case of complete confinement phonon modes by Comas and his collaborators. We also assume T=0 K, a single parabolic conduction and valence bands. The spectra are discussed for different magnetic field values and the selection rules for the processes are also studied.

  2. Measurement of sample temperatures under magic-angle spinning from the chemical shift and spin-lattice relaxation rate of 79Br in KBr powder.

    Science.gov (United States)

    Thurber, Kent R; Tycko, Robert

    2009-01-01

    Accurate determination of sample temperatures in solid state nuclear magnetic resonance (NMR) with magic-angle spinning (MAS) can be problematic, particularly because frictional heating and heating by radio-frequency irradiation can make the internal sample temperature significantly different from the temperature outside the MAS rotor. This paper demonstrates the use of (79)Br chemical shifts and spin-lattice relaxation rates in KBr powder as temperature-dependent parameters for the determination of internal sample temperatures. Advantages of this method include high signal-to-noise, proximity of the (79)Br NMR frequency to that of (13)C, applicability from 20 K to 320 K or higher, and simultaneity with adjustment of the MAS axis direction. We show that spin-lattice relaxation in KBr is driven by a quadrupolar mechanism. We demonstrate a simple approach to including KBr powder in hydrated samples, such as biological membrane samples, hydrated amyloid fibrils, and hydrated microcrystalline proteins, that allows direct assessment of the effects of frictional and radio-frequency heating under experimentally relevant conditions.

  3. Theory of spin-lattice relaxation of diffusing light nuclei in glasses

    International Nuclear Information System (INIS)

    Schirmer, A.; Schirmacher, W.

    1988-01-01

    NMR data of diffusion-induced spin-lattice relaxation in glasses cannot generally be interpreted in the framework of the classical theory of Bloembergen, Purcell and Pound (BPP). Since it is based on exponential density relaxation, generally bnot found in glasses, the BPP formula must be generalized. Here a combination of standard relaxation theory with a hopping model for diffusion in glasses is present. It is shown that the observed anomaties in the NMR data can be explained as a result of anomalous diffusion. 25 refs.; 1 figure

  4. Spin-lattice relaxation times and knight shift in InSb and InAs

    International Nuclear Information System (INIS)

    Braun, P.; Grande, S.

    1976-01-01

    For a dominant contact interaction between nuclei and conduction electrons the relaxation rate is deduced. The extreme cases of degenerate and non-degenerate semiconductors are separately discussed. At strong degeneracy the product of the Knight shift and relaxation time gives the Korringa relation for metals. Measurements of the NMR spin-lattice relaxation times of 115 InSb and 115 InAs were made between 4.2 and 300 K for strongly degenerated samples. The different relaxation mechanisms are discussed and the experimental and theoretical results are compared. (author)

  5. Magnon and phonon dispersion, lifetime, and thermal conductivity of iron from spin-lattice dynamics simulations

    Science.gov (United States)

    Wu, Xufei; Liu, Zeyu; Luo, Tengfei

    2018-02-01

    In recent years, the fundamental physics of spin-lattice (e.g., magnon-phonon) interaction has attracted significant experimental and theoretical interests given its potential paradigm-shifting impacts in areas like spin-thermoelectrics, spin-caloritronics, and spintronics. Modelling studies of the transport of magnons and phonons in magnetic crystals are very rare. In this paper, we use spin-lattice dynamics (SLD) simulations to model ferromagnetic crystalline iron, where the spin and lattice systems are coupled through the atomic position-dependent exchange function, and thus the interaction between magnons and phonons is naturally considered. We then present a method combining SLD simulations with spectral energy analysis to calculate the magnon and phonon harmonic (e.g., dispersion, specific heat, and group velocity) and anharmonic (e.g., scattering rate) properties, based on which their thermal conductivity values are calculated. This work represents an example of using SLD simulations to understand the transport properties involving coupled magnon and phonon dynamics.

  6. Microwave Amplitude Modulation Technique to Measure Spin-Lattice (T 1) and Spin-Spin (T 2) Relaxation Times

    Science.gov (United States)

    Misra, Sushil K.

    The measurement of very short spin-lattice, or longitudinal, relaxation (SLR) times (i.e., 10-10 Misra, 1998), and polymer resins doped with rare-earth ions (Pescia et al., 1999a; Pescia et al. 1999b). The ability to measure such fast SLR data on amorphous Si and copper-chromium-tin spinel led to an understanding of the role of exchange interaction in affecting spin-lattice relaxation, while the data on polymer resins doped with rare-earth ions provided evidence of spin-fracton relaxation (Pescia et al., 1999a, b). But such fast SLR times are not measurable by the most commonly used techniques of saturation- and inversion-recovery (Poole, 1982; Alger, 1968), which only measure spin-lattice relaxation times longer than 10-6 s. A summary of relevant experimental data is presented in Table 1.

  7. Electron spin-lattice relaxation mechanisms of radiation produced trapped electrons and hydrogen atoms in aqueous and organic glassy matrices. Modulation of electron nuclear dipolar interaction by tunnelling modes in a glassy matrix. [. gamma. rays

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, M K; Kevan, L [Wayne State Univ., Detroit, Mich. (USA). Dept. of Chemistry

    1977-01-01

    The spin lattice relaxation of trapped electrons in aqueous and organic glasses and trapped hydrogen atoms in phosphoric acid glass has been directly studied as a function of temperature by the saturation recovery method. Below 50 to 100 K, the major spin lattice relaxation mechanism involves modulation of the electron nuclear dipolar (END) interaction with nuclei in the radical's environment by tunnelling of those nuclei between two or more positions. This relaxation mechanism occurs with high efficiency and has a characteristic linear temperature dependence. The tunnelling nuclei around trapped electrons do not seem to involve the nearest neighbor nuclei which are oriented by the electron in the process of solvation. Instead the tunnelling nuclei typically appear to be next nearest neighbors to the trapped electron. The identities of the tunnelling nuclei have been deduced by isotopic substitution and are attributed to: Na in 10 mol dm/sup -3/ NaOH aqueous glass, ethyl protons in ethanol glass, methyl protons in methanol glass and methyl protons in MTHF glass. For trapped hydrogen atoms in phosphoric acid, the phosphorus nuclei appear to be the effective tunnelling nuclei. Below approximately 10 K the spin lattice relaxation is dominated by a temperature independent cross relaxation term for H atoms in phosphoric acid glass and for electrons in 10 mol dm/sup -3/ NaOH aqueous glass, but not for electrons in organic glasses. This is compared with recent electron-electron double resonance studies of cross relaxation in these glasses. The spin lattice relaxation of O/sup -/ formed in 10 mol dm/sup -3/ NaOH aqueous glass was also studied and found to be mainly dominated by a Raman process with an effective Debye temperature of about 100 K.

  8. Parallel computer calculation of quantum spin lattices; Calcul de chaines de spins quantiques sur ordinateur parallele

    Energy Technology Data Exchange (ETDEWEB)

    Lamarcq, J. [Service de Physique Theorique, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1998-07-10

    Numerical simulation allows the theorists to convince themselves about the validity of the models they use. Particularly by simulating the spin lattices one can judge about the validity of a conjecture. Simulating a system defined by a large number of degrees of freedom requires highly sophisticated machines. This study deals with modelling the magnetic interactions between the ions of a crystal. Many exact results have been found for spin 1/2 systems but not for systems of other spins for which many simulation have been carried out. The interest for simulations has been renewed by the Haldane`s conjecture stipulating the existence of a energy gap between the ground state and the first excited states of a spin 1 lattice. The existence of this gap has been experimentally demonstrated. This report contains the following four chapters: 1. Spin systems; 2. Calculation of eigenvalues; 3. Programming; 4. Parallel calculation 14 refs., 6 figs.

  9. Spin-lattice interactions studied by polarised and unpolarised inelastic scattering application to the invar problem

    Energy Technology Data Exchange (ETDEWEB)

    Brown, P J [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1996-11-01

    A semi-quantitative analysis is given of some of the ways in which spin-lattice interactions can modify the cross-sections observable in neutron scattering experiments. This analysis is applied to the scattering from the invar alloy Fe{sub 65}Ni{sub 35} using a model in which the magnetic moment is a function of the near neighbour separation. This model has been applied to clarify the results of inelastic scattering experiments carried out on Fe{sub 65}Ni{sub 35} using both polarised and unpolarised neutrons. The extra information obtainable using polarised neutrons as well as the difficulties and limitations of the technique for inelastic scattering are discussed. (author) 8 figs., 14 refs.

  10. Spin-lattice dynamics simulation of external field effect on magnetic order of ferromagnetic iron

    Directory of Open Access Journals (Sweden)

    C. P. Chui

    2014-03-01

    Full Text Available Modeling of field-induced magnetization in ferromagnetic materials has been an active topic in the last dozen years, yet a dynamic treatment of distance-dependent exchange integral has been lacking. In view of that, we employ spin-lattice dynamics (SLD simulations to study the external field effect on magnetic order of ferromagnetic iron. Our results show that an external field can increase the inflection point of the temperature. Also the model provides a better description of the effect of spin correlation in response to an external field than the mean-field theory. An external field has a more prominent effect on the long range magnetic order than on the short range counterpart. Furthermore, an external field allows the magnon dispersion curves and the uniform precession modes to exhibit magnetic order variation from their temperature dependence.

  11. Spin manipulation and spin-lattice interaction in magnetic colloidal quantum dots

    Science.gov (United States)

    Moro, Fabrizio; Turyanska, Lyudmila; Granwehr, Josef; Patanè, Amalia

    2014-11-01

    We report on the spin-lattice interaction and coherent manipulation of electron spins in Mn-doped colloidal PbS quantum dots (QDs) by electron spin resonance. We show that the phase memory time,TM , is limited by Mn-Mn dipolar interactions, hyperfine interactions of the protons (1H) on the QD capping ligands with Mn ions in their proximity (limit and at low temperature, we achieve a long phase memory time constant TM˜0.9 μ s , thus enabling the observation of Rabi oscillations. Our findings suggest routes to the rational design of magnetic colloidal QDs with phase memory times exceeding the current limits of relevance for the implementation of QDs as qubits in quantum information processing.

  12. Nonuniversal scaling of the magnetocaloric effect as an insight into spin-lattice interactions in manganites

    DEFF Research Database (Denmark)

    Smith, Anders; Nielsen, Kaspar Kirstein; Neves Bez, Henrique

    2016-01-01

    is not given uniquely by the critical exponents of the ferromagnetic-paramagnetic phase transition, i.e., the scaling is nonuniversal. A theoretical description based on the Bean-Rodbell model and taking into account compositional inhomogeneities is shown to be able to account for the observed field dependence....... In this way the determination of the nonuniversal field dependence of the magnetocaloric effect close to a phase transition can be used as a method to gain insight into the strength of the spin-lattice interactions of magnetic materials. The approach is shown also to be applicable to first-order transitions.......We measure the magnetocaloric effect of the manganite series La0.67Ca0.33-xSrxMnO3 by determining the isothermal entropy change upon magnetization, using variable-field calorimetry. The results demonstrate that the field dependence of the magnetocaloric effect close to the critical temperature...

  13. Nonlinear nano-scale localized breather modes in a discrete weak ferromagnetic spin lattice

    International Nuclear Information System (INIS)

    Kavitha, L.; Parasuraman, E.; Gopi, D.; Prabhu, A.; Vicencio, Rodrigo A.

    2016-01-01

    We investigate the propagation dynamics of highly localized discrete breather modes in a weak ferromagnetic spin lattice with on-site easy axis anisotropy due to crystal field effect. We derive the discrete nonlinear equation of motion by employing boson mappings and p-representation. We explore the onset of modulational instability both analytically in the framework of linear stability analysis and numerically by means of molecular dynamics (MD) simulations, and a perfect agreement was demonstrated. It is also explored that how the antisymmetric nature of the canted ferromagnetic lattice supports highly localized discrete breather (DBs) modes as shown in the stability/instability windows. The energy exchange between low amplitude discrete breathers favours the growth of higher amplitude DBs, resulting eventually in the formation of few long-lived high amplitude DBs. - Highlights: • The effects of DM and anisotropy interaction on the DB modes are studied. • The antisymmetric nature of the canted ferromagnetic medium supports the DB modes. • Dynamics of ferromagnetic chain is governed by boson mappings and p-representation.

  14. 31P spin-lattice relaxation time measurements in biological systems

    International Nuclear Information System (INIS)

    Suzuki, Eiji; Maeda, Munehiro; Kuki, Satoru; Tsukamoto, Kenji; Kawakami, Tsuyoshi; Seo, Yoshiteru; Murakami, Masataka; Watari, Hiroshi

    1989-01-01

    Spin-lattice relaxation time (T 1 ) of phosphorus compounds in the perfused heart, liver, kidney and erythrocytes of rats were measured by the DESPOT (Driven-equilibrium single-pulse observation of T 1 ) method at 8.45 T. This method is a rapid and accurate technique for the measurement of T 1 values. T 1 values of phosphomonoesters (PME), 2, 3-diphosphoglycerate (DPG), inorganic phosphate (Pi), phosphodiesters (PDE), phosphocreatine (PCr) and three phosphates of ATP were ranged from 0.15±0.02 sec (β-ATP in the liver) to 8.5±1.6 sec (PDE in the kidney). T 1 value of β-ATP in the liver was 1/4-1/5 of those in the mandibular gland, heart, erythrocytes and kidney. T 1 values obtained from biological materials are useful for selecting the optimal pulse repetition times and pulse angles to maximize the signal-to-noise ratio of 13 P spectra, and for correcting distortions of signal intensities in the spectra. (author)

  15. Dynamic Spin-Lattice Coupling and Nematic Fluctuations in NaFeAs

    Directory of Open Access Journals (Sweden)

    Yu Li

    2018-06-01

    Full Text Available We use inelastic neutron scattering to study acoustic phonons and spin excitations in single crystals of NaFeAs, a parent compound of iron-pnictide superconductors. NaFeAs exhibits a tetragonal-to-orthorhombic structural transition at T_{s}≈58  K and a collinear antiferromagnetic order at T_{N}≈45  K. While longitudinal and out-of-plane transverse acoustic phonons behave as expected, the in-plane transverse acoustic phonons reveal considerable softening on cooling to T_{s} and then harden on approaching T_{N} before saturating below T_{N}. In addition, we find that spin-spin correlation lengths of low-energy magnetic excitations within the FeAs layer and along the c axis increase dramatically below T_{s} and show a weak anomaly across T_{N}. These results suggest that the electronic nematic phase present in the paramagnetic tetragonal phase is closely associated with dynamic spin-lattice coupling, possibly arising from the one-phonon–two-magnon mechanism.

  16. Solid state proton spin-lattice relaxation in four structurally related organic molecules

    International Nuclear Information System (INIS)

    Beckmann, Peter A.; Burbank, Kendra S.; Lau, Matty M.W.; Ree, Jessica N.; Weber, Tracy L.

    2003-01-01

    We report and interpret the temperature dependence of the proton spin-lattice relaxation rate at 8.50 and 22.5 MHz in four polycrystalline solids composed of structurally related molecules: 2-ethylanthracene, 2-t-butylanthracene, 2-ethylanthraquinone, and 2-t-butylanthraquinone. We have been unable to grow single crystals and therefore do not know the crystal structures. Hence, we use the NMR relaxometry data to make predictions about the solid state structures. As expected, we are able to conclude that the ethyl groups do not reorient in the solid state but that the t-butyl groups do. The anthraquinones have a ''simpler'' structure than the anthracenes. The best dynamical models suggest that there is a unique crystallographic site for the t-butyl groups in 2-t-butylanthraquinone and two sites, each with half the molecules, for the ethyl groups in 2-ethylanthraquinone. There are also two sites in 2-ethylanthracene, but with unequal weights, suggesting four sites in the unit cell with lower symmetry than the two anthraquinones. Finally, the observed relaxation rate data in 2-t-butylanthracene is very complex and its interpretation demonstrates the uniqueness problem that arises in interpreting relaxometry data without the knowledge of the crystal structure

  17. Magnetization and 13C NMR spin-lattice relaxation of nanodiamond powder

    Energy Technology Data Exchange (ETDEWEB)

    Levin, E.M.; Fang, X.W.; Bud' ko, S.L.; Straszheim, W.E.; McCallum, R.W.; Schmidt-Rohr, K.

    2008-02-15

    The bulk magnetization at temperatures of 1.8-400 K and in magnetic fields up to 70 kOe, the ambient temperature {sup 13}C NMR spin-lattice relaxation, T{sub 1,c}, and the elemental composition of three nanodiamond powder samples have been studied. The total magnetization of nanodiamond can be explained in terms of contributions from (1) the diamagnetic effect of carbon, (2) the paramagnetic effect of unpaired electrons present in nanodiamond grains, and (3) ferromagnetic-like and (4) superparamagnetic contributions from Fe-containing particles detected in spatially resolved energy-dispersive spectroscopy. Contributions (1) and (2) are intrinsic to nanodiamond, while contributions (3) and (4) arise from impurities naturally present in detonation nanodiamond samples. {sup 13}C NMR T{sub 1,c} relaxation would be unaffected by the presence of the ferromagnetic particles with the bulk magnetization of {approx} 0.01 emu/g at 300 K. Thus, a reduction of T{sub 1,c} by 3 orders of magnitude compared to natural and synthetic microdiamonds confirms the presence of unpaired electrons in the nanodiamond grains. The spin concentration in nanodiamond powder corresponds to {approx}30 unpaired electrons per {approx}4.6 nm diameter nanodiamond grain.

  18. Interaction study of polyisobutylene with paraffins by NMR using the evaluation of spin-lattice relaxation times for hydrogen nuclei

    International Nuclear Information System (INIS)

    Marques, Rosana G.G.; Tavares, Maria I.B.

    2001-01-01

    The evaluation of spin-lattice relaxation times of 1 H for polyisobutylene/paraffin systems, were obtained using the classic inversion recovery technique, and also through Cross Polarization Magic Angle Spinning (CP/MAS) techniques varying the contact time and also by the delayed contact time pulse sequence. NMR results showed that the polyisobutylene/paraffin systems in which high molecular weight paraffins were used, is heterogeneous. However, for paraffins with low molecular weight, the system presents good homogeneity. (author)

  19. Quantum mechanical alternative to Arrhenius equation in the interpretation of proton spin-lattice relaxation data for the methyl groups in solids

    KAUST Repository

    Bernatowicz, Piotr; Shkurenko, Aleksander; Osior, Agnieszka; Kamieński, Bohdan; Szymański, Sławomir

    2015-01-01

    Theory of nuclear spin-lattice relaxation in methyl groups in solids has been a recurring problem in nuclear magnetic resonance (NMR) spectroscopy. The current view is that, except for extreme cases of low torsional barriers where special quantum

  20. Spin Diffusion and Spin Lattice Relaxation of Dipolar Order in Solids Containing Paramagnetic Impurities

    International Nuclear Information System (INIS)

    Furman, G.B.; Panich, A.M.; Goren, S.D.

    1998-01-01

    The phenomena of spin diffusion and spin lattice relaxation of nuclear dipolar order in solids containing paramagnetic impurities (PI) is considered. We show that at the beginning of the relaxation process the diffusion vanishing regime realizes with non-exponential time dependence, R(t) ∼ exp [- (t/T 1d ) α ], where T 1d ∼ C p -1/α , C p is PI's concentration. For a homogeneous distribution of Pis and nuclear spins, α=Q/6, where Q is the sample dimensionality; for an inhomogeneous distribution, the sample is divided into q-dimensional subsystems, each containing one PI, yield- ing α= (Q + q) /6. This result coincides with experimental data for CaF 2 doped with 0.8 - 10 -3 ωt % of Mn 2+ , where the non-exponential decay of the dipolar signal with α= 0.83 has been observed [3]. Fitting the experimental data yields a good agreement with T 1d = 66 ms . For another independent check of the obtained results we use dependence of the relaxation time on impurities concentration. In accordance that 1/α=1.2 , we have T 1d ∼ C p -1 '. 2 . Exactly this dependence on impurity concentration of the relaxation time has been found in the experiment. Then the relaxation regime starts as a non-exponential time dependent, proceed asymptotically to an to an exponential function of time, to so called diffusion limited relaxation regime with relaxation time T 1d D is inversely depends on impurities concentration. This kind of relaxation behavior of the dipolar order takes place in the experiment [2]. Using experimental results [2] from this two regime we can estimate the diffusion coefficient of the nuclear dipolar order in CaF 2 , which gives for typical values of impurity concentration C p ∼ 10 18 cm 3 the diffusion coefficient of dipolar order in the interval D ∼ 10 -11 -i- 10 -12 cm 2 /sec which is coincide to the case of Zeeman energy spin diffusion

  1. Electron spin-lattice relaxation of low-symmetry Ni.sup.2+./sup. centers in LiF

    Czech Academy of Sciences Publication Activity Database

    Azamat, Dmitry; Badalyan, A. G.; Dejneka, Alexandr; Jastrabík, Lubomír; Lančok, Ján

    2014-01-01

    Roč. 104, č. 25 (2014), "252902-1"-"252902-4" ISSN 0003-6951 R&D Projects: GA MŠk(CZ) LM2011029; GA TA ČR TA01010517; GA ČR GAP108/12/1941 Grant - others:SAFMAT(XE) CZ.2.16/3.1.00/22132 Institutional support: RVO:68378271 Keywords : Ni 2+ centers * LiF single crystals * electron spin-lattice relaxation * electron spin echo technique Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.302, year: 2014

  2. Temperature dependence of electron spin-lattice relaxation of radiation-produced silver atoms in polycrystalline aqueous and glassy organic matrices. Importance of relaxation by tunneling modes in disordered matrices

    International Nuclear Information System (INIS)

    Michalik, J.; Kevan, L.

    1978-01-01

    The electron spin-lattice relaxation of trapped silver atoms in polycrystalline ice matrices and in methanol, ethanol, propylene carbonate, and 2-methyltetrahydrofuran organic glasses has been directly studied as a function of temperature by the saturation-recovery method. Below 40 K the dominant electron spin-lattice relaxation mechanism involves modulation of the electron nuclear dipolar interaction with nuclei in the radical's environment by tunneling of those nuclei between two nearly equal energy configurations. This relaxation mechanism occurs with high efficiency, has a characteristic linear temperature dependence, and is typically found in highly disordered matrices. The efficiency of this relaxation mechanism seems to decrease with decreasing polarity of the matrix. Deuteration experiments show that the tunneling nuclei are protons and in methanol it is shown that the methyl protons have more tunneling modes available than the hydroxyl protons. In polycrystalline ice matrices silver atoms can be stabilized with two different orientations of surrounding water molecules; the efficiency of the tunneling relaxation reflects this difference. From these and previous results on tunneling relaxation of trapped electrons in glassy matrices it appears that tunneling relaxation may be used to distinguish models with different geometrical configurations and to determine the relative rigidity of such configurations around trapped radicals in disordered solids. (author)

  3. Effects of hydrostatic pressure on spin-lattice coupling in two-dimensional ferromagnetic Cr2Ge2Te6

    Science.gov (United States)

    Sun, Y.; Xiao, R. C.; Lin, G. T.; Zhang, R. R.; Ling, L. S.; Ma, Z. W.; Luo, X.; Lu, W. J.; Sun, Y. P.; Sheng, Z. G.

    2018-02-01

    Spin-lattice coupling plays an important role in both formation and understanding of the magnetism in two-dimensional magnetic semiconductors (2DMS). In this paper, the steady pressure effects on the lattice structure, Raman resonances, and magnetization of a 2DMS Cr2Ge2Te6 have been studied by both experiments and first principles calculations. It is found that the bond length of Cr-Cr decreases, the angle of Cr-Te-Cr diverges from 90°, and the Raman modes Eg3 and Ag1 show an increase with the application of external pressure. Consequently, the magnetic phase transition temperature TC decreases from 66.6 K to 60.6 K (˜9%) as the pressure increases from 0 to 1 GPa. These pressure effects not only confirm the existence of strong spin-lattice coupling but also reveal the detailed information about the lattice deformation effect on the magnetic properties in such 2DMS, which would be a benefit for the further understanding and manipulation of the magnetism in 2D materials.

  4. Anisotropy of the proton spin--lattice relaxation time in the superconducting intercalation complex TaS2(NH3): Structural and bonding implications

    International Nuclear Information System (INIS)

    Gamble, F.R.; Silbernagel, B.G.

    1975-01-01

    The nature of the interaction responsible for the formation of molecular intercalation complexes between Lewis bases and layered transition metal dichalcogenides is not well understood. To some extent this is due to a lack of structural information. A prototype of these complexes is TaS 2 (NH 3 ), in which monolayers of ammonia are inserted between the metallic, superconducting layers of TaS 2 . The compound is crystalline and stoichiometric. Measurement of the anisotropy of the proton spin--lattice relaxation time at 300 degreeK indicates that the molecular threefold symmetry axis is not perpendicular to the disulfide layers as suggested by other workers, but is parallel to the layers. This orientation precludes direct interaction between the molecular lone pair orbital and the transition metal atoms. The interactions governing the structure of this complex may be similar to those obtaining in the intercalation complexes between TaS 2 and a number of substituted pyridines, in which complexes the axis of the lone pair orbital is also parallel to the layers

  5. Study on frugmentation of one-quasiparticle and one-phonon states in the quasiparticle-phonon nuclear model

    International Nuclear Information System (INIS)

    Solov'ev, V.G.

    1980-01-01

    The general assumptions of the quasiparticle-phonon nuclear model are given. This model describes the few-quasiparticle components of the wave functions at low, intermediate and high excitation energies. The method of strength functions which plays a key role in describing complex nuclei is also presented. A further development of the quasiparticle-phonon nuclear model is outlined. The fragmentation of one-quasiparticle and one-phonon states over nuclear levels is studied. The results on the fragmentation of deep hole states in spherical nuclei are presented, which describe well the experimental data. The neutron strength functions and their spin dependence are calculated. A good agreement with experiment is obtained. The energies and widths of the giant resonances are calculated in spherical and deformed nuclei. The information on the many-quasiparticle components of excited state wave functions is shown to be very scarce. The necessity of studying the few-quasiparticle configurations is pointed out

  6. A study of spin-lattice relaxation rates of glucose, fructose, sucrose and cherries using high-T c SQUID-based NMR in ultralow magnetic fields

    Science.gov (United States)

    Liao, Shu-Hsien; Wu, Pei-Che

    2017-08-01

    We study the concentration dependence of spin-lattice relaxation rates, T 1 -1, of glucose, fructose, sucrose and cherries by using high-T c SQUID-based NMR at magnetic fields of ˜97 μT. The detected NMR signal, Sy (T Bp), is fitted to [1 - exp(-T Bp/T 1)] to derive T 1 -1, where Sy (T Bp) is the strength of the NMR signal, T Bp is the duration of pre-polarization and T 1 -1 is the spin-lattice relaxation rate. It was found that T 1 -1 increases as the sugar concentrations increase. The increased T 1 -1 is due to the presence of more molecules in the surroundings, which increases the spin-lattice interaction and in turn enhances T 1 -1. The T 1 -1 versus degrees Brix curve provides a basis for determining unknown Brix values for cherries as well as other fruits.

  7. Duchenne muscular dystrophy carriers. Proton spin-lattice relaxation times of skeletal muscles on magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsumura, K.; Nakano, I. (Shimoshizu National Hospital, Chiba (Japan). Dept. of Neurology); Fukuda, N.; Ikehira, H.; Tateno, Y. (National Inst. of Radiological Sciences, Chiba (Japan). Div. of Clinical Research); Aoki, Y. (National Inst. of Radiological Sciences, Chiba (Japan))

    1989-11-01

    By means of magnetic resonance imaging (MRI), the proton spin-lattice relaxation times (T1 values) of the skeletal muscles were measured in Duchenne muscular dystrophy (DMD) carriers and normal controls. The bound water fraction (BWF) was calculated from the T1 values obtained, according to the fast proton diffusion model. In the DMD carriers, T1 values of the gluteus maximus and quadriceps femoris muscles were significantly higher, and BWFs of these muscles were significantly lower than in normal control. Degenerative muscular changes accompanied by interstitial edema were presumed responsible for this abnormality. No correlation was observed between the muscle T1 and serum creatine kinase values. The present study showed that MRI could be a useful method for studying the dynamic state of water in both normal and pathological skeletal muscles. Its possible utility for DMD carrier detection was discussed briefly. (orig.).

  8. Measurement of solute proton spin-lattice relaxation times in water using the 1,3,3,1 sequence

    International Nuclear Information System (INIS)

    Sankar, S.S.; Mole, P.A.; Coulson, R.L.

    1986-01-01

    1 H NMR spin-lattice relaxation times (T1) of the N-CH3 proton resonances of phosphocreatine (PCr) and creatine (Cr) in water solutions were obtained using the 1,3,3,1 pulse sequence. These T1 values were equivalent to those obtained in D 2 O and water using either the conventional inversion-recovery experiment or the 1,3,3,1 pulse sequence. Thus, the 1,3,3,1 sequence of proton NMR can provide an independent means along with phosphorous NMR for assess PCr and for the study of the creatine kinase reaction (PCr + ADP in equilibrium ATP + Cr) in aqueous solutions and perhaps in biological preparations

  9. NMR water-proton spin-lattice relaxation time of human red blood cells and red blood cell suspensions

    International Nuclear Information System (INIS)

    Sullivan, S.G.; Rosenthal, J.S.; Winston, A.; Stern, A.

    1988-01-01

    NMR water-proton spin-lattice relaxation times were studied as probes of water structure in human red blood cells and red blood cell suspensions. Normal saline had a relaxation time of about 3000 ms while packed red blood cells had a relaxation time of about 500 ms. The relaxation time of a red blood cell suspension at 50% hematocrit was about 750 ms showing that surface charges and polar groups of the red cell membrane effectively structure extracellular water. Incubation of red cells in hypotonic saline increases relaxation time whereas hypertonic saline decreases relaxation time. Relaxation times varied independently of mean corpuscular volume and mean corpuscular hemoglobin concentration in a sample population. Studies with lysates and resealed membrane ghosts show that hemoglobin is very effective in lowering water-proton relaxation time whereas resealed membrane ghosts in the absence of hemoglobin are less effective than intact red cells. 9 refs.; 3 figs.; 1 table

  10. Differential saturation study of radial and angular modulation mechanisms of electron spin--lattice relaxation for trapped hydrogen atoms in sulfuric acid glasses. [X radiation

    Energy Technology Data Exchange (ETDEWEB)

    Plonka, A; Kevan, L

    1976-11-01

    A differential ESR saturation study of allowed transitions and forbidden proton spin-flip satellite transitions for trapped hydrogen atoms in sulfuric acid glasses indicates that angular modulation dominates the spin-lattice relaxation mechanisms and suggests that the modulation arises from motion of the H atom.

  11. An NMR thermometer for cryogenic magic-angle spinning NMR: The spin-lattice relaxation of 127I in cesium iodide

    Science.gov (United States)

    Sarkar, Riddhiman; Concistrè, Maria; Johannessen, Ole G.; Beckett, Peter; Denning, Mark; Carravetta, Marina; al-Mosawi, Maitham; Beduz, Carlo; Yang, Yifeng; Levitt, Malcolm H.

    2011-10-01

    The accurate temperature measurement of solid samples under magic-angle spinning (MAS) is difficult in the cryogenic regime. It has been demonstrated by Thurber et al. (J. Magn. Reson., 196 (2009) 84-87) [10] that the temperature dependent spin-lattice relaxation time constant of 79Br in KBr powder can be useful for measuring sample temperature under MAS over a wide temperature range (20-296 K). However the value of T1 exceeds 3 min at temperatures below 20 K, which is inconveniently long. In this communication, we show that the spin-lattice relaxation time constant of 127I in CsI powder can be used to accurately measure sample temperature under MAS within a reasonable experimental time down to 10 K.

  12. Resonantly enhanced spin-lattice relaxation of Mn2 + ions in diluted magnetic (Zn,Mn)Se/(Zn,Be)Se quantum wells

    Science.gov (United States)

    Debus, J.; Ivanov, V. Yu.; Ryabchenko, S. M.; Yakovlev, D. R.; Maksimov, A. A.; Semenov, Yu. G.; Braukmann, D.; Rautert, J.; Löw, U.; Godlewski, M.; Waag, A.; Bayer, M.

    2016-05-01

    The dynamics of spin-lattice relaxation in the magnetic Mn2 + ion system of (Zn,Mn)Se/(Zn,Be)Se quantum-well structures are studied using optical methods. Pronounced cusps are found in the giant Zeeman shift of the quantum-well exciton photoluminescence at specific magnetic fields below 10 T, when the Mn spin system is heated by photogenerated carriers. The spin-lattice relaxation time of the Mn ions is resonantly accelerated at the cusp magnetic fields. Our theoretical analysis demonstrates that a cusp occurs at a spin-level mixing of single Mn2 + ions and a quick-relaxing cluster of nearest-neighbor Mn ions, which can be described as intrinsic cross-relaxation resonance within the Mn spin system.

  13. Enhanced 29Si spin-lattice relaxation and observation of three-dimensional lattice connectivity in zeolites by two-dimensional 29Si MASS NMR

    International Nuclear Information System (INIS)

    Sivadinarayana, C.; Choudhary, V.R.; Ganapathy, S.

    1994-01-01

    It is shown that considerable sensitivity enhancement is achieved in the 29 Si magic angle sample spinning (MASS) NMR spectra of highly siliceous zeolites by pre treating the material with oxygen. The presence of adsorbed molecular oxygen in zeolite channels promotes an efficient 29 Si spin-lattice relaxation via a paramagnetic interaction between the lattice 29 Si T-site and the adsorbed oxygen on zeolite channels. This affords an efficient 2-D data collection and leads to increased sensitivity. The utility of this method is demonstrated in a two-dimensional COSY-45 NMR experiment of a high silica zeolite ZSM-5. (author). 20 refs., 3 figs., 1 tab

  14. $^{11}$B and $^{27}$Al NMR spin-lattice relaxation and Knight shift study of Mg$_{1-x}$Al$_x$B$_2$. Evidence for anisotropic Fermi surface

    OpenAIRE

    Papavassiliou, G.; Pissas, M.; Karayanni, M.; Fardis, M.; Koutandos, S.; Prassides, K.

    2002-01-01

    We report a detailed study of $^{11}$B and $^{27}$Al NMR spin-lattice relaxation rates ($1/T_1$), as well as of $^{27}$Al Knight shift (K) of Mg$_{1-x}$Al$_x$B$_2$, $0\\leq x\\leq 1$. The obtained ($1/T_1T$) and K vs. x plots are in excellent agreement with ab initio calculations. This asserts experimentally the prediction that the Fermi surface is highly anisotropic, consisting mainly of hole-type 2-D cylindrical sheets from bonding $2p_{x,y}$ boron orbitals. It is also shown that the density ...

  15. A quantum mechanical alternative to the Arrhenius equation in the interpretation of proton spin-lattice relaxation data for the methyl groups in solids.

    Science.gov (United States)

    Bernatowicz, Piotr; Shkurenko, Aleksander; Osior, Agnieszka; Kamieński, Bohdan; Szymański, Sławomir

    2015-11-21

    The theory of nuclear spin-lattice relaxation in methyl groups in solids has been a recurring problem in nuclear magnetic resonance (NMR) spectroscopy. The current view is that, except for extreme cases of low torsional barriers where special quantum effects are at stake, the relaxation behaviour of the nuclear spins in methyl groups is controlled by thermally activated classical jumps of the methyl group between its three orientations. The temperature effects on the relaxation rates can be modelled by Arrhenius behaviour of the correlation time of the jump process. The entire variety of relaxation effects in protonated methyl groups have recently been given a consistent quantum mechanical explanation not invoking the jump model regardless of the temperature range. It exploits the damped quantum rotation (DQR) theory originally developed to describe NMR line shape effects for hindered methyl groups. In the DQR model, the incoherent dynamics of the methyl group include two quantum rate (i.e., coherence-damping) processes. For proton relaxation only one of these processes is relevant. In this paper, temperature-dependent proton spin-lattice relaxation data for the methyl groups in polycrystalline methyltriphenyl silane and methyltriphenyl germanium, both deuterated in aromatic positions, are reported and interpreted in terms of the DQR model. A comparison with the conventional approach exploiting the phenomenological Arrhenius equation is made. The present observations provide further indications that incoherent motions of molecular moieties in the condensed phase can retain quantum character over much broader temperature range than is commonly thought.

  16. Quantum mechanical alternative to Arrhenius equation in the interpretation of proton spin-lattice relaxation data for the methyl groups in solids

    KAUST Repository

    Bernatowicz, Piotr

    2015-10-01

    Theory of nuclear spin-lattice relaxation in methyl groups in solids has been a recurring problem in nuclear magnetic resonance (NMR) spectroscopy. The current view is that, except for extreme cases of low torsional barriers where special quantum effects are at stake, the relaxation behaviour of the nuclear spins in methyl groups is controlled by thermally activated classical jumps of the methyl group between its three orientations. The temperature effects on the relaxation rates can be modelled by Arrhenius behaviour of the correlation time of the jump process. The entire variety of relaxation effects in protonated methyl groups has recently been given a consistently quantum mechanical explanation not invoking the jump model regardless of the temperature range. It exploits the damped quantum rotation (DQR) theory originally developed to describe NMR line shape effects for hindered methyl groups. In the DQR model, the incoherent dynamics of the methyl group include two quantum rate, i.e., coherence-damping processes. For proton relaxation only one of these processes is relevant. In this paper, temperature-dependent proton spin-lattice relaxation data for the methyl groups in polycrystalline methyltriphenyl silane and methyltriphenyl germanium, both deuterated in aromatic positions, are reported and interpreted in terms of the DQR model. A comparison with the conventional approach exploiting the phenomenological Arrhenius equation is made. The present observations provide further indications that incoherent motions of molecular moieties in condensed phase can retain quantum character over much broad temperature range than is commonly thought.

  17. Excitation strengths and transition radii differences of one-phonon quadrupole excitations from electron scattering on {sup 92,94}Zr and {sup 94}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Sheikh Obeid, Abdulrahman

    2014-11-01

    In the framework of this thesis electron scattering experiments on low-energy excitations of {sup 92}Zr and {sup 94}Zr were performed at the S-DALINAC in a momentum transfer range q=0.3-0.6 fm{sup -1}. The nature of one-phonon symmetric and mixed-symmetric 2{sup +} and 3{sup -} states of {sup 92}Zr was investigated by comparison with predictions of the quasi-particle phonon model (QPM). Theoretical (e,e') cross sections have been calculated within the distorted wave Born approximation (DWBA) to account for Coulomb distortion effects. The reduced strengths of the one-quadrupole phonon states and the one-octupole phonon state have been extracted. The similarity of the momentum-transfer dependence of the form factors between the 2{sup +} states supports the one-phonon nature of the 2{sup +}{sub 2} state of {sup 92}Zr. A new method based on the Plane Wave Born Approximation (PWBA) for a model-independent determination of the ratio of the E2 transition strengths of fully symmetric (FSS) and mixed-symmetry (MSS) one-phonon excitations of heavy vibrational nuclei is introduced. Due to the sensitivity of electron scattering to charge distributions, the charge transition-radii difference can be determined. The basic assumptions (independence from the ratio of Coulomb corrections and from absolute values of transition radii) are tested within the Tassie model, which makes no specific assumptions about the structure of the states other than collectivity. It is shown that a PWBA analysis of the form factors, which usually fails for heavy nuclei, can nevertheless be applied in a relative analysis. This is a new promising approach to determine the ground state transition strength of the 2{sup +} MSS of vibrational nuclei with a precision limited only by the experimental information about the B(E2;2{sup +}{sub 1}→0{sup +}{sub 1}) strength. The PWBA approach furthermore provides information about differences of the proton transition radii of the respective states

  18. Investigation of the spin-lattice coupling in M n3G a1 -xS nxN antiperovskites

    Science.gov (United States)

    Shi, Kewen; Sun, Ying; Colin, Claire V.; Wang, Lei; Yan, Jun; Deng, Sihao; Lu, Huiqing; Zhao, Wenjun; Kazunari, Yamaura; Bordet, Pierre; Wang, Cong

    2018-02-01

    The magnetovolume effects (MVEs) of M n3G a1 -xS nxN antiperovskite compounds have been investigated by means of neutron powder diffraction. Increasing the Sn-doping content at the Ga site leads to the broadening of the magnetic phase transition temperature range and the thermal expansion behavior changes from negative to positive. We establish the relationship between the square of the ordered magnetic moment m2 and the volume variation Δ ωm for the antiferromagnetic phase (Γ5 g magnetic structure with rhombohedral symmetry R 3 ¯m ). The temperature variations of Δ ωm(T ) , m2(T ) and the magnetoelastic coupling constant C (T ) are also quantitatively analyzed according to the itinerant-electron theory. Moreover, the increase of the phonon contribution to the thermal expansion induced by Sn doping and the corresponding decrease of dm/dT are revealed to be the key parameters for tuning the MVEs. Our results allow elucidating and quantifying the mechanism of the spin-lattice coupling and can be used to design magnetic functional materials with controlled thermal expansion behaviors for specific applications.

  19. Magneto-optical measurement of spin-lattice relaxation time in KBr and in the Na and Cs halogenetes and Co++ ion magnetic circular dichroism study in KCl

    International Nuclear Information System (INIS)

    Carvalho, R.A.

    1977-01-01

    A magnetic circular dicroism spectrometer is described, which was used in the following experiments: 1) The spin-lattice relaxation time (T 1 ) for F centers in NaCl, NaBr, CsBr and CsCl, at 1,8 0 K in magnetic fields up to 15000Gs is described. The suitability of the theory of ref. (08) to explain the differences observed for halides of differents alkali ions as well as for different structures is verified proves that the hyperfine interaction is the most important mechanism for this kind of centers. It is also verified that, for temperatures between 6 0 K and 15 0 K, T 1 experimental values fits the theory of ref. (21) reasonably well, for F centers in KBr. This theory us an extension of that of ref. (8). 2) The MCD spectra for KCl:Co ++ and Caf 2 :Co ++ in different magnetic fields up to 56KGs, and in temperature range between 1,8 0 K and 4,2 0 K is obtained. The results are consistent with the assumption that Co ++ centers are intersticial in KCl lattice [pt

  20. Interaction study of polyisobutylene with paraffins by NMR using the evaluation of spin-lattice relaxation times for hydrogen nuclei; Estudo da interacao do poliisobutileno com parafinas por RMN no estado solido

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Rosana G.G. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas - CENPES]. E-mail: garrido@cenpes.petrobras.com.br; Tavares, Maria I.B. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas]. E-mail: mibt@ima.ufrj.br

    2001-07-01

    The evaluation of spin-lattice relaxation times of {sup 1}H for polyisobutylene/paraffin systems, were obtained using the classic inversion recovery technique, and also through Cross Polarization Magic Angle Spinning (CP/MAS) techniques varying the contact time and also by the delayed contact time pulse sequence. NMR results showed that the polyisobutylene/paraffin systems in which high molecular weight paraffins were used, is heterogeneous. However, for paraffins with low molecular weight, the system presents good homogeneity. (author)

  1. Quantum-optical magnets with competing short- and long-range interactions: Rydberg-dressed spin lattice in an optical cavity

    Directory of Open Access Journals (Sweden)

    Jan Gelhausen, Michael Buchhold, Achim Rosch, Philipp Strack

    2016-10-01

    Full Text Available The fields of quantum simulation with cold atoms [1] and quantum optics [2] are currently being merged. In a set of recent pathbreaking experiments with atoms in optical cavities [3,4] lattice quantum many-body systems with both, a short-range interaction and a strong interaction potential of infinite range -mediated by a quantized optical light field- were realized. A theoretical modelling of these systems faces considerable complexity at the interface of: (i spontaneous symmetry-breaking and emergent phases of interacting many-body systems with a large number of atoms $N\\rightarrow\\infty$, (ii quantum optics and the dynamics of fluctuating light fields, and (iii non-equilibrium physics of driven, open quantum systems. Here we propose what is possibly the simplest, quantum-optical magnet with competing short- and long-range interactions, in which all three elements can be analyzed comprehensively: a Rydberg-dressed spin lattice [5] coherently coupled to a single photon mode. Solving a set of coupled even-odd sublattice Master equations for atomic spin and photon mean-field amplitudes, we find three key results. (R1: Superradiance and a coherent photon field can coexist with spontaneously broken magnetic translation symmetry. The latter is induced by the short-range nearest-neighbor interaction from weakly admixed Rydberg levels. (R2: This broken even-odd sublattice symmetry leaves its imprint in the light via a novel peak in the cavity spectrum beyond the conventional polariton modes. (R3: The combined effect of atomic spontaneous emission, drive, and interactions can lead to phases with anomalous photon number oscillations. Extensions of our work include nano-photonic crystals coupled to interacting atoms and multi-mode photon dynamics in Rydberg systems.

  2. Combined Fat Imaging/Look Locker for mapping of lipid spin-lattice (T1) relaxation time

    Science.gov (United States)

    Jihyun Park, Annie; Yung, Andrew; Kozlowski, Piotr; Reinsberg, Stefan

    2012-10-01

    Tumor hypoxia is a main problem arising in the treatment of cancer due to its resistance to cytotoxic therapy such as radiation and chemotherapy, and selection for more aggressive tumor phenotypes. Attempts to improve and quantify tumor oxygenation are in development and tools to assess the success of such schemes are required. Monitoring oxygen level with MRI using T1 based method (where oxygen acts as T1 shortening agent) is a dynamic and noninvasive way to study tumor characteristics. The method's sensitivity to oxygen is higher in lipids than in water due to higher oxygen solubility in lipid. Our study aims to develop a time-efficient method to spatially map T1 of fat inside the tumor. We are combining two techniques: Fat/Water imaging and Look Locker (a rapid T1 measurement technique). Fat/Water Imaging is done with either Dixon or Direct Phase Encoding (DPE) method. The combination of these techniques poses new challenges that are tackled using spin dynamics simulations as well as experiments in vitro and in vivo.

  3. Nuclear Spin Lattice Relaxation and Conductivity Studies of the Non-Arrhenius Conductivity Behavior in Lithium Fast Ion Conducting Sulfide Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Benjamin Michael [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    As time progresses, the world is using up more of the planet's natural resources. Without technological advances, the day will eventually arrive when these natural resources will no longer be sufficient to supply all of the energy needs. As a result, society is seeing a push for the development of alternative fuel sources such as wind power, solar power, fuel cells, and etc. These pursuits are even occurring in the state of Iowa with increasing social pressure to incorporate larger percentages of ethanol in gasoline. Consumers are increasingly demanding that energy sources be more powerful, more durable, and, ultimately, more cost efficient. Fast Ionic Conducting (FIC) glasses are a material that offers great potential for the development of new batteries and/or fuel cells to help inspire the energy density of battery power supplies. This dissertation probes the mechanisms by which ions conduct in these glasses. A variety of different experimental techniques give a better understanding of the interesting materials science taking place within these systems. This dissertation discusses Nuclear Magnetic Resonance (NMR) techniques performed on FIC glasses over the past few years. These NMR results have been complimented with other measurement techniques, primarily impedance spectroscopy, to develop models that describe the mechanisms by which ionic conduction takes place and the dependence of the ion dynamics on the local structure of the glass. The aim of these measurements was to probe the cause of a non-Arrhenius behavior of the conductivity which has been seen at high temperatures in the silver thio-borosilicate glasses. One aspect that will be addressed is if this behavior is unique to silver containing fast ion conducting glasses. more specifically, this study will determine if a non-Arrhenius correlation time, τ, can be observed in the Nuclear Spin Lattice Relaxation (NSLR) measurements. If so, then can this behavior be modeled with a new single

  4. Spin Lattice Relaxation EPR pO2 Images May Direct the Location of Radiation Tumor Boosts to Enhance Tumor Cure.

    Science.gov (United States)

    Epel, Boris; Krzykawska-Serda, Martyna; Tormyshev, Victor; Maggio, Matthew C; Barth, Eugene D; Pelizzari, Charles A; Halpern, Howard J

    2017-12-01

    Radiation treatment success and high tumor oxygenation and success have been known to be highly correlated. This suggests that radiation therapy guided by images of tumor regions with low oxygenation, oxygen-guided radiation therapy (OGRT) may be a promising enhancement of cancer radiation treatment. Before applying the technique to human subjects, OGRT needs to be tested in animals, most easily in rodents. Electron paramagnetic resonance imaging provides quantitative maps of tissue and tumor oxygen in rodents with 1 mm spatial resolution and 1 torr pO 2 resolution at low oxygen levels. The difficulty of using mouse models is their small size and that of their tumors. To overcome this we used XRAD225Cx micro-CT/ therapy system and 3D printed conformal blocks. Radiation is delivered first to a uniform 15% tumor control dose for the whole tumor and then a boost dose to either hypoxic tumor regions or equal volumes of well oxygenated tumor. Delivery of the booster dose used a multiple beam angles to deliver radiation beams whose shape conforms to that of all hypoxic regions or fully avoids those regions. To treat/avoid all hypoxic regions we used individual radiation blocks 3D-printed from acrylonitrile butadiene styrene polymer infused with tungsten particles fabricated immediately after imaging to determine regions with pO 2 less than 10 torr. Preliminary results demonstrate the efficacy of the radiation treatment with hypoxic boosts with syngeneic FSa fibrosarcoma tumors in the legs of C3H mice.

  5. Solid state {sup 1}H spin-lattice relaxation and isolated-molecule and cluster electronic structure calculations in organic molecular solids: The relationship between structure and methyl group and t-butyl group rotation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianlong, E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, 4 North Jianshe Rd., 2nd Section, Chengdu 610054 (China); Mallory, Frank B. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Mallory, Clelia W. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 (United States); Odhner, Hosanna R.; Beckmann, Peter A., E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Department of Physics, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States)

    2014-05-21

    We report ab initio density functional theory electronic structure calculations of rotational barriers for t-butyl groups and their constituent methyl groups both in the isolated molecules and in central molecules in clusters built from the X-ray structure in four t-butyl aromatic compounds. The X-ray structures have been reported previously. We also report and interpret the temperature dependence of the solid state {sup 1}H nuclear magnetic resonance spin-lattice relaxation rate at 8.50, 22.5, and 53.0 MHz in one of the four compounds. Such experiments for the other three have been reported previously. We compare the computed barriers for methyl group and t-butyl group rotation in a central target molecule in the cluster with the activation energies determined from fitting the {sup 1}H NMR spin-lattice relaxation data. We formulate a dynamical model for the superposition of t-butyl group rotation and the rotation of the t-butyl group's constituent methyl groups. The four compounds are 2,7-di-t-butylpyrene, 1,4-di-t-butylbenzene, 2,6-di-t-butylnaphthalene, and 3-t-butylchrysene. We comment on the unusual ground state orientation of the t-butyl groups in the crystal of the pyrene and we comment on the unusually high rotational barrier of these t-butyl groups.

  6. Features of the non-collinear one-phonon anomalous light scattering controlled by elastic waves with elevated linear losses: potentials for multi-frequency parallel spectrum analysis of radio-wave signals.

    Science.gov (United States)

    Shcherbakov, Alexandre S; Arellanes, Adan Omar

    2017-12-01

    During subsequent development of the recently proposed multi-frequency parallel spectrometer for precise spectrum analysis of wideband radio-wave signals, we study potentials of new acousto-optical cells exploiting selected crystalline materials at the limits of their capabilities. Characterizing these wide-aperture cells is non-trivial due to new features inherent in the chosen regime of an advanced non-collinear one-phonon anomalous light scattering by elastic waves with significantly elevated acoustic losses. These features can be observed simpler in uniaxial, tetragonal, and trigonal crystals possessing linear acoustic attenuation. We demonstrate that formerly studied additional degree of freedom, revealed initially for multi-phonon regimes of acousto-optical interaction, can be identified within the one-phonon geometry as well and exploited for designing new cells. We clarify the role of varying the central acoustic frequency and acoustic attenuation using the identified degree of freedom. Therewith, we are strongly restricted by a linear regime of acousto-optical interaction to avoid the origin of multi-phonon processes within carrying out a multi-frequency parallel spectrum analysis of radio-wave signals. Proof-of-principle experiments confirm the developed approaches and illustrate their applicability to innovative technique for an advanced spectrum analysis of wideband radio-wave signals with the improved resolution in an extended frequency range.

  7. Non-Arrhenius conductivity in the fast ionic conductor Li0.5La0.5TiO3: Reconciling spin-lattice and electrical-conductivity relaxations

    International Nuclear Information System (INIS)

    Leon, C.; Santamaria, J.; Paris, M.A.; Sanz, J.; Ibarra, J.; Torres, L.M.

    1997-01-01

    Nuclear magnetic resonance and electrical conductivity measurements are conducted to study the dynamics of the ionic diffusion process in the crystalline ionic conductor Li 0.5 La 0.5 TiO 3 . dc conductivity shows a non-Arrhenius temperature dependence, similar to the one recently reported for some ionic conducting glasses. Spin-lattice and conductivity relaxations are analyzed in the same frequency and temperature range in terms of the non-Arrhenius dependence of the correlation time. Both relaxations are then described using a single correlation function of the form f(t)=exp(-(t/τ) β ), with β=0.4 over the whole temperature range. copyright 1997 The American Physical Society

  8. Electron spin-lattice relaxation in fractals

    International Nuclear Information System (INIS)

    Shrivastava, K.N.

    1986-08-01

    We have developed the theory of the spin-fracton interaction for paramagnetic ions in fractal structures. The interaction is exponentially damped by the self-similarity length of the fractal and by the range dimensionality d Φ . The relaxation time of the spin due to the absorption and emission of the fracton has been calculated for a general dimensionality called the Raman dimensionality d R , which for the fractons differs from the Hausdorff (fractal) dimensionality, D, as well as from the Euclidean dimensionality, d. The exponent of the energy level separation in the relaxation rate varies with d R d Φ /D. We have calculated the spin relaxation rate due to a new type of Raman process in which one fracton is absorbed to affect a spin transition from one electronic level to another and later another fracton is emitted along with a spin transition such that the difference in the energies of the two fractons is equal to the electronic energy level separation. The temperature and the dimensionality dependence of such a process has been found in several approximations. In one of the approximations where the van Vleck relaxation rate for a spin in a crystal is known to vary with temperature as T 9 , our calculated variation for fractals turns out to be T 6.6 , whereas the experimental value for Fe 3+ in frozen solutions of myoglobin azide is T 6.3 . Since we used d R =4/3 and the fracton range dimensionality d Φ =D/1.8, we expect to measure the dimensionalities of the problem by measuring the temperature dependence of the relaxation times. We have also calculated the shift of the paramagnetic resonance transition for a spin in a fractal for general dimensionalities. (author)

  9. Spin lattice coupling in multiferroic hexagonal YMnO3

    Indian Academy of Sciences (India)

    phonon and spin waves involving deviations out of the spiral magnetic plane. This ... collimations were used to fully benefit from the focusing effects. ... following spin Hamiltonian based on the Heisenberg model H = JSiSj − hSini +. DSz i Sz.

  10. Spin-lattice effects in selected antiferromagnetic materials

    Czech Academy of Sciences Publication Activity Database

    Zherlitsyn, S.; Yasin, S.; Wosnitza, J.; Zvyagin, A.A.; Andreev, Alexander V.; Tsurkan, V.

    2014-01-01

    Roč. 40, č. 2 (2014), s. 123-133 ISSN 1063-777X R&D Projects: GA ČR GAP204/12/0150 Grant - others:AVČR(CZ) M100101203 Keywords : low-dimensional spin systems * frustrated chromium spinels * spin-strain interaction * uranium -based compounds Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.786, year: 2014

  11. Spin-orbit and spin-lattice coupling

    International Nuclear Information System (INIS)

    Bauer, Gerrit E.W.; Ziman, Timothy; Mori, Michiyasu

    2014-01-01

    We pursued theoretical research on the coupling of electron spins in the condensed matter to the lattice as mediated by the spin-orbit interaction with special focus on the spin and anomalous Hall effects. (author)

  12. The realization of Majorana fermions in Kitaev Quantum Spin Lattice

    Science.gov (United States)

    Do, Seung-Hwan; Park, Sang-Youn; Yoshitake, Junki; Nasu, Joji; Motome, Yukitoshi; Kwon, Y. S.; Adroja, D. T.; Voneshen, D.; Park, J.-H.; Choi, Kwang-Yong; Ji, Sungdae

    The Kitaev honeycomb lattice is envisioned as an ideal host for Majorana fermions that are created out of the spin liquid background. Combining specific heat and neutron scattering experiments with theoretical calculations, here, we establish a hitherto unparalleled spin fractionalization to two species of Majorana fermions in the Kitaev material α-RuCl3. The specific heat data unveil a two-stage release of magnetic entropy by (R/2)ln2 and the T-linear dependence at intermediate temperatures. Our inelastic neutron scattering measurements further corroborate two distinct characters of fractionalized excitations: an Y-like, dispersive, magnetic continuum at higher energies and a dispersionless excitation at low energies around the Brillouin zone center. These dual features are well described by a Ferromagnetic Kitaev model, providing a smoking gun proof of the itinerant and localized Majorana fermions emergent in Kitaev magnets.

  13. A direct measurement of g-factors in II-VI and III-V core-shell nanocrystals

    Science.gov (United States)

    Fradkin, L.; Langof, L.; Lifshitz, E.; Gaponik, N.; Rogach, A.; Eychmüller, A.; Weller, H.; Micic, O. I.; Nozik, A. J.

    2005-02-01

    This study describes a direct measurement of spectroscopic g-factors of photo-generated carriers in InP/ZnS and HgTe/Hg xCd 1-xTe(S) core-shell nanocrystals. The g-factor of trapped electrons and their spin-lattice versus radiative relaxation ratio ( T1/ τ) were measured by the use of continuous-wave and time-resolved optically detected magnetic resonance (ODMR) spectroscopy. The g-factors of excitons and donor-hole pairs were derived by the use of field-induced circular-polarized photoluminescence (CP-PL) spectroscopy. The combined information enabled to determine the g-factors of the individual band-edge electrons and holes. The results suggested an increase of the g-factor of the exciton and conduction electron with a decrease of the nanocrystal size.

  14. One phonon resonant Raman scattering in free-standing quantum wires

    International Nuclear Information System (INIS)

    Zhao, Xiang-Fu; Liu, Cui-Hong

    2007-01-01

    The scattering intensity (SI) of a free-standing cylindrical semiconductor quantum wire for an electron resonant Raman scattering (ERRS) process associated with bulk longitudinal optical (LO) phonon modes and surface optical (SO) phonon modes is calculated separately for T=0 K. The Frohlich interaction is considered to illustrate the theory for GaAs and CdS systems. Electron states are confined within a free-standing quantum wire (FSW). Single parabolic conduction and valence bands are assumed. The selection rules are studied. Numerical results and a discussion are also presented for various radii of the cylindrical

  15. Two- to one-phonon E3 transition strength in {sup 148}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Piiparinen, M [Niels Bohr Institute, Tandem Accelerator Laboratory, Roskilde (Denmark); [Jyvaeskylae Univ. (Finland). Dept. of Physics; Atac, A; Nyberg, J; Ramsoy, T; Sletten, G [Niels Bohr Institute, Tandem Acceleratory Laboratory, Roskile, (Denmark); Virtanen, A; Muller, D [Jyvaeskylae Univ. (Finland). Dept. of Physics; Kleinheinz, P [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Kernphysik; Blomqvist, J [Manne Siegbahn Inst. of Physics, Stockholm (Sweden)

    1992-08-01

    In a plunger experiment the mean life of the ({nu} f{sub 6}{sup 2}x3{sup -}x3{sup -})12{sup +} state at 3.981 MeV in {sub 64}{sup 148}Gd{sub 84} was measured as {tau}=83(10)ps, giving 77(11)B{sub w} for the 1286 keV 12{sup +} {yields} 9{sup -} E3 transition rate, which confirms the double-octupole character of the 12{sup +} state. The observed deviations in energy and transition rate from harmonic vibration are shown to be caused by the exclusion principle acting between nucleons in the two phonons and are related to the dominant contributions to the {sup 148}Gd octupole phonon of the low-lying {Delta}l={Delta}j=3 proton- and neutron in-shell 3{sup -} excitations which are of vital significance for the octupole mode in open-shell nuclei. (author). 17 refs., 2 figs.

  16. Enhancement of spin-lattice coupling in nanoengineered oxide films and heterostructures by laser MBE

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Xiaoxing [Temple Univ., Philidelphia, PA (United States)

    2017-06-08

    The objective of the proposed research is to investigate nanoengineered oxide films and multilayer structures that are predicted to show desirable properties. The main focus of the project is an atomic layer-by-layer laser MBE (ALL-Laser MBE ) technique that is superior to the conventional laser MBE in broadening the conditions for the synthesis of high quality nanoscale oxides and new designer materials. In ALL-Laser MBE, separate oxide targets are used instead of one compound target in the conventional laser MBE. The targets are switched back and forth in front of a UV laser beam as they are alternately ablated. The oxide film is thus constructed one atomic layer at a time. The growth of each atomic layer is monitored and controlled by the reflection high energy electron diffraction (RHEED). The intensity of the diffraction spots increases or decreases depending on the chemistry of each atomic layer as well as the surface roughness. This allows us to determine whether the chemical ratio of the different elements in the films meets the desired value and whether each atomic layer is complete. ALL-Laser MBE is versatile: it works for non-polar film on non-polar substrate, polar film on polar substrate, and polar film on non-polar substrate. (In a polar material, each atomic layer is charged whereas in a non-polar material the atomic layers are charge neutral.) It allows one to push the thermodynamic boundary further in stabilizing new phases than reactive MBE and PLD, two of the most successful techniques for oxide thin films. For example, La5Ni4O13, the Ruddlesden-Popper phase with n = 4, has never been reported in the literature because it needs atomic layer-by-layer growth at high oxygen pressures, not possible with other growth techniques. ALL-Laser MBE makes it possible. We have studied the interfacial 2-dimensional electron gas in the LaAlO3/SrTiO3 system, whose mechanism has been a subject of controversy. According to the most prevailing electronic reconstruction mechanism, a positive diverging electric potential is built up in the polar LaAlO3 film when it is grown on a TiO2-terminated SrTiO3 substrate, which is non-polar. This leads to the transfer of half of an electron from the LaAlO3 film surface to SrTiO3 when the LaAlO3 layer is thicker than 4 unit cells, creating a 2D electron gas at the interface with a sheet carrier density of 3.3×1014/cm2 for sufficiently thick LaAlO3. A serious inconsistency with this mechanism is that the carrier densities reported experimentally are invariably lower than the expected value. The most likely reason is that the SrTiO3 substrate is oxygen difficient due to the low oxygen pressures (< 10 mTorr) during growth, and post-growth annealing in oxygen is often used to remove the oxygen vacancies. People cannot grow the LaAlO3 film in higher oxygen pressures - it results in insulating samples or 3D island growth. Because we grow the LaAlO3 film one atomic layer at a time, we were able to grow conducting LaAlO3/SrTiO3 interfaces at a high oxygen pressure with ALL-Laser MBE, as high as 37 mTorr. The high oxygen pressure helps to prevent the possible oxygen reduction in SrTiO3, ensure that the LaAlO3 films are sufficiently oxygenated. Measurements of x-ray linear dichroism (XLD) and x-ray magnetic circular dichroism (XMCD) both show that the spectra of our films are similar to those of well oxygenated samples. In the LaAlO3/SrTiO3 interfaces grown by ALL-Laser MBE at 37 mTorr oxygen pressure, a quantitative agreement between our experimental result and the theoretical prediction was observed, which provides a strong support to the electronic reconstruction mechanism. The key differences between our result and the previous reports are the high oxygen pressure during the film growth and the high film crystallinity. The high oxygen pressure suppresses the likelihood of oxygen vacancies in SrTiO3. Well oxygenated samples produced during film growth can avoid possible defects when sufficient oxygen is provided only after the growth by annealing. Using ALL-Laser MBE, we also synthesized high-quality singlec-rystalline CaMnO3 films. The systematic increase of the oxygen vacancy content in CaMnO3 as a function of applied in-plane strain is observed and confirmed experimentally using high-resolution soft x-ray XAS and hard x-ray photoemission spectroscopy (HAXPES). The relevant defect states in the densities of states are identified and the vacancy content in the films quantified using the combination of first-principles theory and core-hole multiplet calculations with holistic fitting. The strain-induced oxygen-vacancy formation and ordering are a promising avenue for designing and controlling new functionalities in complex transition-metal oxides.

  17. Nuclear spin-lattice relaxation of Cu-62 at low temperatures in iron

    Czech Academy of Sciences Publication Activity Database

    Golovko, V. V.; Kraev, I. S.; Phalet, T.; Severijns, N.; Vénos, Drahoslav; Zákoucký, Dalibor; Herzog, P.; Tramm, C.; Köster, U.; Srnka, D.; Honusek, Milan; Delaure, B.; Beck, M.; Kozlov, V. Y.; Lindroth, A.

    2006-01-01

    Roč. 74, č. 4 (2006), 044313-1-044313-5 ISSN 0556-2813 Institutional research plan: CEZ:AV0Z10480505 Keywords : orientatione xperiments * HPGE detectors * online Subject RIV: BE - Theoretical Physics Impact factor: 3.327, year: 2006

  18. The complexity of translationally invariant low-dimensional spin lattices in 3D

    Science.gov (United States)

    Bausch, Johannes; Piddock, Stephen

    2017-11-01

    In this theoretical paper, we consider spin systems in three spatial dimensions and consider the computational complexity of estimating the ground state energy, known as the local Hamiltonian problem, for translationally invariant Hamiltonians. We prove that the local Hamiltonian problem for 3D lattices with face-centered cubic unit cells and 4-local translationally invariant interactions between spin-3/2 particles and open boundary conditions is QMAEXP-complete, where QMAEXP is the class of problems which can be verified in exponential time on a quantum computer. We go beyond a mere embedding of past hard 1D history state constructions, for which the local spin dimension is enormous: even state-of-the-art constructions have local dimension 42. We avoid such a large local dimension by combining some different techniques in a novel way. For the verifier circuit which we embed into the ground space of the local Hamiltonian, we utilize a recently developed computational model, called a quantum ring machine, which is especially well suited for translationally invariant history state constructions. This is encoded with a new and particularly simple universal gate set, which consists of a single 2-qubit gate applied only to nearest-neighbour qubits. The Hamiltonian construction involves a classical Wang tiling problem as a binary counter which translates one cube side length into a binary description for the encoded verifier input and a carefully engineered history state construction that implements the ring machine on the cubic lattice faces. These novel techniques allow us to significantly lower the local spin dimension, surpassing the best translationally invariant result to date by two orders of magnitude (in the number of degrees of freedom per coupling). This brings our models on par with the best non-translationally invariant construction.

  19. Nuclear spin-lattice relaxation in n -type insulating and metallic GaAs single crystals

    Science.gov (United States)

    Lu, J.; Hoch, M. J. R.; Kuhns, P. L.; Moulton, W. G.; Gan, Z.; Reyes, A. P.

    2006-09-01

    The coupling of electron and nuclear spins in n-GaAs changes significantly as the donor concentration n increases through the insulator-metal critical concentration nC˜1.2×1016cm-3 . The present measurements of the Ga71 relaxation rates W made as a function of magnetic field (1-13T) and temperature (1.5-300K) for semi-insulating GaAs and for three doped n-GaAs samples with donor concentrations n=5.9×1015 , 7×1016 , and 2×1018cm-3 , show marked changes in the relaxation behavior with n . Korringa-like relaxation is found in both metallic samples for T30K phonon-induced nuclear quadrupolar relaxation is dominant. The relaxation rate measurements permit determination of the electron probability density at Ga71 sites. A small Knight shift of -3.3ppm was measured on the most metallic (2×1018cm-3) sample using magic-angle spinning at room temperature. For the n=5.9×1015cm-3 sample, a nuclear relaxation model involving the Fermi contact hyperfine interaction, rapid spin diffusion, and exchange coupled local moments is proposed. While the relaxation rate behavior with temperature for the weakly metallic sample, n=7×1016cm-3 , is similar to that found for the just-insulating sample, the magnetic field dependence is quite different. For the 5.9×1015cm-3 sample, increasing the magnetic field leads to a decrease in the relaxation rate, while for the 7×1016cm-3 sample this results in an increase in the relaxation rate ascribed to an increase in the density of states at the Fermi level as the Landau level degeneracy is increased.

  20. Carbon-13 spin lattice relaxation and photoelectron spectroscopy of some aromatic sulphides and sulphones

    International Nuclear Information System (INIS)

    Mellink, W.A.

    1978-01-01

    Carbon-13 NMR spectroscopy and photoelectron spectroscopy have been used to study the electronic structure of symmetric dithienothiophenes and corresponding sulphones. The physical data obtained from both spectroscopic techniques have been interpreted with the aid of quantum mechanical calculations. (Auth.)

  1. Temperature dependence of the NMR spin-lattice relaxation rate for spin-1/2 chains

    Science.gov (United States)

    Coira, E.; Barmettler, P.; Giamarchi, T.; Kollath, C.

    2016-10-01

    We use recent developments in the framework of a time-dependent matrix product state method to compute the nuclear magnetic resonance relaxation rate 1 /T1 for spin-1/2 chains under magnetic field and for different Hamiltonians (XXX, XXZ, isotropically dimerized). We compute numerically the temperature dependence of the 1 /T1 . We consider both gapped and gapless phases, and also the proximity of quantum critical points. At temperatures much lower than the typical exchange energy scale, our results are in excellent agreement with analytical results, such as the ones derived from the Tomonaga-Luttinger liquid (TLL) theory and bosonization, which are valid in this regime. We also cover the regime for which the temperature T is comparable to the exchange coupling. In this case analytical theories are not appropriate, but this regime is relevant for various new compounds with exchange couplings in the range of tens of Kelvin. For the gapped phases, either the fully polarized phase for spin chains or the low-magnetic-field phase for the dimerized systems, we find an exponential decrease in Δ /(kBT ) of the relaxation time and can compute the gap Δ . Close to the quantum critical point our results are in good agreement with the scaling behavior based on the existence of free excitations.

  2. The second RPA description for the decay of the one-phonon nuclear collective states at finite temperature

    International Nuclear Information System (INIS)

    Yannouleas, C.; Jang, S.

    1986-01-01

    The zero-temperature second RPA is generalized to finite temperatures through the use of the method of linearization of the equations of motion. After elimination of the quadruples, for low enough temperatures and within the subspace spanned by the doubles, a proper symmetrization yields an eigenvalue equation which exhibits formal properties like the simple RPA. From this second RPA eigenvalue equation, a closed formula for the spreading width of an isolated collective state is extracted. The second RPA can be recast in the form of a generalized collision term and be compared with the method of the Bethe-Salpeter equation for the two-body Green function. However, the second RPA method (and results) contrasts with the approach (and corresponding results) of the Boltzmann collision term, which is usually viewed as the appropriate agent for nuclear dissipation. (orig.)

  3. Direct Democracy

    DEFF Research Database (Denmark)

    Beramendi, Virginia; Ellis, Andrew; Kaufman, Bruno

    While many books on direct democracy have a regional or national approach, or simply focus on one of the many mechanisms associated with direct democracy, this Handbook delves into a global comparison of direct democracy mechanisms, including referendums, citizens' initiatives, agenda initiatives...... learned. In addition, the uniquely comprehensive world survey outlines direct democracy provisions in 214 countries and territories and indicates which, if any, of these provisions are used by each country or territory at both the national and sub-national levels. Furthermore, the world survey includes...

  4. Directing 101.

    Science.gov (United States)

    Pintoff, Ernest

    Providing an introduction to anyone considering directing as a field of study or career, this book takes a broad look at the process of directing and encourages students and professionals alike to look outside of the movie industry for inspiration. Chapters in the book discuss selecting and acquiring material; budgeting and financing; casting and…

  5. Microscopic description of elastic and direct inelastic nucleon scattering off spherical nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Dupuis, M. [CEA, DAM, DIF, Arpajon (France)

    2017-05-15

    The purpose of this study is to improve the modeling of nucleon direct inelastic scattering to the continuum using a microscopic and parameter-free approach. For the first time, direct elastic scattering, inelastic scattering to discrete excitations and to the continuum are described within a microscopic approach without adjustable parameters. Proton scattering off {sup 90}Zr and {sup 208}Pb are the reactions used as test case examples of the calculations. The model uses the Melbourne g-matrix and the Random Phase Approximation description of nuclear states, implemented with the Gogny D1S interaction. The relevant optical and transition potentials in a finite nucleus are calculated within a local density approximation. As we use the nuclear matter approach we limit our study to incident energies above 40 MeV. We first checked that this model provides an accurate account of measured cross sections for elastic scattering and inelastic scattering to discrete states. It is then applied to the direct inelastic scattering to the continuum considering all one-phonon excitations predicted within the RPA approach. This accounts for a part of the direct pre-equilibrium emission, often labeled as the one-step direct process in quantum-based approaches. Our approach provides a very accurate description of angular distributions where the one-step process dominates. The impact of collective excitations is shown to be non negligible for energy transfer to the target up to 20 MeV, decreasing as the incident energy increases. For incident energies above 80 MeV, our modeling provides a good account of direct proton emission for an energy transfer to the target up to 30 MeV. However, the proton emission we predict underestimates the measured cross sections for incident energies below 80 MeV. We compare our prediction to those of the phenomenological exciton model to help interpret this result. Directions that may improve our modeling are discussed. (orig.)

  6. Microscopic description of elastic and direct inelastic nucleon scattering off spherical nuclei

    Science.gov (United States)

    Dupuis, M.

    2017-05-01

    The purpose of this study is to improve the modeling of nucleon direct inelastic scattering to the continuum using a microscopic and parameter-free approach. For the first time, direct elastic scattering, inelastic scattering to discrete excitations and to the continuum are described within a microscopic approach without adjustable parameters. Proton scattering off 90Zr and 208Pb are the reactions used as test case examples of the calculations. The model uses the Melbourne g-matrix and the Random Phase Approximation description of nuclear states, implemented with the Gogny D1S interaction. The relevant optical and transition potentials in a finite nucleus are calculated within a local density approximation. As we use the nuclear matter approach we limit our study to incident energies above 40 MeV. We first checked that this model provides an accurate account of measured cross sections for elastic scattering and inelastic scattering to discrete states. It is then applied to the direct inelastic scattering to the continuum considering all one-phonon excitations predicted within the RPA approach. This accounts for a part of the direct pre-equilibrium emission, often labeled as the one-step direct process in quantum-based approaches. Our approach provides a very accurate description of angular distributions where the one-step process dominates. The impact of collective excitations is shown to be non negligible for energy transfer to the target up to 20 MeV, decreasing as the incident energy increases. For incident energies above 80 MeV, our modeling provides a good account of direct proton emission for an energy transfer to the target up to 30 MeV. However, the proton emission we predict underestimates the measured cross sections for incident energies below 80 MeV. We compare our prediction to those of the phenomenological exciton model to help interpret this result. Directions that may improve our modeling are discussed.

  7. Magnetism, spin-lattice-orbital coupling and exchange-correlation energy in oxide heterostructures: Nickelate, titanate, and ruthenate

    Science.gov (United States)

    Han, Myung-Joon

    Many interesting physical phenomena and material characteristics in transition-metal oxides (TMO) come out of the intriguing interplay between charge, spin, orbital, and lattice degrees of freedom. In the thin film and/or heterointerface form of TMO, this feature can be controlled and thus be utilized. Simultaneously, however, its detailed characteristic is more difficult to be identified experimentally. For this reason, the first-principles-based approach has been playing an important role in this field of research. In this talk, I will try to give an overview of current status of first-principles methodologies especially for the magnetism in the correlated oxide heterostructures or thin films. Nickelate, titanate, and ruthenate will be taken as representative examples to demonstrate the powerfulness of and the challenges to the current methodologies On the one hand, first-principles calculation provides the useful information, understanding and prediction which can hardly be obtained from other theoretical and experimental techniques. Nickelate-manganite superlattices (LaNiO3/LaMnO3 and LaNiO3/CaMnO3) are taken as examples. In this interface, the charge transfer can induce the ferromagnetism and it can be controlled by changing the stacking sequence and number of layers. The exchange-correlation (XC) functional dependence seems to give only quantitatively different answers in this case. On the other hand, for the other issues such as orbital polarization/order coupled with spin order, the limitation of current methodology can be critical. This point will be discussed with the case of tatinate superlattice (LaTiO3/LaAlO3) . For ruthenates (SrRuO3\\ and Sr2RuO4) , we found that the probably more fundamental issue could be involved. The unusually strong dependence on the XC functional parametrization is found to give a qualitatively different conclusion for the experimentally relevant parameter regions. This work was supported by National Research Foundation of Korea (2014R1A1A2057202).

  8. Novel spin dynamics in ferrimagnetic molecular chains from 1H NMR and μSR spin-lattice relaxation measurements

    International Nuclear Information System (INIS)

    Micotti, E.; Lascialfari, A.; Rigamonti, A.; Aldrovandi, S.; Caneschi, A.; Gatteschi, D.; Bogani, L.

    2004-01-01

    The spin dynamics in the helical chain Co(hfac) 2 NITPhOMe has been investigated by 1 H NMR and μSR relaxation. In the temperature range 15< T<60 K, the results are consistent with the relaxation of the homogeneous magnetization. For T≤15 K, NMR and μSR evidence a second spin relaxation mechanism, undetected by the magnetization measurements. From the analysis of these data, insights on this novel relaxation process are derived

  9. Proton spin-lattice relaxation in a liquid crystal-Aerosil complex above the bulk isotropization temperature

    Energy Technology Data Exchange (ETDEWEB)

    Anoardo, E.; Grinberg, F.; Vilfan, M.; Kimmich, R

    2004-02-16

    We present a study of the molecular dynamics in an octylcyanobiphenyl (8CB)-Aerosil complex above the bulk isotropization temperature. Using proton nuclear magnetic relaxation experiments in the laboratory frame (T{sub 1}{sup -1}) and in the rotating-frame (T{sub 1{rho}}{sup -1}), we found a notable increase of the relaxation rates in the kHz frequency range as compared to the bulk 8CB liquid crystal at the same temperature. The field-cycling technique was used for the laboratory frame experiments while a conventional apparatus was used for the rotating frame method. The observed behavior is analyzed with the aid of Monte Carlo simulations on the basis of a two-phase fast-exchange model distinguishing surface-ordered and bulk phases. Two processes affecting the low frequency relaxation could be identified: reorientation mediated by translational displacements, accounting for molecular reorientations, and exchange losses of molecules from the surface to the bulk.

  10. Novel spin dynamics in ferrimagnetic molecular chains from 1H NMR and μSR spin-lattice relaxation measurements

    Science.gov (United States)

    Micotti, E.; Lascialfari, A.; Rigamonti, A.; Aldrovandi, S.; Caneschi, A.; Gatteschi, D.; Bogani, L.

    2004-05-01

    The spin dynamics in the helical chain Co(hfac) 2NITPhOMe has been investigated by 1H NMR and μSR relaxation. In the temperature range 15

  11. Spontaneous structural distortion of the metallic Shastry-Sutherland system Dy B4 by quadrupole-spin-lattice coupling

    Science.gov (United States)

    Sim, Hasung; Lee, Seongsu; Hong, Kun-Pyo; Jeong, Jaehong; Zhang, J. R.; Kamiyama, T.; Adroja, D. T.; Murray, C. A.; Thompson, S. P.; Iga, F.; Ji, S.; Khomskii, D.; Park, Je-Geun

    2016-11-01

    Dy B4 has a two-dimensional Shastry-Sutherland (Sh-S) lattice with strong Ising character of the Dy ions. Despite the intrinsic frustrations, it undergoes two successive transitions: a magnetic ordering at TN=20 K and a quadrupole ordering at TQ=12.5 K . From high-resolution neutron and synchrotron x-ray powder diffraction studies, we have obtained full structural information on this material in all phases and demonstrate that structural modifications occurring at quadrupolar transition lead to the lifting of frustrations inherent in the Sh-S model. Our paper thus provides a complete experimental picture of how the intrinsic frustration of the Sh-S lattice can be lifted by the coupling to quadrupole moments. We show that two other factors, i.e., strong spin-orbit coupling and long-range Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in metallic Dy B4 , play an important role in this behavior.

  12. Directing Creativity

    DEFF Research Database (Denmark)

    Darsø, Lotte; Ibbotson, Piers

    2008-01-01

    In this article we argue that leaders facing complex challenges can learn from the arts, specifically that leaders can learn by examining how theatre directors direct creativity through creative constraints. We suggest that perceiving creativity as a boundary phenomenon is helpful for directing it....... Like leaders, who are caught in paradoxical situations where they have to manage production and logistics simultaneously with making space for creativity and innovation, theatre directors need to find the delicate balance between on one hand renewal of perceptions, acting and interaction...... and on the other hand getting ready for the opening night. We conclude that the art of directing creativity is linked to developing competencies of conscious presence, attention and vigilance, whereas the craft of directing creativity concerns communication, framing and choice....

  13. Direct Heat

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P J

    1990-01-01

    Potential resources and applications of earth heat in the form of geothermal energy are large. United States direct uses amount to 2,100 MWt thermal and worldwide 8,850 MWt above a reference temperature of 35 degrees Celsius. Space and district heating are the major direct uses of geothermal energy. Equipment employed in direct use projects is of standard manufacture and includes downhole and circulation pumps, transmission and distribution pipelines, heat exchangers and convectors, heat pumps and chillers. Direct uses of earth heat discussed are space and district heating, greenhouse heating and fish farming, process and industrial applications. The economic feasibility of direct use projects is governed by site specific factors such as location of user and resource, resource quality, system load factor and load density, as well as financing. Examples are presented of district heating in Klamath Falls, and Elko. Further developments of direct uses of geothermal energy will depend on matching user needs to the resource, and improving load factors and load density.

  14. Directed polymers versus directed percolation

    Science.gov (United States)

    Halpin-Healy, Timothy

    1998-10-01

    Universality plays a central role within the rubric of modern statistical mechanics, wherein an insightful continuum formulation rises above irrelevant microscopic details, capturing essential scaling behaviors. Nevertheless, occasions do arise where the lattice or another discrete aspect can constitute a formidable legacy. Directed polymers in random media, along with its close sibling, directed percolation, provide an intriguing case in point. Indeed, the deep blood relation between these two models may have sabotaged past efforts to fully characterize the Kardar-Parisi-Zhang universality class, to which the directed polymer belongs.

  15. Direct marketing

    Directory of Open Access Journals (Sweden)

    Čičić Muris

    2002-01-01

    Full Text Available Direct Marketing (DM is usually treated as unworthy activity, with actions at the edge of legality and activities minded cheating. Despite obvious problems regarding ethics and privacy threat, DM with its size, importance and role in a concept of integrated marketing communication deserves respect and sufficient analysis and review

  16. Direct Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Austern, N. [University of Pittsburgh, Pittsburgh, PA (United States)

    1963-01-15

    In order to give a unified presentation of one point of view, these lectures are devoted only to a detailed development of the standard theories of direct reactions, starting from basic principles. Discussion is given of the present status of the theories, of the techniques used for practical calculation, and of possible future developments. The direct interaction (DI) aspects of a reaction are those which involve only a few of the many degrees of freedom of a nucleus. In fact the minimum number of degrees of freedom which must be involved in a reaction are those required to describe the initial and final channels, and DI studies typically consider these degrees of freedom and no others. Because of this simplicity DI theories may be worked out in painstaking detail. DI processes concern only part of the wave function for a problem. The other part involves complicated excitations of many degrees of freedom, and gives the compound nucleus (CN) effects. While it is extremely interesting to learn how to separate DI and CN effects in an orderly manner, if they are both present in a reaction, no suitable method has yet been found. Instead, current work stresses the kinds of reactions and the kinds of final states in which DI effects dominate and in which CN effects may almost be forgotten. The DI cross-sections which are studied are often extremely large, comparable to elastic scattering cross-sections. (author)

  17. Future direction of direct writing

    Science.gov (United States)

    Kim, Nam-Soo; Han, Kenneth N.

    2010-11-01

    Direct write technology using special inks consisting of finely dispersed metal nanoparticles in liquid is receiving an undivided attention in recent years for its wide range of applicability in modern electronic industry. The application of this technology covers radio frequency identification-tag (RFID-tag), flexible-electronics, organic light emitting diodes (OLED) display, e-paper, antenna, bumpers used in flip-chip, underfilling, frit, miniresistance applications and biological uses, artificial dental applications and many more. In this paper, the authors have reviewed various direct write technologies on the market and discussed their advantages and shortfalls. Emphasis has given on microdispensing deposition write (MDDW), maskless mesoscale materials deposition (M3D), and ink-jet technologies. All of these technologies allow printing various patterns without employing a mask or a resist with an enhanced speed with the aid of computer. MDDW and M3D are capable of drawing patterns in three-dimension and MDDW, in particular, is capable of writing nanoinks with high viscosity. However, it is still far away for direct write to be fully implemented in the commercial arena. One of the hurdles to overcome is in manufacturing conductive inks which are chemically and physically stable, capable of drawing patterns with acceptable conductivity, and also capable of drawing patterns with acceptable adhesiveness with the substrates. The authors have briefly discussed problems involved in manufacturing nanometal inks to be used in various writing devices. There are numerous factors to be considered in manufacturing such inks. They are reducing agents, concentrations, oxidation, compact ability allowing good conductivity, and stability in suspension.

  18. The spin relaxation of nitrogen donors in 6H SiC crystals as studied by the electron spin echo method

    Science.gov (United States)

    Savchenko, D.; Shanina, B.; Kalabukhova, E.; Pöppl, A.; Lančok, J.; Mokhov, E.

    2016-04-01

    We present the detailed study of the spin kinetics of the nitrogen (N) donor electrons in 6H SiC wafers grown by the Lely method and by the sublimation "sandwich method" (SSM) with a donor concentration of about 1017 cm-3 at T = 10-40 K. The donor electrons of the N donors substituting quasi-cubic "k1" and "k2" sites (Nk1,k2) in both types of the samples revealed the similar temperature dependence of the spin-lattice relaxation rate (T1-1), which was described by the direct one-phonon and two-phonon processes induced by the acoustic phonons proportional to T and to T9, respectively. The character of the temperature dependence of the T1-1 for the donor electrons of N substituting hexagonal ("h") site (Nh) in both types of 6H SiC samples indicates that the donor electrons relax through the fast-relaxing centers by means of the cross-relaxation process. The observed enhancement of the phase memory relaxation rate (Tm-1) with the temperature increase for the Nh donors in both types of the samples, as well as for the Nk1,k2 donors in Lely grown 6H SiC, was explained by the growth of the free electron concentration with the temperature increase and their exchange scattering at the N donor centers. The observed significant shortening of the phase memory relaxation time Tm for the Nk1,k2 donors in the SSM grown sample with the temperature lowering is caused by hopping motion of the electrons between the occupied and unoccupied states of the N donors at Nh and Nk1,k2 sites. The impact of the N donor pairs, triads, distant donor pairs formed in n-type 6H SiC wafers on the spin relaxation times was discussed.

  19. Novel spin dynamics in ferrimagnetic molecular chains from {sup 1}H NMR and {mu}SR spin-lattice relaxation measurements

    Energy Technology Data Exchange (ETDEWEB)

    Micotti, E. E-mail: micotti@fisicavolta.unipv.it; Lascialfari, A.; Rigamonti, A.; Aldrovandi, S.; Caneschi, A.; Gatteschi, D.; Bogani, L

    2004-05-01

    The spin dynamics in the helical chain Co(hfac){sub 2}NITPhOMe has been investigated by {sup 1}H NMR and {mu}SR relaxation. In the temperature range 15

  20. Minimization of spin-lattice relaxation time with highly viscous solvents for acquisition of natural abundance nitrogen-15 and silicon-29 nuclear magnetic resonance spectra

    International Nuclear Information System (INIS)

    Bammel, B.P.; Evilia, R.F.

    1982-01-01

    The use of high viscosity solution conditions to decrease T 1 of 15 N and 29 Si nuclei so that natural abundance NMR spectra can be acquired in reasonable times is illustrated. Significant T 1 decreases with negligible increases in peak width are observed. No spectral shifts are observed in any of the cases studied. Highly viscous solutions are produced by using glycerol as a solvent for water-soluble molecules and a mixed solvent consisting of toluene saturated with polystyrene for organic-soluble molecules. The microviscosity in the latter solvent is found to be much less than the observed macroviscosity. Hydrogen bonding of glycerol to the NH 2 of 2-aminopyridine results in a greater than predicted decrease in T 1 for this nitrogen. The technique appears to be a useful alternative to paramagnetic relaxation reagents

  1. A general model to calculate the spin-lattice (T1) relaxation time of blood, accounting for haematocrit, oxygen saturation and magnetic field strength.

    Science.gov (United States)

    Hales, Patrick W; Kirkham, Fenella J; Clark, Christopher A

    2016-02-01

    Many MRI techniques require prior knowledge of the T1-relaxation time of blood (T1bl). An assumed/fixed value is often used; however, T1bl is sensitive to magnetic field (B0), haematocrit (Hct), and oxygen saturation (Y). We aimed to combine data from previous in vitro measurements into a mathematical model, to estimate T1bl as a function of B0, Hct, and Y. The model was shown to predict T1bl from in vivo studies with a good accuracy (± 87 ms). This model allows for improved estimation of T1bl between 1.5-7.0 T while accounting for variations in Hct and Y, leading to improved accuracy of MRI-derived perfusion measurements. © The Author(s) 2015.

  2. Attenuation of nuclear orientation of .sup.127./sup.In in GD and the InGDKorringa spin-lattice relaxation time constant

    Czech Academy of Sciences Publication Activity Database

    Stone, J.; Ohya, S.; Rikovska, J.; Woehr, A.; Betts, P.; Dupák, Jan; Fogelberg, B.; Jacobsson, L.

    č. 133 (2001), s. 111 - 115 ISSN 0304-3843 Institutional research plan: CEZ:AV0Z2065902 Keywords : nuclear orientation * Korringa constant Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.634, year: 2001

  3. Direct selling particularities

    OpenAIRE

    Greifová, Daniela

    2009-01-01

    Bachelor thesis is focused on the parcularities of direct selling, self regulation of this industry, multi-level marketing which is the most used sales method in the field of direct selling. The part of the thesis is dedicated to the issue of customer psychology that is very important for achieving success in direct selling. Main goals are to provide readers with the general view of direct selling and analysis of growing possibilities of the industry in the future.

  4. Directed Energy Weapons

    Science.gov (United States)

    2007-12-01

    future business . In defense systems, the key to future business is the existence of funded programs. Military commanders understand the lethality and...directed energp capabilities that can provide visibiliy into the likey futur business case for sustaining directed energy industry capabilities...the USD (I) staff to be afocalpointfor advocating improvement in all dimensions of directed energy intelligence. - The Director, Defense Inteligence

  5. Cross relaxation in nitroxide spin labels

    DEFF Research Database (Denmark)

    Marsh, Derek

    2016-01-01

    Cross relaxation, and mI-dependence of the intrinsic electron spin-lattice relaxation rate We, are incorporated explicitly into the rate equations for the electron-spin population differences that govern the saturation behaviour of 14N- and 15N-nitroxide spin labels. Both prove important in spin......-label EPR and ELDOR, particularly for saturation recovery studies. Neither for saturation recovery, nor for CW-saturation EPR and CW-ELDOR, can cross relaxation be described simply by increasing the value of We, the intrinsic spin-lattice relaxation rate. Independence of the saturation recovery rates from...... the hyperfine line pumped or observed follows directly from solution of the rate equations including cross relaxation, even when the intrinsic spin-lattice relaxation rate We is mI-dependent....

  6. NMR studies of spin dynamics in cuprates

    International Nuclear Information System (INIS)

    Takigawa, M.; Mitzi, D.B.

    1994-01-01

    The authors report recent NMR results in cuprates. The oxygen Knight shift and the Cu nuclear spin-lattice relaxation rate in Bi 2.1 Sr 1.94 Ca 0.88 Cu 2.07 O 8+σ single crystals revealed a gapless superconducting state, which can be most naturally explained by a d-wave pairing state and the intrinsic disorder in this material. The Cu nuclear spin-spin relaxation rate in underdoped YBa 2 Cu 3 O 6.63 shows distinct temperature dependence from the spin-lattice relaxation rate, providing direct evidence for a pseudo spin-gap near the antiferromagnetic wave vector

  7. NMR studies of spin dynamics in cuprates

    Science.gov (United States)

    Takigawa, M.; Mitzi, D. B.

    1994-04-01

    We report recent NMR results in cuprates. The oxygen Knight shift and the Cu nuclear spin-lattice relaxation rate in Bi2.1Sr1.94Ca0.88Cu2.07O8+δ single crystals revealed a gapless superconducting state, which can be most naturally explained by a d-wave pairing state and the intrinsic disorder in this material. The Cu nuclear spin-spin relaxation rate in underdoped YBa2Cu3O6.63 shows distinct temperature dependence from the spin-lattice relaxation rate, providing direct evidence for a pseudo spin-gap near the antiferromagnetic wave vector.

  8. Directed Energy Anechoic Chamber

    Data.gov (United States)

    Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

  9. Records Management Directive

    Data.gov (United States)

    Office of Personnel Management — The Office of Personnel Management (OPM) Records Management Directive provides guidelines for the management of OPM records, and identifies the records management...

  10. Direct observation of magnon-phonon coupling in yttrium iron garnet

    Science.gov (United States)

    Man, Haoran; Shi, Zhong; Xu, Guangyong; Xu, Yadong; Chen, Xi; Sullivan, Sean; Zhou, Jianshi; Xia, Ke; Shi, Jing; Dai, Pengcheng

    2017-09-01

    The magnetic insulator yttrium iron garnet (YIG) with a ferrimagnetic transition temperature of ˜560 K has been widely used in microwave and spintronic devices. Anomalous features in spin Seeback effect (SSE) voltages have been observed in Pt/YIG and attributed to magnon-phonon coupling. Here, we use inelastic neutron scattering to map out low-energy spin waves and acoustic phonons of YIG at 100 K as a function of increasing magnetic field. By comparing the zero and 9.1 T data, we find that instead of splitting and opening up gaps at the spin wave and acoustic phonon dispersion intersecting points, magnon-phonon coupling in YIG enhances the hybridized scattering intensity. These results are different from expectations of conventional spin-lattice coupling, calling for different paradigms to understand the scattering process of magnon-phonon interactions and the resulting magnon polarons.

  11. Direct Conversion of Energy.

    Science.gov (United States)

    Corliss, William R.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Direct energy conversion involves energy transformation without moving parts. The concepts of direct and dynamic energy conversion plus the laws governing energy conversion are investigated. Among the topics…

  12. Decisions Concerning Directional Dependence

    Science.gov (United States)

    von Eye, Alexander; DeShon, Richard P.

    2012-01-01

    In this rejoinder, von Eye and DeShon discuss the decision strategies proposed in their original article ("Directional Dependence in Developmental Research," this issue), as well as the ones proposed by the authors of the commentary (Pornprasertmanit and Little, "Determining Directional Dependency in Causal Associations," this issue). In addition,…

  13. Directionality of dog vocalizations

    Science.gov (United States)

    Frommolt, Karl-Heinz; Gebler, Alban

    2004-07-01

    The directionality patterns of sound emission in domestic dogs were measured in an anechoic environment using a microphone array. Mainly long-distance signals from four dogs were investigated. The radiation pattern of the signals differed clearly from an omnidirectional one with average differences in sound-pressure level between the frontal and rear position of 3-7 dB depending from the individual. Frequency dependence of directionality was shown for the range from 250 to 3200 Hz. The results indicate that when studying acoustic communication in mammals, more attention should be paid to the directionality pattern of sound emission.

  14. FAA Directives System

    Science.gov (United States)

    1992-08-26

    Consistent with the Federal Aviation Administration's mission to foster a safe, : secure, and efficient aviation system is the need for an effective and efficient : process for communitcating policy and procedures. The FAA Directives System : provide...

  15. Assessing directionality in context

    African Journals Online (AJOL)

    Kate H

    In support of first-language interpreting as the exclusive interpreting direction, ... some light on the possible interaction between two independent variables, .... the “local context” refers to the setting, genre, participants, and aims of the event.

  16. Directed line liquids

    International Nuclear Information System (INIS)

    Kamien, R.D.

    1992-01-01

    This thesis is devoted to the study of ensembles of dense directed lines. These lines are principally to be thought of as polymers, though they also have the morphology of flux lines in high temperature superconductors, strings of colloidal spheres in electrorheological fluids and the world lines of quantum mechanical bosons. The authors discuss how directed polymer melts, string-like formations in electrorheological and ferro-fluids, flux lines in high temperature superconductors and the world lines of quantum mechanical bosons all share similar descriptions. They study a continuous transition in all of these systems, and then study the critical mixing properties of binary mixtures of directed polymers through the renormalization group. They predict the exponents for a directed polymer blend consolute point and a novel two-phase superfluid liquid-gas critical point

  17. The ''energy tax'' directive

    International Nuclear Information System (INIS)

    Anon.

    2003-01-01

    As Austria dropped its reservation, U.E. Economics and Finance Ministers gave, on 20 March at Brussels, their political agreement to the proposed Directive on a Community framework for the taxation of energy products. (author)

  18. Directed GF-spaces

    Directory of Open Access Journals (Sweden)

    F.G. Arenas

    2001-10-01

    Full Text Available In this paper we introduce the concept of directed fractal structure, which is a generalization of the concept of fractal structure (introduced by the authors. We study the relation with transitive quasiuniformities and inverse limits of posets. We define the concept of GF-compactification and apply it to prove that the Stone-Cech compactification can be obtained as the GF-compactification of the directed fractal structure associated to the Pervin quasi-uniformity.

  19. Directed network modules

    International Nuclear Information System (INIS)

    Palla, Gergely; Farkas, Illes J; Pollner, Peter; Derenyi, Imre; Vicsek, Tamas

    2007-01-01

    A search technique locating network modules, i.e. internally densely connected groups of nodes in directed networks is introduced by extending the clique percolation method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos-Renyi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own web-pages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae. The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and Google's web-pages, overlaps are likely to contain in-hubs, whereas the modules in the email and transcriptional regulatory network tend to overlap via out-hubs

  20. Directivity of singers

    Science.gov (United States)

    Jers, Harald

    2005-09-01

    Studies of acoustical balance between singers within a choir by means of room acoustical measurements have shown that the directional sound propagation of the source is important. For this reason the directivity of female and male singers for different vowels has been measured in this investigation. Measurements of a pilot study and some first measurements in 1998 have been supplemented with new measurements and an enhanced setup. A special measurement setup with reference and recording microphones was used to collect the directivity data. A resolution of 10 deg for azimuth and elevation angle was obtained. The results will be shown in 3D spherical plots with frequency adjustments in semitones from 80 to 8000 Hz. The measurements are compared to an artificial singer's directivity, and the influence of a sheet music binder in front of a singer will be shown. The results give information on the directivity of singers and are relevant for the prediction of self-to-other-ratios that result from placement and formation aspects within a choir.

  1. Estimating directional epistasis

    Science.gov (United States)

    Le Rouzic, Arnaud

    2014-01-01

    Epistasis, i.e., the fact that gene effects depend on the genetic background, is a direct consequence of the complexity of genetic architectures. Despite this, most of the models used in evolutionary and quantitative genetics pay scant attention to genetic interactions. For instance, the traditional decomposition of genetic effects models epistasis as noise around the evolutionarily-relevant additive effects. Such an approach is only valid if it is assumed that there is no general pattern among interactions—a highly speculative scenario. Systematic interactions generate directional epistasis, which has major evolutionary consequences. In spite of its importance, directional epistasis is rarely measured or reported by quantitative geneticists, not only because its relevance is generally ignored, but also due to the lack of simple, operational, and accessible methods for its estimation. This paper describes conceptual and statistical tools that can be used to estimate directional epistasis from various kinds of data, including QTL mapping results, phenotype measurements in mutants, and artificial selection responses. As an illustration, I measured directional epistasis from a real-life example. I then discuss the interpretation of the estimates, showing how they can be used to draw meaningful biological inferences. PMID:25071828

  2. Direct reading dosimeter

    International Nuclear Information System (INIS)

    Thomson, I.

    1985-01-01

    This invention is a direct reading dosimeter which is light, small enough to be worn on a person, and measures both dose rates and total dose. It is based on a semiconductor sensor. The gate threshold voltage change rather than absolute value is measured and displayed as a direct reading of the dose rate. This is effected by continuously switching the gate of an MOS transistor from positive to negative bias. The output can directly drive a digital readout or trigger an audible alarm. The sensor device can be a MOSFET, bipolar transistor, or MOSFET capacitor which has its electrical characteristics change due to the trapped charge in the insulating layer of the device

  3. The direction of time

    CERN Document Server

    Reichenbach, Hans

    1999-01-01

    Ever a source of philosophical conjecture and debate, the concept of time represents the beating heart of physics. This final work by the distinguished physicist Hans Reichenbach represents the culmination and integration of a lifetime's philosophical contributions and inquiries into the analysis of time. The result is an outstanding overview of such qualitative, or topological, attributes of time as order and direction.Beginning with a discussion of the emotive significance of time, Reichenbach turns to an examination of the time order of mechanics, the time direction of thermodynamics and m

  4. Incretin secretion: direct mechanisms

    DEFF Research Database (Denmark)

    Balk-Møller, Emilie; Holst, Jens Juul; Kuhre, Rune Ehrenreich

    2014-01-01

    The incretin hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) are secreted from gastro-intestinal K- and L-cells, respectively, and play an important role in post-prandial blood glucose regulation. They do this by direct stimulation of the pancreatic β...... enzyme responsible for incretin degradation (dipeptidyl peptidase-4) is inhibited (drugs are already on the market) while the secretion of endogenous GLP-1 secretion is stimulated at the same time may prove particularly rewarding. In this section we review current knowledge on the mechanisms for direct...

  5. Direct Sulfation of Limestone

    DEFF Research Database (Denmark)

    Hu, Guilin; Dam-Johansen, Kim; Wedel, Stig

    2007-01-01

    The direct sulfation of limestone was studied in a laboratory fixed-bed reactor. It is found that the direct sulfation of limestone involves nucleation and crystal grain growth of the solid product (anhydrite). At 823 K and at low-conversions (less than about 0.5 %), the influences of SO2, O-2...... and CO2 on the direct sulfation of limestone corresponds to apparent reaction orders of about 0.2, 0.2 and -0.5, respectively. Water is observed to promote the sulfation reaction and increase the apparent reaction orders of SO2 and O-2. The influence of O-2 at high O-2 concentrations (> about 15...... %) becomes negligible. In the temperature interval from 723 K to 973 K, an apparent activation energy of about 104 kJ/mol is observed for the direct sulfation of limestone. At low temperatures and low conversions, the sulfation process is most likely under mixed control by chemical reaction and solid...

  6. Danish directional adverbs:

    DEFF Research Database (Denmark)

    Hovmark, Henrik

    2013-01-01

    Danish directional adverbs (DDA) (for instance op ’up’, ned ’down’, and ud ’out’) are characterized by an important special feature as satellites – they have different forms: a zero-form (ud-Ø), a form with a derivative e-suffix (ud-e), and a third form with a prepositional ad-suffix (‘ wards’). ...

  7. Directional loudness perception

    DEFF Research Database (Denmark)

    Sivonen, Ville Pekka

    developed. The research and modeling of loudness have mainly been concerned with the temporal and spectral aspects of sounds, while the spatial aspects have mostly been overlooked. This PhD thesis investigates the spatial aspects of loudness perception, namely, how does the direction from which a sound...

  8. Direct contamination - seasonality

    International Nuclear Information System (INIS)

    Aarkrog, A.

    1994-01-01

    Direct contamination is the primary pathway to terrestrial vegetation in the first period after an activity release to the atmosphere. All radionuclides are able to be transferred via this pathway. Deposition, interception and retention are the three processes involved in direct contamination of crops. Wet deposition is more important than dry deposition in temperature regions. Resuspension and rainsplash both belong to secondary direct deposition and became evident for e.g. radiocaesium after the Chernobyl accident. Seasonality is the varying response to radioactive contamination of crops according to the time of the year when the contamination occurs. Shortlived radionuclides (as 131 I) and those that mainly enter the foodchain by direct contamination (e.g. 137 Cs) are especially important in this connection. In particular, the contamination of cereal crops is influenced by seasonality. As a result of seasonality the impact of the Chernobyl accident on the radioactive contamination of human diet was for the same deposition density higher in southern than in northern Europe. (orig.)

  9. Direct vision internal urethrotomy

    DEFF Research Database (Denmark)

    Jakobsen, H; Willumsen, H; Søndergaard Jensen, L

    1984-01-01

    During a five-year period, direct vision internal urethrotomy was used for the treatment of urethral strictures in 34 men. After the primary operation the patients were followed for an average period of 29 months (range 3-73 months). During this period 53% of the patients were found to have one...

  10. Direct photon experiments

    International Nuclear Information System (INIS)

    Boeggild, H.

    1986-11-01

    The author reviews the experiments on direct photon production in hadronic collisions. After a description of the experimental methods for the study of such processes he presents some results on differential cross sections and the γ/π 0 ratio in π - p, π + p, pp, and anti pp processes as well as in reactions of π - , π + , and p on carbon. (HSI)

  11. Polymer Directed Protein Assemblies

    Directory of Open Access Journals (Sweden)

    Patrick van Rijn

    2013-05-01

    Full Text Available Protein aggregation and protein self-assembly is an important occurrence in natural systems, and is in some form or other dictated by biopolymers. Very obvious influences of biopolymers on protein assemblies are, e.g., virus particles. Viruses are a multi-protein assembly of which the morphology is dictated by poly-nucleotides namely RNA or DNA. This “biopolymer” directs the proteins and imposes limitations on the structure like the length or diameter of the particle. Not only do these bionanoparticles use polymer-directed self-assembly, also processes like amyloid formation are in a way a result of directed protein assembly by partial unfolded/misfolded biopolymers namely, polypeptides. The combination of proteins and synthetic polymers, inspired by the natural processes, are therefore regarded as a highly promising area of research. Directed protein assembly is versatile with respect to the possible interactions which brings together the protein and polymer, e.g., electrostatic, v.d. Waals forces or covalent conjugation, and possible combinations are numerous due to the large amounts of different polymers and proteins available. The protein-polymer interacting behavior and overall morphology is envisioned to aid in clarifying protein-protein interactions and are thought to entail some interesting new functions and properties which will ultimately lead to novel bio-hybrid materials.

  12. Direct Lending Works.

    Science.gov (United States)

    Riley, Richard W.

    1997-01-01

    In its third year, direct lending is working well for college students and administration. It is a simpler, faster, more efficient way of getting loan funds to students that cuts out financial middlemen. It helps students manage their finances better when repaying loans, promotes competition, stimulates program innovation, leads to greater…

  13. Advanced directives: open issues

    Directory of Open Access Journals (Sweden)

    Gabriella Negrini

    2013-05-01

    Full Text Available BACKGROUND In Italy Advanced directives have not been regulated by law yet. Moreover, there is a confusion of concepts: advanced directives, refusal of treatment, medical futility and euthanasia are not synonymous.DISCUSSION The following aspects are then discussed: object of directives; elapse of time between their expression and their application; knowledge of the directives and their obligatory nature. The refusal of a treatment that can save a person’s life is a critical subject. There are different ethical points of view: according to lay ethics, the patient’s self-determination prevails; the religious viewpoint, instead, says that life is a gift which we cannot dispose of. In any case, the patient will be confronted with the professional autonomy of the doctor. Should the doctor save a patient’s life in any case or should he achieve best clinical practice, in respect of his will? The doctor should interpret the patient’s will but with caution and judgment. An exemption from responsibility should be provided by law for doctors who respect patient’s living will.

  14. Direct oxide reducing method

    International Nuclear Information System (INIS)

    Tokiwai, Moriyasu.

    1995-01-01

    Calcium oxides and magnetic oxides as wastes generated upon direct reduction are subjected to molten salt electrolysis, and reduced metallic calcium and magnesium are separated and recovered. Then calcium and magnesium are used recyclically as the reducing agent upon conducting direct oxide reduction. Even calcium oxides and magnesium oxides, which have high melting points and difficult to be melted usually, can be melted in molten salts of mixed fluorides or chlorides by molten-salt electrolysis. Oxides are decomposed by electrolysis, and oxygen is removed in the form of carbon monoxide, while the reduced metallic calcium and magnesium rise above the molten salts on the side of a cathode, and then separated. Since only carbon monoxide is generated as radioactive wastes upon molten salt electrolysis, the amount of radioactive wastes can be greatly reduced, and the amount of the reducing agent used can also be decreased remarkably. (N.H.)

  15. Direct use in Hawaii

    International Nuclear Information System (INIS)

    Beck, A.G.

    1990-01-01

    This paper reports on a public laboratory, Noi'i O Puna, that was established in Hawaii to support direct use research in 1985, tapping the previously unutilized heat in brines from the HGP-A well. Two rounds of small grants were offered to entrepreneurs. With the closure of the HGP-A power plant in late 1989, Noi'i O Puna is expanding its facilities. When the HGP-A well is back in service, Noi'i O Puna will be able to support additional research and development projects, as well as pre-commercial ventures. Direct use industries, which support existing agricultural activities in the region have good potential

  16. Direct Communication Systems

    OpenAIRE

    Krajačić, Ivan

    2016-01-01

    Today we use numerous methods of direct communications, for which we use a technical term Unified Communications. It is almost impossible to imagine the business world today without Unified Communications, which are improving productivity and reducing costs. The goal of using Unified Communications is to ensure a consistent user experience at any location and any device. Skype for Business, a Microsoft product, is one of the solutions for Unified Communications and is described in this thesis...

  17. Directional borehole antenna - Theory

    International Nuclear Information System (INIS)

    Falk, L.

    1992-02-01

    A directional antenna has been developed for the borehole radar constructed during phase 2 of the Stripa project. The new antenna can determine the azimuth of a strong reflector with an accuracy of about 3 degrees as confirmed during experiments in Stripa, although the ratio of borehole diameter to wavelength is small, about 0.03. The antenna synthesizes the effect of a loop antenna rotating in the borehole from four signals measured in turn by a stationary antenna. These signals are also used to calculate an electric dipole signal and a check sum which is used to examine the function of the system. The theory of directional antennas is reviewed and used to design an antenna consisting of four parallel wires. The radiation pattern of this antenna is calculated using transmission line theory with due regard to polarization, which is of fundamental importance for the analysis of directional data. In particular the multipole expansion of the field is calculated to describe the antenna radiation pattern. Various sources of error, e.g. the effect of the borehole, are discussed and the methods of calibrating the antenna are reviewed. The ambiguity inherent in a loop antenna can be removed by taking the phase of the signal into account. Typical reflectors in rock, e.g. fracture zones an tunnels, may be modelled as simple geometrical structures. The corresponding analysis is described and exemplified on measurements from Stripa. Radar data is nowadays usually analyzed directly on the computer screen using the program RADINTER developed within the Stripa project. An algorithm for automatic estimation of the parameters of a reflector have been tested with some success. The relation between measured radar data and external coordinates as determined by rotational indicators is finally expressed in terms of Euler angles. (au)

  18. Direct hydrocarbon fuel cells

    Science.gov (United States)

    Barnett, Scott A.; Lai, Tammy; Liu, Jiang

    2010-05-04

    The direct electrochemical oxidation of hydrocarbons in solid oxide fuel cells, to generate greater power densities at lower temperatures without carbon deposition. The performance obtained is comparable to that of fuel cells used for hydrogen, and is achieved by using novel anode composites at low operating temperatures. Such solid oxide fuel cells, regardless of fuel source or operation, can be configured advantageously using the structural geometries of this invention.

  19. Future directions for QCD

    International Nuclear Information System (INIS)

    Bjorken, J.D.

    1996-10-01

    New directions for exploring QCD at future high-energy colliders are sketched. These include jets within jets. BFKL dynamics, soft and hard diffraction, searches for disoriented chiral condensate, and doing a better job on minimum bias physics. The new experimental opportunities include electron-ion collisions at HERA, a new collider detector at the C0 region of the TeVatron, and the FELIX initiative at the LHC

  20. Perspective on direct conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W B

    1963-10-15

    The objective of direct conversion is high electrical output for minimum total cost, and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment, and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy, and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (auth)

  1. Farm Management: rethinking directions?

    OpenAIRE

    Kemp, David R.; Girdwood, John; Parton, Kevin A.; Charry, Al A.

    2004-01-01

    Farms and farming are major contributors to the world economy, directly responsible for a large part of GDP. These achievements are not trivial and imply that farms are being managed in reasonably effective ways, else agricultural industries would not be sustained. However has the study of Farm Management within Australia made significant contributions to agriculture or lagged in the background. Is it contributing to better Farm Management or merely cataloguing what has happened? Is it leadin...

  2. AngularJS directives

    CERN Document Server

    Vanston, Alex

    2013-01-01

    This book uses a practical, step-by-step approach, starting with how to build directives from the ground up before moving on to creating web applications comprised of multiple modules all working together to provide the best user experience possible.This book is intended for intermediate JavaScript developers who are looking to enhance their understanding of single-page web application development with a focus on AngularJS and the JavaScript MVC frameworks.It is expected that readers will understand basic JavaScript patterns and idioms and can recognize JSON formatted data.

  3. Direct olive oil analysis

    Directory of Open Access Journals (Sweden)

    Peña, F.

    2002-03-01

    Full Text Available The practical impact of “direct analysis” is undeniable as it strong contributes to enhance the so-called productive analytical features such as expeditiousness, reduction of costs and minimisation of risks for the analysts and environment. The main objective is to establish a reliable bypass to the conventional preliminary operations of the analytical process. This paper offers a systematic approach in this context and emphasises the great field of action of direct methodologies in the routine analysis of olive oil. Two main types of methodologies are considered. On the one hand, the direct determination of volatile components is systematically considered. On the other hand, simple procedures to automatically implement the preliminary operations of the oil analysis using simple devices in which the sample is directly introduced with/without a simple dilution are present and discussed.El impacto práctico del análisis directo es tan innegable como que el contribuye decisivamente a mejorar las denominadas características analíticas relacionadas con la productividad como la rapidez, la reducción de costes y la minimización de riesgos para los analistas y el ambiente. El principal objetivo es establecer un adecuado "bypass" a las operaciones convencionales preliminares del proceso analítico. Este artículo ofrece una propuesta sistemática en este contexto y resalta el gran campo de acción de las metodologías directas en los análisis de rutina del aceite de oliva. Se analizan los dos tipos principales de metodologías. Por una lado, se analiza la determinación directa de los compuestos volátiles. Por el otro, se presentan y discuten los procedimientos simples para implementar automáticamente las operaciones preliminares del análisis del aceite usando sistemas simples en los que la muestra se introduce directamente con/sin un dilución simple.

  4. The direct manipulation shell

    International Nuclear Information System (INIS)

    Allen, M.E.; Christiansen, M.

    1992-01-01

    Accelerator controls systems provide parameter display pages which allow the operator to monitor and manipulate selected control points in the system. Display pages are generally implemented as either hand-crafted, purpose-built programs; or by using a specialized display page layout tool. These two methods of display page development exhibit the classic trade-off between functionality vs. ease of implementation. In the Direct Manipulation Shell we approach the process of developing a display page in a manifestly object-oriented manner. This is done by providing a general framework for interactively instantiating and manipulating display objects. (author)

  5. Does direct experience matter?

    DEFF Research Database (Denmark)

    Miralles, Francesc; Giones, Ferran; Gozun, Brian

    2017-01-01

    of being engaged in entrepreneurial behavior on entrepreneurial intention. We aim to shed light on whether the direct experience reinforces an individual’s entrepreneurial intention or reduces it. Building on an extended version of the planned behavior theory, we use the behavioral reasoning theory...... and an individual’s intention by introducing behavioral reasoning theory. These results provide support to initiatives to adapt entrepreneurship promotion efforts to the specific characteristics of the participants.......Entrepreneurial behavior research has used intention models to explain how an individual’s beliefs shape the attitudes and motivations that influence entrepreneurial intention. Nevertheless, as entrepreneurship promotion initiatives become global, it becomes relevant to explore the consequences...

  6. Directions for further research

    DEFF Research Database (Denmark)

    Minsaas, Atle; Psaraftis, Harilaos N.

    2015-01-01

    Green transportation logistics is an area that combines the following: (a) it is relatively new in terms of research carried out thus far, (b) it has become increasingly important for both industry and society, and (c) it is rich in topics for further research, both basic and applied. In this final...... chapter of this book we discuss directions for further research in this area. We do so by taking stock of (1) related recommendations of project SuperGreen, and (2) related activities mainly in European research. Links between research and policy-making as two activities that should go hand in hand...

  7. Directionally Solidified Multifunctional Ceramics

    Science.gov (United States)

    2006-12-01

    Vidrio , Vol. 44 [5] (2005) pp 347 - 352. 9. F. W. Dynys and A. Sayir, "Self Assemble Silicide Architectures by Directional Solidification," Journal...Sociedad Espanola de Ceramica y Vidrio , Vol. 43 [4] (2004) pp 753 - 758. 21. A. Sayir and F. S. Lowery, "Combustion-Resistance of Silicon-Based Ceramics...Espafiola de Cerdmica y Vidrio , Vol. 43 [3], 2004. ISSN-0366-3175-BSCVB9. 14 37. P. Berger, A. Sayir and M. H. Berger, "Nuclear Microprobe using Elastic

  8. Direct access to INIS

    International Nuclear Information System (INIS)

    Zheludev, I.S.; Romanenko, A.G.

    1981-01-01

    Librarians, researchers, and information specialists throughout the world now have the opportunity for direct access to coverage of almost 95% of the world's literature dealing with the peaceful uses of atomic energy and nuclear science. This opportunity has been provided by the International Nuclear Information System (INIS) of the IAEA. INIS, with the voluntary collaboration of more than 60 of the Agency's Member States, maintains a comprehensive, computer-resident data-base, containing the bibliographic details plus informative abstracts of the bulk of the world's literature on nuclear science and technology. Since this data-base is growing at a rate of 75,000 items per year, and already contains more than 500,000 items, it is obviously important to be able to search this collection conveniently and efficiently. The usefulness of this ability is enhanced when other data-bases on related subjects are made available on an information network. During the early 1970s, on-line interrogation of large bibliographic data-bases became the accepted method for searching this type of information resource. Direct interaction between the searcher and the data-base provides quick feed-back resulting in improved literature listings for launching research and development projects. On-line access enables organizations which cannot store a large data-base on their own computer to expand the information resources at their command. Because of these advantages, INIS undertook to extend to interested Member States on-line access to its data-base in Vienna

  9. Direct thermal dyes

    Science.gov (United States)

    Ehlinger, Edward

    1990-07-01

    Direct thermal dyes are members of a class of compounds referred to in the imaging industry as color formers or leuco dyes. The oldest members of that class have simple triarylmethane structures, and have been employed for years in various dyeing applications. More complex triarylmethane compounds, such as phthalides and fluorans, are now used in various imaging systems to produce color. Color is derived from all of these compounds via the same mechanism, on a molecular level. That is, an event of activation produces a highly resonating cationic system whose interaction with incident light produces reflected light of a specific color. The activation event in the case of a direct thermal system is the creation of a melt on the paper involving dye and an acidic developer. The three major performance parameters in a thermal system are background color, image density, and image stability. The three major dye physical parameters affecting thermal performance are chemical constituency, purity, and particle size. Those dyes having the best combination of characteristics which can also be manufactured economically dominate the marketplace. Manufacturing high performance dyes for the thermal market involves multi-step, convergent reaction sequences performed on large scale. Intermediates must be manufactured at the right time, and at the right quality to be useful.

  10. Remote direct memory access

    Science.gov (United States)

    Archer, Charles J.; Blocksome, Michael A.

    2012-12-11

    Methods, parallel computers, and computer program products are disclosed for remote direct memory access. Embodiments include transmitting, from an origin DMA engine on an origin compute node to a plurality target DMA engines on target compute nodes, a request to send message, the request to send message specifying a data to be transferred from the origin DMA engine to data storage on each target compute node; receiving, by each target DMA engine on each target compute node, the request to send message; preparing, by each target DMA engine, to store data according to the data storage reference and the data length, including assigning a base storage address for the data storage reference; sending, by one or more of the target DMA engines, an acknowledgment message acknowledging that all the target DMA engines are prepared to receive a data transmission from the origin DMA engine; receiving, by the origin DMA engine, the acknowledgement message from the one or more of the target DMA engines; and transferring, by the origin DMA engine, data to data storage on each of the target compute nodes according to the data storage reference using a single direct put operation.

  11. Direct neutrino mass measurements

    Energy Technology Data Exchange (ETDEWEB)

    Weinheimer, Christian, E-mail: weinheimer@uni-muenster.de [Westfaelische Wilhelms-Universitaet, Institut fuer Kernphysik (Germany)

    2013-03-15

    Direct neutrino mass experiments are complementary to searches for neutrinoless double {beta}-decay and to analyses of cosmological data. The previous tritium beta decay experiments at Mainz and at Troitsk have achieved upper limits on the neutrino mass of about 2 eV/c{sup 2} . The KATRIN experiment under construction will improve the neutrino mass sensitivity down to 200 meV/c{sup 2} by increasing strongly the statistics and-at the same time-reducing the systematic uncertainties. Huge improvements have been made to operate the system extremely stably and at very low background rate. The latter comprises new methods to reject secondary electrons from the walls as well as to avoid and to eject electrons stored in traps. As an alternative to tritium {beta}-decay experiments cryo-bolometers investigating the endpoint region of {sup 187}Re {beta}-decay or the electron capture of {sup 163}Ho are being developed. This article briefly reviews the current status of the direct neutrino mass measurements.

  12. Direct saccharification of milo

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-28

    Crude or unrefined milo grain is pulverized to less than 100 mesh, suspended in water, and directly saccharified with enzymes. Thus, 10 kg of pulverized milo (100 mesh) was suspended in 20 liters water, liquified in the presence of bacterial amylase at 90/sup 0/ for 30 minutes and autoclaved for 10 minutes at 120/sup 0/, the liquifaction autoclave procedures were then repeated. The liquified preparation was saccharified in the presence of bacterial glucoamylase at 55/sup 0/ for 72 hours. The percentage saccharification of unrefined milo was 92-97%, which was comparable to that obtained with refined milo or a milo starch preparation. The saccharified milo preparation, when used as a sugar source in glutamic acid, lysine, or inosine fermentation, also showed similar efficiency to that of saccharified milo starch.

  13. Site directed recombination

    Science.gov (United States)

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  14. Nanoparticles and direct immunosuppression

    Science.gov (United States)

    Ngobili, Terrika A

    2016-01-01

    Targeting the immune system with nanomaterials is an intensely active area of research. Specifically, the capability to induce immunosuppression is a promising complement for drug delivery and regenerative medicine therapies. Many novel strategies for immunosuppression rely on nanoparticles as delivery vehicles for small-molecule immunosuppressive compounds. As a consequence, efforts in understanding the mechanisms in which nanoparticles directly interact with the immune system have been overshadowed. The immunological activity of nanoparticles is dependent on the physiochemical properties of the nanoparticles and its subsequent cellular internalization. As the underlying factors for these reactions are elucidated, more nanoparticles may be engineered and evaluated for inducing immunosuppression and complementing immunosuppressive drugs. This review will briefly summarize the state-of-the-art and developments in understanding how nanoparticles induce immunosuppressive responses, compare the inherent properties of nanomaterials which induce these immunological reactions, and comment on the potential for using nanomaterials to modulate and control the immune system. PMID:27229901

  15. Directionally positionable neutron beam

    International Nuclear Information System (INIS)

    Dance, W.E.; Bumgardner, H.M.

    1981-01-01

    Disclosed is apparatus for forming and directionally positioning a neutron beam. The apparatus includes an enclosed housing rotatable about a first axis with a neutron source axially positioned on the axis of rotation of the enclosed housing but not rotating with the housing. The rotatable housing is carried by a vertically positionable arm carried on a mobile transport. A collimator is supported by the rotatable housing and projects into the housing to orientationally position its inlet window at an adjustably fixed axial and radial spacing from the neutron source so that rotation of the enclosed housing causes the inlet window to rotate about a circle which is a fixed axial distance from the neutron source and has the axis of rotation of the housing as its center. (author)

  16. Directional epithermal neutron detector

    International Nuclear Information System (INIS)

    Givens, W.W.; Mills, W.R. Jr.

    1986-01-01

    A borehole tool for epithermal neutron die-away logging of subterranean formations surrounding a borehole is described which consists of: (a) a pulsed source of fast neutrons for irradiating the formations surrounding a borehole, (b) at least one neutron counter for counting epithermal neutrons returning to the borehole from the irradiated formations, (c) a neutron moderating material, (d) an outer thermal neutron shield providing a housing for the counter and the moderating material, (e) an inner thermal neutron shield dividing the housing so as to provide a first compartment bounded by the inner thermal neutron shield and a first portion of the outer thermal neutron shield and a second compartment bounded by the inner thermal neutron shield and a second portion of the outer thermal neutron shield, the counter being positioned within the first compartment and the moderating material being positioned within the second compartment, and (f) means for positioning the borehole tool against one side of the borehole wall and azimuthally orienting the borehole tool such that the first chamber is in juxtaposition with the borehole wall, the formation epithermal neutrons penetrating into the first chamber through the first portion of the outer thermal neutron shield are detected by the neutron counter for die-away measurement, thereby maximizing the directional sensitivty of the neutron counter to formation epithermal neutrons, the borehole fluid epithermal neutrons penetrating into the second chamber through the second chamber through the second portion of the outer thermal neutron shield are largely slowed down and lowered in energy by the moderating material and absorbed by the inner thermal neutron shield before penetrating into the first chamber, thereby minimizing the directional sensitivity of the neutron counter to borehole fluid epithermal neutrons

  17. The spin relaxation of nitrogen donors in 6H SiC crystals as studied by the electron spin echo method

    Energy Technology Data Exchange (ETDEWEB)

    Savchenko, D., E-mail: dariyasavchenko@gmail.com [Institute of Physics of the Czech Academy of Sciences, Prague 182 21 (Czech Republic); National Technical University of Ukraine “Kyiv Polytechnic Institute,” Kyiv 03056 (Ukraine); Shanina, B.; Kalabukhova, E. [V.E. Lashkaryov Institute of Semiconductor Physics, NASU, Kyiv 03028 (Ukraine); Pöppl, A. [Institute of Experimental Physics II, Leipzig University, Leipzig D-04103 (Germany); Lančok, J. [Institute of Physics of the Czech Academy of Sciences, Prague 182 21 (Czech Republic); Mokhov, E. [A.F. Ioffe Physical Technical Institute, RAS, St. Petersburg 194021 (Russian Federation); Saint-Petersburg National Research University of Information Technologies, Mechanics and Optics, St. Petersburg 19710 (Russian Federation)

    2016-04-07

    We present the detailed study of the spin kinetics of the nitrogen (N) donor electrons in 6H SiC wafers grown by the Lely method and by the sublimation “sandwich method” (SSM) with a donor concentration of about 10{sup 17 }cm{sup −3} at T = 10–40 K. The donor electrons of the N donors substituting quasi-cubic “k1” and “k2” sites (N{sub k1,k2}) in both types of the samples revealed the similar temperature dependence of the spin-lattice relaxation rate (T{sub 1}{sup −1}), which was described by the direct one-phonon and two-phonon processes induced by the acoustic phonons proportional to T and to T{sup 9}, respectively. The character of the temperature dependence of the T{sub 1}{sup −1} for the donor electrons of N substituting hexagonal (“h”) site (N{sub h}) in both types of 6H SiC samples indicates that the donor electrons relax through the fast-relaxing centers by means of the cross-relaxation process. The observed enhancement of the phase memory relaxation rate (T{sub m}{sup −1}) with the temperature increase for the N{sub h} donors in both types of the samples, as well as for the N{sub k1,k2} donors in Lely grown 6H SiC, was explained by the growth of the free electron concentration with the temperature increase and their exchange scattering at the N donor centers. The observed significant shortening of the phase memory relaxation time T{sub m} for the N{sub k1,k2} donors in the SSM grown sample with the temperature lowering is caused by hopping motion of the electrons between the occupied and unoccupied states of the N donors at N{sub h} and N{sub k1,k2} sites. The impact of the N donor pairs, triads, distant donor pairs formed in n-type 6H SiC wafers on the spin relaxation times was discussed.

  18. Coatings for directional eutectics

    Science.gov (United States)

    Rairden, J. R.; Jackson, M. R.

    1976-01-01

    Coatings developed to provide oxidation protection for the directionally-solidified eutectic alloy NiTaC-B (4.4 weight percent Cr) were evaluated. Of seven Co-, Fe- and Ni-base coatings that were initially investigated, best resistance to cyclic oxidation was demonstrated by duplex coatings fabricated by depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam source followed by deposition of an Al overlayer using the pack cementation process. It was found that addition of carbon to the coating alloy substantially eliminated the problem of fiber denudation in TaC-type eutectic alloys. Burner rig cycled NiTaC-B samples coated with Ni-20Cr-5Al-0.1C-0.1Y+Al and rupture-tested at 1100 deg C performed as well as or better than uncoated, vacuum cycled and air-tested NiTaC-13; however, a slight degradation with respect to uncoated material was noted in air-stress rupture tests at 870 deg C for both cycled and uncycled samples.

  19. New directions in Guatemala.

    Science.gov (United States)

    1997-02-01

    This news brief relates some new directions, since its inception in 1988, which the Family Welfare Association of Guatemala (APROFAM) will be undertaking during 1996-97. In December 1997, APROFAM restructured its program to include reproductive health services with family planning services. The program will target rural Mayan communities. The program will be working toward service sustainability, due to reduced external support. In October 1996 a new board was established that will focus on marketing, IEC, finance and administration, rural development, and clinical services. Meetings between the new board of directors of APROFAM and JOICFP focused on the use of integrated programs as a model for widespread programming among the rural Mayan population. The integrated program that was implemented by JOICFP was successful in reaching Mayan communities of Solola. This population was difficult to reach with conventional family planning approaches. The integrated program was successful in establishing trust with and participation of the rural Mayans. Activities such as parasite control, skills training, and income generation for women were useful in establishing trust and promoting self-reliance. Integrated programs will refocus on family planning and developing self-reliance. The UNFPA will be conducting an annual internal evaluation as a means of sharing information and deepening understanding of project implementation.

  20. Direct UV-written broadband directional broadband planar waveguide couplers

    DEFF Research Database (Denmark)

    Olivero, Massimo; Svalgaard, Mikael

    2005-01-01

    We report the fabrication of broadband directional couplers by direct UV-writing. The fabrication process is shown to be beneficial, robust and flexible. The components are compact and show superior performance in terms of loss and broadband operation.......We report the fabrication of broadband directional couplers by direct UV-writing. The fabrication process is shown to be beneficial, robust and flexible. The components are compact and show superior performance in terms of loss and broadband operation....

  1. Estimation of directional wave spreading

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Bhat, S.S.; Anand, N.M.; Nayak, B.U.

    Directional properties of ocean waves are of great economic interest. The knowledge of wave directionality is important for the design of maritime structures and offshore operations. Two main aspects are considered for this study for the data...

  2. Estimation of wave directional spreading

    Digital Repository Service at National Institute of Oceanography (India)

    Deo, M.C.; Gondane, D.S.; SanilKumar, V.

    One of the useful measures of waves directional spreading at a given location is the directional spreading parameter. This paper presents a new approach to arrive at its characteristic value using the computational technique of Artificial Neural...

  3. Geothermal Technologies Program: Direct Use

    Energy Technology Data Exchange (ETDEWEB)

    2004-08-01

    This general publication describes geothermal direct use systems, and how they have been effectively used throughout the country. It also describes the DOE program R&D efforts in this area, and summarizes several projects using direct use technology.

  4. Innovative tool of direct marketing

    OpenAIRE

    T.S. Maksymova

    2010-01-01

    The aspects of direct marketing activation on the basis of interactive applications introduction are examined. Basic advantages, linked with the use of the integrated marketing communications during formation of direct marketing strategies are open up.

  5. Direct channel problems and phenomena

    International Nuclear Information System (INIS)

    Cutkosky, R.E.

    1975-01-01

    Direct channel problems and phenomena are considered covering the need for precision hadron spectroscopy, the data base for precision hadron spectroscopy, some relations between direct-channel and cross-channel effects, and spin rotation phenomena

  6. Directional wave measurements and modelling

    Digital Repository Service at National Institute of Oceanography (India)

    Anand, N.M.; Nayak, B.U.; Bhat, S.S.; SanilKumar, V.

    Some of the results obtained from analysis of the monsoon directional wave data measured over 4 years in shallow waters off the west coast of India are presented. The directional spectrum computed from the time series data seems to indicate...

  7. Psychiatric Advance Directives: Getting Started

    Science.gov (United States)

    ... News Legal Issues Search for: About PADs A psychiatric advance directive (PAD) is a legal document that ... decisions during a mental health crisis. Getting Started Psychiatric advance directives (PADs) are relatively new legal instruments ...

  8. Seveso directive: the leading innovations

    International Nuclear Information System (INIS)

    Cozzani, V.; Zanelli, S.

    1998-01-01

    Directive 96/82/EC on the control of major accident hazards caused by dangerous substances, also known as 'Seveso-II' Directive, was adopted by the European Council on December 1996. The member states of the European Community shall bring into force the Directive not later than February 1999. Some innovative aspects of the Directive are discussed. In particular, this paper focuses on the effects of the new criteria for the identification of establishments to which the Directive obligations will apply and for land use planning in the vicinity of the establishments [it

  9. Dynamic behaviors in directed networks

    International Nuclear Information System (INIS)

    Park, Sung Min; Kim, Beom Jun

    2006-01-01

    Motivated by the abundance of directed synaptic couplings in a real biological neuronal network, we investigate the synchronization behavior of the Hodgkin-Huxley model in a directed network. We start from the standard model of the Watts-Strogatz undirected network and then change undirected edges to directed arcs with a given probability, still preserving the connectivity of the network. A generalized clustering coefficient for directed networks is defined and used to investigate the interplay between the synchronization behavior and underlying structural properties of directed networks. We observe that the directedness of complex networks plays an important role in emerging dynamical behaviors, which is also confirmed by a numerical study of the sociological game theoretic voter model on directed networks

  10. Direct photons in WA98

    CERN Document Server

    Aggarwal, M M; Ahammed, Z; Angelis, Aris L S; Antonenko, V G; Arefev, V; Astakhov, V A; Avdeichikov, V; Awes, T C; Baba, P V K S; Badyal, S K; Barlag, C; Bathe, S; Batyunya, B; Bernier, T; Bhalla, K B; Bhatia, V S; Blume, C; Bock, R; Bohne, E M; Böröcz, Z K; Bucher, D; Buijs, A; Büsching, H; Carlén, L; Chalyshev, V; Chattopadhyay, S; Cherbachev, R; Chujo, T; Claussen, A; Das, A C; Decowski, M P; Delagrange, H; Dzhordzhadze, V; Dönni, P; Dubovik, I; Dutt, S; Dutta-Majumdar, M R; El-Chenawi, K F; Eliseev, S; Enosawa, K; Foka, P Y; Fokin, S L; Ganti, M S; Garpman, S; Gavrishchuk, O P; Geurts, F J M; Ghosh, T K; Glasow, R; Gupta, S K; Guskov, B; Gustafsson, Hans Åke; Gutbrod, H H; Higuchi, R; Hrivnacova, I; Ippolitov, M S; Kalechofsky, H; Kamermans, R; Kampert, K H; Karadzhev, K; Karpio, K; Kato, S; Kees, S; Klein-Bösing, C; Knoche, S; Kolb, B W; Kosarev, I G; Kucheryaev, I; Krümpel, T; Kugler, A; Kulinich, P A; Kurata, M; Kurita, K; Kuzmin, N A; Langbein, I; Lee, Y Y; Löhner, H; Luquin, Lionel; Mahapatra, D P; Man'ko, V I; Martin, M; Martínez, G; Maksimov, A; Mgebrishvili, G; Miake, Y; Mir, M F; Mishra, G C; Miyamoto, Y; Mohanty, B; Morrison, D; Mukhopadhyay, D S; Naef, H; Nandi, B K; Nayak, S K; Nayak, T K; Neumaier, S; Nyanin, A; Nikitin, V A; Nikolaev, S; Nilsson, P O; Nishimura, S; Nomokonov, V P; Nystrand, J; Obenshain, F E; Oskarsson, A; Otterlund, I; Pachr, M; Pavlyuk, S; Peitzmann, Thomas; Petracek, V; Pinganaud, W; Plasil, F; Von Poblotzki, U; Purschke, M L; Rak, J; Raniwala, R; Raniwala, S; Ramamurthy, V S; Rao, N K; Retière, F; Reygers, K; Roland, G; Rosselet, L; Rufanov, I A; Roy, C; Rubio, J M; Sako, H; Sambyal, S S; Santo, R; Sato, S; Schlagheck, H; Schmidt, H R; Schutz, Y; Shabratova, G; Shah, T H; Sibiryak, Yu; Siemiarczuk, T; Silvermyr, D; Sinha, B C; Slavin, N V; Söderström, K; Solomey, Nickolas; Sood, G; Sørensen, S P; Stankus, P; Stefanek, G; Steinberg, P; Stenlund, E; Stüken, D; Sumbera, M; Svensson, S; Trivedi, M D; Tsvetkov, A A; Tykarski, L; Urbahn, J; Van den Pijll, E C; van Eijndhoven, N; van Nieuwenhuizen, G J; Vinogradov, A; Viyogi, Y P; Vodopyanov, A S; Vörös, S; Wyslouch, B; Yagi, K; Yokota, Y; Young, G R

    2002-01-01

    A measurement of direct photon production in /sup 208/Pb+/sup 208/Pb collisions at 158 A GeV has been carried out in the CERN WA98 experiment. The invariant yield of direct photons was extracted as a function of transverse momentum in the interval 0.51.5 GeV/c. the result constitutes the first observation of direct photons in ultrarelativistic heavy-ion collisions. (19 refs).

  11. Direct cooled power electronics substrate

    Science.gov (United States)

    Wiles, Randy H [Powell, TN; Wereszczak, Andrew A [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Lowe, Kirk T [Knoxville, TN

    2010-09-14

    The disclosure describes directly cooling a three-dimensional, direct metallization (DM) layer in a power electronics device. To enable sufficient cooling, coolant flow channels are formed within the ceramic substrate. The direct metallization layer (typically copper) may be bonded to the ceramic substrate, and semiconductor chips (such as IGBT and diodes) may be soldered or sintered onto the direct metallization layer to form a power electronics module. Multiple modules may be attached to cooling headers that provide in-flow and out-flow of coolant through the channels in the ceramic substrate. The modules and cooling header assembly are preferably sized to fit inside the core of a toroidal shaped capacitor.

  12. Epidemic threshold in directed networks

    Science.gov (United States)

    Li, Cong; Wang, Huijuan; Van Mieghem, Piet

    2013-12-01

    Epidemics have so far been mostly studied in undirected networks. However, many real-world networks, such as the online social network Twitter and the world wide web, on which information, emotion, or malware spreads, are directed networks, composed of both unidirectional links and bidirectional links. We define the directionality ξ as the percentage of unidirectional links. The epidemic threshold τc for the susceptible-infected-susceptible (SIS) epidemic is lower bounded by 1/λ1 in directed networks, where λ1, also called the spectral radius, is the largest eigenvalue of the adjacency matrix. In this work, we propose two algorithms to generate directed networks with a given directionality ξ. The effect of ξ on the spectral radius λ1, principal eigenvector x1, spectral gap (λ1-λ2), and algebraic connectivity μN-1 is studied. Important findings are that the spectral radius λ1 decreases with the directionality ξ, whereas the spectral gap and the algebraic connectivity increase with the directionality ξ. The extent of the decrease of the spectral radius depends on both the degree distribution and the degree-degree correlation ρD. Hence, in directed networks, the epidemic threshold is larger and a random walk converges to its steady state faster than that in undirected networks with the same degree distribution.

  13. Seeking coherence among environmental directives

    NARCIS (Netherlands)

    Beijen, Barbara

    2014-01-01

    European environmental law consists of a large number of directives and regulations dealing with environmental domains such as air, water, or waste, or with issues such as greenhouse gases, chemicals or industrial emissions. These directives and regulations do not form a comprehensive system of

  14. Direct activation of microcrystalline zeolites

    NARCIS (Netherlands)

    Ortiz-Iniesta, Maria Jesus; Heeres, Hero Jan; Melian-Cabrera, Ignacio

    2013-01-01

    In this work a direct activation route of zeolites is assessed. It consists of NH4-exchanging the as-synthesized solids before removing the organic template. Calcination afterwards serves to combust the organic template and creates the Bronsted sites directly; thus applying merely a single thermal

  15. Type-Directed Partial Evaluation

    DEFF Research Database (Denmark)

    Danvy, Olivier

    1998-01-01

    Type-directed partial evaluation uses a normalization function to achieve partial evaluation. These lecture notes review its background, foundations, practice, and applications. Of specific interest is the modular technique of offline and online type-directed partial evaluation in Standard ML...

  16. Exchange effects in direct reactions

    International Nuclear Information System (INIS)

    LeMere, M.; Kanellopoulos, E.J.; Suenkel, W.; Tang, Y.C.

    1979-01-01

    The effect of antisymmetrization in direct reactions is examined by studying the properties of the coupling-normalization kernel function occurring in a resonating-group formulation. From this study, one obtains useful information concerning the general behavior of direct-reactiion processes and some justification for the use of three-body models in phenomenological analyses

  17. Type-Directed Partial Evaluation

    DEFF Research Database (Denmark)

    Danvy, Olivier

    1998-01-01

    Type-directed partial evaluation uses a normalization function to achieve partial evaluation. These lecture notes review its background, foundations, practice, and applications. Of specific interest is the modular technique of offline and online type-directed partial evaluation in Standard ML of ...

  18. Eldercare at Home: Advanced Directives

    Science.gov (United States)

    ... permanently? Helping the person fill out a living will (advance directive) A living will states a person's wishes about medical care if ... never be in a situation where another person will have to make decisions ... it is to have an advance directive. However, don't assume that your loved ...

  19. New directions in information organization

    CERN Document Server

    Park, Jung-ran; Spink, Amanda

    2013-01-01

    New Directions in Information Organization, co-edited by Dr. Jung-ran Park and Dr. Lynne Howarth seeks to provide an overview and understanding of the future directions, leading edge theories and models for research and practice in information organization.

  20. Target selection for direct marketing.

    NARCIS (Netherlands)

    Bult, Jan Roelf

    1993-01-01

    In this thesis we concentrated on the use ol direct mail for targeting potential buyers. The major characteristics that influences the success of a plomotional direct mail campaign are the of-fbr,the communication elements, the timing or sequence of these communication elements, and the list of

  1. Direct oral anticoagulants: An update.

    Science.gov (United States)

    Franco Moreno, Ana Isabel; Martín Díaz, Rosa María; García Navarro, María José

    2017-12-30

    Vitamin K antagonists were the only choice for chronic oral anticoagulation for more than half a century. Over the past few years, direct oral anticoagulants have emerged, including one direct thrombin inhibitor (dabigatran etexilate) and three factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). In randomised controlled trials comparing direct oral anticoagulants with traditional vitamin K antagonists, the direct oral anticoagulants all showed a favourable benefit-risk balance in their safety and efficacy profile, in prevention of thromboembolic events in patients with atrial fibrillation and in the prevention and treatment of venous thromboembolism and acute coronary syndrome. In 2008, dabigatran was the first direct oral anticoagulant approved by the European Medicine Agency. Subsequently, rivaroxaban, apixaban and edoxaban were also authorised. This article reviews the evidence related to the use of these drugs. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  2. Efficient Placement of Directional Antennas

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Feng [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory

    2010-09-20

    Directional antenna is an technology for the proliferation of wireless networks. In centralized wireless network, wireless devices communicate through base stations. Directed antennas are placed on base stations and form a backbone of communication. The communication between base stations and wireless devices can be interfered due to a large number of wireless device. Methodically positioning and orienting directed antennas can help to reduce the interference while saving energy. An integer linear programming is developed for siting and directing antennas on multiple base stations, and this formulation can be extended to model non-overlapping channels. Through the integer programming formulation, optimal antenna positions can be used to analyze the performance of directed antennas with different parameters like the number base stations and the number of non-overlapping channels.

  3. Direct catastrophic injury in sports.

    Science.gov (United States)

    Boden, Barry P

    2005-11-01

    Catastrophic sports injuries are rare but tragic events. Direct (traumatic) catastrophic injury results from participating in the skills of a sport, such as a collision in football. Football is associated with the greatest number of direct catastrophic injuries for all major team sports in the United States. Pole vaulting, gymnastics, ice hockey, and football have the highest incidence of direct catastrophic injuries for sports in which males participate. In most sports, the rate of catastrophic injury is higher at the collegiate than at the high school level. Cheerleading is associated with the highest number of direct catastrophic injuries for all sports in which females participate. Indirect (nontraumatic) injury is caused by systemic failure as a result of exertion while participating in a sport. Cardiovascular conditions, heat illness, exertional hyponatremia, and dehydration can cause indirect catastrophic injury. Understanding the common mechanisms of injury and prevention strategies for direct catastrophic injuries is critical in caring for athletes.

  4. Potential theory for directed networks.

    Directory of Open Access Journals (Sweden)

    Qian-Ming Zhang

    Full Text Available Uncovering factors underlying the network formation is a long-standing challenge for data mining and network analysis. In particular, the microscopic organizing principles of directed networks are less understood than those of undirected networks. This article proposes a hypothesis named potential theory, which assumes that every directed link corresponds to a decrease of a unit potential and subgraphs with definable potential values for all nodes are preferred. Combining the potential theory with the clustering and homophily mechanisms, it is deduced that the Bi-fan structure consisting of 4 nodes and 4 directed links is the most favored local structure in directed networks. Our hypothesis receives strongly positive supports from extensive experiments on 15 directed networks drawn from disparate fields, as indicated by the most accurate and robust performance of Bi-fan predictor within the link prediction framework. In summary, our main contribution is twofold: (i We propose a new mechanism for the local organization of directed networks; (ii We design the corresponding link prediction algorithm, which can not only testify our hypothesis, but also find out direct applications in missing link prediction and friendship recommendation.

  5. Direct Manipulation in Virtual Reality

    Science.gov (United States)

    Bryson, Steve

    2003-01-01

    Virtual Reality interfaces offer several advantages for scientific visualization such as the ability to perceive three-dimensional data structures in a natural way. The focus of this chapter is direct manipulation, the ability for a user in virtual reality to control objects in the virtual environment in a direct and natural way, much as objects are manipulated in the real world. Direct manipulation provides many advantages for the exploration of complex, multi-dimensional data sets, by allowing the investigator the ability to intuitively explore the data environment. Because direct manipulation is essentially a control interface, it is better suited for the exploration and analysis of a data set than for the publishing or communication of features found in that data set. Thus direct manipulation is most relevant to the analysis of complex data that fills a volume of three-dimensional space, such as a fluid flow data set. Direct manipulation allows the intuitive exploration of that data, which facilitates the discovery of data features that would be difficult to find using more conventional visualization methods. Using a direct manipulation interface in virtual reality, an investigator can, for example, move a data probe about in space, watching the results and getting a sense of how the data varies within its spatial volume.

  6. Potential Theory for Directed Networks

    Science.gov (United States)

    Zhang, Qian-Ming; Lü, Linyuan; Wang, Wen-Qiang; Zhou, Tao

    2013-01-01

    Uncovering factors underlying the network formation is a long-standing challenge for data mining and network analysis. In particular, the microscopic organizing principles of directed networks are less understood than those of undirected networks. This article proposes a hypothesis named potential theory, which assumes that every directed link corresponds to a decrease of a unit potential and subgraphs with definable potential values for all nodes are preferred. Combining the potential theory with the clustering and homophily mechanisms, it is deduced that the Bi-fan structure consisting of 4 nodes and 4 directed links is the most favored local structure in directed networks. Our hypothesis receives strongly positive supports from extensive experiments on 15 directed networks drawn from disparate fields, as indicated by the most accurate and robust performance of Bi-fan predictor within the link prediction framework. In summary, our main contribution is twofold: (i) We propose a new mechanism for the local organization of directed networks; (ii) We design the corresponding link prediction algorithm, which can not only testify our hypothesis, but also find out direct applications in missing link prediction and friendship recommendation. PMID:23408979

  7. Proximinality in generalized direct sums

    Directory of Open Access Journals (Sweden)

    Darapaneni Narayana

    2004-01-01

    Full Text Available We consider proximinality and transitivity of proximinality for subspaces of finite codimension in generalized direct sums of Banach spaces. We give several examples of Banach spaces where proximinality is transitive among subspaces of finite codimension.

  8. EOP Current Magnitude and Direction

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data contain shipboard current magnitudes and directions collected in the Pacific, both pelagic and near shore environments. Data is collected using an RD...

  9. Law, autonomy and advance directives.

    Science.gov (United States)

    Willmott, Lindy; White, Ben; Mathews, Ben

    2010-12-01

    The principle of autonomy underpins legal regulation of advance directives that refuse life-sustaining medical treatment. The primacy of autonomy in this domain is recognised expressly in the case law, through judicial pronouncement, and implicitly in most Australian jurisdictions, through enactment into statute of the right to make an advance directive. This article seeks to justify autonomy as an appropriate principle for regulating advance directives and relies on three arguments: the necessity of autonomy in a liberal democracy; the primacy of autonomy in medical ethics discourse; and the uncontested importance of autonomy in the law on contemporaneous refusal of medical treatment. This article also responds to key criticisms that autonomy is not an appropriate organising principle to underpin legal regulation of advance directives.

  10. Directed Energy for Interstellar Study

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to expand our investigations started in our NIAC Phase I of using directed energy to allow the achievement of relativistic flight to pave the way to the...

  11. Foreign direct investment in China

    OpenAIRE

    Bredero, Q.S.

    2007-01-01

    Foreign Direct Investment in China is one of the most comprehensive studies of FDI in China and provides a remarkable background of information on the evolution of China’s FDI policies over the last 30 years.

  12. Direction-dependent exponential biassing

    International Nuclear Information System (INIS)

    Bending, R.C.

    1974-01-01

    When Monte Carlo methods are applied to penetration problems, the use of variance reduction techniques is essential if realistic computing times are to be achieved. A technique known as direction-dependent exponential biassing is described which is simple to apply and therefore suitable for problems with difficult geometry. The material cross section in any region is multiplied by a factor which depends on the particle direction, so that particles travelling in a preferred direction ''see'' a smaller cross section than those travelling in the opposite direction. A theoretical study shows that substantial gains may be obtained, and that the choice of biassing parameter is not critical. The method has been implemented alongside other importance sampling techniques in the general Monte Carlo code SPARTAN, and results obtained for simple problems using this code are included. 4 references. (U.S.)

  13. New directions in tokamak reactors

    International Nuclear Information System (INIS)

    Baker, C.C.

    1985-01-01

    New directions for tokamak research are briefly mentioned. Some of the areas for new considerations are the following: reactor size, beta ratio, current drivers, blankets, impurity control, and modular designs

  14. Directional spectrum of ocean waves

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A; Gouveia, A; Nagarajan, R.

    This paper describes a methodology for obtaining the directional spectrum of ocean waves from time series measurement of wave elevation at several gauges arranged in linear or polygonal arrays. Results of simulated studies using sinusoidal wave...

  15. Directed Innovation of Business Models

    Directory of Open Access Journals (Sweden)

    Stelian Brad

    2016-06-01

    Full Text Available Business model innovation is an important issue to keep business competitive and increase company’s profits. Due to many market attractors, identification of appropriate paths of business model evolution is a painful and risky process. To improve decision’s effectiveness in this process, an architectural construct of analysis and conceptualization for business model innovation that combines directed evolution and blue ocean concepts is proposed in this paper under the name of directed innovation. It displays the key points where innovations would happen to direct adaptation of the business model towards sustainable competitiveness. Formulation of mature solutions is supported by inventive problem solving tools. The significance of the directed innovation approach is demonstrated in a case study dealing with business model innovation of a software company.

  16. Multi-Directional Experimental Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The ATLSS Multi-directional Experimental Laboratory was constructed in 1987 under funding from the National Science Foundation to be a major facility for large-scale...

  17. Spontaneous direct and reverse osmosis

    International Nuclear Information System (INIS)

    Valitov, N.Kh.

    1996-01-01

    It has been ascertained experimentally that in the course of separation of CsCl, KCl, NaCl aqueous solutions by semi-permeable membrane from distilled water the direct and then reverse osmosis are observed. The same sequence is observed in case of separation of CsCl aqueous solutions from NaCl of different concentrations. The reason for the direct and reverse osmosis has been explained. 5 refs.; 3 figs. 1 tab

  18. Spillovers from Foreign Direct Investment

    DEFF Research Database (Denmark)

    Meyer, Klaus E.; Sinani, Evis

    2005-01-01

    The extensive empirical literature analyzing productivity spillovers from foreign direct investment to local firms provides inconclusive results. Some studies find that foreign presence has a positive impact on the productivity of domestic firms, while others find no evidence or a negative effect...... for industrialized countries in the 1990s. Transition economies may experience spillovers, but these have been declining in recent years. Keywords: developing countries, transition economies, spillovers, foreign direct investment, technology transfer, meta-analysis...

  19. Quantum direct communication with authentication

    International Nuclear Information System (INIS)

    Lee, Hwayean; Lim, Jongin; Yang, HyungJin

    2006-01-01

    We propose two quantum direct communication (QDC) protocols with user authentication. Users can identify each other by checking the correlation of Greenberger-Horne-Zeilinger (GHZ) states. Alice can directly send a secret message to Bob without any previously shared secret using the remaining GHZ states after authentication. Our second QDC protocol can be used even though there is no quantum link between Alice and Bob. The security of the transmitted message is guaranteed by properties of entanglement of GHZ states

  20. Direct Bandgap Group IV Materials

    Science.gov (United States)

    2016-01-21

    AFRL-AFOSR-JP-TR-2017-0049 Direct Bandgap group IV Materials Hung Hsiang Cheng NATIONAL TAIWAN UNIVERSITY Final Report 01/21/2016 DISTRIBUTION A...NAME(S) AND ADDRESS(ES) NATIONAL TAIWAN UNIVERSITY 1 ROOSEVELT RD. SEC. 4 TAIPEI CITY, 10617 TW 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING...14. ABSTRACT Direct bandgap group IV materials have been long sought for in both academia and industry for the implementation of photonic devices

  1. Geothermal Direct Heat Application Potential

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, Paul J

    1989-01-01

    The geothermal direct-use industry growth trends, potential, needs, and how they can be met, are addressed. Recent investigations about the current status of the industry and the identification of institutional and technical needs provide the basis on which this paper is presented. Initial drilling risk is the major obstacle to direct-use development. The applications presented include space and district heating projects, heat pumps (heating and cooling), industrial processes, resorts and pools, aquaculture and agriculture.

  2. 75 FR 76630 - Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad-Direct...

    Science.gov (United States)

    2010-12-09

    ....S. Direct Investment Abroad--Direct Transactions of U.S. Reporter With Foreign Affiliate.'' The..., Quarterly Survey of U.S. Direct Investment Abroad--Direct Transactions of U.S. Reporter With Foreign...] RIN 0691--AA75 Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad...

  3. Direct conversion of fusion energy

    International Nuclear Information System (INIS)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D- 3 He reaction and the p- 11 B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger βB 2 0 to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high β values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D- 3 He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D 3 He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D 3 He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion or liquid metal MHD conversion (LMMHD). For a D

  4. Direct conversion of fusion energy

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Markus

    2003-03-01

    Deuterium and tritium are expected to be used as fuel in the first fusion reactors. Energy is released as kinetic energy of ions and neutrons, when deuterium reacts with tritium. One way to convert the kinetic energy to electrical energy, is to let the ions and neutrons hit the reactor wall and convert the heat that is caused by the particle bombardment to electrical energy with ordinary thermal conversion. If the kinetic energy of the ions instead is converted directly to electrical energy, a higher efficiency of the energy conversion is possible. The majority of the fusion energy is released as kinetic energy of neutrons, when deuterium reacts with tritium. Fusion reactions such as the D-D reactions, the D-{sup 3}He reaction and the p-{sup 11}B reaction, where a larger part of the fusion energy becomes kinetic energy of charged particles, appears therefore more suitable for direct conversion. Since they have lower reactivity than the D-T reaction, they need a larger {beta}B{sup 2}{sub 0} to give sufficiently high fusion power density. Because of this, the fusion configurations spherical torus (ST) and field-reversed configuration (FRC), where high {beta} values are possible, appear interesting. Rosenbluth and Hinton come to the conclusion that efficient direct conversion isn't possible in closed field line systems and that open geometries, which facilitate direct conversion, provide inadequate confinement for D-{sup 3}He. It is confirmed in this study that it doesn't seem possible to achieve as high direct conversion efficiency in closed systems as in open systems. ST and FRC fusion power plants that utilize direct conversion seem however interesting. Calculations with the help of Maple indicate that the reactor parameters needed for a D-D ST and a D{sub 3} He ST hopefully are possible to achieve. The best energy conversion option for a D-D or D{sub 3} He ST appears to be direct electrodynamic conversion (DEC) together with ordinary thermal conversion

  5. Complex methyl groups dynamics in [(CH3)4P]3Sb2Br9 (PBA) from low to high temperatures by proton spin-lattice relaxation and narrowing of proton NMR spectrum.

    Science.gov (United States)

    Latanowicz, L; Medycki, W; Jakubas, R

    2009-11-01

    Molecular dynamics of a polycrystalline sample of [(CH(3))(4)P](3)Sb(2)Br(9) (PBA) has been studied on the basis of the T(1) (24.7 MHz) relaxation time measurement, the proton second moment of NMR and the earlier published T(1) (90 MHz) relaxation times. The study was performed in a wide range of temperatures (30-337 K). The tunnel splitting omega(T) of the methyl groups was estimated as of low frequency (from kHz to few MHz). The proton spin pairs of the methyl group are known to perform a complex internal motion being a resultant of four components. Three of them involve mass transportation over and through the potential barrier and are characterized by the correlation times tau(3) and tau(T)of the jumps over the barrier and tunnel jumps in the threefold potential of the methyl group and tau(iso) the correlation time of isotropic rotation of the whole TMP cation. For tau(3) and tau(iso) the Arrhenius temperature dependence was assumed, while for tau(T)--the Schrödinger one. The fourth motion causes fluctuations of the tunnel splitting frequency, omega(T), and it is related to the lifetime of the methyl spin at the energy level. The correlation function for this fourth motion (tau(omega) correlation time) has been proposed by Müller-Warmuth et al. In this paper a formula for the correlation function and spectral density of the complex motion made of the above-mentioned four components was derived and used in interpretation of the T(1) relaxation time. The second moment of proton NMR line at temperatures below 50K is four times lower than its value for the rigid structure. The three components of the internal motion characterized by tau(T), tau(H), and tau(iso) were proved to reduce the second moment of the NMR line. The tunnel jumps of the methyl group reduce M(2) at almost 0K, the classical jumps over the barrier reduce M(2) in the vicinity of 50K, while the isotropic motion near 150K. Results of the study on the dynamics of CH(3) groups of TMP cation based on the second moment measurements were correlated with those based on T(1) time measurements.

  6. Directive and Non-Directive Movement in Child Therapy.

    Science.gov (United States)

    Krason, Katarzyna; Szafraniec, Grazyna

    1999-01-01

    Presents a new authorship method of child therapy based on visualization through motion. Maintains that this method stimulates motor development and musical receptiveness, and promotes personality development. Suggests that improvised movement to music facilitates the projection mechanism and that directed movement starts the channeling phase.…

  7. Multi-Directional Environmental Sensors

    Science.gov (United States)

    Manohara, Harish (Inventor); Del Castillo, Linda Y. (Inventor); Mojarradi, Mohammed M. (Inventor)

    2016-01-01

    Systems and methods in accordance with embodiments of the invention implement multi-directional environmental sensors. In one embodiment, a multi-directional environmental sensor includes: an inner conductive element that is substantially symmetrical about three orthogonal planes; an outer conductive element that is substantially symmetrical about three orthogonal planes; and a device that measures the electrical characteristics of the multi-directional environmental sensor, the device having a first terminal and a second terminal; where the inner conductive element is substantially enclosed within the outer conductive element; where the inner conductive element is electrically coupled to the first terminal of the device; and where the outer conductive element is electrically coupled to the second terminal of the device.

  8. Direct Methanol Fuel Cell, DMFC

    Directory of Open Access Journals (Sweden)

    Amornpitoksuk, P.

    2003-09-01

    Full Text Available Direct Methanol Fuel Cell, DMFC is a kind of fuel cell using methanol as a fuel for electric producing. Methanol is low cost chemical substance and it is less harmful than that of hydrogen fuel. From these reasons it can be commercial product. The electrocatalytic reaction of methanol fuel uses Pt-Ru metals as the most efficient catalyst. In addition, the property of membrane and system designation are also effect to the fuel cell efficient. Because of low power of methanol fuel cell therefore, direct methanol fuel cell is proper to use for the energy source of small electrical devices and vehicles etc.

  9. Directional Validation of Wave Predictions

    Science.gov (United States)

    2007-03-01

    motivators: I) the desire to make the problem more solution is simply to use only variables directly Cx- manageable via frequency-wise integration of direc...ViaW()2 + bi(f), where . = j F(f) d. The calculation in reverse is a, = in, cosO , and b, = ni, sinf0 . Note that if we choose f, andf2 as values close...34). The use of a broader band of frequencies makes the metric more stable, but CALCULATION OF MEAN WAVE DIRECTION AND increases the risk that two

  10. Directions for improved fusion reactors

    International Nuclear Information System (INIS)

    Krakowski, R.A.; Miller, R.L.; Delene, J.G.

    1986-01-01

    Conceptual fusion reactor studies over the past 10 to 15 years have projected systems that may be too large, complex, and costly to be of commercial interest. One main direction for improved fusion reactors points towards smaller, higher-power-density approaches. First-order economic issues (i.e., unit direct cost and cost of electricity) are used to support the need for more compact fusion reactors. A generic fusion physics/engineering/costing model is used to provide a quantiative basis for these arguments for specific fusion concepts

  11. PROTOTIPE VIDEO EDITOR DENGAN MENGGUNAKAN DIRECT X DAN DIRECT SHOW

    Directory of Open Access Journals (Sweden)

    Djoni Haryadi Setiabudi

    2004-01-01

    Full Text Available Technology development had given people the chance to capture their memorable moments in video format. A high quality digital video is a result of a good editing process. Which in turn, arise the new need of an editor application. In accordance to the problem, here the process of making a simple application for video editing needs. The application development use the programming techniques often applied in multimedia applications, especially video. First part of the application will begin with the video file compression and decompression, then we'll step into the editing part of the digital video file. Furthermore, the application also equipped with the facilities needed for the editing processes. The application made with Microsoft Visual C++ with DirectX technology, particularly DirectShow. The application provides basic facilities that will help the editing process of a digital video file. The application will produce an AVI format file after the editing process is finished. Through the testing process of this application shows the ability of this application to do the 'cut' and 'insert' of video files in AVI, MPEG, MPG and DAT formats. The 'cut' and 'insert' process only can be done in static order. Further, the aplication also provide the effects facility for transition process in each clip. Lastly, the process of saving the new edited video file in AVI format from the application. Abstract in Bahasa Indonesia : Perkembangan teknologi memberi kesempatan masyarakat untuk mengabadikan saat - saat yang penting menggunakan video. Pembentukan video digital yang baik membutuhkan proses editing yang baik pula. Untuk melakukan proses editing video digital dibutuhkan program editor. Berdasarkan permasalahan diatas maka pada penelitian ini dibuat prototipe editor sederhana untuk video digital. Pembuatan aplikasi memakai teknik pemrograman di bidang multimedia, khususnya video. Perencanaan dalam pembuatan aplikasi tersebut dimulai dengan pembentukan

  12. Verification of the directivity index and other measures of directivity in predicting directional benefit

    Science.gov (United States)

    Dittberner, Andrew; Bentler, Ruth

    2005-09-01

    The relationship between various directivity measures and subject performance with directional microphone hearing aids was determined. Test devices included first- and second-order directional microphones. Recordings of sentences and noise (Hearing in Noise Test, HINT) were made through each test device in simple, complex, and anisotropic background noise conditions. Twenty-six subjects, with normal hearing, were administered the HINT test recordings, and directional benefit was computed. These measures were correlated to theoretical, free-field, and KEMAR DI values, as well as front-to-back ratios, in situ SNRs, and a newly proposed Db-SNR, wherein a predictive value of the SNR improvement is calculated as a function of the noise source incidence. The different predictive scores showed high correlation to the measured directional benefit scores in the complex (diffuse-like) background noise condition (r=0.89-0.97, pThe Db-SNR approach and the in situ SNR measures provided excellent prediction of subject performance in all background noise conditions (0.85-0.97, pthe predictive measures could account for the effects of reverberation on the speech signal (r=0.35-0.40, p<0.05).

  13. Direct-semidirect (DSD) codes

    International Nuclear Information System (INIS)

    Cvelbar, F.

    1999-01-01

    Recent codes for direct-semidirect (DSD) model calculations in the form of answers to a detailed questionnaire are reviewed. These codes include those embodying the classical DSD approach covering only the transitions to the bound states (RAF, HIKARI, and those of the Bologna group), as well as the code CUPIDO++ that also treats transitions to unbound states. (author)

  14. Direct solar-pumped lasers

    Science.gov (United States)

    Lee, J. H.; Shiu, Y. J.; Weaver, W. R.

    1980-01-01

    The feasibility of direct solar pumping of an iodine photodissociation laser at lambda = 1.315 microns was investigated. Threshold inversion density and effect of elevated temperature (up to 670 K) on the laser output were measured. These results and the concentration of solar radiation required for the solar pumped iodine laser are discussed.

  15. Entry: direct control or regulation?

    NARCIS (Netherlands)

    Perotti, E.; Vorage, M.

    2009-01-01

    We model a setting in which citizens form coalitions to seek preferential entry to a given market. The lower entry the higher firm profits and political contributions, but the lower social welfare. Politicians choose to either control entry directly and be illegally bribed, or regulate entry using a

  16. Direct Oral Anticoagulants and Women

    NARCIS (Netherlands)

    Cohen, Hannah; Arachchillage, Deepa R. J.; Beyer-Westendorf, Jan; Middeldorp, Saskia; Kadir, Rezan A.

    2016-01-01

    Direct oral anticoagulants (DOACs) provide an effective, safe, and convenient therapeutic alternative to warfarin and other vitamin K antagonists (VKAs), and are now established for a wide range of indications. The use of DOACs in women merits special consideration due to two main situations: first,

  17. Foreign direct investment in Hungary

    NARCIS (Netherlands)

    Hastenberg, Johannes Josephus Wilhelmus van

    1999-01-01

    Effecten op de modernisering van de industrie en de vraag naar arbeid Na de val van de Berlijnse muur in 1989 en het verdwijnen van het socialisme werd Hongarije een aantrekkelijke bestemming voor buitenlandse directe investeringen (FDI). De combinatie van marktpotentie, lage loonkosten en een

  18. Multi-directional productivity change

    DEFF Research Database (Denmark)

    Asmild, Mette; Balezentis, Tomas; Hougaard, Jens Leth

    2016-01-01

    In this paper we introduce an extension of the Malmquist total factor productivity index, which utilizes the Multi-directional Efficiency Analysis approach. This enables variable-specific analysis of productivity change as well as its components (efficiency change and technical change). The new...

  19. EU citizenship and direct taxation

    NARCIS (Netherlands)

    E.W. Ros (Erik)

    2017-01-01

    markdownabstractThe main question addressed in this study is: _How has the concept of EU citizenship influenced the legal autonomy of Member States; most notably in the field of direct taxation and are the implications of that influence on the tax autonomy of Member States acceptable?_

  20. Guide to Direct Consolidation Loans.

    Science.gov (United States)

    Department of Education, Washington, DC.

    Intended for financial aid counselors, this document provides guidelines to the Federal Direct Consolidation Loan Program for borrowers who are in school, as well as those in repayment, or in default. An introductory section explains the basics of the consolidated loan program, loan categories, and interest rates. Next, standards for borrower…

  1. Directivity of basic linear arrays

    DEFF Research Database (Denmark)

    Bach, Henning

    1970-01-01

    For a linear uniform array ofnelements, an expression is derived for the directivity as a function of the spacing and the phase constants. The cases of isotropic elements, collinear short dipoles, and parallel short dipoles are included. The formula obtained is discussed in some detail and contour...

  2. Directional Dependence in Developmental Research

    Science.gov (United States)

    von Eye, Alexander; DeShon, Richard P.

    2012-01-01

    In this article, we discuss and propose methods that may be of use to determine direction of dependence in non-normally distributed variables. First, it is shown that standard regression analysis is unable to distinguish between explanatory and response variables. Then, skewness and kurtosis are discussed as tools to assess deviation from…

  3. Evolutionary trends in directional hearing

    DEFF Research Database (Denmark)

    Carr, Catherine E; Christensen-Dalsgaard, Jakob

    2016-01-01

    Tympanic hearing is a true evolutionary novelty that arose in parallel within early tetrapods. We propose that in these tetrapods, selection for sound localization in air acted upon pre-existing directionally sensitive brainstem circuits, similar to those in fishes. Auditory circuits in birds...

  4. Electromagnetic direct implicit PIC simulation

    International Nuclear Information System (INIS)

    Langdon, A.B.

    1983-01-01

    Interesting modelling of intense electron flow has been done with implicit particle-in-cell simulation codes. In this report, the direct implicit PIC simulation approach is applied to simulations that include full electromagnetic fields. The resulting algorithm offers advantages relative to moment implicit electromagnetic algorithms and may help in our quest for robust and simpler implicit codes

  5. Time-resolved optically-detected magnetic resonance of II-VI diluted-magnetic-semiconductor heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, V.Yu.; Karczewski, G. [Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland); Godlewski, M. [Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland); Dept. Mathem. and Natural Sci. College of Sci., Card. S. Wyszynski Univ., Warsaw (Poland); Yakovlev, D.R. [Experimental Physics 2, University of Dortmund, 44221 Dortmund (Germany); A. F. Ioffe Physico-Technical Institute, 194017 St. Petersburg (Russian Federation); Ryabchenko, S.M. [Institute of Physics NAS Ukraine, 03028 Kiev (Ukraine); Waag, A. [Institute of Semiconductor Technology, Braunschweig Technical University, 38106 Braunschweig (Germany)

    2007-01-15

    Time-resolved optically-detected magnetic resonance (ODMR) technique was used to study spin dynamics of Mn{sup 2+} ions in (Zn,Mn)Se- and (Cd,Mn)Te-based diluted magnetic semiconductor quantum wells. Times of spin-lattice relaxation have been measured directly from a dynamical shift of exciton luminescence lines after a pulsed impact of 60 GHz microwave radiation. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Breakdown of interdependent directed networks.

    Science.gov (United States)

    Liu, Xueming; Stanley, H Eugene; Gao, Jianxi

    2016-02-02

    Increasing evidence shows that real-world systems interact with one another via dependency connectivities. Failing connectivities are the mechanism behind the breakdown of interacting complex systems, e.g., blackouts caused by the interdependence of power grids and communication networks. Previous research analyzing the robustness of interdependent networks has been limited to undirected networks. However, most real-world networks are directed, their in-degrees and out-degrees may be correlated, and they are often coupled to one another as interdependent directed networks. To understand the breakdown and robustness of interdependent directed networks, we develop a theoretical framework based on generating functions and percolation theory. We find that for interdependent Erdős-Rényi networks the directionality within each network increases their vulnerability and exhibits hybrid phase transitions. We also find that the percolation behavior of interdependent directed scale-free networks with and without degree correlations is so complex that two criteria are needed to quantify and compare their robustness: the percolation threshold and the integrated size of the giant component during an entire attack process. Interestingly, we find that the in-degree and out-degree correlations in each network layer increase the robustness of interdependent degree heterogeneous networks that most real networks are, but decrease the robustness of interdependent networks with homogeneous degree distribution and with strong coupling strengths. Moreover, by applying our theoretical analysis to real interdependent international trade networks, we find that the robustness of these real-world systems increases with the in-degree and out-degree correlations, confirming our theoretical analysis.

  7. Predicting Market Direction from Direct Speech by Business Leaders

    OpenAIRE

    Drury, Brett M.; Almeida, José João

    2012-01-01

    Direct quotations from business leaders can communicate to the wider public the latent state of their organization as well as the beliefs of the organization's leaders. Candid quotes from business leaders can have dramatic effects upon the share price of their organization. For example, Gerald Ratner in 1991 stated that his company's products were crap and consequently his company (Ratners) lost in excess of 500 million pounds in market value. Information in quotes from business leaders can b...

  8. Rejuvenating direct modulation and direct detection for modern optical communications

    Science.gov (United States)

    Che, Di; Li, An; Chen, Xi; Hu, Qian; Shieh, William

    2018-02-01

    High-speed transoceanic optical fiber transmission using direct modulation (DM) and direct detection (DD) was one of the most stirring breakthroughs for telecommunication in 1990s, which drove the internet as a global phenomenon. However, the later evolution of optical coherent communications in 2000s gradually took over the long-haul applications, due to its superior optical spectral efficiency. Nowadays, DM-DD systems are dominant mainly in cost- and power-sensitive short-reach applications, because of its natural characteristics-the simplicity. This paper reviews the recent advances of DM-DD transceivers from both hardware and signal processing perspectives. It introduces a variety of modified DM and/or DD systems for 3 application scenarios: very-short-reach interconnect with little fiber channel impact; single or a few spans of fiber transmission up to several hundred km; and distance beyond the 2nd scenario. Besides the DM-DD and multi-dimension DM-DD with polarization diversity, this paper focuses on how to rejuvenate traditional DM and DD technologies in order to bridge the transmission application gap between DM-DD and coherent transceivers, using technologies such as dispersion compensation, signal field recovery from the intensity-only DD receiver, and complex direct modulation with coherent detection. More than 30 years since the birth, DM and DD still hold indispensable roles in modern optical communications.

  9. Dark matter spin determination with directional direct detection experiments

    Science.gov (United States)

    Catena, Riccardo; Conrad, Jan; Döring, Christian; Ferella, Alfredo Davide; Krauss, Martin B.

    2018-01-01

    If dark matter has spin 0, only two WIMP-nucleon interaction operators can arise as leading operators from the nonrelativistic reduction of renormalizable single-mediator models for dark matter-quark interactions. Based on this crucial observation, we show that about 100 signal events at next generation directional detection experiments can be enough to enable a 2 σ rejection of the spin 0 dark matter hypothesis in favor of alternative hypotheses where the dark matter particle has spin 1 /2 or 1. In this context, directional sensitivity is crucial since anisotropy patterns in the sphere of nuclear recoil directions depend on the spin of the dark matter particle. For comparison, about 100 signal events are expected in a CF4 detector operating at a pressure of 30 torr with an exposure of approximately 26,000 cubic-meter-detector days for WIMPs of 100 GeV mass and a WIMP-fluorine scattering cross section of 0.25 pb. Comparable exposures require an array of cubic meter time projection chamber detectors.

  10. Setting a personal career direction.

    Science.gov (United States)

    McCurdy, Fredrick A; Marcdante, Karen

    2003-01-01

    In summary, we believe that both you and your organization should have a set of core values, a well-defined mission (core purpose), and a vision of the future. Ideally, your projects and activities should be congruent with your mission and values, you should be pursuing your vision, and all of this should be congruent with the organization mission and values. Practically speaking, most individuals we have worked with over the years find themselves in two different groups at this point in the exercise. The minority find that their personal mission is not at all similar to the mission of their current organization and they find it necessary to seriously reevaluate their personal career direction. Sometimes, this results in them finding some other place to work. On the other hand, the majority discover their personal mission is in reasonable agreement with that of their organization. For both, this exercise has helped them clarify and better manage their personal career direction.

  11. Theory of direct interparticle action

    International Nuclear Information System (INIS)

    Vladimirov, Yu.S.; Turygin, A.Yu.

    1986-01-01

    Unusual point of view on the physical picture of the Universe and ratio between main physical categories is considered. Principal moments and theory peculiarities based on the conception of direct interparticle action are underlined. The direct interparticle action theory (DIAT) is considered from the position of choosing one or another axiomatics. At first the Fokker action principle is postulated there and then identical satisfiability of field equations is proved. All that relates to vacuum DIAT ignores and actions of matter formations are used as the basis. DIAT bears up against a global factor-account of absrbers of all surroundings (the Mach principle). The DIAT pretended to relativistic description of only additional concepts with the previously asigned space-time ratios. Concept for construction of the physical picture of the Universe, where classical space-time ratios being of secondary character, is suggested

  12. Sensing roughness and polish direction

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Olesen, Anders Sig; Larsen, Henning Engelbrecht

    2016-01-01

    As a part of the work carried out in a project supported by the Danish Council for Technology and Innovation, we have investigated the option of smoothing standard CNC-machined surfaces. In the process of constructing optical prototypes, involving custom-designed optics, the development cost...... and time consumption can become prohibitive in a research budget. Machining the optical surfaces directly is expensive and time consuming. Alternatively, a more standardized and cheaper machining method can be used, calling for the object to be manually polished. During the polishing process, the operator...... needs information about the RMS-value of the surface roughness and the current direction of the scratches introduced by the polishing process. The RMS-value indicates to the operator how far he is from the final finish, and the scratch orientation is often specified by the customer in order to avoid...

  13. Directed information measures in neuroscience

    CERN Document Server

    Vicente, Raul; Lizier, Joseph

    2014-01-01

    Analysis of information transfer has found rapid adoption in neuroscience, where a highly dynamic transfer of information continuously runs on top of the brain's slowly-changing anatomical connectivity. Measuring such transfer is crucial to understanding how flexible information routing and processing give rise to higher cognitive function. Directed Information Measures in Neuroscience reviews recent developments of concepts and tools for measuring information transfer, their application to neurophysiological recordings and analysis of interactions. Written by the most active researchers in the field the book discusses the state of the art, future prospects and challenges on the way to an efficient assessment of neuronal information transfer. Highlights include the theoretical quantification and practical estimation of information transfer, description of transfer locally in space and time, multivariate directed measures, information decomposition among a set of stimulus/responses variables, and the relation ...

  14. Future directions for nursing administration.

    Science.gov (United States)

    Poulin, M A

    1984-03-01

    As the age of centralization wanes, nurse executives must look ahead. The author, noting a terrain obscured by the increasing complexity of nursing practice, points out the advantages of decentralizing decision making and of providing a distinctive nursing stamp to research and administration theory. Nurse executives, trained in management from early in their professional formation, can provide enlightened direction and flexible support for tomorrow's opportunities.

  15. Direct search for dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jonghee; /Fermilab

    2009-12-01

    Dark matter is hypothetical matter which does not interact with electromagnetic radiation. The existence of dark matter is only inferred from gravitational effects of astrophysical observations to explain the missing mass component of the Universe. Weakly Interacting Massive Particles are currently the most popular candidate to explain the missing mass component. I review the current status of experimental searches of dark matter through direct detection using terrestrial detectors.

  16. Effects of Directed Energy Weapons

    Science.gov (United States)

    1994-01-01

    S. Feld, Ronald E. McNair, and Stephen R. Wilk, “The Physics of Karate,” Scientific American 240, 150 (April, 1979). 103. See Kittel (note 18...References 1. Figure 4–1 was adapted from Stephen Cheung and Frederic H. Levien, Microwaves Made Simple: Principles and Applications. (Dedham, MA: Artech...Physics (New York: MC- Graw Hill, 1965). Effects of Directed Energy Weapons 258 16. The physical meaning of this integral is that the propagation path

  17. Dimensional crossover in directed percolation

    International Nuclear Information System (INIS)

    Chame, A.M.N.; Queiroz, S.L.A. de; Santos, Raimundo R. dos.

    1984-04-01

    We study the dimensional crossover in directed percolation in three dimensions. Bonds are allowed to have different concentrations along the three cartesian axes of the lattice. Through a Position Space Renormalization Group we obtain the phase-diagrama where non-percolating, 1-D, 2-D and 3-D percolating phases are present. We find that the isotropic fixed points are unstable with respect to anisotropy, thus driving the system into a different universality class. (author) [pt

  18. Medium effects in direct reactions

    International Nuclear Information System (INIS)

    Karakoc, M; Bertulani, C

    2013-01-01

    We discuss medium corrections of the nucleon-nucleon (NN) cross sections and their influence on direct reactions at intermediate energies ≳50 MeV/nucleon. The results obtained with free NN cross sections are compared with those obtained with a geometrical treatment of Pauli-blocking and Dirac-Bruecker methods. We show that medium corrections may lead to sizable modifications for collisions at intermediate energies and that they are more pronounced in reactions involving weakly bound nuclei.

  19. Directed Innovation of Business Models

    OpenAIRE

    Stelian Brad; Emilia Brad

    2016-01-01

    Business model innovation is an important issue to keep business competitive and increase company’s profits. Due to many market attractors, identification of appropriate paths of business model evolution is a painful and risky process. To improve decision’s effectiveness in this process, an architectural construct of analysis and conceptualization for business model innovation that combines directed evolution and blue ocean concepts is proposed in this paper under the name o...

  20. Direction of Heavy Water Projects

    International Nuclear Information System (INIS)

    1984-07-01

    Summary of the activities performed by the Heavy Water Projects Direction of the Argentine Atomic Energy Commission from 1950 to 1983. It covers: historical data; industrial plant (based on ammonia-hydrogen isotopic exchange); experimental plant (utilizing hydrogen sulfides-water process); Module-80 plant (2-3 tons per year experimental plant with national technology) and other related tasks on research and development (E.A.C.) [es

  1. Directional dependency of air sampling

    International Nuclear Information System (INIS)

    1994-01-01

    A field study was performed by Idaho State University-Environmental Monitoring Laboratory (EML) to examine the directional dependency of low-volume air samplers. A typical continuous low volume air sampler contains a sample head that is mounted on the sampler housing either horizontally through one of four walls or vertically on an exterior wall 'looking down or up.' In 1992, a field study was undertaken to estimate sampling error and to detect the directional effect of sampler head orientation. Approximately 1/2 mile downwind from a phosphate plant (continuous source of alpha activity), four samplers were positioned in identical orientation alongside one sampler configured with the sample head 'looking down'. At least five consecutive weekly samples were collected. The alpha activity, beta activity, and the Be-7 activity collected on the particulate filter were analyzed to determine sampling error. Four sample heads were than oriented to the four different horizontal directions. Samples were collected for at least five weeks. Analysis of the alpha data can show the effect of sampler orientation to a know near source term. Analysis of the beta and Be-7 activity shows the effect of sampler orientation to a ubiquitous source term

  2. Direct detection with dark mediators

    Energy Technology Data Exchange (ETDEWEB)

    Curtin, David; Surujon, Ze' ev [C. N. Yang Institute for Theoretical Physics, Stony Brook University, Stony Brook, NY 11794 (United States); Tsai, Yuhsin [Physics Department, University of California Davis, Davis, CA 95616 (United States)

    2014-11-10

    We introduce dark mediator Dark Matter (dmDM) where the dark and visible sectors are connected by at least one light mediator ϕ carrying the same dark charge that stabilizes DM. ϕ is coupled to the Standard Model via an operator q{sup ¯}qϕϕ{sup ⁎}/Λ, and to dark matter via a Yukawa coupling y{sub χ}χ{sup c¯}χϕ. Direct detection is realized as the 2→3 process χN→χ{sup ¯}Nϕ at tree-level for m{sub ϕ}≲10 keV and small Yukawa coupling, or alternatively as a loop-induced 2→2 process χN→χN. We explore the direct-detection consequences of this scenario and find that a heavy O(100 GeV) dmDM candidate fakes different O(10 GeV) standard WIMPs in different experiments. Large portions of the dmDM parameter space are detectable above the irreducible neutrino background and not yet excluded by any bounds. Interestingly, for the m{sub ϕ} range leading to novel direct detection phenomenology, dmDM is also a form of Self-Interacting Dark Matter (SIDM), which resolves inconsistencies between dwarf galaxy observations and numerical simulations.

  3. BNL Direct Wind Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A.; Muratore, A.; Wanderer, P.

    2011-09-12

    BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.

  4. Directional Darwinian Selection in proteins.

    Science.gov (United States)

    McClellan, David A

    2013-01-01

    Molecular evolution is a very active field of research, with several complementary approaches, including dN/dS, HON90, MM01, and others. Each has documented strengths and weaknesses, and no one approach provides a clear picture of how natural selection works at the molecular level. The purpose of this work is to present a simple new method that uses quantitative amino acid properties to identify and characterize directional selection in proteins. Inferred amino acid replacements are viewed through the prism of a single physicochemical property to determine the amount and direction of change caused by each replacement. This allows the calculation of the probability that the mean change in the single property associated with the amino acid replacements is equal to zero (H0: μ = 0; i.e., no net change) using a simple two-tailed t-test. Example data from calanoid and cyclopoid copepod cytochrome oxidase subunit I sequence pairs are presented to demonstrate how directional selection may be linked to major shifts in adaptive zones, and that convergent evolution at the whole organism level may be the result of convergent protein adaptations. Rather than replace previous methods, this new method further complements existing methods to provide a holistic glimpse of how natural selection shapes protein structure and function over evolutionary time.

  5. Direct reciprocity in structured populations.

    Science.gov (United States)

    van Veelen, Matthijs; García, Julián; Rand, David G; Nowak, Martin A

    2012-06-19

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that "indirect invasions" remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies.

  6. Alternating spin chain compound AgVOAsO4 probed by 75As NMR

    Science.gov (United States)

    Ahmed, N.; Khuntia, P.; Ranjith, K. M.; Rosner, H.; Baenitz, M.; Tsirlin, A. A.; Nath, R.

    2017-12-01

    75As NMR measurements were performed on a polycrystalline sample of spin-1/2 alternating spin chain Heisenberg antiferromagnet AgVOAsO4. The temperature-dependent NMR shift K (T ) , which is a direct measure of the intrinsic spin susceptibility, agrees very well with the spin-1/2 alternating-chain model, justifying the assignment of the spin lattice. From the analysis of K (T ) , magnetic exchange parameters were estimated as follows: the leading exchange J /kB≃38.4 K and the alternation ratio α =J'/J ≃0.69 . The transferred hyperfine coupling between the 75As nucleus and V4 + spins obtained by comparing the NMR shift with the bulk susceptibility amounts to Ahf≃3.3 TμB. The effect of interchain couplings on the low-temperature activated behavior of K (T ) and the spin-lattice relaxation rate 1 /T1 is identified.

  7. Direct utilization of geothermal energy

    International Nuclear Information System (INIS)

    Lund, J. W.

    2010-01-01

    The worldwide application of geothermal energy for direct utilization is reviewed. This paper is based on the world update for direct-use presented at the World Geothermal Congress 2010 in Bali, Indonesia (WGC2010) which also includes material presented at three world geothermal congresses in Italy, Japan and Turkey (WGC95, WGC2000 and WGC2005). This report is based on country update papers prepared for WGC2010 and data from other sources. Final update papers were received from 70 countries of which 66 reported some direct utilization of geothermal energy for WGC2010. Twelve additional countries were added to the list based on other sources of information. The 78 countries having direct utilization of geothermal energy, is a significant increase from the 72 reported in 2005, the 58 reported in 2000, and the 28 reported in 1995. An estimate of the installed thermal power for direct utilization at the end of 2009, reported from WGC2010 is 48,493 MW th , almost a 72 % increased over the 2005 data, growing at a compound rate of 11.4% annually with a capacity factor of 0.28. The thermal energy used is 423,830 TJ/year (117,740 GWh/yr), about a 55% increase over 2005, growing at a compound rate of 9.2% annually. The distribution of thermal energy used by category is approximately 47.2% for ground-source heat pumps, 25.8% for bathing and swimming (including balneology), 14.9% for space heating (of which 85% is for district heating), 5.5% for greenhouses and open ground heating, 2.8% for industrial process heating, 2.7% for aquaculture pond and raceway heating, 0.4% for agricultural drying, 0.5% for snow melting and cooling, and 0.2% for other uses. Energy savings amounted to 250 million barrels (38 million tonnes) of equivalent oil annually, preventing 33 million tonnes of carbon and 107 million tonnes of CO 2 being released to the atmosphere which includes savings in geothermal heat pump cooling (compared to using fuel oil to generate electricity). (author)

  8. Direct Utilization of Geothermal Energy

    Directory of Open Access Journals (Sweden)

    John W. Lund

    2010-08-01

    Full Text Available The worldwide application of geothermal energy for direct utilization is reviewed. This paper is based on the world update for direct-use presented at the World Geothermal Congress 2010 in Bali, Indonesia (WGC2010 [1] which also includes material presented at three world geothermal congresses in Italy, Japan and Turkey (WGC95, WGC2000 and WGC2005. This report is based on country update papers prepared for WGC2010 and data from other sources. Final update papers were received from 70 countries of which 66 reported some direct utilization of geothermal energy for WGC2010. Twelve additional countries were added to the list based on other sources of information. The 78 countries having direct utilization of geothermal energy, is a significant increase from the 72 reported in 2005, the 58 reported in 2000, and the 28 reported in 1995. An estimate of the installed thermal power for direct utilization at the end of 2009, reported from WGC2010 is 48,493 MWt, almost a 72 % increased over the 2005 data, growing at a compound rate of 11.4% annually with a capacity factor of 0.28. The thermal energy used is 423,830 TJ/year (117,740 GWh/yr, about a 55% increase over 2005, growing at a compound rate of 9.2% annually. The distribution of thermal energy used by category is approximately 47.2% for ground-source heat pumps, 25.8% for bathing and swimming (including balneology, 14.9% for space heating (of which 85% is for district heating, 5.5% for greenhouses and open ground heating, 2.8% for industrial process heating, 2.7% for aquaculture pond and raceway heating, 0.4% for agricultural drying, 0.5% for snow melting and cooling, and 0.2% for other uses. Energy savings amounted to 250 million barrels (38 million tonnes of equivalent oil annually, preventing 33 million tonnes of carbon and 107 million tonnes of CO2 being release to the atmosphere which includes savings in geothermal heat pump cooling (compared to using fuel oil to generate electricity.

  9. Entrance Counseling Guide for Direct Loan Borrowers

    Science.gov (United States)

    Federal Student Aid, US Department of Education, 2010

    2010-01-01

    This guide describes the four types of loans offered by the Direct Loan Program[SM]: (1) Direct Subsidized Loans; (2) Direct Unsubsidized Loans; (3) Direct PLUS Loans; and (4) Direct Consolidation Loans. Among the topics covered in the guide are: Use of Your Loan Money, The Master Promissory Note, How Your Loans Will Be Disbursed (Paid Out),…

  10. Current directions in radiopharmaceutical research

    Energy Technology Data Exchange (ETDEWEB)

    Mather, S J [Department of Nuclear Medicine, St. Bartholomew` s Hospital, London (United Kingdom)

    1998-08-01

    Much of current radiopharmaceutical research is directed towards the development of receptor-binding tracers which are targeted towards biochemical processes. These may be extra or intracellular in nature and hold promise for an imaging approach to tissue characterisation in-vivo. Many of these products are based on proteins which range in size from large monoclonal antibodies to small neuropeptides and share a radiolabelling chemistry based on the use of bifunctional chelating agents. Although developed initially for use with indium-111, considerations of cost and isotope availability have continued to direct the efforts of many researchers towards the use of technetium-99m. While polypeptide-based radiopharmaceuticals may be useful for imaging peripheral cell-surface receptors, access to sites of interest within the cell, or in the brain, requires the development of small lipophilic molecules with retained ability to interact with intracellular targets. The design and synthesis of these compounds presents a particular challenge to the radiopharmaceutical chemist which is being met through either a pendant or integrated approach to the use of technetium coordination with particular emphasis on technetium (v) cores. Progress continues to be made in the application of targeted radionuclide therapy particularly in the development of radiopharmaceuticals for the treatment of malignant bone disease. methods for labelling antibodies with a great variety of cytotoxic radionuclides have now been refined and their use for radioimmunotherapy in the treatment of haematological malignancies shows great promise. The major medical areas for application of these new radiopharmaceuticals will be in oncology, neurology and inflammation but the increasingly difficult regulatory climate in which drug development and health-care now operate will make it essential for researchers to direct their products toward specific clinical problems as well as biological targets. (author) 36 refs

  11. Direct mediation, duality and unification

    International Nuclear Information System (INIS)

    Abel, Steven; Khoze, Valentin V.

    2008-01-01

    It is well-known that in scenarios with direct gauge mediation of supersymmetry breaking the messenger fields significantly affect the running of Standard Model couplings and introduce Landau poles which are difficult to avoid. Among other things, this appears to remove any possibility of a meaningful unification prediction and is often viewed as a strong argument against direct mediation. We propose two ways that Seiberg duality can circumvent this problem. In the first, which we call 'deflected-unification', the SUSY-breaking hidden sector is a magnetic theory which undergoes a Seiberg duality to an electric phase. Importantly, the electric version has fewer fundamental degrees of freedom coupled to the MSSM compared to the magnetic formulation. This changes the β-functions of the MSSM gauge couplings so as to push their Landau poles above the unification scale. We show that this scenario is realised for recently suggested models of gauge mediation based on a metastable SCQD-type hidden sector directly coupled to MSSM. The second possibility for avoiding Landau poles, which we call 'dual-unification', begins with the observation that, if the mediating fields fall into complete SU(5) multiplets, then the MSSM+messengers exhibits a fake unification at unphysical values of the gauge couplings. We show that, in known examples of electric/magnetic duals, such a fake unification in the magnetic theory reflects a real unification in the electric theory. We therefore propose that the Standard Model could itself be a magnetic dual of some unknown electric theory in which the true unification takes place. This scenario maintains the unification prediction (and unification scale) even in the presence of Landau poles in the magnetic theory below the GUT scale. We further note that this dual realization of grand unification can explain why Nature appears to unify, but the proton does not decay.

  12. Current directions in radiopharmaceutical research

    International Nuclear Information System (INIS)

    Mather, S.J.

    1998-01-01

    Much of current radiopharmaceutical research is directed towards the development of receptor-binding tracers which are targeted towards biochemical processes. These may be extra or intracellular in nature and hold promise for an imaging approach to tissue characterisation in-vivo. Many of these products are based on proteins which range in size from large monoclonal antibodies to small neuropeptides and share a radiolabelling chemistry based on the use of bifunctional chelating agents. Although developed initially for use with indium-111, considerations of cost and isotope availability have continued to direct the efforts of many researchers towards the use of technetium-99m. While polypeptide-based radiopharmaceuticals may be useful for imaging peripheral cell-surface receptors, access to sites of interest within the cell, or in the brain, requires the development of small lipophilic molecules with retained ability to interact with intracellular targets. The design and synthesis of these compounds presents a particular challenge to the radiopharmaceutical chemist which is being met through either a pendant or integrated approach to the use of technetium coordination with particular emphasis on technetium (v) cores. Progress continues to be made in the application of targeted radionuclide therapy particularly in the development of radiopharmaceuticals for the treatment of malignant bone disease. methods for labelling antibodies with a great variety of cytotoxic radionuclides have now been refined and their use for radioimmunotherapy in the treatment of haematological malignancies shows great promise. The major medical areas for application of these new radiopharmaceuticals will be in oncology, neurology and inflammation but the increasingly difficult regulatory climate in which drug development and health-care now operate will make it essential for researchers to direct their products toward specific clinical problems as well as biological targets. (author)

  13. Heading in the right direction

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Ashok

    2011-01-15

    Statoil has developed a new directional technology which optimizes well positioning for unconsolidated geological formations, which addresses a crucial part for the implementation of a steam assisted gravity drainage (SAGD) program. This technology includes a rotary steerable system which, combined with an ultra-deep resistivity sensor, provides precise geosteering resulting therefore in in better well reservoir capture and characterization. Using this technique increases drilling efficiency, thus reducing the drilling time. The company's strategy is to provide cutting edge development to the oil sector and they have created a new research center in Calgary.

  14. Accurate determination of antenna directivity

    DEFF Research Database (Denmark)

    Dich, Mikael

    1997-01-01

    The derivation of a formula for accurate estimation of the total radiated power from a transmitting antenna for which the radiated power density is known in a finite number of points on the far-field sphere is presented. The main application of the formula is determination of directivity from power......-pattern measurements. The derivation is based on the theory of spherical wave expansion of electromagnetic fields, which also establishes a simple criterion for the required number of samples of the power density. An array antenna consisting of Hertzian dipoles is used to test the accuracy and rate of convergence...

  15. Direct synthesis of organic silicates

    International Nuclear Information System (INIS)

    Gismalla, Hana Hassan

    2000-06-01

    Tetraethoxysilane was prepared using the direct synthetic procedure in presence of magnesium ethoxide, tin tetrachloride and tin oxide as catalysts. Magnesium ethoxide was prepared firstly, identified by spectral analysis and then used in the preparation of tetraethoxysilane. The method adopted is reliable and significant as far as synthetic routes are concerned. The product obtained was analysed using infra-red spectroscopy and gas-liquid chromatography, these indicated that the final reaction product can be obtained in high yield and purity. Spectral analysis obtained are in good agreement with reported data for tetraethoxysilane. (Author)

  16. Boltzmann, Darwin and Directionality theory

    Energy Technology Data Exchange (ETDEWEB)

    Demetrius, Lloyd A., E-mail: ldemetr@oeb.harvard.edu

    2013-09-01

    Boltzmann’s statistical thermodynamics is a mathematical theory which relates the macroscopic properties of aggregates of interacting molecules with the laws of their interaction. The theory is based on the concept thermodynamic entropy, a statistical measure of the extent to which energy is spread throughout macroscopic matter. Macroscopic evolution of material aggregates is quantitatively explained in terms of the principle: Thermodynamic entropy increases as the composition of the aggregate changes under molecular collision. Darwin’s theory of evolution is a qualitative theory of the origin of species and the adaptation of populations to their environment. A central concept in the theory is fitness, a qualitative measure of the capacity of an organism to contribute to the ancestry of future generations. Macroscopic evolution of populations of living organisms can be qualitatively explained in terms of a neo-Darwinian principle: Fitness increases as the composition of the population changes under variation and natural selection. Directionality theory is a quantitative model of the Darwinian argument of evolution by variation and selection. This mathematical theory is based on the concept evolutionary entropy, a statistical measure which describes the rate at which an organism appropriates energy from the environment and reinvests this energy into survivorship and reproduction. According to directionality theory, microevolutionary dynamics, that is evolution by mutation and natural selection, can be quantitatively explained in terms of a directionality principle: Evolutionary entropy increases when the resources are diverse and of constant abundance; but decreases when the resource is singular and of variable abundance. This report reviews the analytical and empirical support for directionality theory, and invokes the microevolutionary dynamics of variation and selection to delineate the principles which govern macroevolutionary dynamics of speciation and

  17. The Strength of Direct Ties

    DEFF Research Database (Denmark)

    Claussen, Jörg; Falck, Oliver; Grosjean, Thorsten

    2012-01-01

    We analyze the economic effects of a developer's connectedness in the electronic game industry. Knowledge spillovers between developers are likely to be of special relevance in this knowledge-intensive and regionally concentrated industry. We calculate social network measures for a developer......'s connectedness to other developers at multiple points in time. In a regression in which we exploit within-career variation in social network measures, we find that the number of direct ties a developer has to other developers has a strong effect on both a game's revenues and critics' scores. The quality...... of indirect ties makes no additional contribution to the game's success....

  18. Direct Chlorination of Zircon Sand

    International Nuclear Information System (INIS)

    Dwiretnani Sudjoko; Budi Sulistyo; Pristi Hartati; Sunardjo

    2002-01-01

    It was investigated the direct chlorination of zircon sand in a unit chlorination equipment. The process was in semi batch. The product gas was scrubbed in aqueous NaOH. It was search the influence of time, ratio of reactant and size of particle sand to the concentration of Zr and Si in the product. From these research it was found that as the times, ratio of reactant increased, the concentration of Zr increased, but the concentration of Si decreased, while as grain size of zircon sand decreased the concentration of Zr decreased, but the concentration of Si increased. (author)

  19. Directed Assembly of Gold Nanoparticles

    DEFF Research Database (Denmark)

    Westerlund, Axel Rune Fredrik; Bjørnholm, Thomas

    2009-01-01

    As a complement to common "top-down" lithography techniques, "bottom-up" assembly techniques are emerging as promising tools to build nanoscale structures in a predictable way. Gold nanoparticles that are stable and relatively easy to synthesize are important building blocks in many such structures...... due to their useful optical and electronic properties. Programmed assembly of gold nanoparticles in one, two, and three dimensions is therefore of large interest. This review focuses on the progress from the last three years in the field of directed gold nanoparticle and nanorod assembly using...

  20. Directional synthetic aperture flow imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Nikolov, Svetoslav

    2004-01-01

    emissions using a number of defocused elements and a linear frequency modulated pulse (chirp) to improve the signal-to-noise ratio. The received signals are dynamically focused along the flow direction and these signals are used in a cross-correlation estimator for finding the velocity magnitude. The flow...... elements in each emission. A 20 us chirp was used during emission. The RF data were subsequently beamformed off-line and stationary echo canceling was performed. The 60 degrees flow with a peak velocity of 0.15 m/s was determined using 16 groups of 8 emissions and the relative standard deviation was 0...

  1. Boltzmann, Darwin and Directionality theory

    International Nuclear Information System (INIS)

    Demetrius, Lloyd A.

    2013-01-01

    Boltzmann’s statistical thermodynamics is a mathematical theory which relates the macroscopic properties of aggregates of interacting molecules with the laws of their interaction. The theory is based on the concept thermodynamic entropy, a statistical measure of the extent to which energy is spread throughout macroscopic matter. Macroscopic evolution of material aggregates is quantitatively explained in terms of the principle: Thermodynamic entropy increases as the composition of the aggregate changes under molecular collision. Darwin’s theory of evolution is a qualitative theory of the origin of species and the adaptation of populations to their environment. A central concept in the theory is fitness, a qualitative measure of the capacity of an organism to contribute to the ancestry of future generations. Macroscopic evolution of populations of living organisms can be qualitatively explained in terms of a neo-Darwinian principle: Fitness increases as the composition of the population changes under variation and natural selection. Directionality theory is a quantitative model of the Darwinian argument of evolution by variation and selection. This mathematical theory is based on the concept evolutionary entropy, a statistical measure which describes the rate at which an organism appropriates energy from the environment and reinvests this energy into survivorship and reproduction. According to directionality theory, microevolutionary dynamics, that is evolution by mutation and natural selection, can be quantitatively explained in terms of a directionality principle: Evolutionary entropy increases when the resources are diverse and of constant abundance; but decreases when the resource is singular and of variable abundance. This report reviews the analytical and empirical support for directionality theory, and invokes the microevolutionary dynamics of variation and selection to delineate the principles which govern macroevolutionary dynamics of speciation and

  2. Direct application of geothermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Reistad, G.M.

    1980-01-01

    An overall treatment of direct geothermal applications is presented with an emphasis on the above-ground engineering. The types of geothermal resources and their general extent in the US are described. The potential market that may be served with geothermal energy is considered briefly. The evaluation considerations, special design aspects, and application approaches for geothermal energy use in each of the applications are considered. The present applications in the US are summarized and a bibliography of recent studies and applications is provided. (MHR)

  3. Directional dependence of binaural loudness

    DEFF Research Database (Denmark)

    Ellermeier, Wolfgang; Sivonen, Ville Pekka

    2006-01-01

    on binaural loudness summation, on the other hand, focuses on a highly artificial paradigm according to which unnatural combinations of sound pressure levels(such as monotic-diotic comparisons) are presented to listeners via headphones. In order to reconcile these two approaches, we recently started a series...... incidence angle, in order to relate the changes in actual at-ear exposure to the observed changes in loudness as a function of sound incidence. Combining the listening-test data with the physical measurements, an attempt was made to model the binaural summation underlying the directional loudness matches....

  4. A perspective on direct conversion

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, W. B.

    1963-10-15

    As flowing energy, electricity is sought for its versatility. Its generation from some other flow or release of energy without mechanical power, or even sometimes heat, as intermediary is called direct conversion. The objective is high electrical output for minimum total cost and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (author)

  5. Direct Bonded Pontic (Laporan Kasus

    Directory of Open Access Journals (Sweden)

    Suhandi Sidjaja

    2015-10-01

    Full Text Available Advanced science and technology in dentistry enable dental practitioners to modified she bonding techniques in tooth replacement. A pontic made of composite resin bonded to etched enamel of the adjacent teeth can be used in the replacement of one missing anterior tooth with a virgin or sowed adpicent tooth. The advantages of this technique include a one visit treatment, cow cost, good esthetics, less side effects and easy repair or rebounding. Clinical evaluation showed a high success rate therefore with a proper diagnosis and a perfect skill of the direct bonded technique this treatment can be used as an alternative restoration.

  6. Direct measurements of neutrino masses

    Energy Technology Data Exchange (ETDEWEB)

    Holzschuh, E [Zurich Univ. (Switzerland). Inst. fuer Physik

    1996-11-01

    The direct measurements have so far given no indication for a nonzero (positive) mass of any of the three known neutrinos. The experiments measuring the tau and the muon neutrino are good shape. The tritium experiments are in an unfortunate situation. It is unclear to me whether the problems are experimental or theoretical or a combination of both. The electronic final states distribution have been calculated, but the results have never been tested experimentally. The most important question to be answered is about the validity of the sudden approximation. (author) 9 figs., 2 tabs., 16 refs.

  7. Studies of direct electroinsulating enamels

    International Nuclear Information System (INIS)

    Siwulski, S.; Gruszka, B.; Nocun, M.

    1998-01-01

    The results of studies on the influence of chemical composition of direct electroinsulating enamel on its properties were presented. The influence of alkaline Li 2 O, Na 2 O, K 2 O and adhesion promoting oxides CoO, NiO, CuO, MoO 3 on the frits properties were estimated. The characteristic temperature T g and T m as well as flowability were measured. The dielectric properties of frits and prepared enamels were also measured. Enamel substrates were prepared and tested for application in thick hybrid circuit technology. (author)

  8. A perspective on direct conversion

    International Nuclear Information System (INIS)

    Lewis, W.B.

    1963-10-01

    As flowing energy, electricity is sought for its versatility. Its generation from some other flow or release of energy without mechanical power, or even sometimes heat, as intermediary is called direct conversion. The objective is high electrical output for minimum total cost and not always high conversion efficiency. The wide range of techniques embracing cryogenics and hot plasma derives from the special requirements of source, environment and application. Sources include solar and other radiation, nuclear fission and fusion, chemical energy and heat. Environments and applications range from space vehicles to submarines and from giant power networks to isolated buoys and pocket devices. (author)

  9. Direct, rapid RNA sequence analysis

    International Nuclear Information System (INIS)

    Peattie, D.A.

    1987-01-01

    The original methods of RNA sequence analysis were based on enzymatic production and chromatographic separation of overlapping oligonucleotide fragments from within an RNA molecule followed by identification of the mononucleotides comprising the oligomer. Over the past decade the field of nucleic acid sequencing has changed dramatically, however, and RNA molecules now can be sequenced in a variety of more streamlined fashions. Most of the more recent advances in RNA sequencing have involved one-dimensional electrophoretic separation of 32 P-end-labeled oligoribonucleotides on polyacrylamide gels. In this chapter the author discusses two of these methods for determining the nucleotide sequences of RNA molecules rapidly: the chemical method and the enzymatic method. Both methods are direct and degradative, i.e., they rely on fragmatic and chemical approaches should be utilized. The single-strand-specific ribonucleases (A, T 1 , T 2 , and S 1 ) provide an efficient means to locate double-helical regions rapidly, and the chemical reactions provide a means to determine the RNA sequence within these regions. In addition, the chemical reactions allow one to assign interactions to specific atoms and to distinguish secondary interactions from tertiary ones. If the RNA molecule is small enough to be sequenced directly by the enzymatic or chemical method, the probing reactions can be done easily at the same time as sequencing reactions

  10. Direct methods in protein crystallography.

    Science.gov (United States)

    Karle, J

    1989-11-01

    It is pointed out that the 'direct methods' of phase determination for small-structure crystallography do not have immediate applicability to macromolecular structures. The term 'direct methods in macromolecular crystallography' is suggested to categorize a spectrum of approaches to macromolecular structure determination in which the analyses are characterized by the use of two-phase and higher-order-phase invariants. The evaluation of the invariants is generally obtained by the use of heavy-atom techniques. The results of a number of the more recent algebraic and probabilistic studies involving isomorphous replacement and anomalous dispersion thus become valid subjects for discussion here. These studies are described and suggestions are also presented concerning future applicability. Additional discussion concerns the special techniques of filtering, the use of non-crystallographic symmetry, some features of maximum entropy and attempts to apply phase-determining formulas to the refinement of macromolecular structure. It is noted that, in addition to the continuing remarkable progress in macromolecular crystallography based on the traditional applications of isomorphous replacement and anomalous dispersion, recent valuable advances have been made in the application of non-crystallographic symmetry, in particular, to virus structures and in applications of filtering. Good progress has also been reported in the application of exact linear algebra to multiple-wavelength anomalous-dispersion investigations of structures containing anomalous scatterers of only moderate scattering power.

  11. Broadband direct RF digitization receivers

    CERN Document Server

    Jamin, Olivier

    2014-01-01

    This book discusses the trade-offs involved in designing direct RF digitization receivers for the radio frequency and digital signal processing domains.  A system-level framework is developed, quantifying the relevant impairments of the signal processing chain, through a comprehensive system-level analysis.  Special focus is given to noise analysis (thermal noise, quantization noise, saturation noise, signal-dependent noise), broadband non-linear distortion analysis, including the impact of the sampling strategy (low-pass, band-pass), analysis of time-interleaved ADC channel mismatches, sampling clock purity and digital channel selection. The system-level framework described is applied to the design of a cable multi-channel RF direct digitization receiver. An optimum RF signal conditioning, and some algorithms (automatic gain control loop, RF front-end amplitude equalization control loop) are used to relax the requirements of a 2.7GHz 11-bit ADC. A two-chip implementation is presented, using BiCMOS and 65nm...

  12. Radial lean direct injection burner

    Science.gov (United States)

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  13. Direct dating of human fossils.

    Science.gov (United States)

    Grün, Rainer

    2006-01-01

    The methods that can be used for the direct dating of human remains comprise of radiocarbon, U-series, electron spin resonance (ESR), and amino acid racemization (AAR). This review gives an introduction to these methods in the context of dating human bones and teeth. Recent advances in ultrafiltration techniques have expanded the dating range of radiocarbon. It now seems feasible to reliably date bones up to 55,000 years. New developments in laser ablation mass spectrometry permit the in situ analysis of U-series isotopes, thus providing a rapid and virtually non-destructive dating method back to about 300,000 years. This is of particular importance when used in conjunction with non-destructive ESR analysis. New approaches in AAR analysis may lead to a renaissance of this method. The potential and present limitations of these direct dating techniques are discussed for sites relevant to the reconstruction of modern human evolution, including Florisbad, Border Cave, Tabun, Skhul, Qafzeh, Vindija, Banyoles, and Lake Mungo. (c) 2006 Wiley-Liss, Inc.

  14. Plasma dark matter direct detection

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, J.D.; Foot, R., E-mail: j.clarke5@pgrad.unimelb.edu.au, E-mail: rfoot@unimelb.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, Victoria 3010 Australia (Australia)

    2016-01-01

    Dark matter in spiral galaxies like the Milky Way may take the form of a dark plasma. Hidden sector dark matter charged under an unbroken U(1)' gauge interaction provides a simple and well defined particle physics model realising this possibility. The assumed U(1)' neutrality of the Universe then implies (at least) two oppositely charged dark matter components with self-interactions mediated via a massless 'dark photon' (the U(1)' gauge boson). In addition to nuclear recoils such dark matter can give rise to keV electron recoils in direct detection experiments. In this context, the detailed physical properties of the dark matter plasma interacting with the Earth is required. This is a complex system, which is here modelled as a fluid governed by the magnetohydrodynamic equations. These equations are numerically solved for some illustrative examples, and implications for direct detection experiments discussed. In particular, the analysis presented here leaves open the intriguing possibility that the DAMA annual modulation signal is due primarily to electron recoils (or even a combination of electron recoils and nuclear recoils). The importance of diurnal modulation (in addition to annual modulation) as a means of probing this kind of dark matter is also emphasised.

  15. Multi-step direct reactions

    International Nuclear Information System (INIS)

    Koning, A.J.

    1992-07-01

    In recent years a variety of statistical theories has been developed concerning multistep direct (MSD) nuclear reactions. In addition, dominant in applications is a whole class of semiclassical models that may be subsumed under the heading of 'generalized exciton models'; these are basically MSD-type extensions on top of compound-like concepts. In this report the relation between their underlying statistical MSD-postulates are highlighted. A command framework is sketched that enables to generate the various MSD theories through assigning statistical properties to different parts of the nuclear Hamiltonian. Then it is shown that distinct forms of nuclear randomness are embodied in the mentioned theories. All these theories appear to be very similar at a qualitative level. In order to explain the high energy-tails and forward-peaked angular distribution typical for particles emitted in MSD reactions, it is imagined that the incident continuum particle stepwise looses its energy and direction in a sequence of collisions, thereby creating new particle-hole pairs in the target system. At each step emission may take place. The statistical aspect comes in because many continuum states are involved in the process. These are supposed to display chaotic behavior, the associated randomness assumption giving rise to important simplifications in the expression for MSD emission cross sections. This picture suggests that mentioned MSD models can be interpreted as a variant of essentially one and the same theory. 113 refs.; 25 figs.; 9 tabs

  16. Current Direct Neutrino Mass Experiments

    Directory of Open Access Journals (Sweden)

    G. Drexlin

    2013-01-01

    Full Text Available In this contribution, we review the status and perspectives of direct neutrino mass experiments, which investigate the kinematics of β-decays of specific isotopes (3H, 187Re, 163Ho to derive model-independent information on the averaged electron (antineutrino mass. After discussing the kinematics of β-decay and the determination of the neutrino mass, we give a brief overview of past neutrino mass measurements (SN1987a-ToF studies, Mainz and Troitsk experiments for 3H, cryobolometers for 187Re. We then describe the Karlsruhe Tritium Neutrino (KATRIN experiment currently under construction at Karlsruhe Institute of Technology, which will use the MAC-E-Filter principle to push the sensitivity down to a value of 200 meV (90% C.L.. To do so, many technological challenges have to be solved related to source intensity and stability, as well as precision energy analysis and low background rate close to the kinematic endpoint of tritium β-decay at 18.6 keV. We then review new approaches such as the MARE, ECHO, and Project8 experiments, which offer the promise to perform an independent measurement of the neutrino mass in the sub-eV region. Altogether, the novel methods developed in direct neutrino mass experiments will provide vital information on the absolute mass scale of neutrinos.

  17. Boltzmann, Darwin and Directionality theory

    Science.gov (United States)

    Demetrius, Lloyd A.

    2013-09-01

    Boltzmann’s statistical thermodynamics is a mathematical theory which relates the macroscopic properties of aggregates of interacting molecules with the laws of their interaction. The theory is based on the concept thermodynamic entropy, a statistical measure of the extent to which energy is spread throughout macroscopic matter. Macroscopic evolution of material aggregates is quantitatively explained in terms of the principle: Thermodynamic entropy increases as the composition of the aggregate changes under molecular collision. Darwin’s theory of evolution is a qualitative theory of the origin of species and the adaptation of populations to their environment. A central concept in the theory is fitness, a qualitative measure of the capacity of an organism to contribute to the ancestry of future generations. Macroscopic evolution of populations of living organisms can be qualitatively explained in terms of a neo-Darwinian principle: Fitness increases as the composition of the population changes under variation and natural selection. Directionality theory is a quantitative model of the Darwinian argument of evolution by variation and selection. This mathematical theory is based on the concept evolutionary entropy, a statistical measure which describes the rate at which an organism appropriates energy from the environment and reinvests this energy into survivorship and reproduction. According to directionality theory, microevolutionary dynamics, that is evolution by mutation and natural selection, can be quantitatively explained in terms of a directionality principle: Evolutionary entropy increases when the resources are diverse and of constant abundance; but decreases when the resource is singular and of variable abundance. This report reviews the analytical and empirical support for directionality theory, and invokes the microevolutionary dynamics of variation and selection to delineate the principles which govern macroevolutionary dynamics of speciation and

  18. 75 FR 53611 - Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad-Direct...

    Science.gov (United States)

    2010-09-01

    ...] RIN 0691-AA75 Direct Investment Surveys: BE-577, Quarterly Survey of U.S. Direct Investment Abroad--Direct Transactions of U.S. Reporter With Foreign Affiliate AGENCY: Bureau of Economic Analysis, Commerce...-577 quarterly survey of U.S. direct investment abroad. The survey is conducted quarterly and obtains...

  19. Together in the same direction

    CERN Multimedia

    2013-01-01

    It’s sometimes difficult to explain the nature of global collaboration in particle physics: how fierce competition coexists with collaboration, and how, whatever our differences, we all pull in the same direction. But this week gave us two strong examples.   Firstly, on Wednesday, the Technical Design Report (TDR) for the International Linear Collider (ILC) was officially delivered to the International Committee for Future Accelerators, ICFA, the global body that oversees the development of major projects in particle physics. This event marks the culmination of years of effort through close global collaboration between labs around the world. It has seen tough collective decisions being taken between competing technologies, with all participating labs lining up behind the chosen option. And on Wednesday this week, it saw the linear collider community choosing CERN as one of the three venues for the official handover, despite the fact that CERN was not one of the original core labs ...

  20. Multi-directional program efficiency

    DEFF Research Database (Denmark)

    Asmild, Mette; Balezentis, Tomas; Hougaard, Jens Leth

    2016-01-01

    The present paper analyses both managerial and program efficiencies of Lithuanian family farms, in the tradition of Charnes et al. (Manag Sci 27(6):668–697, 1981) but with the important difference that multi-directional efficiency analysis rather than the traditional data envelopment analysis...... approach is used to estimate efficiency. This enables a consideration of input-specific efficiencies. The study shows clear differences between the efficiency scores on the different inputs as well as between the farm types of crop, livestock and mixed farms respectively. We furthermore find that crop...... farms have the highest program efficiency, but the lowest managerial efficiency and that the mixed farms have the lowest program efficiency (yet not the highest managerial efficiency)....

  1. New directions in gas processing

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Papers presented at the Insight conference held on January 30, 1996 in Calgary, Alberta, were contained in this volume. The conference was devoted to a discussion of new directions in the gas processing business, the changing business environment, new processing technologies, and means by which current facilities agreements can be adapted to the new commercial reality. High operating costs which have resulted in the downsizing and restructuring of the industry, and partnering with a third party in the gathering and processing operations, with apparently beneficial result both to plant owners, as well to third party processors, received the most attention. The relationship between the gas processor and the gas producer as they relate to the Petroleum Joint Venture Association (PJVA) Gas Processing Agreement, which defines the obligations of third parties, was the center of discussion. Regulatory changes and the industry's response to the changes was also on the agenda. Refs., tabs., figs

  2. Direct reconstruction of dark energy.

    Science.gov (United States)

    Clarkson, Chris; Zunckel, Caroline

    2010-05-28

    An important issue in cosmology is reconstructing the effective dark energy equation of state directly from observations. With so few physically motivated models, future dark energy studies cannot only be based on constraining a dark energy parameter space. We present a new nonparametric method which can accurately reconstruct a wide variety of dark energy behavior with no prior assumptions about it. It is simple, quick and relatively accurate, and involves no expensive explorations of parameter space. The technique uses principal component analysis and a combination of information criteria to identify real features in the data, and tailors the fitting functions to pick up trends and smooth over noise. We find that we can constrain a large variety of w(z) models to within 10%-20% at redshifts z≲1 using just SNAP-quality data.

  3. GLOBALIZATION AND FOREIGN DIRECT INVESTMENTS

    Directory of Open Access Journals (Sweden)

    Elena Chirilă – Donciu

    2013-07-01

    Full Text Available Mobilizing financial resources to cover investment needs is a concern of all countries, developed or developing ones, of consolidated market economies or emerging ones. A distinctive characteristic of Global Economy over the last few decades has been the rising rate and impressive increase in Foreign Direct Investment (FDI. The purpose of this research is to analyse global FDI inflows in Europe and in Romania. The results of the research support the idea that the balance of economic power is changing in the world economy and the countries that own a stable and solid industrial base are at an advantage. The new trends determined by the economic crisis in the field of FDI refer to the growing percentage of developing and emerging countries in the global flows of FDI.

  4. Direct Wittig Olefination of Alcohols.

    Science.gov (United States)

    Li, Qiang-Qiang; Shah, Zaher; Qu, Jian-Ping; Kang, Yan-Biao

    2018-01-05

    A base-promoted transition metal-free approach to substituted alkenes using alcohols under aerobic conditions using air as the inexpensive and clean oxidant is described. Aldehydes are relatively difficult to handle compared to corresponding alcohols due to their volatility and penchant to polymerize and autoxidize. Wittig ylides are easily oxidized to aldehydes and consequently form homo-olefination products. By the strategy of simultaneously in situ generation of ylides and aldehydes, for the first time, alcohols are directly transferred to olefins with no need of prepreparation of either aldehydes or ylides. Thus, the di/monocontrollable olefination of diols is accomplished. This synthetically practical method has been applied in the gram-scale synthesis of pharmaceuticals, such as DMU-212 and resveratrol from alcohols.

  5. Direct Reduction of Iron Ore

    Science.gov (United States)

    Small, M.

    1981-04-01

    In the search for a pure, available iron source, steelmakers are focusing their attention on Directly Reduced Iron (DRI). This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Commercially, DRI is generated in four different reactors: shaft (moving-bed), rotary kiln, fluidized bed, and retort (fixed-bed). Annual worldwide production capacity approaches 33 million metric tons. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace (EF) steelmaking. DRI is generally of a quality superior to current grades of scrap, with steels produced more efficiently in the EF and containing lower levels of impurities. However, present economics favor EF steel production with scrap. But this situation could change within this decade because of a developing scarcity of good quality scrap.

  6. Reasoning about cardinal directions between extended objects

    OpenAIRE

    Liu, Weiming; Zhang, Xiaotong; Li, Sanjiang; Ying, Mingsheng

    2010-01-01

    Direction relations between extended spatial objects are important commonsense knowledge. Recently, Goyal and Egenhofer proposed a formal model, known as Cardinal Direction Calculus (CDC), for representing direction relations between connected plane regions. CDC is perhaps the most expressive qualitative calculus for directional information, and has attracted increasing interest from areas such as artificial intelligence, geographical information science, and image retrieval. Given a network ...

  7. Invariance of directed spaces and persistence

    DEFF Research Database (Denmark)

    2006-01-01

    With motivations arising from concurrency theory within Computer Science, a new field of research, directed algebraic topology, has emerged. The main characteristic is, that it involves spaces of "directed paths'' (or timed paths, executions) in a "directed space''; these directed paths can be co...

  8. 40 CFR 73.72 - Direct sales.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Direct sales. 73.72 Section 73.72... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.72 Direct sales. Allowances that were formerly part of the direct sale program, which has been terminated under...

  9. Isomorphisms and traversability of directed path graphs

    NARCIS (Netherlands)

    Broersma, Haitze J.; Li, Xueliang; Li, X.

    1998-01-01

    The concept of a line digraph is generalized to that of a directed path graph. The directed path graph $\\forw P_k(D)$ of a digraph $D$ is obtained by representing the directed paths on $k$ vertices of $D$ by vertices. Two vertices are joined by an arc whenever the corresponding directed paths in $D$

  10. Direct strip casting of steel - historical perspective and future direction

    International Nuclear Information System (INIS)

    Manohar, P.A.; Hunter, A.; Ferry, M.

    2000-01-01

    The commercialisation of direct strip casting (DSC) of steel represents the realisation of a dream cherished by engineers for over one hundred and fifty years. The story of the global competition for DSC of steel, that has ingredients of romanticism of chasing of a dream, adventure and intrigue, is being played out across continents over dozens of decades with an interplay of setbacks and successes. At this stage, DSC is set to make a profound impact on the steelmaking landscape. This paper reviews the important milestones in this compelling story, presents the current status and then gazes into the crystal ball in an attempt to predict which turn the story may take in the near future. The constraints and critical challenges for the successful commercialisation of DSC are highlighted. Recent results are discussed relating the production process to quality control and properties of unalloyed, low carbon strip-cast steels. future metallurgical challenges include a better understanding of solidification mechanism during high-speed casting and secondary processing variables affecting the final microstructure of austenitic grains

  11. Direct digital conversion detector technology

    Science.gov (United States)

    Mandl, William J.; Fedors, Richard

    1995-06-01

    Future imaging sensors for the aerospace and commercial video markets will depend on low cost, high speed analog-to-digital (A/D) conversion to efficiently process optical detector signals. Current A/D methods place a heavy burden on system resources, increase noise, and limit the throughput. This paper describes a unique method for incorporating A/D conversion right on the focal plane array. This concept is based on Sigma-Delta sampling, and makes optimum use of the active detector real estate. Combined with modern digital signal processors, such devices will significantly increase data rates off the focal plane. Early conversion to digital format will also decrease the signal susceptibility to noise, lowering the communications bit error rate. Computer modeling of this concept is described, along with results from several simulation runs. A potential application for direct digital conversion is also reviewed. Future uses for this technology could range from scientific instruments to remote sensors, telecommunications gear, medical diagnostic tools, and consumer products.

  12. Direct anti-HCV agents

    Directory of Open Access Journals (Sweden)

    Xingquan Zhang

    2016-01-01

    Full Text Available Unlike human immunodeficiency virus (HIV and hepatitis B virus (HBV, hepatitis C virus (HCV infection is a curable disease. Current direct antiviral agent (DAA targets are focused on HCV NS3/4A protein (protease, NS5B protein (polymerase and NS5A protein. The first generation of DAAs includes boceprevir and telaprevir, which are protease inhibitors and were approved for clinical use in 2011. The cure rate for genotype 1 patients increased from 45% to 70% when boceprevir or telaprevir was added to standard PEG-IFN/ribavirin. More effective and less toxic second generation DAAs supplanted these drugs by 2013. The second generation of DAAs includes sofosbuvir (Sovaldi, simeprevir (Olysio, and fixed combination medicines Harvoni and Viekira Pak. These drugs increase cure rates to over 90% without the need for interferon and effectively treat all HCV genotypes. With these drugs the “cure HCV” goal has become a reality. Concerns remain about drug resistance mutations and the high cost of these drugs. The investigation of new HCV drugs is progressing rapidly; fixed dose combination medicines in phase III clinical trials include Viekirax, asunaprevir+daclatasvir+beclabuvir, grazoprevir+elbasvir and others.

  13. Direct probability mapping of contaminants

    International Nuclear Information System (INIS)

    Rautman, C.A.

    1993-01-01

    Exhaustive characterization of a contaminated site is a physical and practical impossibility. Descriptions of the nature, extent, and level of contamination, as well as decisions regarding proposed remediation activities, must be made in a state of uncertainty based upon limited physical sampling. Geostatistical simulation provides powerful tools for investigating contaminant levels, and in particular, for identifying and using the spatial interrelationships among a set of isolated sample values. This additional information can be used to assess the likelihood of encountering contamination at unsampled locations and to evaluate the risk associated with decisions to remediate or not to remediate specific regions within a site. Past operation of the DOE Feed Materials Production Center has contaminated a site near Fernald, Ohio, with natural uranium. Soil geochemical data have been collected as part of the Uranium-in-Soils Integrated Demonstration Project. These data have been used to construct a number of stochastic images of potential contamination for parcels approximately the size of a selective remediation unit. Each such image accurately reflects the actual measured sample values, and reproduces the univariate statistics and spatial character of the extant data. Post-processing of a large number of these equally likely, statistically similar images produces maps directly showing the probability of exceeding specified levels of contamination. Evaluation of the geostatistical simulations can yield maps representing the expected magnitude of the contamination for various regions and other information that may be important in determining a suitable remediation process or in sizing equipment to accomplish the restoration

  14. Future Directions in Ultraviolet Spectroscopy

    Science.gov (United States)

    Sonneborn, George (Editor); Moos, Warren; VanSteenberg, Michael

    2009-01-01

    The 'Future Directions in Ultraviolet Spectroscopy' conference was inspired by the accomplishments of the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission. The FUSE mission was launched in June 1999 and spent over eight years exploring the far-ultraviolet universe, gathering over 64 million seconds of high-resolution spectral data on nearly 3000 astronomical targets. The goal of this conference was not only to celebrate the accomplishments of FUSE, but to look toward the future and understand the major scientific drivers for the ultraviolet capabilities of the next generation fo space observatories. Invited speakers presented discussions based on measurements made by FUSE and other ultraviolet instruments, assessed their connection with measurements made with other techniques and, where appropriate, discussed the implications of low-z measurements for high-z phenomena. In addition to the oral presentations, many participants presented poster papers. The breadth of these presentation made it clear that much good science is still in progress with FUSE data and that these result will continue to have relevance in many scientific areas.

  15. New directions for veterinary technology.

    Science.gov (United States)

    Chadderdon, Linda M; Lloyd, James W; Pazak, Helene E

    2014-01-01

    Veterinary technology has generally established itself well in companion-animal and mixed-animal veterinary medical practice, but the career's growth trajectory is uncertain. Michigan State University (MSU) convened a national conference, "Creating the Future of Veterinary Technology-A National Dialogue," in November 2011 to explore ways to elevate the veterinary technician/technologist's role in the veterinary medical profession and to identify new directions in which the career could expand. Veterinary technicians/technologists might advance their place in private practice by not only improving their clinical skills, but by also focusing on areas such as practice management, leadership training, business training, conflict resolution, information technology, and marketing/communications. Some new employment settings for veterinary technicians/technologists include more participation within laboratory animal medicine and research, the rural farm industry, regulatory medicine, and shelter medicine. Achieving these ends would call for new training options beyond the current 2-year and 4-year degree programs. Participants suggested specialty training programs, hybrid programs of various types, online programs, veterinary technician residency programs of 12-18 months, and more integration of veterinary technician/technology students and veterinary medicine students at colleges of veterinary medicine.

  16. Laboratory directed research and development

    Energy Technology Data Exchange (ETDEWEB)

    1991-11-15

    The purposes of Argonne's Laboratory Directed Research and Development (LDRD) Program are to encourage the development of novel concepts, enhance the Laboratory's R D capabilities, and further the development of its strategic initiatives. Among the aims of the projects supported by the Program are establishment of engineering proof-of-principle''; development of an instrumental prototype, method, or system; or discovery in fundamental science. Several of these project are closely associated with major strategic thrusts of the Laboratory as described in Argonne's Five Year Institutional Plan, although the scientific implications of the achieved results extend well beyond Laboratory plans and objectives. The projects supported by the Program are distributed across the major programmatic areas at Argonne. Areas of emphasis are (1) advanced accelerator and detector technology, (2) x-ray techniques in biological and physical sciences, (3) advanced reactor technology, (4) materials science, computational science, biological sciences and environmental sciences. Individual reports summarizing the purpose, approach, and results of projects are presented.

  17. Some directions in ecological theory.

    Science.gov (United States)

    Kendall, Bruce E

    2015-12-01

    The role of theory within ecology has changed dramatically in recent decades. Once primarily a source of qualitative conceptual framing, ecological theories and models are now often used to develop quantitative explanations of empirical patterns and to project future dynamics of specific ecological systems. In this essay, I recount my own experience of this transformation, in which accelerating computing power and the widespread incorporation of stochastic processes into ecological theory combined to create some novel integration of mathematical and statistical models. This stronger integration drives theory towards incorporating more biological realism, and I explore ways in which we can grapple with that realism to generate new general theoretical insights. This enhanced realism, in turn, may lead to frameworks for projecting ecological responses to anthropogenic change, which is, arguably, the central challenge for 21st-century ecology. In an era of big data and synthesis, ecologists are increasingly seeking to infer causality from observational data; but conventional biometry provides few tools for this project. This is a realm where theorists can and should play an important role, and I close by pointing towards some analytical and philosophical approaches developed in our sister discipline of economics that address this very problem. While I make no grand prognostications about the likely discoveries of ecological theory over the coming century, you will find in this essay a scattering of more or less far-fetched ideas that I, at least, think are interesting and (possibly) fruitful directions for our field.

  18. Low backlash direct drive actuator

    Science.gov (United States)

    Kuklo, Thomas C.

    1994-01-01

    A low backlash direct drive actuator is described which comprises a motor such as a stepper motor having at least 200 steps per revolution; a two part hub assembly comprising a drive hub coaxially attached to the shaft of the motor and having a plurality of drive pins; a driven hub having a plurality of bores in one end thereof in alignment with the drive pins in the drive hub and a threaded shaft coaxially mounted in an opposite end of the driven hub; and a housing having a central bore therein into which are fitted the drive hub and driven hub, the housing having a motor mount on one end thereof to which is mounted the stepper motor, and a closed end portion with a threaded opening therein coaxial with the central bore in the housing and receiving therein the threaded shaft attached to the driven hub. Limit switches mounted to the housing cooperate with an enlarged lip on the driven hub to limit the lateral travel of the driven hub in the housing, which also acts to limit the lateral travel of the threaded shaft which functions as a lead screw.

  19. DIRECT INVESTMENT ON REGIONAL MARKETS

    Directory of Open Access Journals (Sweden)

    LIVIU NEAMŢU

    2013-08-01

    Full Text Available Foreign direct investment are that category of investments that allow participation in leadership andeffective control of the companies in which it invests. It's so new firms, as well as the establishment ofinternational operations of the company through expansion of existing operations. Typically, the companyincurred in a market that is confined to a distinct geographical area, but the limits of market changes. Thechange can be the result of higher management decisions on market opening and development of a newtechnology or product. Markets with a lower level of development are likely to attract a higher level of directinvestments than those in more developed countries. The specific reasons behind the decision of a company toinvest abroad are operating efficiency, reduce risk, market development and Government policy in the hostcountry. Transnational corporations are large conglomerates which consists of the parent company and itssubsidiaries/branches, both in the country of residence and abroad. Transnational corporations affect stronglyboth the production and the world of international economic relations. This influence is determined by themotivations of expansion that they promote. The expansion of transnational corporations has as satisfying"ambitions" of global expansion, and impulsionate getting supraprofiturilor. The strength of these structures isbased on maximizing profits.

  20. Modern Directions for Potentiometric Sensors

    Science.gov (United States)

    Bakker, Eric; Chumbimuni-Torres, Karin

    2009-01-01

    This paper gives an overview of the newest developments of polymeric membrane ion-selective electrodes. A short essence of the underlying theory is given, emphasizing how the electromotive force may be used to assess binding constants of the ionophore, and how the selectivity and detection limit are related to the underlying membrane processes. The recent developments in lowering the detection limits of ISEs are described, including recent approaches of developing all solid state ISEs, and breakthroughs in detecting ultra-small quantities of ions at low concentrations. These developments have paved the way to use potentiometric sensors as in ultra-sensitive affinity bioanalysis in conjunction with nanoparticle labels. Recent results establish that potentiometry compares favorably to electrochemical stripping analysis. Other new developments with ion-selective electrodes are also described, including the concept of backside calibration potentiometry, controlled current coulometry, pulsed chronopotentiometry, and localized flash titration with ion-selective membranes to design sensors for the direct detection of total acidity without net sample perturbation. These developments have further opened the field for exciting new possibilities and applications. PMID:19890473

  1. The direct aromatization of methane

    Energy Technology Data Exchange (ETDEWEB)

    Marcelin, G.; Oukaci, R.; Migone, R.A.; Kazi, A.M. [Altamira Instruments, Pittsburgh, PA (United States)

    1995-12-31

    The thermal decomposition of methane shows significant potential as a process for the production of higher unsaturated and aromatic hydrocarbons when the extent of the reaction is limited. Thermodynamic calculations have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that when the reaction is limited to the formation of C{sub 2} to C{sub 10} products, yields of aromatics can exceed 40% at temperatures of 1200{degrees}C. Preliminary experiments have shown that cooling the product and reacting gases as the reaction proceeds can significantly reduce or eliminate the formation of solid carbon and heavier (C{sub 10+}) materials. Much work remains to be done in optimizing the quenching process and this is one of the goals of this program. Means to lower the temperature of the reaction are being studied as this result in a more feasible commercial process due to savings realized in energy and material of construction costs. The use of free-radical generators and catalysts will be investigated as a means of lowering the reaction temperature thus allowing faster quenching. It is highly likely that such studies will lead to a successful direct methane to higher hydrocarbon process.

  2. Research Directions in Anthropological Pragmatics

    Directory of Open Access Journals (Sweden)

    Piotr P. Chruszczewski

    2011-08-01

    Full Text Available Anthropological linguistics, and by default also anthropological pragmatics, grew as sub-disciplines of both anthropology and linguistics. “The intellectual basis for anthropological linguistics in the United States derives from Boas ([1911] 1966, whose interests and concerns led to the anthropological view of language, which is that language is an integral part of culture (…” (Klein 2006: 296. Pragmatics enters the scene, telling the researcher how to analyse the aforementioned phenomena. Therefore, anthropological pragmatics would be responsible for equipping the researcher with tools, for it is language and language-oriented mechanisms of communication, the study of which provides a much clearer insight into cultural phenomena which often direct the use of language representing culture from both the synchronic and the diachronic point of view. “[O]ne approaches language from an anthropological view, which includes the uses of language and the uses of silence, as well as the cultural problems involved in silence and speech” (ibid..

  3. Direct Fast-Neutron Detection

    International Nuclear Information System (INIS)

    DC Stromswold; AJ Peurrung; RR Hansen; PL Reeder

    2000-01-01

    Direct fast-neutron detection is the detection of fast neutrons before they are moderated to thermal energy. We have investigated two approaches for using proton-recoil in plastic scintillators to detect fast neutrons and distinguish them from gamma-ray interactions. Both approaches use the difference in travel speed between neutrons and gamma rays as the basis for separating the types of events. In the first method, we examined the pulses generated during scattering in a plastic scintillator to see if they provide a means for distinguishing fast-neutron events from gamma-ray events. The slower speed of neutrons compared to gamma rays results in the production of broader pulses when neutrons scatter several times within a plastic scintillator. In contrast, gamma-ray interactions should produce narrow pulses, even if multiple scattering takes place, because the time between successive scattering is small. Experiments using a fast scintillator confirmed the presence of broader pulses from neutrons than from gamma rays. However, the difference in pulse widths between neutrons and gamma rays using the best commercially available scintillators was not sufficiently large to provide a practical means for distinguishing fast neutrons and gamma rays on a pulse-by-pulse basis. A faster scintillator is needed, and that scintillator might become available in the literature. Results of the pulse-width studies were presented in a previous report (peurrung et al. 1998), and they are only summarized here

  4. ANSTO - achievements and future directions

    International Nuclear Information System (INIS)

    Garnett, H. M.

    1997-01-01

    In the opening keynote address to the conference, Professor Helen Garnett, Executive Director of ANSTO, outlined the Organisation's main achievements and its future directions. In the ten years which have elapsed since its inception in 1987, ANSTO has evolved into a forward thinking, proactive nuclear science and technology Organisation. Its vision for the future is for nuclear science and technology to be accepted as benefiting all Australians and for ANSTO to be acknowledged as the premier nuclear science and technology organisation within the Asia Pacific Region. At the same time the organisation has continually reviewed and evaluated what it was doing and how it was doing. At the end of its first decade, it has enhanced the productivity from its research and development activities, received a positive evaluation on the impact that the application of this knowledge is having on the minerals and other industrial sectors, and focussed its research and development into a few areas where substantial teams of ANSTO staff, working cooperatively with staff from universities, other national organisations and industry, can have significant impact. ANSTO now has four parallel activities: the conduct of research and development, the provision of expert technical advice, the operation of national nuclear facilities and the commercial marketing of products and services. The recent announcement by Australian Government to replace HIFAR reactor with a leading medium flux reactor facility, will enable ANSTO to develop world class capability in selected areas of neutron science and to became an acknowledged regional centre, particular in cold neutron science

  5. Cometary Defense with Directed Energy

    Science.gov (United States)

    Zhang, Q.; Lubin, P. M.; Hughes, G. B.

    2016-12-01

    Cometary impacts pose a long-term hazard to humans on Earth. Due to their comparative rarity, most planetary defense schemes neglect the comet threat, choosing instead to focus exclusively on mitigating asteroid impacts. Methods like kinetic impactors may be suitable for deflecting near-Earth asteroids (NEAs) and Jupiter-family comets (JFCs), both of which are characterized by low inclination orbits and short orbital periods which favor early detection—characteristics ideal for an interception mission. In contrast, Halley-type comets (HTCs) and long-period comets (LPCs) are often found in high inclination orbits rarely more than 2 yr prior to reaching Earth's orbit. Unless discovered and identified in a prior apparition—often centuries or millennia earlier, if ever—timely interception of a threatening HTC or LPC is improbable even with preparation, with missions demanding delta-v budgets often in excess of 30 km/s. Active comets, however, are already naturally perturbed from purely gravitational trajectories through solar-driven sublimation of volatiles. Further deflection may be achieved by supplementing the solar radiation with an artificial directed energy source such as by one or more laser arrays positioned on or near Earth. Simulations were developed with models derived from the known solar nongravitational perturbations of typical comets. Results suggest that a diffraction-limited 500 m array operating at 10 GW for 10 min/day may be sufficient to divert a typical active 500 m comet from an impact given 1 yr. A larger 1 km array operating at 100 GW for 100 s/day is similarly effective. Care must be taken to ensure the target remains intact throughout the deflection period due to comets' low compressive strength and resulting propensity for disintegration at high incident flux.

  6. Matlab Source Code for Species Transport through Nafion Membranes in Direct Ethanol, Direct Methanol, and Direct Glucose Fuel Cells

    OpenAIRE

    JH, Summerfield; MW, Manley

    2016-01-01

    A simple simulation of chemical species movement is presented. The species traverse a Nafion membrane in a fuel cell. Three cells are examined: direct methanol, direct ethanol, and direct glucose. The species are tracked using excess proton concentration, electric field strength, and voltage. The Matlab computer code is provided.

  7. Future directions of ecosystem science

    Science.gov (United States)

    Baron, Jill S.; Galvin, Kathleen A.

    1990-01-01

    , and global--have not replaced one another (Clark and Holling 1985). Instead, the effects are superimposed, creating what some perceive as impending global environmental crisis (Clark 1989, MacNeill 1989, WCED 1987). Public demands are developing for economic, political, social, and environmental efforts directed toward creating a state of global sustainability.

  8. Wave directional spectrum from array measurements

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, A.A; Sarma, Y; Menon, H.B.

    Using the method of Esteva (1976, 1977), whcih assumes that at the frequency band the waves approach from just a single "mean" wave direction, wave direction has been consistently, accurately and unambiguously evaluated as a function of frequency...

  9. Towards host-directed therapies for tuberculosis.

    Science.gov (United States)

    Zumla, Alimuddin; Maeurer, Markus; Chakaya, Jeremiah; Hoelscher, Michael; Ntoumi, Francine; Rustomjee, Roxana; Vilaplana, Cristina; Yeboah-Manu, Dorothy; Rasolof, Voahangy; Munderi, Paula; Singh, Nalini; Aklillu, Eleni; Padayatchi, Nesri; Macete, Eusebio; Kapata, Nathan; Mulenga, Modest; Kibiki, Gibson; Mfinanga, Sayoki; Nyirenda, Thomas; Maboko, Leonard; Garcia-Basteiro, Alberto; Rakotosamimanana, Niaina; Bates, Matthew; Mwaba, Peter; Reither, Klaus; Gagneux, Sebastien; Edwards, Sarah; Mfinanga, Elirehema; Abdulla, Salim; Cardona, Pere-Joan; Russell, James B W; Gant, Vanya; Noursadeghi, Mahdad; Elkington, Paul; Bonnet, Maryline; Menendez, Clara; Dieye, Tandakha N; Diarra, Bassirou; Maiga, Almoustapha; Aseffa, Abraham; Parida, Shreemanta; Wejse, Christian; Petersen, Eskild; Kaleebu, Pontiano; Oliver, Matt; Craig, Gill; Corrah, Tumena; Tientcheu, Leopold; Antonio, Martin; Rao, Martin; McHugh, Timothy D; Sheikh, Aziz; Ippolito, Giuseppe; Ramjee, Gita; Kaufmann, Stefan H E; Churchyard, Gavin; Steyn, Andrie; Grobusch, Martin; Sanne, Ian; Martinson, Neil; Madansein, Rajhmun; Wilkinson, Robert J; Mayosi, Bongani; Schito, Marco; Wallis, Robert S

    2015-08-01

    The treatment of tuberculosis is based on combinations of drugs that directly target Mycobacterium tuberculosis. A new global initiative is now focusing on a complementary approach of developing adjunct host-directed therapies.

  10. Directional outlyingness for multivariate functional data

    KAUST Repository

    Dai, Wenlin; Genton, Marc G.

    2018-01-01

    The direction of outlyingness is crucial to describing the centrality of multivariate functional data. Motivated by this idea, classical depth is generalized to directional outlyingness for functional data. Theoretical properties of functional

  11. Direct Interval Forecasting of Wind Power

    DEFF Research Database (Denmark)

    Wan, Can; Xu, Zhao; Pinson, Pierre

    2013-01-01

    This letter proposes a novel approach to directly formulate the prediction intervals of wind power generation based on extreme learning machine and particle swarm optimization, where prediction intervals are generated through direct optimization of both the coverage probability and sharpness...

  12. Directional Collision Avoidance in Ad Hoc Networks

    National Research Council Canada - National Science Library

    Wang, Yu; Garcia-Luna-Aceves, J. J

    2004-01-01

    This paper analyzes the performance of directional collision avoidance schemes, in which antenna systems are used to direct the transmission and reception of control and data packets in channel access...

  13. Directional Wide-Angle Range Finder (DWARF)

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation, the Directional Wide-Angle Range Finder (DWARF) is the creation of a laser range-finder with a wide field-of-view (FOV) and a directional...

  14. The spatial patterns of directional phenotypic selection

    KAUST Repository

    Siepielski, Adam M.; Gotanda, Kiyoko M.; Morrissey, Michael B.; Diamond, Sarah E.; DiBattista, Joseph; Carlson, Stephanie Marie

    2013-01-01

    the spatial patterns of selection, namely the extent of variation among populations in the strength and direction of selection. Here, we analyse a data set of spatially replicated studies of directional phenotypic selection from natural populations. The data

  15. 78 FR 72834 - Airworthiness Directives; SOCATA Airplanes

    Science.gov (United States)

    2013-12-04

    ... Airworthiness Directives; SOCATA Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... airworthiness directive (AD) for SOCATA Model TBM 700 airplanes. This proposed AD results from mandatory... review this referenced service information at the FAA, Small Airplane Directorate, 901 Locust, Kansas...

  16. AIRTV: Broadband Direct to Aircraft

    Science.gov (United States)

    Sorbello, R.; Stone, R.; Bennett, S. B.; Bertenyi, E.

    2002-01-01

    Airlines have been continuously upgrading their wide-body, long-haul aircraft with IFE (in-flight entertainment) systems that can support from 12 to 24 channels of video entertainment as well as provide the infrastructure to enable in-seat delivery of email and internet services. This is a direct consequence of increased passenger demands for improved in-flight services along with the expectations that broadband delivery systems capable of providing live entertainment (news, sports, financial information, etc.) and high speed data delivery will soon be available. The recent events of Sept. 11 have slowed the airline's upgrade of their IFE systems, but have also highlighted the compelling need for broadband aeronautical delivery systems to include operational and safety information. Despite the impact of these events, it is estimated that by 2005 more than 3000 long haul aircraft (servicing approximately 1 billion passengers annually) will be fully equipped with modern IFE systems. Current aircraft data delivery systems, which use either Inmarsat or NATS, are lacking in bandwidth and consequently are unsuitable to satisfy passenger demands for broadband email/internet services or the airlines' burgeoning data requirements. Present live video delivery services are limited to regional coverage and are not readily expandable to global or multiregional service. Faced with a compelling market demand for high data transport to aircraft, AirTV has been developing a broadband delivery system that will meet both passengers' and airlines' needs. AirTV is a global content delivery system designed to provide a range of video programming and data services to commercial airlines. When AirTV is operational in 2004, it will provide a broadband connection directly to the aircraft, delivering live video entertainment, internet/email service and essential operational and safety data. The system has been designed to provide seamless global service to all airline routes except for those

  17. Hydrothermal industrialization: direct heat development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-01

    A description of hydrothermal resources suitable for direct applications, their associated temperatures, geographic distribution and developable capacity are given. An overview of the hydrothermal direct-heat development infrastructure is presented. Development activity is highlighted by examining known and planned geothermal direct-use applications. Underlying assumptions and results for three studies conducted to determine direct-use market penetration of geothermal energy are discussed.

  18. 31 CFR 357.26 - Direct Deposit.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Direct Deposit. 357.26 Section 357.26 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE... AND BILLS HELD IN LEGACY TREASURY DIRECT Legacy Treasury Direct Book-Entry Securities System (Legacy...

  19. Directed Forgetting of Recently Recalled Autobiographical Memories

    Science.gov (United States)

    Barnier, Amanda J.; Conway, Martin A.; Mayoh, Lyndel; Speyer, Joanne; Avizmil, Orit; Harris, Celia B.

    2007-01-01

    In 6 experiments, the authors investigated list-method directed forgetting of recently recalled autobiographical memories. Reliable directed forgetting effects were observed across all experiments. In 4 experiments, the authors examined the impact of memory valence on directed forgetting. The forget instruction impaired recall of negative,…

  20. 78 FR 53635 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-08-30

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Airbus Model A330-200 and... Sec. 39.13 by adding the following new airworthiness directive (AD): 2013-17-03 Airbus: Amendment 39...

  1. Object Detection: Current and Future Directions

    Directory of Open Access Journals (Sweden)

    Rodrigo eVerschae

    2015-11-01

    Full Text Available Object detection is a key ability required by most computer and robot vision systems. The latest research on this area has been making great progress in many directions. In the current manuscript we give an overview of past research on object detection, outline the current main research directions, and discuss open problems and possible future directions.

  2. 19 CFR 351.509 - Direct taxes.

    Science.gov (United States)

    2010-04-01

    ... Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE ANTIDUMPING AND COUNTERVAILING DUTIES Identification and Measurement of Countervailable Subsidies § 351.509 Direct taxes. (a) Benefit—(1) Exemption or... direct tax (e.g., an income tax), or a reduction in the base used to calculate a direct tax, a benefit...

  3. Potential Dimension Yields From Direct Processing

    Science.gov (United States)

    Wenjie Lin; D. Earl Kline; Philip A. Araman

    1994-01-01

    As the price of timber increases and environmental leigslation limits harvestable log volumes, the process of converting logs directly into dimension parts needs further exploration. Direct processing converts logs directly into rough green dimension parts without the intermediate steps of lumber manufacturing, grading, trading, shipping and drying. A major attraction...

  4. Empirical Evaluation of Directional-Dependence Tests

    Science.gov (United States)

    Thoemmes, Felix

    2015-01-01

    Testing of directional dependence is a method to infer causal direction that recently has attracted some attention. Previous examples by e.g. von Eye and DeShon (2012a) and extensive simulation studies by Pornprasertmanit and Little (2012) have demonstrated that under specific assumptions, directional-dependence tests can recover the true causal…

  5. Directe en indirecte werknemersparticipatie in Europa

    NARCIS (Netherlands)

    van Houten, Gijs; Akkerman, Agnes; Sluiter, Roderick; Jansen, Giedo; Vermeylen, Greet

    2016-01-01

    This study looks at different forms of direct and indirect employee participation in the EU. The research questions are: (1) which forms of direct and indirect employee participation can we distinguish?; (2) to what extent do forms of direct and indirect employee participation coincide within

  6. 14 CFR 212.7 - Direct sales.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights under...

  7. Determining Directional Dependency in Causal Associations

    Science.gov (United States)

    Pornprasertmanit, Sunthud; Little, Todd D.

    2012-01-01

    Directional dependency is a method to determine the likely causal direction of effect between two variables. This article aims to critique and improve upon the use of directional dependency as a technique to infer causal associations. We comment on several issues raised by von Eye and DeShon (2012), including: encouraging the use of the signs of…

  8. The Direct Satellite Connection: Definitions and Prospects.

    Science.gov (United States)

    Wigand, Rolf T.

    1980-01-01

    Defines direct satellite broadcasting as the transmission of broadcast signals via high-powered satellites that permit direct reception of television or radio programs by means of small antennas. Outlines American, European, and Japanese plans for direct-to-home television reception and implications for the broadcasting industry. (JMF)

  9. Algorithm for counting large directed loops

    Energy Technology Data Exchange (ETDEWEB)

    Bianconi, Ginestra [Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Gulbahce, Natali [Theoretical Division and Center for Nonlinear Studies, Los Alamos National Laboratory, NM 87545 (United States)

    2008-06-06

    We derive a Belief-Propagation algorithm for counting large loops in a directed network. We evaluate the distribution of the number of small loops in a directed random network with given degree sequence. We apply the algorithm to a few characteristic directed networks of various network sizes and loop structures and compare the algorithm with exhaustive counting results when possible. The algorithm is adequate in estimating loop counts for large directed networks and can be used to compare the loop structure of directed networks and their randomized counterparts.

  10. Direct convertor based upon space charge effects

    International Nuclear Information System (INIS)

    Gitomer, S.J.

    1977-01-01

    A device capable of converting directly the kinetic energy of charged particles into electrical energy is considered. The device differs from earlier ones (such as Post's periodic focus electrostatic direct convertor) in that it makes use of the space charge repulsion in a high density charged particle beam. The beam is directed into a monotonic decelerating electrostatic field of a several-stage planar-finned structure. The collector fins coincide with vacuum equipotential surfaces. Space charge blowup of the beam directs particles onto various collector fins. The energy efficiency of a 4-stage device has been determined using a numberical simulation approach. We find that efficiencies approaching 75 percent are possible. An approximate scaling law is derived for the space charge based direct converter and a comparison is made to the periodic focus direct convertor. We find the space charge based direct convertor to be superior to a number of ways

  11. Temperature dependence of the ESR linewidth in the paramagnetic phase (T>TC) of R1-xBxMnO3+δ (R=La,Pr; B=Ca,Sr)

    International Nuclear Information System (INIS)

    Rettori, C.; Rao, D.; Singley, J.; Kidwell, D.; Oseroff, S.B.; Causa, M.T.; Neumeier, J.J.; McClellan, K.J.; Cheong, S.; Schultz, S.

    1997-01-01

    Electron spin resonance (ESR) experiments in the paramagnetic phase of R 1-x B x MnO 3+δ (R=La,Pr; B=Ca,Sr) show, for 1.1 T C approx-lt T approx-lt 2T C , a linear T increase of the resonance linewidth, ΔH, in powders, ceramic pellets, and single crystals. Above ∼2T C a slowdown in the T increase of ΔH is observed. The data resemble the results found in other ferromagnetic insulators where the spin-lattice relaxation involves a single-phonon process. We find that the one-phonon process may account for the linear T dependence of the linewidth observed up to ∼2T C . A large T dependence of the resonance intensity above T C was found in all the samples studied, suggesting the existence of spin clusters in these compounds over a wide range of temperature. copyright 1997 The American Physical Society

  12. Temperature dependence of the ESR linewidth in the paramagnetic phase (T{gt}T{sub C}) of R{sub 1{minus}x}B{sub x}MnO{sub 3+{delta}} (R=La,Pr; B=Ca,Sr)

    Energy Technology Data Exchange (ETDEWEB)

    Rettori, C.; Rao, D.; Singley, J.; Kidwell, D.; Oseroff, S.B. [San Diego State University, San Diego, California 92182 (United States); Causa, M.T. [Centro Atomico Bariloche and Instituto Balseiro 8400, San Carlos de Bariloche (Argentina); Neumeier, J.J.; McClellan, K.J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Cheong, S. [ATT Bell Laboratories, Murray Hill, New Jersey 07974 (United States); Schultz, S. [University of California, San Diego, California 92037 (United States)

    1997-02-01

    Electron spin resonance (ESR) experiments in the paramagnetic phase of R{sub 1{minus}x}B{sub x}MnO{sub 3+{delta}} (R=La,Pr; B=Ca,Sr) show, for 1.1 T{sub C}{approx_lt}T{approx_lt}2T{sub C}, a linear T increase of the resonance linewidth, {Delta}H, in powders, ceramic pellets, and single crystals. Above {approximately}2T{sub C} a slowdown in the T increase of {Delta}H is observed. The data resemble the results found in other ferromagnetic insulators where the spin-lattice relaxation involves a single-phonon process. We find that the one-phonon process may account for the linear T dependence of the linewidth observed up to {approximately}2T{sub C}. A large T dependence of the resonance intensity above T{sub C} was found in all the samples studied, suggesting the existence of {ital spin clusters} in these compounds over a wide range of temperature. {copyright} {ital 1997} {ital The American Physical Society}

  13. Verbal directionality and argument alternation in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2012-01-01

    The derivational morphology of verbs in Dinka includes a distinction between direction towards the deictic center (centripetal) and a direction not towards the deictic center (centrifugal). A goal adverbial requires a directional verb, and an object of such a verb refers to something that moves t...... of a simple verb may correspond to, respectively, a goal adverbial and an object of the directional verb. Another type of argument alternation results from the possibility of expressing a goal as an object of an applicative verb with an intransitive or transitive base.......(wards) an explicit or implicit goal. The object of a directional verb may play another role in the event described by the sentence than the object of the corresponding simple (and non-directional) verb. This gives rise to so-called argument alternation, in that, for instance, an object and an instrumental adverbial...

  14. A wide-range direction neutron spectrometer

    International Nuclear Information System (INIS)

    Luszik-Bhadra, M.; D'Errico, F.; Hecker, O.; Matzke, M.

    2002-01-01

    A new device is presented which has been developed for measuring the energy and direction of distribution of neutron fluence in fields of broad energy spectra (thermal to 100 MeV) and with a high background of photon, electron and muon radiation. The device was tested in reference fields with different energy and direction distributions of neutron fluence. The direction-integrated fluence spectra agree fairly well with reference spectra. In all cases, the ambient and personal dose equivalent values calculated from measured direction-differential spectra are within 35% of the reference values. Independent measurements of the directional dose equivalent were performed with a directional dose equivalent monitor based on superheated drop detectors

  15. Supplementary income. Direct selling in Germany

    International Nuclear Information System (INIS)

    Roesner, Sven

    2014-01-01

    This document treats, first, of the evolution of the German support mechanisms to renewable energy sources. Then, it presents the legal framework of direct electricity selling (goal, evolution, facilities in concern and eligibility criteria). Next, the operation of direct selling since August 2014 in Germany is presented (producers eligibility, over- and under-production, reference values, income, tariffs). Finally, the perspectives and conditions of direct selling success are summarized in the conclusion

  16. Direct Marketing Communication at SEAL Communication Company

    OpenAIRE

    Wachtler, Kamilla Dóra

    2010-01-01

    The appearance of the Internet and new, rapidly changing emerging online technologies have led to some fundamental changes in marketing -- especially direct marketing. Besides the growing popularity of the Internet, the appearance of databases and one-to-one marketing are challenging traditional marketing methods. This thesis attempts to illustrate how direct marketing techniques can be implemented in an IT company. It starts with an overview of the concepts of direct marketing and its techni...

  17. Spatial roles and verbal directionality in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2012-01-01

    This article deals with the interaction between two subsystems of the grammar of Dinka, a Western Nilotic language: (i) the semantic role of a place adverbial as location, source or goal, and (ii) deictic directionality expressed in the verb. Some place adverbials do not encode the distinction be...... verb. In clauses with a single place adverbial, moreover, a source adverbial requires either a non-directional verb or a centripetal verb, and a location adverbial requires a non-directional verb....

  18. Navy Telemedicine: Current Research and Future Directions

    National Research Council Canada - National Science Library

    Reed, Cheryl

    2002-01-01

    .... This report reviews military and civilian models for evaluating telemedicine systems in order to determine future directions for Navy telemedicine research within the current funding environment...

  19. NASA directives master list and index

    Science.gov (United States)

    1995-01-01

    This handbook sets forth in two parts, Master List of Management Directives and Index to NASA Management Directives, the following information for the guidance of users of the NASA Management Directives System. Chapter 1 contains introductory information material on how to use this handbook. Chapter 2 is a complete master list of agencywide management directives, describing each directive by type, number, effective date, expiration date, title, and organization code of the office responsible for the directive. Chapter 3 includes a consolidated numerical list of all delegations of authority and a breakdown of such delegation by the office or center to which special authority is assigned. Chapter 4 sets forth a consolidated list of all NASA handbooks (NHB's) and important footnotes covering the control and ordering of such documents. Chapter 5 is a consolidated list of NASA management directives applicable to the Jet Propulsion Laboratory. Chapter 6 is a consolidated list of NASA regulations published in the Code of Federal Regulations. Chapter 7 is a consolidated list of NASA regulations published in Title 14 of the Code of Federal Regulations. Complementary manuals to the NASA Management Directives System are described in Chapter 8. The second part contains an in depth alphabetical index to all NASA management directives other than handbooks, most of which are indexed by titles only.

  20. Regional impacts of abolishing direct payments

    DEFF Research Database (Denmark)

    Uthes, Sandra; Priorr, Annette; Zander, Peter

    2011-01-01

    The direct payment system of the Common Agricultural Policy (CAP) provides income transfers to European farmers. Recently, several countries including England and Sweden have advocated the elimination of direct payments after 2013. The extent to which an elimination of direct payments would affect...... with different production orientations and land management types was modeled under the presence and absence of direct payments using a combination of agent-based and bio-economic modeling. We found that the initial characteristics of the regions, such as the historical farm structure and regional site conditions...

  1. From Nonradiating Sources to Directionally Invisible Objects

    Science.gov (United States)

    Hurwitz, Elisa

    The goal of this dissertation is to extend the understanding of invisible objects, in particular nonradiating sources and directional nonscattering scatterers. First, variations of null-field nonradiating sources are derived from Maxwell's equations. Next, it is shown how to design a nonscattering scatterer by applying the boundary conditions for nonradiating sources to the scalar wave equation, referred to here as the "field cloak method". This technique is used to demonstrate directionally invisible scatterers for an incident field with one direction of incidence, and the influence of symmetry on the directionality is explored. This technique, when applied to the scalar wave equation, is extended to show that a directionally invisible object may be invisible for multiple directions of incidence simultaneously. This opens the door to the creation of optically switchable, directionally invisible objects which could be implemented in couplers and other novel optical devices. Next, a version of the "field cloak method" is extended to the Maxwell's electro-magnetic vector equations, allowing more flexibility in the variety of directionally invisible objects that can be designed. This thesis concludes with examples of such objects and future applications.

  2. On the Strong Direct Summand Conjecture

    Science.gov (United States)

    McCullough, Jason

    2009-01-01

    In this thesis, our aim is the study the Vanishing of Maps of Tor Conjecture of Hochster and Huneke. We mainly focus on an equivalent characterization called the Strong Direct Summand Conjecture, due to N. Ranganathan. Our results are separated into three chapters. In Chapter 3, we prove special cases of the Strong Direct Summand Conjecture in…

  3. An analysis of multislot directional coupler

    International Nuclear Information System (INIS)

    Arai, Hiroyuki; Goto, Naohisa; Yamamoto, Takumi.

    1986-03-01

    This paper presents an analysis of multislot directional coupler for monitoring the gyrotron output. We solved the boundary value problem of the directional coupler to investigate the detailed effect of finite thickness slot and mutual coupling between slots. Numerical data of coupler design is presented for non-resonant a pair slot, and mode sensitivity in overmoded waveguide is also evaluated. (author)

  4. 76 FR 69168 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-11-08

    ...-1225; Directorate Identifier 2010-NM-269-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 B4-2C, B4-103..., contact Airbus SAS-EAW (Airworthiness Office), 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France...

  5. 77 FR 66760 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-11-07

    ...-1162; Directorate Identifier 2012-NM-002-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter, A330... information identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point...

  6. 78 FR 39190 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-07-01

    ...-0543; Directorate Identifier 2012-NM-202-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A318, A319, A320, and... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  7. 77 FR 37829 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-06-25

    ...-0671; Directorate Identifier 2011-NM-096-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede an existing airworthiness directive (AD) that applies to certain Airbus Model... this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707...

  8. 78 FR 60798 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-10-02

    ...-0363; Directorate Identifier 2013-NM-031-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... directive (AD) for all Airbus Model A330-200, -300 and -200 Freighter series airplanes, and Model A340-200... information identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point...

  9. 77 FR 73340 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-12-10

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... earlier proposed airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series..., contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France...

  10. 78 FR 23105 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-04-18

    ... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Airbus Model... Agency] has received a report via Airbus and Messier-Bugatti-Dowty Ltd, from a Maintenance repair...

  11. 78 FR 29261 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-20

    ...-0424; Directorate Identifier 2013-NM-014-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter, A330... this proposed AD, contact Airbus SAS, Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707...

  12. 77 FR 11793 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-02-28

    ...-0185; Directorate Identifier 2011-NM-001-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 B4-103, B4-203... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  13. 77 FR 15636 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-16

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for all Airbus... identified in this proposed AD, contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte...

  14. 77 FR 60325 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-10-03

    ...-1253; Directorate Identifier 2011-NM-079-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... directive (AD) that would supersede an existing AD for certain Airbus Model A318, A319, A320, and A321... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  15. 78 FR 59295 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-09-26

    ...-0829; Directorate Identifier 2013-NM-085-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede airworthiness directive (AD) 2010-23- 12, which applies to certain Airbus... through Friday, except Federal holidays. For Airbus service information identified in this proposed AD...

  16. 78 FR 70003 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-11-22

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A300 series airplanes; Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model...

  17. 78 FR 18925 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-03-28

    ...-0212; Directorate Identifier 2012-NM-116-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-223F, -223, -321...., Monday through Friday, except Federal holidays. For Airbus service information identified in this...

  18. 77 FR 66762 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-11-07

    ...-1159; Directorate Identifier 2012-NM-028-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A310-203, -204, -222... information identified in this proposed AD, contact Airbus SAS--EAW (Airworthiness Office), 1 Rond Point...

  19. 76 FR 62673 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-10-11

    ...-1066; Directorate Identifier 2011-NM-050-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD), for certain Airbus Model A300 B2-1C, B2K-3C... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  20. 77 FR 49386 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-08-16

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for all Airbus..., except Federal holidays. For Airbus service information identified in this proposed AD, contact Airbus...

  1. 76 FR 72350 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-11-23

    ...-1253; Directorate Identifier 2011-NM-079-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A319, A320, and A321... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  2. 78 FR 51117 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-08-20

    ...-0698; Directorate Identifier 2012-NM-136-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede airworthiness directive (AD) 2006-06- 14, that applies to certain Airbus... information identified in this proposed AD, contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice...

  3. 76 FR 68671 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-11-07

    ...-1170; Directorate Identifier 2010-NM-264-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A300 B4-600, B4-600R, and... Friday, except Federal holidays. For Airbus service information identified in this proposed AD, contact...

  4. 76 FR 78524 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2011-12-19

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for Airbus... an aeroplane from the Airbus production line, a fault message was triggered on FDU1 [fire detection...

  5. 78 FR 46306 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-07-31

    ...-0632; Directorate Identifier 2013-NM-045-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 and -300 series... identified in this proposed AD, contact Airbus SAS, Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte...

  6. 78 FR 25902 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-03

    ...-0363; Directorate Identifier 2013-NM-031-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200, -300 and -200... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  7. 78 FR 79292 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-12-30

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) 2011-24-09 which applied to certain Airbus Model A340-200 and A340-300 series airplanes. AD... AD, contact Airbus SAS-- Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707 Blagnac...

  8. 77 FR 15644 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-16

    ...-0192; Directorate Identifier 2011-NM-225-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200 and -200... information identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point...

  9. 77 FR 51729 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-08-27

    ...-0810; Directorate Identifier 2011-NM-195-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200, A330-300... identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte...

  10. 78 FR 79333 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-12-30

    ...-1066; Directorate Identifier 2013-NM-021-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede airworthiness directive (AD) 2000-12- 12, for certain Airbus Model A300, A300... this proposed AD, contact Airbus SAS, Airworthiness Office--EAW, 1 Rond Point Maurice Bellonte, 31707...

  11. 78 FR 32345 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-30

    ... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Airbus Model A300... FedEx requested that copies of Airbus Service Bulletin A300-53- 6170, dated May 16, 2011, be provided...

  12. 78 FR 1723 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-01-09

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule; request for comments. SUMMARY: We are adopting a new airworthiness directive (AD) for all Airbus... Friday, except Federal holidays. For service information identified in this AD, contact Airbus...

  13. 78 FR 29666 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-21

    ...-0422; Directorate Identifier 2012-NM-097-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200 and -300... information identified in this proposed AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point...

  14. 78 FR 64156 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-10-28

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) for all Airbus Model A340-211 -212, -213, -311, -312, -313, -541, and -642 airplanes. This AD... information identified in this AD, contact Airbus SAS, Airworthiness Office--EAL, 1 Rond Point Maurice...

  15. 77 FR 26996 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-05-08

    ...-0427; Directorate Identifier 2011-NM-202-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A320-214 and-232... Friday, except Federal holidays. For service information identified in this proposed AD, contact Airbus...

  16. 77 FR 7523 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-02-13

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) for all Airbus Model A340-600 series airplanes. This AD requires modifying the fire.... Relevant Service Information Airbus has issued Mandatory Service Bulletin A340-26-5020, including Appendix...

  17. 78 FR 37498 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-06-21

    ...-0463; Directorate Identifier 2012-NM-165-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A330-200, -200... holidays. For service information identified in this proposed AD, contact Airbus SAS--Airworthiness Office...

  18. 77 FR 19067 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-30

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) for certain Airbus Model A321-131, -211, -212, and -231 airplanes. This AD requires a.... Relevant Service Information Airbus has issued Mandatory Service Bulletin A320-57-1120, Revision 01...

  19. 77 FR 12989 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-05

    ... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Airbus Model.... Airbus carried out an investigation, demonstrating that the life limit of retraction brackets must be...

  20. 78 FR 76572 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-12-18

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: We propose to adopt a new airworthiness directive (AD) for all Airbus..., except Federal holidays. For Airbus service information identified in this proposed AD, contact Airbus...

  1. 77 FR 19065 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-30

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) for all Airbus Model A340-600 series airplanes. This AD requires a detailed inspection for.... Relevant Service Information Airbus has issued All Operators Telex A340-25A5191, dated January 18, 2011...

  2. 77 FR 59149 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-09-26

    ...-1002; Directorate Identifier 2012-NM-052-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 B4-600, B4-600R...: Airbus: Docket No. FAA-2012-1002; Directorate Identifier 2012-NM- 052-AD. (a) Comments Due Date We must...

  3. 78 FR 9341 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-02-08

    ...-0088; Directorate Identifier 2011-NM-233-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede an existing airworthiness directive (AD) that applies to all Airbus Model... this proposed AD, contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte, 31707...

  4. 77 FR 64765 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-10-23

    ...-1105; Directorate Identifier 2012-NM-137-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A318, A319, and A320... identified in this proposed AD, contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte...

  5. 77 FR 66772 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-11-07

    ...-1158; Directorate Identifier 2011-NM-232-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to supersede an existing airworthiness directive (AD) that applies to all Airbus Model... that AD, Airbus has revised certain ALI documents, which require more restrictive maintenance...

  6. 77 FR 65146 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-10-25

    ...-1106; Directorate Identifier 2012-NM-084-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter, -200..., contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France...

  7. 77 FR 16492 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-21

    ...-0291; Directorate Identifier 2011-NM-168-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A318-112, and -121... identified in this proposed AD, contact Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte...

  8. 78 FR 17071 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-03-20

    ... Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for certain Airbus Model A330-200, -300, and -200 Freighter series airplanes; and all Airbus Model A340-200 and -300 series...

  9. 77 FR 73343 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-12-10

    ...-1224; Directorate Identifier 2012-NM-112-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A300 B4-600, B4-600R, and... holidays. For Airbus service information identified in this proposed AD, contact Airbus SAS-EAW...

  10. 78 FR 14029 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-03-04

    ...-0096; Directorate Identifier 2012-NM-143-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A318-112, A319-111... Airbus, Airworthiness Office--EAS, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; telephone...

  11. 77 FR 19071 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-03-30

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... directive (AD) for certain Airbus Model A330-200, A330-300, A340-500, and A340-600 series airplanes. This AD...: During structural part assembly in Airbus production line, some nuts Part Number (P/N) ASNA2531-4 were...

  12. 78 FR 69594 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-11-20

    ...-0972; Directorate Identifier 2002-NM-009-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes... airworthiness directive (AD) for all Airbus Model A330 series airplanes. The NPRM would have required... rulemaking (NPRM) for a new AD for all Airbus Model A330 series airplanes. The NPRM, FAA Docket No. FAA-2013...

  13. 77 FR 26998 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2012-05-08

    ...-0428; Directorate Identifier 2011-NM-078-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-243, -243F, -342..., between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For Airbus service information...

  14. 30 CFR 256.71 - Directional drilling.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Directional drilling. 256.71 Section 256.71... drilling. In accordance with an approved exploration plan or development and production plan, a lease may be maintained in force by directional wells drilled under the leased area from surface locations on...

  15. Direction of Wording Effects in Balanced Scales.

    Science.gov (United States)

    Miller, Timothy R.; Cleary, T. Anne

    1993-01-01

    The degree to which statistical item selection reduces direction-of-wording effects in balanced affective measures developed from relatively small item pools was investigated with 171 male and 228 female undergraduate and graduate students at 2 U.S. universities. Clearest direction-of-wording effects result from selection of items with high…

  16. Memoization in Type-Directed Partial Evaluation

    DEFF Research Database (Denmark)

    Balat, Vincent; Danvy, Olivier

    2002-01-01

    the functions and type-directed partial evaluation provides a convenient setting to obtain the normal form of their composition. However, off-the-shelf type-directed partial evaluation turns out to yield gigantic normal forms. We identify that this gigantism is due to redundancies, and that these redundancies...

  17. Stigma and Schizophrenia: Directions in Student Training

    Science.gov (United States)

    Mason, Susan E.; Miller, Rachel

    2006-01-01

    The persistence of stigma related to schizophrenia is addressed as a continuing challenge for social work students working in mental health. Student education is best grounded in direct clinical work with clients in conjunction with field supervision and classroom education. Through direct practice in individual and group sessions, students learn…

  18. NASA directives: Master list and index

    Science.gov (United States)

    1994-01-01

    This Handbook sets forth in two parts the following information for the guidance of users of the NASA Management Directives System. Chapter 1 contains introductory information material on how to use this Handbook. Chapter 2 is a complete master list of Agency-wide management directives, describing each directive by type, number, effective date, expiration date, title, and organization code of the office responsible for the directive. Chapter 3 includes a consolidated numerical list of all delegations of authority and a breakdown of such delegation by the office of Installation to which special authority is assigned. Chapter 4 sets forth a consolidated list of all NASA Handbooks (NHB's) and important footnotes covering the control and ordering of such documents. Chapter 5 is a consolidated list of NASA management directives applicable to the Jet Propulsion Laboratory. Chapter 6 is a consolidated list of NASA management directives published in the code of Federal Regulations. Complementary manuals to the NASA Management Directives System are described in Chapter 7. Part B contains an in-depth alphabetical index to all NASA management directives other than Handbooks.

  19. 5 CFR 330.402 - Direct recruitment.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Direct recruitment. 330.402 Section 330.402 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, SELECTION, AND PLACEMENT (GENERAL) Positions Restricted to Preference Eligibles § 330.402 Direct recruitment...

  20. Direct photon production and PDF fits reloaded

    NARCIS (Netherlands)

    Campbell, John M.; Rojo, Juan; Slade, Emma; Williams, Ciaran

    2018-01-01

    Direct photon production in hadronic collisions provides a handle on the gluon PDF by means of the QCD Compton scattering process. In this work we revisit the impact of direct photon production on a global PDF analysis, motivated by the recent availability of the next-to-next-to-leading (NNLO)

  1. 48 CFR 31.202 - Direct costs.

    Science.gov (United States)

    2010-10-01

    ... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 31.202 Direct... amount as an indirect cost if the accounting treatment— (1) Is consistently applied to all final cost... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Direct costs. 31.202...

  2. Direct speech constructions in aphasic Dutch narratives

    NARCIS (Netherlands)

    Groenewold, Rimke; Bastiaanse, Roelien; Huiskes, Mike

    2013-01-01

    Background: Previous studies have shown that individuals with aphasia are usually able to produce direct reported speech constructions. So far these studies have mainly been conducted in English. The results show that direct speech is beneficial for aphasic speakers for various reasons. In Dutch the

  3. 12 CFR 567.4 - Capital directives.

    Science.gov (United States)

    2010-01-01

    ... requirement, the leverage ratio requirement, the tangible capital requirement, or individual minimum capital... capital directive, it may become effective immediately. A capital directive shall remain in effect and... plan shall continue in full force and effect. (b) Relation to other administrative actions. The Office...

  4. 24 CFR 9.131 - Direct threat.

    Science.gov (United States)

    2010-04-01

    ... health or safety of others. (b) “Direct threat” means a significant risk to the health or safety of... provision of auxiliary aids or services. (c) In determining whether an individual poses a direct threat to the health or safety of others, the agency must make an individualized assessment, based on reasonable...

  5. 12 CFR 619.9135 - Direct lender.

    Science.gov (United States)

    2010-01-01

    ... and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM DEFINITIONS § 619.9135 Direct lender. The term direct lender refers to Farm Credit banks and associations (production credit associations, agricultural credit associations, and Federal land credit associations) authorized to lend to eligible...

  6. Advance directives: survey of primary care patients.

    Science.gov (United States)

    O'Sullivan, Rory; Mailo, Kevin; Angeles, Ricardo; Agarwal, Gina

    2015-04-01

    To establish the prevalence of patients with advance directives in a family practice, and to describe patients' perspectives on a family doctor's role in initiating discussions about advance directives. A self-administered patient questionnaire. A busy urban family medicine teaching clinic in Hamilton, Ont. A convenience sample of adult patients attending the clinic over the course of a typical business week. The prevalence of advance directives in the patient population was determined, and the patients' expectations regarding the role of their family doctors were elucidated. The survey population consisted of 800 participants (a response rate of 72.5%) well distributed across age groups; 19.7% had written advance directives and 43.8% had previously discussed the topic of advance directives, but only 4.3% of these discussions had occurred with family doctors. In 5.7% of cases, a family physician had raised the issue; 72.3% of respondents believed patients should initiate the discussion. Patients who considered advance directives extremely important were significantly more likely to want their family doctors to start the conversation (odds ratio 3.98; P < .05). Advance directives were not routinely addressed in the family practice. Most patients preferred to initiate the discussion of advance directives. However, patients who considered the subject extremely important wanted their family doctors to initiate the discussion. Copyright© the College of Family Physicians of Canada.

  7. Apparent directional selection by biased pleiotropic mutation.

    Science.gov (United States)

    Tanaka, Yoshinari

    2010-07-01

    Pleiotropic effects of deleterious mutations are considered to be among the factors responsible for genetic constraints on evolution by long-term directional selection acting on a quantitative trait. If pleiotropic phenotypic effects are biased in a particular direction, mutations generate apparent directional selection, which refers to the covariance between fitness and the trait owing to a linear association between the number of mutations possessed by individuals and the genotypic values of the trait. The present analysis has shown how the equilibrium mean value of the trait is determined by a balance between directional selection and biased pleiotropic mutations. Assuming that genes act additively both on the trait and on fitness, the total variance-standardized directional selection gradient was decomposed into apparent and true components. Experimental data on mutation bias from the bristle traits of Drosophila and life history traits of Daphnia suggest that apparent selection explains a small but significant fraction of directional selection pressure that is observed in nature; the data suggest that changes induced in a trait by biased pleiotropic mutation (i.e., by apparent directional selection) are easily compensated for by (true) directional selection.

  8. 78 FR 28159 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-05-14

    ...-0418; Directorate Identifier 2012-NM-200-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 series airplanes; Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300 C4-605R Variant F airplanes...

  9. 78 FR 46543 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-08-01

    ...-0665; Directorate Identifier 2012-NM-082-AD] RIN 2120-AA64 Airworthiness Directives; Airbus Airplanes...: We propose to adopt a new airworthiness directive (AD) for all Airbus Model A330-300 series airplanes and Model A340-200 and -300 series airplanes. This proposed AD was prompted by reports of corrosion...

  10. Direct Reading Instruction and the NYS ELA

    Science.gov (United States)

    Jones-Carey, Margaret H.

    2013-01-01

    This study analyzed the impact of classroom based reading instruction ("direct instruction") on the standardized test scores of 6th grade students as measured by the New York State English Language Arts assessment (NYS ELA). It was hypothesized that the implementation of direct instruction in reading in grade 6 would improve NYS ELA…

  11. Early Studies of Binocular and Binaural Directions

    Directory of Open Access Journals (Sweden)

    Nicholas J. Wade

    2018-03-01

    Full Text Available Understanding how the eyes work together to determine the direction of objects provided the impetus for examining integration of signals from the ears to locate sounds. However, the advantages of having two eyes were recorded long before those for two ears were appreciated. In part, this reflects the marked differences in how we can compare perception with one or two organs. It is easier to close one eye and examine monocular vision than to “close” one ear and study monaural hearing. Moreover, we can move our eyes either in the same or in opposite directions, but humans have no equivalent means of moving the ears in unison. Studies of binocular single vision can be traced back over two thousand years and they were implicitly concerned with visual directions from each eye. The location of any point in visual or auditory space can be described by specifying its direction and distance, from the vantage point of an observer. From the late 18th century experiments indicated that binocular direction involved an eye movement component and experimental studies of binaural direction commenced slightly later. However, these early binocular and binaural experiments were not incorporated into theoretical accounts until almost a century later. The early history of research on visual direction with two eyes is contrasted to that on auditory direction with two ears.

  12. Smallish foreign direct investment, sluggish growth: Can ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Smallish foreign direct investment, sluggish growth: Can MERCOSUR do better? 08 décembre 2010. Edgard Rodriguez. GGP One-pager series. Since the 1990s, foreign direct investment (FDI) has been on the rise worldwide. By 2008, the world's FDI flows amounted to about $1.7 trillion (although they are expected to go ...

  13. Silicon nanostructures produced by laser direct etching

    DEFF Research Database (Denmark)

    Müllenborn, Matthias; Dirac, Paul Andreas Holger; Petersen, Jon Wulff

    1995-01-01

    A laser direct-write process has been applied to structure silicon on a nanometer scale. In this process, a silicon substrate, placed in a chlorine ambience, is locally heated above its melting point by a continuous-wave laser and translated by high-resolution direct-current motor stages. Only...

  14. A novel Direct Small World network model

    Directory of Open Access Journals (Sweden)

    LIN Tao

    2016-10-01

    Full Text Available There is a certain degree of redundancy and low efficiency of existing computer networks.This paper presents a novel Direct Small World network model in order to optimize networks.In this model,several nodes construct a regular network.Then,randomly choose and replot some nodes to generate Direct Small World network iteratively.There is no change in average distance and clustering coefficient.However,the network performance,such as hops,is improved.The experiments prove that compared to traditional small world network,the degree,average of degree centrality and average of closeness centrality are lower in Direct Small World network.This illustrates that the nodes in Direct Small World networks are closer than Watts-Strogatz small world network model.The Direct Small World can be used not only in the communication of the community information,but also in the research of epidemics.

  15. Novel Random Mutagenesis Method for Directed Evolution.

    Science.gov (United States)

    Feng, Hong; Wang, Hai-Yan; Zhao, Hong-Yan

    2017-01-01

    Directed evolution is a powerful strategy for gene mutagenesis, and has been used for protein engineering both in scientific research and in the biotechnology industry. The routine method for directed evolution was developed by Stemmer in 1994 (Stemmer, Proc Natl Acad Sci USA 91, 10747-10751, 1994; Stemmer, Nature 370, 389-391, 1994). Since then, various methods have been introduced, each of which has advantages and limitations depending upon the targeted genes and procedure. In this chapter, a novel alternative directed evolution method which combines mutagenesis PCR with dITP and fragmentation by endonuclease V is described. The kanamycin resistance gene is used as a reporter gene to verify the novel method for directed evolution. This method for directed evolution has been demonstrated to be efficient, reproducible, and easy to manipulate in practice.

  16. Direct-to-consumer advertising of pharmaceuticals.

    Science.gov (United States)

    Gellad, Ziad F; Lyles, Kenneth W

    2007-06-01

    Since the US Food and Drug Administration (FDA) released new guidelines on broadcast direct-to-consumer advertising in 1997, the prevalence of direct-to-consumer advertising of prescription drugs has increased exponentially. The impact on providers, patients, and the health care system is varied and dynamic, and the rapid changes in the last several years have markedly altered the health care landscape. To continue providing optimal medical care, physicians and other health care providers must be able to manage this influence on their practice, and a more thorough understanding of this phenomenon is an integral step toward this goal. This review will summarize the history of direct-to-consumer drug advertisements and the current regulations governing them. It will summarize the evidence concerning the impact of direct-to-consumer advertising on the public, providers, and the health care system, and conclude with observations regarding the future of direct-to-consumer advertising.

  17. Finding Direction in the Search for Selection.

    Science.gov (United States)

    Thiltgen, Grant; Dos Reis, Mario; Goldstein, Richard A

    2017-01-01

    Tests for positive selection have mostly been developed to look for diversifying selection where change away from the current amino acid is often favorable. However, in many cases we are interested in directional selection where there is a shift toward specific amino acids, resulting in increased fitness in the species. Recently, a few methods have been developed to detect and characterize directional selection on a molecular level. Using the results of evolutionary simulations as well as HIV drug resistance data as models of directional selection, we compare two such methods with each other, as well as against a standard method for detecting diversifying selection. We find that the method to detect diversifying selection also detects directional selection under certain conditions. One method developed for detecting directional selection is powerful and accurate for a wide range of conditions, while the other can generate an excessive number of false positives.

  18. Boosters and barriers for direct cardiac reprogramming.

    Science.gov (United States)

    Talkhabi, Mahmood; Zonooz, Elmira Rezaei; Baharvand, Hossein

    2017-06-01

    Heart disease is currently the most significant cause of morbidity and mortality worldwide, which accounts for approximately 33% of all deaths. Recently, a promising and alchemy-like strategy has been developed called direct cardiac reprogramming, which directly converts somatic cells such as fibroblasts to cardiac lineage cells such as cardiomyocytes (CMs), termed induced CMs or iCMs. The first in vitro cardiac reprogramming study, mediated by cardiac transcription factors (TFs)-Gata4, Tbx5 and Mef2C-, was not enough efficient to produce an adequate number of fully reprogrammed, functional iCMs. As a result, numerous combinations of cardiac TFs exist for direct cardiac reprogramming of mouse and human fibroblasts. However, the efficiency of direct cardiac reprogramming remains low. Recently, a number of cellular and molecular mechanisms have been identified to increase the efficiency of direct cardiac reprogramming and the quality of iCMs. For example, microgrooved substrate, cardiogenic growth factors [VEGF, FGF, BMP4 and Activin A], and an appropriate stoichiometry of TFs boost the direct cardiac reprogramming. On the other hand, serum, TGFβ signaling, activators of epithelial to mesenchymal transition, and some epigenetic factors (Bmi1 and Ezh2) are barriers for direct cardiac reprogramming. Manipulating these mechanisms by the application of boosters and removing barriers can increase the efficiency of direct cardiac reprogramming and possibly make iCMs reliable for cell-based therapy or other potential applications. In this review, we summarize the latest trends in cardiac TF- or miRNA-based direct cardiac reprogramming and comprehensively discuses all molecular and cellular boosters and barriers affecting direct cardiac reprogramming. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. FOREIGN DIRECT INVESTMENTS DURING FINANCIAL CRISES

    Directory of Open Access Journals (Sweden)

    VINTILA DENISIA MARIANA

    2011-12-01

    Full Text Available The fundamental idea of International capital flows is that short-term flows can be easily reversed, while flows on a longer time horizon are more stable. Crises are associated with withdrawals of short-term capital flows and growth of the foreign direct investment flows. The current crisis has meant a major decline of international capital flows, also of the foreign direct investment. The analysis in this article tries to establish if and under which conditions foreign direct investments can bring greater stability during the crisis, comparing the evolution of foreign direct investments in the current crisis with their response in previous crises. We show that during previous crises foreign direct investments were stable, behaving differently from other types of capital. Yet, during the current crisis, foreign direct investments have proven to be not so stable and all the components declined, raising questions about the resumption of the positive trend. The stability of foreign direct investments in the past was given by the increase of mergers and acquisitions during the crisis, reflecting fire-sale FDI. This feature is not found in the current crisis as mergers and acquisitions were severe affected by the crises and recorded a major decline. The current paper is realized in the doctoral program entitled PhD in economics at the standards of European knowledge- DoEsEc, scientific coordinator Prof. PhD Rodica Zaharia, institution The Academy of Economic Studies Bucharest, Faculty of International Business, period of research 2009-2012.

  20. Use of direct marketing in nonprofit organizations

    Directory of Open Access Journals (Sweden)

    Popović Ana

    2010-01-01

    Full Text Available Non profit organizations represent very heterogenus group of organizations which can be determined by the fact that they are being used as forums for creation and distribution of new ideas. Their aim is to raise public awareness on the purpose they promote and get the reply for their initiatives for gaining support in form of monetary sources for charities, vote for political candidate or achieving a communicational goal. Non governmental organizations, as the dominant form of non profit organizations, are being founded with mission to raise public awareness on some issue or provide help to certain marginalized group. The direct marketing instruments and techniques are considered to be very useful for achieving mission formulated that way. They are, by their nature, precisely targeted and objective-oriented and require direct reply. Apart from that, direct marketing activities are cost-efficient, costs that they generate can be shown in financial reports, and results of undertaken initiatives are directly measurable. All the mentioned lead to conclusion that direct marketing is, for additional reasons, even more appropriate for NPOs having in mind that they usually have limited available resources. In the relevant literature two main roles of direct marketing in non profit organizations are mentioned - managing relations with representatives of stakeholder groups and fundraising. In this paper, therefore, after the facts referring functioning of NPOs, direct marketing strategies used for mentioned purposes will be presented consequently.

  1. Personalized direct marketing using digital publishing

    Science.gov (United States)

    Kutty, Cheeniyil L.; Prabhakaran, Jayasree K.

    2006-02-01

    In today's cost-conscious business climate, marketing and customer service decision makers are increasingly concerned with how to increase customer response and retention rates. Companies spend large amounts of money on Customer Relationship Management (CRM) solutions and data acquisition but they don't know how to use the information stored in these systems to improve the effectiveness of their direct marketing campaigns. By leveraging the customer information they already have, companies can create personalized, printed direct mail programs that generate high response rates, greater returns, and stronger customer loyalty, while gaining a significant edge over their competitors. To reach the promised land of one-to-one direct marketing (personalized direct marketing - PDM), companies need an end-to-end solution for creating, managing, printing, and distributing personalized direct mail "on demand." Having access to digital printing is just one piece of the solution. A more complete approach includes leveraging personalization technology into a useful direct marketing tool that provides true one-to-one marketing, allowing variable images and text in a personalized direct mail. This paper discusses integration of CRM with a Print-on-Demand solution so as to create truly personalized printed marketing campaigns for one or many individuals based on the profile information, preferences and purchase history stored in the CRM.

  2. TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING

    Science.gov (United States)

    Longhurst, G.E.

    1961-07-11

    A two-direction motion bearing which is incorporated in a refueling nuclear fuel element trsnsfer tool assembly is described. A plurality of bi- directional bearing assembliesare fixed equi-distantly about the circumference of the transfer tool assembly to provide the tool assembly with a bearing surface- for both axial and rotational motion. Each bi-directional bearing assembly contains a plurality of circumferentially bulged rollers mounted in a unique arrangement which will provide a bearing surface for rotational movement of the tool assembly within a bore. The bi-direc tional bearing assembly itself is capable of rational motion and thus provides for longitudinal movement of the tool assembly.

  3. Configuring NIF for direct drive experiments

    International Nuclear Information System (INIS)

    Eimerl, D.; Rothenberg, J.; Key, M.

    1995-01-01

    The National Ignition Facility (NIF) is a proposed 1.8 MJ laser facility for carrying out experiments in inertial confinement fusion, currently designed for indirect drive experiments. The direct drive approach is being pursued at the 30 kJ Omega facility at the University of Rochester. In this paper we discuss the modifications to the NIF laser that would be required for both indirect and direct drive experiments. A primary concern is the additional cost of adding direct drive capability to the facility

  4. Enhancing Scalability of Sparse Direct Methods

    International Nuclear Information System (INIS)

    Li, Xiaoye S.; Demmel, James; Grigori, Laura; Gu, Ming; Xia, Jianlin; Jardin, Steve; Sovinec, Carl; Lee, Lie-Quan

    2007-01-01

    TOPS is providing high-performance, scalable sparse direct solvers, which have had significant impacts on the SciDAC applications, including fusion simulation (CEMM), accelerator modeling (COMPASS), as well as many other mission-critical applications in DOE and elsewhere. Our recent developments have been focusing on new techniques to overcome scalability bottleneck of direct methods, in both time and memory. These include parallelizing symbolic analysis phase and developing linear-complexity sparse factorization methods. The new techniques will make sparse direct methods more widely usable in large 3D simulations on highly-parallel petascale computers

  5. High precision studies of directional correlations

    International Nuclear Information System (INIS)

    El-khosht, M.

    1980-01-01

    Two applications of the method of directional correlations are described. The first part deals with gamma-gamma directional correlations measurements. A total of 27 cascades have been studied in 97 Tc, 206 Pb and 206 Bi. Information is obtained on the angular momenta of levels, multipolarities of electromagnetic transitions and further, reduced transition probabilities. The later part of this thesis describes a determination of anisotropic directional correlation between gamma-rays and LX-rays in 160 Dy. To the authors' knowledge this is the first observation of an anisotropic correlation between gamma rays and X-rays following internal conversion. (Auth.)

  6. Chaotic inflation in models with flat directions

    International Nuclear Information System (INIS)

    Graziani, F.; Olive, K.

    1989-01-01

    We consider the chaotic inflationary scenario in models with flat directions. We find that unless the scalars along the flat directions have vacuum expectation values p or 10 14 M p 15 M p depending on the expectation values of the chaotic inflator, Ψ, one or two or more periods of inflation occur but with a resulting energy density perturbation δρ/ρ ≅ 10 -16 , far too small to be of any consequence for galaxy formation. Even with p only limited initial values of ≅ (3-200) M p result in inflation with reasonable density perturbations. Thus chaotic inflation in models with flat directions require rather special initial conditions. (orig.)

  7. International food aid – directions of changes

    Directory of Open Access Journals (Sweden)

    Agnieszka Sapa

    2012-04-01

    Full Text Available Permanently unsolved world food insecurity problem makes the international community search for solutions. One of the used methods is international food aid directed to developing countries. Long term analyses of the food aid flows allow to identify some tendencies that show: increase of emergency food aid and decrease of direct transfer. These tendencies also apply to the two biggest food donors i.e. the USA and the EU. The noticeable directions of changes are based on the international community initiatives, on which the national regulation are formed later.

  8. Thermal imitators with single directional invisibility

    Science.gov (United States)

    Wang, Ruizhe; Xu, Liujun; Huang, Jiping

    2017-12-01

    Thermal metamaterials have been intensively studied during the past years to achieve the long-standing dream of invisibility, illusion, and other inconceivable thermal phenomena. However, many thermal metamaterials can only exhibit omnidirectional thermal response, which take on the distinct feature of geometrical isotropy. In this work, we theoretically design and experimentally fabricate a pair of thermal imitators by applying geometrical anisotropy provided by elliptical/ellipsoidal particles and layered structures. This pair of thermal imitators possesses thermal invisibility in one direction, while having thermal opacity in other directions. This work may open a gate in designing direction-dependent thermal metamaterials.

  9. Direct Democracy in Local Politics in Denmark

    DEFF Research Database (Denmark)

    Svensson, Palle

    2007-01-01

    Elements of  direct democracy at the local level does exist in Denmark, but it is little known, because no formal rules regulate this aspect of political life, because results from popular initiatives and referendums are not recorded in official statistics, and because few systematic analyses have...... been published. This paper, accordingly, has an explorative nature and asks two basic questions: What is the current state of direct democracy at the local level in Denmark, and what are the prospects for a further development of direct democracy at the local level in Denmark? The paper is based...

  10. The New EU Public Procurement Directives

    DEFF Research Database (Denmark)

    , transparency requirements, competitive dialogue, framework agreements, use of social and environmental criteria, Partnering and Public Private Partnerships and concessions. This book contains contributions based on presentations given by a number of the international and Danish speakers at the conference.......31 March 2004 the EU adopted two new public procurement directives: one for the public sector (2004/18/EC) and one for utilities (2004/17/EC). The new directives aim at simplification and modernisation of the previously existing directives including adaptation to electronic purchasing techniques...

  11. Direct magnification radiography of the hand

    International Nuclear Information System (INIS)

    Presacco, D.; Pellegrini, A.; Di Maggio, C.

    1987-01-01

    The value of direct magnification radiography of the hand and the wrist has been studied in 128 patients affected by rheumatic diseases. Only in a small group (3.17%) magnification determined a higher percentage of correct diagnosis; in the 17.06% of cases direct magnification radiography provided useful increase in information but did not change the diagnisis correctly reached by conventional techniques. In most cases (79.76%) magnification provided only a better image quality but no more information helpful for the diagnosis, because of the high level achieved by convetional techniques. Therefore direct magnification radiography must be used only in selected cases and not as routine radiographyc technique

  12. FORMS AND MOTIVATIONS OF FOREIGN DIRECT INVESTMENT

    Directory of Open Access Journals (Sweden)

    Maria-Ramona SÂRBU

    2014-04-01

    Full Text Available This study proposes the identification of forms of Foreign Direct Investment (FDI and analyzes factors influencing FDI motivation. Designing a coherent program to encourage foreign direct investment is based on knowledge of the factors that determine international companies to resort to this type of development: these companies resort to foreign direct investment if they have ownership advantages and internationalization, while another country has locational advantages to the company's home country. Thus, identifying the factors that influence the motivation of FDI is important both at the microeconomic level, local, local authorities and macroeconomic, national, government to develop measures for multiplying FDI .

  13. DETERMINANTS OF FOREIGN DIRECT INVESTMENTS IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Lenuta CARP (CEKA

    2014-11-01

    Full Text Available Foreign direct investments have known an increased importance in the worldwide economy. Theoretical approaches highlight the positive externalities foreign direct investments generate in the beneficiary economy though different channels. The aim of this paper is to emphasize, based on an econometric analysis using data for Romania, the fundamental determinants of foreign direct investments attractiveness. The analysis will be followed by the recommendations for increasing the inflows in our country and measures to enhance their effect in the national economy. Further analysis will be developed focusing on the emerging countries from Europe using a panel technique.

  14. Direct marketing and market communication process

    Directory of Open Access Journals (Sweden)

    Jovović Sanja

    2007-01-01

    Full Text Available Direct marketing is marketing which demands immediate reply. That reply can be an order, a request for an additional information, a registration, a telephone call or a visit. This work presents direct marketing as the most contemporary method of company communications with environs. A concept of direct marketing is made and aimed for complete identification of existing customers and for finding out potential customers. Mail, printed documents e-mail and new medias are used as modern communications channels. It is especially emphasizes the Internet as an important media.

  15. Directional velocity estimation using focusing along the flow direction - I: Theory and simulation

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2003-01-01

    A new method for directional velocity estimation is presented. The method uses beamformation along the flow direction to generate data in which the correct velocity magnitude can be directly estimated from the shift in position of the received consecutive signals. The shift is found by cross-corr...

  16. Directional Tuning Curves, Elementary Movement Detectors, and the Estimation of the Direction of Visual Movement

    NARCIS (Netherlands)

    Hateren, J.H. van

    1990-01-01

    Both the insect brain and the vertebrate retina detect visual movement with neurons having broad, cosine-shaped directional tuning curves oriented in either of two perpendicular directions. This article shows that this arrangement can lead to isotropic estimates of the direction of movement: for any

  17. Directional output distance functions: endogenous directions based on exogenous normalization constraints

    Science.gov (United States)

    In this paper we develop a model for computing directional output distance functions with endogenously determined direction vectors. We show how this model is related to the slacks-based directional distance function introduced by Fare and Grosskopf and show how to use the slacks-based function to e...

  18. Directional Scanning as a Function of Stimulus Characteristics, Reading Habits, and Directional Set

    Science.gov (United States)

    Nachshon, Israel; And Others

    1977-01-01

    "32 English readers and 32 Hebrew readers were shown stimuli with directional characteristics (English and Hebrew letters) and stimuli with no directional characteristics (arrays of different circles, bars, colors, and geometric figures) for scanning. The results showed that, while directional stimulus characteristics affected the direction…

  19. Direct conversion of nuclear energy into radiation: New direction in thermonuclear laser fusion

    International Nuclear Information System (INIS)

    Babaev, Yu.N.; Vedenov, A.A.; Filyukov, A.A.

    1995-01-01

    In investigations dealing with thermonuclear fusion, a radical new direction appeared some time ago, namely the direct conversion of nuclear and thermonuclear energy into radiation energy. This paper reviews early work on this topic in Russia and the United States and discusses some recent new directions

  20. [Small scale direct oxide reduction (DOR) experiments

    International Nuclear Information System (INIS)

    1987-01-01

    Objectives were to provide process design information to the Plutonium Recovery Project and to produce DOR (direct oxide reduction) product which meets Foundry purity specifications and Oh-0 Foundry specifications

  1. Bidirectional communication using delay coupled chaotic directly ...

    Indian Academy of Sciences (India)

    Corresponding author. ... 30 September 2009. Abstract. Chaotic synchronization of two directly modulated semiconductor lasers with ... For InGaAsP lasers used in optical communication systems, the nonlinear gain re- duction is very strong and its ...

  2. THE MISNOMERS OF SPIRITUAL 'DIRECTING' AND 'COACHING'

    African Journals Online (AJOL)

    organisational context through said ways of interaction. As such, the focus .... While coaching can and certainly is practised from an instructional or directive ..... pressures or motivators such as self‑esteem and quality of life (Knowles et al.

  3. Directed forgetting: Comparing pictures and words.

    Science.gov (United States)

    Quinlan, Chelsea K; Taylor, Tracy L; Fawcett, Jonathan M

    2010-03-01

    The authors investigated directed forgetting as a function of the stimulus type (picture, word) presented at study and test. In an item-method directed forgetting task, study items were presented 1 at a time, each followed with equal probability by an instruction to remember or forget. Participants exhibited greater yes-no recognition of remember than forget items for each of the 4 study-test conditions (picture-picture, picture-word, word-word, word-picture). However, this difference was significantly smaller when pictures were studied than when words were studied. This finding demonstrates that the magnitude of the directed forgetting effect can be reduced by high item memorability, such as when the picture superiority effect is operating. This suggests caution in using pictures at study when the goal of an experiment is to examine potential group differences in the magnitude of the directed forgetting effect. 2010 APA, all rights reserved.

  4. Directional Transverse Oscillation Vector Flow Estimation

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2017-01-01

    A method for estimating vector velocities using transverse oscillation (TO) combined with directional beamforming is presented. In Directional Transverse Oscillation (DTO) a normal focused field is emitted and the received signals are beamformed in the lateral direction transverse to the ultrasound...... beam to increase the amount of data for vector velocity estimation. The approach is self-calibrating as the lateral oscillation period is estimated from the directional signal through a Fourier transform to yield quantitative velocity results over a large range of depths. The approach was extensively...... simulated using Field IIpro and implemented on the experimental SARUS scanner in connection with a BK Medical 8820e convex array transducer. Velocity estimates for DTO are found for beam-to-flow angles of 60, 75, and 90, and vessel depths from 24 to 156 mm. Using 16 emissions the Standard Deviation (SD...

  5. A three-port direct current converter

    DEFF Research Database (Denmark)

    2016-01-01

    circuit comprises a connection between the at least one input direct current source and the at least one storage battery, the primary side circuit configured for operating as a buck converter; a second magnetic component serially coupled to the first single magnetic component, wherein the first and second...... magnetic components are configured to perform a voltage step-up, wherein the secondary side circuit comprises a connection between the at least one storage battery and at least one load, the secondary side configured for operating as a tapped boost converter; wherein the three-port direct current converter......The three-port direct current converter comprising: at least one input direct current source; at least one storage battery; a primary side circuit; a secondary side circuit; a first single magnetic component shared by the primary side circuit and the secondary side circuit, wherein the primary side...

  6. Maximizing Lumen Gain With Directional Atherectomy.

    Science.gov (United States)

    Stanley, Gregory A; Winscott, John G

    2016-08-01

    To describe the use of a low-pressure balloon inflation (LPBI) technique to delineate intraluminal plaque and guide directional atherectomy in order to maximize lumen gain and achieve procedure success. The technique is illustrated in a 77-year-old man with claudication who underwent superficial femoral artery revascularization using a HawkOne directional atherectomy catheter. A standard angioplasty balloon was inflated to 1 to 2 atm during live fluoroscopy to create a 3-dimensional "lumenogram" of the target lesion. Directional atherectomy was performed only where plaque impinged on the balloon at a specific fluoroscopic orientation. The results of the LPBI technique were corroborated with multimodality diagnostic imaging, including digital subtraction angiography, intravascular ultrasound, and intra-arterial pressure measurements. With the LPBI technique, directional atherectomy can routinely achieve <10% residual stenosis, as illustrated in this case, thereby broadly supporting a no-stent approach to lower extremity endovascular revascularization. © The Author(s) 2016.

  7. Directional outlyingness for multivariate functional data

    KAUST Repository

    Dai, Wenlin

    2018-04-07

    The direction of outlyingness is crucial to describing the centrality of multivariate functional data. Motivated by this idea, classical depth is generalized to directional outlyingness for functional data. Theoretical properties of functional directional outlyingness are investigated and the total outlyingness can be naturally decomposed into two parts: magnitude outlyingness and shape outlyingness which represent the centrality of a curve for magnitude and shape, respectively. This decomposition serves as a visualization tool for the centrality of curves. Furthermore, an outlier detection procedure is proposed based on functional directional outlyingness. This criterion applies to both univariate and multivariate curves and simulation studies show that it outperforms competing methods. Weather and electrocardiogram data demonstrate the practical application of our proposed framework.

  8. Electromagnetic fields: the new European directive

    International Nuclear Information System (INIS)

    Moureaux, Patrick

    2014-01-01

    A European directive is specifying the thresholds for exposure to electromagnetic fields. The risk assessment approach proposed should enable worker health to be taken better into account. An overview of the new provisions. (author)

  9. Center for Direct Reading and Sensor Technologies

    Data.gov (United States)

    Federal Laboratory Consortium — Direct-reading methods and sensors are being used more frequently in many different settings ranging from personal monitoring of individual health to applications in...

  10. Construction engineering inspection direct cost survey.

    Science.gov (United States)

    2014-07-01

    The objective of the study was to provide a rationale to Georgia Department of Transportation : (GDOT) for Direct Costs in terms of salary and wages charged by qualified independent : contractors performing Construction Engineering Inspection (CEI) s...

  11. Interference management using direct sequence spread spectrum ...

    African Journals Online (AJOL)

    Interference management using direct sequence spread spectrum (DSSS) technique ... Journal of Fundamental and Applied Sciences ... Keywords: DSSS, LTE network; Wi-Fi network; SINR; interference management and interference power.

  12. A Directed Signature Scheme and its Applications

    OpenAIRE

    Lal, Sunder; Kumar, Manoj

    2004-01-01

    This paper presents a directed signature scheme with the property that the signature can be verified only with the help of signer or signature receiver. We also propose its applications to share verification of signatures and to threshold cryptosystems.

  13. Electronegative Gas Thruster - Direct Thrust Measurement

    Data.gov (United States)

    National Aeronautics and Space Administration — This effort is an international collaboration and academic partnership to mature an innovative electric propulsion (EP) thruster concept to TRL 3 through direct...

  14. Direct ophthalmoscopy on YouTube

    DEFF Research Database (Denmark)

    Borgersen, Nanna Jo; Henriksen, Mikael Johannes Vuokko; Konge, Lars

    2016-01-01

    BACKGROUND: Direct ophthalmoscopy is well-suited for video-based instruction, particularly if the videos enable the student to see what the examiner sees when performing direct ophthalmoscopy. We evaluated the pedagogical effectiveness of instructional YouTube videos on direct ophthalmoscopy...... in general. We then systematically searched YouTube. Two authors reviewed eligible videos to assess eligibility and extract data on video statistics, content, and approach to visualization. Correlations between video statistics and contents were investigated using two-tailed Spearman's correlation. RESULTS...... the patient and how to examine the fundus. Time spent on fundus examination correlated with the number of views per week (Spearman's ρ=0.53; P=0.029). CONCLUSION: Videos may help overcome the pedagogical issues in teaching direct ophthalmoscopy; however, the few available videos on YouTube fail to address...

  15. Statistics of wind direction and its increments

    International Nuclear Information System (INIS)

    Doorn, Eric van; Dhruva, Brindesh; Sreenivasan, Katepalli R.; Cassella, Victor

    2000-01-01

    We study some elementary statistics of wind direction fluctuations in the atmosphere for a wide range of time scales (10 -4 sec to 1 h), and in both vertical and horizontal planes. In the plane parallel to the ground surface, the direction time series consists of two parts: a constant drift due to large weather systems moving with the mean wind speed, and fluctuations about this drift. The statistics of the direction fluctuations show a rough similarity to Brownian motion but depend, in detail, on the wind speed. This dependence manifests itself quite clearly in the statistics of wind-direction increments over various intervals of time. These increments are intermittent during periods of low wind speeds but Gaussian-like during periods of high wind speeds. (c) 2000 American Institute of Physics

  16. Vital directions for mathematics education research

    CERN Document Server

    Leatham, Keith R

    2013-01-01

    In this book, experts discuss vital issues in mathematics education and what they see as viable directions for research in mathematics education to address them. Their recommendations take the form of overarching principles and ideas that cut across the field.

  17. Deregulation and Macroeconomic Drivers Of Foreign Direct ...

    African Journals Online (AJOL)

    Deregulation and Macroeconomic Drivers Of Foreign Direct Investment In Nigerian Agriculture (1970 -2009): An Econometric Analysis. ... The study showed that foreign exchange and the economic deregulation policy of Nigerian government ...

  18. [Theological moral considerations of advance directives].

    Science.gov (United States)

    Virt, G

    1997-01-01

    The forms for advanced directives vary considerably in respect to content and wording. This article intends to develop ethical criteria for such texts, from the moraltheological point of view, also considering the social context.

  19. Spatially Refined Aerosol Direct Radiative Forcing Efficiencies

    Science.gov (United States)

    Global aerosol direct radiative forcing (DRF) is an important metric for assessing potential climate impacts of future emissions changes. However, the radiative consequences of emissions perturbations are not readily quantified nor well understood at the level of detail necessary...

  20. Embedment of Chlorpheniramine Maleate in Directly Compressed ...

    African Journals Online (AJOL)

    chlorpheniramine maleate (CPM) from its matrix tablets prepared by direct compression. Methods: Different ratios of compritol and kollidon SR (containing 50 % matrix component) in 1:1, 1:2, ... Magnesium stearate and hydrochloric acid were.

  1. Methods of conditioning direct methanol fuel cells

    Science.gov (United States)

    Rice, Cynthia; Ren, Xiaoming; Gottesfeld, Shimshon

    2005-11-08

    Methods for conditioning the membrane electrode assembly of a direct methanol fuel cell ("DMFC") are disclosed. In a first method, an electrical current of polarity opposite to that used in a functioning direct methanol fuel cell is passed through the anode surface of the membrane electrode assembly. In a second method, methanol is supplied to an anode surface of the membrane electrode assembly, allowed to cross over the polymer electrolyte membrane of the membrane electrode assembly to a cathode surface of the membrane electrode assembly, and an electrical current of polarity opposite to that in a functioning direct methanol fuel cell is drawn through the membrane electrode assembly, wherein methanol is oxidized at the cathode surface of the membrane electrode assembly while the catalyst on the anode surface is reduced. Surface oxides on the direct methanol fuel cell anode catalyst of the membrane electrode assembly are thereby reduced.

  2. Fabrication of LD-3 Polymer Directional Couplers

    National Research Council Canada - National Science Library

    Chen, Ray T

    1998-01-01

    .... LD-3 polymer directional couplers arc designed and fabricated to operate at 1.3 microns. Waveguide propagation losses, device characterization, demonstration of cross coupling and packaged device pictures are presented in this final report.

  3. Geothermal direct use engineering and design guidebook

    International Nuclear Information System (INIS)

    Lienau, P.J.; Lunis, B.C.

    1991-01-01

    The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States

  4. Direct reading fast microwave interferometer for EBT

    International Nuclear Information System (INIS)

    Uckan, T.

    1984-10-01

    A simple and inexpensive 4-mm direct reading fast (rise time approx. 100 μs) microwave interferometer is described. The system is particularly useful for density measurements on the ELMO Bumpy Torus (EBT) during pulsed operation

  5. DIRECTIONAL WELL TRAJECTORY DESIGN: THE THEORITICAL ...

    African Journals Online (AJOL)

    user

    2016-10-04

    Oct 4, 2016 ... record presentation of a desired complex directional well trajectory, also from which the overall angle change. (dogleg) is observed not to ... example; 23oNE means 23 degrees East from North, .... Azimuth Angles Selection.

  6. Direct Foreign Investment in the United Kingdom.

    Science.gov (United States)

    Hinde, Kevin

    1987-01-01

    Notes introductory undergraduate economics textbooks have no formal analysis of the rationale for direct foreign investment by multinational firms. Examines this area in an attempt to develop more content information for undergraduate courses. (RKM)

  7. 78 FR 78694 - Airworthiness Directives; Airbus Airplanes

    Science.gov (United States)

    2013-12-27

    ... Airworthiness Directives; Airbus Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... all Airbus Model A330-200 and -300 series airplanes, and Model A340-200 and -300 series airplanes. AD... certain check valves in the [[Page 78695

  8. Oriented collagen fibers direct tumor cell intravasation

    KAUST Repository

    Han, Weijing; Chen, Shaohua; Yuan, Wei; Fan, Qihui; Tian, Jianxiang; Wang, Xiaochen; Chen, Longqing; Zhang, Xixiang; Wei, Weili; Liu, Ruchuan; Qu, Junle; Jiao, Yang; Austin, Robert H.; Liu, Liyu

    2016-01-01

    that the local fiber alignment enhanced cell-ECM interactions. Specifically, metastatic MDA-MB-231 breast cancer cells followed the local fiber alignment direction during the intravasation into rigid Matrigel (∼10 mg/mL protein concentration).

  9. Iterative Adaptive Sampling For Accurate Direct Illumination

    National Research Council Canada - National Science Library

    Donikian, Michael

    2004-01-01

    This thesis introduces a new multipass algorithm, Iterative Adaptive Sampling, for efficiently computing the direct illumination in scenes with many lights, including area lights that cause realistic soft shadows...

  10. Geothermal direct use engineering and design guidebook

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.; Lunis, B.C. (eds.)

    1991-01-01

    The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating and cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of the resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental consideration. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very large potential in the United States.

  11. Geothermal direct use engineering and design guidebook

    Energy Technology Data Exchange (ETDEWEB)

    Bloomquist, R.G.; Culver, G.; Ellis, P.F.; Higbee, C.; Kindle, C.; Lienau, P.J.; Lunis, B.C.; Rafferty, K.; Stiger, S.; Wright, P.M.

    1989-03-01

    The Geothermal Direct Use Engineering and Design Guidebook is designed to be a comprehensive, thoroughly practical reference guide for engineers and designers of direct heat projects. These projects could include the conversion of geothermal energy into space heating cooling of buildings, district heating, greenhouse heating, aquaculture and industrial processing. The Guidebook is directed at understanding the nature of geothermal resources and the exploration of these resources, fluid sampling techniques, drilling, and completion of geothermal wells through well testing, and reservoir evaluation. It presents information useful to engineers on the specification of equipment including well pumps, piping, heat exchangers, space heating equipment, heat pumps and absorption refrigeration. A compilation of current information about greenhouse, aquaculture and industrial applications is included together with a discussion of engineering cost analysis, regulation requirements, and environmental considerations. The purpose of the Guidebook is to provide an integrated view for the development of direct use projects for which there is a very potential in the United States.

  12. Direct Optimal Control of Duffing Dynamics

    Science.gov (United States)

    Oz, Hayrani; Ramsey, John K.

    2002-01-01

    The "direct control method" is a novel concept that is an attractive alternative and competitor to the differential-equation-based methods. The direct method is equally well applicable to nonlinear, linear, time-varying, and time-invariant systems. For all such systems, the method yields explicit closed-form control laws based on minimization of a quadratic control performance measure. We present an application of the direct method to the dynamics and optimal control of the Duffing system where the control performance measure is not restricted to a quadratic form and hence may include a quartic energy term. The results we present in this report also constitute further generalizations of our earlier work in "direct optimal control methodology." The approach is demonstrated for the optimal control of the Duffing equation with a softening nonlinear stiffness.

  13. NRC TLD Direct Radiation Monitoring Network

    International Nuclear Information System (INIS)

    Struckmeyer, R.; McNamara, N.

    1991-12-01

    This report provides the status and results of the NRC Thermoluminescent Dosimeter (TLD) Direct Radiation Monitoring Network. It presents the radiation levels measured in the vicinity of NRC licensed facilities throughout the country for the third quarter of 1991

  14. Self-Directed Learning with Feedback

    Science.gov (United States)

    Choi, Youngeun; Anderson, William

    2016-01-01

    This article describes a weekly writing assignment named SelFeed (Self-Directed Learning with Feedback), in which students are asked to identify their own questions relevant to the lecture content and provide logical answers.

  15. Critical review of directional neutron survey meters

    Science.gov (United States)

    Balmer, Matthew J. I.; Gamage, Kelum A. A.; Taylor, Graeme C.

    2014-01-01

    Having been overlooked for many years, research is now starting to take into account the directional distribution of the neutron work place field. The impact of not taking this into account has led to overly conservative estimates of dose in neutron workplace fields. This paper provides a critical review of this existing research into directional survey meters which could improve these estimates of dose. Instruments which could be adapted for use as directional neutron survey meters are also considered within this review. Using Monte-Carlo techniques, two of the most promising existing designs are evaluated; a boron-doped liquid scintillator and a multi-detector directional spectrometer. As an outcome of these simulations, possible adaptations to these instruments are suggested with a view to improving the portability of the instrument.

  16. Critical Review of Directional Neutron Survey Meters

    International Nuclear Information System (INIS)

    Balmer, M.J.I.; Gamage, K.A.A.; Taylor, G.C.

    2013-06-01

    Having been overlooked for many years, research is now starting to take into account the directional distribution of the neutron work place field. The impact of not taking this into account has led to overly conservative estimates of dose in neutron workplace fields. This paper provides a critical review of this existing research into directional survey meters which could improve these estimates of dose. Instruments which could be adapted for use as directional neutron survey meters are also considered within this review. Using Monte-Carlo techniques, two of the most promising existing designs are evaluated; a boron-doped liquid scintillator and a multi-detector directional spectrometer. As an outcome of these simulations, possible adaptations to these instruments are suggested with a view to improving the portability of the instrument. (authors)

  17. Directional interstitial brachytherapy from simulation to application

    Science.gov (United States)

    Lin, Liyong

    Organs at risk (OAR) are sometimes adjacent to or embedded in or overlap with the clinical target volume (CTV) to be treated. The purpose of this PhD study is to develop directionally low energy gamma-emitting interstitial brachytherapy sources. These sources can be applied between OAR to selectively reduce hot spots in the OARs and normal tissues. The reduction of dose over undesired regions can expand patient eligibility or reduce toxicities for the treatment by conventional interstitial brachytherapy. This study covers the development of a directional source from design optimization to construction of the first prototype source. The Monte Carlo code MCNP was used to simulate the radiation transport for the designs of directional sources. We have made a special construction kit to assemble radioactive and gold-shield components precisely into D-shaped titanium containers of the first directional source. Directional sources have a similar dose distribution as conventional sources on the treated side but greatly reduced dose on the shielded side, with a sharp dose gradient between them. A three-dimensional dose deposition kernel for the 125I directional source has been calculated. Treatment plans can use both directional and conventional 125I sources at the same source strength for low-dose-rate (LDR) implants to optimize the dose distributions. For prostate tumors, directional 125I LDR brachytherapy can potentially reduce genitourinary and gastrointestinal toxicities and improve potency preservation for low risk patients. The combination of better dose distribution of directional implants and better therapeutic ratio between tumor response and late reactions enables a novel temporary LDR treatment, as opposed to permanent or high-dose-rate (HDR) brachytherapy for the intermediate risk T2b and high risk T2c tumors. Supplemental external-beam treatments can be shortened with a better brachytherapy boost for T3 tumors. In conclusion, we have successfully finished the

  18. The clinical microscope and direct composite veneer

    DEFF Research Database (Denmark)

    Pascotto, Renata C; Benetti, Ana Raquel

    2010-01-01

    This paper presents the advantages and limitations related to the use of a clinical microscope in restorative dentistry, and it demonstrates the aid of magnification during preparation and restoration of a direct composite veneer. Good illumination and visibility is important to adequately viewin...... the adjacent dental tissues so that the resin composite buildup can mimic natural teeth. The reproduction of details results in a naturally esthetic direct veneer....

  19. Ecodesign Directive version 2.0

    DEFF Research Database (Denmark)

    This present report reports on the main findings of the project Ecodesign Directive version 2.0 - from Energy Efficiency to Resource Efficiency. The project is financed by the Danish Environmental Protection Agency and ran from December 2012 to June 2014.......This present report reports on the main findings of the project Ecodesign Directive version 2.0 - from Energy Efficiency to Resource Efficiency. The project is financed by the Danish Environmental Protection Agency and ran from December 2012 to June 2014....

  20. A Direction Sensitive Fast Neutron Monitor

    Energy Technology Data Exchange (ETDEWEB)

    Antolkovic, B; Holmqvist, B; Wiedling, T

    1964-06-15

    A direction sensitive fast neutron monitor is described and its properties are discussed in some detail. The counter is a modification of the standard long counter of the Hanson and McKibben type. Directional sensitivity is obtained by increasing the shielding of the counter and providing it with a 70 cm long collimator channel. The behaviour of this long counter monitor is compared with that of a standard long counter when both are used in neutron experiments.

  1. Directions for computational mechanics in automotive crashworthiness

    Science.gov (United States)

    Bennett, James A.; Khalil, T. B.

    1993-01-01

    The automotive industry has used computational methods for crashworthiness since the early 1970's. These methods have ranged from simple lumped parameter models to full finite element models. The emergence of the full finite element models in the mid 1980's has significantly altered the research direction. However, there remains a need for both simple, rapid modeling methods and complex detailed methods. Some directions for continuing research are discussed.

  2. Some new directions in system transient simulation

    International Nuclear Information System (INIS)

    Ransom, V.H.

    1986-01-01

    The current research in system transient simulation at the Idaho National Engineering Laboratory (INEL) is summarized in this paper and three new directions that are emerging from this work are discussed. The new directions are: development of an Advanced Thermal Hydraulic Energy Network Analyzer (ATHENA) having new modeling capability, use of expert systems for enhancing simulation methods, and the trend to individual workstations for simulation

  3. Quantum Secure Direct Communication Based on Authentication

    International Nuclear Information System (INIS)

    Min-Jie, Wang; Wei, Pan

    2008-01-01

    We propose two schemes of quantum secure direct communication (QSDC) combined ideas of user authentication [Phys. Rev. A 73 (2006) 042305] and direct communication with dense coding [Phys. Rev. A. 68 (2003) 042317]. In these protocols, the privacy of authentication keys and the properties of the EPR pairs not only ensure the realization of identity authentication but also further improve the security of communication, and no secret messages are leaked even if the messages were broken. (general)

  4. Financial Frictions, Foreign Direct Investment, and Growth

    OpenAIRE

    Luis San Vicente Portes

    2010-01-01

    This paper assesses the role of financial frictions and Foreign Direct Investment (FDI) on an economy´s growth rate, business cycle volatility, and firm´s capital structure. We gauge these effects within the Financial Accelerator framework, where entrepreneurs can establish affiliates of local firms abroad through Foreign Direct Investment. Model simulations suggest that in the presence of credit market imperfections FDI is associated with faster growth, less leverage, and lower aggregate vol...

  5. Optimizing direct response in Internet display advertising

    OpenAIRE

    Aksakallı, Vural

    2013-01-01

    Internet display advertising has grown into a multi-billion dollar a year global industry and direct response campaigns account for about three-quarters of all Internet display advertising. In such campaigns, advertisers reach out to a target audience via some form of a visual advertisement (hereinafter also called “ad”) to maximize short-term sales revenue. In this study, we formulate an advertiser’s revenue maximization problem in direct response Internet display advertisement campaigns as ...

  6. Facebook marketing for a direct selling company

    OpenAIRE

    Egeberg, Chenette

    2015-01-01

    The purpose of the thesis was to provide recommendations for how the studied company could improve their Facebook marketing activities. The company was the Danish subsidiary of an multinational direct selling company of health and beauty products. The following research questions were devised: 1) What are the constraints and challenges for LR Denmark’s facebook marketing as a subsidiary of a Multinational Corporation and as a Direct Selling Company? 2) How can LR Denmark improve the...

  7. Finding Direction in the Search for Selection

    OpenAIRE

    Thiltgen, G.; Dos Reis, M.; Goldstein, R. A.

    2016-01-01

    Tests for positive selection have mostly been developed to look for diversifying selection where change away from the current amino acid is often favorable. However, in many cases we are interested in directional selection where there is a shift toward specific amino acids, resulting in increased fitness in the species. Recently, a few methods have been developed to detect and characterize directional selection on a molecular level. Using the results of evolutionary simulations as well as HIV...

  8. Nanoscale Science, Engineering and Technology Research Directions

    Energy Technology Data Exchange (ETDEWEB)

    Lowndes, D. H.; Alivisatos, A. P.; Alper, M.; Averback, R. S.; Jacob Barhen, J.; Eastman, J. A.; Imre, D.; Lowndes, D. H.; McNulty, I.; Michalske, T. A.; Ho, K-M; Nozik, A. J.; Russell, T. P.; Valentin, R. A.; Welch, D. O.; Barhen, J.; Agnew, S. R.; Bellon, P.; Blair, J.; Boatner, L. A.; Braiman, Y.; Budai, J. D.; Crabtree, G. W.; Feldman, L. C.; Flynn, C. P.; Geohegan, D. B.; George, E. P.; Greenbaum, E.; Grigoropoulos, C.; Haynes, T. E.; Heberlein, J.; Hichman, J.; Holland, O. W.; Honda, S.; Horton, J. A.; Hu, M. Z.-C.; Jesson, D. E.; Joy, D. C.; Krauss, A.; Kwok, W.-K.; Larson, B. C.; Larson, D. J.; Likharev, K.; Liu, C. T.; Majumdar, A.; Maziasz, P. J.; Meldrum, A.; Miller, J. C.; Modine, F. A.; Pennycook, S. J.; Pharr, G. M.; Phillpot, S.; Price, D. L.; Protopopescu, V.; Poker, D. B.; Pui, D.; Ramsey, J. M.; Rao, N.; Reichl, L.; Roberto, J.; Saboungi, M-L; Simpson, M.; Strieffer, S.; Thundat, T.; Wambsganss, M.; Wendleken, J.; White, C. W.; Wilemski, G.; Withrow, S. P.; Wolf, D.; Zhu, J. H.; Zuhr, R. A.; Zunger, A.; Lowe, S.

    1999-01-01

    This report describes important future research directions in nanoscale science, engineering and technology. It was prepared in connection with an anticipated national research initiative on nanotechnology for the twenty-first century. The research directions described are not expected to be inclusive but illustrate the wide range of research opportunities and challenges that could be undertaken through the national laboratories and their major national scientific user facilities with the support of universities and industry.

  9. Sports Tournament Predictions Using Direct Manipulation

    OpenAIRE

    Vuillemot , Romain; Perin , Charles

    2016-01-01

    An advanced interface for sports tournament predictions uses direct manipulation to allow users to make nonlinear predictions. Unlike previous interface designs, the interface helps users focus on their prediction tasks by enabling them to first choose a winner and then fill out the rest of the bracket. In real-world tests of the proposed interface (for the 2014 FIFA World Cup tournament and 2015/2016 UEFA Champions League), the authors validated the use of direct manipulation as an alternati...

  10. Agricultural insurance under the Solvency II Directive

    Directory of Open Access Journals (Sweden)

    Njegomir Vladimir

    2014-01-01

    Full Text Available Solvency II Directive represents a new framework of unique solvency regulation of insurance and reinsurance companies in the European Union. Although it has not yet been implemented in national legislations, it can be concluded, based on the directive wording and conducted quantitative studies, that it will have implications on agricultural producers since they are the users of insurance services. The aim of the research presented in this paper is to analyse the implications of the new directive to agricultural producers since they are the insureds and the main actors of agribusiness. Firstly, the paper gives an overview of the basic features of the new regulatory framework and then it points at the issues and the needs for intensive application of Directive in order to improve the insurance business in Serbia. The process will direct the settlement of major claims, the ones that are typical of catastrophic risks in agriculture, towards the insurance, while the expectations from the government will be directed towards the regulation of the setting and economic measures (development and investment subsidies, cooperative movement. In addition, the paper points at the demands of the new regulation and analyses the implications of the new regulation regarding the settlement of claims resulting from major flood since it represents the example that proves the basic postulate.

  11. Directional sound radiation from substation transformers

    International Nuclear Information System (INIS)

    Maybee, N.

    2009-01-01

    This paper presented the results of a study in which acoustical measurements at two substations were analyzed to investigate the directional behaviour of typical arrays having 2 or 3 transformers. Substation transformers produce a characteristic humming sound that is caused primarily by vibration of the core at twice the frequency of the power supply. The humming noise radiates predominantly from the tank enclosing the core. The main components of the sound are harmonics of 120 Hz. Sound pressure level data were obtained for various directions and distances from the arrays, ranging from 0.5 m to over 100 m. The measured sound pressure levels of the transformer tones displayed substantial positive and negative excursions from the calculated average values for many distances and directions. The results support the concept that the directional effects are associated with constructive and destructive interference of tonal sound waves emanating from different parts of the array. Significant variations in the directional sound pattern can occur in the near field of a single transformer or an array, and the extent of the near field is significantly larger than the scale of the array. Based on typical dimensions for substation sites, the distance to the far field may be much beyond the substation boundary and beyond typical setbacks to the closest dwellings. As such, the directional sound radiation produced by transformer arrays introduces additional uncertainty in the prediction of substation sound levels at dwellings within a few hundred meters of a substation site. 4 refs., 4 figs.

  12. Bio-Inspired Micromechanical Directional Acoustic Sensor

    Science.gov (United States)

    Swan, William; Alves, Fabio; Karunasiri, Gamani

    Conventional directional sound sensors employ an array of spatially separated microphones and the direction is determined using arrival times and amplitudes. In nature, insects such as the Ormia ochracea fly can determine the direction of sound using a hearing organ much smaller than the wavelength of sound it detects. The fly's eardrums are mechanically coupled, only separated by about 1 mm, and have remarkable directional sensitivity. A micromechanical sensor based on the fly's hearing system was designed and fabricated on a silicon on insulator (SOI) substrate using MEMS technology. The sensor consists of two 1 mm2 wings connected using a bridge and to the substrate using two torsional legs. The dimensions of the sensor and material stiffness determine the frequency response of the sensor. The vibration of the wings in response to incident sound at the bending resonance was measured using a laser vibrometer and found to be about 1 μm/Pa. The electronic response of the sensor to sound was measured using integrated comb finger capacitors and found to be about 25 V/Pa. The fabricated sensors showed good directional sensitivity. In this talk, the design, fabrication and characteristics of the directional sound sensor will be described. Supported by ONR and TDSI.

  13. Empirical validation of directed functional connectivity.

    Science.gov (United States)

    Mill, Ravi D; Bagic, Anto; Bostan, Andreea; Schneider, Walter; Cole, Michael W

    2017-02-01

    Mapping directions of influence in the human brain connectome represents the next phase in understanding its functional architecture. However, a host of methodological uncertainties have impeded the application of directed connectivity methods, which have primarily been validated via "ground truth" connectivity patterns embedded in simulated functional MRI (fMRI) and magneto-/electro-encephalography (MEG/EEG) datasets. Such simulations rely on many generative assumptions, and we hence utilized a different strategy involving empirical data in which a ground truth directed connectivity pattern could be anticipated with confidence. Specifically, we exploited the established "sensory reactivation" effect in episodic memory, in which retrieval of sensory information reactivates regions involved in perceiving that sensory modality. Subjects performed a paired associate task in separate fMRI and MEG sessions, in which a ground truth reversal in directed connectivity between auditory and visual sensory regions was instantiated across task conditions. This directed connectivity reversal was successfully recovered across different algorithms, including Granger causality and Bayes network (IMAGES) approaches, and across fMRI ("raw" and deconvolved) and source-modeled MEG. These results extend simulation studies of directed connectivity, and offer practical guidelines for the use of such methods in clarifying causal mechanisms of neural processing. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Frontal transcranial direct current stimulation (tDCS) abolishes list-method directed forgetting.

    Science.gov (United States)

    Silas, Jonathan; Brandt, Karen R

    2016-03-11

    It is a point of controversy as to whether directed forgetting effects are a result of active inhibition or a change of context initiated by the instruction to forget. In this study we test the causal role of active inhibition in directed forgetting. By applying cathodal transcranial direct current stimulation (tDCS) over the right prefrontal cortex we suppressed cortical activity commonly associated with inhibitory control. Participants who underwent real brain stimulation before completing the directed forgetting paradigm showed no directed forgetting effects. Conversely, those who underwent sham brain stimulation demonstrated classical directed forgetting effects. We argue that these findings suggest that inhibition is the primary mechanism that results in directed forgetting costs and benefits. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Direct photons in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Baeuchle, Bjoern

    2010-12-13

    Direct photon emission from heavy-ion collisions has been calculated and compared to available experimental data. Three different models have been combined to extract direct photons from different environments in a heavy-ion collision: Thermal photons from partonic and hadronic matter have been extracted from relativistic, non-viscous 3+1-dimensional hydrodynamic calculations. Thermal and non-thermal photons from hadronic interactions have been calculated from relativistic transport theory. The impact of different physics assumptions about the thermalized matter has been studied. The models used for the determination of photons from both hydrodynamic and transport calculations have been elucidated and their numerical properties tested. The origin of direct photons, itemised by emission stage, emission time, channel and baryon number density, has been investigated for various systems, as have the transverse momentum spectra and elliptic flow patterns of direct photons. Taking into account the full (vacuum) spectral function of the rho-meson decreases the direct photon emission by approximately 10% at low photon transverse momentum. In all systems that have been considered -- heavy-ion collisions at E{sub lab}=35 AGeV and 158 AGeV, (s{sub NN}){sup 1/2}=62.4 GeV, 130 GeV and 200 GeV -- thermal emission from a system with partonic degrees of freedom is greatly enhanced over that from hadronic systems, while the difference between the direct photon yields from a viscous and a non-viscous hadronic system (transport vs. hydrodynamics) is found to be very small. Predictions for direct photon emission in central U+U-collisions at 35 AGeV have been made. (orig.)

  16. Direct photons in heavy-ion collisions

    International Nuclear Information System (INIS)

    Baeuchle, Bjoern

    2010-01-01

    Direct photon emission from heavy-ion collisions has been calculated and compared to available experimental data. Three different models have been combined to extract direct photons from different environments in a heavy-ion collision: Thermal photons from partonic and hadronic matter have been extracted from relativistic, non-viscous 3+1-dimensional hydrodynamic calculations. Thermal and non-thermal photons from hadronic interactions have been calculated from relativistic transport theory. The impact of different physics assumptions about the thermalized matter has been studied. The models used for the determination of photons from both hydrodynamic and transport calculations have been elucidated and their numerical properties tested. The origin of direct photons, itemised by emission stage, emission time, channel and baryon number density, has been investigated for various systems, as have the transverse momentum spectra and elliptic flow patterns of direct photons. Taking into account the full (vacuum) spectral function of the rho-meson decreases the direct photon emission by approximately 10% at low photon transverse momentum. In all systems that have been considered -- heavy-ion collisions at E lab =35 AGeV and 158 AGeV, (s NN ) 1/2 =62.4 GeV, 130 GeV and 200 GeV -- thermal emission from a system with partonic degrees of freedom is greatly enhanced over that from hadronic systems, while the difference between the direct photon yields from a viscous and a non-viscous hadronic system (transport vs. hydrodynamics) is found to be very small. Predictions for direct photon emission in central U+U-collisions at 35 AGeV have been made. (orig.)

  17. Determination of radiation direction in environmental monitoring

    International Nuclear Information System (INIS)

    Campos, Vicente de Paulo de; Moura, Eduardo S.; Rocha, Felicia D.G.; Manzoli, Jose Eduardo

    2009-01-01

    The assessment of environmental exposure has been performed in Brazil using the thermoluminescence technique at Thermoluminescence Dosimetry Laboratory (LDT), at Nuclear and Energetic Research Institute (IPEN/CNEN-SP). To carry out these measurements, several thermoluminescent dosimeters (TLD's) were used to measure the expose. In this procedure, very few information of direction where the radiation came from is available. A vague supposition about the direction from where the radiation came from could be inferred only by evaluation of multiple dosimeters displaced at entire region of monitoring, but this demand to much effort or sometimes become impractical for certain situations. In this work, a single device is used to provide information about the direction from where the radiation came through. This device is called directional dosimeter (DD). Using more than one DD it is possible to reduce the uncertainty of the measurements and determine the radiation source position. The DD basically consists of a regular solid with high effective atomic number, where one TLD is positioned at each face. The DD allows evaluating the environmental exposure and the direction of the radiation by a simple vector sum. At each face of the DD, it is associated an orthogonal vector, and modulus of this vector represents the correspond exposure measured by the TLD. The direction of the radiation source is the sum of these faces vectors. The prototype used in this work was a lead cube with six TLDs of CaSO 4 :Dy/Teflon. The TLDs have high sensibility and are already used in area, environmental and personal monitoring. The measurements had shown the correct environmental exposure and a good indication of the radiation direction. (author)

  18. Measurement of the velocity of sound in crystals by pulsed neutron diffraction

    International Nuclear Information System (INIS)

    Willis, B.T.M.; Carlile, C.J.; Ward, R.C.; David, W.I.F.; Johnson, M.W.

    1986-03-01

    The diffraction method of observing elementary excitations in crystals has been applied to the study of one-phonon thermal diffuse scattering from pyrolytic graphite on a high resolution pulsed neutron diffractometer. The variation of the phase velocity of sound as a function of direction in the crystal and efficient method of determining sound velocities in crystals under extreme conditions. (author)

  19. Directional connectivity in hydrology and ecology

    Science.gov (United States)

    Larsen, Laurel G.; Choi, Jungyill; Nungesser, Martha K.; Harvey, Judson W.

    2012-01-01

    Quantifying hydrologic and ecological connectivity has contributed to understanding transport and dispersal processes and assessing ecosystem degradation or restoration potential. However, there has been little synthesis across disciplines. The growing field of ecohydrology and recent recognition that loss of hydrologic connectivity is leading to a global decline in biodiversity underscore the need for a unified connectivity concept. One outstanding need is a way to quantify directional connectivity that is consistent, robust to variations in sampling, and transferable across scales or environmental settings. Understanding connectivity in a particular direction (e.g., streamwise, along or across gradient, between sources and sinks, along cardinal directions) provides critical information for predicting contaminant transport, planning conservation corridor design, and understanding how landscapes or hydroscapes respond to directional forces like wind or water flow. Here we synthesize progress on quantifying connectivity and develop a new strategy for evaluating directional connectivity that benefits from use of graph theory in ecology and percolation theory in hydrology. The directional connectivity index (DCI) is a graph-theory based, multiscale metric that is generalizable to a range of different structural and functional connectivity applications. It exhibits minimal sensitivity to image rotation or resolution within a given range and responds intuitively to progressive, unidirectional change. Further, it is linearly related to the integral connectivity scale length—a metric common in hydrology that correlates well with actual fluxes—but is less computationally challenging and more readily comparable across different landscapes. Connectivity-orientation curves (i.e., directional connectivity computed over a range of headings) provide a quantitative, information-dense representation of environmental structure that can be used for comparison or detection of

  20. Directional connectivity in hydrology and ecology.

    Science.gov (United States)

    Larsen, Laurel G; Choi, Jungyill; Nungesser, Martha K; Harvey, Judson W

    2012-12-01

    Quantifying hydrologic and ecological connectivity has contributed to understanding transport and dispersal processes and assessing ecosystem degradation or restoration potential. However, there has been little synthesis across disciplines. The growing field of ecohydrology and recent recognition that loss of hydrologic connectivity is leading to a global decline in biodiversity underscore the need for a unified connectivity concept. One outstanding need is a way to quantify directional connectivity that is consistent, robust to variations in sampling, and transferable across scales or environmental settings. Understanding connectivity in a particular direction (e.g., streamwise, along or across gradient, between sources and sinks, along cardinal directions) provides critical information for predicting contaminant transport, planning conservation corridor design, and understanding how landscapes or hydroscapes respond to directional forces like wind or water flow. Here we synthesize progress on quantifying connectivity and develop a new strategy for evaluating directional connectivity that benefits from use of graph theory in ecology and percolation theory in hydrology. The directional connectivity index (DCI) is a graph-theory based, multiscale metric that is generalizable to a range of different structural and functional connectivity applications. It exhibits minimal sensitivity to image rotation or resolution within a given range and responds intuitively to progressive, unidirectional change. Further, it is linearly related to the integral connectivity scale length--a metric common in hydrology that correlates well with actual fluxes--but is less computationally challenging and more readily comparable across different landscapes. Connectivity-orientation curves (i.e., directional connectivity computed over a range of headings) provide a quantitative, information-dense representation of environmental structure that can be used for comparison or detection of