WorldWideScience

Sample records for nonlinear grey thermal

  1. Grey relationship analysis and grey forecasting modeling on thermal stability of synthetic single diamond

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Through analyzing 7 Ib-type samples of synthetic single diamonds by their DTA and TG in air, we ascertained the extrapolated onset temperature on the curves of DTA as the characteristic temperature of their thermal stabilities. Based on the grey system theory, we analyzed 4 factors influential in the thermal stability by the grey relationship analysis, a quantitative method, and derived the grey relationship sequence, that is, the rank of the influence extent of 4 factors on the thermal stability. Furthermore, we established the grey forecasting model, namely GM ( 1,5 ), for predicting the thermal stability of single diamonds with their intrinsic properties, which was then examined by a deviation-probability examination. The results illustrate that it is reasonable to take the Extrapolated Onset Temperature in DTA as the characteristic temperature for thermal stability (TS)of Ib -type synthetic single diamonds. The nitrogen content and grain shape regularity of diamonds are dominating factors. Likewise, grain size and compressive strength are minor factors. In addition, GM (1,5) can be used to predict the thermal stability of Ib-type synthetic single diamonds available. The precision rank of GM( 1,5 ) is‘GOOD’.

  2. Effects of carbon content and solidification rate on thermal conductivity of grey cast iron

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The thermal conductivity or diffusivity of pearlitic grey irons with various carbon contents is investigated by the laser flash method. The materials are cast in controlled thermal environments and produced in three dissimilar cooling rates. The cooling rate together with the carbon content largely influence the thermal conductivity of grey iron. Linear relationships exist between the thermal conductivity and the carbon content, the carbon equivalent and the fraction of former primary solidified austenite transformed into pearlite. The work shows that optimal thermal transport properties are obtained at medium cooling rates. Equations describing the thermal conductivity of pearlite,solidified as pre-eutectic austenite, and the eutectic of grey iron are derived. The thermal conductivity of pearlitic grey iron is modeled at both room temperature and elevated temperature with good accuracy.

  3. Effects of Carbon Content and Solidification Rate on the Thermal Conductivity of Grey Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Daniel Holmgren; Attila Diószegi; Ingvar L.Svensson

    2008-01-01

    The thermal conductivity/diffusivity of pearlitic grey irons with various carbon contents was investi- gated by the laser flash method. The materials were cast in controlled thermal environments producing three dissimilar cooling rates. The cooling rates together with the carbon content largely influence the thermal conductivity of grey iron. Linear relationships exist between the thermal conductivity and the carbon content, the carbon equivalent, and the fraction of the former primary solidified austenite transformed into pearlite. The results show that the optimal thermal transport properties are obtained at medium cooling rates. Equa- tions are given for the thermal conductivity of pearlite, solidified as pre-eutectic austenite, and the eutectic of grey iron. The thermal conductivity of pearlitic grey iron is modelled at both room temperature and elevated temperatures with good accuracy.

  4. Effects of carbon content and solidification rate on thermal conductivity of grey cast iron

    Directory of Open Access Journals (Sweden)

    Daniel Holmgren

    2007-08-01

    Full Text Available The thermal conductivity or diffusivity of pearlitic grey irons with various carbon contents is investigated by the laser flash method. The materials are cast in controlled thermal environments and produced in three dissimilar cooling rates. The cooling rate together with the carbon content largely influence the thermal conductivity of grey iron. Linear relationships exist between the thermal conductivity and the carbon content, the carbon equivalent and the fraction of former primary solidified austenite transformed into pearlite. The work shows that optimal thermal transport properties are obtained at medium cooling rates. Equations describing the thermal conductivity of pearlite,solidified as pre-eutectic austenite, and the eutectic of grey iron are derived. The thermal conductivity of pearlitic grey iron is modeled at both room temperature and elevated temperature with good accuracy.

  5. High-order solution methods for grey discrete ordinates thermal radiative transfer

    Science.gov (United States)

    Maginot, Peter G.; Ragusa, Jean C.; Morel, Jim E.

    2016-12-01

    This work presents a solution methodology for solving the grey radiative transfer equations that is both spatially and temporally more accurate than the canonical radiative transfer solution technique of linear discontinuous finite element discretization in space with implicit Euler integration in time. We solve the grey radiative transfer equations by fully converging the nonlinear temperature dependence of the material specific heat, material opacities, and Planck function. The grey radiative transfer equations are discretized in space using arbitrary-order self-lumping discontinuous finite elements and integrated in time with arbitrary-order diagonally implicit Runge-Kutta time integration techniques. Iterative convergence of the radiation equation is accelerated using a modified interior penalty diffusion operator to precondition the full discrete ordinates transport operator.

  6. High-order solution methods for grey discrete ordinates thermal radiative transfer

    Energy Technology Data Exchange (ETDEWEB)

    Maginot, Peter G., E-mail: maginot1@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Ragusa, Jean C., E-mail: jean.ragusa@tamu.edu [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States); Morel, Jim E., E-mail: morel@tamu.edu [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States)

    2016-12-15

    This work presents a solution methodology for solving the grey radiative transfer equations that is both spatially and temporally more accurate than the canonical radiative transfer solution technique of linear discontinuous finite element discretization in space with implicit Euler integration in time. We solve the grey radiative transfer equations by fully converging the nonlinear temperature dependence of the material specific heat, material opacities, and Planck function. The grey radiative transfer equations are discretized in space using arbitrary-order self-lumping discontinuous finite elements and integrated in time with arbitrary-order diagonally implicit Runge–Kutta time integration techniques. Iterative convergence of the radiation equation is accelerated using a modified interior penalty diffusion operator to precondition the full discrete ordinates transport operator.

  7. Yellowing and bleaching of grey hair caused by photo and thermal degradation.

    Science.gov (United States)

    Richena, M; Silveira, M; Rezende, C A; Joekes, I

    2014-09-05

    Yellowing is an undesirable phenomenon that is common in people with white and grey hair. Because white hair has no melanin, the pigment responsible for hair colour, the effects of photodegradation are more visible in this type of hair. The origin of yellowing and its relation to photodegradation processes are not properly established, and many questions remain open in this field. In this work, the photodegradation of grey hair was investigated as a function of the wavelength of incident radiation, and its ultrastructure was determined, always comparing the results obtained for the white and black fibres present in grey hair with the results of white wool. The results presented herein indicate that the photobehaviour of grey hair irradiated with a mercury lamp or with solar radiation is dependent on the wavelength range of the incident radiation and on the initial shade of yellow in the sample. Two types of grey hair were used: (1) blended grey hair (more yellow) and (2) grey hair from a single-donor (less yellow). After exposure to a full-spectrum mercury lamp for 200 h, the blended white hair turned less yellow (the yellow-blue difference, Db(*) becomes negative, Db(*)=-6), whereas the white hair from the single-donor turned slightly yellower (Db(*)=2). In contrast, VIS+IR irradiation resulted in bleaching in both types of hair, whereas a thermal treatment (at 81 °C) caused yellowing of both types of hair, resulting in a Db(*)=3 for blended white hair and Db(*)=9 for single-donor hair. The identity of the yellow chromophores was investigated by UV-Vis spectroscopy. The results obtained with this technique were contradictory, however, and it was not possible to obtain a simple correlation between the sample shade of yellow and the absorption spectra. In addition, the results are discussed in terms of the morphology differences between the pigmented and non-pigmented parts of grey hair, the yellowing and bleaching effects of grey hair, and the occurrence of dark

  8. Nonlinear Thermal Compensators for WGM Resonators

    Science.gov (United States)

    Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry; Maleki, Lute; Yu, Nan; Iltchenko, Vladimir

    2009-01-01

    In an alternative version of a proposed bimaterial thermal compensator for a whispering-gallery-mode (WGM) optical resonator, a mechanical element having nonlinear stiffness would be added to enable stabilization of a desired resonance frequency at a suitable fixed working temperature. The previous version was described in "Bimaterial Thermal Compensators for WGM Resonators." Both versions are intended to serve as inexpensive means of preventing (to first order) or reducing temperature-related changes in resonance frequencies.

  9. Thermal Error Modeling of a Machining Center Using Grey System Theory and Adaptive Network-Based Fuzzy Inference System

    Science.gov (United States)

    Wang, Kun-Chieh; Tseng, Pai-Chung; Lin, Kuo-Ming

    Thermal effect on machine tools is a well-recognized problem in an environment of increasing demand for product quality. The performance of a thermal error compensation system typically depends on the accuracy and robustness of the thermal error model. This work presents a novel thermal error model utilizing two mathematic schemes: the grey system theory and the adaptive network-based fuzzy inference system (ANFIS). First, the measured temperature and deformation results are analyzed via the grey system theory to obtain the influence ranking of temperature ascent on thermal drift of spindle. Then, using the highly ranked temperature ascents as inputs for the ANFIS and training these data by the hybrid learning rule, a thermal compensation model is constructed. The grey system theory effectively reduces the number of temperature sensors needed on a machine structure for prediction, and the ANFIS has the advantages of good accuracy and robustness. For testing the performance of proposed ANFIS model, a real-cutting operation test was conducted. Comparison results demonstrate that the modeling schemes of the ANFIS coupled with the grey system theory has good predictive ability.

  10. Thermal rectification in nonlinear quantum circuits

    DEFF Research Database (Denmark)

    Ruokola, T.; Ojanen, T.; Jauho, Antti-Pekka

    2009-01-01

    We present a theoretical study of radiative heat transport in nonlinear solid-state quantum circuits. We give a detailed account of heat rectification effects, i.e., the asymmetry of heat current with respect to a reversal of the thermal gradient, in a system consisting of two reservoirs at finite...

  11. Forecasting of foreign exchange rates of Taiwan’s major trading partners by novel nonlinear Grey Bernoulli model NGBM(1, 1)

    Science.gov (United States)

    Chen, Chun-I.; Chen, Hong Long; Chen, Shuo-Pei

    2008-08-01

    The traditional Grey Model is easy to understand and simple to calculate, with satisfactory accuracy, but it is also lack of flexibility to adjust the model to acquire higher forecasting precision. This research studies feasibility and effectiveness of a novel Grey model together with the concept of the Bernoulli differential equation in ordinary differential equation. In this research, the author names this newly proposed model as Nonlinear Grey Bernoulli Model (NGBM). The NGBM is nonlinear differential equation with power index n. By controlling n, the curvature of the solution curve could be adjusted to fit the result of one time accumulated generating operation (1-AGO) of raw data. One extreme case from Grey system textbook is studied by NGBM, and two published articles are chosen for practical tests of NGBM. The results prove the novel NGBM is feasible and efficient. Finally, NGBM is used to forecast 2005 foreign exchange rates of twelve Taiwan major trading partners, including Taiwan.

  12. Nonlinear wave propagation in constrained solids subjected to thermal loads

    Science.gov (United States)

    Nucera, Claudio; Lanza di Scalea, Francesco

    2014-01-01

    The classical mathematical treatment governing nonlinear wave propagation in solids relies on finite strain theory. In this scenario, a system of nonlinear partial differential equations can be derived to mathematically describe nonlinear phenomena such as acoustoelasticity (wave speed dependency on quasi-static stress), wave interaction, wave distortion, and higher-harmonic generation. The present work expands the topic of nonlinear wave propagation to the case of a constrained solid subjected to thermal loads. The origin of nonlinear effects in this case is explained on the basis of the anharmonicity of interatomic potentials, and the absorption of the potential energy corresponding to the (prevented) thermal expansion. Such "residual" energy is, at least, cubic as a function of strain, hence leading to a nonlinear wave equation and higher-harmonic generation. Closed-form solutions are given for the longitudinal wave speed and the second-harmonic nonlinear parameter as a function of interatomic potential parameters and temperature increase. The model predicts a decrease in longitudinal wave speed and a corresponding increase in nonlinear parameter with increasing temperature, as a result of the thermal stresses caused by the prevented thermal expansion of the solid. Experimental measurements of the ultrasonic nonlinear parameter on a steel block under constrained thermal expansion confirm this trend. These results suggest the potential of a nonlinear ultrasonic measurement to quantify thermal stresses from prevented thermal expansion. This knowledge can be extremely useful to prevent thermal buckling of various structures, such as continuous-welded rails in hot weather.

  13. Grey Box Non-Linearities Modeling and Characterization of a BandPass BAW Filter

    Directory of Open Access Journals (Sweden)

    M. Mabrouk

    2016-06-01

    Full Text Available In this work, the non-linearities of a 3G/UMTS geared BandPass Bulk Acoustic Wave ladder filter composed of five resonators were modeled using non-linear modified Butterworth-Van Dyke model. The non-linear characteristics were measured and simulated, and they were compared and found to be fairly identical. The filter's central frequency is 2.12 GHz, the corresponding bandwidth is 61.55 MHz, and the quality factor is 34.55.

  14. Grey analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cable, G.D.

    1996-12-01

    Grey logic is not another name for fuzzy logic. Grey logic--also called grey analysis or grey system theory--is a new technology, a group of techniques for system analysis and modeling. Like fuzzy logic, grey logic is useful in situations with incomplete and uncertain information. Grey analysis is particularly applicable in instances with very limited data and in cases with little system knowledge or understanding. In this paper, a summary of the basic concepts of grey analysis is provided, with descriptions of its application to several classes of problems. Calculations methods are provided for grey relation analysis, and for modeling and prediction using grey methods.

  15. Thermally induced nonlinear mode coupling in high power fiber amplifiers

    DEFF Research Database (Denmark)

    Johansen, Mette Marie; Hansen, Kristian Rymann; Alkeskjold, Thomas T.;

    2013-01-01

    Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W.......Thermally induced nonlinear mode coupling leads to transverse mode instability (TMI) in high power fiber amplifiers. A numerical model including altering mode profiles from thermal effects and waveguide perturbations predicts a TMI threshold of ~200W....

  16. Brain thermal inertia, but no evidence for selective brain cooling, in free-ranging western grey kangaroos (Macropus fuliginosus).

    Science.gov (United States)

    Maloney, Shane K; Fuller, Andrea; Meyer, Leith C R; Kamerman, Peter R; Mitchell, Graham; Mitchell, Duncan

    2009-04-01

    Marsupials reportedly can implement selective brain cooling despite lacking a carotid rete. We measured brain (hypothalamic) and carotid arterial blood temperatures every 5 min for 5, 17, and 63 days in spring in three free-living western grey kangaroos. Body temperature was highest during the night, and decreased rapidly early in the morning, reaching a nadir at 10:00. The highest body temperatures recorded occurred sporadically in the afternoon, presumably associated with exercise. Hypothalamic temperature consistently exceeded arterial blood temperature, by an average 0.3 degrees C, except during these afternoon events when hypothalamic temperature lagged behind, and was occasionally lower than, the simultaneous arterial blood temperature. The reversal in temperatures resulted from the thermal inertia of the brain; changes in the brain to arterial blood temperature difference were related to the rate of change of arterial blood temperature on both heating and cooling (P cooling in kangaroos. The effect of thermal inertia on brain temperature is larger than might be expected in the grey kangaroo, a discrepancy that we speculate derives from the unique vascular anatomy of the marsupial brain.

  17. Nonlinear/linear unified thermal stress formulations - Transfinite element approach

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    A new unified computational approach for applicability to nonlinear/linear thermal-structural problems is presented. Basic concepts of the approach including applicability to nonlinear and linear thermal structural mechanics are first described via general formulations. Therein, the approach is demonstrated for thermal stress and thermal-structural dynamic applications. The proposed transfinite element approach focuses on providing a viable hybrid computational methodology by combining the modeling versatility of contemporary finite element schemes in conjunction with transform techniques and the classical Bubnov-Galerkin schemes. Comparative samples of numerical test cases highlight the capabilities of the proposed concepts.

  18. Improved Z-scan adjustment to thermal nonlinearities by including nonlinear absorption

    Science.gov (United States)

    Severiano-Carrillo, I.; Alvarado-Méndez, E.; Trejo-Durán, M.; Méndez-Otero, M. M.

    2017-08-01

    We propose a modified mathematical model of thermal optical nonlinearities which allow us to obtain the nonlinear refraction index and the nonlinear absorption coefficient with only one measurement. This modification is motivated by the influence that nonlinear absorption has on the measurement of the nonlinear refraction index at far field, when the material presents a large nonlinearity. This model, where nonlinear absorption is considered to adjust the curves of nonlinear refraction index obtained by Z-scan technique, has the best agreement with experimental data. The model is validated with two ionic liquids and the organic material Eysenhardtia polystachya, in thin media. We present these results after comparing our proposed model to other reported models.

  19. Linear iterative technique for solution of nonlinear thermal network problems

    Energy Technology Data Exchange (ETDEWEB)

    Seabourn, C.M.

    1976-11-01

    A method for rapid and accurate solution of linear and/or nonlinear thermal network problems is described. It is a matrix iterative process that converges for nodal temperatures and variations of thermal conductivity with temperature. The method is computer oriented and can be changed easily for design studies.

  20. IEA Common Exercise 4: ARX, ARMAX and grey-box models for thermal performance characterization of the test box

    DEFF Research Database (Denmark)

    Bacher, Peder; Andersen, Philip Hvidthøft Delff

    In this report results of applying time series models for assessing the thermal performance of the IEA Annex 58 test box based on data given in the Common Exercise 4 (CE4), which was measured in Almeria, Spain. Both ARX, ARMAX and grey-box models are applied. Finally, the same models are fitted...... for the Common Exercise 3b (CE3) data measured in Belgium and the results are compared. The focus in this report is on model selection and validation enabling a stable and reliable performance assessment. Basically, the challenge is to find a procedure for each type of model, which can give un...... radiation is present data), these aspects are discussed. Furthermore, new models for enhancing the description of the effect of solar radiation on the test box is presented....

  1. Thermal rectification and negative differential thermal conductance in harmonic chains with nonlinear system-bath coupling.

    Science.gov (United States)

    Ming, Yi; Li, Hui-Min; Ding, Ze-Jun

    2016-03-01

    Thermal rectification and negative differential thermal conductance were realized in harmonic chains in this work. We used the generalized Caldeira-Leggett model to study the heat flow. In contrast to most previous studies considering only the linear system-bath coupling, we considered the nonlinear system-bath coupling based on recent experiment [Eichler et al., Nat. Nanotech. 6, 339 (2011)]. When the linear coupling constant is weak, the multiphonon processes induced by the nonlinear coupling allow more phonons transport across the system-bath interface and hence the heat current is enhanced. Consequently, thermal rectification and negative differential thermal conductance are achieved when the nonlinear couplings are asymmetric. However, when the linear coupling constant is strong, the umklapp processes dominate the multiphonon processes. Nonlinear coupling suppresses the heat current. Thermal rectification is also achieved. But the direction of rectification is reversed compared to the results of weak linear coupling constant.

  2. Thermal rectification and negative differential thermal conductance in harmonic chains with nonlinear system-bath coupling

    Science.gov (United States)

    Ming, Yi; Li, Hui-Min; Ding, Ze-Jun

    2016-03-01

    Thermal rectification and negative differential thermal conductance were realized in harmonic chains in this work. We used the generalized Caldeira-Leggett model to study the heat flow. In contrast to most previous studies considering only the linear system-bath coupling, we considered the nonlinear system-bath coupling based on recent experiment [Eichler et al., Nat. Nanotech. 6, 339 (2011), 10.1038/nnano.2011.71]. When the linear coupling constant is weak, the multiphonon processes induced by the nonlinear coupling allow more phonons transport across the system-bath interface and hence the heat current is enhanced. Consequently, thermal rectification and negative differential thermal conductance are achieved when the nonlinear couplings are asymmetric. However, when the linear coupling constant is strong, the umklapp processes dominate the multiphonon processes. Nonlinear coupling suppresses the heat current. Thermal rectification is also achieved. But the direction of rectification is reversed compared to the results of weak linear coupling constant.

  3. A Study of Thermal Contact using Nonlinear System Identification Models

    Directory of Open Access Journals (Sweden)

    M. H. Shojaeefard

    2008-01-01

    Full Text Available One interesting application of system identification method is to identify and control the heat transfer from the exhaust valve to the seat to keep away the valve from being damaged. In this study, two co-axial cylindrical specimens are used as exhaust valve and its seat. Using the measured temperatures at different locations of the specimens and with a semi-analytical method, the temperature distribution of the specimens is calculated and consequently, the thermal contact conductance is calculated. By applying the system identification method and having the temperatures at both sides of the contact surface, the temperature transfer function is calculated. With regard to the fact that the thermal contact has nonlinear behavior, two nonlinear black-box models called nonlinear ARX and NLN Hammerstein-Wiener models are taken for accurate estimation. Results show that the NLN Hammerstein-Wiener models with wavelet network nonlinear estimator is the best.

  4. A hybrid transfinite element approach for nonlinear transient thermal analysis

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    A new computational approach for transient nonlinear thermal analysis of structures is proposed. It is a hybrid approach which combines the modeling versatility of contemporary finite elements in conjunction with transform methods and classical Bubnov-Galerkin schemes. The present study is limited to nonlinearities due to temperature-dependent thermophysical properties. Numerical test cases attest to the basic capabilities and therein validate the transfinite element approach by means of comparisons with conventional finite element schemes and/or available solutions.

  5. Imaging thermal fields in nonlinear photoacoustics

    NARCIS (Netherlands)

    Oshurko, V. B.

    2006-01-01

    It is demonstrated that the shape of a photoacoustic response in systems with a temperature-dependent thermal expansion coefficient (thermononlinear case) represents a wavelet transform of the spatial distribution of heat sources.

  6. Extra phase noise from thermal fluctuations in nonlinear optical crystals

    DEFF Research Database (Denmark)

    César, J. E. S.; Coelho, A.S.; Cassemiro, K.N.

    2009-01-01

    We show theoretically and experimentally that scattered light by thermal phonons inside a second-order nonlinear crystal is the source of additional phase noise observed in optical parametric oscillators. This additional phase noise reduces the quantum correlations and has hitherto hindered the d...... the direct production of multipartite entanglement in a single nonlinear optical system. We cooled the nonlinear crystal and observed a reduction in the extra noise. Our treatment of this noise can be successfully applied to different systems in the literature....

  7. Dynamic nonlinear thermal optical effects in coupled ring resonators

    Directory of Open Access Journals (Sweden)

    Chenguang Huang

    2012-09-01

    Full Text Available We investigate the dynamic nonlinear thermal optical effects in a photonic system of two coupled ring resonators. A bus waveguide is used to couple light in and out of one of the coupled resonators. Based on the coupling from the bus to the resonator, the coupling between the resonators and the intrinsic loss of each individual resonator, the system transmission spectrum can be classified by three different categories: coupled-resonator-induced absorption, coupled-resonator-induced transparency and over coupled resonance splitting. Dynamic thermal optical effects due to linear absorption have been analyzed for each category as a function of the input power. The heat power in each resonator determines the thermal dynamics in this coupled resonator system. Multiple “shark fins” and power competition between resonators can be foreseen. Also, the nonlinear absorption induced thermal effects have been discussed.

  8. Serial grey-box model of a stratified thermal tank for hierarchical control of a solar plant

    Energy Technology Data Exchange (ETDEWEB)

    Arahal, Manuel R. [Universidad de Sevilla, Dpto. de Ingenieria de Sistemas y Automatica, Camino de los Descubrimientos s/n, 41092 Sevilla (Spain); Cirre, Cristina M. [Convenio Universidad de Almeria-Plataforma Solar de Almeria, Ctra. Senes s/n, 04200 Tabernas, Almeria (Spain); Berenguel, Manuel [Universidad de Almeria, Dpto. Lenguajes y Computacion, Ctra. Sacramento s/n, 04120, Almeria (Spain)

    2008-05-15

    The ACUREX collector field together with a thermal storage tank and a power conversion system forms the Small Solar Power Systems plant of the Plataforma Solar de Almeria, a facility that has been used for research for the last 25 years. A simulator of the collector field produced by the last author has been available to and used as a test-bed for control strategies. Up to now, however, there is not a model for the whole plant. Such model is needed for hierarchical control schemes also proposed by the authors. In this paper a model of the thermal storage tank is derived using the Simultaneous Perturbation Stochastic Approximation technique to adjust the parameters of a serial grey-box model structure. The benefits of the proposed approach are discussed in the context of the intended use, requiring a model capable of simulating the behavior of the storage tank with low computational load and low error over medium to large horizons. The model is tested against real data in a variety of situations showing its performance in terms of simulation error in the temperature profile and in the usable energy stored in the tank. The results obtained demonstrate the viability of the proposed approach. (author)

  9. Nonlinear Thermal Effects in Ballistic Electron Devices

    Science.gov (United States)

    2013-03-01

    Example 1: Rectified heat flow in Peltier coolers, or in thermal management. In Peltier coolers, an applied electric current removes heat from a...material, such that it can be cooled below ambient temperature. The performance of Peltier coolers is limited by the backflow of heat, in a direction

  10. Geometric nonlinear formulation for thermal-rigid-flexible coupling system

    Science.gov (United States)

    Fan, Wei; Liu, Jin-Yang

    2013-10-01

    This paper develops geometric nonlinear hybrid formulation for flexible multibody system with large deformation considering thermal effect. Different from the conventional formulation, the heat flux is the function of the rotational angle and the elastic deformation, therefore, the coupling among the temperature, the large overall motion and the elastic deformation should be taken into account. Firstly, based on nonlinear strain-displacement relationship, variational dynamic equations and heat conduction equations for a flexible beam are derived by using virtual work approach, and then, Lagrange dynamics equations and heat conduction equations of the first kind of the flexible multibody system are obtained by leading into the vectors of Lagrange multiplier associated with kinematic and temperature constraint equations. This formulation is used to simulate the thermal included hub-beam system. Comparison of the response between the coupled system and the uncoupled system has revealed the thermal chattering phenomenon. Then, the key parameters for stability, including the moment of inertia of the central body, the incident angle, the damping ratio and the response time ratio, are analyzed. This formulation is also used to simulate a three-link system applied with heat flux. Comparison of the results obtained by the proposed formulation with those obtained by the approximate nonlinear model and the linear model shows the significance of considering all the nonlinear terms in the strain in case of large deformation. At last, applicability of the approximate nonlinear model and the linear model are clarified in detail.

  11. Thermal Rectification in Graded Nonlinear Transmission Lines

    Institute of Scientific and Technical Information of China (English)

    许文; 陈伟中; 陶锋

    2011-01-01

    We consider heat conduction in a nonlinear inductance-capacitance(LC)transmission line with an inductance gradient by adding white-noise signals.It is found that the heat flux in the direction of inductance decrease is larger than that in the direction of inductance increase.When the low-inductance end is at higher temperature,the phonon density decreases due to conversion to high-frequency phonons,which can not move to the high-inductance end due to its lower cutoff frequency.However,when the high-inductance end is at higher temperature,the loss of phonon density can be compensated for because some high-frequency phonons can move to the low-inductance end dur to its higher cutoff frequency.This leads to the asymmetry of energy transfer.Discussion shows that this asymmetry exists in a particular range of temperatures,and increases with the increase of the difference between heat baths and the inductance gradient.%We consider heat conduction in a nonlinear inductance-capacitance (LC) transmission line with an inductance gradient by adding white-noise signals. It is found that the heat flux in the direction of inductance decrease is larger than that in the direction of inductance increase. When the low-inductance end is at higher temperature, the phonon density decreases due to conversion to high-frequency phonons, which can not move to the high-inductance end due to its lower cutoff frequency. However, when the high-inductance end is at higher temperature, the loss of phonon density can be compensated for because some high-frequency phonons can move to the low-inductance end dur to its higher cutoff frequency. This leads to the asymmetry of energy transfer. Discussion shows that this asymmetry exists in a particular range of temperatures, and increases with the increase of the difference between heat baths and the inductance gradient.

  12. A mechanical-thermal noise analysis of a nonlinear microgyroscope

    Science.gov (United States)

    Lajimi, S. A. M.; Heppler, G. R.; Abdel-Rahman, E. M.

    2017-01-01

    The mechanical-thermal noise (MTN) equivalent rotation rate (Ωn) is computed by using the linear approximation of the system response and the nonlinear "slow" system. The slow system, which is obtained using the method of multiple scales, is used to identify the linear single-valued response of the system. The linear estimate of the noise equivalent rate fails as the drive direction stroke increases. It becomes imperative in these conditions to use a more complex nonlinear estimate of the noise equivalent rate developed here for the first time in literature. The proposed design achieves a high performance regarding noise equivalent rotation rate.

  13. Thermal conductivity of nonlinear waves in disordered chains

    Indian Academy of Sciences (India)

    Sergej Flach; Mikhail Ivanchenko; Nianbei Li

    2011-11-01

    We present computational data on the thermal conductivity of nonlinear waves in disordered chains. Disorder induces Anderson localization for linear waves and results in a vanishing conductivity. Cubic nonlinearity restores normal conductivity, but with a strongly temperature-dependent conductivity (). We find indications for an asymptotic low-temperature ∼ 4 and intermediate temperature ∼ 2 laws. These findings are in accord with theoretical studies of wave packet spreading, where a regime of strong chaos is found to be intermediate, followed by an asymptotic regime of weak chaos (Laptyeva et al, Europhys. Lett. 91, 30001 (2010)).

  14. Optimal planning of co-firing alternative fuels with coal in a power plant by grey nonlinear mixed integer programming model.

    Science.gov (United States)

    Ko, Andi Setiady; Chang, Ni-Bin

    2008-07-01

    Energy supply and use is of fundamental importance to society. Although the interactions between energy and environment were originally local in character, they have now widened to cover regional and global issues, such as acid rain and the greenhouse effect. It is for this reason that there is a need for covering the direct and indirect economic and environmental impacts of energy acquisition, transport, production and use. In this paper, particular attention is directed to ways of resolving conflict between economic and environmental goals by encouraging a power plant to consider co-firing biomass and refuse-derived fuel (RDF) with coal simultaneously. It aims at reducing the emission level of sulfur dioxide (SO(2)) in an uncertain environment, using the power plant in Michigan City, Indiana as an example. To assess the uncertainty by a comparative way both deterministic and grey nonlinear mixed integer programming (MIP) models were developed to minimize the net operating cost with respect to possible fuel combinations. It aims at generating the optimal portfolio of alternative fuels while maintaining the same electricity generation simultaneously. To ease the solution procedure stepwise relaxation algorithm was developed for solving the grey nonlinear MIP model. Breakeven alternative fuel value can be identified in the post-optimization stage for decision-making. Research findings show that the inclusion of RDF does not exhibit comparative advantage in terms of the net cost, albeit relatively lower air pollution impact. Yet it can be sustained by a charge system, subsidy program, or emission credit as the price of coal increases over time.

  15. Thermally Induced Nonlinear Optical Absorption in Metamaterial Perfect Absorbers

    CERN Document Server

    Guddala, Sriram; Ramakrishna, S Anantha

    2015-01-01

    A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks is fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak resonant absorbance at 1090 nm and showed nonlinear absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation of reflectance was measured to be dependent on the average laser power incident and not the peak laser intensity. The nonlinear behaviour is shown to arise from the heating due to the absorbed radiation and photo-thermal changes in the dielectric properties of aluminium. The metamaterial absorber is seen to be damage resistant at large laser intensities of 25 MW/cm2.

  16. Nonlinear effect induced in thermally poled glass waveguides

    Institute of Scientific and Technical Information of China (English)

    REN Yi-tao

    2006-01-01

    Thermally poled germanium-doped channel waveguides are presented. Multilayer waveguides containing a silicon oxynitride layer were used as charge trapper in this investigation on the effect of the internal field inside the waveguide. Compared to waveguides without the trapping layer, experimental results showed that the induced linear electro-optic (EO) coefficient increases about 20% after poling, suggesting strongly that the internal field is relatively enhanced, and showed it is a promising means for improving nonlinearity by poling in waveguides.

  17. Thermal conductivities of some novel nonlinear optical materials.

    Science.gov (United States)

    Beasley, J D

    1994-02-20

    Results of thermal conductivity measurements are reported for several of the more recently developed nonlinear optical crystals. New or substantially revised values of thermal conductivity were obtained in six materials. Notable thermal conductivities measured were those for AgGaS(2) [0.014 W/(cm K) and 0.015 W/(cm K)], AgGaSe(2) [0.010 W/(cm K) and 0.011 W/(cm K)], beta barium borate [0.016 W/(cm K) and 0.012 W/(cm K)], and ZnGeP(2) [0.36 W/(cm K) and 0.35 W/(cm K)], with values quoted for directions respectively parallel and perpendicular to the optic axis for each material. These new data provide necessary input for the design of high-power optical frequency converters.

  18. Nonlinear Particle Acceleration and Thermal Particles in GRB Afterglows

    Science.gov (United States)

    Warren, Donald C.; Ellison, Donald C.; Barkov, Maxim V.; Nagataki, Shigehiro

    2017-02-01

    The standard model for GRB afterglow emission treats the accelerated electron population as a simple power law, N(E)\\propto {E}-p for p≳ 2. However, in standard Fermi shock acceleration, a substantial fraction of the swept-up particles do not enter the acceleration process at all. Additionally, if acceleration is efficient, then the nonlinear back-reaction of accelerated particles on the shock structure modifies the shape of the nonthermal tail of the particle spectra. Both of these modifications to the standard synchrotron afterglow impact the luminosity, spectra, and temporal variation of the afterglow. To examine the effects of including thermal particles and nonlinear particle acceleration on afterglow emission, we follow a hydrodynamical model for an afterglow jet and simulate acceleration at numerous points during the evolution. When thermal particles are included, we find that the electron population is at no time well fitted by a single power law, though the highest-energy electrons are; if the acceleration is efficient, then the power-law region is even smaller. Our model predicts hard–soft–hard spectral evolution at X-ray energies, as well as an uncoupled X-ray and optical light curve. Additionally, we show that including emission from thermal particles has drastic effects (increases by factors of 100 and 30, respectively) on the observed flux at optical and GeV energies. This enhancement of GeV emission makes afterglow detections by future γ-ray observatories, such as CTA, very likely.

  19. Logarithmic divergent thermal conductivity in two-dimensional nonlinear lattices.

    Science.gov (United States)

    Wang, Lei; Hu, Bambi; Li, Baowen

    2012-10-01

    Heat conduction in three two-dimensional (2D) momentum-conserving nonlinear lattices are numerically calculated via both nonequilibrium heat-bath and equilibrium Green-Kubo algorithms. It is expected by mainstream theories that heat conduction in such 2D lattices is divergent and the thermal conductivity κ increases with lattice length N logarithmically. Our simulations for the purely quartic lattice firmly confirm it. However, very robust finite-size effects are observed in the calculations for the other two lattices, which well explain some existing studies and imply the extreme difficulties in observing their true asymptotic behaviors with affordable computation resources.

  20. Elimination of Nonlinear Deviations in Thermal Lattice BGK Models

    CERN Document Server

    Chen, Y; Hongo, T; Chen, Yu; Ohashi, Hirotada; Akiyam, Mamoru

    1993-01-01

    Abstracet: We present a new thermal lattice BGK model in D-dimensional space for the numerical calculation of fluid dynamics. This model uses a higher order expansion of equilibrium distribution in Maxwellian type. In the mean time the lattice symmetry is upgraded to ensure the isotropy of 6th order tensor. These manipulations lead to macroscopic equations free from nonlinear deviations. We demonstrate the improvements by conducting classical Chapman-Enskog analysis and by numerical simulation of shear wave flow. The transport coefficients are measured numerically, too.

  1. Thermal rectification in non-linear structures with bulk losses

    Science.gov (United States)

    Schmidt, Martin; Kottos, Tsampikos

    2013-03-01

    A mechanism for thermal rectification based on the interplay between non-uniform bulk losses with nonlinearity is presented. We theoretically analyze the phenomenon using an anharmonic array of coupled oscillators coupled to the left and right with two Langevin reservoirs. A third probe thermostat (with temperature TB) is placed in an asymmetric position in the bulk of the lattice thus breaking the translational symmetry and leading to rectification of heat flow. We note that for TB = 0 this Langevin term is equivalent to a simple friction. We find that an increase of the friction strength can increase both the asymmetry and heat flux. Visiting Student from Germany

  2. Influence of thermal effects induced by nonlinear absorption on four-wave mixing in silicon waveguides

    DEFF Research Database (Denmark)

    Pu, Minhao; Chen, Yaohui; Yvind, Kresten

    2014-01-01

    Influence of thermal effects induced by nonlinear absorption on four-wave mixing in silicon waveguides is investigated. A conversion bandwidth reduction up to 63% is observed in simulation due to the thermal effects.......Influence of thermal effects induced by nonlinear absorption on four-wave mixing in silicon waveguides is investigated. A conversion bandwidth reduction up to 63% is observed in simulation due to the thermal effects....

  3. Molecular structure-property correlations from optical nonlinearity and thermal-relaxation dynamics.

    Science.gov (United States)

    Bhattacharyya, Indrajit; Priyadarshi, Shekhar; Goswami, Debabrata

    2009-02-01

    We apply ultrafast single beam Z-scan technique to measure saturation absorption coefficients and nonlinear-refraction coefficients of primary alcohols at 1560 nm. The nonlinear effects result from vibronic transitions and cubic nonlinear-refraction. To measure the pure total third-order nonlinear susceptibility, we removed thermal effects with a frequency optimized optical-chopper. Our measurements of thermal-relaxation dynamics of alcohols, from 1560 nm thermal lens pump and 780 nm probe experiments revealed faster and slower thermal-relaxation timescales, respectively, from conduction and convection. The faster timescale accurately predicts thermal-diffusivity, which decreases linearly with alcohol chain-lengths since thermal-relaxation is slower in heavier molecules. The relation between thermal-diffusivity and alcohol chain-length confirms structure-property relationship.

  4. Discriminating thermal effect in nonlinear-ellipse-rotation-modified Z-scan measurements.

    Science.gov (United States)

    Liu, Zhi-Bo; Shi, Shuo; Yan, Xiao-Qing; Zhou, Wen-Yuan; Tian, Jian-Guo

    2011-06-01

    We report that a modified Z-scan method by nonlinear ellipse rotation (NER) can be used to discriminate true nonlinear refraction from thermal effect in the transient regime and steady state. The combination of Z-scan and NER allows us to measure the third-order nonlinear susceptibility component without the influence of thermal-optical nonlinearity. The experimental results of pure CS(2) and CS(2) solutions of nigrosine verify that the transient thermal effect can be successfully eliminated from the NER-modified Z-scan measurements. This method is also extended to the case in which thermal-optical nonlinearities depend on a high repetition rate of femtosecond laser pulses for the N,N-dimethylmethanamide solutions of graphene oxide. © 2011 Optical Society of America

  5. A Taylor-Galerkin finite element algorithm for transient nonlinear thermal-structural analysis

    Science.gov (United States)

    Thornton, E. A.; Dechaumphai, P.

    1986-01-01

    A Taylor-Galerkin finite element method for solving large, nonlinear thermal-structural problems is presented. The algorithm is formulated for coupled transient and uncoupled quasistatic thermal-structural problems. Vectorizing strategies ensure computational efficiency. Two applications demonstrate the validity of the approach for analyzing transient and quasistatic thermal-structural problems.

  6. A generalized hybrid transfinite element computational approach for nonlinear/linear unified thermal/structural analysis

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    The present paper describes the development of a new hybrid computational approach for applicability for nonlinear/linear thermal structural analysis. The proposed transfinite element approach is a hybrid scheme as it combines the modeling versatility of contemporary finite elements in conjunction with transform methods and the classical Bubnov-Galerkin schemes. Applicability of the proposed formulations for nonlinear analysis is also developed. Several test cases are presented to include nonlinear/linear unified thermal-stress and thermal-stress wave propagations. Comparative results validate the fundamental capablities of the proposed hybrid transfinite element methodology.

  7. Nonlinear Companding Circuits With Thermal Compensation to Enhance Input Dynamic Range in Analog Optical Fiber Links

    Directory of Open Access Journals (Sweden)

    J. Rodríguez-Rodriguez

    2011-04-01

    Full Text Available Measuring systems based on a pair of optical fiber transmitter-receivers are used in medium-voltage testinglaboratories wherein the environment of high electromagnetic interference (EMI is a limitation for using conventionalcabling. Nonlinear compensation techniques have been used to limit the voltage range at the input of optical fiberlinks. However, nonlinear compensation introduces gain and linearity errors caused by thermal drift. This paperpresents a method of thermal compensation for the nonlinear circuit used to improve transient signal handlingcapabilities in measuring system while maintaining low errors in gain and linearity caused by thermal drift.

  8. Thermal entanglement in 1D optical lattice chains with nonlinear coupling

    Institute of Scientific and Technical Information of China (English)

    Zhou Ling; Yi Xue-Xi; Song He-Shan; Guo Yan-Qing

    2005-01-01

    he thermal entanglement of spin-1 atoms with nonlinear coupling in an optical lattice chain is investigated for two-particle and multi-particle systems. It is found that the relation between linear coupling and nonlinear coupling is the key to determine thermal entanglement, which shows in what kinds of atoms thermal entanglement exists. This result is true both for two-particle and multi-particle systems. For multi-particle systems, the thermal entanglement does not decrease greatly, and the critical temperature decreases only slightly.

  9. Observation of nonlinear thermal optical dynamics in a chalcogenide nanobeam cavity

    CERN Document Server

    Sun, Yue; Choi, Duk-Yong; Sukhorukov, Andrey A

    2016-01-01

    We present a theoretical and experimental analysis of nonlinear thermo-optic effects in suspended chalcogenide glass nanobeam cavities. We measure the power dependent resonance peaks and characterise the dynamic nonlinear thermo-optic response of the cavity under modulated light input. Several distinct nonlinear characteristics are identified, including a modified spectral response containing periodic fringes, a critical wavelength jump and saturated time delay for modulation frequency faster than the thermal characteristic time. We reveal that the coupling to a parasitic Fabry-Perot cavity enables isolated thermal equilibrium states resulting in the discontinuous thermo-optic critical point.

  10. On high-continuity transfinite element formulations for linear-nonlinear transient thermal problems

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1987-01-01

    This paper describes recent developments in the applicability of a hybrid transfinite element methodology with emphasis on high-continuity formulations for linear/nonlinear transient thermal problems. The proposed concepts furnish accurate temperature distributions and temperature gradients making use of a relatively smaller number of degrees of freedom; and the methodology is applicable to linear/nonlinear thermal problems. Characteristic features of the formulations are described in technical detail as the proposed hybrid approach combines the major advantages and modeling features of high-continuity thermal finite elements in conjunction with transform methods and classical Galerkin schemes. Several numerical test problems are evaluated and the results obtained validate the proposed concepts for linear/nonlinear thermal problems.

  11. Grey water biodegradability

    NARCIS (Netherlands)

    Abu Ghunmi, L.; Zeeman, G.; Fayyad, M.; Lier, van J.B.

    2011-01-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different condi

  12. Grey water biodegradability

    NARCIS (Netherlands)

    Abu Ghunmi, L.; Zeeman, G.; Fayyad, M.; Van Lier, J.B.

    2010-01-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different condi

  13. Effect of quantum correction on nonlinear thermal wave of electrons driven by laser heating

    Science.gov (United States)

    Nafari, F.; Ghoranneviss, M.

    2016-08-01

    In thermal interaction of laser pulse with a deuterium-tritium (DT) plane, the thermal waves of electrons are generated instantly. Since the thermal conductivity of electron is a nonlinear function of temperature, a nonlinear heat conduction equation is used to investigate the propagation of waves in solid DT. This paper presents a self-similar analytic solution for the nonlinear heat conduction equation in a planar geometry. The thickness of the target material is finite in numerical computation, and it is assumed that the laser energy is deposited at a finite initial thickness at the initial time which results in a finite temperature for electrons at initial time. Since the required temperature range for solid DT ignition is higher than the critical temperature which equals 35.9 eV, the effects of quantum correction in thermal conductivity should be considered. This letter investigates the effects of quantum correction on characteristic features of nonlinear thermal wave, including temperature, penetration depth, velocity, heat flux, and heating and cooling domains. Although this effect increases electron temperature and thermal flux, penetration depth and propagation velocity are smaller. This effect is also applied to re-evaluate the side-on laser ignition of uncompressed DT.

  14. Nonlinear continuous-wave optical propagation in nematic liquid crystals: Interplay between reorientational and thermal effects

    Science.gov (United States)

    Alberucci, Alessandro; Laudyn, Urszula A.; Piccardi, Armando; Kwasny, Michał; Klus, Bartlomiej; Karpierz, Mirosław A.; Assanto, Gaetano

    2017-07-01

    We investigate nonlinear optical propagation of continuous-wave (CW) beams in bulk nematic liquid crystals. We thoroughly analyze the competing roles of reorientational and thermal nonlinearity with reference to self-focusing/defocusing and, eventually, the formation of nonlinear diffraction-free wavepackets, the so-called spatial optical solitons. To this extent we refer to dye-doped nematic liquid crystals in planar cells excited by a single CW beam in the highly nonlocal limit. To adjust the relative weight between the two nonlinear responses, we employ two distinct wavelengths, inside and outside the absorption band of the dye, respectively. Different concentrations of the dye are considered in order to enhance the thermal effect. The theoretical analysis is complemented by numerical simulations in the highly nonlocal approximation based on a semi-analytic approach. Theoretical results are finally compared to experimental results in the Nematic Liquid Crystals (NLC) 4-trans-4'-n-hexylcyclohexylisothiocyanatobenzene (6CHBT) doped with Sudan Blue dye.

  15. Entanglement dynamics of quantum oscillators nonlinearly coupled to thermal environments

    Science.gov (United States)

    Voje, Aurora; Croy, Alexander; Isacsson, Andreas

    2015-07-01

    We study the asymptotic entanglement of two quantum harmonic oscillators nonlinearly coupled to an environment. Coupling to independent baths and a common bath are investigated. Numerical results obtained using the Wangsness-Bloch-Redfield method are supplemented by analytical results in the rotating wave approximation. The asymptotic negativity as function of temperature, initial squeezing, and coupling strength, is compared to results for systems with linear system-reservoir coupling. We find that, due to the parity-conserving nature of the coupling, the asymptotic entanglement is considerably more robust than for the linearly damped cases. In contrast to linearly damped systems, the asymptotic behavior of entanglement is similar for the two bath configurations in the nonlinearly damped case. This is due to the two-phonon system-bath exchange causing a suppression of information exchange between the oscillators via the bath in the common-bath configuration at low temperatures.

  16. Thermostatistics of small nonlinear systems: Gaussian thermal bath.

    Science.gov (United States)

    Morgado, Welles A M; Duarte Queirós, Sílvio M

    2014-08-01

    We discuss the statistical properties of small mechanothermodynamic systems (one- and two-particle cases) subject to nonlinear coupling and in contact with standard Gaussian reservoirs. We use a method that applies averages in the Laplace-Fourier space, which relates to a generalization of the final-value theorem. The key advantage of this method lies in the possibility of eschewing the explicit computation of the propagator, traditionally required in alternative methods like path integral calculations, which is hardly obtainable in the majority of the cases. For one-particle equilibrium systems we are able to compute the instantaneous (equilibrium) probability density functions of injected and dissipated power as well as the respective large deviation functions. Our thorough calculations explicitly show that for such models nonlinearities are irrelevant in the long-term statistics, which preserve the exact same values as computed for linear cases. Actually, we verify that the thermostatistical effect of the nonlinearities is constricted to the transient towards equilibrium, since it affects the average total energy of the system. For the two-particle system we consider each element in contact with a heat reservoir, at different temperatures, and focus on the problem of heat flux between them. Contrarily to the one-particle case, in this steady state nonequilibrium model we prove that the heat flux probability density function reflects the existence of nonlinearities in the system. An important consequence of that it is the temperature dependence of the conductance, which is unobserved in linear(harmonic) models. Our results are complemented by fluctuation relations for the injected power (equilibrium case) and heat flux (nonequilibrium case).

  17. Entanglement Dynamics of Quantum Oscillators Nonlinearly Coupled to Thermal Environments

    OpenAIRE

    Voje, Aurora; Croy, Alexander; Isacsson, Andreas

    2014-01-01

    We study the asymptotic entanglement of two quantum harmonic oscillators nonlinearly coupled to an environment. Coupling to independent baths and a common bath are investigated. Numerical results obtained using the Wangsness-Bloch-Redfield method are supplemented by analytical results in the rotating wave approximation. The asymptotic negativity as function of temperature, initial squeezing and coupling strength, is compared to results for systems with linear system-reservoir coupling. We fin...

  18. A new method of thermal network modeling - A nonlinear programming approach

    Science.gov (United States)

    Adachi, M.; Miyaoka, S.; Muramatsu, A.; Funabashi, M.; Nakajima, T.

    A new method for correcting thermal network model coefficients is described. This method sharply reduces discrepancies obtained by the nonlinear programming approach in the conductance coefficients and radiation coefficients for determining the heat balance of a spacecraft. The method consists of an experimental design and a nonlinear parameter identification. An experimental design for obtaining useful data for the thermal network model correction is discussed. A simulation study has shown that the standard deviation of the estimated temperature and estimation error of the parameters are reduced by 50 percent and 70 percent respectively.

  19. HYBRID GREY WOLF OPTIMIZATION-PATTERN SEARCH (hGWO-PS OPTIMIZED 2DOF-PID CONTROLLERS FOR LOAD FREQUENCY CONTROL (LFC IN INTERCONNECTED THERMAL POWER PLANTS

    Directory of Open Access Journals (Sweden)

    V Soni

    2016-04-01

    Full Text Available The combination of Grey Wolf Optimization and Pattern Search Technique (hGWO-PS has been introduced to optimize the parameters of two Degree of Freedom Proportional-Integral-Derivative Controller (2DOF-PID for controlling the load frequency in Automatic Generation Control (AGC for interconnected power system. The interconnected two area power system of non-reheat thermal power plants consisting of 2DOF-PID controller in each area has been considered for design and analysis. Firstly, the proposed approach has been implemented in the aforementioned standard test system and thereafter, the robustness of the system consisting 2DOF-PID controller optimized by proposed technique has been estimated using the sensitivity analysis for the same. The robustness of the system consisting of 2DOF-PID controller optimized by proposed scheme is examined by varying the parameters of standard test system, loading conditions during operation, size and location of the disturbances. The performance of the 2DOF-PID controller optimized by proposed approach has also been compared with recently published approaches in the literature. The simulation results show that the proposed hGWOPS optimized 2DOF-PID controller shows far better performance than recently published approaches in the literature in terms of dynamic response. The simulation results also show that system performances hardly change when the operating load condition and system parameters are changed by ±50% from their nominal values, i.e. the proposed controllers are quite robust for a wide range of the system parameters and operating load conditions from their nominal values.

  20. MHD three-dimensional flow of nanofluid with velocity slip and nonlinear thermal radiation

    Science.gov (United States)

    Hayat, Tasawar; Imtiaz, Maria; Alsaedi, Ahmed; Kutbi, Marwan A.

    2015-12-01

    An analysis has been carried out for the three dimensional flow of viscous nanofluid in the presence of partial slip and thermal radiation effects. The flow is induced by a permeable stretching surface. Water is treated as a base fluid and alumina as a nanoparticle. Fluid is electrically conducting in the presence of applied magnetic field. Entire different concept of nonlinear thermal radiation is utilized in the heat transfer process. Different from the previous literature, the nonlinear system for temperature distribution is solved and analyzed. Appropriate transformations reduce the nonlinear partial differential system to ordinary differential system. Convergent series solutions are computed for the velocity and temperature. Effects of different parameters on the velocity, temperature, skin friction coefficient and Nusselt number are computed and examined. It is concluded that heat transfer rate increases when temperature and radiation parameters are increased.

  1. Nonlinear stability analysis of double-curved shallow fgm panels on elastic foundations in thermal environments

    Science.gov (United States)

    Duc, Nguyen Dinh; Quan, Tran Quoc

    2012-09-01

    An analytical investigation into the nonlinear response of thick functionally graded double-curved shallow panels resting on elastic foundations and subjected to thermal and thermomechanical loads is presented. Young's modulus and Poisson's ratio are both graded in the thickness direction according to a simple power-law distribution in terms of volume fractions of constituents. All formulations are based on the classical shell theory with account of geometrical nonlinearity and initial geometrical imperfection in the cases of Pasternak-type elastic foundations. By applying the Galerkin method, explicit relations for the thermal load-deflection curves of simply supported curved panels are found. The effects of material and geometrical properties and foundation stiffness on the buckling and postbuckling load-carrying capacity of the panels in thermal environments are analyzed and discussed.

  2. Thermally Stable Heterocyclic Imines as New Potential Nonlinear Optical Materials

    Science.gov (United States)

    Nesterov, Volodymyr V.; Antipin, Mikhail Y.; Nesterov, Vladimir N.; Moore, Craig E.; Cardelino, Beatriz H.; Timofeeva, Tatiana V.

    2004-01-01

    In the course of a search for new thermostable acentric nonlinear optical crystalline materials, several heterocyclic imine derivatives were designed, with the general structure D-pi-A(D'). Introduction of a donor amino group (D') into the acceptor moiety was expected to bring H-bonds into their crystal structures, and so to elevate their melting points and assist in an acentric molecular packing. Six heterocycle-containing compounds of this type were prepared, single crystals were grown for five of them, and these crystals were characterized by X-ray analysis. A significant melting temperature elevation was found for all of the synthesized compounds. Three of the compounds were also found to crystallize in acentric space groups. One of the acentric compounds is built as a three-dimensional H-bonded molecular network. In the other two compounds, with very similar molecular structure, the molecules form one-dimensional H-bonded head-to-head associates (chains). These chains are parallel in two different crystallographic directions and form very unusual interpenetrating chain patterns in an acentric crystal. Two of the compounds crystallized with centrosymmetric molecular packing.

  3. Characteristics of grey wastewater

    DEFF Research Database (Denmark)

    Eriksson, Eva; Auffarth, Karina Pipaluk Solvejg; Henze, Mogens

    2002-01-01

    The composition of grey wastewater depends on sources and installations from where the water is drawn, e.g. kitchen, bathroom or laundry. The chemical compounds present originate from household chemicals, cooking, washing and the piping. In general grey wastewater contains lower levels of organic...

  4. Magnetohydrodynamic three-dimensional flow of viscoelastic nanofluid in the presence of nonlinear thermal radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, T. [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Faculty of Science, King Abdulaziz University, P. O. Box 80203, Jeddah 21589 (Saudi Arabia); Muhammad, Taseer, E-mail: taseer_qau@yahoo.com [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Alsaedi, A.; Alhuthali, M.S. [Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Faculty of Science, King Abdulaziz University, P. O. Box 80203, Jeddah 21589 (Saudi Arabia)

    2015-07-01

    Magnetohydrodynamic (MHD) three-dimensional flow of couple stress nanofluid in the presence of thermophoresis and Brownian motion effects is analyzed. Energy equation subject to nonlinear thermal radiation is taken into account. The flow is generated by a bidirectional stretching surface. Fluid is electrically conducting in the presence of a constant applied magnetic field. The induced magnetic field is neglected for a small magnetic Reynolds number. Mathematical formulation is performed using boundary layer analysis. Newly proposed boundary condition requiring zero nanoparticle mass flux is employed. The governing nonlinear mathematical problems are first converted into dimensionless expressions and then solved for the series solutions of velocities, temperature and nanoparticles concentration. Convergence of the constructed solutions is verified. Effects of emerging parameters on the temperature and nanoparticles concentration are plotted and discussed. Skin friction coefficients and Nusselt number are also computed and analyzed. It is found that the thermal boundary layer thickness is an increasing function of radiative effect. - Highlights: • Three-dimensional boundary layer flow of viscoelastic nanofluid is examined. • Nonlinear thermal radiation is analyzed. • Brownian motion and thermophoresis effects are present. • Recently developed condition requiring zero nanoparticle mass flux is implemented. • Construction of convergent solutions of nonlinear flow is possible.

  5. MHD three-dimensional flow of nanofluid with velocity slip and nonlinear thermal radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Tasawar [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Imtiaz, Maria, E-mail: mi_qau@yahoo.com [Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000 (Pakistan); Alsaedi, Ahmed; Kutbi, Marwan A. [Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2015-12-15

    An analysis has been carried out for the three dimensional flow of viscous nanofluid in the presence of partial slip and thermal radiation effects. The flow is induced by a permeable stretching surface. Water is treated as a base fluid and alumina as a nanoparticle. Fluid is electrically conducting in the presence of applied magnetic field. Entire different concept of nonlinear thermal radiation is utilized in the heat transfer process. Different from the previous literature, the nonlinear system for temperature distribution is solved and analyzed. Appropriate transformations reduce the nonlinear partial differential system to ordinary differential system. Convergent series solutions are computed for the velocity and temperature. Effects of different parameters on the velocity, temperature, skin friction coefficient and Nusselt number are computed and examined. It is concluded that heat transfer rate increases when temperature and radiation parameters are increased. - Highlights: • Three-dimensional nanofluid flow with partial slip and nonlinear thermal radiation is studied. • Increasing values of velocity slip parameter decrease the velocity profiles. • The temperature increases via larger nanoparticle volume fraction. • Surface temperature gradient increases for higher temperature and radiation parameters.

  6. Thermal instability and thermodynamic geometry of topological dilaton black holes coupled to nonlinear electrodynamics

    Science.gov (United States)

    Sheykhi, A.; Hajkhalili, S.

    2015-11-01

    We study topological dilaton black holes of Einstein gravity in the presence of exponential nonlinear electrodynamics. The event horizons of these black holes can be a two-dimensional positive, zero or negative constant curvature surface. We analyze thermodynamics of these solutions by calculating all conserved and thermodynamic quantities and showing that the first law holds on the black hole horizon. Then, we perform the stability analysis in both canonical and grand canonical ensemble and disclose the effects of the dilaton and nonlinear electrodynamics on the thermal stability of the solutions. Finally, we study the phase transition points of these black holes in the thermodynamic geometry approach.

  7. Free Convective Nonaligned Non-Newtonian Flow with Non-linear Thermal Radiation

    Science.gov (United States)

    Rana, S.; Mehmood, R.; Narayana, PV S.; Akbar, N. S.

    2016-12-01

    The present study explores the free convective oblique Casson fluid over a stretching surface with non-linear thermal radiation effects. The governing physical problem is modelled and transformed into a set of coupled non-linear ordinary differential equations by suitable similarity transformation, which are solved numerically with the help of shooting method keeping the convergence control of 10-5 in computations. Influence of pertinent physical parameters on normal, tangential velocity profiles and temperature are expressed through graphs. Physical quantities of interest such as skin friction coefficients and local heat flux are investigated numerically.

  8. Crystal growth and comparison of vibrational and thermal properties of semi-organic nonlinear optical materials

    Indian Academy of Sciences (India)

    S Gunasekaran; G Anand; R Arun Balaji; J Dhanalakshmi; S Kumaresan

    2010-10-01

    Single crystals of urea thiourea mercuric sulphate (UTHS) and urea thiourea mercuric chloride (UTHC), semi-organic nonlinear optical materials, were grown by low-temperature solution growth technique by slow evaporation method using water as the solvent. Good quality single crystals were grown within three weeks. The nonlinear nature of the crystals was confirmed by SHG test. The UV–Vis spectrum showed the transmitting ability of the crystals in the entire visible region. FTIR spectrum was recorded and vibrational assignments were made. The degree of dopant inclusion was ascertained by AAS. The TGA–DTA studies showed the thermal properties of the crystals.

  9. Active control and parameter updating techniques for nonlinear thermal network models

    Science.gov (United States)

    Papalexandris, M. V.; Milman, M. H.

    The present article reports on active control and parameter updating techniques for thermal models based on the network approach. Emphasis is placed on applications where radiation plays a dominant role. Examples of such applications are the thermal design and modeling of spacecrafts and space-based science instruments. Active thermal control of a system aims to approximate a desired temperature distribution or to minimize a suitably defined temperature-dependent functional. Similarly, parameter updating aims to update the values of certain parameters of the thermal model so that the output approximates a distribution obtained through direct measurements. Both problems are formulated as nonlinear, least-square optimization problems. The proposed strategies for their solution are explained in detail and their efficiency is demonstrated through numerical tests. Finally, certain theoretical results pertaining to the characterization of solutions of the problems of interest are also presented.

  10. Thermochemical ablation of carbon/carbon composites with non-linear thermal conductivity

    Directory of Open Access Journals (Sweden)

    Li Wei-Jie

    2014-01-01

    Full Text Available Carbon/carbon composites have been typically used to protect a rocket nozzle from high temperature oxidizing gas. Based on the Fourier’s law of heat conduction and the oxidizing ablation mechanism, the ablation model with non-linear thermal conductivity for a rocket nozzle is established in order to simulate the one-dimensional thermochemical ablation rate on the surface and the temperature distributions by using a written computer code. As the presented results indicate, the thermochemical ablation rate of a solid rocket nozzle calculated by using actual thermal conductivity, which is a function of temperature, is higher than that by a constant thermal conductivity, so the effect of thermal conductivity on the ablation rate of a solid rocket nozzle made of carbon/carbon composites cannot be neglected.

  11. Nonlinear free flexural vibrations of functionally graded rectangular and skew plates under thermal environments

    CERN Document Server

    Sundararajan, N; Ganapathi, M; 10.1016/j.finel.2005.06.001

    2011-01-01

    The nonlinear formulation developed based on von Karman's assumptions is employed to study the free vibration characteristics of functionally graded material (FGM) plates subjected to thermal environment. Temperature field is assumed to be a uniform distribution over the plate surface and varied in the thickness direction. The material is assumed to be temperature dependent and graded in the thickness direction according to the power-law distribution in terms of volume fractions of the constituents. The effective material properties are estimated from the volume fractions and the material properties of the constituents using Mori-Tanaka homogenization method. The nonlinear governing equations obtained using Lagrange's equations of motion are solved using finite element procedure coupled with the direct iteration technique. The variation of nonlinear frequency ratio with amplitude is highlighted considering various parameters such as gradient index, temperature, thickness and aspect ratios, and skew angle. For...

  12. All-plasmonic switching based on thermal nonlinearity in a polymer plasmonic microring resonator

    Science.gov (United States)

    Perron, David; Wu, Marcelo; Horvath, Cameron; Bachman, Daniel; van, Vien

    2011-07-01

    We experimentally investigated thermal nonlinear effects in a hybrid Au/SiO2/SU-8 plasmonic microring resonator for nonlinear switching. Large ohmic loss in the metal layer gave rise to a high rate of light-to-heat conversion in the plasmonic waveguide, causing an intensity-dependent thermo-optic shift in the microring resonance. We obtained 30 times larger resonance shift in the plasmonic microring than in a similar SU-8 dielectric microring. Using an in-plane pump-and-probe configuration, we also demonstrated all-plasmonic nonlinear switching in the plasmonic microring with an on--off switching contrast of 4dB over 50mW input power.

  13. Thermal and Transmission Properties of UV Nonlinear Optical Material-- ZnCd(SCN)4 Crystal

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Zinc cadmium thiocyanate(ZCTC), ZnCd(SCN)4, has been discovered as a UV second-order nonlinear optical coordination crystal. Its thermal and transmission properties are reported. The thermal decomposition is characterized by using the X-ray powder diffraction (XRPD) and infrared (IR) spectroscopy at room temperature. The absorptions of intrinsic ions and ZCTC in a solution state are discussed as well as transmission properties of the ZCTC crystal. An effective method of reducing the surface reflection loss of ZCTC crystal is introduced.

  14. Decoherence of a Quantum Nonlinear Oscillator Under a Non-zero Temperature Thermal Bath

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The characteristic time τD for decoherence process of a quantum nonlinear oscillator system under a nonzero temperature thermal bath is studied by expanding the linear entropy. By numerical analysis, it is shown that at a non-zero temperature, the quantum coherence decays much faster than at zero temperature. Moreover, the non-zero temperature thermal bath will bring a crucialsuppression to the quantum effects of the observables, which causes these quantum effects to become unable to persist up to the Ehrenfest time but is insufficient to destroy the quantum-classical transition.

  15. Uncertainty representation of grey numbers and grey sets.

    Science.gov (United States)

    Yang, Yingjie; Liu, Sifeng; John, Robert

    2014-09-01

    In the literature, there is a presumption that a grey set and an interval-valued fuzzy set are equivalent. This presumption ignores the existence of discrete components in a grey number. In this paper, new measurements of uncertainties of grey numbers and grey sets, consisting of both absolute and relative uncertainties, are defined to give a comprehensive representation of uncertainties in a grey number and a grey set. Some simple examples are provided to illustrate that the proposed uncertainty measurement can give an effective representation of both absolute and relative uncertainties in a grey number and a grey set. The relationships between grey sets and interval-valued fuzzy sets are also analyzed from the point of view of the proposed uncertainty representation. The analysis demonstrates that grey sets and interval-valued fuzzy sets provide different but overlapping models for uncertainty representation in sets.

  16. Thermochemical ablation of carbon/carbon composites with non-linear thermal conductivity

    OpenAIRE

    2014-01-01

    Carbon/carbon composites have been typically used to protect a rocket nozzle from high temperature oxidizing gas. Based on the Fourier’s law of heat conduction and the oxidizing ablation mechanism, the ablation model with non-linear thermal conductivity for a rocket nozzle is established in order to simulate the one-dimensional thermochemical ablation rate on the surface and the temperature distributions by using a written computer code. As the presented re...

  17. GreyGuide. Poster presentation

    OpenAIRE

    Biagioni, Stefania; Farace, Dominic

    2014-01-01

    Welcome to the GreyGuide, a repository of good practices and resources in grey literature. The GreyGuide seeks to capture proposed as well as published practices dealing with the supply and demand sides of grey literature. This is a collaborative project involving GreyNet International and ISTI-CNR. The launch of the GreyGuide Repository took place in December 2013 at the Fifteenth International Conference on Grey Literature. Since then, the acquisition of both proposed and published good pra...

  18. Grey Repairable System Analysis

    Institute of Scientific and Technical Information of China (English)

    Renkuan Guo; Charles Ernie Love

    2006-01-01

    In this paper, we systematically discuss the basic concepts of grey theory, particularly the grey differential equation and its mathematical foundation, which is essentially unknown in the reliability engineering community. Accordingly,we propose a small-sample based approach to estimate repair improvement effects by partitioning system stopping times into intrinsic functioning times and repair improvement times. An industrial data set is used for illustrative purposes in a stepwise manner.

  19. Grey Literature 2.0

    OpenAIRE

    Simandlová, Tereza

    2012-01-01

    The paper tries to describe grey literature in the context of platforms and tools of the web 2.0. We can follow up that increasing trends in the scientific communication are e.g. microblogging, scientific blogging and there are also scientific social networks in the distribution cycle of grey literature. Except the examples of grey literature 2.0, the paper also discusses the problems of the promotion of grey literature and grey literature community through the social media.

  20. Growth, spectral, optical, thermal, crystallization perfection and nonlinear optical studies of novel nonlinear optical crystal—Urea thiosemicarbazone monohydrate

    Science.gov (United States)

    Hanumantharao, Redrothu; Kalainathan, S.; Bhagavannarayana, G.

    2012-06-01

    Single crystals of organic nonlinear material urea thiosemicarbazone monohydrate (UTM) have been grown by slow evaporation method. The grown crystals were characterized by single crystal X-ray diffraction analysis reveals that sample crystallized in triclinic system with noncentrosymmetric space group P1. Powder XRD pattern confirmed that grown crystal posses highly crystalline nature. FTIR spectrum was recorded to identify the presence of functional groups and molecular structure was confirmed by 1H NMR spectrum. Material confirmation of title compound has been performed by using mass spectroscopic analysis. Elemental composition of grown crystal was confirmed by energy-dispersive spectrometry (EDS). To study the crystalline perfection of the grown crystals, high-resolution X-ray diffraction (HR-XRD) study was carried out. Thermogravimetric and differential thermal analyses were employed to understand the thermal and physio-chemical stability of the synthesized compound. UV-Vis-NIR spectrum revealed the transmission properties of the crystal specimen. Relative SHG efficiency is measured by Kurtz and Perry method and found to about 0.89 times that of standard potassium dihydrogen phosphate (KDP) crystals.

  1. Non-linear dual-phase-lag model for analyzing heat transfer phenomena in living tissues during thermal ablation.

    Science.gov (United States)

    Kumar, P; Kumar, Dinesh; Rai, K N

    2016-08-01

    In this article, a non-linear dual-phase-lag (DPL) bio-heat transfer model based on temperature dependent metabolic heat generation rate is derived to analyze the heat transfer phenomena in living tissues during thermal ablation treatment. The numerical solution of the present non-linear problem has been done by finite element Runge-Kutta (4,5) method which combines the essence of Runge-Kutta (4,5) method together with finite difference scheme. Our study demonstrates that at the thermal ablation position temperature predicted by non-linear and linear DPL models show significant differences. A comparison has been made among non-linear DPL, thermal wave and Pennes model and it has been found that non-linear DPL and thermal wave bio-heat model show almost same nature whereas non-linear Pennes model shows significantly different temperature profile at the initial stage of thermal ablation treatment. The effect of Fourier number and Vernotte number (relaxation Fourier number) on temperature profile in presence and absence of externally applied heat source has been studied in detail and it has been observed that the presence of externally applied heat source term highly affects the efficiency of thermal treatment method.

  2. LMI-based Research on Stability of Leagile Supply Chain with Grey Non-linear Characteristics%基于LMI的灰色非线性精敏供应链稳定性判定方法

    Institute of Scientific and Technical Information of China (English)

    张学龙; 王云峰

    2014-01-01

    平稳运行是精敏供应链管理的重要基础,针对具有区间灰色非线性特征的精敏供应链系统波动性的难题,以非线性时滞精敏供应链系统为研究基础,建立了灰色非线性精敏供应链系统,采用线性矩阵不等式算法分析其稳定性问题,并获取了一种灰色非线性精敏供应链系统的稳定性判定方法。为验证该方法的有效性和可行性,以医药行业YL集团核心产品的供应链系统为案例分析对象,通过观测两个时点的运行数据,使用Matlab7.0计算工具,得出[0,20]和[20,40]2个时间段供应链系统的稳定性状态变化图。并假设当客户订货分离点( CODP)下移时,运用同样的观测数据,模拟系统稳定性状态的变化。对比案例分析的结果得出结论:随着CODP从精敏供应链的上游端在下移至下游端时,不仅仅体现的是供应链系统类型的改变,而且更重要的是揭示了精益供应链和敏捷供应链稳定性的影响因素不同,前者受订单量大小程度的影响,而后者由市场需求预测的准确性程度决定。%In leagile supply chain management , it is important to operate a supply chain smoothly .Howev-er, with grey and non-linearity, it is very challenging to model and control such a supply chain .On the basis of non-linear and time delay leagile supply chain systems , a grey and non-linear model is developed for a leagile supply chain .Then, a linear matrix inequality method is used to analyze its stability and an effective stability criterion is obtained .In order to verify the feasibility and effectiveness of the proposed method, a core product supply chain systems of YL Group in the medicine industry is used as a case stud -y.By using Matlab 7.0, the stability of the system state diagram is drawn before and after customer order decoupling point ( CODP) .Results show that when CODP moves down , not only the supply chain type is changed but

  3. Nonlinear thermal convection in a viscoelastic nanofluid saturated porous medium under gravity mod

    Directory of Open Access Journals (Sweden)

    Palle Kiran

    2016-06-01

    Full Text Available This paper carried out a nonlinear thermal convection in a porous medium saturated with viscoelastic nanofluid under vibrations. The Darcy model has been used for the porous medium, while the nanofluid layer incorporates the effect of Brownian motion along with thermophoresis. An Oldroyd-B type constitutive equation was used to describe the rheological behavior of viscoelastic nanofluids. The non-uniform vertical vibrations of the system, which can be realized by oscillating the system vertically, is considered to vary sinusoidally with time. In order to find the heat and mass transports for unsteady state, a nonlinear analysis, using a minimal representation of the truncated Fourier series of two terms, has been performed. Effect of various parameters has been investigated on heat and mass transport and then presented graphically. It is found that gravity modulation can be used effectively to regulate either heat or mass transports in the system.

  4. Computer program for nonlinear static stress analysis of shuttle thermal protection system: User's manual

    Science.gov (United States)

    Giles, G. L.; Wallas, M.

    1981-01-01

    User documentation is presented for a computer program which considers the nonlinear properties of the strain isolator pad (SIP) in the static stress analysis of the shuttle thermal protection system. This program is generalized to handle an arbitrary SIP footprint including cutouts for instrumentation and filler bar. Multiple SIP surfaces are defined to model tiles in unique locations such as leading edges, intersections, and penetrations. The nonlinearity of the SIP is characterized by experimental stress displacement data for both normal and shear behavior. Stresses in the SIP are calculated using a Newton iteration procedure to determine the six rigid body displacements of the tile which develop reaction forces in the SIP to equilibrate the externally applied loads. This user documentation gives an overview of the analysis capabilities, a detailed description of required input data and an example to illustrate use of the program.

  5. Thermal stability analysis of nonlinearly charged asymptotic AdS black hole solutions

    Science.gov (United States)

    Dehghani, M.; Hamidi, S. F.

    2017-08-01

    In this paper, the four-dimensional nonlinearly charged black hole solutions have been considered in the presence of the power Maxwell invariant electrodynamics. Two new classes of anti-de Sitter (AdS) black hole solutions have been introduced according to different amounts of the parameters in the nonlinear theory of electrodynamics. The conserved and thermodynamical quantities of either of the black hole classes have been calculated from geometrical and thermodynamical approaches, separately. It has been shown that the first law of black hole thermodynamics is satisfied for either of the AdS black hole solutions we just obtained. Through the canonical and grand canonical ensemble methods, the black hole thermal stability or phase transitions have been analyzed by considering the heat capacities with the fixed black hole charge and fixed electric potential, respectively. It has been found that the new AdS black holes are stable if some simple conditions are satisfied.

  6. Transfinite element methodology for nonlinear/linear transient thermal modelling/analysis - Progress and recent advances

    Science.gov (United States)

    Tamma, Kumar K.; Railkar, Sudhir B.

    1988-01-01

    The 'transfinite element method' (TFEM) proposed by Tamma and Railkar (1987 and 1988) for the analysis of linear and nonlinear heat-transfer problems is described and demonstrated. The TFEM combines classical Galerkin and transform approaches with state-of-the-art FEMs to obtain a flexible hybrid modeling scheme. The fundamental principles of the TFEM and the derivation of the governing equations are reviewed, and numerical results for sample problems are presented in extensive graphs and briefly characterized. Problems analyzed include a square plate with a hole, a rectangular plate with natural and essential boundary conditions and varying thermal conductivity, the Space Shuttle thermal protection system, a bimaterial plate subjected to step temperature variations, and solidification in a semiinfinite liquid slab.

  7. Modelling of hydrogen thermal desorption spectrum in nonlinear dynamical boundary-value problem

    Science.gov (United States)

    Kostikova, E. K.; Zaika, Yu V.

    2016-11-01

    One of the technological challenges for hydrogen materials science (including the ITER project) is the currently active search for structural materials with various potential applications that will have predetermined limits of hydrogen permeability. One of the experimental methods is thermal desorption spectrometry (TDS). A hydrogen-saturated sample is degassed under vacuum and monotone heating. The desorption flux is measured by mass spectrometer to determine the character of interactions of hydrogen isotopes with the solid. We are interested in such transfer parameters as the coefficients of diffusion, dissolution, desorption. The paper presents a distributed boundary-value problem of thermal desorption and a numerical method for TDS spectrum simulation, where only integration of a nonlinear system of low order (compared with, e.g., the method of lines) ordinary differential equations (ODE) is required. This work is supported by the Russian Foundation for Basic Research (project 15-01-00744).

  8. Thermal and structural studies about the solidification process of grey cast irons; Estudio termico y estructural del proceso de solidificacion de funciones de hierro con grafito laminar

    Energy Technology Data Exchange (ETDEWEB)

    Larranaga, P.; Sertucha, J.

    2010-07-01

    The grey iron casting manufacture is an industrial process extendly used today. Therefore, the study of the solidification features obtained from this iron and the factors that have influence on such transition becomes a powerful tool in order to support the technological development of this type of material. In the present work, three inoculated alloys with different chemical compositions (hypo eutectic, eutectic and hyper eutectic) have been selected so as to comparatively analyse the structural characteristics of the irons during the liquid-solid transformation. The behaviour of the samples has been controlled recording the cooling curves and then they have been quenched in order to study the structural characteristics at different stages of the solidification. The selected alloys show different solidification features as a function of the chemical composition and the corresponding nucleation potential. The obtained results have been discussed in terms of a comparative analysis, establishing a solidification model that explains the industrial behaviour of the alloys. (Author)

  9. National grey literature cooperation model

    OpenAIRE

    Pejšová, Petra; Vyčítalová, Hana

    2015-01-01

    The National Library of Technology (NTK) has a long tradition of collecting grey literature on the national level. NTK became SIGLE system partner in the 1980s and from 2008 it has been the coordinator of the National Repository of Grey Literature (NRGL). NTK has created a grey literature partnership network in the Czech Republic. Over 130 institutions dedicated to research, science, education, culture etc. participate in this network and provide grey literature to the NRGL. NTK manages coope...

  10. mathematical model of thermal explosion, the dual variational formulation of nonlinear problem, alternative functional

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    Full Text Available A temperature state of the solid body may depend both on the conditions of heat exchange with external environment surrounding its surface and on the energy release within the body volume, caused, for example, by the processes in nuclear reactor elements or exothermic chemical reactions, absorption of penetrating radiation energy or transformation of a part of the electrical power into heat with flowing electric current (so-called Joule heat.If with growing temperature the intensity of bulk power density increases, a limited steady temperature state can emerge at which heat extracted to the body surface and released within its volume reaches maximum. Thus, small increments of temperature lead to an increase of heat release, which can not be extracted to the body surface by conduction without further temperature increase. As a result, the steady temperature distribution in the body becomes impossible that determines the state of the thermal explosion, so named due to the fact that in this case the appropriate mathematical model predicts an unlimited temperature increase.A lot of published papers and monographs concerning the study of the combustion and explosion processes in a stationary medium analyse the thermal explosion state. The most famous papers consider a mathematical model to describe a temperature distribution in the case when heat release is because of exothermic chemical reactions the rate of which increases with temperature growth. The dependence of the chemical reaction rate on temperature is usually described by the exponential Arrhenius law, which makes it necessary to consider an essentially nonlinear mathematical model containing differential equation, which includes the term, nonlinearly rising with increasing temperature. Even with simplifying assumptions, this model allows an exact closed form solution only in the case of one-dimensional temperature distributions in the two areas of the canonical form: in the plate, infinite

  11. Detection of grey seal

    NARCIS (Netherlands)

    van Bleijswijk, J.; Begeman, L.; Witte, H.J.; IJsseldijk, L.L.; Brasseur, S.M.J.M.; Gröne, A.; Leopold, M.F.

    2014-01-01

    DNA was analysed from external wounds on 3 dead harbour porpoises Phocoena phocoena that were stranded in the Netherlands. Puncture wounds as well as the edges of large open wounds were sampled with sterile cotton swabs. With specific primers that target the mtDNA control region of grey seal Halicho

  12. Detection of grey seal

    NARCIS (Netherlands)

    van Bleijswijk, J.; Begeman, L.; Witte, H.J.; IJsseldijk, L.L.; Brasseur, S.M.J.M.; Gröne, A.; Leopold, M.F.

    2014-01-01

    DNA was analysed from external wounds on 3 dead harbour porpoises Phocoena phocoena that were stranded in the Netherlands. Puncture wounds as well as the edges of large open wounds were sampled with sterile cotton swabs. With specific primers that target the mtDNA control region of grey seal

  13. Grey swan tropical cyclones

    Science.gov (United States)

    Lin, Ning; Emanuel, Kerry

    2016-01-01

    We define `grey swan’ tropical cyclones as high-impact storms that would not be predicted based on history but may be foreseeable using physical knowledge together with historical data. Here we apply a climatological-hydrodynamic method to estimate grey swan tropical cyclone storm surge threat for three highly vulnerable coastal regions. We identify a potentially large risk in the Persian Gulf, where tropical cyclones have never been recorded, and larger-than-expected threats in Cairns, Australia, and Tampa, Florida. Grey swan tropical cyclones striking Tampa, Cairns and Dubai can generate storm surges of about 6 m, 5.7 m and 4 m, respectively, with estimated annual exceedance probabilities of about 1/10,000. With climate change, these probabilities can increase significantly over the twenty-first century (to 1/3,100-1/1,100 in the middle and 1/2,500-1/700 towards the end of the century for Tampa). Worse grey swan tropical cyclones, inducing surges exceeding 11 m in Tampa and 7 m in Dubai, are also revealed with non-negligible probabilities, especially towards the end of the century.

  14. Large thermally induced nonlinear refraction of gold nanoparticles stabilized by cyclohexanone

    Energy Technology Data Exchange (ETDEWEB)

    Sarkhosh, Leila; Aleali, Hoda; Karimzadeh, Rouhollah; Mansour, Nastaran [Physics Department, Shahid Beheshti University, Evin 19839, Tehran (Iran, Islamic Republic of)

    2010-10-15

    Stabilized gold nanoparticle (AuNP) colloids have been fabricated by nanosecond pulsed laser ablation of a pure gold plate in cyclohexanone. The AuNPs colloid exhibits a UV-Vis absorption spectrum with a surface plasmon absorption peak at about 540 nm. Scanning electron microscopy has shown the formation of spherical AuNPs with average size about 53 nm. The shift of 24 cm{sup -1} is observed in the carbonyl band of the colloid using FTIR spectroscopy. This shift indicates that the monomer carbonyl group of cyclohexanone interacts with the surface of the AuNPs and leads to stabilizing the colloid. A large nonlinear refractive index of -2.92 x 10{sup -7} cm{sup 2}/W is measured using the Z-scan technique under continuous wave laser irradiation at 532 nm. Our results show that the large induced nonlinear refraction is attributed to the surface plasmon resonance (SPR) enhancement effect of AuNPs, high thermo-optic coefficient and low thermal conductivity of cyclohexanone. Observation of far-field diffraction ring patterns confirm a thermally induced negative lens effect and spatial self-phase modulation in the laser beam as it traverses the colloids. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  15. First integrals and analytical solutions of the nonlinear fin problem with temperature-dependent thermal conductivity and heat transfer coefficient

    Indian Academy of Sciences (India)

    EMRULLAH YA¸SAR; YAKUP YILDIRIM; ILKER BURAK GIRESUNLU

    2016-08-01

    Fin materials can be observed in a variety of engineering applications. They are used to ease the dissipation of heat from a heated wall to the surrounding environment. In this work, we consider a nonlinear fin problem with temperature-dependent thermal conductivity and heat transfer coefficient. The equation(s) under study are highly nonlinear. Both the thermal conductivity and the heat transfer coefficient are given as arbitrary functions of temperature. Firstly, we consider the Lie group analysis for different cases of thermal conductivity and the heat transfer coefficients. These classifications are obtained from the Lie group analysis. Then, the first integrals of the nonlinear straight fin problem are constructed by three methods, namely, Noether’s classical method, partial Noether approach and Ibragimov’s nonlocal conservation method. Some exact analytical solutions are also constructed. The obtained result is also compared with the result obtained by other methods.

  16. NONLINEAR J-E CHARACTERISTICS IN THE ELECTRIC-THERMAL EQUILIBRIUM STATE FOR HIGH DENSITY POLYETHYLENE CONDUCTIVE COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Qiang Zheng; Yi-hu Song; Xiao-su Yi

    2001-01-01

    The nonlinear J-E characteristics under self-heating equilibrium for conductive composites based on high density polyethylene were studied. The results show that there are identical conduction mechanisms under self-heating equilibrium for the composites with various initial resistivities determined by filler content or ambient temperature. The nonlinear conduction behavior was involved in the limited microstructure transformations of the conducting network induced by electrical field applied and the corresponding self-heating effect. A reversible thermal fuse (RTF) model was suggested to interpret the physical origin of the nonlinear J-E characteristics.

  17. NONLINEAR BUCKLING BEHAVIOR OF DAMAGED COMPOSITE SANDWICH PLATES CONSIDERING THE EFFECT OF TEMPERATURE-DEPENDENT THERMAL AND MECHANICAL PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Bai Ruixiang; Chen Haoran

    2001-01-01

    On the basis of the first-order shear deformation plate theory and the zig-zag deformation assumption, an incremental finite element formulation for nonlinear buckling analysis of the composite sandwich plate is deduced and the temperature-dependent thermal and mechanical properties of composite is considered. A finite element method for thermal or thermo-mechanical coupling nonlinear buckling analysis of the composite sandwich plate with an interfacial crack damage between face and core is also developed. Numerical results and discussions concerning some typical examples show that the effects of the variation of the thermal and mechanical properties with temperature, extermal compressive loading, size of the damage zone and piy angle of the faces on the thermal buckling behavior are significant.

  18. Nonlinear thermal convection in a layer of nanofluid under G-jitter and internal heating effects

    Directory of Open Access Journals (Sweden)

    Bhadauria B. S.

    2014-01-01

    Full Text Available This paper deals with a mathematical model of controlling heat transfer in nanofluids. The time-periodic vertical vibrations of the system are considered to effect an external control of heat transport along with internal heating effects. A weakly non-linear stability analysis is based on the five-mode Lorenz model using which the Nusselt number is obtained as a function of the thermal Rayleigh number, nano-particle concentration based Rayleigh number, Prandtl number, Lewis number, modified diffusivity ratio, amplitude and frequency of modulation. It is shown that modulation can be effectively used to control convection and thereby heat transport. Further, it is found that the effect of internal Rayleigh number is to enhance the heat and nano-particles transport.

  19. Relaxation behavior and nonlinear properties of thermally stable polymers based on glycidyl derivatives of quercetin

    Science.gov (United States)

    Mishurov, Dmytro; Voronkin, Andrii; Roshal, Alexander; Brovko, Oleksandr

    2016-07-01

    Cross-linked polymers on the basis of di-, tri and tetraglycidyl ethers of quercetin (3,3‧,4‧,5,7-pentahydroxyflavone) were synthesized, and then, poled in electrical field of corona discharge. Investigations of structural, thermal and optical parameters of the polymer films were carried out. It was found that the polymers obtained from di- and triglycidyl quercetin ethers had high values of macroscopic quadratic susceptibilities and substantial stability of nonlinear optical (NLO) properties after the poling. Tetraglycidyl ether of quercetin forms the polymer of lower quadratic susceptibility, which demonstrates noticeable relaxation process resulting in decrease of the NLO effect. It is supposed that the difference of the NLO properties is due to peculiarities of physical network of the polymers, namely to the ratio between numbers of hydrogen bonds formed by hydroxyl groups of chromophore fragments and by the ones of interfragmental parts of the polymeric chains.

  20. Ranking grey numbers based on dominance grey degrees

    Institute of Scientific and Technical Information of China (English)

    Yong Liu; Jeffrey Forrest; Naiming Xie

    2014-01-01

    With respect to the decision making problems where a lot of fuzzy and grey information always exists in the real-life deci-sion making information system, it is difficult for such uncertainty methods as fuzzy mathematics, probability, and interval numbers to deal with. To this end, based on the thought and method of grey numbers, grey degrees and interval numbers, the concept of dominance grey degree is defined. And then a method of rank-ing interval grey numbers based on the dominance grey degree is proposed. After discussing the relevant properties, the paper final y uses an example to demonstrate the effectiveness and ap-plicability of the model. The result shows that the proposed model can more accurately describe uncertainty decision making prob-lems, and realize the total ordering process for multiple-attribute decision-making problems.

  1. Structural, thermal, optical and nonlinear optical properties of ethylenediaminium picrate single crystals

    Science.gov (United States)

    Indumathi, C.; T. C., Sabari Girisun; Anitha, K.; Alfred Cecil Raj, S.

    2017-07-01

    A new organic optical limiting material, ethylenediaminium picrate (EDAPA) was synthesized through acid base reaction and grown as single crystals by solvent evaporation method. Single crystal XRD analysis showed that EDAPA crystallizes in orthorhombic system with Cmca as space group. The formation of charge transfer complex during the reaction of ethylenediamine and picric acid was strongly evident through the recorded Fourier Transform Infra Red (FTIR), Raman and Nuclear Magnetic Resonance (NMR) spectrum. Thermal (TG-DTA and DSC) curves indicated that the material possesses high thermal stability with decomposition temperature at 243 °C. Optical (UV-Visible-NIR) analysis showed that the grown crystal was found to be transparent in the entire visible and NIR region. Z-scan studies with intense short pulse (532 nm, 5 ns, 100 μJ) excitations, revealed that EDAPA exhibited two photon absorption behaviour and the nonlinear absorption coefficient was found to be two orders of magnitude higher than some of the known optical limiter like Cu nano glasses. EDAPA exhibited a strong optical limiting action with low limiting threshold which make them a potential candidate for eye and photosensitive component protection against intense short pulse lasers.

  2. Thermal fluctuations and effective bending stiffness of elastic thin sheets and graphene: A nonlinear analysis

    Science.gov (United States)

    Ahmadpoor, Fatemeh; Wang, Peng; Huang, Rui; Sharma, Pradeep

    2017-10-01

    The study of statistical mechanics of thermal fluctuations of graphene-the prototypical two-dimensional material-is rendered rather complicated due to the necessity of accounting for geometric deformation nonlinearity. Unlike fluid membranes such as lipid bilayers, coupling of stretching and flexural modes in solid membranes like graphene leads to a highly anharmonic elastic Hamiltonian. Existing treatments draw heavily on analogies in the high-energy physics literature and are hard to extend or modify in the typical contexts that permeate materials, mechanics and some of the condensed matter physics literature. In this study, using a variational perturbation method, we present a ;mechanics-oriented; treatment of the thermal fluctuations of elastic sheets such as graphene and evaluate their effect on the effective bending stiffness at finite temperatures. In particular, we explore the size, pre-strain and temperature dependency of the out-of-plane fluctuations, and demonstrate how an elastic sheet becomes effectively stiffer at larger sizes. Our derivations provide a transparent approach that can be extended to include multi-field couplings and anisotropy for other 2D materials. To reconcile our analytical results with atomistic considerations, we also perform molecular dynamics simulations on graphene and contrast the obtained results and physical insights with those in the literature.

  3. Analysis of Radiative Radial Fin with Temperature-Dependent Thermal Conductivity Using Nonlinear Differential Transformation Methods

    Directory of Open Access Journals (Sweden)

    Mohsen Torabi

    2013-01-01

    Full Text Available Radiative radial fin with temperature-dependent thermal conductivity is analyzed. The calculations are carried out by using differential transformation method (DTM, which is a seminumerical-analytical solution technique that can be applied to various types of differential equations, as well as the Boubaker polynomials expansion scheme (BPES. By using DTM, the nonlinear constrained governing equations are reduced to recurrence relations and related boundary conditions are transformed into a set of algebraic equations. The principle of differential transformation is briefly introduced and then applied to the aforementioned equations. Solutions are subsequently obtained by a process of inverse transformation. The current results are then compared with previously obtained results using variational iteration method (VIM, Adomian decomposition method (ADM, homotopy analysis method (HAM, and numerical solution (NS in order to verify the accuracy of the proposed method. The findings reveal that both BPES and DTM can achieve suitable results in predicting the solution of such problems. After these verifications, we analyze fin efficiency and the effects of some physically applicable parameters in this problem such as radiation-conduction fin parameter, radiation sink temperature, heat generation, and thermal conductivity parameters.

  4. Thermal effects on nonlinear vibration of a carbon nanotube-based mass sensor using finite element analysis

    Science.gov (United States)

    Kang, Dong-Keun; Kim, Chang-Wan; Yang, Hyun-Ik

    2017-01-01

    In the present study we carried out a dynamic analysis of a CNT-based mass sensor by using a finite element method (FEM)-based nonlinear analysis model of the CNT resonator to elucidate the combined effects of thermal effects and nonlinear oscillation behavior upon the overall mass detection sensitivity. Mass sensors using carbon nanotube (CNT) resonators provide very high sensing performance. Because CNT-based resonators can have high aspect ratios, they can easily exhibit nonlinear oscillation behavior due to large displacements. Also, CNT-based devices may experience high temperatures during their manufacture and operation. These geometrical nonlinearities and temperature changes affect the sensing performance of CNT-based mass sensors. However, it is very hard to find previous literature addressing the detection sensitivity of CNT-based mass sensors including considerations of both these nonlinear behaviors and thermal effects. We modeled the nonlinear equation of motion by using the von Karman nonlinear strain-displacement relation, taking into account the additional axial force associated with the thermal effect. The FEM was employed to solve the nonlinear equation of motion because it can effortlessly handle the more complex geometries and boundary conditions. A doubly clamped CNT resonator actuated by distributed electrostatic force was the configuration subjected to the numerical experiments. Thermal effects upon the fundamental resonance behavior and the shift of resonance frequency due to attached mass, i.e., the mass detection sensitivity, were examined in environments of both high and low (or room) temperature. The fundamental resonance frequency increased with decreasing temperature in the high temperature environment, and increased with increasing temperature in the low temperature environment. The magnitude of the shift in resonance frequency caused by an attached mass represents the sensing performance of a mass sensor, i.e., its mass detection

  5. Evaluating clay mineralogy as a thermal maturity indicator for Upper Devonian black and grey shales and siltstones within the Ohio Appalachian Basin

    Science.gov (United States)

    Strong, Zachary M.

    The clay mineralogy of the Upper Devonian age Chagrin and Huron Shale Members of the Ohio Shale was analyzed over in eastern Ohio to evaluate the usefulness of comparing the ratio between illite and smectite within mixed layer clay minerals to estimate thermal maturity. The process by which smectite diagenetically converts over time to illite via burial diagenesis has been rigorously studied in the past because of its relationship with thermal maturity. While simply understanding the thermal maturity of target formations is important, studies of illitization with depth can also give insight to hydrocarbon generation windows. This relationship allows for a prediction to be made on the stages of hydrocarbon generation that have occurred in a target formation based on the ratio of illite to smectite and the Reichweite ordering within the mixed layer clay. Eighty-four samples were taken across an 8 county study area from the top and center of the Chagrin Shale Member and the center of the Huron Shale Member. X-ray diffraction (XRD) analysis was carried out on both bulk powder and clay fraction powder samples to gain an understanding of both clay and nonclay minerals present in each sample. Clay fraction samples were analyzed in the air-dried state, after treatment with ethylene glycol, and after heating to 550° for 30 minutes, to identify all clays present. The Kubler index, the measure of full width at half maximum (FWHM), of the 10 A illite peak in the air-dried state was also recorded using XRD analysis for each sample. This was done to help identify the presence of mixed layer clays containing only a small expandable component. Environmental Scanning Electron Microscope (ESEM) imaging was carried out to evaluate clay authigenesis with depth, and total organic carbon (TO C) was measured via elemental combustion in a CHN analyzer. XRD analysis revealed that illite is the dominant clay mineral in all of the samples analyzed in the study and, on average, illite

  6. Nonlinear thermal and moisture dynamics of high Arctic wetland polygons following permafrost disturbance

    Directory of Open Access Journals (Sweden)

    E. Godin

    2015-07-01

    Full Text Available Low-centre polygonal terrain developing within gentle sloping surfaces and lowlands in the high Arctic have a potential to retain snowmelt water in their bowl-shaped centre and as such are considered high latitude wetlands. Such wetlands in the continuous permafrost regions have an important ecological role in an otherwise generally arid region. In the valley of the glacier C-79 on Bylot Island (Nunavut, Canada, thermal erosion gullies are rapidly eroding the permafrost along ice wedges affecting the integrity of the polygons by breaching and collapsing the surrounding rims. While intact polygons were characterized by a relative homogeneity (topography, snow cover, maximum active layer thaw depth, ground moisture content, vegetation cover, eroded polygons had a non-linear response for the same elements following their perturbation. The heterogeneous nature of disturbed terrains impacts active layer thickness, ground ice aggradation in the upper portion of permafrost, soil moisture and vegetation dynamics, carbon storage and terrestrial green-house gas emissions.

  7. Drapeaux Gris (Grey Flags

    Directory of Open Access Journals (Sweden)

    Mathilde Arrivé

    2007-07-01

    Full Text Available Today it is images, a thickening web of images, amounting to a magic circle through which the citizens of this age have passed, never to return. What a time you chose to be born ! (... The question, then, is how to paint one’s subjectivity in the codes of culture ?Grey Flags, texte de Seth Price, (Communiqué de presse et titre de l’expositionJeux de pistes pour un art « sans drapeau »Si dans les années soixante les Flags de Jasper Johns problématisaient les catégories artistiques en détourn...

  8. Non-linear thermal engineering, chaotic advection and mixing; Thermique non-lineaire, melange et advection chaotique

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This conference day was jointly organized by the `university group of thermal engineering (GUT)` and the French association of thermal engineers. This book of proceedings contains 7 papers entitled: `energy spectra of a passive scalar undergoing advection by a chaotic flow`; `analysis of chaotic behaviours: from topological characterization to modeling`; `temperature homogeneity by Lagrangian chaos in a direct current flow heat exchanger: numerical approach`; ` thermal instabilities in a mixed convection phenomenon: nonlinear dynamics`; `experimental characterization study of the 3-D Lagrangian chaos by thermal analogy`; `influence of coherent structures on the mixing of a passive scalar`; `evaluation of the performance index of a chaotic advection effect heat exchanger for a wide range of Reynolds numbers`. (J.S.)

  9. Optical nonlinearity of Rydberg electromagnetically induced transparency in thermal vapor using the optical-heterodyne-detection technique

    Science.gov (United States)

    Bhowmick, Arup; Sahoo, Sushree S.; Mohapatra, Ashok K.

    2016-08-01

    We discuss the optical-heterodyne-detection technique to study the absorption and dispersion of a probe beam propagating through a medium with a narrow resonance. The technique has been demonstrated for Rydberg electromagnetically induced transparency in rubidium thermal vapor and the optical nonlinearity of a probe beam with variable intensity has been studied. A quantitative comparison of the experimental result with a suitable theoretical model is presented. The limitations and the working regime of the technique are discussed.

  10. On the Forms of Nonlinear Propagation of High-Frequency Perturbation in a Thermal Relaxing Gas-Liquid mixture

    Directory of Open Access Journals (Sweden)

    Ohanyan G.G.

    2010-09-01

    Full Text Available The quasi-adiabatic and quasi-isotherm regimes of propagation of high-frequency perturbation are considered in a thermal relaxing gas–fluid mixture. The simplified non-linear equations are obtained. It is shown that in the absence of heat transfer and under the quasi-adiabatic regime the form of propagation is soliton, or the shock wave in quasi-isotherm regime.

  11. On the Forms of Nonlinear Propagation of High-Frequency Perturbation in a Thermal Relaxing Gas-Liquid mixture

    OpenAIRE

    Ohanyan G.G.

    2010-01-01

    The quasi-adiabatic and quasi-isotherm regimes of propagation of high-frequency perturbation are considered in a thermal relaxing gas–fluid mixture. The simplified non-linear equations are obtained. It is shown that in the absence of heat transfer and under the quasi-adiabatic regime the form of propagation is soliton, or the shock wave in quasi-isotherm regime.

  12. Grey Literature in the Czech Republic

    OpenAIRE

    Pejšová, Petra; Pfeiferová, Martina

    2008-01-01

    Contribution summarizes activities concerning grey literature in the Czech Republic. Contribution describes relationships between systems/projects collecting grey literature and position grey literature in the Czech Digital Library. Contribution is especially focused on a project “The Digital Library for Grey Literature –Functional Model and Pilot Implementation”, which solves the State Technical Library.

  13. Research on evaluations of several grey relational models adapt to grey relational axioms

    Institute of Scientific and Technical Information of China (English)

    Xie Naiming; Liu Sifeng

    2009-01-01

    Grey relational analysis is an important part of the grey systems theory, and it is the basis of the grey clustering analysis, grey decision-making and grey controlling. To research whether grey relational models satisfy the four grey relational theorems, several kinds of grey relational models are commented. Some problems including the properties of normality, pair symmetry and wholeness are discussed. The phenomenon that the lower value of almost each grey relational model is not equal to zero is proved. The contradiction problems between the properties of wholeness and pair symmetry are verified. Finally, several propositions are constructed to explain the above problems.

  14. Determination of refraction nonlinear index, for effect thermal, of solutions with nanoparticles of gold

    Science.gov (United States)

    Olivares-Vargas, A.; Trejo-Durán, M.; Alvarado-Méndez, E.; Cornejo-Monroy, D.; Mata-Chávez, R. I.; Estudillo-Ayala, J. M.; Castaño-Meneses, V.

    2013-09-01

    Research of nonlinear optical properties of materials for manufacturing opto-electronic devices, had a great growth in the last years. The solutions with nanoparticle metals present nonlinear optical properties. In this work we present the results of characterizing, analyzing and determining the magnitude and sign of the nonlinear refractive index, using the z-scan technique in solutions with nanoparticles of gold, lipoic acid and sodium chloride. We used a continuous Argon laser at 514 nm with variable power, an 18 cms lens, and a chopper. We determined the nonlinear refractive index in the order of 10-9. These materials have potential applications mainly as optical limiters.

  15. The demonstration of nonlinear analytic model for the strain field induced by thermal copper filled TSVs (through silicon via

    Directory of Open Access Journals (Sweden)

    M. H. Liao

    2013-08-01

    Full Text Available The thermo-elastic strain is induced by through silicon vias (TSV due to the difference of thermal expansion coefficients between the copper (∼18 ppm/ °C and silicon (∼2.8 ppm/ °C when the structure is exposed to a thermal ramp budget in the three dimensional integrated circuit (3DIC process. These thermal expansion stresses are high enough to introduce the delamination on the interfaces between the copper, silicon, and isolated dielectric. A compact analytic model for the strain field induced by different layouts of thermal copper filled TSVs with the linear superposition principle is found to have large errors due to the strong stress interaction between TSVs. In this work, a nonlinear stress analytic model with different TSV layouts is demonstrated by the finite element method and the analysis of the Mohr's circle. The characteristics of stress are also measured by the atomic force microscope-raman technique with nanometer level space resolution. The change of the electron mobility with the consideration of this nonlinear stress model for the strong interactions between TSVs is ∼2–6% smaller in comparison with those from the consideration of the linear stress superposition principle only.

  16. Grey literature in Australian education

    OpenAIRE

    White, Gerald (ACER); Thomas, Julian (Swinburne University); Weldon, Paul; Lawrence, Amanda (Swinburne University); Galatis, Helen (ACER); Tyndall, Jessica (Flinders University); GreyNet, Grey Literature Network Service

    2013-01-01

    The prevalence of informal publishing or grey literature in education appears to have increased as digital technologies have become main-stream, educators have become more proficient and policies have moved increasingly towards supporting its use. In addition, the take up of social networking technologies and innovative methods of digital publishing have encouraged educators to produce, distribute and share content and commentary. Grey literature may make a substantial contribution to educati...

  17. Study of Rydberg blockade mediated optical non-linearity in thermal vapor using optical heterodyne detection technique

    CERN Document Server

    Bhowmick, Arup; Mohapatra, Ashok K

    2016-01-01

    We demonstrate the phenomenon of blockade in two-photon excitations to the Rydberg state in thermal vapor. A technique based on optical heterodyne is used to measure the dispersion of a probe beam far off resonant to the D2 line of rubidium in the presence of a strong laser beam that couples to the Rydberg state via two-photon resonance. Density dependent suppression of the dispersion peak is observed while coupling to the Rydberg state with principal quantum number, n = 60. The experimental observation is explained using the phenomenon of Rydberg blockade. The blockade radius is measured to be about 2.2 {\\mu}m which is consistent with the scaling due to the Doppler width of 2-photon resonance in thermal vapor. Our result promises the realization of single photon source and strong single photon non-linearity based on Rydberg blockade in thermal vapor.

  18. Real-space post-processing correction of thermal drift and piezoelectric actuator nonlinearities in scanning tunneling microscope images

    CERN Document Server

    Yothers, Mitchell P; Bumm, Lloyd A

    2016-01-01

    We have developed a real-space method to correct distortion due to thermal drift and piezoelectric actuator nonlinearities on scanning tunneling microscope images using Matlab. The method uses the known structures typically present in high-resolution atomic and molecularly-resolved images as an internal standard. Each image feature (atom or molecule) is first identified in the image. The locations of each feature's nearest neighbors (NNs) are used to measure the local distortion at that location. The local distortion map across the image is simultaneously fit to our distortion model, which includes thermal drift in addition to piezoelectric actuator hysteresis and creep. The image coordinates of the features and image pixels are corrected using an inverse transform from the distortion model. We call this technique the thermal-drift, hysteresis, and creep transform (DHCT). Performing the correction in real space allows defects, domain boundaries, and step edges to be excluded with a spatial mask. Additional re...

  19. A parallel multi-domain solution methodology applied to nonlinear thermal transport problems in nuclear fuel pins

    Science.gov (United States)

    Philip, Bobby; Berrill, Mark A.; Allu, Srikanth; Hamilton, Steven P.; Sampath, Rahul S.; Clarno, Kevin T.; Dilts, Gary A.

    2015-04-01

    This paper describes an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors is described. Details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstrating the achieved efficiency of the algorithm are presented. Furthermore, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods. Finally, we demonstrate the power of the coupling methodology by considering problems with couplings between surface and volume physics and coupling of nonlinear thermal transport in fuel rods to an external radiation transport code.

  20. A new branch solution for the nonlinear fin problem with temperature-dependent thermal conductivity and heat transfer coefficient

    Science.gov (United States)

    Shivanian, Elyas; Hosseini Ghoncheh, S. J.

    2017-02-01

    In this paper, the nonlinear fin problem with temperature-dependent thermal conductivity and heat transfer coefficient is revisited. In this problem, it has been assumed that the heat transfer coefficient is expressed in a power-law form and the thermal conductivity is a linear function of temperature. A method based on the traditional shooting method and the homotopy analysis method is applied, the so-called shooting homotopy analysis method (SHHAM), to the governing nonlinear differential equation. In this technique, more high-order approximate solutions are computable and multiple solutions are easily searched and discovered due to being free of the symbolic variable. It is found that the solution might be empty, unique or dual depending on the values of the parameters of the model. Furthermore, corresponding fin efficiencies with high accuracy are computed. As a consequence, a new branch solution for this nonlinear problem by a new proposed method, based on the traditional shooting method and the homotopy analysis method, is obtained.

  1. Thermal and Mechanical Properties of a Complex Nonlinear Optical Material: Cadmium Mercury Thiocyanate Crystal

    Institute of Scientific and Technical Information of China (English)

    YUAN Duo-Rong; XU Dong; ZHANG Guang-Hui; LIU Ming-Guo; GUO Shi-Yi; MENG Fan-Qing; LU Meng-Kai; FANG Qi; JIANG Min-Hua

    2000-01-01

    Institute of Crystal Materials and State Key Laboratory of Crystal Materials, Shandong University, Ji'nan 250100 (Received 18 March 2000) The data of the thermal expansion and specific heat of cadmium mercury thiocyanate crystal have been obtained. The specific heat is 0.7588J/g℃ at room temperature. The thermal expansion occurs in the direction parallel to the c-axis, and the thermal contraction occurs in the direction parallel to the a-axis. The thermal expansion is the same as the thermal contraction at 353 K. The relationship between thermal properties and crystal structure is discussed.

  2. MHD Natural Convection Flow of Casson Nanofluid over Nonlinearly Stretching Sheet Through Porous Medium with Chemical Reaction and Thermal Radiation

    Science.gov (United States)

    Ullah, Imran; Khan, Ilyas; Shafie, Sharidan

    2016-11-01

    In the present work, the effects of chemical reaction on hydromagnetic natural convection flow of Casson nanofluid induced due to nonlinearly stretching sheet immersed in a porous medium under the influence of thermal radiation and convective boundary condition are performed numerically. Moreover, the effects of velocity slip at stretching sheet wall are also examined in this study. The highly nonlinear-coupled governing equations are converted to nonlinear ordinary differential equations via similarity transformations. The transformed governing equations are then solved numerically using the Keller box method and graphical results for velocity, temperature, and nanoparticle concentration as well as wall shear stress, heat, and mass transfer rate are achieved through MATLAB software. Numerical results for the wall shear stress and heat transfer rate are presented in tabular form and compared with previously published work. Comparison reveals that the results are in good agreement. Findings of this work demonstrate that Casson fluids are better to control the temperature and nanoparticle concentration as compared to Newtonian fluid when the sheet is stretched in a nonlinear way. Also, the presence of suspended nanoparticles effectively promotes the heat transfer mechanism in the base fluid.

  3. MHD Natural Convection Flow of Casson Nanofluid over Nonlinearly Stretching Sheet Through Porous Medium with Chemical Reaction and Thermal Radiation.

    Science.gov (United States)

    Ullah, Imran; Khan, Ilyas; Shafie, Sharidan

    2016-12-01

    In the present work, the effects of chemical reaction on hydromagnetic natural convection flow of Casson nanofluid induced due to nonlinearly stretching sheet immersed in a porous medium under the influence of thermal radiation and convective boundary condition are performed numerically. Moreover, the effects of velocity slip at stretching sheet wall are also examined in this study. The highly nonlinear-coupled governing equations are converted to nonlinear ordinary differential equations via similarity transformations. The transformed governing equations are then solved numerically using the Keller box method and graphical results for velocity, temperature, and nanoparticle concentration as well as wall shear stress, heat, and mass transfer rate are achieved through MATLAB software. Numerical results for the wall shear stress and heat transfer rate are presented in tabular form and compared with previously published work. Comparison reveals that the results are in good agreement. Findings of this work demonstrate that Casson fluids are better to control the temperature and nanoparticle concentration as compared to Newtonian fluid when the sheet is stretched in a nonlinear way. Also, the presence of suspended nanoparticles effectively promotes the heat transfer mechanism in the base fluid.

  4. Breakdown of nonlinear elasticity in stress-controlled thermal amorphous solids

    Science.gov (United States)

    Dailidonis, Vladimir; Ilyin, Valery; Procaccia, Itamar; Shor, Carmel A. B. Z.

    2017-03-01

    In recent work it was clarified that amorphous solids under strain control do not possess nonlinear elastic theory in the sense that the shear modulus exists but nonlinear moduli exhibit sample-to-sample fluctuations that grow without bound with the system size. More relevant, however, for experiments are the conditions of stress control. In the present Rapid Communication we show that also under stress control the shear modulus exists, but higher-order moduli show unbounded sample-to-sample fluctuation. The unavoidable consequence is that the characterization of stress-strain curves in experiments should be done with a stress-dependent shear modulus rather than with nonlinear expansions.

  5. Thermal, size and surface effects on the nonlinear pull-in of small-scale piezoelectric actuators

    Science.gov (United States)

    SoltanRezaee, Masoud; Ghazavi, Mohammad-Reza

    2017-09-01

    Electrostatically actuated miniature wires/tubes have many operational applications in the high-tech industries. In this research, the nonlinear pull-in instability of piezoelectric thermal small-scale switches subjected to Coulomb and dissipative forces is analyzed using strain gradient and modified couple stress theories. The discretized governing equation is solved numerically by means of the step-by-step linearization method. The correctness of the formulated model and solution procedure is validated through comparison with experimental and several theoretical results. Herein, the length-scale, surface energy, van der Waals attraction and nonlinear curvature are considered in the present comprehensive model and the thermo-electro-mechanical behavior of cantilever piezo-beams are discussed in detail. It is found that the piezoelectric actuation can be used as a design parameter to control the pull-in phenomenon. The obtained results are applicable in stability analysis, practical design and control of actuated miniature intelligent devices.

  6. A Parallel Multi-Domain Solution Methodology Applied to Nonlinear Thermal Transport Problems in Nuclear Fuel Pins

    CERN Document Server

    Philip, Bobby; Allu, Srikanth; Hamilton, Steven P; Sampath, Rahul S; Clarno, Kevin T; Dilts, Gary A

    2014-01-01

    This paper describes an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors is described. Details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstrating the achieved efficiency of the algorithm are presented. Furthermore, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods...

  7. Interference and non-linear properties of four-wave mixing resonances in thermal vapor: analytical results and experimental verification

    CERN Document Server

    Parniak, Michał

    2014-01-01

    We develop a model to calculate non-linear polarization in a non-degenerrate four-wave mixing in diamond configuration which includes the effects of hyperfine structure and Doppler broadening. We verify it against the experiment with $5^{2}S_{1/2}$, $5^{2}P_{3/2}$, $5^{2}D_{3/2}$ and $5^{2}P_{1/2}$ levels of rubidium 85. Uncomplicated algebra enables us to express the non-linear susceptibility of a thermal ensemble in low intensity regime in terms of Voight-like profiles and conforms precisely with the experiment. The agreement is also satisfactory at high intensity and the analytical model correctly predicts the position and shape of resonances. Our intelligible results elucidate the physics of coherent interaction of light with atoms involving higher excited levels in vapors at room temperature, which is used in an increasing range of applications.

  8. An experimentally verified model for thermal microactuators including nonlinear material properties, vacuum, and intra-device heat conduction

    Science.gov (United States)

    Colbert, Keegan; Naraghi, Mohammad; Boyd, James G.

    2017-02-01

    This paper presents a model and computational method to predict the steady-state performance of thermal flexure microactuators at high input powers and various levels of partial vacuum. The model accounts for nonlinear temperature dependence of material properties, heat loss due to radiation, and intra-device heat transfer by conduction across an air gap. The model is validated by comparing the model predictions with the experimentally measured voltage, current, and displacement at standard conditions, prior to adjusting for partial vacuum. In order to understand the effect of nonlinearities on model reliability, the predictions of six additional hypothetical models are considered where (1) intra-device heat transfer is neglected, (2) radiation is neglected, (3) the thermal conductivity of silicon is assumed to be temperature-independent, (4) the thermal conductivity of air is assumed to be temperature-independent, (5) the electrical resistivity of silicon is assumed to be linear in temperature, and (6) the thermal expansion coefficient of silicon is assumed to be temperature-independent. All factors except radiation were shown to have a significant influence on the device performance especially at high input powers. The experimentally validated full model is then employed to predict the effect of reduced air pressure on the displacement and heat transfer properties of the actuator. This aspect of the study targets applications of thermal actuators in controlled environments such as space applications, actuators used for in situ micropositioning and tensile testing inside electron microscopy chambers, or actuators incorporated into the design of MEMS resonators. It was demonstrated that the maximum actuator displacement is not a linear function of reduced pressure and that it reaches a maximum at a certain partial vacuum level.

  9. A novel kernel regularized nonhomogeneous grey model and its applications

    Science.gov (United States)

    Ma, Xin; Hu, Yi-sheng; Liu, Zhi-bin

    2017-07-01

    The nonhomogeneous grey model (NGM) is a novel tool for time series forecasting, which has attracted considerable interest of research. However, the existing nonhomogeneous grey models may be inefficient to predict the complex nonlinear time series sometimes due to the linearity of the differential or difference equations based on which these models are developed. In order to enhance the accuracy and applicability of the NGM model, the kernel method in the statistical learning theory has been utilized to build a novel kernel regularized nonhomogeneous grey model, which is abbreviated as the KRNGM model. The KRNGM model is represented by a differential equation which contains a nonlinear function of t. By constructing the regularized problem and using the kernel function which satisfies the Mercer's condition, the parameters estimation of KRNGM model only involves in solving a set of linear equations, and the nonlinear function in the KRNGM model can be expressed as a linear combination of the Lagrangian multipliers and the selected kernel function, and then the KRNGM model can be solved numerically. Two case studies of petroleum production forecasting are carried to illustrate the effectiveness of the KRNGM model, comparing to the existing nonhomogeneous models. The results show that the KRNGM model outperforms the existing NGM, ONGM, NDGM model significantly.

  10. Grey Relational Analysis of Thermal Oxidative Water Aging Performances of TOR Rubber Asphalts%TOR橡胶沥青热氧水老化性能的灰关联分析

    Institute of Scientific and Technical Information of China (English)

    肖鹏; 蒋德安; 吴美平

    2012-01-01

    The grey relational analysis is used to study the influences of water parameters on the performances of trans-polyoctenamer reactive modifier (TOR) rubber asphalts of thermal oxidative water aging. Brinell viscosity, dynamic shear rheometer and bending beam rheometer are employed to analyse the properties of the aged TOR rubber asphalts with different water parameters. The results show that the pH value and chlorine salt content of water have influences on the properties of the aged asphalts; the greater the acidity and the higher the sodium chloride contents are, the more serious the aged degrees of the TOR rubber asphalts are,and the worse the TOR rubber asphalts' low temperature performances and abilities of dissipation about temperature stress are; the change of the pH value is the most influential factor of the aged TOR rubber asphalts' abilities of dissipation about temperature stress; the changes of the sodium chloride contents have significant effects on the low temperature anti-crack abilities, high temperature stabilities and anti-fatigue cracking performances of the asphalts.%该文将灰关联分析用于研究热氧水老化过程中,水的参数对维他连接剂(TOR)橡胶沥青性能的影响.使用布氏粘度仪、动态剪切流变仪、弯曲梁流变仪,对不同水的参数下,老化后的TOR橡胶沥青特性进行研究.结果表明:沥青老化后性能受水的pH值和氯盐质量分数影响;水的酸性越大,氯盐质量分数越高,TOR橡胶沥青老化程度越严重,热氧水老化后的TOR橡胶沥青的低温性能和对温度应力的消散能力越差;pH值的改变对老化后TOR橡胶沥青对温度应力的消散能力影响最大;氯盐质量分数变化对沥青的低温抗裂能力、高温稳定性能以及抗疲劳开裂能力有显著影响.

  11. GreyGuide Forum and Repository

    OpenAIRE

    Biagioni, Stefania; Farace, Dominic

    2014-01-01

    We present the GreyGuide: an online forum and repository of good practice in the field of grey literature. The launch of the GreyGuide Repository took place in December 2013 at the Fifteenth International Conference on Grey Literature. Since then, the acquisition of both proposed and published good practices are underway. The GreyGuide as an online forum is currently in a developmental stage and is influenced by the changes that have taken place in GreyNet's new infrastructure commencing in J...

  12. Elastic-Plastic Nonlinear Response of a Space Shuttle External Tank Stringer. Part 2; Thermal and Mechanical Loadings

    Science.gov (United States)

    Knight, Norman F., Jr.; Warren, Jerry E.; Elliott, Kenny B.; Song, Kyongchan; Raju, Ivatury S.

    2012-01-01

    Elastic-plastic, large-deflection nonlinear thermo-mechanical stress analyses are performed for the Space Shuttle external tank s intertank stringers. Detailed threedimensional finite element models are developed and used to investigate the stringer s elastic-plastic response for different thermal and mechanical loading events from assembly through flight. Assembly strains caused by initial installation on an intertank panel are accounted for in the analyses. Thermal loading due to tanking was determined to be the bounding loading event. The cryogenic shrinkage caused by tanking resulted in a rotation of the intertank chord flange towards the center of the intertank, which in turn loaded the intertank stringer feet. The analyses suggest that the strain levels near the first three fasteners remain sufficiently high that a failure may occur. The analyses also confirmed that the installation of radius blocks on the stringer feet ends results in an increase in the stringer capability.

  13. A non-grey analytical model for irradiated atmospheres. I: Derivation

    CERN Document Server

    Parmentier, Vivien

    2013-01-01

    Context. Semi-grey atmospheric models (with one opacity for the visible and one opacity for the infrared) are useful to understand the global structure of irradiated atmospheres, their dynamics and the interior structure and evolution of planets, brown dwarfs and stars. But when compared to direct numerical radiative transfer calculations for irradiated exoplanets, these models systematically overestimate the temperatures at low optical depth, independently of the opacity parameters. We wish to understand why semi-grey models fail at low optical depths, and provide a more accurate approximation to the atmospheric structure by accounting for the variable opacity in the infrared. Our analytical irradiated non-grey model is found to provide a range of temperatures that is consistent with that obtained by numerical calculations. We find that even for slightly non-grey thermal opacities the temperature structure differs significantly from previous semi-grey models. For small values of beta (expected when lines are...

  14. Grey Rod Test in HANARO Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Choo, K. N.; Kim, B. G.; Kang, Y. H. (and others)

    2008-08-15

    Westinghouse/KAERI/KNF agreed to perform an irradiation test in the HANARO reactor to obtain irradiation data on the new grey rods that will be part of an AP1000 system. As a preliminary test, two samples containing pure Ag (Reference) and Ag-In-Cd materials provided by Westinghouse Electric Company (WEC) were inserted in a KNF irradiation capsule of 07M-13N. The specimens were irradiated for 95.19days (4 cycles) in the CT test hole of the HANARO of a 30MW thermal output to have a fast neutron fluence of 1.11x10{sup 21}(n/cm{sup 2}) (E>1.0MeV). This report provides all the test conditions and data obtained during the irradiation test of the grey rods in HANARO requested by Westinghouse. The test was prepared according to the meeting minutes (June 26, 2007) and the on-going subject test was stopped midway by the request of Westinghouse.

  15. Grey matter changes in cognitively impaired Parkinson's disease patients.

    Directory of Open Access Journals (Sweden)

    Irena Rektorova

    Full Text Available BACKGROUND: Cortical changes associated with cognitive decline in Parkinson's disease (PD are not fully explored and require investigations with established diagnostic classification criteria. OBJECTIVE: We used MRI source-based morphometry to evaluate specific differences in grey matter volume patterns across 4 groups of subjects: healthy controls (HC, PD with normal cognition (PD-NC, PD with mild cognitive impairment (MCI-PD and PD with dementia (PDD. METHODS: We examined 151 consecutive subjects: 25 HC, 75 PD-NC, 29 MCI-PD, and 22 PDD at an Italian and Czech movement disorder centre. Operational diagnostic criteria were applied to classify MCI-PD and PDD. All structural MRI images were processed together in the Czech centre. The spatial independent component analysis was used to assess group differences of local grey matter volume. RESULTS: We identified two independent patterns of grey matter volume deviations: a Reductions in the hippocampus and temporal lobes; b Decreases in fronto-parietal regions and increases in the midbrain/cerebellum. Both patterns differentiated PDD from all other groups and correlated with visuospatial deficits and letter verbal fluency, respectively. Only the second pattern additionally differentiated PD-NC from HC. CONCLUSION: Grey matter changes in PDD involve areas associated with Alzheimer-like pathology while fronto-parietal abnormalities are possibly an early marker of PD cognitive decline. These findings are consistent with a non-linear cognitive progression in PD.

  16. Investigations on the electrical, thermal and optical properties of the nonlinear optical allylthiourea mercury chloride single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Sreekanth, G. [Department of Physics, St. Thomas College Pala, Kottayam 686574, Kerala (India); Chandralingam, S. [Department of Physics, Jawaharlal Nehru Technological University, Hyderabad 500085 (India); Philip, Jacob; Jayalakshmy, M.S. [Department of instrumentation, Cochin University of Science and Technology, Cochin, Kerala (India); Philip, Reji; Sridharan, Kishore [Raman research institute, Bangalore, Karnataka 560080 (India); Santhosh Kumar, R. [Department of Physics, St. George' s College Aruvithura, Kottayam 686122, Kerala (India); Joseph, Ginson P., E-mail: ginsonpj@gmail.com [Department of Physics, St. Thomas College Pala, Kottayam 686574, Kerala (India)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► The single crystals of dimension 10 × 5 × 5 mm{sup 3} of allylthiourea mercury chloride are synthesized using slow evaporation technique. ► The bandgap of allylthiourea mercury chloride crystal is found to be about 3.18 eV. ► The optical nonlinearity of the crystal sample are studied using the open aperture Z-scan technique employing a nanosecond laser at 532 nm, and three photon absorption effect has been found. ► An improved photo pyroelectric is used to find the thermal parameters of the crystal. ► The piezoelectric charge coefficient is determined. -- Abstract: Single crystals of dimension 10 × 5 × 5 mm{sup 3} of allylthiourea mercury chloride were synthesized from aqueous solution using slow evaporation technique at ambient temperature. The grown crystals are confirmed by elemental analysis. The band gap of Allylthiourea mercury chloride crystal was found to be about 3.18 eV. The optical nonlinearity of the crystal sample was studied using the open aperture Z-scan technique employing a nanosecond laser at 532 nm, and a three-photon absorption effect has been found. The electrical properties such as dielectric constant, dielectric loss and ac conductivity of the sample were carried out by Agillent E 4980 A LCR meter at different temperatures. An improved photopyroelectric technique was used to find the thermal parameters of the crystal. The piezo electric charge coefficient is also determined.

  17. Influence of Architecture, Concentration, and Thermal History on the Poling of Nonlinear Optical Chromophores in Block Copolymer Domains

    Energy Technology Data Exchange (ETDEWEB)

    Leolukman, Melvina; Paoprasert, Peerasak; Wang, Yao; Makhija, Varun; McGee, David J.; Gopalan, Padma (UW)

    2008-10-02

    Factors affecting the electric-field-induced poling of nonlinear optical chromophores in block copolymer domains were investigated by encapsulating the chromophores in a linear-diblock copolymer [poly(styrene-b-4-vinylpyridine)] and linear-dendritic (poly(methyl methacrylate)-dendron) block copolymer via hydrogen bonding. Temperature-dependent Fourier transform infrared spectroscopy and morphology evaluation by X-ray scattering and transmission electron microscopy were used with in situ second harmonic generation to correlate domain architectures, processing conditions such as thermal history, and chromophore concentrations with poling efficiency. Poling of chromophores encapsulated in the minority domain (spheres or cylinders) of a linear-diblock copolymer was inhibited by the increasing chromophore concentration within the domain and the chemical nature of the majority domain. Chromophore encapsulation in the majority domain produced the most favorable conditions for poling as measured by in situ second harmonic generation. Thermal annealing of the linear-diblock copolymer/chromophore composites resulted in chromophore aggregation with a corresponding decrease in nonlinear optical activity. The linear-dendron/chromophore system presented the most effective architecture for spatially dispersing chromophores. These findings suggest that while well-ordered phase-separated systems such as block copolymers enhance chromophore isolation over homopolymer systems, a more effective approach is to explore polymer chains end functionalized with chromophores.

  18. Nonlinear temperature characteristic of thermal expansion of Grf/Mg composites

    Institute of Scientific and Technical Information of China (English)

    SONG Mei-hui; XIU Zi-yang; WU Gao-hui; CHEN Guo-qin

    2009-01-01

    Graphite fiber reinforced magnesium matrix(Grf/Mg) composites were fabricated by squeeze casting technology. M40 graphite fibers were reinforced to AZ91D and ZM6, their thermal expansion behaviors of M40/AZ91D and M40/ZM6 composites in the temperature range from 20 to 490 ℃ were investigated. The results show that the interfacial species and thermal stress have significant influence on the thermal expansion behavior of the composites. Simultaneously, the longitudinal coefficient of thermal expansion of Grf/Mg composites are affected by the thermal stress, interfacial species and yield strength of matrix alloy, it also decreases with increasing temperature and descending rate of longitudinal coefficient of thermal expansion(CTEs) of Grf/Mg composites changed in different temperature ranges. In terms of different descending rates, the curve of coefficient of thermal expansion vs temperature can be divided into three stages. The matrix alloys M40/AZ91D and M40/ZM6 yield at 170 and 155℃ in the thermal expansion, respectively.

  19. Grey water treatment systems: A review

    NARCIS (Netherlands)

    Abu-Ghunmi, L.N.A.H.; Zeeman, G.; Fayyad, M.; Lier, van J.B.

    2011-01-01

    This review aims to discern a treatment for grey water by examining grey water characteristics, reuse standards, technology performance and costs. The review reveals that the systems for treating grey water, whatever its quality, should consist of processes that are able to trap pollutants with a sm

  20. Grey Literature and the Internet

    Science.gov (United States)

    Hartman, Karen A.

    2006-01-01

    Accreditation standards for professional schools offering social work degrees mandate curriculum content that provides students with skills to analyze, formulate, and influence social policies. An important source of analytical thinking about social policy is the "grey" literature issued by public policy organizations, think tanks,…

  1. Thermal storage and nonlinear heat-transfer characteristics of PCM wallboard

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yinping; Lin, Kunping; Jiang, Yi; Zhou, Guobing [Department of Building Science, Tsinghua University, Beijing 100084 (China)

    2008-07-01

    For the materials with constant thermophysical properties, the thermal performance of wallboards (or floor, ceiling) can be described by decrement factor f and time lag {phi}. However, the phase change material (PCM) may charge large heat during the melting process and discharge large heat during the freezing process, which takes place at some certain temperature or a narrow temperature range. The behavior deviates a lot from the material with constant thermal physical properties. Therefore, it is not reasonable to analyze the thermal performance of PCM wallboard by using the decrement factor f and time lag {phi}. How to simply and effectively analyze the thermal performance of a PCM wallboard is an important problem. In order to analyze and evaluate the energy-efficient effects of the PCM wallboard and floor, two new parameters, i.e., modifying factor of the inner surface heat flux '{alpha}' and ratio of the thermal storage 'b', are put forward. They can describe the thermal performance of PCM external and internal walls, respectively. The analysis and simulation methods are both applied to investigate the effects of different PCM thermophysical properties (heat of fusion H{sub m}, melting temperature T{sub m} and thermal conductivity k) on the thermal performance of PCM wallboard for the residential buildings. The results show that the PCM external wall can save more energy by increasing H{sub m}, decreasing k and selecting proper T{sub m} ({alpha}<1); that the PCM internal wall can save more energy by increasing H{sub m} and selecting appropriate T{sub m}, k. The most energy-efficient approach of applying PCM in a solar house is to apply it in its internal wall. (author)

  2. Impact on Nonlinear Vertical Variation of GNSS Reference Stations Caused by Thermal Expansion

    Directory of Open Access Journals (Sweden)

    JIANG Weiping

    2015-05-01

    Full Text Available Thermal expansion of GPS monuments and nearby bedrock could result in vertical changes in the coordinate time series of GNSS reference stations. In this paper, an improved method was developed to compute the magnitude of vertical variations caused by thermal expansion. Firstly, we calculated the effect on GPS monument and bedrock caused by thermal expansion based on land surface temperature data of GNSS reference stations and thermal expansion model. Secondly, we estimated the circular frequencies, amplitudes and phases using the method of least squares fitting instead of the current method which estimated only the amplitudes and phases information. Finally, we studied the periodic characteristics of the vertical variations caused by our modified thermal expansion model. Through analyzing the results of 9 representative IGS stations, we concluded that thermal expansion of GPS monuments and nearby bedrock could result in vertical variations of GNSS stations. The maximum variations could reach up to 0.57 mm and 1.85 mm at these stations respectively. The vertical variation caused by thermal expansion exhibited both annual and semiannual characteristics, which could explain 11.2% and 3.3% of the total annual and semi-annual variations in the up component of the coordinate time series respectively, and the magnitudes became larger with the increasing of their latitudes. Meanwhile, the amplitudes of the annual variations were much larger than that of the semi-annual variations. Meanwhile, some other small period (about 51 days was also detected at some of these stations. In addition, we chose 107 IGS reference stations and computed the annual amplitudes and phases caused by thermal expansion of all these stations based on the method aforesaid. The results show that the maximum annual amplitude can reach to 3.3 mm, and their magnitudes show positive correlation with their latitudes prominently.

  3. Geometrical method for thermal instability of nonlinearly charged BTZ Black Holes

    CERN Document Server

    Hendi, Seyed Hossein; Panah, Behzad Eslam

    2015-01-01

    In this paper we consider three dimensional BTZ black holes with three models of nonlinear electrodynamics as source. Calculating heat capacity, we study the stability and phase transitions of these black holes. We show that Maxwell, logarithmic and exponential theories yield only type one phase transition which is related to the root(s) of heat capacity. Whereas for correction form of nonlinear electrodynamics, heat capacity contains two roots and one divergence point. Next, we use geometrical approach for studying classical thermodynamical behavior of the system. We show that Weinhold and Ruppeiner metrics fail to provide fruitful results and the consequences of the Quevedo approach are not completely matched to the heat capacity results. Then, we employ a new metric for solving this problem. We show that this approach is successful and all divergencies of its Ricci scalar and phase transition points coincide. We also show that there is no phase transition for uncharged BTZ black holes.

  4. Waveguides induced by grey screening solitons

    Institute of Scientific and Technical Information of China (English)

    Lu Ke-Qing; Zhao Wei; Yang Yan-Long; Zhang Mei-Zhi; Li Jin-Ping; Liu Hong-Jun; Zhang Yan-Peng

    2006-01-01

    We investigate the properties of waveguides induced by one-dimensional grey screening solitons in biased photore-fractive crystals. The results show that waveguides induced by grey screening solitons are always of single mode for all intensity ratios, i.e. the ratios between the peak intensity of the soliton and the dark irradiance. Our analysis indicates that the energy confined near the centre of the grey soliton and the propagation constant of the guided mode of the waveguide induced by the grey screening soliton increase monotonically with intensity ratio increasing. On the other hand, when the soliton greyness increases, the energy confined near the centre of the grey soliton and the propagation constant of the guided mode of the waveguide induced by the grey screening soliton decrease monotonically. Relevant examples are provided where photorefractive crystal is of the strontium barium niobate type.

  5. Study of Heat Transfer with Nonlinear Thermal Radiation on Sinusoidal Motion of Magnetic Solid Particles in a Dusty Fluid

    Science.gov (United States)

    Bhatti, M. M.; Zeeshan, A.; Ellahi, R.

    2016-09-01

    In this article, heat transfer with nonlinear thermal radiation on sinusoidal motion of magnetic solid particles in a dust Jeffrey fluid has been studied. The effects of Magnetohydrodynamic (MHD) and hall current are also taken under consideration. The governing equation of motion and energy equation are modelled with help of Ohms law for fluid and dust phases. The solutions of the resulting ordinary coupled partial differential equations are solved analytically. The impact of all the physical parameters of interest such as Hartmann number, slip parameter, Hall parameter, radiation parameter, Prandtl number, Eckert number and particle volume fraction are demonstrated mathematically and graphically. Trapping mechanism is also discussed in detail by drawing contour lines. The present analysis affirms many interesting behaviours, which permit further study on solid particles motion with heat and mass transfer.

  6. Nonlinear excitations of blood flow in large vessels under thermal radiations and uniform magnetic field

    Science.gov (United States)

    Tabi, C. B.; Motsumi, T. G.; Bansi Kamdem, C. D.; Mohamadou, A.

    2017-08-01

    A nonlinear model of blood flow in large vessels is addressed. The influence of radiations, viscosity and uniform magnetic fields on velocity and temperature distribution waveforms is studied. Exact solutions for the studied model are investigated through the F - expansion method. Based on the choice of parameter values, single-, multi-soliton and Jacobi elliptic function solutions are obtained. Viscosity and permanent magnetic field bring about wave spreading and reduce the velocity of blood, while radiations have reversed effects with strong impact on the waveform frequency of both the velocity and temperature distribution.

  7. Influence of nanoscale temperature rises on photoacoustic generation: Discrimination between optical absorbers based on thermal nonlinearity at high frequency.

    Science.gov (United States)

    Simandoux, Olivier; Prost, Amaury; Gateau, Jérôme; Bossy, Emmanuel

    2015-03-01

    In this work, we experimentally investigate thermal-based nonlinear photoacoustic generation as a mean to discriminate between different types of absorbing particles. The photoacoustic generation from solutions of dye molecules and gold nanospheres (same optical densities) was detected using a high frequency ultrasound transducer (20 MHz). Photoacoustic emission was observed with gold nanospheres at low fluence for an equilibrium temperature around 4 °C, where the linear photoacoustic effect in water vanishes, highlighting the nonlinear emission from the solution of nanospheres. The photoacoustic amplitude was also studied as a function of the equilibrium temperature from 2 °C to 20 °C. While the photoacoustic amplitude from the dye molecules vanished around 4 °C, the photoacoustic amplitude from the gold nanospheres remained significant over the whole temperature range. Our preliminary results suggest that in the context of high frequency photoacoustic imaging, nanoparticles may be discriminated from molecular absorbers based on nanoscale temperature rises.

  8. [Effect of doxorubicine and heterogenous electromagnetic and thermal fields on the nonlinear dynamics of carcinoma Guerin development].

    Science.gov (United States)

    Orel, V E; Dziatkovs'ka, I I; Nikolov, M O; Romanov, A V; Mel'nyk, Iu H; Dziatkovs'ka, N M

    2010-07-01

    While local hyperthermia application the intratumoral blood flow is enhancing, leading to oxygenation and vascular permeability for antitumoral medicines. The work objective was to investigate the dependence of the development kinetics in carcinoma Gereni (CG) from combined action of doxorubicin (DR) and the kind of thermal impact, a contact one--due to a contact delivery of heat from a water heater and without contact - due to the tumor electromagnetic irradiation (EMI) using heterogenous electromagnetic field (EMF). DR was injected to the animals in a mass concentration of 1,5 mg on 1 kg of their body mass. The DR injection, a contact heating and EMI were started on the 8th day after the tumor reinoculation and kept on conducting once a 2 days. The course had included 5 injections and/or 5 seances of a contact heating and/or EMF. The combined action of DR and EMI, using spatially heterogenous EMF of applicator in environment of physiological hyperthermia, have had influenced mostly the inhibition of a nonlinear dynamics in CG development. Antitumoral action of DR in the animals with CG was influenced by thermal and nonthermal effects, which were initiated by spatially heterogenous EMF. Nonlinear dynamics of a CG development in animals did not depend from horizontal direction of isolines of a spatially heterogenous EMF of inductive applicator towards the tumor and duration of the irradiation procedure (15 or 30 minutes) after DR injection. The data obtained were exploited in clinical practice for the inductothermy optimal regimes elaboration while conducting complex treatment of patients, suffering oncological diseases.

  9. Nonlinear Bayesian Algorithms for Gas Plume Detection and Estimation from Hyper-spectral Thermal Image Data

    Energy Technology Data Exchange (ETDEWEB)

    Heasler, Patrick G.; Posse, Christian; Hylden, Jeff L.; Anderson, Kevin K.

    2007-06-13

    This paper presents a nonlinear Bayesian regression algorithm for the purpose of detecting and estimating gas plume content from hyper-spectral data. Remote sensing data, by its very nature, is collected under less controlled conditions than laboratory data. As a result, the physics-based model that is used to describe the relationship between the observed remotesensing spectra, and the terrestrial (or atmospheric) parameters that we desire to estimate, is typically littered with many unknown "nuisance" parameters (parameters that we are not interested in estimating, but also appear in the model). Bayesian methods are well-suited for this context as they automatically incorporate the uncertainties associated with all nuisance parameters into the error estimates of the parameters of interest. The nonlinear Bayesian regression methodology is illustrated on realistic simulated data from a three-layer model for longwave infrared (LWIR) measurements from a passive instrument. This shows that this approach should permit more accurate estimation as well as a more reasonable description of estimate uncertainty.

  10. Cold gas in cluster cores: Global stability analysis and non-linear simulations of thermal instability

    CERN Document Server

    Choudhury, Prakriti Pal

    2015-01-01

    We perform global linear stability analysis and idealized numerical simulations in global thermal balance to understand the condensation of cold gas from hot/virial atmospheres (coronae), in particular the intracluster medium (ICM). We pay particular attention to geometry (e.g., spherical versus plane-parallel) and the nature of the gravitational potential. Global linear analysis gives a similar value for the fastest growing thermal instability modes in spherical and Cartesian geometries. Simulations and observations suggest that cooling in halos critically depends on the ratio of the cooling time to the free-fall time ($t_{cool}/t_{ff}$). Extended cold gas condenses out of the ICM only if this ratio is smaller than a threshold value close to 10. Previous works highlighted the difference between the nature of cold gas condensation in spherical and plane-parallel atmospheres; namely, cold gas condensation appeared easier in spherical atmospheres. This apparent difference due to geometry arises because the prev...

  11. Influence of nonlinear thermal radiation and viscous dissipation on three-dimensional flow of Jeffrey nano fluid over a stretching sheet in the presence of Joule heating

    Science.gov (United States)

    Ganesh Kumar, K.; Rudraswamy, N. G.; Gireesha, B. J.; Krishnamurthy, M. R.

    2017-09-01

    Present exploration discusses the combined effect of viscous dissipation and Joule heating on three dimensional flow and heat transfer of a Jeffrey nanofluid in the presence of nonlinear thermal radiation. Here the flow is generated over bidirectional stretching sheet in the presence of applied magnetic field by accounting thermophoresis and Brownian motion of nanoparticles. Suitable similarity transformations are employed to reduce the governing partial differential equations into coupled nonlinear ordinary differential equations. These nonlinear ordinary differential equations are solved numerically by using the Runge-Kutta-Fehlberg fourth-fifth order method with shooting technique. Graphically results are presented and discussed for various parameters. Validation of the current method is proved by comparing our results with the existing results under limiting situations. It can be concluded that combined effect of Joule and viscous heating increases the temperature profile and thermal boundary layer thickness.

  12. Growth, mechanical, dielectric, thermal and optical studies of a nonlinear optical crystal: L-Histidinium dipicrate dihydrate

    Energy Technology Data Exchange (ETDEWEB)

    Helen, F.; Kanchana, G., E-mail: kanchanagac@gmail.com

    2015-02-01

    Nonlinear optical single crystals of L-histidinium dipicrate dihydrate (LHDPDH) were grown by slow evaporation solution growth technique at room temperature. The microstructure and growth features were analysed by chemical etching. The grown crystal was subjected to X-ray diffraction analysis to confirm its purity and crystal structure. Mechanical behaviour of the grown crystal was analysed by Vicker's microhardness test. The stiffness constant was evaluated for various loads. The dielectric behaviour was investigated at different frequencies and temperatures. AC conductivity and activation energy were determined. Electronic properties, such as valence electron plasma energy, average energy gap or Penn gap, Fermi energy and electronic polarizability were calculated. Thermal analysis confirmed the association of two water molecules in the crystal lattice of LHDPDH and revealed the thermal stability of the crystal. Photoconductivity study reveals that LHDPDH exhibits positive photoconductivity. The optical transmission window and optical band gap of the crystal were found by UV–vis–NIR studies. Second harmonic generation efficiency was found to be 2.5 times that of the standard KDP crystal. The laser damage threshold for the grown crystal was measured using Nd:YAG laser. - Highlights: • High stiffness constant indicates strong binding forces between ions. • Low dielectric constant and dielectric loss at high frequencies. • LHDPDH crystal shows positive photoconductivity. • The laser damage threshold is found to be higher than urea. • SHG efficiency is 2.5 times that of KDP.

  13. An FMEA analysis using grey theory and grey rough sets

    Directory of Open Access Journals (Sweden)

    Farshad Faezy Razi

    2013-10-01

    Full Text Available This paper presents a hybrid method for detecting the most important failure items as well as the most effective alternative strategy to cope with possible events. The proposed model of this paper uses grey technique to rank various alternatives and FMEA technique to find important faults. The implementation of the proposed method has been illustrated for an existing example on the literature. The results of this method show that the proposed model has been capable of detecting the most trouble making problems with fuzzy logic and finds the most important solution strategy using FMEA technique.

  14. Grey Literature in the Czech Republic

    OpenAIRE

    Pejsova, Petra (NTK); Pfeiferova, Martina (NTK); GreyNet, Grey Literature Network Service

    2008-01-01

    Our contribution summarizes and describes activities concerning grey literature in the Czech Republic. The managing organisation of the activity is the State Technical Library (henceforth the STL); in the past, it was the STL, who was collecting, publishing and submitting grey literature into the SIGLE system. Moreover, the STL was the representative of the Czech Republic in the EAGLE. Now, EAGLE being extinct, there is no coordinated collection of grey literature on the national level since ...

  15. Structural, Thermal, Linear and Nonlinear Optical Studies on New NLO Crystal∶DL-Threonium Trichloroacetate

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Crystals of DL-threonium trichloroacetate (DLTTCA) was synthesized from an aqueous solution by slow evaporation technique. The grown crystals were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, UV-Vis-NIR and SHG measurements. Vibrational structure of the crystal was elucidated from FTIR analysis and the hydrogen bond interactions were discussed in detail. The ultraviolet transparent cutoff falls at 212 nm. Thermal stability of the compound was also studied. The powder SHG efficiency of the compound was measured as 0.62 times to that of KDP.

  16. Economic Load Dispatch Using Grey Wolf Optimization

    Directory of Open Access Journals (Sweden)

    Dr.Sudhir Sharma

    2015-04-01

    Full Text Available This paper presents grey wolf optimization (GWO to solve convex economic load dispatch (ELD problem. Grey Wolf Optimization (GWO is a new meta-heuristic inspired by grey wolves. The leadership hierarchy and hunting mechanism of the grey wolves is mimicked in GWO. The objective of ELD problem is to minimize the total generation cost while fulfilling the different constraints, when the required load of power system is being supplied. The proposed technique is implemented on two different test systems for solving the ELD with various load demands. To show the effectiveness of GWO to solve ELD problem results were compared with other existing techniques.

  17. [Spectral quantitative analysis by nonlinear partial least squares based on neural network internal model for flue gas of thermal power plant].

    Science.gov (United States)

    Cao, Hui; Li, Yao-Jiang; Zhou, Yan; Wang, Yan-Xia

    2014-11-01

    To deal with nonlinear characteristics of spectra data for the thermal power plant flue, a nonlinear partial least square (PLS) analysis method with internal model based on neural network is adopted in the paper. The latent variables of the independent variables and the dependent variables are extracted by PLS regression firstly, and then they are used as the inputs and outputs of neural network respectively to build the nonlinear internal model by train process. For spectra data of flue gases of the thermal power plant, PLS, the nonlinear PLS with the internal model of back propagation neural network (BP-NPLS), the non-linear PLS with the internal model of radial basis function neural network (RBF-NPLS) and the nonlinear PLS with the internal model of adaptive fuzzy inference system (ANFIS-NPLS) are compared. The root mean square error of prediction (RMSEP) of sulfur dioxide of BP-NPLS, RBF-NPLS and ANFIS-NPLS are reduced by 16.96%, 16.60% and 19.55% than that of PLS, respectively. The RMSEP of nitric oxide of BP-NPLS, RBF-NPLS and ANFIS-NPLS are reduced by 8.60%, 8.47% and 10.09% than that of PLS, respectively. The RMSEP of nitrogen dioxide of BP-NPLS, RBF-NPLS and ANFIS-NPLS are reduced by 2.11%, 3.91% and 3.97% than that of PLS, respectively. Experimental results show that the nonlinear PLS is more suitable for the quantitative analysis of glue gas than PLS. Moreover, by using neural network function which can realize high approximation of nonlinear characteristics, the nonlinear partial least squares method with internal model mentioned in this paper have well predictive capabilities and robustness, and could deal with the limitations of nonlinear partial least squares method with other internal model such as polynomial and spline functions themselves under a certain extent. ANFIS-NPLS has the best performance with the internal model of adaptive fuzzy inference system having ability to learn more and reduce the residuals effectively. Hence, ANFIS-NPLS is an

  18. Weak Nonlinear Thermal Instability Under Vertical Magnetic Field, Temperature Modulation And Heat Source

    Directory of Open Access Journals (Sweden)

    B.S. Bhadauria

    2014-02-01

    Full Text Available The present paper deals with a weak nonlinear stability problem of magneto-convection in an electrically conducting Newtonian liquid, confined between two horizontal surfaces, under a constant vertical magnetic field, and subjected to an imposed time-periodic boundary temperature (ITBT along with internal heating effects. In the case of (ITBT, the temperature gradient between the walls of the fluid layer consists of a steady part and a time-dependent oscillatory part. The temperature of both walls is modulated in this case. The disturbance is expanded in terms of power series of amplitude of convection, which is assumed to be small. It is found that the response of the convective system to the internal Rayleigh number is destabilizing. Using Ginzburg-Landau equation, the effect of modulations on heat transport is analyzed. Effect of various parameters on the heat transport is also discussed. Further, it is found that the heat transport can be controlled by suitably adjusting the external parameters of the system.

  19. The luminous and the grey

    CERN Document Server

    Batchelor, David

    2014-01-01

    Color surrounds us: the lush green hues of trees and grasses, the variant blues of water and the sky, the bright pops of yellow and red from flowers. But at the same time, color lies at the limits of language and understanding. In this absorbing sequel to Chromophobia-which addresses the extremes of love and loathing provoked by color since antiquity-David Batchelor charts color's more ambiguous terrain.   The Luminous and the Grey explores the places where color comes into being and where it fades away, probing when it begins and when it ends both in the imagination and in the material world.

  20. Simulation and Prediction of Alkalinity in Sintering Process Based on Grey Least Squares Support Vector Machine

    Institute of Scientific and Technical Information of China (English)

    SONG Qiang; WANG Ai-min

    2009-01-01

    The prediction of the alkalinity is difficult during the sintering process. Whether or not the level of the alkalinity of sintering process is successful is directly related to the quality of sinter. There is no very good method for predicting the alkalinity by now owing to the high complexity, high nonlinearity, strong coupling, high time delay, and etc. Therefore, a new technique, the grey squares support machine, was introduced. The grey support vector machine model of the alkalinity enabled the development of new equation and algorithm to predict the alkalinity. During modelling, the fluctuation of data sequence was weakened by the grey theory and the support vector machine was capable of processing nonlinear adaptable information, and the grey support vector machine has a combination of those advantages. The results revealed that the alkalinity of sinter could be accurately predicted using this model by reference to small sample and information. The experimental results showed that the grey support vector machine model was effective and practical owing to the advantages of high precision, less samples required, and simple calculation.

  1. Solitary, explosive and rational solutions for nonlinear electron-acoustic waves with non-thermal electrons

    CERN Document Server

    El-Wakil, S A; Abd-El-Hamid, H M; Abulwafa, E M

    2010-01-01

    A rigorous theoretical investigation has been made on electron acoustic wave propagating in unmagnetized collisionless plasma consisting of a cold electron fluid, non-thermal hot electrons and stationary ions. Based on the pseudo-potential approach, large amplitude potential structures and the existence of solitary waves are discussed. The reductive perturbation method has been employed to derive the Korteweg-de Vries (KdV) equation for small but finite amplitude electrostatic waves. An algebraic method with computerized symbolic computation, which greatly exceeds the applicability of the existing tanh, extended tanh methods in obtaining a series of exact solutions of the KdV equation. Numerical studies have been made using plasma parameters close to those values corresponding to the dayside auroral zone reveals different solutions i.e., bell-shaped solitary pulses, rational pulses and solutions with singularity at a finite points which called blowup solutions in addition to the propagation of an explosive pu...

  2. 基于灰关联理论的橡胶粉改性沥青热老化性能研究%Research on Thermal Ageing Performance of Rubber Powder Modified Asphalt Based on Grey Associative Theory

    Institute of Scientific and Technical Information of China (English)

    王宝松; 叶奋

    2012-01-01

    This paper analyzes influences of preparation technology of rubber asphalt on ageing performance of rubber asphalt based on grey associative theory. In order to guarantee accuracy of research on ageing performance of rubber asphalt, .the paper adopts the isolated variable method to test by fixing other factors and transforming single factor and analyze influences of various factors on performance of rubber asphalt. The paper employs grey associative analysis method to analyze degrees of association of multiple groups of data, to study degrees of, association of all influence factors with ageing performance of rubber asphalt, and to determine key factors that affect ageing performance of rubber asphalt.%基于灰关联理论,分析橡胶沥青制备工艺对橡胶沥青老化性能的影响.为保证橡胶沥青老化性能研究的准确性,采用“孤立变量法”,通过固定其他因素并变换单个因素进行试验,分析各种因素对橡胶沥青性能的影响.采用灰关联分析方法对多组数据进行关联度分析,研究各影响因素与橡胶沥青老化性能的关联度大小,确定影响橡胶沥青老化性能的关键因素.

  3. Non-Linear Thermal Lens Signal of the (Δυ = 6) C-H Vibrational Overtone of Benzene in Liquid Solutions of Hexane

    Science.gov (United States)

    Nyaupane, Parashu R.; Manzanares, Carlos

    2016-06-01

    The thermal lens technique is applied to vibrational overtone spectroscopy of solutions of benzene. The pump and probe thermal lens technique has been found to be very sensitive for detecting samples of low concentration in transparent solvents. The C-H fifth vibrational (Δυ = 6) overtone spectrum of benzene is detected at room temperature for compositions per volume in the range (1 to 1× 10-4) using n-C_6H14 as the solvent. By detecting the absorption band in a 100 ppm solution, the peak absorption of the signal is approximately (2.2 ± 0.3)× 10-7 cm-1. The parameters that determine the magnitude of the thermal lens signal such as the pump laser power and the thermodynamic properties of the solvent and solute are discussed. A plot of normalized integrated intensity as a function of composition of benzene in solution reveals a non-linear behavior. The non-linearity cannot be explained assuming solvent enhancement at low concentrations. A two color absorption model that includes the simultaneous absorption of the pump and probe lasers could explain the enhanced magnitude and the non-linear behavior of the thermal lens signal for solutions of composition below 0.01.

  4. Locating grey literature on communication disorders.

    Science.gov (United States)

    Shpilko, Inna

    2005-01-01

    This article provides an overview of selected Web-based resources containing grey literature in the area of communication disorders. It is geared to practitioners, researchers, students, and consumers seeking reliable, freely available scientific information. Grey (or gray) literature has been defined as "that which is produced on all levels of government, academics, business, and industry in print and electronic formats, but which is not controlled by commercial publishers."1 This paper reviews various general reference sources potentially containing grey literature on communication disorders. This review includes identification of the methods specialists in this field use to obtain this valuable, yet often overlooked, literature. Access points and search tools for identifying grey literature on communication disorders are recommended. Commercial databases containing grey literature are not included. Conclusions presented in this article are considered complementary to traditionally published information resources on communication disorders, such as scholarly journals, online databases, etc.

  5. Study of Growth, Structural, Thermal and Nonlinear Optical Properties of Silica Gel Grown Calcium Iodate Monohydrate Crystals

    Directory of Open Access Journals (Sweden)

    Sharda J. Shitole

    2015-12-01

    Full Text Available Single crystals of calcium iodate, monohydrate [Ca (IO32, H2O] were grown by simple gel technique by single and double diffusion method. Morphologies and habit faces like prismatic, prismatic pyramidal, needle shaped, hopper crystals were obtained. Few crystals were opaque, some were translucent and some good quality transparent crystals were obtained. EDAX spectrum verified that crystals are of calcium iodate, monohydrate indeed and was used to find Atomic % and Weight %. Unit cell parameters were obtained from the X-ray diffractogram. The calculated unit cell parameters, β, and‘d’ values are in good agreement with reported ones. Structural analysis was done by using FTIR spectroscopy which confirmed the presence of fundamental infrared frequencies, generally observed in all iodate compounds. Thermal analysis exhibits three steps explicitly on heating the samples. The first step involves dehydration at 5500C, second step shows decomposition at 5800C, and the third step involves again decomposition at 6400C. Powder second harmonic generation experiments exhibit the nonlinear nature of the substance.

  6. Growth, thermal, dielectric and mechanical properties of L-phenylalanine-benzoic acid: A nonlinear optical single crystal

    Science.gov (United States)

    Tamilselvan, S.; Vimalan, M.; Vetha Potheher, I.; Rajasekar, S.; Jeyasekaran, R.; Antony Arockiaraj, M.; Madhavan, J.

    2013-10-01

    An efficient amino acid family nonlinear optical single crystal L-phenylalanine-benzoic acid (LPB) was conveniently grown by slow evaporation technique at room temperature. The crystal system and the lattice parameters were analyzed by single crystal X-ray diffraction studies. The grown crystal has excellent transmission in the entire visible region and its lower cut-off wavelength was found to be 248 nm. The SHG efficiency of the grown crystal was found to be 1.6 times higher than that of KDP crystal. The Laser damage threshold value of LPB has been found to be 6.5 GW/cm2. The sample was thermally stable up to 134 °C. Microhardness, dielectric and AC/DC conductivity measurements were made along (0 0 1) plane and reported for the first time. Microhardness studies revealed that the sample belongs to hard nature. Frequency dependent dielectric constant was measured for different temperatures and found maximum dielectric constant of 14 for 363 K. Photoconductivity studies of LPB divulged its negative photoconducting nature.

  7. Finite width of the sonic event horizon and grey body Hawking radiation

    CERN Document Server

    Vinish, Y

    2014-01-01

    Finite width of the analog event horizon is determined by the nonlinearity length in the Kerr nonlinear optical system, which is discussed here, or by the healing length in Bose-Einstein condensates. The various eigen modes of fluctuations are found in the immediate vicinity of the event horizon and the scattering matrix due to the finite width horizon is calculated to within the leading order correction in the nonlinearity length. The Hawking radiation is found to be that of a grey body with the emissivity larger than one. A procedure of paraxial quantization of the fluctuation field is discussed and its connection to the conventional quantization of the electromagnetic field is demonstrated.

  8. Fifteenth International Conference on Grey Literature: The Grey Audit: A Field Assessment in Grey Literature

    OpenAIRE

    Pejšová, Petra; Vyčítalová, Hana

    2013-01-01

    Účelem zahraniční služební cesty byla účast PhDr. Petry Pejšové a Mgr. Hany Vyčítalové na dvoudenní konferenci „Fifteenth International Conference on Grey Literature“ v Bratislavě. Konference se koná každý rok, zaměřuje se na problematiku šedé literatury a mezinárodní odbornou diskusi o šedé literatuře. Na konferenci byl prezentován poster s názvem „Survey of Enhanced Publications in the Czech Republic“.

  9. A research on grey numerical imitation and modeling of groundwater seepage system

    Institute of Scientific and Technical Information of China (English)

    WU; Qiang

    2001-01-01

    [1]Jiao Jiujiu, Grey hydrogeologic system analysis and time series model, Survey Science and Technology (in Chinese), 1987,(10): 39-43.[2]Li Shuwen, Wang Baolai, Xiao Guoqiang, A compound model of grey and periodic scrape and its application in groundwater prediction, Journal of Hebei Institute of Architectural Science & Technology (in Chinese), 1992, (3): 246-251.[3]Wang Qingyin, Li Shuwen, Grey distributed parameter model and groundwater analog, Journal of Hebei Institute of Architectural Science & Technology (in Chinese), 1992, (3): 66-70.[4]Guo Chunqing, Xia Riyuan, Liu Zhenglin, Gray Systematic Theory and Methodological Study of Krast Groundwater Resources Evaluation (in Chinese), Beijing: Geological Publishing House, 1993, 3-60.[5]Wang Qingyin, Liu Kaidi, The Mathematical Method of Grey Systematic Theory and Its Application (in Chinese), Chengdu: Publishing House of Southwestern China University of Communication, 1990, 23-27.[6]Wang Qingyin, Wu Heqing, The concept of grey number and its property, in Proceedings of NAFIPS98, USA, 1998,45-49.[7]Givoli, D., Doukhovni, I., Finite element programming approach for contact problems with geometrical nonlinearity, Computers and Structures, 1996, (8): 31-41.[8]Li Shuwen, Wang Zhiqiang, Wu Qiang, The superiority of storage-centered finite element method in solving seepage problem, Coal Geology and Exploration (in Chinese), 1999, (5): 46-49.

  10. Effect of nonlinear thermal radiation on non-aligned bio-convective stagnation point flow of a magnetic-nanofluid over a stretching sheet

    Directory of Open Access Journals (Sweden)

    M. Jayachandra Babu

    2016-09-01

    Full Text Available The current study covers the relative study of non-aligned magnetohydrodynamic stagnation point flow of a nanofluid comprising gyrotactic microorganisms across a stretching sheet in the presence of nonlinear thermal radiation and variable viscosity. The governing equations transitioned as nonlinear ordinary differential equations with suited similarity transformations. With the assistance of Runge-Kutta based shooting method, we derived solutions. Results for oblique and free stream flow cases are exhibited through plots for the parameters of concern. In tabular form, heat and mass transfer rate along with the local density of the motile microorganisms are analyzed for some parameters. It is found that local density of the motile microorganisms is highly influenced by the Biot and Peclet numbers. Rising values of the magnetic field parameter, Biot number, thermal radiation parameter and thermophoresis parameter increase the thermal boundary layer. Bioconvection Peclet number and bioconvection Lewis number have tendency to reduce the density of the motile microorganisms. It is also found that thermal and concentration boundary layers become high in free stream flow when compared with the oblique flow.

  11. Grey-Markov Model for Road Accidents Forecasting

    Institute of Scientific and Technical Information of China (English)

    李相勇; 严余松; 蒋葛夫

    2003-01-01

    In order to improve the forecasting precision of road accidents, by introducing Markov chains forecasting method, a grey-Markov model for forecasting road accidents is established based on grey forecasting method. The model combines the advantages of both grey forecasting method and Markov chains forecasting method, overcomes the influence of random fluctuation data on forecasting precision and widens the application scope of the grey forecasting. An application example is conducted to evaluate the grey-Markov model, which shows that the precision of the grey-Markov model is better than that of grey model in forecasting road accidents.

  12. The 'grey' assessment practice of IA screening

    DEFF Research Database (Denmark)

    Bidstrup, Morten

    2017-01-01

    ’ in Denmark. This article explores the prevalence, influence and applied rationale of grey IA. Through a questionnaire, data was collected from 121 IA practitioners working within the fields of environmental impact assessment and strategic environmental assessment. It was found that grey IA is a common......Research focusing on the practices surrounding screening in Impact Assessment (IA) is limited. Yet, it has been found that development proposals sometimes are adjusted through an informal dialog with IA practitioners prior to or during screening. Such practice is often referred to as ‘grey IA...... practice, which influences the outcomes of formal screening procedures through consideration of impacts on neighbours and spatial zones of protection. Grey IA is to some extent motivated by the opportunity to save the resources required for full-scale IA, but an additional ‘green’ rationale also exists...

  13. Study on the Grey Polynomial Geometric Programming

    Institute of Scientific and Technical Information of China (English)

    LUODang

    2005-01-01

    In the model of geometric programming, values of parameters cannot be gotten owing to data fluctuation and incompletion. But reasonable bounds of these parameters can be attained. This is to say, parameters of this model can be regarded as interval grey numbers. When the model contains grey numbers, it is hard for common programming method to solve them. By combining the common programming model with the grey system theory,and using some analysis strategies, a model of grey polynomial geometric programming, a model of 8 positioned geometric programming and their quasi-optimum solution or optimum solution are put forward. At the same time, we also developed an algorithm for the problem.This approach brings a new way for the application research of geometric programming. An example at the end of this paper shows the rationality and feasibility of the algorithm.

  14. Grey literature:from hidden to visible

    OpenAIRE

    Pejšová, Petra

    2012-01-01

    Grey literature is information produced on all levels of government, academics, business and industry in electronic and print formats not controlled by commercial publishing i.e. where publishing is not the primary activity of the producing body. (Luxembourg, 1997 - Expanded in New York, 2004, on WWW: http://www.greynet.org/index.html) The role of grey literature in today society was well expressed by Vaska: “It is therefore remarkable how efforts over the past two decades have altered origi...

  15. Expanding the Horizon of Grey Literature

    OpenAIRE

    Mackenzie Owen, John; GreyNet, Grey Literature Network Service

    1998-01-01

    Grey literature - loosely defined as information distributed directly by its creator - is gaining importance due to the development of digital information networks. Individuals and organizations are using these networks, making vast amounts of information available on a global scale. The role and added value of traditional publishers and libraries is being questioned. Some argue that grey literature will become more important than published literature; others disagree. During the Third Intern...

  16. Grey Literature in Energy: 5 Years Later

    OpenAIRE

    Cutler, Deborah E. (OSTI-DOE); GreyNet, Grey Literature Network Service

    2004-01-01

    At GL'99, the Department of Energy's Office of Scientific and Technical Information (DOE OSTI) presented a paper titled "Grey Literature in Energy: a Shifting Paradigm". Five years later, the paradigm continues to shift, less radically than the change from paper and microfiche to electronic, but with significant benefit to users worldwide. OSTI's efforts continue this shift, moving even further away from the connotation of "grey" as meaning "hard to get" literature. Along with its domestic an...

  17. Link managers for grey literature

    CERN Document Server

    Lodi-Rizzini, E; Vigen, Jens

    1999-01-01

    In the self service area of the library reading rooms it is required to organise the collections in the simplest way possible. This is an important feature for readers making it possible to a get direct access to the material without necessarily having to go via the library catalogue to retrieve the call number. A typical example will be that a collection is organised so that a reader easily can get directly from an article reference to the article itself in a library where the journal collection simply is organised alphabetically. This requirement seems to have been forgotten by many of the most important actors in the digital library, both by the commercial publishers and many of the bodies producing grey literature. How are the users supposed to get directly to Report XXX without having to navigate through n different web pages? This is on top happening in "The Library" which is intended to be close up to 100 based on self service! CERN Library has developed a mechanism, "Go direct", which handles the prob...

  18. Disturbed grey matter coupling in schizophrenia.

    Science.gov (United States)

    Collin, Guusje; de Reus, Marcel A; Cahn, Wiepke; Hulshoff Pol, Hilleke E; Kahn, René S; van den Heuvel, Martijn P

    2013-01-01

    In schizophrenia, grey matter deficits have been shown for many regions throughout the brain. These regions do not operate in isolation. Rather, they form a structural network of interconnected grey matter regions. To examine the mutual dependence of brain regions, this study investigated interregional coupling in lobar and regional grey matter volumes obtained from 146 schizophrenia patients and 122 healthy comparison subjects. Compared to healthy controls, schizophrenia patients showed both decreased (e.g. between left frontal and bilateral subcortical, p≤0.005) and increased (e.g. between left temporal and bilateral subcortical, p≤0.001) coupling between lobar grey matter volumes. On a regional scale, decreased coupling was most pronounced between fronto-parietal cortical regions and subcortical structures, and between frontal and occipital regions. In addition, an increased association was found among frontal and limbic regions, and for temporo-occipital connexions. Consistent with dysconnectivity theories of schizophrenia, impaired grey matter coupling may be reflective of reduced integrity of the brain's network. Furthermore, as cross-sectional volumetric coupling is indicative of maturational coupling, aberrant grey matter coupling may be a marker of neurodevelopmental abnormalities in schizophrenia.

  19. Growth, spectral, optical, thermal, surface analysis and third order nonlinear optical properties of an organic single crystal: 1-(2-Methyl-6-nitro-4-phenyl-3-quinolyl) ethanone.

    Science.gov (United States)

    Nirosha, M; Kalainathan, S; Sarveswari, S; Vijayakumar, V; Srikanth, A

    2015-02-25

    Single crystal of 1-(2-Methyl-6-nitro-4-phenyl-3-quinolyl) ethanone was grown using slow evaporation solution growth technique. Single crystal X-ray diffraction study reveals the lattice parameters of the grown crystal. The modes of vibration of different molecular groups present in 2M6NQE were identified by FTIR spectral analysis. Its optical behavior was examined through UV-vis-NIR absorption and PL emission spectrum. They signify that the crystal has transparency in the region between 383 and 1100 nm. The PL spectrum of the title compound shows green emission in the crystal. From the thermal analysis, 2M6NQE has found to be thermally stable up to 263°C, and the melting point of the material is 170°C. The estimations of third order non-linear optical properties like non-linear absorption coefficient (β), non-linear refractive index (n2) and susceptibility [χ(3)] were calculated using Z-scan technique. It has observed that, crystal exhibits reverse saturation absorption and self-defocusing performance. Etching study was carried out for the grown crystal using different solvents. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Thermally stimulated third-order optical nonlinearity in Cd-doped CuO-PVA thin films under cw laser illumination

    Science.gov (United States)

    Tamgadge, Y. S.; Pahurkar, V. G.; Talwatkar, S. S.; Sunatkari, A. L.; Muley, G. G.

    2015-08-01

    We report synthesis, linear and third-order nonlinear optical properties of Cd-doped CuO-PVA nanocomposite thin films. Cd-doped CuO nanoparticles (NPs) were obtained by chemical synthesis method, and spin coating technique was used to obtain thin films in polyvinyl alcohol matrix. X-ray diffraction (XRD) shows formation of crystalline CuO having monoclinic phase with average particle size of 10 nm. Ultraviolet-visible (UV-Vis) spectroscopy attests formation of NPs by witnessing strong blue shift in the excitonic absorption. Absorption wavelength of CuO NPs shifts from 365 to 342 nm for Cd doping of 1-5 wt%. Both XRD and UV-Vis data confirm decrease in particle size with increase in Cd-doping concentration. Thin films have been characterized by Z-scan technique under continuous-wave He-Ne laser, and enhanced values of nonlinear refractive index n 2 and nonlinear absorption coefficient β have been obtained. Enhancements in the nonlinear optical properties have been attributed to the thermal effect due to strong linear absorption coefficient combined with increased thermo-optic coefficient. Contributing mechanisms such as photoacoustic effect, surface states effect and dielectric effect due to dopant and thin film structure have been discussed.

  1. Nonlinear convective analysis of a rotating Oldroyd-B nanofluid layer under thermal non-equilibrium utilizing Al2O3-EG colloidal suspension

    Science.gov (United States)

    Agarwal, Shilpi; Rana, Puneet

    2016-04-01

    In this paper, we examine a layer of Oldroyd-B nanofluid for linear and nonlinear regimes under local thermal non-equilibrium conditions for the classical Rayleigh-Bénard problem. The free-free boundary condition has been implemented with the flux for nanoparticle concentration being zero at edges. The Oberbeck-Boussinesq approximation holds good and for the rotational effect Coriolis term is included in the momentum equation. A two-temperature model explains the effect of local thermal non-equilibrium among the particle and fluid phases. The criteria for onset of stationary convection has been derived as a function of the non-dimensionalized parameters involved including the Taylor number. The assumed boundary conditions negate the possibility of overstability due to the absence of opposing forces responsible for it. The thermal Nusselt number has been obtained utilizing a weak nonlinear theory in terms of various pertinent parameters in the steady and transient mode, and has been depicted graphically. The main findings signify that the rotation has a stabilizing effect on the system. The stress relaxation parameter λ_1 inhibits whereas the strain retardation parameter λ_2 exhibits heat transfer utilizing Al2O3 nanofluids.

  2. Thermal radiation and chemical reaction effects on boundary layer slip flow and melting heat transfer of nanofluid induced by a nonlinear stretching sheet

    Science.gov (United States)

    Krishnamurthy, M. R.; Gireesha, B. J.; Prasannakumara, B. C.; Gorla, Rama Subba Reddy

    2016-09-01

    A theoretically investigation has been performed to study the effects of thermal radiation and chemical reaction on MHD velocity slip boundary layer flow and melting heat transfer of nanofluid induced by a nonlinear stretching sheet. The Brownian motion and thermophoresis effects are incorporated in the present nanofluid model. A set of proper similarity variables is used to reduce the governing equations into a system of nonlinear ordinary differential equations. An efficient numerical method like Runge-Kutta-Fehlberg-45 order is used to solve the resultant equations for velocity, temperature and volume fraction of the nanoparticle. The effects of different flow parameters on flow fields are elucidated through graphs and tables. The present results have been compared with existing one for some limiting case and found excellent validation.

  3. Spinal cord grey matter segmentation challenge.

    Science.gov (United States)

    Prados, Ferran; Ashburner, John; Blaiotta, Claudia; Brosch, Tom; Carballido-Gamio, Julio; Cardoso, Manuel Jorge; Conrad, Benjamin N; Datta, Esha; Dávid, Gergely; Leener, Benjamin De; Dupont, Sara M; Freund, Patrick; Wheeler-Kingshott, Claudia A M Gandini; Grussu, Francesco; Henry, Roland; Landman, Bennett A; Ljungberg, Emil; Lyttle, Bailey; Ourselin, Sebastien; Papinutto, Nico; Saporito, Salvatore; Schlaeger, Regina; Smith, Seth A; Summers, Paul; Tam, Roger; Yiannakas, Marios C; Zhu, Alyssa; Cohen-Adad, Julien

    2017-03-07

    An important image processing step in spinal cord magnetic resonance imaging is the ability to reliably and accurately segment grey and white matter for tissue specific analysis. There are several semi- or fully-automated segmentation methods for cervical cord cross-sectional area measurement with an excellent performance close or equal to the manual segmentation. However, grey matter segmentation is still challenging due to small cross-sectional size and shape, and active research is being conducted by several groups around the world in this field. Therefore a grey matter spinal cord segmentation challenge was organised to test different capabilities of various methods using the same multi-centre and multi-vendor dataset acquired with distinct 3D gradient-echo sequences. This challenge aimed to characterize the state-of-the-art in the field as well as identifying new opportunities for future improvements. Six different spinal cord grey matter segmentation methods developed independently by various research groups across the world and their performance were compared to manual segmentation outcomes, the present gold-standard. All algorithms provided good overall results for detecting the grey matter butterfly, albeit with variable performance in certain quality-of-segmentation metrics. The data have been made publicly available and the challenge web site remains open to new submissions. No modifications were introduced to any of the presented methods as a result of this challenge for the purposes of this publication.

  4. Inverse analysis of thermal conductivities in transient non-homogeneous and non-linear heat conductions using BEM based on complex variable differentiation method

    Science.gov (United States)

    Yu, XiaoChun; Bai, YuGuang; Cui, Miao; Gao, XiaoWei

    2013-05-01

    This paper presents a new inverse analysis approach to sensitivity analysis and material property identification in transient non-homogeneous and non-linear heat conduction Boundary Element Method (BEM) analysis based on Complex Variable Differentiation Method (CVDM). In this approach, the material properties are taken as the optimization variables, and the sensitivity coefficients are computed by CVDM. The advantages of using CVDM are that the computation of partial derivatives of an implicit function is reduced to function calculation in a complex domain, and the parameter sensitivity coefficients can be determined in a more accurate way than the traditional Finite Difference Method (FDM). Based on BEM and CVDM in evaluation of the sensitivity matrix of heat flux, the parameter such as thermal conductivity can be accurately identified. Six numerical examples are given to demonstrate the potential of the proposed approach. The results indicate that the presented method is efficient for identifying the thermal conductivity with single or multiple parameters.

  5. Effect of hall current on MHD flow of a nanofluid with variable properties due to a rotating disk with viscous dissipation and nonlinear thermal radiation

    Science.gov (United States)

    Abdel-Wahed, Mohamed; Akl, Mohamed

    2016-09-01

    Analysis of the MHD Nanofluid boundary layer flow over a rotating disk with a constant velocity in the presence of hall current and non-linear thermal radiation has been covered in this work. The variation of viscosity and thermal conductivity of the fluid due to temperature and nanoparticles concentration and size is considered. The problem described by a system of P.D.E that converted to a system of ordinary differential equations by the similarity transformation technique, the obtained system solved analytically using Optimal Homotopy Asymptotic Method (OHAM) with association of mathematica program. The velocity profiles and temperature profiles of the boundary layer over the disk are plotted and investigated in details. Moreover, the surface shear stress, rate of heat transfer explained in details.

  6. Nonlinear Effect of Moisture Content on Effective Thermal Conductivity of Building Materials with Different Pore Size Distributions

    Science.gov (United States)

    Liu, Yanfeng; Ma, Chao; Wang, Dengjia; Wang, Yingying; Liu, Jiaping

    2016-06-01

    Understanding the quantitative relationship between the effective thermal conductivity and the moisture content of a material is required to accurately calculate the envelope heat and mass transfer and, subsequently, the building energy consumption. We experimentally analyzed the pore size distributions and porosities of common building materials and the influence of the moisture content on the effective thermal conductivity of building materials. We determined the quantitative relationship between the effective thermal conductivity and moisture content of building materials. The results showed that a larger porosity led to a more significant effect of the moisture content on the effective thermal conductivity. When the volumetric moisture content reached 10 %, the thermal conductivities of foam concrete and aerated concrete increased by approximately 200 % and 100 %, respectively. The effective thermal conductivity increased rapidly in the low moisture content range and increased slowly in the high moisture content range. The effective thermal conductivity is related to the moisture content of the materials through an approximate power function. As the moisture content in the walls of a new building stabilizes, the effective thermal conductivity of normal concrete varies only slightly, whereas that of aerated concrete varies more significantly. The effective thermal conductivity of the material is proportional to the relative humidity of the environment. This trend is most noticeable when the wall material is aerated concrete.

  7. Equivalency and unbiasedness of grey prediction models

    Institute of Scientific and Technical Information of China (English)

    Bo Zeng; Chuan Li; Guo Chen; Xianjun Long

    2015-01-01

    In order to deeply research the structure discrepancy and modeling mechanism among different grey prediction mo-dels, the equivalence and unbiasedness of grey prediction mo-dels are analyzed and verified. The results show that al the grey prediction models that are strictly derived from x(0)(k) +az(1)(k) = b have the identical model structure and simulation precision. Moreover, the unbiased simulation for the homoge-neous exponential sequence can be accomplished. However, the models derived from dx(1)/dt+ax(1) =b are only close to those derived from x(0)(k)+az(1)(k)=b provided that|a|has to satisfy|a| < 0.1; neither could the unbiased simulation for the homoge-neous exponential sequence be achieved. The above conclusions are proved and verified through some theorems and examples.

  8. Grey Energy: new standards; Der Normersatz

    Energy Technology Data Exchange (ETDEWEB)

    Gugerli, H.; Frischknecht, R.; Kasser, U.; Lenzlinger, M.

    2009-07-01

    This article takes a look at new standards that are relevant to grey energy - i.e. that energy which is embodied in a product. A new leaflet issued by the Swiss Association of Engineers and Architects SIA is examined and its stipulations are discussed. Developments in the area of energy balances and, in particular, the growing importance of taking grey energy into account are discussed. System boundaries and data sources are examined and the importance of grey energy balances in architectural competitions is noted. The energy demands of a building in the course of its lifetime are schematically illustrated in a diagram and recommendations are made for work to be done in the various phases of a project. Data, calculations and typical values are discussed and possible simplifications that can be made during calculation activities are noted.

  9. Novel grey forecast model and its application

    Institute of Scientific and Technical Information of China (English)

    丁洪发; 舒双焰; 段献忠

    2003-01-01

    The advancement of grey system theory provides an effective analytic tool for power system load fore-cast. All kinds of presently available grey forecast models can be well used to deal with the short-term load fore-cast. However, they make big errors for medium or long-term load forecasts, and the load that does not satisfythe approximate exponential increasing law in particular. A novel grey forecast model that is capable of distin-guishing the increasing law of load is adopted to forecast electric power consumption (EPC) of Shanghai. Theresults show that this model can be used to greatly improve the forecast precision of EPC for a secondary industryor the whole society.

  10. Spectral quasi-linearisation method for nonlinear thermal convection flow of a micropolar fluid under convective boundary condition

    Science.gov (United States)

    RamReddy, Ch.; Pradeepa, T.

    2016-09-01

    The significance of nonlinear temperaturedependent density relation and convective boundary condition on natural convection flow of an incompressible micropolar fluid with homogeneous-heterogeneous reactions is analyzed. In spite of the complicated nonlinear structure of the present setup and to allow all the essential features, the representation of similarity transformations for the system of non-dimensional fluid flow equations is attained through Lie group transformations and hence the governing similarity equations are worked out by a numerical approach known as spectral quasi-linearization method. It is noticed that in the presence of the nonlinear convection parameter enhance the velocity, species concentration, heat transfer rate, skin friction, but decreases the temperature and wall couple stress.

  11. Temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with a soft on-site potential.

    Science.gov (United States)

    Yang, Linlin; Li, Nianbei; Li, Baowen

    2014-12-01

    The temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with soft on-site potential (soft-KG) are investigated systematically. Similarly to the previously studied hard-KG lattices, the existence of renormalized phonons is also confirmed in soft-KG lattices. In particular, the temperature dependence of the renormalized phonon frequency predicted by a classical field theory is verified by detailed numerical simulations. However, the thermal conductivities of soft-KG lattices exhibit the opposite trend in temperature dependence in comparison with those of hard-KG lattices. The interesting thing is that the temperature-dependent thermal conductivities of both soft- and hard-KG lattices can be interpreted in the same framework of effective phonon theory. According to the effective phonon theory, the exponents of the power-law dependence of the thermal conductivities as a function of temperature are only determined by the exponents of the soft or hard on-site potentials. These theoretical predictions are consistently verified very well by extensive numerical simulations.

  12. Temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with a soft on-site potential

    Science.gov (United States)

    Yang, Linlin; Li, Nianbei; Li, Baowen

    2014-12-01

    The temperature-dependent thermal conductivities of one-dimensional nonlinear Klein-Gordon lattices with soft on-site potential (soft-KG) are investigated systematically. Similarly to the previously studied hard-KG lattices, the existence of renormalized phonons is also confirmed in soft-KG lattices. In particular, the temperature dependence of the renormalized phonon frequency predicted by a classical field theory is verified by detailed numerical simulations. However, the thermal conductivities of soft-KG lattices exhibit the opposite trend in temperature dependence in comparison with those of hard-KG lattices. The interesting thing is that the temperature-dependent thermal conductivities of both soft- and hard-KG lattices can be interpreted in the same framework of effective phonon theory. According to the effective phonon theory, the exponents of the power-law dependence of the thermal conductivities as a function of temperature are only determined by the exponents of the soft or hard on-site potentials. These theoretical predictions are consistently verified very well by extensive numerical simulations.

  13. Grey literature in library and information studies

    CERN Document Server

    Schopfel, Joachim

    2010-01-01

    The further rise of electronic publishing has come to change the scale and diversity of grey literature facing librarians and other information practitioners. This compiled work brings together research and authorship over the past decade dealing with both the supply and demand sides of grey literature. While this book is written with students and instructors of Colleges and Schools of Library and Information Science in mind, it likewise serves as a reader for information professionals working in any and all like knowledge-based communities

  14. Instability and noise-induced thermalization of Fermi–Pasta–Ulam recurrence in the nonlinear Schrödinger equation

    Energy Technology Data Exchange (ETDEWEB)

    Wabnitz, Stefan, E-mail: stefan.wabnitz@unibs.it [Dipartimento di Ingegneria dell' Informazione, Università degli Studi di Brescia, via Branze 38, 25123 Brescia (Italy); Wetzel, Benjamin [INRS-EMT, 1650 Blvd. Lionel-Boulet, Varennes, Québec J3X 1S2 (Canada)

    2014-07-25

    We investigate the spontaneous growth of noise that accompanies the nonlinear evolution of seeded modulation instability into Fermi–Pasta–Ulam recurrence. Results from the Floquet linear stability analysis of periodic solutions of the three-wave truncation are compared with full numerical solutions of the nonlinear Schrödinger equation. The predicted initial stage of noise growth is in a good agreement with simulations, and is expected to provide further insight into the subsequent dynamics of the field evolution after recurrence breakup.

  15. Hydromagnetic Flow over an Inclined Non-Linear Stretching Sheet with Variable Viscosity in the Presence of Thermal Radiation and Chemical Reaction

    Directory of Open Access Journals (Sweden)

    G. C. Shit

    2014-01-01

    Full Text Available An analysis has been made to investigate the effects of thermal radiation on the magnetohydrodynamic (MHD flow and heat transfer over an inclined non-linear stretching sheet. The surface velocity of the stretching sheet and the transverse magnetic field are assumed to vary as a power function of the distance from the origin. The effect of internal heat generation/absorption is taken into account. The fluid viscosity is assumed to vary as an inverse linear function of temperature. A generalized similarity transformation is used to reduce the governing partial differential equations to a system of non-linear coupled ordinary differential equations, and is solved numerically by using a finite difference scheme. The numerical results concerned with the velocity, temperature and concentration distributions as well as the skin-friction coefficient and the Nusselt number for various values of the dimensionless parameters of interest are obtained. Some important findings reported in this paper reveal that the effect of thermal radiation and heat generation/absorption have significant role in controlling the rate of heat transfer in the boundary layer region.

  16. A Non-Linear Finite Element Model for the Determination of Elastic and Thermal Properties of Nanocomposites

    Science.gov (United States)

    2009-04-01

    methods of better aligning nanotubes in a composite. The methods of electrospinning , magnetic field inducing, liquid crystal inducing, shear flow...reported to have constant values of thermal conductivity. Xu et HP al. [47] reported a constant thermal conductivity of - 0.2 —•—for their PVDF polymer

  17. Application of entropy measurement technique in grey based ...

    African Journals Online (AJOL)

    characteristic of the MIG welding, grey relational analysis coupled with entropy .... This process is known as grey relational generation (Tosun, 2006; Tsao, 2009). ...... Tusek J., Kampus Z. and Suban M., 2001, Welding of tailored blank of ...

  18. Tularemia without lesions in grey tree squirrels: A diagnostic challenge

    Science.gov (United States)

    Fifteen cases of Francisella tularenesis infection (tularemia) were identified in western grey (Sciurus griseus) and eastern grey (Sciurus carolinesis) squirrels submitted to the Washington Animal Disease Diagnostic Laboratory between 2008 and 2011. All of the squirrels originated in Washington stat...

  19. Comments on: “Crystal growth and comparison of vibrational and thermal properties of semi-organic nonlinear optical materials”

    Indian Academy of Sciences (India)

    Srinivasan Bikshandarkoil R; Fernandes Royle

    2016-03-01

    In {\\it Pramana – J. Phys. } 75, 683 (2010), Gunasekaran et al reported that they have grown the nonlinear optical crystals, urea thiourea mercuric chloride (UTHC) and urea thiourea mercuric sulphate (UTHS).We argue that UTHC and UTHS are dubious crystals and are not what the authors propose.

  20. Grey matter atrophy in patients suffering from multiple sclerosis.

    Science.gov (United States)

    Kincses, Zsigmond Tamás; Tóth, Eszter; Bankó, Nóra; Veréb, Dániel; Szabó, Nikoletta; Csete, Gergő; Faragó, Péter; Király, András; Bencsik, Krisztina; Vécsei, László

    2014-09-30

    White matter lesions are defining characteristics of multiple sclerosis (MS), whereas grey matter involvement is a less recognised attribute. Recent investigations using dedicated imaging approaches have made it possible to depict cortical lesions. Additionally, grey matter atrophy may be estimated using various methods. Several studies have suggested that grey matter atrophy closely correlates to clinical disability. In this review we have collected information on grey matter atrophy in MS and the effect of disease modifying therapies upon brain atrophy.

  1. Grey Documentation as a Knowledge Base in Social Work.

    Science.gov (United States)

    Berman, Yitzhak

    1994-01-01

    Defines grey documentation as documents issued informally and not available through normal channels and discusses the role that grey documentation can play in the social work knowledge base. Topics addressed include grey documentation and science; social work and the empirical approach in knowledge development; and dissemination of grey…

  2. Searching for Grey Literature for Systematic Reviews: Challenges and Benefits

    Science.gov (United States)

    Mahood, Quenby; Van Eerd, Dwayne; Irvin, Emma

    2014-01-01

    There is ongoing interest in including grey literature in systematic reviews. Including grey literature can broaden the scope to more relevant studies, thereby providing a more complete view of available evidence. Searching for grey literature can be challenging despite greater access through the Internet, search engines and online bibliographic…

  3. Grey Model of the Investment Portfolio Optimization

    Institute of Scientific and Technical Information of China (English)

    LI Qun

    2002-01-01

    The theory of investment portfolio is a very important theory in the modern economical system.Based on the feature of the theory, the paper sets up new various kinds of models of investment portfolio,namely grey optimization models. These models are more practical and objective to existing problems.

  4. Ethnographies of Grey Zones in Eastern Europe

    DEFF Research Database (Denmark)

    ’ and internationally minded ‘new citizens’ has left some in poverty, unemployment and social insecurity, leading them to rely on normative coping and semi-autonomous strategies for security and social guarantees. This anthology explores how grey zones of governance, borders, relations and invisibilities affect...

  5. Incoherently Coupled Grey Photovoltaic Spatial Soliton Families

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-Cheng; SHE Wei-Long

    2005-01-01

    @@ A theory is developed for incoherently coupled grey photovoltaic soliton families in unbiased photovoltaic crystals.Both the properties and the forming conditions of these soliton families are discussed in detail The theory canalso be used to investigate the dark photovoltaic soliton families. Some relevant examples are presented, in which the photovoltaic-photorefractive crystal is of lithium niobate type.

  6. Towards a continuum of scholarship : the eventual collapse of the distinction between grey and non-grey literature

    OpenAIRE

    Marcus A. Banks

    2005-01-01

    This paper argues that the distinction between grey and non-grey (or white) literature will become less relevant over time, as online discovery options proliferate. In the meantime, the political success of the open access publishing movement has valuable lessons for proponents of increasing access to grey literature.

  7. Nonlinear resonance converse magnetoelectric effect modulated by voltage for the symmetrical magnetoelectric laminates under magnetic and thermal loadings

    Science.gov (United States)

    Zhou, Hao-Miao; Liu, Hui; Zhou, Yun; Hu, Wen-Wen

    2016-12-01

    Based on the tri-layer symmetrical magnetoelectric laminates, a equivalent circuit for the nonlinear resonance converse magnetoelectric coupling effect is established. Because the nonlinear thermo-magneto-mechanical constitutive equations of magnetostrictive material were introduced, a converse magnetoelectric coefficient model was derived from the equivalent circuit, which can describe the influence of bias electric field, bias magnetic field and ambient temperature on the resonance converse magnetoelectric coupling effect. Especially, the model can well predict the modulation effect of bias electric field/voltage on the magnetism of magnetoelectric composite or the converse magnetoelectric coefficient, which is absolutely vital in applications. Both of the converse magnetoelectric coefficient and the resonance frequency predicted by the model have good agreements with the existing experimental results in qualitatively and quantitatively, and the validity of the model is confirmed. On this basis, according to the model, the nonlinear trends of the resonance converse magnetoelectric effect under different bias voltages, bias magnetic fields and ambient temperatures are predicted. From the results, it can be found that the bias voltage can effectively modulate the curve of the resonance converse magnetoelectric coefficient versus bias magnetic field, and then change the corresponding optimal bias magnetic field of the maximum converse magnetoelectric coefficient; with the increasing volume ratio of piezoelectric layers, the modulation effect of bias voltage becomes more obvious; under different bias magnetic fields, the modulation effect of bias voltage on the converse magnetoelectric effect has nonvolatility in a wide temperature region.

  8. Evaluation of appropriate technologies for grey water treatments and reuses.

    Science.gov (United States)

    Li, Fangyue; Wichmann, Knut; Otterpohl, Ralf

    2009-01-01

    As water is becoming a rare resource, the onsite reuse and recycling of grey water is practiced in many countries as a sustainable solution to reduce the overall urban water demand. However, the lack of appropriate water quality standards or guidelines has hampered the appropriate grey water reuses. Based on literature review, a non-potable urban grey water treatment and reuse scheme is proposed and the treatment alternatives for grey water reuse are evaluated according to the grey water characteristics, the proposed standards and economical feasibility.

  9. Distribution Inventory Cost Optimization Under Grey and Fuzzy Uncertainty

    Institute of Scientific and Technical Information of China (English)

    LIU Dongbo; HUANG Dao; CHEN Yujuan

    2006-01-01

    The grey fuzzy variable was defined for the two fold uncertain parameters combining grey and fuzziness factors. On the basis of the credibility and chance measure of grey fuzzy variables, the distribution center inventory uncertain programming model was presented. The grey fuzzy simulation technology can generate input-output data for the uncertain functions. The neural network trained from the input-output data can approximate the uncertain functions. The designed hybrid intelligent algorithm by embedding the trained neural network into genetic algorithm can optimize the general grey fuzzy programming problems. Finally, one numerical example is provided to illustrate the effectiveness of the model and the hybrid intelligent algorithm.

  10. Efficient Parameterization for Grey-box Model Identification of Complex Physical Systems

    DEFF Research Database (Denmark)

    Blanke, Mogens; Knudsen, Morten Haack

    2006-01-01

    Grey box model identification preserves known physical structures in a model but with limits to the possible excitation, all parameters are rarely identifiable, and different parametrizations give significantly different model quality. Convenient methods to show which parameterizations are the be...... that need be constrained to achieve satisfactory convergence. Identification of nonlinear models for a ship illustrate the concept.......Grey box model identification preserves known physical structures in a model but with limits to the possible excitation, all parameters are rarely identifiable, and different parametrizations give significantly different model quality. Convenient methods to show which parameterizations...... are the better would be very useful. This paper shows how we can assess the parameter interdependence and model quality. Hessian matrix decomposition is employed to show linear dependencies between variables and to put a quality tag on different parameterizations. The method determines parameter relations...

  11. Studies on the growth aspects, structural, thermal, dielectric and third order nonlinear optical properties of solution grown 4-methylpyridinium p-nitrophenolate single crystal

    Science.gov (United States)

    Devi, S. Reena; Kalaiyarasi, S.; Zahid, I. MD.; Kumar, R. Mohan

    2016-11-01

    An ionic organic optical crystal of 4-methylpyridinium p-nitrophenolate was grown from methanol by slow evaporation method at ambient temperature. Powder and single crystal X-ray diffraction studies revealed the crystal system and its crystalline perfection. The rocking curve recorded from HRXRD study confirmed the crystal quality. FTIR spectral analysis confirmed the functional groups present in the title compound. UV-visible spectral study revealed the optical window and band gap of grown crystal. The thermal, electrical and surface laser damage threshold properties of harvested crystal were examined by using TGA/DTA, LCR/Impedance Analyzer and Nd:YAG laser system respectively. The third order nonlinear optical property of grown crystal was elucidated by Z-scan technique.

  12. A bistriphenylamine-substituted spirobifluorene derivative exhibiting excellent nonlinearity/transparency/thermal stability trade-off and strong two-photon induced blue fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Hongyao [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China); Xiao, Haibo, E-mail: xiaohb@shnu.edu.cn [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China); Ding, Lei [Department of Chemistry, Shanghai Normal University, Shanghai 200234 (China); Zhang, Chun; Ren, Aiming [State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023 (China); Li, Bo [Key Laboratory of Polar Materials and Devices, Ministry of Education, East China Normal University, Shanghai 200241 (China)

    2015-02-01

    A spirobifluorene-bridged donor/donor chromophore, 2,7-bis-(4-(N,N-diphenylamino)phen-1-yl)-9,9′-spirobifluorene (SPF-TP), was found to combine excellent transparency in the near UV–visible region (λ{sub cut-off} ≤ 420 nm), large two-photon absorption cross-section (4.5 × 10{sup 3}GM) and high thermal stability (T{sub d} = 501 °C). In comparison to the reported two-photon absorption molecules, SPF-TP represents the best thermal stability so far described in the literature. The main electronic factors explaining the high two-photon absorption activities of SPF-TP were analyzed by theoretical calculations. Cyclic voltammograms were employed to explore the causes of the excellent transparency of SPF-TP. It was found that the spiroconjugation effect is responsible for the excellent nonlinearity/transparency/thermal stability trade-off in SPF-TP. In addition, SPF-TP is also a good two-photon induced blue fluorescent material with high fluorescence quantum yield (Φ = 0.90, in THF). - Highlights: • We report a molecule exhibiting excellent transparency. • The two-photon absorption cross-section is as large as 4.5 × 10{sup 3}GM. • The molecule exhibits excellent thermal stability. • The molecule is a good two-photon induced blue fluorescent material. • The spiroconjugation effect explains the excellent properties.

  13. Nonlinear Effects in Piezoelectric Transformers Explained by Thermal-Electric Model Based on a Hypothesis of Self-Heating

    DEFF Research Database (Denmark)

    Andersen, Thomas; Andersen, Michael A. E.; Thomsen, Ole Cornelius;

    2012-01-01

    As the trend within power electronic still goes in the direction of higher power density and higher efficiency, it is necessary to develop new topologies and push the limit for the existing technology. Piezoelectric transformers are a fast developing technology to improve efficiency and increase...... power density of power converters. Nonlinearities in piezoelectric transformers occur when the power density is increased enough. The simple linear equations are not valid at this point and more complex theory of electro elasticity must be applied. In This work a simplified thermo-electric model...

  14. Crystal structure, optical and thermal studies of a new organic nonlinear optical material: L-Histidinium maleate 1.5-hydrate

    Energy Technology Data Exchange (ETDEWEB)

    Gonsago, C. Alosious [Department of Physics, A. J. College of Engineering, Chennai 603103 (India); Albert, Helen Merina [Department of Physics, Sathyabama University, Chennai 600119 (India); Karthikeyan, J. [Department of Chemistry, Sathyabama University, Chennai 600119 (India); Sagayaraj, P. [Department of Physics, Loyola College, Chennai 600034 (India); Pragasam, A. Joseph Arul, E-mail: drjosephsu@gmail.com [Department of Physics, Sathyabama University, Chennai 600119 (India)

    2012-07-15

    Highlights: ► L-Histidinium maleate 1.5-hydrate, a new organic crystal has been grown for the first time. ► The crystal structure is reported for the first time (CCDC 845975). ► The crystal belongs to monoclinic system with space group P2{sub 1}, Z = 4, a = 11.4656(7) Å, b = 8.0530(5) Å, c = 14.9705(9) Å and β = 101.657(2)°. ► The optical absorption study substantiates the complete transparency of the crystal. ► Kurtz powder SHG test confirms the nonlinear property of the crystal. -- Abstract: A new organic nonlinear optical material L-histidinium maleate 1.5-hydrate (LHM) with the molecular formula C{sub 10}H{sub 16}N{sub 3}O{sub 7.5} has been successfully synthesized from aqueous solution by slow solvent evaporation method. The structural characterization of the grown crystal was carried out by single crystal X-ray diffraction at 293(2) K. In the crystal, molecules are linked through inter and intramolecular N-H⋯O and O-H⋯O hydrogen bonds, generate edge fused ring motif. The hydrogen bonded motifs are linked to each other to form a three dimensional network. The FT-IR spectroscopy was used to identify the functional groups of the synthesized compound. The optical behavior of the grown crystal was examined by UV–visible spectral analysis, which shows that the optical absorption is almost negligible in the wavelength range 280–1300 nm. The nonlinear optical property was confirmed by the powder technique of Kurtz and Perry. The thermal behavior of the grown crystal was analyzed by thermogravimetric analysis.

  15. Growth, structural, optical, thermal and dielectric properties of a novel semi-organic nonlinear optical crystal:Dichloro-diglycine zinc II

    Institute of Scientific and Technical Information of China (English)

    B. Uma; Rajnikant; K. Sakthi Murugesan; S. Krishnan; B. Milton Boaz

    2014-01-01

    Dichloro-diglycine zinc II (DCDGZ II), a semi-organic nonlinear optical material has been synthesized and single crystals were grown from the aqueous solution up to dimensions 20 × 10 × 3 mm3. The title compound, DCDGZ II (C4H10Cl2N2O4Zn ÁH2O) crystallizes into monoclinic structure with the space group of C2/c. The unit-cell parameters were found to be a=14.4191(7), b=6.9180(2), c=12.9452(6) Å and Z=4. In the crystal structure, DCDGZ II layer is building up alternatingly with layers of water in which the zinc ions lie on a twofold axis. Theoretical calculations for polarizability, which are useful for device fabrication were made using Clausius-Mosotti equation and Penn analysis and the results were compared. Fourier transform infrared (FTIR) spectroscopic studies were performed for the identification of the different functional groups presented in the compound. The UV-vis-NIR absorption spectrum reveals that the lower UV cut-off wavelength is 240 nm. The optical band gap of the crystal was estimated as 2.2 eV. The surface morphology, thermal behaviour, dielectric properties have been studied using SEM, TG/DTA and LCR HITESTER analyzer. The nonlinear optical property of the crystal was also confirmed using Kurtz powder technique.

  16. Growth, structural, optical, thermal and dielectric properties of a novel semi-organic nonlinear optical crystal: Dichloro-diglycine zinc II

    Directory of Open Access Journals (Sweden)

    B. Uma

    2014-08-01

    Full Text Available Dichloro-diglycine zinc II (DCDGZ II, a semi-organic nonlinear optical material has been synthesized and single crystals were grown from the aqueous solution up to dimensions 20×10×3 mm3. The title compound, DCDGZ II (C4H10Cl2N2O4Zn·H2O crystallizes into monoclinic structure with the space group of C2/c. The unit-cell parameters were found to be a=14.4191(7, b=6.9180(2, c=12.9452(6 Å and Z=4. In the crystal structure, DCDGZ II layer is building up alternatingly with layers of water in which the zinc ions lie on a twofold axis. Theoretical calculations for polarizability, which are useful for device fabrication were made using Clausius–Mosotti equation and Penn analysis and the results were compared. Fourier transform infrared (FTIR spectroscopic studies were performed for the identification of the different functional groups presented in the compound. The UV–vis–NIR absorption spectrum reveals that the lower UV cut-off wavelength is 240 nm. The optical band gap of the crystal was estimated as 2.2 eV. The surface morphology, thermal behaviour, dielectric properties have been studied using SEM, TG/DTA and LCR HITESTER analyzer. The nonlinear optical property of the crystal was also confirmed using Kurtz powder technique.

  17. Grey Box Modelling of Hydrological Systems

    DEFF Research Database (Denmark)

    Thordarson, Fannar Ørn

    The main topic of the thesis is grey box modelling of hydrologic systems, as well as formulation and assessment of their embedded uncertainties. Grey box model is a combination of a white box model, a physically-based model that is traditionally formulated using deterministic ordinary differential...... the lack of fit in state space formulation, and further support decisions for a model expansion. By using stochastic differential equations to formulate the dynamics of the hydrological system, either the complexity of the model can be increased by including the necessary hydrological processes...... in the model, or formulation of process noise can be considered so that it meets the physical limits of the hydrological system and give an adequate description of the embedded uncertainty in model structure. The thesis consists of two parts: a summary report and a part which contains six scientific papers...

  18. Grey-theory based intrusion detection model

    Institute of Scientific and Technical Information of China (English)

    Qin Boping; Zhou Xianwei; Yang Jun; Song Cunyi

    2006-01-01

    To solve the problem that current intrusion detection model needs large-scale data in formulating the model in real-time use, an intrusion detection system model based on grey theory (GTIDS) is presented. Grey theory has merits of fewer requirements on original data scale, less limitation of the distribution pattern and simpler algorithm in modeling.With these merits GTIDS constructs model according to partial time sequence for rapid detect on intrusive act in secure system. In this detection model rate of false drop and false retrieval are effectively reduced through twice modeling and repeated detect on target data. Furthermore, GTIDS framework and specific process of modeling algorithm are presented. The affectivity of GTIDS is proved through emulated experiments comparing snort and next-generation intrusion detection expert system (NIDES) in SRI international.

  19. Making Grey Literature Available through Institutional Repositories

    OpenAIRE

    Rupp, Nathan; LaFleur, Lee J. (Cornell University); GreyNet, Grey Literature Network Service

    2004-01-01

    One of the major components of grey literature is conference proceedings. A major purpose of conferences is to disseminate research in a particular area, and this is often done through conference proceedings. However, although many libraries collect conference proceedings, they collect them mostly in print. With the advent of digital library collections—electronic journals, digital library projects, etc.—conference proceedings have been neglected. Even though the research in conference procee...

  20. The Basic Analysis of Dorian Grey

    Institute of Scientific and Technical Information of China (English)

    骆应吉

    2015-01-01

    Oscar Wild is a famous poet,author and playwright who has also been a sponsor of the aestheticism in Victoria time he lives.I will analyze the main point of Wild’s idea reflected in this novel according to the personal analysis of the three major men in this novel:Dorian Grey.Inevitably when we study Wild and his work

  1. The Basic Analysis of Dorian Grey

    Institute of Scientific and Technical Information of China (English)

    骆应吉

    2015-01-01

    Oscar Wild is a famous poet,author and playwright who has also been a sponsor of the aestheticism in Victoria time he lives.I will analyze the main point of Wild’s idea reflected in this novel according to the personal analysis of the three major men in this novel:Dorian Grey.Inevitably when we study Wild and his work.

  2. Crystal growth, structural, spectral, thermal, linear and nonlinear optical characterization of a new organic nonlinear chiral compound: L-tryptophan-fumaric acid-water (1/1/1) suitable for laser frequency conversion

    Science.gov (United States)

    Peer Mohamed, M.; Jayaprakash, P.; Nageshwari, M.; Rathika Thaya Kumari, C.; Sangeetha, P.; Sudha, S.; Mani, G.; Lydia Caroline, M.

    2017-08-01

    A new organic active nonlinear optical crystal L-tryptophan fumaric acid water (1/1/1), (C15H17N2 O7. H2O)(LTFAW), consisting of zwitterion tryptophan molecule in conjunction with a fumaric acid molecule and a water molecule was grown by slow solvent evaporation technique from aqueous solution. The organic chromophore crystallizes from water in its zwitterions exhibiting tabular habit in monoclinic system with acentric space group C2 (Z = 4). The sharp peaks observed in Powder X-ray diffractogram depicts the crystalline nature. The presence of functional groups in the grown crystal was analyzed using FT-IR spectrum. The carbon and hydrogen environment in molecular structure was investigated using FT-NMR technique using deuterated DMSO solution. Ultraviolet-visible spectral analysis reveal that the crystal possess lower cut-off wavelength down to 275 nm, is a key factor to exhibit Second Harmonic Generation (SHG) signal. The direct optical band gap is evaluated to be 5.28 eV from the UV absorption profile. The evaluation of optical constants by employing UV-visible absorbance data such as, extinction coefficient, reflectance, refractive index, optical conductivity are supportive towards good performance as NLO devices. Temperature of decomposition was investigated using thermogravimetric analysis/differential thermal analysis techniques (TG/DTA). The luminescence profile exhibited two peaks (362 nm, 683 nm) due to the donation of protons from carboxylic group to amino group. The nonlinear optical behavior from the noncentrosymmetric crystal was observed by the generation of frequency doubled (2ω) optical radiation when subjected to pulsed Nd:YAG laser (1064 nm, 10 ns, 10 Hz) using Kurtz-Perry method. The variation of dielectric constant (εʹ) and dielectric loss (εʹʹ) vs. Log f for the title compound was analysed at a few selected temperatures and frequencies.

  3. Linear and nonlinear obliquely propagating ion-acoustic waves in magnetized negative ion plasma with non-thermal electrons

    Science.gov (United States)

    Mishra, M. K.; Jain, S. K.; Jain

    2013-10-01

    Ion-acoustic solitons in magnetized low-β plasma consisting of warm adiabatic positive and negative ions and non-thermal electrons have been studied. The reductive perturbation method is used to derive the Korteweg-de Vries (KdV) equation for the system, which admits an obliquely propagating soliton solution. It is found that due to the presence of finite ion temperature there exist two modes of propagation, namely fast and slow ion-acoustic modes. In the case of slow-mode if the ratio of temperature to mass of positive ion species is lower (higher) than the negative ion species, then there exist compressive (rarefactive) ion-acoustic solitons. It is also found that in the case of slow mode, on increasing the non-thermal parameter (γ) the amplitude of the compressive (rarefactive) soliton decreases (increases). In fast ion-acoustic mode the nature and characteristics of solitons depend on negative ion concentration. Numerical investigation in case of fast mode reveals that on increasing γ, the amplitude of compressive (rarefactive) soliton increases (decreases). The width of solitons increases with an increase in non-thermal parameters in both the modes for compressive as well as rarefactive solitons. There exists a value of critical negative ion concentration (α c ), at which both compressive and rarefactive ion-acoustic solitons appear as described by modified KdV soliton. The value of α c decreases with increase in γ.

  4. Structural, optical, thermal and mechanical characterization of an organic nonlinear optical material: 4-methyl-3-nitrobenzoic acid single crystal

    Science.gov (United States)

    Bharathi, M. Divya; Ahila, G.; Mohana, J.; Chakkaravarthi, G.; Anbalagan, G.

    2016-11-01

    Organic single crystals of 4-methyl-3-nitrobenzoic acid (4M3N) have been grown by slow evaporation solution growth technique at room temperature. The single crystal X-ray diffraction study reveals that 4M3N crystallizes in monoclinic system with space group P21/n. The crystalline perfection of the crystal was analyzed by high resolution X-ray diffraction (HRXRD) measurements. The functional groups present in 4M3N have been identified from FT-IR and FT-Raman spectra. The lower cut-off wavelength of 4M3N is found to be 404 nm and the optical band gap is calculated as 2.91 eV. The refractive index shows normal behavior with wavelength. The physio chemical changes, decomposition and stability of the 4M3N compound were established by TG-DTA studies. Vickers microhardness measurement concludes that 4M3N belongs to soft material (n=2.5) category. The LDT value is found to be higher than that of KDP and some of the important organic NLO materials. The third order nonlinear refractive index and nonlinear absorption coefficient of the 4M3N have been measured by Z-scan studies. The imaginary and real parts of the third-order susceptibility values were determined as Im χ3=9.129×10-11 esu and Re χ3=1.4034×10-9 esu respectively. The dislocation density was calculated to be 3.0448×106 cm-2 which indicates the quality of the crystal.

  5. Phase matching, X-Ray topography, optical and thermal analysis of L-alanine cadmium chloride monohydrate: a nonlinear optical material

    Science.gov (United States)

    Krishna, Anuj; Vijayan, N.; Riscob, B.; Gour, B. S.; Haranath, D.; Philip, J.; Verma, S.; Jayalakshmy, M. S.; Bhagavannarayana, G.; Halder, S. K.

    2014-03-01

    A potential semiorganic nonlinear optical material, L-alanine cadmium chloride monohydrate has been successfully synthesised and single crystals have been grown by slow evaporation solution growth technique at room temperature by using double distilled water as the solvent. The lattice dimensions of the grown crystal have been analysed by adopting powder X-ray diffraction technique and found that it crystallised in monoclinic system with space group C2. The crystalline perfection of the as-grown crystal has been assessed by high resolution X-ray diffraction and X-ray topography techniques and observed that the quality of the grown specimen is reasonably good. Its optical properties were examined by UV-Vis and photoluminescence techniques and found that there is no absorption in the entire visible range. Its functional groups were identified from FT-Raman and observed that there is no incorporation of other impurities during crystallisation. Its relative second harmonic generation efficiency has been tested with different particle size by Kurtz powder technique and found that within the coherence length the title compound is phase matchable. Its various thermal properties like thermal conductivity, specific heat, thermal effusivity, etc. have been evaluated by photopyroelectric technique and compared with other organic and inorganic materials. To confirm its piezoelectric response, its piezoelectric charge coefficient was measured using piezometer and found low. Its optical homogeneity as well as birefringence measurement of the grown specimen has been carried out by interferometric technique. The surface defects of the grown LACCM single crystal were analysed with etching at room temperature using water as an etchant.

  6. Phase matching, X-Ray topography, optical and thermal analysis of L-alanine cadmium chloride monohydrate: a nonlinear optical material

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, Anuj; Vijayan, N.; Haranath, D.; Bhagavannarayana, G.; Halder, S.K. [CSIR - National Physical Laboratory, New Delhi (India); Riscob, B. [CSIR - National Physical Laboratory, New Delhi (India); Institute of Plasma Research, Bhat, Gandhinagar (India); Gour, B.S. [Rajiv Gandhi Proudyogiki Vishwavidyalaya, Bhopal (India); Philip, J.; Jayalakshmy, M.S. [Cochin University of Science and Technology, Cochin (India); Verma, S. [Raja Ramanna Centre for Advanced Technology, Laser Materials Development and Devices Division, Indore (India)

    2014-03-15

    A potential semiorganic nonlinear optical material, L-alanine cadmium chloride monohydrate has been successfully synthesised and single crystals have been grown by slow evaporation solution growth technique at room temperature by using double distilled water as the solvent. The lattice dimensions of the grown crystal have been analysed by adopting powder X-ray diffraction technique and found that it crystallised in monoclinic system with space group C2. The crystalline perfection of the as-grown crystal has been assessed by high resolution X-ray diffraction and X-ray topography techniques and observed that the quality of the grown specimen is reasonably good. Its optical properties were examined by UV-Vis and photoluminescence techniques and found that there is no absorption in the entire visible range. Its functional groups were identified from FT-Raman and observed that there is no incorporation of other impurities during crystallisation. Its relative second harmonic generation efficiency has been tested with different particle size by Kurtz powder technique and found that within the coherence length the title compound is phase matchable. Its various thermal properties like thermal conductivity, specific heat, thermal effusivity, etc. have been evaluated by photopyroelectric technique and compared with other organic and inorganic materials. To confirm its piezoelectric response, its piezoelectric charge coefficient was measured using piezometer and found low. Its optical homogeneity as well as birefringence measurement of the grown specimen has been carried out by interferometric technique. The surface defects of the grown LACCM single crystal were analysed with etching at room temperature using water as an etchant. (orig.)

  7. 基于灰关联熵分析的大掺量粉煤灰混凝土导热性能影响因素研究%Grey Correlation Entropy Method to Analyze Thermal Properties of High Volume Fly Ash Concrete

    Institute of Scientific and Technical Information of China (English)

    哈斯图雅

    2015-01-01

    为了探究各因素对大掺量粉煤灰混凝土导热性能的影响,通过试验,以导热系数为主要导热性能指标,运用灰关联熵分析的手段,定量分析了水胶比、粉煤灰掺量、减水剂掺量、砂率和骨料干湿状态对大掺量粉煤灰混凝土导热系数影响的显著程度。经计算分析得出:对大掺量粉煤灰混凝土导热性能影响最大的是砂率,其次依次为粉煤灰掺量、水胶比、减水剂掺量和骨料干湿状态。在进行大掺量粉煤灰混凝土配合比设计时,从导热性能方面考虑,必须严格控制砂率。%In order to explore the factors that influence the performance of high volume fly ash concrete heat conduction,through the test,use conductivity as the mainly thermal performance indicators, using the grey relation entropy analysis method,to analysis the effect of degree of water binder ratio,fly ash content,water reducing agent dosage,sand ratio and aggregate in dry and wet conditions to high vol-ume fly ash concrete heat conduction quantitativiy.Through calculation and analysis:the most significant factor influence on performance of high volume fly ash concrete heat conduction is sand rate,followed by the amount of fly ash,water binder ratio,dosage of water reducer and aggregate in dry and wet condi-tions.In high volume fly ash concrete mix design,considering thethermal conductivity performance,must strictly control therate of sand.

  8. Joint SFT-GUT workshop day on thermal engineering and non-linear physics; Journee d`etudes SFT-GUT sur la thermique et la physique non-lineaire

    Energy Technology Data Exchange (ETDEWEB)

    Roche, J.M.; Padet, C.; Padet, J.P. [Faculte des Sciences de Reims, 51 (France). Laboratoire de Thermomecanique

    1996-12-31

    This workshop day was jointly organized by the French society of thermal engineers (SFT) and the university group of thermal engineers (GUT). This compilation of proceedings comprises 8 papers dealing with: tendencies and ultimate tendencies of a non-linear phenomenon - scale of observation; quantification of the chaotic regime using the estimation of the information dimension; chaotic mixing and heat transfer between concentric confocal ellipses: experimental and numerical results; development of thermal instabilities in a mixed convection horizontal flow: the Lagrangian point of view; non-linear dynamics of surface instabilities: droplets and liquid columns; on the validity of global criterion when characterizing chaotic behaviour in two-dimensional flows; study of the hydrodynamical instabilities of natural convection flows in cavities partially filled with a porous medium; analytical study of induced instabilities at the nucleated ebullition - film ebullition transition. (J.S.)

  9. Grey forewarning and prediction for mine water inflowing catastrophe periods

    Institute of Scientific and Technical Information of China (English)

    MA Qi-hua; CAO Jian-jun

    2007-01-01

    Based on the theory of grey system, established GM (1, 1) grey catastrophe predict model for the first time in order to forecast the catastrophe periods of mine water inflowing (not the volume of water inflowing). After establishing the grey predict system of the catastrophe regularity of 10 month-average volume of water inflowing, the grey forewarning for mine water inflowing catastrophe periods was established which was used to analyze water disaster in -400 meter level of Wennan Colliery. Based on residual analysis,it shows that the result of grey predict system is almost close to the actual value. And the scene actual result also shows the reliability of prediction. Both the theoretical analysis and the scene actual result indicate feasibility and reliability of the method of grey catastrophe predict system.

  10. Software sensors based on the grey-box modelling approach

    DEFF Research Database (Denmark)

    Carstensen, J.; Harremoës, P.; Strube, Rune

    1996-01-01

    In recent years the grey-box modelling approach has been applied to wastewater transportation and treatment Grey-box models are characterized by the combination of deterministic and stochastic terms to form a model where all the parameters are statistically identifiable from the on......-line measurements. With respect to the development of software sensors, the grey-box models possess two important features. Firstly, the on-line measurements can be filtered according to the grey-box model in order to remove noise deriving from the measuring equipment and controlling devices. Secondly, the grey-box...... models may contain terms which can be estimated on-line by use of the models and measurements. In this paper, it is demonstrated that many storage basins in sewer systems can be used as an on-line flow measurement provided that the basin is monitored on-line with a level transmitter and that a grey-box...

  11. Academic libraries and collection development implications for grey literature

    OpenAIRE

    Gelfand, Julia; GreyNet, Grey Literature Network Service

    1994-01-01

    The proliferation of grey literature (GL) in all subject areas poses great challenges, concerns and responsibilities for libraries. This paper examines the major issues most germane to the acquisition and collection development aspects of grey literature and providing access to it in library collections. With increasing academic and scholarly value placed in the grey literature and it being an original and primary source for information, many collection development policies are beginning to i...

  12. Application of Improved Grey Prediction Model to Petroleum Cost Forecasting

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The grey theory is a multidisciplinary and generic theory that deals with systems that lack adequate information and/or have only poor information. In this paper, an improved grey model using step function was proposed.Petroleum cost forecast of the Henan oil field was used as the case study to test the efficiency and accuracy of the proposed method. According to the experimental results, the proposed method obviously could improve the prediction accuracy of the original grey model.

  13. Exploring the origins of grey matter damage in multiple sclerosis

    OpenAIRE

    Calabrese, Massimiliano; Magliozzi, Roberta; Ciccarelli, Olga; Geurts, Jeroen J. G.; Reynolds, Richard; Martin, Roland

    2015-01-01

    Multiple sclerosis is characterized at the gross pathological level by the presence of widespread focal demyelinating lesions of the myelin-rich white matter. However, it is becoming clear that grey matter is not spared, even during the earliest phases of the disease. Furthermore, grey matter damage may have an important role both in physical and cognitive disability. Grey matter pathology involves both inflammatory and neurodegenerative mechanisms, but the relationship between the two is unc...

  14. Efficient Parameterization for Grey-box Model Identification of Complex Physical Systems

    DEFF Research Database (Denmark)

    Blanke, Mogens; Knudsen, Morten

    2006-01-01

    Grey box model identification preserves known physical structures in a model but with limits to the possible excitation, all parameters are rarely identifiable, and different parametrizations give significantly different model quality. Convenient methods to show which parameterizations...... are the better would be very useful. This paper shows how we can assess the parameter interdependence and model quality. Hessian matrix decomposition is employed to show linear dependencies between variables and to put a quality tag on different parameterizations. The method determines parameter relations...... that need be constrained to achieve satisfactory convergence. Identification of nonlinear models for a ship illustrate the concept....

  15. Growth, structural, optical, thermal and mechanical properties of cytosinium hydrogen selenite: A novel nonlinear optical single crystal

    Energy Technology Data Exchange (ETDEWEB)

    Jaikumar, P. [PG & Research Department of Physics, National College (Autonomous), Tiruchirappalli, 620 001 Tamil Nadu (India); Sathiskumar, S. [Crystal Growth Laboratory, Department of Physics, Periyar EVR College (Autonomous), Tiruchirappalli, 620 023 Tamil Nadu (India); Balakrishnan, T., E-mail: balacrystalgrowth@gmail.com [Crystal Growth Laboratory, Department of Physics, Periyar EVR College (Autonomous), Tiruchirappalli, 620 023 Tamil Nadu (India); Ramamurthi, K. [Crystal Growth & Thin Film laboratory, Department of Physics & Nanotechnology, SRM University, Kattankulathur, 603 203 Kancheepuram, Tamil Nadu (India)

    2016-06-15

    Highlights: • Growth of bulk single crystals of cytosinium hydrogen selenite (CHS) is reported. • Dielectric constant of CHS is measured as a function of Frequency and temperature. • Lower cut off value of UV–vis-NIR spectrum of CHS crystal is observed at 210 nm. • Meyer’s index value of CHS crystal calculated identifies it as a soft material. • Powder SHG efficiency of CHS is about 1.5 times that of KDP crystal. - Abstract: A novel nonlinear optical single crystal of cytosinium hydrogen selenite was grown from aqueous solution of cytosinium hydrogen selenite by slow solvent evaporation method at room temperature. The structural properties of grown crystal have been studied by single crystal and powder X-ray diffraction analysis. Presence of various functional groups was identified from Fourier transform infrared spectroscopy. The optical transmittance and absorbance spectra were recorded by UV–vis-NIR spectrometer and the grown crystal possesses good transparency in the entire visible region. The dielectric constant and dielectric loss of the crystal were calculated as a function of frequency at different temperatures. The mechanical strength of the cytosinium hydrogen selenite crystal was estimated using Vicker’s microhardness tester. Etch patterns of the cytosinium hydrogen selenite crystal were obtained using distilled water as etchant for different etching time. Second harmonic generation efficiency tested using Nd:YAG laser is about 1.5 times that of KDP.

  16. Evaluation of the heat transfer module (FAHT) of Failure Analysis Nonlinear Thermal And Structural Integrated Code (FANTASTIC)

    Science.gov (United States)

    Keyhani, Majid

    1989-01-01

    The heat transfer module of FANTASTIC Code (FAHT) is studied and evaluated to the extend possible during the ten weeks duration of this project. A brief background of the previous studies is given and the governing equations as modeled in FAHT are discussed. FAHT's capabilities and limitations based on these equations and its coding methodology are explained in detail. It is established that with improper choice of element size and time step FAHT's temperature field prediction at some nodes will be below the initial condition. The source of this unrealistic temperature prediction is identified and a procedure is proposed for avoiding this phenomenon. It is further shown that the proposed procedure will converge to an accurate prediction upon mesh refinement. Unfortunately due to lack of time FAHT's ability to accurately account for pyrolysis and surface ablation has not been verified. Therefore, at the present time it can be stated with confidence that FAHT can accurately predict the temperature field for a transient multi-dimensional, orthotropic material with directional dependence, variable property, with nonlinear boundary condition. Such a prediction will provide an upper limit for the temperature field in an ablating decomposing nozzle liner. The pore pressure field, however, will not be known.

  17. Grey Disorder in Field Flue—Cured Tobacco

    Institute of Scientific and Technical Information of China (English)

    ZHANGXIN; ZHAOQIBO; 等

    1999-01-01

    A field study was carried out on the grey disorder in flue-cured tobacco( Nicotiana tabacum L.) leaves.The results showed that low Eh and high available Fe content in the soils were responsible for the grey tobacco and dead roots.Grey disorder leaves produced low quality lamina,which was low in N,nicotine,reduced sugar and K contents,In this study,soil available Mn and leaf Mn contents were in a relatively low level and should not be an important factor in the occurrence of grey disorder in flue-cured tobacco.

  18. Exploring the origins of grey matter damage in multiple sclerosis.

    Science.gov (United States)

    Calabrese, Massimiliano; Magliozzi, Roberta; Ciccarelli, Olga; Geurts, Jeroen J G; Reynolds, Richard; Martin, Roland

    2015-03-01

    Multiple sclerosis is characterized at the gross pathological level by the presence of widespread focal demyelinating lesions of the myelin-rich white matter. However, it is becoming clear that grey matter is not spared, even during the earliest phases of the disease. Furthermore, grey matter damage may have an important role both in physical and cognitive disability. Grey matter pathology involves both inflammatory and neurodegenerative mechanisms, but the relationship between the two is unclear. Histological, immunological and neuroimaging studies have provided new insight in this rapidly expanding field, and form the basis of the most recent hypotheses on the pathogenesis of grey matter damage.

  19. Searching for grey literature for systematic reviews: challenges and benefits.

    Science.gov (United States)

    Mahood, Quenby; Van Eerd, Dwayne; Irvin, Emma

    2014-09-01

    There is ongoing interest in including grey literature in systematic reviews. Including grey literature can broaden the scope to more relevant studies, thereby providing a more complete view of available evidence. Searching for grey literature can be challenging despite greater access through the Internet, search engines and online bibliographic databases. There are a number of publications that list sources for finding grey literature in systematic reviews. However, there is scant information about how searches for grey literature are executed and how it is included in the review process. This level of detail is important to ensure that reviews follow explicit methodology to be systematic, transparent and reproducible. The purpose of this paper is to provide a detailed account of one systematic review team's experience in searching for grey literature and including it throughout the review. We provide a brief overview of grey literature before describing our search and review approach. We also discuss the benefits and challenges of including grey literature in our systematic review, as well as the strengths and limitations to our approach. Detailed information about incorporating grey literature in reviews is important in advancing methodology as review teams adapt and build upon the approaches described.

  20. Synthesis, growth, structural, spectral, thermal and microhardness studies of a new hydrogen bonded organic nonlinear optical material: L-valinium p-toluenesulfonate monohydrate (LVPT)

    Science.gov (United States)

    Suresh, M.; Bahadur, S. Asath; Athimoolam, S.

    2016-05-01

    A new organic hydrogen bonded material, L-valinium p-toluenesulfonate monohydrate (LVPT), was synthesized and grown as a single crystal by slow evaporation solution growth technique with the dimension of 29 × 7 × 4 mm3. A good X-ray quality single crystal was selected from the grown crop and used for single crystal diffraction study. It reveals that the compound crystallized in a non-centrosymmetric monoclinic space group P21 with two set of molecules in unit cell. The plane of the carboxyl group of the cation is making dihedral angle of 85.4(1)° with the plane of the aromatic ring of the anion. The crystal packing features intricate three dimensional hydrogen bonding network through chain and ring motifs. These hydrogen bonded motifs are observed at x = 0 or 1 and aromatic rings of the cations are stacked at x = 1/2 leading to alternate hydrophilic and hydrophobic layers, respectively, along a-axis of the unit cell. Fourier transform infrared (FTIR) and Raman (FT-Raman) spectral studies have been performed to identify the functional groups. The optical transmittance and the lower cutoff wavelength of the LVPT have been identified by UV-Vis absorption studies. Second harmonic generation test using a laser with wavelength of 1064 nm confirms the nonlinear optical efficiency of the sample as 1.5 greater than KDP. The thermal and mechanical properties of the sample were examined by TG/DTA and Vicker's microhardness tests, respectively. Further, the solid state properties were calculated and found to be better than the known nonlinear optical material KDP.

  1. Synthesis, structural, optical, thermal and dielectric studies on new organic nonlinear optical crystal by solution growth technique.

    Science.gov (United States)

    Prakash, M; Geetha, D; Lydia Caroline, M

    2013-04-15

    Single crystals of L-phenylalanine-benzoic acid (LPBA) were successfully grown from aqueous solution by solvent evaporation technique. Purity of the crystals was increased by the method of recrystallization. The XRD analysis confirms that the crystal belongs to the monoclinic system with noncentrosymmetric space group P21. The chemical structure of compound was established by FT-NMR technique. The presence of functional groups was estimated qualitatively by Fourier transform infrared analysis (FT-IR). Ultraviolet-visible spectral analyses showed that the crystal has low UV cut-off at 254 nm combined with very good transparency of 90% in a wide range. The optical band gap was estimated to be 6.91 eV. Thermal behavior has been studied with TGA/DTA analyses. The existence of second harmonic generation (SHG) efficiency was found to be 0.56 times the value of KDP. The dielectric behavior of the sample was also studied for the first time.

  2. Personnel selection with grey relational analysis

    Directory of Open Access Journals (Sweden)

    Nilsen Kundakcı

    2016-05-01

    Full Text Available Selection of the qualified and the most appropriate employee plays crucial role for the success of the businesses. The selection process is complex and contains both subjective and objective criteria to be considered. For this reason, in this paper, Grey Relational Analysis (GRA is proposed for employee selection. To illustrate the applicability of the proposed method, the most appropriate software engineer is selected for a technology firm. By this way, a scientific multi criteria decision making (MCDM method is proposed to the firm that determines the best candidate intuitively with traditional methods.

  3. Grey('s) Identity: Complications of Learning and Becoming in a Popular Television Show

    Science.gov (United States)

    Jubas, Kaela

    2013-01-01

    In this article, the author outlines an analysis of the American show "Grey's Anatomy" as an example of how popular culture represents identity and the process of professional identity construction in a medical workplace, particularly the surgical service of a large urban hospital. In discussing identity, she connects professional identity to…

  4. In-Flight Aeroelastic Stability of the Thermal Protection System on the NASA HIAD, Part II: Nonlinear Theory and Extended Aerodynamics

    Science.gov (United States)

    Goldman, Benjamin D.; Dowell, Earl H.; Scott, Robert C.

    2015-01-01

    Conical shell theory and a supersonic potential flow aerodynamic theory are used to study the nonlinear pressure buckling and aeroelastic limit cycle behavior of the thermal protection system for NASA's Hypersonic Inflatable Aerodynamic Decelerator. The structural model of the thermal protection system consists of an orthotropic conical shell of the Donnell type, resting on several circumferential elastic supports. Classical Piston Theory is used initially for the aerodynamic pressure, but was found to be insufficient at low supersonic Mach numbers. Transform methods are applied to the convected wave equation for potential flow, and a time-dependent aerodynamic pressure correction factor is obtained. The Lagrangian of the shell system is formulated in terms of the generalized coordinates for all displacements and the Rayleigh-Ritz method is used to derive the governing differential-algebraic equations of motion. Aeroelastic limit cycle oscillations and buckling deformations are calculated in the time domain using a Runge-Kutta method in MATLAB. Three conical shell geometries were considered in the present analysis: a 3-meter diameter 70 deg. cone, a 3.7-meter 70 deg. cone, and a 6-meter diameter 70 deg. cone. The 6-meter configuration was loaded statically and the results were compared with an experimental load test of a 6-meter HIAD. Though agreement between theoretical and experimental strains was poor, the circumferential wrinkling phenomena observed during the experiments was captured by the theory and axial deformations were qualitatively similar in shape. With Piston Theory aerodynamics, the nonlinear flutter dynamic pressures of the 3-meter configuration were in agreement with the values calculated using linear theory, and the limit cycle amplitudes were generally on the order of the shell thickness. The effect of axial tension was studied for this configuration, and increasing tension was found to decrease the limit cycle amplitudes when the circumferential

  5. Synthesis, growth, morphology of the semiorganic nonlinear optical crystal L-glutamic acid hydrochloride and its structural, thermal and SHG characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Dhanasekaran, P.; Srinivasan, K. [Crystal Growth Laboratory, Department of Physics, School of Physical Sciences, Bharathiar University, Coimbatore-641 046, Tamil Nadu (India)

    2012-12-15

    One of the halide derivatives of L-glutamic acid which was identified as a semiorganic nonlinear optical material, L-glutamic acid hydrochloride [HOOC(CH{sub 2}){sub 2}CH(NH{sub 2})COOH.HCl], was grown as bulk single crystal and its significant properties were characterized. The stoichiometric title compound was synthesized and the solubility of its recrystallized form in DD water was determined in the temperature range 30-80 C by gravimetric method. Structural confirmation was carried out by powder X-ray diffraction study through lattice parameter verification. Optical quality smaller dimension single crystals were grown from aqueous solution by self nucleation through slow evaporation of solvent method and a large dimension single crystal was grown by slow cooling method with reversible seed rotation technique. Morphological importances of different growth facets of the as grown crystals were studied through optical goniometry. Unit cell structure of the grown crystal was refined by single crystal X-ray diffraction analysis, functional groups present in the crystal responsible for various modes of vibrations were confirmed by FTIR spectroscopy analysis, thermal stability of the grown crystal was analysed by TG/DTA and DSC and second harmonic generation (SHG) of a fundamental Nd:YAG laser beam by Kurtz technique. Results indicate that the grown crystal is in stoichiometric composition and has significant improvement in its thermal and SHG properties when compared to pure L-glutamic acid polymorphs. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Crystal growth, vibrational, optical, thermal and theoretical studies of a nonlinear optical material: 2-Methyl 3,5-dinitrobenzoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Sangeetha, K. [Department of Physics, Sri Sarada College for Women, Salem-16 (India); Guru Prasad, L. [Department of Science & Humanities, M. Kumarasamy College of Engineering, Karur (India); Mathammal, R. [Department of Physics, Sri Sarada College for Women, Salem-16 (India)

    2016-11-15

    Single crystals of 2-methyl 3,5-dinitro benzoic acid with reasonable size have been grown by slow evaporation solution growth method using ethanol as solvent. Quantum chemical calculation of 2-methyl 3,5-Dinitro benzoic acid was carried out by using DFT/B3LYP/6-31+G(d,p) method. The powder X-ray diffraction pattern was recorded and indexed. Both the experimental and theoretical vibrational spectrum validates the presence of functional groups. Polarizability, first order hyperpolarizability and the electric dipole moment values have been computed theoretically. The {sup 1}H and {sup 13}C NMR chemical shift of the molecule was calculated and compared with experimental results. TG/DSC analysis has been employed to understand the thermal and physio-chemical stability of the title compound. Frequency conversion property of the crystal was tested by Kurtz and Perry method. Optical absorption behavior of the grown crystal was examined by recording the optical spectrum and band gap energy was also estimated. The calculated HOMO and LUMO energy shows the charge transfer nature of the molecule.

  7. Synthesis, growth, structural, optical, thermal and mechanical properties of an organic Urea maleic acid single crystals for nonlinear optical applications

    Science.gov (United States)

    Vinothkumar, P.; Kumar, R. Mohan; Jayavel, R.; Bhaskaran, A.

    2016-07-01

    A potential organic urea maleic acid (UMA) was synthesized and single crystals were grown at room temperature by slow evaporation and seed rotation methods. The grown crystal has been subjected to single crystal XRD analysis and found to have been crystallized in a noncentrosymmetric monoclinic crystal system with Cc as space group. The High resolution X-ray diffraction analysis revealed that the specimen is free from structural grain boundaries. The transparency of the grown crystal was confirmed by optical absorption and transmittance spectra with lower cut-off wavelength of 285 nm. The microhardness test was carried out on different planes to study the load dependent hardness values. The dislocation density of the UMA crystal was estimated from the etching studies. The dielectric permittivity and dielectric loss of the grown crystal was carried out as a function of frequency for different temperatures along three crystallographic axes. Thermal properties of UMA crystals were studied by TG-DTA analysis and it is stable upto 112 °C. The laser induced surface damage threshold of the grown crystal was measured using Nd: YAG laser. The birefringence of the crystal measured in the visible region was found to vary with the wavelength. The particle size dependent SHG of the sample was measured with different input energies by Kurtz's powder method using Nd:YAG laser.

  8. Crystal growth, vibrational, optical, thermal and theoretical studies of a nonlinear optical material: 2-Methyl 3,5-dinitrobenzoic acid

    Science.gov (United States)

    Sangeetha, K.; Guru Prasad, L.; Mathammal, R.

    2016-11-01

    Single crystals of 2-methyl 3,5-dinitro benzoic acid with reasonable size have been grown by slow evaporation solution growth method using ethanol as solvent. Quantum chemical calculation of 2-methyl 3,5-Dinitro benzoic acid was carried out by using DFT/B3LYP/6-31+G(d,p) method. The powder X-ray diffraction pattern was recorded and indexed. Both the experimental and theoretical vibrational spectrum validates the presence of functional groups. Polarizability, first order hyperpolarizability and the electric dipole moment values have been computed theoretically. The 1H and 13C NMR chemical shift of the molecule was calculated and compared with experimental results. TG/DSC analysis has been employed to understand the thermal and physio-chemical stability of the title compound. Frequency conversion property of the crystal was tested by Kurtz and Perry method. Optical absorption behavior of the grown crystal was examined by recording the optical spectrum and band gap energy was also estimated. The calculated HOMO and LUMO energy shows the charge transfer nature of the molecule.

  9. Grey matter pathology in multiple sclerosis.

    Science.gov (United States)

    Vercellino, Marco; Plano, Federica; Votta, Barbara; Mutani, Roberto; Giordana, Maria Teresa; Cavalla, Paola

    2005-12-01

    The aim of our study is to evaluate the extent and distribution of grey matter demyelinating lesions in multiple sclerosis (MS), addressing also neuronal loss and synaptic loss. Whole coronal sections of 6 MS brains and 6 control brains were selected. Immunohistochemistry was performed for myelin basic protein, neurofilaments, synaptophysin, ubiquitin, and activated caspase-3. Neuronal density and optical density of synaptophysin staining were estimated in cortical lesions and compared with those observed in corresponding areas of normal (i.e. nondemyelinated) cortex in the same section. Demyelinating lesions were observed in the cerebral cortex, in the thalamus, basal ganglia, and in the hippocampus. The percentage of demyelinated cortex was remarkable in 2 cases of secondary progressive MS (48% and 25.5%, respectively). Neuronal density was significantly reduced in cortical lesions (18-23% reduction), if compared with adjacent normal cortex, in the 2 cases showing the higher extent of cortical demyelination; in the same cases, very rare apoptotic neurons expressing caspase-3 were observed in cortical lesions and not in adjacent normal cortex. No significant decrease in optical density of synaptophysin staining was observed in cortical lesions. Grey matter demyelination and neuronal loss could contribute to disability and cognitive dysfunctions in MS.

  10. On grey levels in random CAPTCHA generation

    Science.gov (United States)

    Newton, Fraser; Kouritzin, Michael A.

    2011-06-01

    A CAPTCHA is an automatically generated test designed to distinguish between humans and computer programs; specifically, they are designed to be easy for humans but difficult for computer programs to pass in order to prevent the abuse of resources by automated bots. They are commonly seen guarding webmail registration forms, online auction sites, and preventing brute force attacks on passwords. In the following, we address the question: How does adding a grey level to random CAPTCHA generation affect the utility of the CAPTCHA? We treat the problem of generating the random CAPTCHA as one of random field simulation: An initial state of background noise is evolved over time using Gibbs sampling and an efficient algorithm for generating correlated random variables. This approach has already been found to yield highly-readable yet difficult-to-crack CAPTCHAs. We detail how the requisite parameters for introducing grey levels are estimated and how we generate the random CAPTCHA. The resulting CAPTCHA will be evaluated in terms of human readability as well as its resistance to automated attacks in the forms of character segmentation and optical character recognition.

  11. Fundamental definitions and calculation rules of grey mathematics:a review work

    Institute of Scientific and Technical Information of China (English)

    Qiaoxing Li; Sifeng Liu; Jeffrey Yi-Lin Forrest

    2015-01-01

    Grey mathematics is the mathematical foundation of the grey system theory. Recently, some important results have been achieved. In order to accelerate the development of grey math-ematics, the results are summarized and redefined. This paper includes the fundamental definitions and calculation rules of the grey hazy set, grey number, grey matrix and grey function. Grey mathematics includes four types of operation, i.e. the grey oper-ation, the whitened operation, the covered operation and the only potential true operation. According to its intrinsic quality, the cov-ered operation, which differs from the interval one, is cal ed as the whole-proximate calculation that means the proximate calculation spreads through the whole range of the covered set of every grey number, and we confirm that it may be a new branch of compu-tational or applied mathematics. The overview should develop the grey system theory and grey mathematics.

  12. Studies on the synthesis, spectral, optical and thermal properties of l-Valine Zinc Sulphate: an organic inorganic hybrid nonlinear optical crystal.

    Science.gov (United States)

    Puhal Raj, A; Ramachandra Raja, C

    2012-11-01

    Nonlinear optical (NLO) organic inorganic hybrid l-Valine Zinc Sulphate (LVZS) was synthesized and single crystals were obtained from saturated aqueous solution by slow evaporation method at 36°C using a constant temperature bath (CTB) with an accuracy of ±0.01°C. This crystal is reported with its characterization by single crystal and powder XRD, FTIR, UV-Vis-NIR, TG/DTA analysis and SHG test. Single crystal XRD study reveals that LVZS crystallizes in monoclinic system with the lattice constants a=9.969(3) Å, b=7.238(3) Å, c=24.334(9) Å and cell volume is 1736.00Å(3). Sharp peaks observed in powder X-ray diffraction studies confirm the high degree of crystallinity of grown crystal. The incorporation of sulphate ion with l-valine is confirmed by FTIR spectrum in LVZS crystal(.) A remarkable increase in optical transparency has been observed in LVZS when compared to l-valine and zinc sulphate heptahydrate Thermal properties of LVZS have been reported by using TG/DTA analysis. Kurtz powder second harmonic generation (SHG) test confirms NLO property of the crystal and SHG efficiency of LVZS was found to be 1.34 times more than pure l-valine.

  13. Crystal growth, perfection, linear and nonlinear optical, photoconductivity, dielectric, thermal and laser damage threshold properties of 4-methylimidazolium picrate: an interesting organic crystal for photonic and optoelectronic devices

    Science.gov (United States)

    Rajesh, K.; Arun, A.; Mani, A.; Praveen Kumar, P.

    2016-10-01

    The 4-methylimidazolium picrate has been synthesized and characterized successfully. Single and powder x-ray diffraction studies were conducted which confirmed the crystal structure, and the value of the strain was calculated. The crystal perfection was determined by a HRXR diffractometer. The transmission spectrum exhibited a better transmittance of the crystal in the entire visible region with a lower cut-off wavelength of 209 nm. The linear absorption value was calculated by the optical limiting method. A birefringence study was also carried out. Second and third order nonlinear optical properties of the crystal were found by second harmonic generation and the z-scan technique. The crystals were also characterized by dielectric measurement and a photoconductivity analyzer to determine the dielectric property and the optical conductivity of the crystal. The laser damage threshold activity of the grown crystal was studied by a Q-switched Nd:YAG laser beam. Thermal studies established that the compound did not undergo a phase transition and was stable up to 240 °C.

  14. Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-chloro 4-nitrostilbene (CONS): a potential NLO material.

    Science.gov (United States)

    Dinakaran, Paul M; Kalainathan, S

    2013-07-01

    4-Chloro 4-nitrostilbene (CONS) a new organic nonlinear optical material has been synthesized. Employing slow evaporation method, good optical quality single crystals (dimensions up to 6×2×3 mm(3)) have been grown using ethyl methyl ketone (EMK) as a solvent. The grown crystals have been subjected to various characterizations such as single crystal X-ray diffraction, powder XRD, Fourier Transform Infrared spectroscopy (FTIR), proton NMR, solid UV absorption, SHG studies. Single crystal X-ray diffraction reveals that the crystal system belongs to monoclinic with noncentrosymmetric space group P21. The UV-Vis absorption spectrum has been recorded and found that the cut off wavelength is 380 nm. Functional groups and the structure of the title compound have been confirmed by FTIR and (1)H NMR spectroscopic analyses respectively. Molecular mass of the CONS confirmed by the high resolution mass spectral analysis .The thermal behavior of the grown crystal has been studied by TG/DTA analysis and it shows the melting point is at 188.66 °C. Dislocations and growth pattern present in the grown crystal revealed by the etching study. The mechanical strength of the CONS crystal has been studied by Vicker's hardness measurement. The SHG efficiency of the grown crystal has been determined by Kurtz and Perry powder test which revealed that the CONS crystal (327 mV) has 15 times greater efficiency than that of KDP (21.7 mV).

  15. Studies on the synthesis, spectral, optical and thermal properties of L-Valine Zinc Sulphate: An organic inorganic hybrid nonlinear optical crystal

    Science.gov (United States)

    Puhal Raj, A.; Ramachandra Raja, C.

    2012-11-01

    Nonlinear optical (NLO) organic inorganic hybrid L-Valine Zinc Sulphate (LVZS) was synthesized and single crystals were obtained from saturated aqueous solution by slow evaporation method at 36 °C using a constant temperature bath (CTB) with an accuracy of ±0.01 °C. This crystal is reported with its characterization by single crystal and powder XRD, FTIR, UV-Vis-NIR, TG/DTA analysis and SHG test. Single crystal XRD study reveals that LVZS crystallizes in monoclinic system with the lattice constants a = 9.969(3) Å, b = 7.238(3) Å, c = 24.334(9) Å and cell volume is 1736.00 Å3. Sharp peaks observed in powder X-ray diffraction studies confirm the high degree of crystallinity of grown crystal. The incorporation of sulphate ion with L-valine is confirmed by FTIR spectrum in LVZS crystal. A remarkable increase in optical transparency has been observed in LVZS when compared to L-valine and zinc sulphate heptahydrate Thermal properties of LVZS have been reported by using TG/DTA analysis. Kurtz powder second harmonic generation (SHG) test confirms NLO property of the crystal and SHG efficiency of LVZS was found to be 1.34 times more than pure L-valine.

  16. Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-chloro 4-nitrostilbene (CONS): A potential NLO material

    Science.gov (United States)

    Dinakaran, Paul M.; Kalainathan, S.

    2013-07-01

    4-Chloro 4-nitrostilbene (CONS) a new organic nonlinear optical material has been synthesized. Employing slow evaporation method, good optical quality single crystals (dimensions up to 6 × 2 × 3 mm3) have been grown using ethyl methyl ketone (EMK) as a solvent. The grown crystals have been subjected to various characterizations such as single crystal X-ray diffraction, powder XRD, Fourier Transform Infrared spectroscopy (FTIR), proton NMR, solid UV absorption, SHG studies. Single crystal X-ray diffraction reveals that the crystal system belongs to monoclinic with noncentrosymmetric space group P21. The UV-Vis absorption spectrum has been recorded and found that the cut off wavelength is 380 nm. Functional groups and the structure of the title compound have been confirmed by FTIR and 1H NMR spectroscopic analyses respectively. Molecular mass of the CONS confirmed by the high resolution mass spectral analysis .The thermal behavior of the grown crystal has been studied by TG/DTA analysis and it shows the melting point is at 188.66 °C. Dislocations and growth pattern present in the grown crystal revealed by the etching study. The mechanical strength of the CONS crystal has been studied by Vicker's hardness measurement. The SHG efficiency of the grown crystal has been determined by Kurtz and Perry powder test which revealed that the CONS crystal (327 mV) has 15 times greater efficiency than that of KDP (21.7 mV).

  17. Black, grey and white-box approaches to understanding catchment-wide hydrologic connectivity

    Science.gov (United States)

    Ali, G. A.; Roy, A. G.

    2009-12-01

    Connectivity is associated with nonlinear hydrological responses as it is believed to lead to drastic changes in the delivery of stormwater to the stream. Quantitative evidence of connectivity is therefore needed if the concept is to serve as a diagnostic tool for hydrologic behaviours. Recent publications advocate that geostatistical connectivity is a universal measure as it transcends catchment idiosyncracies and allows for the detection of transitions and thresholds in flow processes. Yet, the geostatistical framework failed to reflect threshold change in runoff response in a temperate humid forested catchment (Mont St-Hilaire, Quebec). In this study based on a forested catchment from the Canadian Shield (St-Hippolyte, Quebec), we use three types of hydrological data analysis in searching for evidence of connectivity: (1) statistical classification techniques applied to meteorological records and storm hydrographs; (2) end-member mixing computations performed on stream and source areas geochemistry; and (3) catchment-wide multiple-depths soil moisture data subjected to pattern analysis. These methods correspond respectively to black, grey and white-box approaches towards understanding connectivity. Since the methods can be discriminated by accessibility, physical basis, robustness and spatial discretization, results obtained are compared to assess catchment behavior and prediction uncertainty. The black-box approach reveals that catchment responses, labeled as low/high magnitude and slow/quick timing, can be predicted from meteorological thresholds. It yields indirect evidence of connectivity by suggesting that a relationship between response types and antecedent conditions can be found if assumed nonlinear. The grey-box approach is helpful in identifying time-variable contributing sources to streamflow. Intermediate discharge levels are fed by an enhanced near-surface riparian-stream connection, while both riparian and hillslope areas produce overland flow when

  18. Evaluation of Fabric Hand with Grey Element Model

    Institute of Scientific and Technical Information of China (English)

    CHEN Dong-sheng; GAN Ying-jin; BAI Yue

    2004-01-01

    A premium composite grey element model is established and used for objective evaluation of fabric hand. Fabric hand is regarded as a grey system and the model is composed of fabric mechanical properties, which are primary hand attributes. Based on comparison with a standard model, fabric hand can be objectively evaluated.

  19. Grey Literature Between Tradition and Innovation: Is There a Continuum?

    OpenAIRE

    Pardelli, Gabriella; Goggi, Sara; Sassi, Manuela; GreyNet, Grey Literature Network Service

    2011-01-01

    This study wants to explore new ways of social media communication for Grey Literature. In particular it describes the role of social media in relation with traditional channels and how social media applications can be used for Grey. Includes: Conference preprint, Powerpoint presentation, Abstract and Biographical notes XA International

  20. Effect of titanium on the near eutectic grey iron

    DEFF Research Database (Denmark)

    Moumeni, Elham; Tiedje, Niels Skat; Hattel, Jesper Henri

    The effect of Titanium on the microstructure of grey iron was investigated experimentally in this work. Tensile test bars of grey cast iron of near eutectic alloys containing 0.01, 0.1, 0.26 and 0.35% Ti, respectively were made in green sand moulds. Chemical analysis, metallographic investigation...

  1. The Comparative Study of Grey Literature Orgnization at Home and Abroad in Network Environment

    OpenAIRE

    Xu, Liu Jing

    2005-01-01

    Grey literature is an important information resource , and Internet makes it easier to organize them. This paper introduces how the System for Information on Grey Literature in Europe(SIGLE) and GreyNet organize the grey literature. And then it presents how to organize grey literature in China in network environment. Finally, by contrast a conclusion is drawn that there are several disadvantages in the grey literature organization in China.

  2. Repozitář a webový portál GreyGuide:Odpověď GreyNet na Deklaraci z Pisy

    OpenAIRE

    Farace, Dominic

    2014-01-01

    In December 2013, the GreyGuide was launched and in early 2014 GreyNet welcomed far reaching developments in its resource management. These developments are in line with the “Pisa Declaration on Policy Development for Grey Literature Resources (May 16, 2014)”. In compliance with this 15-point roadmap, a selection of GreyNet’s web-based content will now migrate to the GreyGuide allowing for seamless browse, search, and retrieval across its collections.

  3. Alternative Axiomatic Characterizations of the Grey Shapley Value

    Directory of Open Access Journals (Sweden)

    Sirma Zeynep Alparslan Gok

    2014-05-01

    Full Text Available The Shapley value, one of the most common solution concepts of cooperative game theory is defined and axiomatically characterized in different game-theoretic models. Certainly, the Shapley value can be used in interesting sharing cost/reward problems in the Operations Research area such as connection, routing, scheduling, production and inventory situations. In this paper, we focus on the Shapley value for cooperative games, where the set of players is finite and the coalition values are interval grey numbers. The central question in this paper is how to characterize the grey Shapley value. In this context, we present two alternative axiomatic characterizations. First, we characterize the grey Shapley value using the properties of efficiency, symmetry and strong monotonicity. Second, we characterize the grey Shapley value by using the grey dividends.

  4. Breatherlike excitations in discrete lattices with noise and nonlinear damping

    DEFF Research Database (Denmark)

    Christiansen, Peter Leth; Gaididei, Yuri B.; Johansson, Magnus

    1997-01-01

    We discuss the stability of highly localized, ''breatherlike,'' excitations in discrete nonlinear lattices under the influence of thermal fluctuations. The particular model considered is the discrete nonlinear Schrodinger equation in the regime of high nonlinearity, where temperature effects...

  5. Phylogeographic history of grey wolves in Europe.

    Science.gov (United States)

    Pilot, Małgorzata; Branicki, Wojciech; Jedrzejewski, Włodzimierz; Goszczyński, Jacek; Jedrzejewska, Bogumiła; Dykyy, Ihor; Shkvyrya, Maryna; Tsingarska, Elena

    2010-04-21

    While it is generally accepted that patterns of intra-specific genetic differentiation are substantially affected by glacial history, population genetic processes occurring during Pleistocene glaciations are still poorly understood. In this study, we address the question of the genetic consequences of Pleistocene glaciations for European grey wolves. Combining our data with data from published studies, we analysed phylogenetic relationships and geographic distribution of mitochondrial DNA haplotypes for 947 contemporary European wolves. We also compared the contemporary wolf sequences with published sequences of 24 ancient European wolves. We found that haplotypes representing two haplogroups, 1 and 2, overlap geographically, but substantially differ in frequency between populations from south-western and eastern Europe. A comparison between haplotypes from Europe and other continents showed that both haplogroups are spread throughout Eurasia, while only haplogroup 1 occurs in contemporary North American wolves. All ancient wolf samples from western Europe that dated from between 44,000 and 1,200 years B.P. belonged to haplogroup 2, suggesting the long-term predominance of this haplogroup in this region. Moreover, a comparison of current and past frequencies and distributions of the two haplogroups in Europe suggested that haplogroup 2 became outnumbered by haplogroup 1 during the last several thousand years. Parallel haplogroup replacement, with haplogroup 2 being totally replaced by haplogroup 1, has been reported for North American grey wolves. Taking into account the similarity of diets reported for the late Pleistocene wolves from Europe and North America, the correspondence between these haplogroup frequency changes may suggest that they were associated with ecological changes occurring after the Last Glacial Maximum.

  6. A Hybrid Approach by Integrating Brain Storm Optimization Algorithm with Grey Neural Network for Stock Index Forecasting

    Directory of Open Access Journals (Sweden)

    Yanqiu Sun

    2014-01-01

    Full Text Available Stock index forecasting is an important tool for both the investors and the government organizations. However, due to the inherent large volatility, high noise, and nonlinearity of the stock index, stock index forecasting has been a challenging task for a long time. This paper aims to develop a novel hybrid stock index forecasting model named BSO-GNN based on the brain storm optimization (BSO approach and the grey neural network (GNN model by taking full advantage of the grey model in dealing with data with small samples and the neural network in handling nonlinear fitting problems. Moreover, the new developed BSO-GNN, which initializes the parameters in grey neural network with the BSO algorithm, has great capability in overcoming the deficiencies of the traditional GNN model with randomly initialized parameters through solving the local optimum and low forecasting accuracy problems. The performance of the proposed BSO-GNN model is evaluated under the normalization and nonnormalization preprocessing situations. Experimental results from the Shanghai Stock Exchange (SSE Composite Index, the Shenzhen Composite Index, and the HuShen 300 Index opening price forecasting show that the proposed BSO-GNN model is effective and robust in the stock index forecasting and superior to the individual GNN model.

  7. Scouring Potential of Mesophile Acidic Proteases of Pseudomonas aeruginosa for Grey Cotton Fabrics

    Science.gov (United States)

    Saravanan, D.

    2013-04-01

    Mesophile, acidic proteases were produced using the microbial source, Pseudomonas aeruginosa, with wider thermal tolerances. Process conditions of scouring treatment were optimized using Taguchi method for optimum temperature, time, pH and concentration of protease. Treatment with the protease lower weight loss values compared to the alkali scouring, however, significant improvement in the absorbency compared to the grey samples was observed. Large amounts of pectin left out in the samples resulted in higher extractable impurities, substantiated by the FTIR results. Relatively, lower reduction in the tear strengths was observed in both warp and weft directions after protease treatment of the cotton fabrics.

  8. Exact bright and dark spatial soliton solutions in saturable nonlinear media

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Gabriel F. [Departamento de Matematicas, E.T.S. de Ingenieros Industriales, Instituto de Matematica Aplicada a la Ciencia y la Ingenieria (IMACI), E.T.S.I. Industriales, Avda. Camilo Jose Cela, 3, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Belmonte-Beitia, Juan [Departamento de Matematicas, E.T.S. de Ingenieros Industriales, Instituto de Matematica Aplicada a la Ciencia y la Ingenieria (IMACI), E.T.S.I. Industriales, Avda. Camilo Jose Cela, 3, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)], E-mail: Juan.Belmonte@uclm.es; Perez-Garcia, Victor M. [Departamento de Matematicas, E.T.S. de Ingenieros Industriales, Instituto de Matematica Aplicada a la Ciencia y la Ingenieria (IMACI), E.T.S.I. Industriales, Avda. Camilo Jose Cela, 3, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain)

    2009-08-30

    We present exact analytical bright and dark (black and grey) solitary wave solutions of a nonlinear Schroedinger-type equation describing the propagation of spatial beams in media exhibiting a saturable nonlinearity (such as centrosymmetric photorefractive materials). A qualitative study of the stationary equation is carried out together with a discussion of the stability of the solutions.

  9. Application of Grey System Theory to tree growth prediction

    Institute of Scientific and Technical Information of China (English)

    王晶; 侯月松; 李伟林; 成文惠

    2000-01-01

    Based on Grey System theory, tree growth prediction models are developed by using 202 temporary plots and 206 stem analysis trees of Dahurian larch (Larix gemlinii Rupr.) in 10 forestry bureaus of Yakeshi Forestry Administrative Bureau in Daxing'an Mountains of the Inner Mongolia Autonomous Region. By residual and posterior tests, their precisions are qualified. With several data, tree growth can be predicted using Grey System models. For DBH and volume, the fitting results of Grey System models are better than that of statistical models.

  10. Growth and reproduction in the Icelandic grey seal

    OpenAIRE

    2013-01-01

    Growth and reproduction in grey seals (Halichoerus grypus Fabricius, 1791) from Iceland were examined. The oldest Icelandic grey seals obtained were a 36 year old female and a 23 year old male. The longest animals were a 255 cm 13 year old male, and a 230 cm 20 year old female. The heaviest grey seal was an 11 year old male weighing 310 kg. The heaviest female was a 20 year old female that weighed 240 kg. Females reached an asymptotic standard length and weight of 200 (95% CI 196 - 204) cm an...

  11. Quantitative inspection on graphite length of grey iron

    Institute of Scientific and Technical Information of China (English)

    CAI Ming-dong; SUN Guo-xiong

    2007-01-01

    Graphite length is an important item in metallographic inspection of grey iron. Computer aided quantitative metallography is developed rapidly and has become a major analytical tool nowadays. Based-moment threshold selection was adopted to binarize the metallographic image in this study. A new approach has been developed to measure the length of the graphite in cast iron with high precision. The results are in good agreement with China National Metallographic Inspection Standard Charts for Grey Iron (GB7216-87) and ASTM (A247-67). An objective and precise measurement of graphite length in grey iron is critical for developing models correlating microstructure and properties of cast iron.

  12. Optothermal nonlinearity of silica aerogel

    CERN Document Server

    Braidotti, Maria Chiara; Fleming, Adam; Samuels, Michiel C; Di Falco, Andrea; Conti, Claudio

    2016-01-01

    We report on the characterization of silica aerogel thermal optical nonlinearity, obtained by z-scan technique. The results show that typical silica aerogels have nonlinear optical coefficient similar to that of glass $(\\simeq 10^{-12} $m$^2/$W), with negligible optical nonlinear absorption. The non\\-li\\-near coefficient can be increased to values in the range of $10^{-10} $m$^2/$W by embedding an absorbing dye in the aerogel. This value is one order of magnitude higher than that observed in the pure dye and in typical highly nonlinear materials like liquid crystals.

  13. Grey seal predation on forage fish in the Baltic Sea

    DEFF Research Database (Denmark)

    Eero, Aro; Neuenfeldt, Stefan; Aho, Teija;

    has increased accordingly. The diet of grey seal in the Baltic consists of ca. 20 fish species. The most abundant prey items in the Baltic proper are Baltic herring, sprat, and cod, and in the Bothnian Sea and Bothnian Bay Baltic herring, Coregonus sp., Baltic salmon, and sea trout. An adult seal...... consumes on average round 4.5 kg fish per day, of which 55% are clupeoids in the Baltic Main basin and 70% in the Bothnian Sea and Bothnian Bay. According to acoustic estimates, predator– prey distribution patterns, migration patterns, and multispecies analysis (SMS), the predation effect of grey seals...... on Baltic herring and sprat stocks is still at a very low level. Hence, with present grey seal stock sizes, the impact of seal predation can be ignored in whole Baltic‐scale herring and sprat stock management considerations. Locally, however, grey seal–fishery interactions play an important role and should...

  14. Invenio: A Modern Digital Library for Grey Literature

    CERN Document Server

    Caffaro, Jerome

    2010-01-01

    Grey literature has historically played a key role for researchers in the field of High- Energy Physics (HEP). Consequently CERN (European Organization for Nuclear Research) as the world’s largest particle physics laboratory has always been facing the challenge of distributing and archiving grey material. Invenio, an open-source repository software, has been developed as part of CERN’s institutional repository strategy to answer these needs. In this document we describe how the particular context of grey literature within the HEP community shaped the development of Invenio. We focus on the strategies that have been established in order to process grey material within the software and we analyse how it is used in a real production environment, the CERN Document Server (CDS).

  15. How to search for and use 'grey literature' in research.

    Science.gov (United States)

    Coad, Jane; Hardicre, Jayne; Devitt, Patric

    An ever-growing amount of grey literature is available to nurses, including oral presentations, personal communication, leaflets, newspapers and magazines, unpublished research, internal reports and minutes of meetings. It can be an invaluable research resource.

  16. Prediction Model of Sewing Technical Condition by Grey Neural Network

    Institute of Scientific and Technical Information of China (English)

    DONG Ying; FANG Fang; ZHANG Wei-yuan

    2007-01-01

    The grey system theory and the artificial neural network technology were applied to predict the sewing technical condition. The representative parameters, such as needle, stitch, were selected. Prediction model was established based on the different fabrics' mechanical properties that measured by KES instrument. Grey relevant degree analysis was applied to choose the input parameters of the neural network. The result showed that prediction model has good precision. The average relative error was 4.08% for needle and 4.25% for stitch.

  17. Copyright licenses and legal deposit practices of grey multimedia materials

    OpenAIRE

    Debbie L. Rabina; GreyNet, Grey Literature Network Service

    2008-01-01

    The purpose of this study is to determine whether the type of copyright license under which grey multimedia materials are published makes a difference in terms of their inclusion in library catalogs. The two types of copyright licenses examined are Creative Commons and traditional copyright, and the library catalogs examined is that of the United States Library of Congress and national catalogs of countries represented in the population of the study. The population included grey multimedia ma...

  18. WorldWideScience.org: Bringing Light to Grey

    OpenAIRE

    Hitson, Brian A. (OSTI-DOE); Johnson, Lorrie A; GreyNet, Grey Literature Network Service

    2008-01-01

    WorldWideScience.org and its governance structure, the WorldWideScience Alliance, are putting a brighter spotlight on grey literature. Through this new tool, grey literature is getting broader exposure to audiences all over the world. Improved access to and sharing of research information is the key to accelerating progress and breakthroughs in any field, especially science. Includes: Conference preprint, Powerpoint presentation, Abstract and Biographical notes, Pratt student commentary ...

  19. WorldWideScience.org: Bringing Light to Grey

    OpenAIRE

    Hitson, Brian A. (OSTI-DOE); Johnson, Lorrie A. (OSTI-DOE); GreyNet, Grey Literature Network Service

    2008-01-01

    WorldWideScience.org and its governance structure, the WorldWideScience Alliance, are putting a brighter spotlight on grey literature. Through this new tool, grey literature is getting broader exposure to audiences all over the world. Improved access to and sharing of research information is the key to accelerating progress and breakthroughs in any field, especially science. Includes: Conference preprint, Powerpoint presentation, Abstract and Biographical notes, Pratt student commentary ...

  20. Unusual MRI findings in grey matter heteropia

    Energy Technology Data Exchange (ETDEWEB)

    Soto Ares, G.; Hamon-Kerautret, M.; Leclerc, X.; Pruvo, J.P. [Service de Neuroradiologie, Hopital Roger Salengro, CHRU, Lille (France); Houlette, C. [Service de Radiologie, CHRU, Rouen (France); Godefroy, O. [Service de Neurologie B, CHRU, Lille (France)

    1998-02-01

    We report unusual MRI patterns in patients with grey matter heterotopia. Standard T1- and T2-weighted spin-echo and inversion-recovery sequences were used in 22 patients presenting with seizures or developmental delay. The images were reviewed for signal change surrounding white matter and for atypical size, morphology or topography. We found 10 cases of subependymal heterotopias 11 of focal subcortical heterotopia and of diffuse subcortical heterotopia. On clinical or MRI grounds, 8 cases were considered unusual: 2 of the subependymal type, 2 of focal subcortical heterotopia with white matter abnormalities, 2 of focal subcortical heterotopia with no clinicoradiological correlation 1 of extensive hemispheric subcortical heterotopia and 1 of diffuse subcortical heterotopia confined to the frontal lobe. The classical classification of heterotopia enables easy radiological diagnosis even in cases with unusual patterns. In some cases, heterogeneity and high signal in surrounding white matter can be found. Cortical dysplasia is the most frequent associated malformation. (orig.) With 7 figs., 2 tabs., 10 refs.

  1. Analyzing Taiwan IC Assembly Industry by Grey-Markov Forecasting Model

    Directory of Open Access Journals (Sweden)

    Lei-Chuan Lin

    2013-01-01

    Full Text Available This study utilizes the black swan theorem to discuss how to face the lack of historical data and outliers. They may cause huge influences which make it impossible for people to predict the economy from their knowledge or experiences. Meanwhile, they cause the general dilemma of which prediction tool to be used which is also considered in this study. For the reason above, this study uses 2009 Q1 to 2010 Q4 quarterly revenue trend of Taiwan’s semiconductor packaging and testing industry under the global financial turmoil as basis and the grey prediction method to deal with nonlinear problems and small data. Under the lack of information and economic drastic changes, this study applies Markov model to predict the industry revenues of GM(1,1 and DGM(1,1 results. The results show that the accuracy of 2010 Q1–Q3 is 88.37%, 90.27%, sand 91.13%, respectively. Besides, they are better than the results of GM(1,1 and DGM(1,1 which are 86.51%, 77.35%, 75.46% and 73.77%, 74.25%, 59.72%. The results show that the prediction ability of the grey prediction with Markov model is better than traditional GM(1,1 and DGM(1,1 sfacing the changes of financial crisis. The results also prove that the grey-Markov chain prediction can be the perfect criterion for decision-makers judgment even when the environment has undergone drastic changes which bring the impact of unpredictable conditions.

  2. Soil infiltration based on bp neural network and grey relational analysis

    Directory of Open Access Journals (Sweden)

    Wang Juan

    2013-02-01

    Full Text Available Soil infiltration is a key link of the natural water cycle process. Studies on soil permeability are conducive for water resources assessment and estimation, runoff regulation and management, soil erosion modeling, nonpoint and point source pollution of farmland, among other aspects. The unequal influence of rainfall duration, rainfall intensity, antecedent soil moisture, vegetation cover, vegetation type, and slope gradient on soil cumulative infiltration was studied under simulated rainfall and different underlying surfaces. We established a six factor-model of soil cumulative infiltration by the improved back propagation (BP-based artificial neural network algorithm with a momentum term and self-adjusting learning rate. Compared to the multiple nonlinear regression method, the stability and accuracy of the improved BP algorithm was better. Based on the improved BP model, the sensitive index of these six factors on soil cumulative infiltration was investigated. Secondly, the grey relational analysis method was used to individually study grey correlations among these six factors and soil cumulative infiltration. The results of the two methods were very similar. Rainfall duration was the most influential factor, followed by vegetation cover, vegetation type, rainfall intensity and antecedent soil moisture. The effect of slope gradient on soil cumulative infiltration was not significant.

  3. An improvement in rollover detection of articulated vehicles using the grey system theory

    Science.gov (United States)

    Chou, Tao; Chu, Tzyy-Wen

    2014-05-01

    A Rollover Index combined with the grey system theory, called a Grey Rollover Index (GRI), is proposed to assess the rollover threat for articulated vehicles with a tractor-semitrailer combination. This index can predict future trends of vehicle dynamics based on current vehicle motion; thus, it is suitable for vehicle-rollover detection. Two difficulties are encountered when applying the GRI for rollover detection. The first difficulty is effectively predicting the rollover threat of the vehicles, and the second difficulty is achieving a definite definition of the real rollover timing of a vehicle. The following methods are used to resolve these problems. First, a nonlinear mathematical model is constructed to accurately describe the vehicle dynamics of articulated vehicles. This model is combined with the GRI to predict rollover propensity. Finally, TruckSim™ software is used to determine the real rollover timing and facilitate the accurate supply of information to the rollover detection system through the GRI. This index is used to verify the simulation based on the common manoeuvres that cause rollover accidents to reduce the occurrence of false signals and effectively increase the efficiency of the rollover detection system.

  4. Studies on synthesis, structural, luminescent and thermal properties of a new non-linear optical crystal: 4-amino-4H-1,2,4-triazol-1-ium-3-hydroxy-2,4,6-trinitrophenolate

    Energy Technology Data Exchange (ETDEWEB)

    Dhamodharan, P.; Sathya, K.; Dhandapani, M., E-mail: chemistrydhandapani@gmail.com

    2017-03-01

    A new organic proton transfer complex having NLO activity, 4-amino-4H-1,2,4-triazol-1-ium-3-hydroxy-2,4,6-trinitrophenolate (ATHTP), was crystallized to investigate the factors which stabilize the structure of the crystal. The compound crystallizes in triclinic system with space group P-1. Elemental analysis, thermal analysis, UV–Vis–NIR, FT-IR and NMR spectral analyses were carried out to characterize the crystal. Optical, spectral and thermal properties of the title crystal were analyzed to recommend the material for optical applications. Z-scan was used to measure the effective third-order nonlinear optical susceptibility and nonlinear refractive index. The crystal structure was determined using single crystal XRD method and the structure was optimized using Gaussian 09 program at B3LYP/6-311++G(d,p) level of basis set. This hydrogen bond interactions led to the increase in first-order hyperpolarizability of ATHTP and was 30 times greater than that of urea. Hirshfeld analyses surface analysis was carried out to explore intermolecular interactions in the crystalline state. - Highlights: • Single crystals were grown by slow evaporation solution growth technique. • N-H…O, O-H…O and C-H…O type of interactions lead to stable network. • The thermal stability of the compound was investigated by TG/DTA analyses. • The third-order nonlinear optical susceptibility is found to be 2.1×10{sup −7} esu. • Hirshfeld analyses explore covalent and non covalent interactions.

  5. Assessment of global grey water footprint of major food crops

    Science.gov (United States)

    Yang, Hong; Liu, Wenfeng; Antonelli, Marta

    2016-04-01

    Agricultural production is one of the major sources of water pollution in the world. This is closely related to the excess application of fertilizers. Leaching of N and P to water bodies has caused serious degradation of water quality in many places. With the persistent increase in the demand for agricultural products, agricultural intensification evident during the past decades will continue in the future. This will lead to further increase in fertilizer application and consequently water pollution. Grey water footprint is a measure of the intensity of water pollution caused by water use for human activities. It is defined as the volume of water that is required to assimilate a load of pollutants to a freshwater body, based on natural background concentrations and water quality standards. This study conducts a global assessment of grey water footprint for major cereal crops, wheat, maize and rice. A crop model, Python-based EPIC (PEPIT), is applied to quantify the leaching of N and P from the fertilizer application in the three crops on a global scale with 0.5 degree spatial resolution. The hotspots of leaching are identified. The results suggest that, based on the definition and method of grey water footprint proposed by the World Water Footprint Network, the grey water footprint in many parts of the world has exceeded their total water resources availability. This indicates the seriousness of water pollution caused by agricultural production. However, the situation may also call for the development of a realistic measurement of grey water footprint which is more pertinent to water resources management. This paper proposes some alternatives in measuring grey water footprint and also discusses incorporation of grey water footprint assessment into water policy formulation and river basins plan development.

  6. Relationship between grey matter integrity and executive abilities in aging.

    Science.gov (United States)

    Manard, Marine; Bahri, Mohamed Ali; Salmon, Eric; Collette, Fabienne

    2016-07-01

    This cross-sectional study was designed to investigate grey matter changes that occur in healthy aging and the relationship between grey matter characteristics and executive functioning. Thirty-six young adults (18-30 years old) and 43 seniors (60-75 years old) were included. A general executive score was derived from a large battery of neuropsychological tests assessing three major aspects of executive functioning (inhibition, updating and shifting). Age-related grey matter changes were investigated by comparing young and older adults using voxel-based morphometry and voxel-based cortical thickness methods. A widespread difference in grey matter volume was found across many brain regions, whereas cortical thinning was mainly restricted to central areas. Multivariate analyses showed age-related changes in relatively similar brain regions to the respective univariate analyses but appeared more limited. Finally, in the older adult sample, a significant relationship between global executive performance and decreased grey matter volume in anterior (i.e. frontal, insular and cingulate cortex) but also some posterior brain areas (i.e. temporal and parietal cortices) as well as subcortical structures was observed. Results of this study highlight the distribution of age-related effects on grey matter volume and show that cortical atrophy does not appear primarily in "frontal" brain regions. From a cognitive viewpoint, age-related executive functioning seems to be related to grey matter volume but not to cortical thickness. Therefore, our results also highlight the influence of methodological aspects (from preprocessing to statistical analysis) on the pattern of results, which could explain the lack of consensus in literature.

  7. Nonlinear Schrodinger equation with chaotic, random, and nonperiodic nonlinearity

    CERN Document Server

    Cardoso, W B; Avelar, A T; Bazeia, D; Hussein, M S

    2009-01-01

    In this paper we deal with a nonlinear Schr\\"{o}dinger equation with chaotic, random, and nonperiodic cubic nonlinearity. Our goal is to study the soliton evolution, with the strength of the nonlinearity perturbed in the space and time coordinates and to check its robustness under these conditions. Comparing with a real system, the perturbation can be related to, e.g., impurities in crystalline structures, or coupling to a thermal reservoir which, on the average, enhances the nonlinearity. We also discuss the relevance of such random perturbations to the dynamics of Bose-Einstein Condensates and their collective excitations and transport.

  8. Grey game Theory%灰博弈综述

    Institute of Scientific and Technical Information of China (English)

    陈端芝

    2015-01-01

    灰博弈论是博弈理论与灰色理论相结合的综合性理论。本文系统论述了灰博弈的研究范围、研究现状和应用研究的一般过程。最后简要介绍了灰博弈的应用研究情况和发展趋势,并指出灰博弈论可作为研究社会、经济问题的有力工具。%The grey game theory is the combination of game theory and grey theory is a comprehensive theory. This article system elaborated the grey game research scope, research status and applications of general process. Finaly a brief introduction to the application of grey game research situation and development trend, and points out that the grey game theory can be used as a powerful tool for social and economic problems.

  9. Optimal design of green and grey stormwater infrastructure for small urban catchment based on life-cycle cost-effectiveness analysis

    Science.gov (United States)

    Yang, Y.; Chui, T. F. M.

    2016-12-01

    Green infrastructure (GI) is identified as sustainable and environmentally friendly alternatives to the conventional grey stormwater infrastructure. Commonly used GI (e.g. green roof, bioretention, porous pavement) can provide multifunctional benefits, e.g. mitigation of urban heat island effects, improvements in air quality. Therefore, to optimize the design of GI and grey drainage infrastructure, it is essential to account for their benefits together with the costs. In this study, a comprehensive simulation-optimization modelling framework that considers the economic and hydro-environmental aspects of GI and grey infrastructure for small urban catchment applications is developed. Several modelling tools (i.e., EPA SWMM model, the WERF BMP and LID Whole Life Cycle Cost Modelling Tools) and optimization solvers are coupled together to assess the life-cycle cost-effectiveness of GI and grey infrastructure, and to further develop optimal stormwater drainage solutions. A typical residential lot in New York City is examined as a case study. The life-cycle cost-effectiveness of various GI and grey infrastructure are first examined at different investment levels. The results together with the catchment parameters are then provided to the optimization solvers, to derive the optimal investment and contributing area of each type of the stormwater controls. The relationship between the investment and optimized environmental benefit is found to be nonlinear. The optimized drainage solutions demonstrate that grey infrastructure is preferred at low total investments while more GI should be adopted at high investments. The sensitivity of the optimized solutions to the prices the stormwater controls is evaluated and is found to be highly associated with their utilizations in the base optimization case. The overall simulation-optimization framework can be easily applied to other sites world-wide, and to be further developed into powerful decision support systems.

  10. Identifying Oil, Oil-water and Water Reservoirs by the Method of Grey Poly-category

    Institute of Scientific and Technical Information of China (English)

    Lu Huangsheng

    1994-01-01

    @@ Grey Poly-category is a branch of Grey System belonging to System Theory. According to the System Theory, a fully determinable figure is called White Figure, a fully undeterminable figure is called Black Figure, and the figure between them is called Grey Figure. On the same principle, a fully determinable system,a fully undeterminable, and a partial determinable and partial undeterminable system are called White, Black and Grey System respectively. For the oil, oil-water and water reservoirs, each type of reservoirs has its different log response values. These values are grey figures, not a fixed figure, and then, the system made of the figures is a Grey System.

  11. Nonlinear optics

    CERN Document Server

    Bloembergen, Nicolaas

    1996-01-01

    Nicolaas Bloembergen, recipient of the Nobel Prize for Physics (1981), wrote Nonlinear Optics in 1964, when the field of nonlinear optics was only three years old. The available literature has since grown by at least three orders of magnitude.The vitality of Nonlinear Optics is evident from the still-growing number of scientists and engineers engaged in the study of new nonlinear phenomena and in the development of new nonlinear devices in the field of opto-electronics. This monograph should be helpful in providing a historical introduction and a general background of basic ideas both for expe

  12. Internet trade and threat of the grey area

    Directory of Open Access Journals (Sweden)

    Anna Ćwiąkała-Małys

    2012-06-01

    Full Text Available In recent years it has been of great interest to tax, fiscal and customs authorities how trade and services provided over the Internet develop. A long time ago it was stated that the intense development of the Internet contributes to the expansion of the grey area. The grey area’s functioning is very unfavourable to the state economy, because although it creates GDP, it does not directly support the state budget. When considering reduced inflows to the state budget and increases in the deficit, it is reasonable to take any and all actions in order to limit the grey area in each field of social and economic life. Thus, the interest of specialized public authorities in this field should not raise any concerns.

  13. Efficiency of searching the grey literature in palliative care.

    Science.gov (United States)

    Cook, A M; Finlay, I G; Edwards, A G; Hood, K; Higginson, I J; Goodwin, D M; Normand, C E; Douglas, H R

    2001-09-01

    A systematic review into palliative care team effectiveness was undertaken which has, inherent in its methodology, grey literature searching. Over 100 letters were written to a systematically chosen range of service providers, commissioners, and experts in combination with requests for information in six UK national cancer/palliative care organization newsletters. In addition, the System for Information on Grey Literature (SIGLE ) database was searched. As a result, 25 document hard copies were received. The documents were, in all but one case (this one study was also highlighted by the SIGLE search), not relevant as they were predominated by annual reports, service descriptions, and needs assessments. In terms of obtaining unpublished studies for possible inclusion in the review, this comprehensive search was unsuccessful and, therefore, it would appear that grey literature searching is not a useful tool in palliative care systematic reviews.

  14. Grey forecasting model for active vibration control systems

    Science.gov (United States)

    Lihua, Zou; Suliang, Dai; Butterworth, John; Ma, Xing; Dong, Bo; Liu, Aiping

    2009-05-01

    Based on the grey theory, a GM(1,1) forecasting model and an optimal GM(1,1) forecasting model are developed and assessed for use in active vibration control systems for earthquake response mitigation. After deriving equations for forecasting the control state vector, design procedures for an optimal active control method are proposed. Features of the resulting vibration control and the influence on it of time-delay based on different sampling intervals of seismic ground motion are analysed. The numerical results show that the forecasting models based on the grey theory are reliable and practical in structural vibration control fields. Compared with the grey forecasting model, the optimal forecasting model is more efficient in reducing the influences of time-delay and disturbance errors.

  15. Studies on synthesis, structural, luminescent and thermal properties of a new non-linear optical crystal: 4-amino-4H-1,2,4-triazol-1-ium-3-hydroxy-2,4,6-trinitrophenolate

    Science.gov (United States)

    Dhamodharan, P.; Sathya, K.; Dhandapani, M.

    2017-03-01

    A new organic proton transfer complex having NLO activity, 4-amino-4H-1,2,4-triazol-1-ium-3-hydroxy-2,4,6-trinitrophenolate (ATHTP), was crystallized to investigate the factors which stabilize the structure of the crystal. The compound crystallizes in triclinic system with space group P-1. Elemental analysis, thermal analysis, UV-Vis-NIR, FT-IR and NMR spectral analyses were carried out to characterize the crystal. Optical, spectral and thermal properties of the title crystal were analyzed to recommend the material for optical applications. Z-scan was used to measure the effective third-order nonlinear optical susceptibility and nonlinear refractive index. The crystal structure was determined using single crystal XRD method and the structure was optimized using Gaussian 09 program at B3LYP/6-311++G(d,p) level of basis set. This hydrogen bond interactions led to the increase in first-order hyperpolarizability of ATHTP and was 30 times greater than that of urea. Hirshfeld analyses surface analysis was carried out to explore intermolecular interactions in the crystalline state.

  16. Nonlinear supratransmission

    Energy Technology Data Exchange (ETDEWEB)

    Geniet, F; Leon, J [Physique Mathematique et Theorique, CNRS-UMR 5825, 34095 Montpellier (France)

    2003-05-07

    A nonlinear system possessing a natural forbidden band gap can transmit energy of a signal with a frequency in the gap, as recently shown for a nonlinear chain of coupled pendulums (Geniet and Leon 2002 Phys. Rev. Lett. 89 134102). This process of nonlinear supratransmission, occurring at a threshold that is exactly predictable in many cases, is shown to have a simple experimental realization with a mechanical chain of pendulums coupled by a coil spring. It is then analysed in more detail. First we go to different (nonintegrable) systems which do sustain nonlinear supratransmission. Then a Josephson transmission line (a one-dimensional array of short Josephson junctions coupled through superconducting wires) is shown to also sustain nonlinear supratransmission, though being related to a different class of boundary conditions, and despite the presence of damping, finiteness, and discreteness. Finally, the mechanism at the origin of nonlinear supratransmission is found to be a nonlinear instability, and this is briefly discussed here.

  17. Fuzzy-grey Prediction of Cutting Force Uncertainty in Turning

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To predict the extent of turning force uncertainty quantitatively,this paper proposes a fuzzy-grey prediction procedure based on the symmetric fuzzy number and linear planning theory and grey set theory.To ve rify the developed procedure,a measuring system of turning force is schematized to acquire the evaluating data.The comparison between the prediction results a nd measured data demonstrates that the prediction is an extent of variable force rather than a certain point for the given turning condition...

  18. Asymptotic variance of grey-scale surface area estimators

    DEFF Research Database (Denmark)

    Svane, Anne Marie

    Grey-scale local algorithms have been suggested as a fast way of estimating surface area from grey-scale digital images. Their asymptotic mean has already been described. In this paper, the asymptotic behaviour of the variance is studied in isotropic and sufficiently smooth settings, resulting...... in a general asymptotic bound. For compact convex sets with nowhere vanishing Gaussian curvature, the asymptotics can be described more explicitly. As in the case of volume estimators, the variance is decomposed into a lattice sum and an oscillating term of at most the same magnitude....

  19. Venture Capital Investment Base on Grey Relational Theory

    Science.gov (United States)

    Zhang, Xubo

    This paper builds a venture capital investment projects selection evaluation model base on risk-weight investment return using grey relational analysis. The risk and return in venture capital investment projects selection process is analyses. These risk and return mainly constricted in management ability, operation ability, market ability, exit obtain and investment cost. The 18 sub-indicators are the impact factors contributed to these five evaluation aspects. Grey relation analysis is use to evaluate the venture capital investment selection. Get the optimal solution of risk-weight double objective investment selection evaluation model. An example is used to demonstrate the model in this paper.

  20. On grey relation projection model based on projection pursuit

    Institute of Scientific and Technical Information of China (English)

    Wang Shuo; Yang Shanlin; Ma Xijun

    2008-01-01

    Multidimensional grey relation projection value can be synthesized as one-dimensional projection value by u-sing projection pursuit model.The larger the projection value is,the better the model.Thus,according to the projection value,the best one can be chosen from the model aggregation.Because projection pursuit modeling based on accelera-ting genetic algorithm can simplify the implementation procedure of the projection pursuit technique and overcome its complex calculation as well as the difficulty in implementing its program,a new method can be obtained for choosing the best grey relation projection model based on the projection pursuit technique.

  1. Improved grey-based approach for power demand forecasting

    Institute of Scientific and Technical Information of China (English)

    LIN Jia-mu; LIU Dan

    2006-01-01

    Grey theory is a multidisciplinary and generic theory to cope with systems of poor or deficient information. We proposed in this paper an improved grey method (GM) to overcome the disadvantages of the general GM(1,1). In the improved GM(1,1), a new background value formula is deduced and Markov-chain sign estimation is imbedded into the residual modification model. We tested the efficiency and accuracy of our model by applying it to the power demand forecasting in Taiwan. Experimental results demonstrate the new method has obviously a higher prediction accuracy than the general model.

  2. Grey Theory Based Vibration Prediction for Steam Turbines

    Institute of Scientific and Technical Information of China (English)

    LIANG Lei; SU Leitao; FENG Yongxin; JIANG Dongxiang

    2012-01-01

    The Mechanism of grey prediction method and its application advantages in safety prediction were described.This method was used to predict the vibration amplitude within the coming 6 hours for a steam turbine.Moreover,the prediction results were examined using correlation degree and posterior error.Results indicated that,this grey prediction method had small posterior error and got a grade Ⅰ accuracy.We can foreknow the variation trend of vibration amplitude of the steam turbine through this method,so as to take timely countermeasures.Therefore,the operation safety of the power unit was improved.

  3. Grey systems for intelligent sensors and information processing

    Institute of Scientific and Technical Information of China (English)

    Chen Chunlin; Dong Daoyi; Chen Zonghai; Wang Haibo

    2008-01-01

    In a measurement system,new representation methods are necessary to maintain the uncertainty and to supply more powerful ability for reasoning and transformation between numerical system and symbolic system.A grey measurement system is discussed from the point of view of intelligent sensors and incomplete information processing compared with a numerical and symbolized mea8urement system.The methods of grey representation and information processing are proposed for data collection and reasoning.As a case study,multi-ultrasonic sensor systems are demonstrated to verify the effectiveness of the proposed methods.

  4. Thermal Error Modelling of the Spindle Using Neurofuzzy Systems

    OpenAIRE

    Jingan Feng; Xiaoqi Tang; Yanlei Li; Bao Song

    2016-01-01

    This paper proposes a new combined model to predict the spindle deformation, which combines the grey models and the ANFIS (adaptive neurofuzzy inference system) model. The grey models are used to preprocess the original data, and the ANFIS model is used to adjust the combined model. The outputs of the grey models are used as the inputs of the ANFIS model to train the model. To evaluate the performance of the combined model, an experiment is implemented. Three Pt100 thermal resistances are use...

  5. Multiobjective Optimization of ELID Grinding Process Using Grey Relational Analysis Coupled with Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    S. Prabhu

    2014-06-01

    Full Text Available Carbon nanotube (CNT mixed grinding wheel has been used in the electrolytic in-process dressing (ELID grinding process to analyze the surface characteristics of AISI D2 Tool steel material. CNT grinding wheel is having an excellent thermal conductivity and good mechanical property which is used to improve the surface finish of the work piece. The multiobjective optimization of grey relational analysis coupled with principal component analysis has been used to optimize the process parameters of ELID grinding process. Based on the Taguchi design of experiments, an L9 orthogonal array table was chosen for the experiments. The confirmation experiment verifies the proposed that grey-based Taguchi method has the ability to find out the optimal process parameters with multiple quality characteristics of surface roughness and metal removal rate. Analysis of variance (ANOVA has been used to verify and validate the model. Empirical model for the prediction of output parameters has been developed using regression analysis and the results were compared for with and without using CNT grinding wheel in ELID grinding process.

  6. Study on Application of Grey Prediction Model in Superalloy MAR-247 Machining

    Directory of Open Access Journals (Sweden)

    Chen Shao-Hsien

    2015-01-01

    Full Text Available Superalloy MAR-247 is mainly applied in the space industry and die industry. With its characteristics of mechanical property, fatigue resistance, and high temperature corrosion resistance, therefore, it is mainly applied in machine parts of high temperature and corrosion resistance, such as turbine blades and rotor of the aeroengine and turbine assembly in the nuclear power plant. However, considering that its properties of high strength, low thermal conductivity, being difficult to soften, and work hardening may reduce the life of cutting-tool and weaken the surface accuracy, the study provided minimizing experiment occurring during milling process for superalloy material. As a statistical approach used to analyse experiment data, this study used GM(1,1 in the grey prediction model to conduct simulation and then predict and analyze its characteristics based on the experimental data, focusing on the tool life and surface accuracy. Moreover, with the superalloy machining parameters of the current effective application improved grey prediction model, it can decrease the errors, extend the tool life, and improve the prediction precision of surface accuracy.

  7. Prediction model of interval grey number based on DGM(1,1)

    Institute of Scientific and Technical Information of China (English)

    Bo Zeng; Sifeng Liu; Naiming Xie

    2010-01-01

    In grey system theory,the studies in the field of grey prediction model are focused on real number sequences,rather than grey number ones.Hereby,a prediction model based on interval grey number sequences is proposed.By mining the geometric features of interval grey number sequences on a two-dimensional surface,all the interval grey numbers are converted into real numbers by means of certain algorithm,and then the prediction model is established based on those real number sequences.The entire process avoids the algebraic operations of grey number,and the prediction problem of interval grey number is usefully solved.Ultimately,through an example's program simulation,the validity and practicability of this novel model are verified.

  8. Measurement and clinical effect of grey matter pathology in multiple sclerosis.

    Science.gov (United States)

    Geurts, Jeroen J G; Calabrese, Massimiliano; Fisher, Elizabeth; Rudick, Richard A

    2012-12-01

    During the past 10 years, the intense involvement of the grey matter of the CNS in the pathology of multiple sclerosis has become evident. On gross inspection, demyelination in the grey matter is rather inconspicuous, and lesions in the grey matter are mostly undetectable with traditional MRI sequences. However, the results of immunohistochemical studies have shown extensive involvement of grey matter, and researchers have developed and applied new MRI acquisition methods as a result. Imaging techniques specifically developed to visualise grey matter lesions indicate early involvement, and image analysis techniques designed to measure the volume of grey matter show progressive loss. Together, these techniques have shown that grey matter pathology is associated with neurological and neuropsychological disability, and the strength of this association exceeds that related to white matter lesions or whole brain atrophy. By focusing on the latest insights into the in-vivo measurement of grey matter lesions and atrophy, we can assess their clinical effects.

  9. Review of the technological approaches for grey water treatment and reuses.

    Science.gov (United States)

    Li, Fangyue; Wichmann, Knut; Otterpohl, Ralf

    2009-05-15

    Based on literature review, a non-potable urban grey water reuse standard is proposed and the treatment alternatives and reuse scheme for grey water reuses are evaluated according to grey water characteristics and the proposed standard. The literature review shows that all types of grey water have good biodegradability. The bathroom and the laundry grey water are deficient in both nitrogen and phosphors. The kitchen grey water has a balanced COD: N: P ratio. The review also reveals that physical processes alone are not sufficient to guarantee an adequate reduction of the organics, nutrients and surfactants. The chemical processes can efficiently remove the suspended solids, organic materials and surfactants in the low strength grey water. The combination of aerobic biological process with physical filtration and disinfection is considered to be the most economical and feasible solution for grey water recycling. The MBR appears to be a very attractive solution in collective urban residential buildings.

  10. Nonlinear fastest growing perturbation and the first kind of predictability

    Institute of Scientific and Technical Information of China (English)

    MU; Mu

    2001-01-01

    [1]Jiao Jiujiu, Grey hydrogeologic system analysis and time series model, Survey Science and Technology (in Chinese), 1987,(10): 39-43.[2]Li Shuwen, Wang Baolai, Xiao Guoqiang, A compound model of grey and periodic scrape and its application in groundwater prediction, Journal of Hebei Institute of Architectural Science & Technology (in Chinese), 1992, (3): 246-251.[3]Wang Qingyin, Li Shuwen, Grey distributed parameter model and groundwater analog, Journal of Hebei Institute of Architectural Science & Technology (in Chinese), 1992, (3): 66-70.[4]Guo Chunqing, Xia Riyuan, Liu Zhenglin, Gray Systematic Theory and Methodological Study of Krast Groundwater Resources Evaluation (in Chinese), Beijing: Geological Publishing House, 1993, 3-60.[5]Wang Qingyin, Liu Kaidi, The Mathematical Method of Grey Systematic Theory and Its Application (in Chinese), Chengdu: Publishing House of Southwestern China University of Communication, 1990, 23-27.[6]Wang Qingyin, Wu Heqing, The concept of grey number and its property, in Proceedings of NAFIPS98, USA, 1998,45-49.[7]Givoli, D., Doukhovni, I., Finite element programming approach for contact problems with geometrical nonlinearity, Computers and Structures, 1996, (8): 31-41.[8]Li Shuwen, Wang Zhiqiang, Wu Qiang, The superiority of storage-centered finite element method in solving seepage problem, Coal Geology and Exploration (in Chinese), 1999, (5): 46-49.

  11. Nonlinear Thermophoresis beyond Local Equilibrium Criterion

    OpenAIRE

    Duhr, Stefan; Braun, Dieter

    2006-01-01

    Thermophoresis (thermodiffusion, Soret effect) moves molecules along thermal gradients. We measure its phenomenological linear drift relation by single particle tracking in convection-free settings. For moderate thermal gradients, drift velocity depends linearly on the gradient. However, for strong thermal gradients, we find a nonlinear dependence of the drift on the applied gradient for large Soret coefficient and particle radius. Interestingly, the onset of the nonlinearity coincides with a...

  12. Comparison of grey matter volume and thickness for analysing cortical changes in chronic schizophrenia: a matter of surface area, grey/white matter intensity contrast, and curvature.

    Science.gov (United States)

    Kong, Li; Herold, Christina J; Zöllner, Frank; Salat, David H; Lässer, Marc M; Schmid, Lena A; Fellhauer, Iven; Thomann, Philipp A; Essig, Marco; Schad, Lothar R; Erickson, Kirk I; Schröder, Johannes

    2015-02-28

    Grey matter volume and cortical thickness are the two most widely used measures for detecting grey matter morphometric changes in various diseases such as schizophrenia. However, these two measures only share partial overlapping regions in identifying morphometric changes. Few studies have investigated the contributions of the potential factors to the differences of grey matter volume and cortical thickness. To investigate this question, 3T magnetic resonance images from 22 patients with schizophrenia and 20 well-matched healthy controls were chosen for analyses. Grey matter volume and cortical thickness were measured by VBM and Freesurfer. Grey matter volume results were then rendered onto the surface template of Freesurfer to compare the differences from cortical thickness in anatomical locations. Discrepancy regions of the grey matter volume and thickness where grey matter volume significantly decreased but without corresponding evidence of cortical thinning involved the rostral middle frontal, precentral, lateral occipital and superior frontal gyri. Subsequent region-of-interest analysis demonstrated that changes in surface area, grey/white matter intensity contrast and curvature accounted for the discrepancies. Our results suggest that the differences between grey matter volume and thickness could be jointly driven by surface area, grey/white matter intensity contrast and curvature.

  13. Modeling and Thermal Analysis of Disc

    Directory of Open Access Journals (Sweden)

    Brake Praveena S

    2014-10-01

    Full Text Available The disc brake is a device used for slowing or stopping the rotation of the vehicle. Number of times using the brake for vehicle leads to heat generation during braking event, such that disc brake undergoes breakage due to high Temperature. Disc brake model is done by CATIA and analysis is done by using ANSYS workbench. The main purpose of this project is to study the Thermal analysis of the Materials for the Aluminum, Grey Cast Iron, HSS M42, and HSS M2. A comparison between the four materials for the Thermal values and material properties obtained from the Thermal analysis low thermal gradient material is preferred. Hence best suitable design, low thermal gradient material Grey cast iron is preferred for the Disc Brakes for better performance.

  14. Nonlinear optomechanical paddle nanocavities

    CERN Document Server

    Kaviani, Hamidreza; Wu, Marcelo; Ghobadi, Roohollah; Barclay, Paul E

    2014-01-01

    A photonic crystal optomechanical system combining strong nonlinear optomechanical coupling, low effective mass and large optical mode spacing is introduced. This nanoscale "paddle nanocavity" device supports mechanical resonances with effective mass of 300--600 fg which couple nonlinearly to co-localized optical modes with a quadratic optomechanical coupling coefficient $g^{(2)} > 2\\pi\\times400$ MHz/nm$^2$, and a two phonon to single photon optomechanical coupling rate $\\Delta \\omega_0 > 2\\pi\\times 16$ Hz. This coupling relies on strong phonon-photon interactions in a structure whose optical mode spectrum is highly non--degenerate. Simulations indicate that nonlinear optomechanical readout of thermally driven motion in these devices should be observable for T $> 50 $ mK, and that measurement of phonon shot noise is achievable.

  15. Practical Nonlinearities

    Science.gov (United States)

    2016-07-01

    Advanced Research Projects Agency (DARPA) Dynamics-Enabled Frequency Sources (DEFYS) program is focused on the convergence of nonlinear dynamics and...Early work in this program has shown that nonlinear dynamics can provide performance advantages. However, the pathway from initial results to...dependent nonlinear stiffness observed in these devices. This work is ongoing, and will continue through the final period of this program . Reference 9

  16. A research on grey numerical imitation and modeling of groundwater seepage system

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on grey set, grey numbers and their operation properties, the grey numerical model of groundwater seepage system was set up for the first time, the whole grey solving method of the model was given and it was proved that the common solving method of the model was only a special case of the grey solving methods. At the same time, the grey solving method was compared widely with common solving method, classical numerical method. The study shows that the grey solving method is better in depicting the procedure of transporting grey data of groundwater system. On the basis of the theoretical study, two basic kinds of cases about groundwater seepage were selected: the prediction of pit yield and the evaluation of groundwater resources on a groundwater basin. In the cases, systematical analyses were made for generalization and greylization of the hydrogeologic conditions, setting up of the grey model, identification and correction of the model as well as its prediction and evaluation. It was pointed out that when the grey numerical model is used to predict pit yield, the upper limit of the “grey band” of groundwater level cannot be higher than planed safe groundwater level, when evaluating the groundwater resource, the lower limit of the “grey band” of groundwater level cannot be lower than controlled level of groundwater.

  17. Characterization and treatment of grey water : option for (re)use

    NARCIS (Netherlands)

    Abu-Ghunmi, L.N.A.H.

    2009-01-01

    Addressing the issues of water shortage and appropriate sanitation in Jordan, domestic grey water treatment receives growing interest. Grey water comprises the domestic wastewater flows excluding waters associated with the toilet. The topics of concern for grey water are its characteristics, treatme

  18. Fos expression in the midbrain periaqueductal grey after trigeminovascular stimulation

    NARCIS (Netherlands)

    Hoskin, KL; Bulmer, DCE; Lasalandra, M; Jonkman, A; Goadsby, PJ

    2001-01-01

    There is an accumulating body of evidence suggesting that the periaqueductal grey (PAG) is involved in the pathophysiology of migraine. Positron emission tomography (PET) studies in humans have shown that the caudal ventrolateral midbrain, encompassing the ventrolateral PAG, has activations during m

  19. On the remote sensing of Hawking grey pulses

    OpenAIRE

    Rosu, H. C.

    1994-01-01

    This is a short note on the black hole remote-sensing problem, i.e., finding out `surface' temperature distributions of various types of small (micron-sized) black holes from the spectral measurements of their Hawking grey pulses. Chen's modified Moebius inverse transform is illustrated in this context

  20. A Grey Box Model for the Hydraulics in a Creek

    DEFF Research Database (Denmark)

    Jonsdottir, Harpa; Jacobsen, Judith L.; Madsen, Henrik

    1998-01-01

    The Saint-Venant equation of mass balance is used to derive a stochastics lumped model, describing the dynamics of a cross-sectional area in a river. The unknown parameters of the model are estimated by combining the physical equation with a set of data, a method known as grey box modelling. The ...

  1. Grey System Forecast for Firing Accuracy of Gun

    Institute of Scientific and Technical Information of China (English)

    CHENG Qi-yue; QIU Wan-hua

    2001-01-01

    In this paper, the system and subsystem forecast models for firing accuracy have been built by means of theory of Grey System Forecast. It has provided a scientific forecasting method for micro-errorcontrol and macro-error-control and improving the firing accuracy.

  2. Laser surface treatment of grey cast iron for automotive applications

    NARCIS (Netherlands)

    Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2005-01-01

    The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast

  3. Laser surface treatment of grey cast iron for automotive applications

    NARCIS (Netherlands)

    Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2005-01-01

    The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast

  4. Modelling prey consumption and switching by UK grey seals

    DEFF Research Database (Denmark)

    Smout, Sophie; Rindorf, Anna; Hammond, Philip S.

    2014-01-01

    Grey seals (Halichoerus grypus) are adaptable generalist predatorswhose diet includes commercial fish species such as cod. Consumption by the seals may reduce the size of some fish stocks or have an adverse effect on stock recovery programmes, especially because predation may trap sparse prey pop...

  5. Distribution and Growth of Grey Triggerfish, Balistes capriscus ...

    African Journals Online (AJOL)

    Sam Eshun

    fitting the observed length-at-age data to the standard form of von Bertalanffy ... growth and distribution of grey triggerfish in the Western Gulf of Guinea had not ... were obtained: (i) the first section just above the condyle (the enlarged base.

  6. Grey-scale morphology based on fuzzy logic

    NARCIS (Netherlands)

    Deng, T.-Q.; Heijmans, H.J.A.M.

    2000-01-01

    There exist several methods to extend binary morphology to grey-scale images. One of these methods is based on fuzzy logic and fuzzy set theory. Another approach starts from the complete lattice framework for morphology and the theory of adjunctions. In this paper, both approaches are combined. The

  7. Organic matter and heavy metals in grey-water sludge

    African Journals Online (AJOL)

    2010-01-08

    Jan 8, 2010 ... The OUR results indicate that the grey-water biological sludge contains an equivalent amount of readily ... subjected to treatment in municipal wastewater treatment plants (WWTP) ... (Cd), nickel (Ni) and lead (Pb) as requested in the European ... WWTP receives both domestic and industrial wastewater and.

  8. The Grey Nomad Phenomenon: Changing the Script of Aging

    Science.gov (United States)

    Onyx, Jenny; Leonard, Rosemary

    2007-01-01

    This article explores a relatively new and little understood phenomenon, that of the Australian Grey Nomads. Every year increasing numbers of older Australians take to the road. This article explores the phenomenon both empirically and theoretically. A grounded approach is used by which the experience is explored from an ethnographic account…

  9. A Grey Box Model for the Hydraulics in a Creek

    DEFF Research Database (Denmark)

    Jonsdottir, Harpa; Jacobsen, Judith L.; Madsen, Henrik

    1998-01-01

    The Saint-Venant equation of mass balance is used to derive a stochastics lumped model, describing the dynamics of a cross-sectional area in a river. The unknown parameters of the model are estimated by combining the physical equation with a set of data, a method known as grey box modelling...

  10. Global population structure and demographic history of the grey seal

    DEFF Research Database (Denmark)

    Klimova, A.; Phillips, C. D.; Fietz, Katharina;

    2014-01-01

    a little over 10 000 years ago, consistent with the last proposed isolation of the Baltic Sea. Approximate Bayesian computation also identified genetic signals consistent with postglacial population expansion across much of the species range, suggesting that grey seals are highly responsive to changes...

  11. Experimental Grey Box Model Identification of an Active Gas Bearing

    DEFF Research Database (Denmark)

    Theisen, Lukas Roy Svane; Pierart Vásquez, Fabián Gonzalo; Niemann, Hans Henrik;

    2014-01-01

    in a dynamic model of an active gas bearing and subsequent control loop design. A grey box model is determined based on experiments where piezo actuated valves are used to perturb the journal and hence excite the rotor-bearing system. Such modelling from actuator to output is shown to effciently support...

  12. Nonlinear oscillations

    CERN Document Server

    Nayfeh, Ali Hasan

    1995-01-01

    Nonlinear Oscillations is a self-contained and thorough treatment of the vigorous research that has occurred in nonlinear mechanics since 1970. The book begins with fundamental concepts and techniques of analysis and progresses through recent developments and provides an overview that abstracts and introduces main nonlinear phenomena. It treats systems having a single degree of freedom, introducing basic concepts and analytical methods, and extends concepts and methods to systems having degrees of freedom. Most of this material cannot be found in any other text. Nonlinear Oscillations uses sim

  13. Nonlinear Science

    CERN Document Server

    Yoshida, Zensho

    2010-01-01

    This book gives a general, basic understanding of the mathematical structure "nonlinearity" that lies in the depths of complex systems. Analyzing the heterogeneity that the prefix "non" represents with respect to notions such as the linear space, integrability and scale hierarchy, "nonlinear science" is explained as a challenge of deconstruction of the modern sciences. This book is not a technical guide to teach mathematical tools of nonlinear analysis, nor a zoology of so-called nonlinear phenomena. By critically analyzing the structure of linear theories, and cl

  14. Nonlinear analysis

    CERN Document Server

    Nanda, Sudarsan

    2013-01-01

    "Nonlinear analysis" presents recent developments in calculus in Banach space, convex sets, convex functions, best approximation, fixed point theorems, nonlinear operators, variational inequality, complementary problem and semi-inner-product spaces. Nonlinear Analysis has become important and useful in the present days because many real world problems are nonlinear, nonconvex and nonsmooth in nature. Although basic concepts have been presented here but many results presented have not appeared in any book till now. The book could be used as a text for graduate students and also it will be useful for researchers working in this field.

  15. Matrix Thermalization

    CERN Document Server

    Craps, Ben; Nguyen, Kévin

    2016-01-01

    Matrix quantum mechanics offers an attractive environment for discussing gravitational holography, in which both sides of the holographic duality are well-defined. Similarly to higher-dimensional implementations of holography, collapsing shell solutions in the gravitational bulk correspond in this setting to thermalization processes in the dual quantum mechanical theory. We construct an explicit, fully nonlinear supergravity solution describing a generic collapsing dilaton shell, specify the holographic renormalization prescriptions necessary for computing the relevant boundary observables, and apply them to evaluating thermalizing two-point correlation functions in the dual matrix theory.

  16. Dynamic Modeling of Steam Condenser and Design of PI Controller Based on Grey Wolf Optimizer

    Directory of Open Access Journals (Sweden)

    Shu-Xia Li

    2015-01-01

    Full Text Available Shell-and-tube condenser is a heat exchanger for cooling steam with high temperature and pressure, which is one of the main kinds of heat exchange equipment in thermal, nuclear, and marine power plant. Based on the lumped parameter modeling method, the dynamic mathematical model of the simplified steam condenser is established. Then, the pressure PI control system of steam condenser based on the Matlab/Simulink simulation platform is designed. In order to obtain better performance, a new metaheuristic intelligent algorithm, grey wolf optimizer (GWO, is used to realize the fine-tuning of PI controller parameters. On the other hand, the Z-N engineering tuning method, genetic algorithm, and particle swarm algorithm are adopted for tuning PI controller parameters and compared with GWO algorithm. Simulation results show that GWO algorithm has better control performance than other four algorithms.

  17. Blue and grey water footprint of textile industry in China.

    Science.gov (United States)

    Wang, Laili; Ding, Xuemei; Wu, Xiongying

    2013-01-01

    Water footprint (WF) is a newly developed idea that indicates impacts of freshwater appropriation and wastewater discharge. The textile industry is one of the oldest, longest and most complicated industrial chains in the world's manufacturing industries. However, the textile industry is also water intensive. In this paper, we applied a bottom-up approach to estimate the direct blue water footprint (WFdir,blue) and direct grey water footprint (WFdir,grey) of China's textile industry at sector level based on WF methodology. The results showed that WFdir,blue of China's textile industry had an increasing trend from 2001 to 2010. The annual WFdir,blue surpassed 0.92 Gm(3)/yr (giga cubic meter a year) since 2004 and rose to peak value of 1.09 Gm(3)/yr in 2007. The original and residuary WFdir,grey (both were calculated based on the concentration of chemical oxygen demand (CODCr)) of China's textile industry had a similar variation trend with that of WFdir,blue. Among the three sub-sectors of China's textile industry, the manufacture of textiles sector's annual WFdir,blue and WFdir,grey were much larger than those of the manufacture of textile wearing apparel, footware and caps sector and the manufacture of chemical fibers sector. The intensities of WFdir,blue and WF(res)dir,grey of China's textile industry were year by year decreasing through the efforts of issuing restriction policies on freshwater use and wastewater generation and discharge, and popularization of water saving and wastewater treatment technologies.

  18. Nonlinear plasmonics at high temperatures

    Directory of Open Access Journals (Sweden)

    Sivan Yonatan

    2017-01-01

    Full Text Available We solve the Maxwell and heat equations self-consistently for metal nanoparticles under intense continuous wave (CW illumination. Unlike previous studies, we rely on experimentally-measured data for metal permittivity for increasing temperature and for the visible spectral range. We show that the thermal nonlinearity of the metal can lead to substantial deviations from the predictions of the linear model for the temperature and field distribution and, thus, can explain qualitatively the strong nonlinear scattering from such configurations observed experimentally. We also show that the incompleteness of existing data of the temperature dependence of the thermal properties of the system prevents reaching a quantitative agreement between the measured and calculated scattering data. This modeling approach is essential for the identification of the underlying physical mechanism responsible for the thermo-optical nonlinearity of the metal and should be adopted in all applications of high-temperature nonlinear plasmonics, especially for refractory metals, for both CW and pulsed illumination.

  19. Nonlinear plasmonics at high temperatures

    Science.gov (United States)

    Sivan, Yonatan; Chu, Shi-Wei

    2017-01-01

    We solve the Maxwell and heat equations self-consistently for metal nanoparticles under intense continuous wave (CW) illumination. Unlike previous studies, we rely on experimentally-measured data for metal permittivity for increasing temperature and for the visible spectral range. We show that the thermal nonlinearity of the metal can lead to substantial deviations from the predictions of the linear model for the temperature and field distribution and, thus, can explain qualitatively the strong nonlinear scattering from such configurations observed experimentally. We also show that the incompleteness of existing data of the temperature dependence of the thermal properties of the system prevents reaching a quantitative agreement between the measured and calculated scattering data. This modeling approach is essential for the identification of the underlying physical mechanism responsible for the thermo-optical nonlinearity of the metal and should be adopted in all applications of high-temperature nonlinear plasmonics, especially for refractory metals, for both CW and pulsed illumination.

  20. Real-time process optimization based on grey-box neural models

    Directory of Open Access Journals (Sweden)

    F. A. Cubillos

    2007-09-01

    Full Text Available This paper investigates the feasibility of using grey-box neural models (GNM in Real Time Optimization (RTO. These models are based on a suitable combination of fundamental conservation laws and neural networks, being used in at least two different ways: to complement available phenomenological knowledge with empirical information, or to reduce dimensionality of complex rigorous physical models. We have observed that the benefits of using these simple adaptable models are counteracted by some difficulties associated with the solution of the optimization problem. Nonlinear Programming (NLP algorithms failed in finding the global optimum due to the fact that neural networks can introduce multimodal objective functions. One alternative considered to solve this problem was the use of some kind of evolutionary algorithms, like Genetic Algorithms (GA. Although these algorithms produced better results in terms of finding the appropriate region, they took long periods of time to reach the global optimum. It was found that a combination of genetic and nonlinear programming algorithms can be use to fast obtain the optimum solution. The proposed approach was applied to the Williams-Otto reactor, considering three different GNM models of increasing complexity. Results demonstrated that the use of GNM models and mixed GA/NLP optimization algorithms is a promissory approach for solving dynamic RTO problems.

  1. Quantitative grey matter histological measures do not correlate with grey matter probability values from in vivo MRI in the temporal lobe

    OpenAIRE

    Eriksson, S.H.; Free, S. L.; Thom, M; Symms, M. R.; Martinian, L.; Duncan, J.S.; Sisodiya, S M

    2009-01-01

    Voxel-based morphometry (VBM) is commonly used to study systematic differences in brain morphology from patients with various disorders, usually by comparisons with control subjects. It has often been suggested, however, that VBM is also sensitive to variations in composition in grey matter. The nature of the grey matter changes identified with VBM is still poorly understood. The aim of the current study was to determine whether grey matter histopathological measurements of neuronal tissue or...

  2. Numerical Solution of Inverse Radiative-Conductive Transient Heat Transfer Problem in a Grey Participating Medium

    Science.gov (United States)

    Zmywaczyk, J.; Koniorczyk, P.

    2009-08-01

    The problem of simultaneous identification of the thermal conductivity Λ(T) and the asymmetry parameter g of the Henyey-Greenstein scattering phase function is under consideration. A one-dimensional configuration in a grey participating medium with respect to silica fibers for which the thermophysical and optical properties are known from the literature is accepted. To find the unknown parameters, it is assumed that the thermal conductivity Λ(T) may be represented in a base of functions {1, T, T 2, . . .,T K } so the inverse problem can be applied to determine a set of coefficients {Λ0, Λ1, . . ., Λ K ; g}. The solution of the inverse problem is based on minimization of the ordinary squared differences between the measured and model temperatures. The measured temperatures are considered known. Temperature responses measured or theoretically generated at several different distances from the heat source along an x axis of the specimen set are known as a result of the numerical solution of the transient coupled heat transfer in a grey participating medium. An implicit finite volume method (FVM) is used for handling the energy equation, while a finite difference method (FDM) is applied to find the sensitivity coefficients with respect to the unknown set of coefficients. There are free parameters in a model, so these parameters are changed during an iteration process used by the fitting procedure. The Levenberg- Marquardt fitting procedure is iteratively searching for best fit of these parameters. The source term in the governing conservation-of-energy equation taking into account absorption, emission, and scattering of radiation is calculated by means of a discrete ordinate method together with an FDM while the scattering phase function approximated by the Henyey-Greenstein function is expanded in a series of Legendre polynomials with coefficients {c l } = (2l + 1)g l . The numerical procedure proposed here also allows consideration of some cases of coupled heat

  3. Performance Analysis of Data-Driven and Model-Based Control Strategies Applied to a Thermal Unit Model

    Directory of Open Access Journals (Sweden)

    Cihan Turhan

    2017-01-01

    Full Text Available The paper presents the design and the implementation of different advanced control strategies that are applied to a nonlinear model of a thermal unit. A data-driven grey-box identification approach provided the physically–meaningful nonlinear continuous-time model, which represents the benchmark exploited in this work. The control problem of this thermal unit is important, since it constitutes the key element of passive air conditioning systems. The advanced control schemes analysed in this paper are used to regulate the outflow air temperature of the thermal unit by exploiting the inflow air speed, whilst the inflow air temperature is considered as an external disturbance. The reliability and robustness issues of the suggested control methodologies are verified with a Monte Carlo (MC analysis for simulating modelling uncertainty, disturbance and measurement errors. The achieved results serve to demonstrate the effectiveness and the viable application of the suggested control solutions to air conditioning systems. The benchmark model represents one of the key issues of this study, which is exploited for benchmarking different model-based and data-driven advanced control methodologies through extensive simulations. Moreover, this work highlights the main features of the proposed control schemes, while providing practitioners and heating, ventilating and air conditioning engineers with tools to design robust control strategies for air conditioning systems.

  4. Terahertz Nonlinearity in Graphene Plasmons

    CERN Document Server

    Jadidi, Mohammad M; Winnerl, Stephan; Sushkov, Andrei B; Drew, H Dennis; Murphy, Thomas E; Mittendorff, Martin

    2015-01-01

    Sub-wavelength graphene structures support localized plasmonic resonances in the terahertz and mid-infrared spectral regimes. The strong field confinement at the resonant frequency is predicted to significantly enhance the light-graphene interaction, which could enable nonlinear optics at low intensity in atomically thin, sub-wavelength devices. To date, the nonlinear response of graphene plasmons and their energy loss dynamics have not been experimentally studied. We measure and theoretically model the terahertz nonlinear response and energy relaxation dynamics of plasmons in graphene nanoribbons. We employ a THz pump-THz probe technique at the plasmon frequency and observe a strong saturation of plasmon absorption followed by a 10 ps relaxation time. The observed nonlinearity is enhanced by two orders of magnitude compared to unpatterned graphene with no plasmon resonance. We further present a thermal model for the nonlinear plasmonic absorption that supports the experimental results.

  5. Prediction Model of Interval Grey Numbers with a Real Parameter and Its Application

    Directory of Open Access Journals (Sweden)

    Bo Zeng

    2014-01-01

    Full Text Available Grey prediction models have become common methods which are widely employed to solve the problems with “small examples and poor information.” However, modeling objects of existing grey prediction models are limited to the homogenous data sequences which only contain the same data type. This paper studies the methodology of building prediction models of interval grey numbers that are grey heterogeneous data sequence, with a real parameter. Firstly, the position of the real parameter in an interval grey number sequence is discussed, and the real number is expanded into an interval grey number by adopting the method of grey generation. On this basis, a prediction model of interval grey number with a real parameter is deduced and built. Finally, this novel model is successfully applied to forecast the concentration of organic pollutant DDT in the atmosphere. The analysis and research results in this paper extend the object of grey prediction from homogenous data sequence to grey heterogeneous data sequence. Those research findings are of positive significance in terms of enriching and improving the theory system of grey prediction models.

  6. Novel combinatorial algorithm for the problems of fuzzy grey multi-attribute group decision making

    Institute of Scientific and Technical Information of China (English)

    Rao Congjun; Xiao Xinping; Peng Jin

    2007-01-01

    To study the fuzzy and grey information in the problems of multi-attribute group decision making, the basic concepts of both fuzzy grey numbers and grey interval numbers are given firstly, then a new model of fuzzy grey multi-attribute group decision making based on the theories of fuzzy mathematics and grey system is presented. Furthermore, the grey interval relative degree and deviation degree is defined, and both the optimistic algorithm of the grey interval relational degree and the algorithm of deviation degree minimization for solving this new model are also given. Finally, a decision making example to demonstrate the feasibility and rationality of this new method is given, and the results by using these two algorithms are uniform.

  7. Connecting Archaeological Data and Grey Literature via Semantic Cross Search

    Directory of Open Access Journals (Sweden)

    Douglas Tudhope

    2011-07-01

    Full Text Available Differing terminology and database structure hinders meaningful cross search of excavation datasets. Matching free text grey literature reports with datasets poses yet more challenges. Conventional search techniques are unable to cross search between archaeological datasets and Web-based grey literature. Results are reported from two AHRC funded research projects that investigated the use of semantic techniques to link digital archive databases, vocabularies and associated grey literature. STAR (Semantic Technologies for Archaeological Resources was a collaboration between the University of Glamorgan, Hypermedia Research Unit and English Heritage (EH. The main outcome is a research Demonstrator (available online, which cross searches over excavation datasets from different database schemas, including Raunds Roman, Raunds Prehistoric, Museum of London, Silchester Roman and Stanwick sampling. The system additionally cross searches over an extract of excavation reports from the OASIS index of grey literature, operated by the Archaeology Data Service (ADS. A conceptual framework provided by the CIDOC Conceptual Reference Model (CRM integrates the different database structures and the metadata automatically generated from the OASIS reports by natural language processing techniques. The methods employed for extracting semantic RDF representations from the datasets and the information extraction from grey literature are described. The STELLAR project provides freely available tools to reduce the costs of mapping and extracting data to semantic search systems such as the Demonstrator and to linked data representation generally. Detailed use scenarios (and a screen capture video provide a basis for a discussion of key issues, including cost-benefits, ontology modelling, mapping, terminology control, semantic implementation and information extraction issues. The scenarios show that semantic interoperability can be achieved by mapping and extracting

  8. Nonlinear Reconstruction

    CERN Document Server

    Zhu, Hong-Ming; Pen, Ue-Li; Chen, Xuelei; Yu, Hao-Ran

    2016-01-01

    We present a direct approach to non-parametrically reconstruct the linear density field from an observed non-linear map. We solve for the unique displacement potential consistent with the non-linear density and positive definite coordinate transformation using a multigrid algorithm. We show that we recover the linear initial conditions up to $k\\sim 1\\ h/\\mathrm{Mpc}$ with minimal computational cost. This reconstruction approach generalizes the linear displacement theory to fully non-linear fields, potentially substantially expanding the BAO and RSD information content of dense large scale structure surveys, including for example SDSS main sample and 21cm intensity mapping.

  9. Nonlinear optics

    CERN Document Server

    Boyd, Robert W

    2013-01-01

    Nonlinear Optics is an advanced textbook for courses dealing with nonlinear optics, quantum electronics, laser physics, contemporary and quantum optics, and electrooptics. Its pedagogical emphasis is on fundamentals rather than particular, transitory applications. As a result, this textbook will have lasting appeal to a wide audience of electrical engineering, physics, and optics students, as well as those in related fields such as materials science and chemistry.Key Features* The origin of optical nonlinearities, including dependence on the polarization of light* A detailed treatment of the q

  10. A non-grey analytical model for irradiated atmospheres. I. Derivation

    Science.gov (United States)

    Parmentier, Vivien; Guillot, Tristan

    2014-02-01

    Context. Semi-grey atmospheric models (with one opacity for the visible and one opacity for the infrared) are useful for understanding the global structure of irradiated atmospheres, their dynamics, and the interior structure and evolution of planets, brown dwarfs, and stars. When compared to direct numerical radiative transfer calculations for irradiated exoplanets, however, these models systematically overestimate the temperatures at low optical depths, independently of the opacity parameters. Aims: We investigate why semi-grey models fail at low optical depths and provide a more accurate approximation to the atmospheric structure by accounting for the variable opacity in the infrared. Methods: Using the Eddington approximation, we derive an analytical model to account for lines and/or bands in the infrared. Four parameters (instead of two for the semi-grey models) are used: a visible opacity (κv), two infrared opacities, (κ1 and κ2), and β (the fraction of the energy in the beam with opacities κ1). We consider that the atmosphere receives an incident irradiation in the visible with an effective temperature Tirr and at an angle μ∗, and that it is heated from below with an effective temperature Tint. Results: Our non-grey, irradiated line model is found to provide a range of temperatures that is consistent with that obtained by numerical calculations. We find that if the stellar flux is absorbed at optical depth larger than τlim = (κR/κ1κ2)(κRκP/3)1/2, it is mainly transported by the channel of lowest opacity whereas if it is absorbed at τ ≳ τlim it is mainly transported by the channel of highest opacity, independently of the spectral width of those channels. For low values of β (expected when lines are dominant), we find that the non-grey effects significantly cool the upper atmosphere. However, for β ≳ 1/2 (appropriate in the presence of bands with a wavelength-dependence smaller than or comparable to the width of the Planck function), we

  11. Improvement of CCME WQI using grey relational method

    Science.gov (United States)

    Yan, Feng; Qiao, Danying; Qian, Bao; Ma, Lin; Xing, Xigang; Zhang, You; Wang, Xiaogang

    2016-12-01

    The conventional CCME WQI ignores the uncertainties in aquatic environment, which may lead to biases and abrupt changes in evaluation results. To overcome this shortcoming, this study improves the calculation of CCME WQI using trapezoid grey relational degree method, a model dealing with uncertainties introduced by incomplete information. Compared with the conventional CCME WQI, the grey CCME WQI has a stricter calculation method in synthetic evaluation and a better capacity in water quality warning. The water quality of New Tongyang Canal is evaluated and the result shows that its environment deteriorates with the increasing rainfall and improves with the decreasing precipitation. To decrease its environmental risk, it is suggested to reduce the nutrients in agricultural runoff and the oxygen-consuming pollutants in urban runoff in the rainy season.

  12. Application of Grey System Theory in Design For Cost (DFC)

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-chuan; FANG Ming-lun

    2003-01-01

    Design For Cost (DFC) is a branch of Design For X (DFX). In this paper, we defined DFC as a design method that analyzed and evaluated the product's life cycle cost ( LCC ) , then modified the design to reduce the LCC. Nowadays it is a very difficult thing to obtain LCC data in China or in developing countries. Statistical methods can not be used because available LCC data are few. In order to solve this problem, we used grey system theory. Then relations of cost factors were analyzed in LCC using grey relevant methods, and a GM( 1,1 ) model between design parameters and LCC was established. Using this model, we can estimate and control LCC by changing design parameters at the beginning of the design stage.

  13. A New Method for Grey Forecasting Model Group

    Institute of Scientific and Technical Information of China (English)

    李峰; 王仲东; 宋中民

    2002-01-01

    In order to describe the characteristics of some systems, such as the process of economic and product forecasting, a lot of discrete data may be used. Although they are discrete, the inside law can be-founded by some methods. For a series that the discrete degree is large and the integrated tendency is ascending, a new method for grey forecasting model group is given by the grey system theory. The method is that it firstly transforms original data, chooses some clique values and divides original data into groups by different clique values; then, it establishes non-equigap GM(1, 1) model for different groups and searches forecasting area of original data by the solution of model. At the end of the paper, the result of reliability of forecasting value is obtained. It is shown that the method is feasible.

  14. Product and process innovation of grey cast iron brake discs

    Energy Technology Data Exchange (ETDEWEB)

    Schorn, M. [Brembo S.P.A. (Italy)

    2006-07-01

    The brake disc out of grey cast iron often seems to be playing the role of the ''underdog'' in the technical examinations of the entire brake system. This is also reflected by the 25 year history of the {mu}-club. In a total of 93 presentations in those 25 years, only 3 were related to the topic of grey cast iron discs. This is not a correct relation to the importance of this component within the brake system. The disc, although per definition with a lower specific load than the pad, has the major task to store and dissipate the heat in which the kinetic energy of the vehicle is transformed. The disc also has a significant effect on NVH behaviour, particularly in the low frequency range. It also has a permanent fight with its weight as an unsprung mass. (orig.)

  15. Chemical composition of lipophilic extractives from grey alder (Alnus incana

    Directory of Open Access Journals (Sweden)

    Oskars Bikovens

    2013-02-01

    Full Text Available The chemical composition of the lipophilic extractives in the hexane extracts from grey alder bark, knotwood, and cones has been investigated by gas chromatography and gas chromatography-mass spectrometry. The efficiency of two extraction methods was compared. The highest amount of lipophilic extractives (about 9% of o.d. material was observed in grey alder cone, while the lowest (about 3% was found in knotwood. The three different morphological parts of alder showed significant differences not only in the content but also in composition of extractives, namely fatty acids, triglycerides, and triterpenes. The main identified compounds were triterpenoids (lupen-3-one, lupeol, betulone, betulinol, and betulinic acid in bark, and triglycerides in cones. The major group in knotwood was free fatty acids (mainly linoleic acid, 18:2.

  16. Thinlip grey mullet Liza ramada (Mugilidae caught in a

    Directory of Open Access Journals (Sweden)

    Bror Jonsson

    2009-12-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 Two individuals of thinlip grey mullet Liza ramada were collected in a southern Norwegian brook (58° 22’ N, 8° 37’ E on 12th September 2007. The fish were 8.7 and 9.0 cm in total length, 6 and 7 g in total mass, and most probably in their first year of life. The nearest known spawning area of the species is south of the English Channel, meaning that they had probably moved at least 900 km across the North Sea during their first growth season. To our knowledge, this is the first published observation of the catadromous thinlip grey mullet from a Scandinavian freshwater course.

  17. Grey System Judgment on Reliability of Mechanical Equipment

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Grey system theory was applied in reliability analysis of mechanical equip-ment. It is a new theory and method in reliability engineering of mechanical engineering of mechanical equipment. Through the Grey forecast of reliability parameters and the relia-bility forecast of parts and systems, decisions were made in the real operative state of e-quipment in real time. It replaced the old method that required mathematics and physical statistics in a large base of test data to obtain a pre-check, and it was used in a practical problem. Because of applying the data of practical operation state in real time, it could much more approach the real condition of equipment; it was applied to guide the procedure and had rather considerable economic and social benefits.

  18. Investigation of the chip formation of austempered grey iron

    Science.gov (United States)

    Lung, S.; Klocke, F.; Döbbeler, B.; Krick, E.

    2016-10-01

    By a heat treatment process the strength and thus the field of applications of Grey Cast Iron (GI) can be increased to a range which is comparable to Compacted Graphite Iron (CGI). The microstructure of the resulting material consists of austenite and acicular ferrite. This material is named Austempered Grey Iron (AGI). Until now the material has not yet made its way to widespread use, due to the unknown machinability. For an economical use the machinability of the material must be at least at the level of CGI. This work deals with the chip formation, as an evaluation criterion for the machinability and represents a first step towards a comprehensive assessment of machining of AGI materials. To investigate the chip formation chip roots of three different AGI grades, a GI and a CGI were produced in a turning process. The chip roots were prepared to analyse the deformation of the microstructure during the chip formation.

  19. Studies on Growth, Spectral, Thermal, Mechanical and Optical Properties of 4-Bromoanilinium 4-Methylbenzenesulfonate Crystal: A Third Order Nonlinear Optical Material

    OpenAIRE

    Sivakumar,Pillukuruchi Kailasam; Kumar,Saravana; Kumar,Rangasamy Mohan; Kanagadurai,Ramajayam; Sagadevan,Suresh

    2016-01-01

    Abstract 4-Bromoanilinium 4-methylbenzenesulfonate (4BPTS) single crystal was successfully grown from ethanol by slow evaporation method at room temperature. The structure of grown crystal was confirmed by single crystal X-ray diffraction studies. The presence of functional groups of grown crystal was confirmed by the Fourier transform infrared spectroscopy (FTIR) spectral analysis. UV-Visible absorption study was performed on the grown crystal to determine the cut-off wavelength. The thermal...

  20. Grey Prediction Based Software Stage-Effort Estimation

    Institute of Scientific and Technical Information of China (English)

    WANG Yong; SONG Qinbao; SHEN Junyi

    2007-01-01

    The software stage-effort estimation can be used to dynamically adjust software project schedule, further to help make the project finished on budget. This paper presents a grey model Verhulst based method for stage-effort estimation during software development process, a bias correction technology was used to improve the estimation accuracy. The proposed method was evaluated with a large-scale industrial software engineering database. The results are very encouraging and indicate the method has considerable potential.

  1. Botrytis cinerea: Causal agent of small fruit grey mould

    OpenAIRE

    Tanović, Brankica

    2012-01-01

    Small fruits growing in Serbia is an important and profitable business. However, disease causal agents, pests and weeds often threaten production profitability. A common problem in production of most important small fruit species is a polyfagous, phytopathogenic fungal species Botrytis cinerea, the causal agent of grey mould disease of fruits. Present knowledge on the causal agent, its morphological, ecological and epidemiological characteristics are systematized in the paper. Infection proce...

  2. Lorenz Wind Disturbance Model Based on Grey Generated Components

    OpenAIRE

    Yagang Zhang; Jingyun Yang; Kangcheng Wang; Yinding Wang

    2014-01-01

    In order to meet the needs of wind speed prediction in wind farms, we consider the influence of random atmospheric disturbances on wind variations. Considering a simplified fluid convection mode, a Lorenz system can be employed as an atmospheric disturbance model. Here Lorenz disturbance is defined as the European norm of the solutions of the Lorenz equation. Grey generating and accumulated generating models are employed to explore the relationship between wind speed and its related disturban...

  3. Synthesis and characterization of thermally stable second-order nonlinear optical side-chain polyimides containing thiazole and benzothiazole push-pull chromophores

    Science.gov (United States)

    Tambe, S. M.; Kittur, A. A.; Inamdar, S. R.; Mitchell, G. R.; Kariduraganavar, M. Y.

    2009-04-01

    Push-pull nonlinear optical (NLO) chromophores containing thiazole and benzothiazole acceptors were synthesized and characterized. Using these chromophores a series of second-order NLO polyimides were successfully prepared from 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), pyromellitic dianhydride (PMDA) and 3,3'4,4'-benzophenone tetracarboxylic dianhydride (BTDA) by a standard condensation polymerization technique. These polyimides exhibit high glass transition temperatures ranging from 160 to 188 °C. UV-vis spectrum of polyimide exhibited a slight blue shift and decreases in absorption due to birefringence. From the order parameters, it was found that chromophores were aligned effectively. Using in situ poling and temperature ramping technique, the optical temperatures for corona poling were obtained. It was found that the optimal temperatures of polyimides approach their glass transition temperatures. These polyimides demonstrate relatively large d33 values range between 35.15 and 45.20 pm/V at 532 nm.

  4. Nonlinear optimization

    CERN Document Server

    Ruszczynski, Andrzej

    2011-01-01

    Optimization is one of the most important areas of modern applied mathematics, with applications in fields from engineering and economics to finance, statistics, management science, and medicine. While many books have addressed its various aspects, Nonlinear Optimization is the first comprehensive treatment that will allow graduate students and researchers to understand its modern ideas, principles, and methods within a reasonable time, but without sacrificing mathematical precision. Andrzej Ruszczynski, a leading expert in the optimization of nonlinear stochastic systems, integrates t

  5. Hybrid grey model to forecast monitoring series with seasonality

    Institute of Scientific and Technical Information of China (English)

    WANG Qi-jie; LIAO Xin-hao; ZHOU Yong-hong; ZOU Zheng-rong; ZHU Jian-jun; PENG Yue

    2005-01-01

    The grey forecasting model has been successfully applied to many fields. However, the precision of GM(1,1) model is not high. In order to remove the seasonal fluctuations in monitoring series before building GM(1,1) model, the forecasting series of GM(1,1) was built, and an inverse process was used to resume the seasonal fluctuations. Two deseasonalization methods were presented , i.e., seasonal index-based deseasonalization and standard normal distribution-based deseasonalization. They were combined with the GM(1,1) model to form hybrid grey models. A simple but practical method to further improve the forecasting results was also suggested. For comparison, a conventional periodic function model was investigated. The concept and algorithms were tested with four years monthly monitoring data. The results show that on the whole the seasonal index-GM(1,1) model outperform the conventional periodic function model and the conventional periodic function model outperform the SND-GM(1,1) model. The mean absolute error and mean square error of seasonal index-GM(1,1) are 30.69% and 54.53% smaller than that of conventional periodic function model, respectively. The high accuracy, straightforward and easy implementation natures of the proposed hybrid seasonal index-grey model make it a powerful analysis technique for seasonal monitoring series.

  6. Novel foods: an explorative study into their grey area.

    Science.gov (United States)

    Verhagen, Hans; te Boekhorst, Janneke; Kamps, Lisette; van Lieshout, Marten J; Ploeger, Hilko; Verreth, Daphne; Salminen, Seppo; van Loveren, Henk

    2009-05-01

    European Union Regulation 258/97 defines novel foods as food products and food ingredients that have not been consumed to a significant degree in the European Union before May 1997. However, there are new foods that for some reason are not considered as novel foods, though we think that safety of these products is not always a priori established. We defined a 'grey area' which consists of such foods, and the present paper intends to raise awareness of this 'grey area' of unidentified novel foods. The grey area of novel foods is divided into two categories: (1) food products or ingredients for which the current Regulation leaves too much space for different interpretations and (2) food products or ingredients that are not novel according to the current Regulation, because the current Regulation contains gaps. These categories are illustrated by means of products already on the market in The Netherlands. We found about two dozen examples of products that had not been identified as novel foods according the current Regulation, yet could be considered to be classified as novel foods and hence for which a safety evaluation (toxicological and/or nutritional) would be indicated.

  7. Dispersive shock waves with nonlocal nonlinearity

    CERN Document Server

    Barsi, Christopher; Sun, Can; Fleischer, Jason W

    2007-01-01

    We consider dispersive optical shock waves in nonlocal nonlinear media. Experiments are performed using spatial beams in a thermal liquid cell, and results agree with a hydrodynamic theory of propagation.

  8. Dispersive shock waves with nonlocal nonlinearity.

    Science.gov (United States)

    Barsi, Christopher; Wan, Wenjie; Sun, Can; Fleischer, Jason W

    2007-10-15

    We consider dispersive optical shock waves in nonlocal nonlinear media. Experiments are performed using spatial beams in a thermal liquid cell, and results agree with a hydrodynamic theory of propagation.

  9. Analysis on Industry Structure Adjustment and Energy Consumption Based on Grey Theory——A Case Study of Qinghai Province

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In view of the complexity and non-linearity of energy consumption system and the status quo of the development of energy in Qinghai Province,the relations between energy consumption and industrial structure is analyzed by using the quantitative analysis of grey relation degree by using the grey system theory.The relevancy degree among the primary industry,the secondary industry and the tertiary industry and living energy consumption are obtained,and then the trend of energy consumption in the following several years can be predicted.The results show that the secondary industry has the largest relevancy degree to the total energy consumption.In the end,according to the results of the research,several suggestions on how to saving energy are put forward.Firstly,the government should improve the high-tech industry and restrict the development of high-consumption and high-pollution industries.Secondly,the government should promote the low-carbon way of life;promote energy saving and control the energy consumption of the department of life.Thirdly,clean production should be actively promoted in the tertiary industry and the circular economy should be vigorously expanded.

  10. Nonlinear channelizer

    Science.gov (United States)

    In, Visarath; Longhini, Patrick; Kho, Andy; Neff, Joseph D.; Leung, Daniel; Liu, Norman; Meadows, Brian K.; Gordon, Frank; Bulsara, Adi R.; Palacios, Antonio

    2012-12-01

    The nonlinear channelizer is an integrated circuit made up of large parallel arrays of analog nonlinear oscillators, which, collectively, serve as a broad-spectrum analyzer with the ability to receive complex signals containing multiple frequencies and instantaneously lock-on or respond to a received signal in a few oscillation cycles. The concept is based on the generation of internal oscillations in coupled nonlinear systems that do not normally oscillate in the absence of coupling. In particular, the system consists of unidirectionally coupled bistable nonlinear elements, where the frequency and other dynamical characteristics of the emergent oscillations depend on the system's internal parameters and the received signal. These properties and characteristics are being employed to develop a system capable of locking onto any arbitrary input radio frequency signal. The system is efficient by eliminating the need for high-speed, high-accuracy analog-to-digital converters, and compact by making use of nonlinear coupled systems to act as a channelizer (frequency binning and channeling), a low noise amplifier, and a frequency down-converter in a single step which, in turn, will reduce the size, weight, power, and cost of the entire communication system. This paper covers the theory, numerical simulations, and some engineering details that validate the concept at the frequency band of 1-4 GHz.

  11. Nonlinear plasmonics at high temperatures

    CERN Document Server

    Sivan, Yonatan

    2016-01-01

    We solve the Maxwell and heat equations self-consistently for metal nanoparticles under intense continuous wave (CW) illumination. Unlike previous studies, we rely on {\\em experimentally}-measured data for the metal permittivity for increasing temperature and for the visible spectral range. We show that the thermal nonlinearity of the metal can lead to substantial deviations from the predictions of the linear model for the temperature and field distribution, and thus, can explain qualitatively the strong nonlinear scattering from such configurations observed experimentally. We also show that the incompleteness of existing data of the temperature dependence of the thermal properties of the system prevents reaching a quantitative agreement between the measured and calculated scattering data. This modelling approach is essential for the identification of the underlying physical mechanism responsible for the thermo-optical nonlinearity of the metal and should be adopted in all applications of high temperature non...

  12. Fault Diagnosis in Transformer Based on Weighted Degree of Grey Slope Incidence of Optimized Entropy

    Directory of Open Access Journals (Sweden)

    Zhang Anping

    2016-01-01

    Full Text Available Dissolved gas analysis (DGA is an important method to find the hidden or incipient insulation faults of oil-immersed power transformer. However, code deficiency exists in the gas ratio methods specified by the IEC standard and complexity of fault diagnosis for power transformer. Hence a new model based on optimized weighted degree of grey slope incidence was put forward. Firstly, the entropy weight is used to determine objective weight of indices; then the model fault types are obtained by weighted degree of grey slope incidence. The combination of entropy weight with grey slope incidence analysis can fully utilize over all information of DGA and give full play to the superiority of grey slope incidence, which overcomes shortcomings of original grey slope incidence analysis. The experimental results also demonstrate that the improved method has higher accuracy compared with three-ratio method and general grey slope incidence analysis method. The diagnosis accuracy is 92.8%.

  13. Nonlinear interpolation fractal classifier for multiple cardiac arrhythmias recognition

    Energy Technology Data Exchange (ETDEWEB)

    Lin, C.-H. [Department of Electrical Engineering, Kao-Yuan University, No. 1821, Jhongshan Rd., Lujhu Township, Kaohsiung County 821, Taiwan (China); Institute of Biomedical Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China)], E-mail: eechl53@cc.kyu.edu.tw; Du, Y.-C.; Chen Tainsong [Institute of Biomedical Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China)

    2009-11-30

    This paper proposes a method for cardiac arrhythmias recognition using the nonlinear interpolation fractal classifier. A typical electrocardiogram (ECG) consists of P-wave, QRS-complexes, and T-wave. Iterated function system (IFS) uses the nonlinear interpolation in the map and uses similarity maps to construct various data sequences including the fractal patterns of supraventricular ectopic beat, bundle branch ectopic beat, and ventricular ectopic beat. Grey relational analysis (GRA) is proposed to recognize normal heartbeat and cardiac arrhythmias. The nonlinear interpolation terms produce family functions with fractal dimension (FD), the so-called nonlinear interpolation function (NIF), and make fractal patterns more distinguishing between normal and ill subjects. The proposed QRS classifier is tested using the Massachusetts Institute of Technology-Beth Israel Hospital (MIT-BIH) arrhythmia database. Compared with other methods, the proposed hybrid methods demonstrate greater efficiency and higher accuracy in recognizing ECG signals.

  14. Nonlinear dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Turchetti, G. (Bologna Univ. (Italy). Dipt. di Fisica)

    1989-01-01

    Research in nonlinear dynamics is rapidly expanding and its range of applications is extending beyond the traditional areas of science where it was first developed. Indeed while linear analysis and modelling, which has been very successful in mathematical physics and engineering, has become a mature science, many elementary phenomena of intrinsic nonlinear nature were recently experimentally detected and investigated, suggesting new theoretical work. Complex systems, as turbulent fluids, were known to be governed by intrinsically nonlinear laws since a long time ago, but received purely phenomenological descriptions. The pioneering works of Boltzmann and Poincare, probably because of their intrinsic difficulty, did not have a revolutionary impact at their time; it is only very recently that their message is reaching a significant number of mathematicians and physicists. Certainly the development of computers and computer graphics played an important role in developing geometric intuition of complex phenomena through simple numerical experiments, while a new mathematical framework to understand them was being developed.

  15. Method discussion for quick response grey prediction of stronger aftershocks of an earthquake sequence

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In this paper, we take occurrence process of early strong aftershocks of a main-after shock type′s earthquake sequence as a complex grey system, and introduce predicting method for its stronger aftershocks by grey predicting theory. Through inspection prediction for 1998 Zhangbei MS=6.2 earthquake sequence, it shows that the grey predicting method maybe has active significance for the investigation of quick response prediction problems of stronger aftershocks of an earthquake sequence.

  16. Based on Multi-Factors Grey Prediction Control for Elevator Velocity Modulation

    OpenAIRE

    2012-01-01

    This paper uses the double-factors grey prediction and the fuzzy controller for the elevator car speed control. We introduce double-factors grey control to predict car vibration for elevator speed during the operation. Simulation results show that based on multi-factors gray prediction fuzzy PI control for elevator velocity modulation system closer than simple gray fuzzy PI control elevator speed control system to the actual operation. The control effect of double factors grey fuzzy PI contro...

  17. Study of the Thermal Decomposition of PFPEs Lubricants on a Thin DLC Film Using Finitely Extensible Nonlinear Elastic Potential Based Molecular Dynamics Simulation

    Directory of Open Access Journals (Sweden)

    S. K. Deb Nath

    2014-01-01

    Full Text Available Perfluoropolyethers (PFPEs are widely used as hard disk lubricants for protecting carbon overcoat reducing friction between the hard disk interface and the head during the movement of head during reading and writing data in the hard disk. Due to temperature rise of PFPE Zdol lubricant molecules on a DLC surface, how polar end groups are detached from lubricant molecules during coating is described considering the effect of temperatures on the bond/break density of PFPE Zdol using the coarse-grained bead spring model based on finitely extensible nonlinear elastic potential. As PFPE Z contains no polar end groups, effects of temperature on the bond/break density (number of broken bonds/total number of bonds are not so significant like PFPE Zdol. Effects of temperature on the bond/break density of PFPE Z on DLC surface are also discussed with the help of graphical results. How bond/break phenomenonaffects the end bead density of PFPE Z and PFPE Zdol on DLC surface is discussed elaborately. How the overall bond length of PFPE Zdol increases with the increase of temperature which is responsible for its decomposition is discussed with the help of graphical results. At HAMR condition, as PFPE Z and PFPE Zdol are not suitable lubricant on a hard disk surface, it needs more investigations to obtain suitable lubricant. We study the effect of breaking of bonds of nonfunctional lubricant PFPE Z, functional lubricants such as PFPE Zdol and PFPE Ztetrao, and multidented functional lubricants such as ARJ-DS, ARJ-DD, and OHJ-DS on a DLC substrate with the increase of temperature when heating of all of the lubricants on a DLC substrate is carried out isothermally using the coarse-grained bead spring model by molecular dynamics simulations and suitable lubricant is selected which is suitable on a DLC substrate at high temperature.

  18. Synthesis, crystal growth, structural, spectral, thermal, mechanical, linear and nonlinear optical studies of organic single crystal 4-Iodo 4-nitrostilbene (IONS): A potential NLO material

    Energy Technology Data Exchange (ETDEWEB)

    Dinakaran, Paul M.; Kalainathan, S., E-mail: kalainathan@yahoo.com

    2013-12-16

    An organic nonlinear optical material 4-Iodo 4-nitrostilbene (IONS) has been synthesized and good optical quality single crystal was grown from ethyl methyl ketone solvent by the solution growth technique. Single and powder X-ray diffraction analyses reveals that the grown crystal belongs to monoclinic crystal system with noncentrosymmetric space group ‘P2{sub 1}’ and it has good crystalline nature. Functional groups and molecular structure of the title compound were confirmed by FTIR and {sup 1}H NMR respectively. The UV–Vis–NIR absorption study reveals no absorption in the visible region and the cut-off wavelength was found to be at 412.84 nm, TG/DTA, mass spectral analysis, photoluminescence and microhardness studies have been carried out for the grown crystals and results are discussed in detail. The second harmonic efficiency of the IONS was determined by Kurtz–Perry powder technique which reveals that the IONS crystal (3.1 V) has greater efficiency i.e., 143 times to that of KDP (21.7 mV). - Highlights: • The 4-Iodo 4-nitrostilbene (IONS) material has been synthesized by Wittig reaction. • The single crystal was grown for the first time with dimensions of 9.5 × 4 × 1.5 mm{sup 3}. • SHG efficiency of IONS is 143 times greater than that of KDP crystal. • The UV–Vis absorption study reveals that the transparency was found to be good. • IONS crystal is a potential candidate for optoelectronic applications.

  19. Premature hair greying may predict reduced bone mineral density in Graves' disease.

    LENUS (Irish Health Repository)

    Leary, A C

    2012-02-03

    BACKGROUND: Premature hair greying has been associated with low bone mineral density (BMD), and it may be more frequent in Graves\\' disease. AIMS: To determine whether premature greying is associated with reduced BMD in women with Graves\\' disease and in control women, and to examine whether premature greying is more common in Graves\\' disease. METHODS: Premature greying (> 50% grey by 40 years) and BMD were determined in 44 women with a history of Graves\\' disease and 133 female controls referred for routine BMD measurement. Exclusion criteria included diseases or drugs known to affect BMD. RESULTS: Mean Z and T scores at the lumbar spine were significantly lower (P < 0.04) in subjects with premature greying than in those not prematurely grey among women with Graves\\' disease, but not among control women. Multiple regression confirmed this difference between Graves\\' and control women (P = 0.041). There were no differences at other measurement sites. Of Graves\\' patients, 36% were prematurely grey compared with 25% of control women (P = 0.14). CONCLUSION: Premature greying may be a weak marker for reduced BMD in women with a history of Graves\\' disease, but it is not a marker in normal women.

  20. STUDIES ON GREY MODEL DYNAMIC PREDICTION TO CAVITATION DAMAGE OF TURBINES

    Institute of Scientific and Technical Information of China (English)

    Wu Fu-sheng; Tong Zhong-shan; Li Yun-hui

    2003-01-01

    In this paper, cavitation damage of turbines is firstly analyzed and predicated from the view point of system engineering by use of the grey system theory. A detailed description of modeling, dynamic prediction and accuracy test for the grey system of turbines was given. Two special cases for grey dynamic prediction as well as its accuracy test were illustrated. The results fall into the grade I, the accuracy is satisfactory and its prediction requirements can be met well. It shows that the grey system theory can be employed to predict the cavitation damage of turbines, and it can provide a scientific basis for timely investigation and maintenance of turbines.

  1. Grey extra-deleting theory-based governor control for hydro-generator unit

    Directory of Open Access Journals (Sweden)

    Ming-dong Wang

    2015-10-01

    Full Text Available The control effect by using the conventional method is not satisfied because of the grey character caused from time-variant parameters of hydro-generator units and its governor. The grey extra-deleting control theory is applied to the governor design of hydro-generator units in this paper. After the mathematic model of hydro-generator and its governor are founded, the grey extra-deleting controller is designed and its effect is studied compared with the conventional proportional–integral–derivative governor. The simulation results indicate that the grey extra-deleting controller can improve dynamic characteristic of hydro-generator units.

  2. Cellular and ultrastructural characterization of the grey-morph phenotype in southern right whales (Eubalaena australis).

    Science.gov (United States)

    Eroh, Guy D; Clayton, Fred C; Florell, Scott R; Cassidy, Pamela B; Chirife, Andrea; Marón, Carina F; Valenzuela, Luciano O; Campbell, Michael S; Seger, Jon; Rowntree, Victoria J; Leachman, Sancy A

    2017-01-01

    Southern right whales (SRWs, Eubalena australis) are polymorphic for an X-linked pigmentation pattern known as grey morphism. Most SRWs have completely black skin with white patches on their bellies and occasionally on their backs; these patches remain white as the whale ages. Grey morphs (previously referred to as partial albinos) appear mostly white at birth, with a splattering of rounded black marks; but as the whales age, the white skin gradually changes to a brownish grey color. The cellular and developmental bases of grey morphism are not understood. Here we describe cellular and ultrastructural features of grey-morph skin in relation to that of normal, wild-type skin. Melanocytes were identified histologically and counted, and melanosomes were measured using transmission electron microscopy. Grey-morph skin had fewer melanocytes when compared to wild-type skin, suggesting reduced melanocyte survival, migration, or proliferation in these whales. Grey-morph melanocytes had smaller melanosomes relative to wild-type skin, normal transport of melanosomes to surrounding keratinocytes, and normal localization of melanin granules above the keratinocyte nuclei. These findings indicate that SRW grey-morph pigmentation patterns are caused by reduced numbers of melanocytes in the skin, as well as by reduced amounts of melanin production and/or reduced sizes of mature melanosomes. Grey morphism is distinct from piebaldism and albinism found in other species, which are genetic pigmentation conditions resulting from the local absence of melanocytes, or the inability to synthesize melanin, respectively.

  3. Cellular and ultrastructural characterization of the grey-morph phenotype in southern right whales (Eubalaena australis)

    Science.gov (United States)

    Eroh, Guy D.; Clayton, Fred C.; Florell, Scott R.; Cassidy, Pamela B.; Chirife, Andrea; Marón, Carina F.; Valenzuela, Luciano O.; Campbell, Michael S.; Seger, Jon; Rowntree, Victoria J.; Leachman, Sancy A.

    2017-01-01

    Southern right whales (SRWs, Eubalena australis) are polymorphic for an X-linked pigmentation pattern known as grey morphism. Most SRWs have completely black skin with white patches on their bellies and occasionally on their backs; these patches remain white as the whale ages. Grey morphs (previously referred to as partial albinos) appear mostly white at birth, with a splattering of rounded black marks; but as the whales age, the white skin gradually changes to a brownish grey color. The cellular and developmental bases of grey morphism are not understood. Here we describe cellular and ultrastructural features of grey-morph skin in relation to that of normal, wild-type skin. Melanocytes were identified histologically and counted, and melanosomes were measured using transmission electron microscopy. Grey-morph skin had fewer melanocytes when compared to wild-type skin, suggesting reduced melanocyte survival, migration, or proliferation in these whales. Grey-morph melanocytes had smaller melanosomes relative to wild-type skin, normal transport of melanosomes to surrounding keratinocytes, and normal localization of melanin granules above the keratinocyte nuclei. These findings indicate that SRW grey-morph pigmentation patterns are caused by reduced numbers of melanocytes in the skin, as well as by reduced amounts of melanin production and/or reduced sizes of mature melanosomes. Grey morphism is distinct from piebaldism and albinism found in other species, which are genetic pigmentation conditions resulting from the local absence of melanocytes, or the inability to synthesize melanin, respectively. PMID:28170433

  4. Grey-Theory-Based Optimization Model of Emergency Logistics Considering Time Uncertainty.

    Directory of Open Access Journals (Sweden)

    Bao-Jian Qiu

    Full Text Available Natural disasters occur frequently in recent years, causing huge casualties and property losses. Nowadays, people pay more and more attention to the emergency logistics problems. This paper studies the emergency logistics problem with multi-center, multi-commodity, and single-affected-point. Considering that the path near the disaster point may be damaged, the information of the state of the paths is not complete, and the travel time is uncertainty, we establish the nonlinear programming model that objective function is the maximization of time-satisfaction degree. To overcome these drawbacks: the incomplete information and uncertain time, this paper firstly evaluates the multiple roads of transportation network based on grey theory and selects the reliable and optimal path. Then simplify the original model under the scenario that the vehicle only follows the optimal path from the emergency logistics center to the affected point, and use Lingo software to solve it. The numerical experiments are presented to show the feasibility and effectiveness of the proposed method.

  5. Grey-Theory-Based Optimization Model of Emergency Logistics Considering Time Uncertainty.

    Science.gov (United States)

    Qiu, Bao-Jian; Zhang, Jiang-Hua; Qi, Yuan-Tao; Liu, Yang

    2015-01-01

    Natural disasters occur frequently in recent years, causing huge casualties and property losses. Nowadays, people pay more and more attention to the emergency logistics problems. This paper studies the emergency logistics problem with multi-center, multi-commodity, and single-affected-point. Considering that the path near the disaster point may be damaged, the information of the state of the paths is not complete, and the travel time is uncertainty, we establish the nonlinear programming model that objective function is the maximization of time-satisfaction degree. To overcome these drawbacks: the incomplete information and uncertain time, this paper firstly evaluates the multiple roads of transportation network based on grey theory and selects the reliable and optimal path. Then simplify the original model under the scenario that the vehicle only follows the optimal path from the emergency logistics center to the affected point, and use Lingo software to solve it. The numerical experiments are presented to show the feasibility and effectiveness of the proposed method.

  6. Nonlinear acoustics in biomedical ultrasound

    Science.gov (United States)

    Cleveland, Robin O.

    2015-10-01

    Ultrasound is widely used to image inside the body; it is also used therapeutically to treat certain medical conditions. In both imaging and therapy applications the amplitudes employed in biomedical ultrasound are often high enough that nonlinear acoustic effects are present in the propagation: the effects have the potential to be advantageous in some scenarios but a hindrance in others. In the case of ultrasound imaging the nonlinearity produces higher harmonics that result in images of greater quality. However, nonlinear effects interfere with the imaging of ultrasound contrast agents (typically micron sized bubbles with a strong nonlinear response of their own) and nonlinear effects also result in complications when derating of pressure measurements in water to in situ values in tissue. High intensity focused ultrasound (HIFU) is emerging as a non-invasive therapeutic modality which can result in thermal ablation of tissue. For thermal ablation, the extra effective attenuation resulting from nonlinear effects can result in enhanced heating of tissue if shock formation occurs in the target region for ablation - a highly desirable effect. However, if nonlinearity is too strong it can also result in undesired near-field heating and reduced ablation in the target region. The disruption of tissue (histotripsy) and fragmentation of kidney stones (lithotripsy) exploits shock waves to produce mechanically based effects, with minimal heating present. In these scenarios it is necessary for the waves to be of sufficient amplitude that a shock exists when the waveform reaches the target region. This talk will discuss how underlying nonlinear phenomenon act in all the diagnostic and therapeutic applications described above.

  7. Comment on the paper "Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-chloro 4-nitrostilbene (CONS): a potential NLO material" by P.M. Dinakaran, S. Kalainathan [Spectrochim. Acta A 111 (2013) 123-130].

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R; Dhuri, Sunder N; Nadkarni, V S

    2014-01-03

    We argue that (trans)-4-chloro-4'-nitrostilbene is not a new organic nonlinear optical material as claimed by Dinakaran and Kalainathan [P.M. Dinakaran, S. Kalainathan, Synthesis, growth, structural, spectral, thermal, chemical etching, linear and nonlinear optical and mechanical studies of an organic single crystal 4-Chloro 4-Nitrostilbene (CONS): a potential NLO material, Spectrochim. Acta A 111 (2013) 123-130], but instead a well-known compound whose synthesis, spectral data, single crystal structure and second harmonic generation (SHG) efficiency are well documented in the literature. The title paper is completely erroneous. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Single-subject grey matter graphs in Alzheimer's disease.

    Science.gov (United States)

    Tijms, Betty M; Möller, Christiane; Vrenken, Hugo; Wink, Alle Meije; de Haan, Willem; van der Flier, Wiesje M; Stam, Cornelis J; Scheltens, Philip; Barkhof, Frederik

    2013-01-01

    Coordinated patterns of cortical morphology have been described as structural graphs and previous research has demonstrated that properties of such graphs are altered in Alzheimer's disease (AD). However, it remains unknown how these alterations are related to cognitive deficits in individuals, as such graphs are restricted to group-level analysis. In the present study we investigated this question in single-subject grey matter networks. This new method extracts large-scale structural graphs where nodes represent small cortical regions that are connected by edges when they show statistical similarity. Using this method, unweighted and undirected networks were extracted from T1 weighted structural magnetic resonance imaging scans of 38 AD patients (19 female, average age 72±4 years) and 38 controls (19 females, average age 72±4 years). Group comparisons of standard graph properties were performed after correcting for grey matter volumetric measurements and were correlated to scores of general cognitive functioning. AD networks were characterised by a more random topology as indicated by a decreased small world coefficient (p = 3.53×10(-5)), decreased normalized clustering coefficient (p = 7.25×10(-6)) and decreased normalized path length (p = 1.91×10(-7)). Reduced normalized path length explained significantly (p = 0.004) more variance in measurements of general cognitive decline (32%) in comparison to volumetric measurements (9%). Altered path length of the parahippocampal gyrus, hippocampus, fusiform gyrus and precuneus showed the strongest relationship with cognitive decline. The present results suggest that single-subject grey matter graphs provide a concise quantification of cortical structure that has clinical value, which might be of particular importance for disease prognosis. These findings contribute to a better understanding of structural alterations and cognitive dysfunction in AD.

  9. Increased microglial catalase activity in multiple sclerosis grey matter.

    Science.gov (United States)

    Gray, Elizabeth; Kemp, Kevin; Hares, Kelly; Redondo, Julianna; Rice, Claire; Scolding, Neil; Wilkins, Alastair

    2014-04-22

    Chronic demyelination, on-going inflammation, axonal loss and grey matter neuronal injury are likely pathological processes that contribute to disease progression in multiple sclerosis (MS). Although the precise contribution of each process and their aetiological substrates is not fully known, recent evidence has implicated oxidative damage as a major cause of tissue injury in MS. The degree of tissue injury caused by oxidative molecules, such as reactive oxygen species (ROS), is balanced by endogenous anti-oxidant enzymes which detoxify ROS. Understanding endogenous mechanisms which protect the brain against oxidative injury in MS is important, since enhancing anti-oxidant responses is a major therapeutic strategy for preventing irreversible tissue injury in the disease. Our aims were to determine expression and activity levels of the hydrogen peroxide-reducing enzyme catalase in MS grey matter (GM). In MS GM, a catalase enzyme activity was elevated compared to control GM. We measured catalase protein expression by immune dot-blotting and catalase mRNA by a real-time polymerase chain reaction (RT-PCR). Protein analysis studies showed a strong positive correlation between catalase and microglial marker IBA-1 in MS GM. In addition, calibration of catalase mRNA level with reference to the microglial-specific transcript AIF-1 revealed an increase in this transcript in MS. This was reflected by the extent of HLA-DR immunolabeling in MS GM which was significantly elevated compared to control GM. Collectively, these observations provide evidence that microglial catalase activity is elevated in MS grey matter and may be an important endogenous anti-oxidant defence mechanism in MS.

  10. Nonlinear Systems.

    Science.gov (United States)

    Seider, Warren D.; Ungar, Lyle H.

    1987-01-01

    Describes a course in nonlinear mathematics courses offered at the University of Pennsylvania which provides an opportunity for students to examine the complex solution spaces that chemical engineers encounter. Topics include modeling many chemical processes, especially those involving reaction and diffusion, auto catalytic reactions, phase…

  11. A Grey Decision Model Used in Bidding for Equipment Purchase

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Bidding has long been used as a method for allocating and procuring goods andservices.An acurrate and comprehensive evaluation of bidders is the key to make the bid-ding a successful one for tenderee. Howoever, evaluation of bidders is a tough work and theresult of evaluation is always affected by the evaluator's understanding of the standardsset for evaluation, and the evaluator's expertise, experience and preferrence. We make aneffort to find a method for selecting bidders as accurately as possible. A grey decisionmodel is presented, and an example is illustrated to make the practioners kenow how to usethe model.

  12. Parameter Estimation in Stochastic Grey-Box Models

    DEFF Research Database (Denmark)

    Kristensen, Niels Rode; Madsen, Henrik; Jørgensen, Sten Bay

    2004-01-01

    An efficient and flexible parameter estimation scheme for grey-box models in the sense of discretely, partially observed Ito stochastic differential equations with measurement noise is presented along with a corresponding software implementation. The estimation scheme is based on the extended...... Kalman filter and features maximum likelihood as well as maximum a posteriori estimation on multiple independent data sets, including irregularly sampled data sets and data sets with occasional outliers and missing observations. The software implementation is compared to an existing software tool...

  13. EUPHEMISTIC AND DYSPHEMISTIC LANGUAGE IN FIFTY SHADES OF GREY TRILOGY

    OpenAIRE

    Raquel Sánchez Ruiz

    2015-01-01

    El impacto de la trilogía Cincuenta sombras de Grey ha trascendido la popularidad de las masas y ha ocupado la atención de la academia. Esto se ha evidenciado en investigaciones que abordan la obra desde diferentes perspectivas. Sin embargo, aunque las novelas han sido estudiadas con cierta profundidad, no se ha prestado demasiada atención a su uso del lenguaje. Considerando que las historias eróticas son un campo donde el eufemismo y el disfemismo proliferan, este artículo analiza el uso de ...

  14. A Grey-Box Model for Spray Drying Plants

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Poulsen, Niels Kjølstad; Niemann, Hans Henrik

    2013-01-01

    Multi-stage spray drying is an important and widely used unit operation in the production of food powders. In this paper we develop and present a dynamic model of the complete drying process in a multi-stage spray dryer. The dryer is divided into three stages: The spray stage and two fluid bed...... are compared to datasets gathered at GEA Process Engineering’s test facility. The identified grey-box model parameters are identified from data and the resulting model fits the data well. The complexity of the model has been selected such that it is suitable for development of real-time optimization algorithms...

  15. Google AdWords as a Network of Grey Surveillance

    OpenAIRE

    Roberts, Harold M

    2010-01-01

    Google's AdWords processes information about what sorts of content users are browsing for about a quarter of all web site visits. The significance of AdWords' use of this vast amount of personal data lies not in its use for such obviously authoritarian purposes but instead as a network of grey surveillance with Google acting as the hub and the various publishers, advertisers, and users watching (and controlling) each other in distinct ways. Google's model of collective intelligence in its s...

  16. A terminological "journey" in the Grey Literature domain

    OpenAIRE

    Bartolini, Roberto; Pardelli, Gabriella; Goggi, Sara; Giannini, Silvia; Biagioni, Stefania

    2016-01-01

    ?When we read the articles or papers of a particular domain, we can recognize some lexical items in the texts as technical terms. In a domain where new knowledge is generated, new terms are constantly created to fulfil the needs of the domain, while others become obsolete. In addition, existing terms may undergo changes of meaning?? (Kageura K.,1998/1999). According to Kaugera, our aim with this work is to make a ?journey? in the Grey Literature (GL) domain in order to offer an overall vision...

  17. Grey interrelation analysis of alloy elements and steel corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jinglei; Hou Baorong; Huang Yanliang; Guo Gongyu [Chinese Academy of Sciences, Qingdao (China). Dept. of Oceanology

    2000-07-01

    Mathematical grey interrelation analysis method was used to study the correlation of alloy elements and low steel corrosion in the splash zone. Eighteen kinds of low alloy steels were selected for 350-day experiments in a large marine corrosion environment simulating apparatus. The analysis results showed that the correlation of alloy elements and alloy corrosion rate is in the order: Mn>Si>P>V>Cu>Al>Cr>Mo. The correlation degree was 0.92, 0.89, 0.86, 0.83, 0.82, 0.82, 0.81, 0.77. (orig.)

  18. A TEM Study on the Ti-Alloyed Grey Iron

    DEFF Research Database (Denmark)

    Moumeni, Elham; Tiedje, Niels Skat; Grumsen, Flemming Bjerg;

    2014-01-01

    The microstructure of graphite flakes in titanium alloyed cast iron is studied using electron microscopy techniques. Dual beam SEM/FIB has been used for TEM sample preparation. A TEM study has been carried out on graphite flakes in grey cast iron using selected area electron diffraction. Based...... on the selected area diffraction pattern analysis, crystallographic orientations are identified and compared. The orientation relationship between iron and graphite crystals at the interface is studied and discussed. It is found that graphite in the Ti-containing iron is extremely fine grained...

  19. Unsteady MHD Mixed Convection Slip Flow of Casson Fluid over Nonlinearly Stretching Sheet Embedded in a Porous Medium with Chemical Reaction, Thermal Radiation, Heat Generation/Absorption and Convective Boundary Conditions.

    Science.gov (United States)

    Ullah, Imran; Bhattacharyya, Krishnendu; Shafie, Sharidan; Khan, Ilyas

    2016-01-01

    Numerical results are presented for the effect of first order chemical reaction and thermal radiation on mixed convection flow of Casson fluid in the presence of magnetic field. The flow is generated due to unsteady nonlinearly stretching sheet placed inside a porous medium. Convective conditions on wall temperature and wall concentration are also employed in the investigation. The governing partial differential equations are converted to ordinary differential equations using suitable transformations and then solved numerically via Keller-box method. It is noticed that fluid velocity rises with increase in radiation parameter in the case of assisting flow and is opposite in the case of opposing fluid while radiation parameter has no effect on fluid velocity in the forced convection. It is also seen that fluid velocity and concentration enhances in the case of generative chemical reaction whereas both profiles reduces in the case of destructive chemical reaction. Further, increase in local unsteadiness parameter reduces fluid velocity, temperature and concentration. Over all the effects of physical parameters on fluid velocity, temperature and concentration distribution as well as on the wall shear stress, heat and mass transfer rates are discussed in detail.

  20. Growth, spectral, thermal, laser damage threshold, microhardness, dielectric, linear and nonlinear optical properties of an organic single crystal: L-phenylalanine DL-mandelic acid

    Energy Technology Data Exchange (ETDEWEB)

    Jayaprakash, P. [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604 407, Tamil Nadu (India); Peer Mohamed, M. [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604 407, Tamil Nadu (India); Department of Physics, C. Abdul Hakeem College, Melvisharam 632 509, Tamil Nadu (India); Krishnan, P. [Department of Physics, St. Joseph’s College of Engineering, Chennai 600 119, Tamil Nadu (India); Nageshwari, M.; Mani, G. [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604 407, Tamil Nadu (India); Lydia Caroline, M., E-mail: lydiacaroline2006@yahoo.co.in [PG & Research Department of Physics, Arignar Anna Govt. Arts College, Cheyyar 604 407, Tamil Nadu (India)

    2016-12-15

    Single crystals of L-phenylalanine dl-mandelic acid [C{sub 9}H{sub 11}NO{sub 2}. C{sub 8}H{sub 8}O{sub 3}], have been grown by the slow evaporation technique at room temperature using aqueous solution. The single crystal XRD study confirms monoclinic system for the grown crystal. The functional groups present in the grown crystal have been identified by FTIR and FT-Raman analyses. The optical absorption studies show that the crystal is transparent in the visible region with a lower cut-off wavelength of 257 nm and the optical band gap energy E{sub g} is determined to be 4.62 eV. The Kurtz powder second harmonic generation was confirmed using Nd:YAG laser with fundamental wavelength of 1064 nm. Further, the thermal studies confirmed no weight loss up to 150°C for the as-grown crystal. The photoluminescence spectrum exhibited three peaks (414 nm, 519 nm, 568 nm) due to the donation of protons from carboxylic acid to amino group. Laser damage threshold value was found to be 4.98 GW/cm{sup 2}. The Vickers microhardness test was carried out on the grown crystals and there by Vickers hardness number (H{sub v}), work hardening coefficient (n), yield strength (σ{sub y}), stiffness constant C{sub 11} were evaluated. The dielectric behavior of the crystal has been determined in the frequency range 50 Hz–5 MHz at various temperatures.

  1. Grey parrots use inferential reasoning based on acoustic cues alone.

    Science.gov (United States)

    Schloegl, Christian; Schmidt, Judith; Boeckle, Markus; Weiß, Brigitte M; Kotrschal, Kurt

    2012-10-22

    Our ability to make logical inferences is considered as one of the cornerstones of human intelligence, fuelling investigations of reasoning abilities in non-human animals. Yet, the evidence to date is equivocal, with apes as the prime candidates to possess these skills. For instance, in a two-choice task, apes can identify the location of hidden food if it is indicated by a rattling noise caused by the shaking of a baited container. More importantly, they also use the absence of noise during the shaking of the empty container to infer that this container is not baited. However, since the inaugural report of apes solving this task, to the best of our knowledge, no comparable evidence could be found in any other tested species such as monkeys and dogs. Here, we report the first successful and instantaneous solution of the shaking task through logical inference by a non-ape species, the African grey parrot. Surprisingly, the performance of the birds was sensitive to the shaking movement: they were successful with containers shaken horizontally, but not with vertical shaking resembling parrot head-bobbing. Thus, grey parrots seem to possess ape-like cross-modal reasoning skills, but their reliance on these abilities is influenced by low-level interferences.

  2. Cooperative problem solving in African grey parrots (Psittacus erithacus).

    Science.gov (United States)

    Péron, F; Rat-Fischer, L; Lalot, M; Nagle, L; Bovet, D

    2011-07-01

    One of the main characteristics of human societies is the extensive degree of cooperation among individuals. Cooperation is an elaborate phenomenon, also found in non-human primates during laboratory studies and field observations of animal hunting behaviour, among other things. Some authors suggest that the pressures assumed to have favoured the emergence of social intelligence in primates are similar to those that may have permitted the emergence of complex cognitive abilities in some bird species such as corvids and psittacids. In the wild, parrots show cooperative behaviours such as bi-parental care and mobbing. In this study, we tested cooperative problem solving in African grey parrots (Psittacus erithacus). Our birds were tested using several experimental setups to explore the different levels of behavioural organisation between participants, differing in temporal and spatial complexity. In our experiments, African grey parrots were able to act simultaneously but mostly failed during the delay task, maybe because of a lack of inhibitory motor response. Confronted with the possibility to adapt their behaviour to the presence or absence of a partner, they showed that they were able to coordinate their actions. They also collaborated, acting complementarily in order to solve tasks, but they were not able to place themselves in the partner's role.

  3. Modified Discrete Grey Wolf Optimizer Algorithm for Multilevel Image Thresholding

    Directory of Open Access Journals (Sweden)

    Linguo Li

    2017-01-01

    Full Text Available The computation of image segmentation has become more complicated with the increasing number of thresholds, and the option and application of the thresholds in image thresholding fields have become an NP problem at the same time. The paper puts forward the modified discrete grey wolf optimizer algorithm (MDGWO, which improves on the optimal solution updating mechanism of the search agent by the weights. Taking Kapur’s entropy as the optimized function and based on the discreteness of threshold in image segmentation, the paper firstly discretizes the grey wolf optimizer (GWO and then proposes a new attack strategy by using the weight coefficient to replace the search formula for optimal solution used in the original algorithm. The experimental results show that MDGWO can search out the optimal thresholds efficiently and precisely, which are very close to the result examined by exhaustive searches. In comparison with the electromagnetism optimization (EMO, the differential evolution (DE, the Artifical Bee Colony (ABC, and the classical GWO, it is concluded that MDGWO has advantages over the latter four in terms of image segmentation quality and objective function values and their stability.

  4. Reproductive cycle of grey mullet Mugil cephalus L.

    Directory of Open Access Journals (Sweden)

    Ana Luísa Rente Medeiros

    2014-06-01

    Full Text Available Grey mullet it is an ecological and biologically important species suitable for sustainable aquaculture. It plays an important role for the economy of several Mediterranean countries, where it is produced in aquaculture based on capture of wild juveniles. The capture of wild juveniles for aquaculture it is not sustainable, and therefore the reproductive cycle must be known in order to obtain eggs for larval production. In this species, the reproductive cycle is still not closed for aquaculture purposes. This work presents the results obtained on a study on the reproductive cycle of grey mullet Mugil cephalus L. based on oocyte diameter measured over a period of one year at Olhão Aquaculture Research Center (EPPO. Monthly measures of body weight, standard and fork length of 15 females kept in 18 m3 tanks in natural conditions were recorded. The state of ovarian maturity was evaluated based on the oocyte diameter. The mean length of the females were 56,41 cm ± 26,71 and the weight 1770,91 g ± 5,70 and the results obtained so far suggests that spawning must occur during Summer.

  5. A Grey Fuzzy Logic Approach for Cotton Fibre Selection

    Science.gov (United States)

    Chakraborty, Shankar; Das, Partha Protim; Kumar, Vidyapati

    2017-06-01

    It is a well known fact that the quality of ring spun yarn predominantly depends on various physical properties of cotton fibre. Any variation in these fibre properties may affect the strength and unevenness of the final yarn. Thus, so as to achieve the desired yarn quality and characteristics, it becomes imperative for the spinning industry personnel to identify the most suitable cotton fibre from a set of feasible alternatives in presence of several conflicting properties/attributes. This cotton fibre selection process can be modelled as a Multi-Criteria Decision Making (MCDM) problem. In this paper, a grey fuzzy logic-based approach is proposed for selection of the most apposite cotton fibre from 17 alternatives evaluated based on six important fibre properties. It is observed that the preference order of the top-ranked cotton fibres derived using the grey fuzzy logic approach closely matches with that attained by the past researchers which proves the application potentiality of this method in solving varying MCDM problems in textile industries.

  6. Modified Grey Wolf Optimizer for Global Engineering Optimization

    Directory of Open Access Journals (Sweden)

    Nitin Mittal

    2016-01-01

    Full Text Available Nature-inspired algorithms are becoming popular among researchers due to their simplicity and flexibility. The nature-inspired metaheuristic algorithms are analysed in terms of their key features like their diversity and adaptation, exploration and exploitation, and attractions and diffusion mechanisms. The success and challenges concerning these algorithms are based on their parameter tuning and parameter control. A comparatively new algorithm motivated by the social hierarchy and hunting behavior of grey wolves is Grey Wolf Optimizer (GWO, which is a very successful algorithm for solving real mechanical and optical engineering problems. In the original GWO, half of the iterations are devoted to exploration and the other half are dedicated to exploitation, overlooking the impact of right balance between these two to guarantee an accurate approximation of global optimum. To overcome this shortcoming, a modified GWO (mGWO is proposed, which focuses on proper balance between exploration and exploitation that leads to an optimal performance of the algorithm. Simulations based on benchmark problems and WSN clustering problem demonstrate the effectiveness, efficiency, and stability of mGWO compared with the basic GWO and some well-known algorithms.

  7. Quantum well nonlinear microcavities

    Science.gov (United States)

    Oudar, J. L.; Kuszelewicz, R.; Sfez, B.; Pellat, D.; Azoulay, R.

    We report on recent progress in reducing the power threshold of all-optical bistable quantum well vertical microcavities. Significant improvements are achieved through an increase of the cavity finesse, together with a reduction of the device active layer thickness. A critical intensity of 5 μW/μm 2 has been observed on a microcavity of finesse 250, with a nonlinear medium of only 18 GaAs quantum wells of 10 nm thickness. Further improvements of the Bragg mirror quality resulted in a finesse of 700 and a power-lifetime product of 15 fJ/μm 2. Microresonator pixellation allows to obtain 2-dimensional arrays. A thermally-induced alloy-mixing technique is described, which produced a 110 meV carrier confinement energy, together with a refractive index change of -.012, averaged over the 2.6 μm nonlinear medium thickness. The resulting electrical and optical confinement is shown to improve the nonlinear characteristics, by limiting lateral carrier diffusion and light diffraction.

  8. Nonlinear PDEs

    OpenAIRE

    2015-01-01

    From the Back Cover: The emphasis throughout the present volume is on the practical application of theoretical mathematical models helping to unravel the underlying mechanisms involved in processes from mathematical physics and biosciences. It has been conceived as a unique collection of abstract methods dealing especially with nonlinear partial differential equations (either stationary or evolutionary) that are applied to understand concrete processes involving some important applications re...

  9. Application of Grey Relational Cluster Method in Muon Tomography for Materials Detection

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    When the number of particles is small, We try to use grey system theory better in dealing the work which has little sample and incomplete information. Grey relational cluster method is applied for materials detection of the research of Muon tomography

  10. Pricing rainbow, green, blue and grey water: tree cover and geopolitics of climatic teleconnections

    NARCIS (Netherlands)

    Noordwijk, van M.; Namirembe, S.; Catacutan, D.; Williamson, D.; Gebrekirstos, A.

    2014-01-01

    Atmospheric moisture (“rainbow water”) is the source of all green, blue and grey water flows. Current water-related legislation and policies have moved beyond blue (water allocation) and grey (waste water treatment) water concerns to incorporate the green water concept of additional water use by fas

  11. Dependence of quality properties for grey iron on used raw materials

    Directory of Open Access Journals (Sweden)

    E. Weiss

    2009-01-01

    Full Text Available Grey iron castings keep the first place among castings on base of iron. Present trend in growing entrance production costs of cast stock force manufacturer to cost minimizing. Therefore is most actual deal replacement pig iron by steel scrap. In contribution are presented results research work relating to influence of raw materials on grey iron properties.

  12. The Automatic indexing of Grey Literature by Subject Headings of the Polythematic Structured Subject Heading System

    OpenAIRE

    Kocourek, Pavel

    2013-01-01

    The contribution is devoted to the automatic indexing of grey literature by subject headings of the Polythematic Structured Subject Heading System in the National repository of grey literature. The paper describes the initial situation, previous experience, analysis, stages of implementation and demonstration of indexing.

  13. Vocal Learning in Grey Parrots: A Brief Review of Perception, Production, and Cross-Species Comparisons

    Science.gov (United States)

    Pepperberg, Irene M.

    2010-01-01

    This chapter briefly reviews what is known-and what remains to be understood--about Grey parrot vocal learning. I review Greys' physical capacities--issues of auditory perception and production--then discuss how these capacities are used in vocal learning and can be recruited for referential communication with humans. I discuss cross-species…

  14. Forecasting Performance of Grey Prediction for Education Expenditure and School Enrollment

    Science.gov (United States)

    Tang, Hui-Wen Vivian; Yin, Mu-Shang

    2012-01-01

    GM(1,1) and GM(1,1) rolling models derived from grey system theory were estimated using time-series data from projection studies by National Center for Education Statistics (NCES). An out-of-sample forecasting competition between the two grey prediction models and exponential smoothing used by NCES was conducted for education expenditure and…

  15. Modelling the Heat Consumption in District Heating Systems using a Grey-box approach

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Madsen, Henrik

    2006-01-01

    identification of an overall model structure followed by data-based modelling, whereby the details of the model are identified. This approach is sometimes called grey-box modelling, but the specific approach used here does not require states to be specified. Overall, the paper demonstrates the power of the grey......-box approach. (c) 2005 Elsevier B.V. All rights reserved....

  16. Pricing rainbow, green, blue and grey water: tree cover and geopolitics of climatic teleconnections

    NARCIS (Netherlands)

    Noordwijk, van M.; Namirembe, S.; Catacutan, D.; Williamson, D.; Gebrekirstos, A.

    2014-01-01

    Atmospheric moisture (“rainbow water”) is the source of all green, blue and grey water flows. Current water-related legislation and policies have moved beyond blue (water allocation) and grey (waste water treatment) water concerns to incorporate the green water concept of additional water use by fas

  17. Forecasting Performance of Grey Prediction for Education Expenditure and School Enrollment

    Science.gov (United States)

    Tang, Hui-Wen Vivian; Yin, Mu-Shang

    2012-01-01

    GM(1,1) and GM(1,1) rolling models derived from grey system theory were estimated using time-series data from projection studies by National Center for Education Statistics (NCES). An out-of-sample forecasting competition between the two grey prediction models and exponential smoothing used by NCES was conducted for education expenditure and…

  18. Improved Energy Recovery by Anaerobic Grey Water Sludge Treatment with Black Water

    NARCIS (Netherlands)

    Tervahauta, T.H.; Bryant, I.M.; Hernandez Leal, L.; Buisman, C.J.N.; Zeeman, G.

    2014-01-01

    This study presents the potential of combining anaerobic grey water sludge treatment with black water in an up-flow anaerobic sludge blanket (UASB) reactor to improve energy recovery within source-separated sanitation concepts. Black water and the mixture of black water and grey water sludge were co

  19. Removal of micropollutants from grey water : combining biological and physical/chemical processes

    NARCIS (Netherlands)

    Hernandez Leal, L.

    2010-01-01

    Grey water consists of the discharges from kitchen sinks, showers, baths, washing machines and hand basins. The amount of grey water produced per person in The Netherlands is about 90 Ld-1, accounting for up to 75 % of the wastewater volume produced by households, and over 90 % if vacuum toilets are

  20. Modelling the Heat Consumption in District Heating Systems using a Grey-box approach

    DEFF Research Database (Denmark)

    Nielsen, Henrik Aalborg; Madsen, Henrik

    2006-01-01

    identification of an overall model structure followed by data-based modelling, whereby the details of the model are identified. This approach is sometimes called grey-box modelling, but the specific approach used here does not require states to be specified. Overall, the paper demonstrates the power of the grey......-box approach. (c) 2005 Elsevier B.V. All rights reserved....

  1. Grey game theory and its applications in economic decision-making

    CERN Document Server

    Fang, Zhigeng; Shi, Hongxing; Lin, Yi

    2016-01-01

    To make the best decisions, you need the best information. However, because most issues in game theory are grey, nearly all recent research has been carried out using a simplified method that considers grey systems as white ones. This often results in a forecasting function that is far from satisfactory when applied to many real situations. Grey Game Theory and Its Applications in Economic Decision Making introduces classic game theory into the realm of grey system theory with limited knowledge. The book resolves three theoretical issues: A game equilibrium of grey game A reasonable explanation for the equilibrium of a grey matrix of static nonmatrix game issues based on incomplete information The Centipede Game paradox, which has puzzled theory circles for a long time and greatly enriched and developed the core methods of subgame Nash perfect equilibrium analysis as a result   The book establishes a grey matrix game model based on pure and mixed strategies. The author proposes the concepts of grey saddle p...

  2. Removal of micropollutants from grey water : combining biological and physical/chemical processes

    NARCIS (Netherlands)

    Hernandez Leal, L.

    2010-01-01

    Grey water consists of the discharges from kitchen sinks, showers, baths, washing machines and hand basins. The amount of grey water produced per person in The Netherlands is about 90 Ld-1, accounting for up to 75 % of the wastewater volume produced by households, and over 90 % if vacuum toilets are

  3. Synthesis of Imidazole Derivatives for Their Second-order Nonlinear Optics

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The design and the synthesis of two conjugated donor-acceptor imidazole derivatives(1, 2) were carried out for second-order nonlinear optics. The thermal properties, the transparency and second-order nonlinear optical properties of the molecules were investigated. The experimental results indicate that a good nonlinearity-transparency-thermal stability trade-off is achieved for them.

  4. Improved Energy Recovery by Anaerobic Grey Water Sludge Treatment with Black Water

    Directory of Open Access Journals (Sweden)

    Taina Tervahauta

    2014-08-01

    Full Text Available This study presents the potential of combining anaerobic grey water sludge treatment with black water in an up-flow anaerobic sludge blanket (UASB reactor to improve energy recovery within source-separated sanitation concepts. Black water and the mixture of black water and grey water sludge were compared in terms of biochemical methane potential (BMP, UASB reactor performance, chemical oxygen demand (COD mass balance and methanization. Grey water sludge treatment with black water increased the energy recovery by 23% in the UASB reactor compared to black water treatment. The increase in the energy recovery can cover the increased heat demand of the UASB reactor and the electricity demand of the grey water bioflocculation system with a surplus of 0.7 kWh/cap/y electricity and 14 MJ/cap/y heat. However, grey water sludge introduced more heavy metals in the excess sludge of the UASB reactor and might therefore hinder its soil application.

  5. Grey Prediction Fuzzy Control of the Target Tracking System in a Robot Weapon

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-zhong; JI Jiang-tao; WANG Hong-ru

    2007-01-01

    Grey modeling can be used to predict the behavioral development of a system and find out the lead control values of the system. By using fuzzy inference, PID parameters can be adjusted on line by the fuzzy controller with PID parameters self-tuning. According to the characteristics of target tracking system in a robot weapon, grey prediction theory and fuzzy PID control ideas are combined. A grey prediction mathematical model is constructed and a fuzzy PID controller with grey prediction was developed. Simulation result shows fuzzy PID control algorithm with grey prediction is an efficient method that can improve the control equality and robustness of traditional PID control and fuzzy PID control, and has much better performance for target tracking.

  6. A Whiter Shade of Grey: A new approach to archaeological grey literature using the XML version of the TEI Guidelines

    Directory of Open Access Journals (Sweden)

    Gail Falkingham

    2005-04-01

    Full Text Available This article has arisen through the author's interest in two contemporary issues within archaeology: the production and dissemination of grey literature and the potential of XML. Grey literature is examined, with specific reference to unpublished reports literature produced in the present climate of developer-funded archaeology in England. There are concerns about the accessibility of this literature, both from within and beyond the archaeological profession. The vast majority of reports are word-processed and then printed in hard-copy format for limited distribution. The original, digital document however, has largely been seen as a by-product. Awareness of the importance of these digital reports, and their preservation must be raised. Electronic means of delivery and dissemination via the World Wide Web offer huge potential and present opportunities for new ways of working. Archaeology is not alone in seeking to promote the accessibility of grey literature; indeed there are many disciplines that have created online initiatives aiming to do just this, utilising a variety of means and a range of electronic file formats. The use of XML technology appears to offer many advantages over traditional formats, such as word-processed, PDF and even (XHTML files, particularly with regard to the manipulation and presentation of encoded electronic text. Increasingly, XML technology is being used for electronic delivery and dissemination and the pros and cons of so doing are discussed in this article. This theme has been developed by the author through a 'proof of concept' practical case study of three unpublished grey literature archaeology reports from the North Yorkshire Historic Environment Record. XML documents have been created from the original word-processed electronic reports by the manual application of XML markup, the methodology for which was devised following the XML version of the Text Encoding Initiative's TEI P4 Guidelines. The level of

  7. High-purity control of internal thermally coupled distillation columns based on nonlinear Wave model%基于非线性Wave模型的内部热耦合塔高纯控制方案

    Institute of Scientific and Technical Information of China (English)

    丛琳; 刘兴高; 周叶翔

    2012-01-01

    为了解决高纯内部热耦合精馏塔( ITCDIC)的强非线性特性给控制器的设计带来较大困难的问题,将非线性Wave理论运用到内部热耦合精馏塔的控制设计中.首先根据浓度曲线的特性提出了浓度波形的描述函数.其次根据波形描述函数以及物料守恒关系推导出波速公式.最后将Wave理论与一般模型控制(GMC)结合起来,建立了基于Wave模型的一般模型控制(WGMC).在苯-甲苯物系的实例研究中与传统的基于数据模型的一般模型控制(TGMC)进行比较.研究结果表明,WGMC在伺服控制和干扰控制的表现都明显优于TGMC,WGMC控制方案较传统的一般模型控制方案更加稳定可靠.%To solve the problem that high-purity internal thermally coupled distillation columns (ITCDIC) present strong nonlinear dynamics which troubles the controller design, nonlinear wave theory is introduced into the control design of ITCDIC. First, the describing function of the profile of concentration is proposed according to the characteristics of the concentration curve. Then, the wave velocity is derived from describing function of the concentration profile and component mass balance of each stage. Finally, combining the Wave model with the generic model control (GMC) a generic model control based on the Wave model (WGMC) is proposed. Compared with data-based generic model control (TGMC) in benzene-toluene system, WGMC performs more excellently both in servo control and regulatory control and it is more stable and efficient than the generic model control scheme.

  8. Grey nurse shark (Carcharias taurus) diving tourism: Tourist compliance and shark behaviour at Fish Rock, Australia.

    Science.gov (United States)

    Smith, Kirby; Scarr, Mark; Scarpaci, Carol

    2010-11-01

    Humans can dive with critically endangered grey nurse sharks (Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.

  9. Grey Nurse Shark ( Carcharias taurus) Diving Tourism: Tourist Compliance and Shark Behaviour at Fish Rock, Australia

    Science.gov (United States)

    Smith, Kirby; Scarr, Mark; Scarpaci, Carol

    2010-11-01

    Humans can dive with critically endangered grey nurse sharks ( Carcharias taurus) along the east coast of Australia. This study investigated both compliance of tourist divers to a code of conduct and legislation and the behaviour of grey nurse sharks in the presence of divers. A total of 25 data collection dives were conducted from December 2008 to January 2009. Grey nurse shark and diver behaviour were documented using 2-min scan samples and continuous observation. The proportion of time spent observing human-shark interactions was 9.4% of total field time and mean human-shark interaction time was 15.0 min. Results were used to gauge the effectiveness of current management practices for the grey nurse shark dive industry at Fish Rock in New South Wales, Australia. Grey nurse shark dive tourists were compliant to stipulations in the code of conduct and legislation (compliance ranged from 88 to 100%). The research detailed factors that may promote compliance in wildlife tourism operations such as the clarity of the stipulations, locality of the target species and diver perceptions of sharks. Results indicated that grey nurse sharks spent the majority of their time milling (85%) followed by active swimming (15%). Milling behaviour significantly decreased in the presence of more than six divers. Distance between sharks and divers, interaction time and number of sharks were not significantly correlated with grey nurse shark school behaviour. Jaw gaping, rapid withdrawal and stiff or jerky movement were the specific behaviours of grey nurse sharks that occurred most frequently and were associated with distance between divers and sharks and the presence of six or more divers. Revision of the number of divers allowed per interaction with a school of grey nurse sharks and further research on the potential impacts that shark-diving tourism may pose to grey nurse sharks is recommended.

  10. New developments in high quality grey cast irons

    Institute of Scientific and Technical Information of China (English)

    Iulian Riposan; Mihai Chisamera; Stelian Stan

    2014-01-01

    The paper reviews original data obtained by the present authors, revealed in recent separate publications, describing speciifc procedures for high quality grey irons, and relfecting the forecast needs of the worldwide iron foundry industry. High power, medium frequency coreless induction furnaces are commonly used in electric melting grey iron foundries. This has resulted in low sulphur (1,500 °C), contributing to unfavourable conditions for graphite nucleation. Thin wall castings are increasingly produced by these electric melt shops with a risk of greater eutectic undercooling during solidiifcation. The paper focused on two groups of grey cast irons and their speciifc problems: carbides and graphite morphology control in lower carbon equivalent high strength irons (CE=3.4%-3.8%), and austenite dendrite promotion in eutectic and slightly hypereutectic irons (CE=4.1%-4.5%), in order to increase their strength characteristics. There are 3 stages and 3 steps involving graphite formation, iron chemistry and iron processing that appear to be important. The concept in the present paper sustains a three-stage model for nucleating flake graphite [(Mn,X)S type nuclei]. There are three important groups of elements (deoxidizer,Mn/S, and inoculant) and three technological stages in electric melting of iron (superheat, pre-conditioning of base iron, ifnal inoculation). Attention is drawn to a control factor (%Mn) x (%S) ensuring it equals to 0.03- 0.06, accompanied by 0.005wt.%-0.010wt.% Al and/or Zr content in inoculated irons. It was found that iron powder addition promotes austenite dendrite formation in eutectic and slightly eutectic, acting as reinforcement for the eutectic cells. But, there is an accompanying possible negative influence on the characteristics of the (Mn,X)S type graphite nuclei (change the morphology of nuclei from polygonal compact to irregular polygonal, and therefore promote chill tendency in treated irons). A double addition (iron powder + inoculant

  11. New developments in high quality grey cast irons

    Directory of Open Access Journals (Sweden)

    Iulian Riposan

    2014-07-01

    Full Text Available The paper reviews original data obtained by the present authors, revealed in recent separate publications, describing specific procedures for high quality grey irons, and reflecting the forecast needs of the worldwide iron foundry industry. High power, medium frequency coreless induction furnaces are commonly used in electric melting grey iron foundries. This has resulted in low sulphur (1,500 °C, contributing to unfavourable conditions for graphite nucleation. Thin wall castings are increasingly produced by these electric melt shops with a risk of greater eutectic undercooling during solidification. The paper focused on two groups of grey cast irons and their specific problems: carbides and graphite morphology control in lower carbon equivalent high strength irons (CE=3.4%-3.8%, and austenite dendrite promotion in eutectic and slightly hypereutectic irons (CE=4.1%-4.5%, in order to increase their strength characteristics. There are 3 stages and 3 steps involving graphite formation, iron chemistry and iron processing that appear to be important. The concept in the present paper sustains a threestage model for nucleating flake graphite [(Mn,XS type nuclei]. There are three important groups of elements (deoxidizer, Mn/S, and inoculant and three technological stages in electric melting of iron (superheat, pre-conditioning of base iron, final inoculation. Attention is drawn to a control factor (%Mn x (%S ensuring it equals to 0.03 – 0.06, accompanied by 0.005wt.%–0.010wt.% Al and/or Zr content in inoculated irons. It was found that iron powder addition promotes austenite dendrite formation in eutectic and slightly eutectic, acting as reinforcement for the eutectic cells. But, there is an accompanying possible negative influence on the characteristics of the (Mn,XS type graphite nuclei (change the morphology of nuclei from polygonal compact to irregular polygonal, and therefore promote chill tendency in treated irons. A double addition (iron

  12. Grey matter, an endophenotype for schizophrenia? A voxel-based morphometry study in siblings of patients with schizophrenia

    NARCIS (Netherlands)

    van der Velde, Jorien; Gromann, Paula M.; Swart, Marte; de Haan, Lieuwe; Wiersma, Durk; Bruggeman, Richard; Krabbendam, Lydia; Aleman, Andre

    2015-01-01

    Background Grey matter, both volume and concentration, has been proposed as an endophenotype for schizophrenia given a number of reports of grey matter abnormalities in relatives of patients with schizophrenia. However, previous studies on grey matter abnormalities in relatives have produced inconsi

  13. Chitosan based grey wastewater treatment--a statistical design approach.

    Science.gov (United States)

    Thirugnanasambandham, K; Sivakumar, V; Prakash Maran, J; Kandasamy, S

    2014-01-01

    In this present study, grey wastewater was treated under different operating conditions such as agitation time (1-3 min), pH (2.5-5.5), chitosan dose (0.3-0.6g/l) and settling time (10-20 min) using response surface methodology (RSM). Four factors with three levels Box-Behnken response surface design (BBD) were employed to optimize and investigate the effect of process variables on the responses such as turbidity, BOD and COD removal. The results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial models were developed in order to predict the responses. Under the optimum conditions, experimental values such as turbidity (96%), BOD (91%) and COD (73%) removals are closely agreed with predicted values.

  14. An EPQ model with imperfect items using interval grey numbers

    Directory of Open Access Journals (Sweden)

    Erdal Aydemir

    2015-01-01

    Full Text Available The classic economic production quantity (EPQ model has been widely used to determine the optimal production quantity. However, the analysis for finding an EPQ model has many weaknesses which lead many researchers and practitioners to make extensions in several aspects on the original EPQ model. The basic assumption of EPQ model is that 100% of manufactured products are non-defective that is not valid for many production processes generally. The purpose of this paper is to develop an EPQ model with grey demand rate and cost values with maximum backorder level allowed with the good quality items in units under an imperfect production process. The imperfect items are considered to be low quality items which are sold to a particular purchaser at a lower price and, the others are reworked and scrapped. A mathematical model is developed and then an industrial example is presented on the wooden chipboard production process for illustration of the proposed model.

  15. Emergence of Linguistic Communication: Studies on Grey Parrots

    Science.gov (United States)

    Pepperberg, Irene M.

    Most studies on the evolution of communication systems concentrate on the primate lineage, ignoring the concept of parallel lines of evolution. Although phylogenetically remote from humans, some birds—particularly Grey parrots—share many cognitive and communicative abilities with humans. On certain tasks, they demonstrate processing abilities comparable to 5-6 year-old humans; they learn very simple vocal syntactic patterns and referential elements of human communication, but only through social interaction and in a manner that proceeds in ways similar to those of humans. Given this knowledge of vocal learning in birds, of the effects of social interaction on such learning, and of birds' complex cognitive abilities, we should not ignore the avian line if we wish to determine the evolutionary pressures that purportedly affected the evolution of complex communication systems—particularly vocal systems—and develop theories and models that can be tested.

  16. Lorenz Wind Disturbance Model Based on Grey Generated Components

    Directory of Open Access Journals (Sweden)

    Yagang Zhang

    2014-11-01

    Full Text Available In order to meet the needs of wind speed prediction in wind farms, we consider the influence of random atmospheric disturbances on wind variations. Considering a simplified fluid convection mode, a Lorenz system can be employed as an atmospheric disturbance model. Here Lorenz disturbance is defined as the European norm of the solutions of the Lorenz equation. Grey generating and accumulated generating models are employed to explore the relationship between wind speed and its related disturbance series. We conclude that a linear or quadric polynomial generating model are optimal through the verification of short-term wind speed prediction in the Sotavento wind farm. The new proposed model not only greatly improves the precision of short-term wind speed prediction, but also has great significance for the maintenance and stability of wind power system operation.

  17. Selecting an optimal mixed products using grey relationship model

    Directory of Open Access Journals (Sweden)

    Farshad Faezy Razi

    2013-06-01

    Full Text Available This paper presents an integrated supplier selection and inventory management using grey relationship model (GRM as well as multi-objective decision making process. The proposed model of this paper first ranks different suppliers based on GRM technique and then determines the optimum level of inventory by considering different objectives. To show the implementation of the proposed model, we use some benchmark data presented by Talluri and Baker [Talluri, S., & Baker, R. C. (2002. A multi-phase mathematical programming approach for effective supply chain design. European Journal of Operational Research, 141(3, 544-558.]. The preliminary results indicate that the proposed model of this paper is capable of handling different criteria for supplier selection.

  18. Causality in condensates: grey solitons as remnants of BEC formation

    Energy Technology Data Exchange (ETDEWEB)

    Zurek, Wojciech H [Los Alamos National Laboratory

    2008-01-01

    Symmetry breaking during phase transitions can lead to the formation of topological defects (such as vortex lines in superfluids). However, the usually studied BEC's have the shape of a cigar, a geometry that impedes vortex formation, survival, and detection. I show that, in elongated traps, one can expect the formation of 'grey solitons' (long-lived, non-topological 'phase defects') as a result of the same mechanism. Their number will rise approximately in proportion to the transition rate. This steep rise is due to the increasing size of the region of the BEC cigar where the phase of the condensate wavefunction is chosen locally (rather than passed on from the already formed BEC).

  19. EUPHEMISTIC AND DYSPHEMISTIC LANGUAGE IN FIFTY SHADES OF GREY TRILOGY

    Directory of Open Access Journals (Sweden)

    Raquel Sánchez Ruiz

    2015-01-01

    Full Text Available The popularity of Fifty Shades of Grey trilogy is beyond doubt. This great impact has also been reflected on academic literature dealing with the novel from different perspectives. However, while there is substantial research on the novels, little attention has been paid to the author's usage of language. Bearing in mind that erotic stories are a common euphemistic and dysphemistic ground, the aim of this paper is to explore euphemism, dysphemism and x-phemism (quasieuphemism and quasidysphemism in a corpus which consists of the three books of the mentioned trilogy so as to observe if the use of these devices depends on sexes and how these phenomena merge with metaphorical or metonymical devices to avoid a possible loss of face or highlight a taboo. The conclusions will show that the male and female main characters in the novels use language differently and employ these verbal devices with several intentions.

  20. Nonrelativistic grey Sn-transport radiative-shock solutions

    Science.gov (United States)

    Ferguson, J. M.; Morel, J. E.; Lowrie, R. B.

    2017-06-01

    We present semi-analytic radiative-shock solutions in which grey Sn-transport is used to model the radiation, and we include both constant cross sections and cross sections that depend on temperature and density. These new solutions solve for a variable Eddington factor (VEF) across the shock domain, which allows for interesting physics not seen before in radiative-shock solutions. Comparisons are made with the grey nonequilibrium-diffusion radiative-shock solutions of Lowrie and Edwards [1], which assumed that the Eddington factor is constant across the shock domain. It is our experience that the local Mach number is monotonic when producing nonequilibrium-diffusion solutions, but that this monotonicity may disappear while integrating the precursor region to produce Sn-transport solutions. For temperature- and density-dependent cross sections we show evidence of a spike in the VEF in the far upstream portion of the radiative-shock precursor. We show evidence of an adaptation zone in the precursor region, adjacent to the embedded hydrodynamic shock, as conjectured by Drake [2,3], and also confirm his expectation that the precursor temperatures adjacent to the Zel'dovich spike take values that are greater than the downstream post-shock equilibrium temperature. We also show evidence that the radiation energy density can be nonmonotonic under the Zel'dovich spike, which is indicative of anti-diffusive radiation flow as predicted by McClarren and Drake [4]. We compare the angle dependence of the radiation flow for the Sn-transport and nonequilibrium-diffusion radiation solutions, and show that there are considerable differences in the radiation flow between these models across the shock structure. Finally, we analyze the radiation flow to understand the cause of the adaptation zone, as well as the structure of the Sn-transport radiation-intensity solutions across the shock structure.

  1. Control of chilling tendency in grey cast iron reuse

    Directory of Open Access Journals (Sweden)

    Saliu Ojo Seidu

    2013-02-01

    Full Text Available In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation. With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test with cooling modulus of 0.45 cm (W3½ and 0.54 cm (W4. The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (% to 4.11 wt. (%. In the W4 wedge sample, at 2.0 wt. (% addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (% addition. With equivalent aspect ratio (cooling modulus in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.

  2. Control of chilling tendency in grey cast iron reuse

    Directory of Open Access Journals (Sweden)

    Saliu Ojo Seidu

    2012-01-01

    Full Text Available In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation. With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test with cooling modulus of 0.45 cm (W3½ and 0.54 cm (W4. The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (% to 4.11 wt. (%. In the W4 wedge sample, at 2.0 wt. (% addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (% addition. With equivalent aspect ratio (cooling modulus in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.

  3. Nonlinear photoacoustic spectroscopy of hemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Danielli, Amos; Maslov, Konstantin; Favazza, Christopher P.; Xia, Jun; Wang, Lihong V., E-mail: LHWANG@WUSTL.EDU [Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130 (United States)

    2015-05-18

    As light intensity increases in photoacoustic imaging, the saturation of optical absorption and the temperature dependence of the thermal expansion coefficient result in a measurable nonlinear dependence of the photoacoustic (PA) signal on the excitation pulse fluence. Here, under controlled conditions, we investigate the intensity-dependent photoacoustic signals from oxygenated and deoxygenated hemoglobin at varied optical wavelengths and molecular concentrations. The wavelength and concentration dependencies of the nonlinear PA spectrum are found to be significantly greater in oxygenated hemoglobin than in deoxygenated hemoglobin. These effects are further influenced by the hemoglobin concentration. These nonlinear phenomena provide insights into applications of photoacoustics, such as measurements of average inter-molecular distances on a nm scale or with a tuned selection of wavelengths, a more accurate quantitative PA tomography.

  4. Grey Markov chain and its application in drift prediction model of FOGs

    Institute of Scientific and Technical Information of China (English)

    Fan Chunling; Jin Zhihua; Tian Weifeng; Qian Feng

    2005-01-01

    A novel grey Markov chain predictive model is discussed to reduce drift influence on the output of fiber optical gyroscopes (FOGs) and to improve FOGs' measurement precision. The proposed method possesses advantages of grey model and Markov chain. It makes good use of dynamic modeling idea of the grey model to predict general trend of original data. Then according to the trend, states are divided so that it can overcome the disadvantage of high computational cost of state transition probability matrix in Markov chain. Moreover, the presented approach expands the applied scope of the grey model and makes it be fit for prediction of random data with bigger fluctuation. The numerical results of real drift data from a certain type FOG verify the effectiveness of the proposed grey Markov chain model powerfully. The Markov chain is also investigated to provide a comparison with the grey Markov chain model. It is shown that the hybrid grey Markov chain prediction model has higher modeling precision than Markov chain itself, which prove this proposed method is very applicable and effective.

  5. Ecotoxicological assessment of grey water treatment systems with Daphnia magna and Chironomus riparius.

    Science.gov (United States)

    Hernández Leal, L; Soeter, A M; Kools, S A E; Kraak, M H S; Parsons, J R; Temmink, H; Zeeman, G; Buisman, C J N

    2012-03-15

    In order to meet environmental quality criteria, grey water was treated in four different ways: 1) aerobic 2) anaerobic+aerobic 3) aerobic+activated carbon 4) aerobic+ozone. Since each treatment has its own specific advantages and disadvantages, the aim of this study was to compare the ecotoxicity of differently treated grey water using Chironomus riparius (96 h test) and Daphnia magna (48 h and 21d test) as test organisms. Grey water exhibited acute toxicity to both test organisms. The aerobic and combined anaerobic+aerobic treatment eliminated mortality in the acute tests, but growth of C. riparius was still affected by these two effluents. Post-treatment by ozone and activated carbon completely removed the acute toxicity from grey water. In the chronic toxicity test the combined anaerobic+aerobic treatment strongly affected D. magna population growth rate (47%), while the aerobic treatment had a small (9%) but significant effect. Hence, aerobic treatment is the best option for biological treatment of grey water, removing most of the toxic effects of grey water. If advanced treatment is required, the treatment with either ozone or GAC were shown to be very effective in complete removal of toxicity from grey water.

  6. Differential grey matter changes in sensorimotor cortex related to exceptional fine motor skills.

    Directory of Open Access Journals (Sweden)

    M Cornelia Stoeckel

    Full Text Available Functional changes in sensorimotor representation occur in response to use and lesion throughout life. Emerging evidence suggests that functional changes are paralleled by respective macroscopic structural changes. In the present study we used voxel-based morphometry to investigate sensorimotor cortex in subjects with congenitally malformed upper extremities. We expected increased or decreased grey matter to parallel the enlarged or reduced functional representations we reported previously. More specifically, we expected decreased grey matter values in lateral sensorimotor cortex related to compromised hand function and increased grey matter values in medial sensorimotor cortex due to compensatory foot use. We found a medial cluster of grey matter increase in subjects with frequent, hand-like compensatory foot use. This increase was predominantly seen for lateral premotor, supplementary motor, and motor areas and only marginally involved somatosensory cortex. Contrary to our expectation, subjects with a reduced number of fingers, who had shown shrinkage of the functional hand representation previously, did not show decreased grey matter values within lateral sensorimotor cortex. Our data suggest that functional plastic changes in sensorimotor cortex can be associated with increases in grey matter but may also occur in otherwise macroscopically normal appearing grey matter volumes. Furthermore, macroscopic structural changes in motor and premotor areas may be observed without respective changes in somatosensory cortex.

  7. Differential grey matter changes in sensorimotor cortex related to exceptional fine motor skills.

    Science.gov (United States)

    Stoeckel, M Cornelia; Morgenroth, Farina; Buetefisch, Cathrin M; Seitz, Rüdiger J

    2012-01-01

    Functional changes in sensorimotor representation occur in response to use and lesion throughout life. Emerging evidence suggests that functional changes are paralleled by respective macroscopic structural changes. In the present study we used voxel-based morphometry to investigate sensorimotor cortex in subjects with congenitally malformed upper extremities. We expected increased or decreased grey matter to parallel the enlarged or reduced functional representations we reported previously. More specifically, we expected decreased grey matter values in lateral sensorimotor cortex related to compromised hand function and increased grey matter values in medial sensorimotor cortex due to compensatory foot use. We found a medial cluster of grey matter increase in subjects with frequent, hand-like compensatory foot use. This increase was predominantly seen for lateral premotor, supplementary motor, and motor areas and only marginally involved somatosensory cortex. Contrary to our expectation, subjects with a reduced number of fingers, who had shown shrinkage of the functional hand representation previously, did not show decreased grey matter values within lateral sensorimotor cortex. Our data suggest that functional plastic changes in sensorimotor cortex can be associated with increases in grey matter but may also occur in otherwise macroscopically normal appearing grey matter volumes. Furthermore, macroscopic structural changes in motor and premotor areas may be observed without respective changes in somatosensory cortex.

  8. Multiple sclerosis deep grey matter: the relation between demyelination, neurodegeneration, inflammation and iron.

    Science.gov (United States)

    Haider, Lukas; Simeonidou, Constantina; Steinberger, Günther; Hametner, Simon; Grigoriadis, Nikolaos; Deretzi, Georgia; Kovacs, Gabor G; Kutzelnigg, Alexandra; Lassmann, Hans; Frischer, Josa M

    2014-12-01

    In multiple sclerosis (MS), diffuse degenerative processes in the deep grey matter have been associated with clinical disabilities. We performed a systematic study in MS deep grey matter with a focus on the incidence and topographical distribution of lesions in relation to white matter and cortex in a total sample of 75 MS autopsy patients and 12 controls. In addition, detailed analyses of inflammation, acute axonal injury, iron deposition and oxidative stress were performed. MS deep grey matter was affected by two different processes: the formation of focal demyelinating lesions and diffuse neurodegeneration. Deep grey matter demyelination was most prominent in the caudate nucleus and hypothalamus and could already be seen in early MS stages. Lesions developed on the background of inflammation. Deep grey matter inflammation was intermediate between low inflammatory cortical lesions and active white matter lesions. Demyelination and neurodegeneration were associated with oxidative injury. Iron was stored primarily within oligodendrocytes and myelin fibres and released upon demyelination. In addition to focal demyelinated plaques, the MS deep grey matter also showed diffuse and global neurodegeneration. This was reflected by a global reduction of neuronal density, the presence of acutely injured axons, and the accumulation of oxidised phospholipids and DNA in neurons, oligodendrocytes and axons. Neurodegeneration was associated with T cell infiltration, expression of inducible nitric oxide synthase in microglia and profound accumulation of iron. Thus, both focal lesions as well as diffuse neurodegeneration in the deep grey matter appeared to contribute to the neurological disabilities of MS patients.

  9. Grey-scale conversion X-ray mapping by EDS of multielement and multiphase layered microstructures

    DEFF Research Database (Denmark)

    Dahl, Kristian Vinter; Hald, John; Horsewell, Andy

    2007-01-01

    procedure for grey-scale conversion of energy dispersive spectroscopy X-ray maps has been developed, which is particularly useful for the plotting of line composition profiles across modified layered engineering surfaces. The method involves (a) the collection of grey-scale elemental maps, (b) th...... be considered as a rapid alternative to energy dispersive spectroscopy spectrum imaging. The composition profiles obtained may be conveniently compared with results of multicomponent thermodynamic modelling of interdiffusion.......procedure for grey-scale conversion of energy dispersive spectroscopy X-ray maps has been developed, which is particularly useful for the plotting of line composition profiles across modified layered engineering surfaces. The method involves (a) the collection of grey-scale elemental maps, (b......) the calculation of mean grey-scale levels along strips parallel to the layered microstructure and (c) the conversion of grey-scale line profiles into composition line profiles. As an example of the grey-scale conversion method and its advantages for multielement and multiphase layered microstructures...

  10. A new grey forecasting model based on BP neural network and Markov chain

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new grey forecasting model based on BP neural network and Markov chain was proposed. In order to combine the grey forecasting model with neural network, an important theorem that the grey differential equation is equivalent to the time response model, was proved by analyzing the features of grey forecasting model(GM(1,1)). Based on this, the differential equation parameters were included in the network when the BP neural network was constructed, and the neural network was trained by extracting samples from grey system's known data. When BP network was converged, the whitened grey differential equation parameters were extracted and then the grey neural network forecasting model (GNNM(1,1)) was built. In order to reduce stochastic phenomenon in GNNM(1,1), the state transition probability between two states was defined and the Markov transition matrix was established by building the residual sequences between grey forecasting and actual value. Thus, the new grey forecasting model(MNNGM(1,1)) was proposed by combining Markov chain with GNNM(1,1). Based on the above discussion, three different approaches were put forward for forecasting China electricity demands. By comparing GM(1,1) and GNNM(1,1) with the proposed model, the results indicate that the absolute mean error of MNNGM(1,1) is about 0.4 times of GNNM(1,1) and 0.2 times of GM(1,1), and the mean square error of MNNGM(1,1) is about 0.25 times of GNNM(1,1) and 0.1 times of GM(1,1).

  11. On arithmetic detection of grey pulses with application to Hawking radiation

    CERN Document Server

    Rosu, H C

    2002-01-01

    Micron-sized black holes do not necessarily have a constant horizon temperature distribution. The black hole remote-sensing problem means to find out the `surface' temperature distribution of a small black hole from the spectral measurement of its (Hawking) grey pulse. This problem has been previously considered by Rosu, who used Chen's modified Moebius inverse transform. Here, we hint on a Ramanujan generalization of Chen's modified MOebius inverse transform that may be considered as a special wavelet processing of the remote-sensed grey signal coming from a black hole or any other distant grey source

  12. Study on effectiveness evaluation of weapon systems based on grey relational analysis and TOPSIS

    Institute of Scientific and Technical Information of China (English)

    Gu Hui; Song Bifeng

    2009-01-01

    To evaluate the effectiveness of weapon systems, the advantages and disadvantages of grey relational analysis and TOPSIS for multiattribute decision-making is pointed out, and an effectiveness evaluation model of weapon systems by combining grey relational analysis and TOPSIS is proposed. The model aggregates the grey relational grade and the distance to a new integrated closeness and reflects not only the trend but also the situation of the alternative. The example illuminates that the model is effective for the effectiveness evaluation of weapon systems.

  13. Map Building for a Mobile Robot Based on Grey System Theory

    Institute of Scientific and Technical Information of China (English)

    王卫华; 席裕庚; 陈卫东

    2003-01-01

    In this paper, a new method for mobile robot map building based on grey system theory is presented, by which interpretation and integration of sonar readings can be solved robustly and efficiently. The conception of "grey number" is introduced to model and handle the uncertainty of sonar reading, A new data fusion approach based on grey system theory is proposed to construct environment model. Map building experiments are performed both on a platform of simulation and a real mobile robot. Experimental results show that our method is robust and accurate.

  14. International Conference on Grey Systems and intelligent Services (IEEE GSIS 2009)

    CERN Document Server

    Liu, Sifeng; Advances in Grey Systems Research

    2010-01-01

    This book contains contributions by some of the leading researchers in the area of grey systems theory and applications. All the papers included in this volume are selected from the contributions physically presented at the 2009 IEEE International Conference on Grey Systems and Intelligent Services, November 11 – 12, 2009, Nanjing, Jiangsu, People’s Republic of China. This event was jointly sponsored by IEEE Systems, Man, and Cybernetics Society, Natural Science Foundation of China, and Grey Systems Society of China. Additionally, Nanjing University of Aeronautics and Astronautics also invested heavily in this event with its direct and indirect financial and administrative supports.

  15. Grey gurnard ( Eutrigla gurnadus ) in the North Sea: an emerging key predator?

    DEFF Research Database (Denmark)

    Floeter, J.; Kempf, A.; Vinther, Morten

    2005-01-01

    as an "other predator" in the North Sea multispecies virtual population analysis (MSVPA) in 1997. The MSVPA results estimated grey gurnard to be responsible for approximately 60% of the total predation mortality on age-0 Atlantic cod (Gadus morhua). Long-term MSVPA predictions led to the extinction of North...... of high grey gurnard predation. Further, it was shown that grey gurnard predation had a significant top-down effect on whiting (Merlangius merlangus) and potentially also on cod recruitment, which was linked to the spatial distribution of the three species. Eventually, the implications of the results...

  16. Temporal behavior of low-amplitude two-photon screening-photovoltaic grey spatial solitons

    Institute of Scientific and Technical Information of China (English)

    JI Xuan-mang; JIANG Qi-chang; WANG Jin-lai; LIU Jin-song

    2011-01-01

    The time-dependent formation of one-dimensional two-photon screening-photovoltaic (PV) grey spatial solitons under low-amplitude conditions is presented theoretically. The time-dependent propagation equation of two-photon screening- photovoltaic solitons is obtained by the numerical method. The results indicate that as the time evolves, the intensity width of grey screening-photovoltaic spatial solitons decreases monotonously to a minimum value towards the steady state. The higher the ratio of soliton peak intensity to the dark irradiation intensity, the narrower the width of grey solitons within the propagation time.

  17. Nonlinear resonances

    CERN Document Server

    Rajasekar, Shanmuganathan

    2016-01-01

    This introductory text presents the basic aspects and most important features of various types of resonances and anti-resonances in dynamical systems. In particular, for each resonance, it covers the theoretical concepts, illustrates them with case studies, and reviews the available information on mechanisms, characterization, numerical simulations, experimental realizations, possible quantum analogues, applications and significant advances made over the years. Resonances are one of the most fundamental phenomena exhibited by nonlinear systems and refer to specific realizations of maximum response of a system due to the ability of that system to store and transfer energy received from an external forcing source. Resonances are of particular importance in physical, engineering and biological systems - they can prove to be advantageous in many applications, while leading to instability and even disasters in others. The book is self-contained, providing the details of mathematical derivations and techniques invo...

  18. Nonlinear Dynamics

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    3.1 A Unified Nonlinear Feedback Functional Method for Study Both Control and Synchronization of Spatiotemporal Chaos Fang Jinqing Ali M. K. (Department of Physics, The University of Lethbridge,Lethbridge, Alberta T1K 3M4,Canada) Two fundamental questions dominate future chaos control theories.The first is the problem of controlling hyperchaos in higher dimensional systems.The second question has yet to be addressed:the problem of controlling spatiotemporal chaos in a spatiotemporal system.In recent years, control and synchronization of spatiotemporal chaos and hyperchaos have became a much more important and challenging subject. The reason for this is the control and synchronism of such behaviours have extensive and great potential of interdisciplinary applications, such as security communication, information processing, medicine and so on. However, this subject is not much known and remains an outstanding open.

  19. Thermal Error Modelling of the Spindle Using Neurofuzzy Systems

    Directory of Open Access Journals (Sweden)

    Jingan Feng

    2016-01-01

    Full Text Available This paper proposes a new combined model to predict the spindle deformation, which combines the grey models and the ANFIS (adaptive neurofuzzy inference system model. The grey models are used to preprocess the original data, and the ANFIS model is used to adjust the combined model. The outputs of the grey models are used as the inputs of the ANFIS model to train the model. To evaluate the performance of the combined model, an experiment is implemented. Three Pt100 thermal resistances are used to monitor the spindle temperature and an inductive current sensor is used to obtain the spindle deformation. The experimental results display that the combined model can better predict the spindle deformation compared to BP network, and it can greatly improve the performance of the spindle.

  20. Nonlinear Materials Characterization Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Nonlinear Materials Characterization Facility conducts photophysical research and development of nonlinear materials operating in the visible spectrum to protect...

  1. Grey Comprehensive Evaluation of Biomass Power Generation Project Based on Group Judgement

    Science.gov (United States)

    Xia, Huicong; Niu, Dongxiao

    2017-06-01

    The comprehensive evaluation of benefit is an important task needed to be carried out at all stages of biomass power generation projects. This paper proposed an improved grey comprehensive evaluation method based on triangle whiten function. To improve the objectivity of weight calculation result of only reference comparison judgment method, this paper introduced group judgment to the weighting process. In the process of grey comprehensive evaluation, this paper invited a number of experts to estimate the benefit level of projects, and optimized the basic estimations based on the minimum variance principle to improve the accuracy of evaluation result. Taking a biomass power generation project as an example, the grey comprehensive evaluation result showed that the benefit level of this project was good. This example demonstrates the feasibility of grey comprehensive evaluation method based on group judgment for benefit evaluation of biomass power generation project.

  2. Grey seal (Halichoerus grypus) predation on harbour seals (Phoca vitulina) on the island of Helgoland, Germany

    Science.gov (United States)

    van Neer, Abbo; Jensen, Lasse Fast; Siebert, Ursula

    2015-03-01

    The prey spectrum of grey seals has to date been described as largely consisting of different fish, cephalopod and shrimp species. On the German island of Helgoland Düne, where harbour seals (Phoca vitulina) and grey seals (Halichoerus grypus) co-occur, a young male grey seal was observed in 2013 and again in 2014 preying upon young harbour seals. A harbour seal carcass with severe traumatic lesions was retrieved and post-mortem examinations were performed. In the following weeks several carcasses showing similar lesions were found. Sightings of grey seals assumed to be preying on harbour porpoises have increased around the North Sea. Increased competition as well as individualised behaviour could explain the increased number of observations, but former cases of abnormal lesions of marine mammals attributed to for example predation by sharks or mechanical processes should be revisited with regard to the emerging knowledge.

  3. In vitro toxicity of grey MTA in comparison to white MTA on human periodontal ligament fibroblasts.

    Science.gov (United States)

    Al-Haj Ali, S N; Al-Jundi, S H; Ditto, D J

    2014-12-01

    This was to define and compare the in vitro toxicity of grey MTA with that of white MTA on cultured human periodontal ligament (PDL) fibroblasts. PDL cells were obtained from sound first permanent molars and cultured in Dulbecco's Modified Eagle's Medium. Cultures were subjected to different concentrations of grey and white MTA (0.5, 5, 50 and 500 µg/ml) for 24 h at 37 °C. Cells that were not exposed to grey or white MTA served as the negative control. In vitro toxicity was assessed using MTT assay. The results were compared using ANOVA and Tukey statistical tests (p MTA presented higher in vitro toxicity than grey MTA. However, the differences were almost insignificant (p > 0.05). Both colours of MTA are biocompatible since they were both able to preserve PDL fibroblasts for up to 24 h. MTA is as a promising alternative in pulpotomy of primary teeth.

  4. Sensory migraine aura is not associated with structural grey matter abnormalities

    DEFF Research Database (Denmark)

    Hougaard, Anders; Amin, Faisal Mohammad; Arngrim, Nanna

    2016-01-01

    Migraine with aura (MA) is characterized by cortical dysfunction. Frequent aura attacks may alter cerebral cortical structure in patients, or structural grey matter abnormalities may predispose MA patients to aura attacks. In the present study we aimed to investigate cerebral grey matter structure...... sensory aura regularly. We analysed high-resolution structural MR images using two complimentary approaches and compared patients with and without sensory aura. Patients were also compared to controls. We found no differences of grey matter density or cortical thickness between patients with and without...... sensory aura and no differences for the cortical visual areas between patients and controls. The somatosensory cortex was thinner in patients (1.92 mm vs. 1.96 mm, P = 0.043) and the anterior cingulate cortex of patients had a decreased grey matter density (P = 0.039) compared to controls...

  5. Postoperative increase in grey matter volume in visual cortex after unilateral cataract surgery

    DEFF Research Database (Denmark)

    Lou, Astrid R.; Madsen, Kristoffer Hougaard; Julian, Hanne O.

    2013-01-01

    surgery induces a regional increase in grey matter in areas V1 and V2 of the visual cortex. Results:  In all patients, cataract surgery immediately improved visual acuity, contrast sensitivity and mean sensitivity in the visual field of the operated eye. The improvement in vision was stable throughout...... the 6 weeks after operation. VBM revealed a regional expansion of grey matter volume in area V2 contralateral to the operated eye during the 6-week period after surgery. Individual increases in grey matter were predicted by the symmetry in visual acuity between the operated eye and nonoperated eye....... The more symmetrical visual acuity became after unilateral cataract surgery, the more pronounced was the grey matter increase in visual cortex. Conclusion:  The data suggest that cataract surgery triggered a use-dependent structural plasticity in V2 presumably through improved binocular integration...

  6. An Optimized Grey GM(2,1 Model and Forecasting of Highway Subgrade Settlement

    Directory of Open Access Journals (Sweden)

    Ning Xu

    2015-01-01

    Full Text Available Grey prediction technique is a useful tool for few data analysis and short term forecasting. GM(2,1 model is one of the most important grey models. For improving the precision and prediction ability, we proposed a structure optimized GM(2,1 model, namely, SOGM(2,1 model. This study contributes grey prediction theory on three points. First, SOGM(2,1 model utilizes background sequence and inverse accumulating generated sequence to construct new grey equation with optimized structure, and then estimation of parameters is derived based on least errors. Second, reflection equation is constructed and the solving process is derived with the time response function acquired. Third, we put forward a new method for establishing initial values of time response function. After that, the new model is used to predict highway settlement of an engineering assessment. Comparing with other models, the results show that SOGM(2,1 is effective and practicable to forecast.

  7. Research on Grey Sliding Mode Control of Motor System of Fruit Harvesting Manipulator Joint

    Directory of Open Access Journals (Sweden)

    Jueping Bu

    2015-03-01

    Full Text Available The sliding mode control algorithm based on grey prediction theory is proposed in this study, aiming at the uncertainties in the servo system of fruit harvesting robot and the external disturbances that may affect the control quality of conventional sliding mode control algorithm. The proposed algorithm uses the grey theory ability to unknown information data to establish the grey model to the uncertainty and real-time compensate the unmodeled dynamics and the interference signal of system. Meanwhile, an improved reaching law direction is proposed to resist chattering and improve control accuracy. The simulation results show that the proposed sliding mode control algorithm effectively predicts and compensates the unmodeled dynamics and disturbances signal in the DC motor servo system of the fruit harvesting robot and improves the control precision of controller which provides the theoretical basis for the industrial application based on the grey prediction theory of sliding mode control algorithm.

  8. Large nonlocal nonlinear optical response of castor oil

    Science.gov (United States)

    Souza, Rogério F.; Alencar, Márcio A. R. C.; Meneghetti, Mario R.; Hickmann, Jandir M.

    2009-09-01

    The nonlocal nonlinearity of castor oil was investigated using the Z-scan technique in the CW regime at 514 nm and in femtosecond regime at 810 nm. Large negative nonlinear refractive indexes of thermal origin, thermo-optical coefficients and degree of nonlocality were obtained for both laser excitation wavelengths. The results indicate that the electronic part of the nonlinear refractive index and nonlinear absorption were negligible. Our results suggest that castor oil is promising candidate as a nonlinear medium for several nonlocal optical applications, such as in spatial soliton propagation, as well as a dispersant agent in the measurement of absorptive properties of nanoparticles.

  9. Thermal expansion of glassy polymers.

    Science.gov (United States)

    Davy, K W; Braden, M

    1992-01-01

    The thermal expansion of a number of glassy polymers of interest in dentistry has been studied using a quartz dilatometer. In some cases, the expansion was linear and therefore the coefficient of thermal expansion readily determined. Other polymers exhibited non-linear behaviour and values appropriate to different temperature ranges are quoted. The linear coefficient of thermal expansion was, to a first approximation, a function of both the molar volume and van der Waal's volume of the repeating unit.

  10. GREY CLASSIFICATION FOR EVALUATING THE STABILITY OF DANGEROUS ROCK-BLOCK MASSES

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper introduces a grey classification method for evaluating the stability of dangerous rockblock masses according to the Grey System Theory. This method is applied to the stability of the V# dangerous rockblock masses of Qingjiang water conservancy project, and better results are abtained. The method which is advanced in the article is very single and practical, and it can meet all kinds of project′s demands.

  11. Lithium-ion battery remaining useful life prediction based on grey support vector machines

    Directory of Open Access Journals (Sweden)

    Xiaogang Li

    2015-12-01

    Full Text Available In this article, an improved grey prediction model is proposed to address low-accuracy prediction issue of grey forecasting model. The first step is using a trigonometric function to transform the original data sequence to smooth the data, which is called smoothness of grey prediction model, and then a grey support vector machine model by integrating the improved grey model with support vector machine is introduced. At the initial stage of the model, trigonometric functions and accumulation generation operation can be used to preprocess the data, which enhances the smoothness of the data and reduces the associated randomness. In addition, support vector machine is implemented to establish a prediction model for the pre-processed data and select the optimal model parameters via genetic algorithms. Finally, the data are restored through the ‘regressive generate’ operation to obtain the forecasting data. To prove that the grey support vector machine model is superior to the other models, the battery life data from the Center for Advanced Life Cycle Engineering are selected, and the presented model is used to predict the remaining useful life of the battery. The predicted result is compared to that of grey model and support vector machines. For a more intuitive comparison of the three models, this article quantifies the root mean square errors for these three different models in the case of different ratio of training samples and prediction samples. The results show that the effect of grey support vector machine model is optimal, and the corresponding root mean square error is only 3.18%.

  12. Crop patterns and habitat preferences of the grey partridge farmland bird

    OpenAIRE

    Joannon, Alexandre; Bro, E.; Thenail, Claudine; Baudry, Jacques

    2008-01-01

    Agricultural changes such as intensification and specialization are thought to be the major source of the severe decline of farmland bird populations observed on large spatial scales and over long time spans in Europe. We studied farmers’ practices at a local level on 22 farms from the Beauce area, France, with regard to habitat preferences of grey partridge, Perdix perdix L.We focused on the study of vegetation cover because it influences grey partridge’s reproduction and survival. The resul...

  13. Hybrid Grey Forecasting Model for Iran’s Energy Consumption and Supply

    Directory of Open Access Journals (Sweden)

    Hamidreza Mostafaei

    2012-07-01

    Full Text Available Grey theory deals with systems that are characterized by poor information or for which information is lacking. This study presents an improved grey GM (1, 1 model, using a technique that combines residual modification with Markov Chain model. We use energy consumption and supply of Iran to test the accuracy of proposed model. The results show that the Markov Chain residual modification model achieves reliable and precise results.

  14. Combining Diffusion and Grey Models Based on Evolutionary Optimization Algorithms to Forecast Motherboard Shipments

    OpenAIRE

    Fu-Kwun Wang; Yu-Yao Hsiao; Ku-Kuang Chang

    2012-01-01

    It is important for executives to predict the future trends. Otherwise, their companies cannot make profitable decisions and investments. The Bass diffusion model can describe the empirical adoption curve for new products and technological innovations. The Grey model provides short-term forecasts using four data points. This study develops a combined model based on the rolling Grey model (RGM) and the Bass diffusion model to forecast motherboard shipments. In addition, we investigate evolutio...

  15. The Role of Google Scholar in Evidence Reviews and Its Applicability to Grey Literature Searching.

    Directory of Open Access Journals (Sweden)

    Neal Robert Haddaway

    Full Text Available Google Scholar (GS, a commonly used web-based academic search engine, catalogues between 2 and 100 million records of both academic and grey literature (articles not formally published by commercial academic publishers. Google Scholar collates results from across the internet and is free to use. As a result it has received considerable attention as a method for searching for literature, particularly in searches for grey literature, as required by systematic reviews. The reliance on GS as a standalone resource has been greatly debated, however, and its efficacy in grey literature searching has not yet been investigated. Using systematic review case studies from environmental science, we investigated the utility of GS in systematic reviews and in searches for grey literature. Our findings show that GS results contain moderate amounts of grey literature, with the majority found on average at page 80. We also found that, when searched for specifically, the majority of literature identified using Web of Science was also found using GS. However, our findings showed moderate/poor overlap in results when similar search strings were used in Web of Science and GS (10-67%, and that GS missed some important literature in five of six case studies. Furthermore, a general GS search failed to find any grey literature from a case study that involved manual searching of organisations' websites. If used in systematic reviews for grey literature, we recommend that searches of article titles focus on the first 200 to 300 results. We conclude that whilst Google Scholar can find much grey literature and specific, known studies, it should not be used alone for systematic review searches. Rather, it forms a powerful addition to other traditional search methods. In addition, we advocate the use of tools to transparently document and catalogue GS search results to maintain high levels of transparency and the ability to be updated, critical to systematic reviews.

  16. Metazoan parasites of grey mullets (Teleostea: Mugilidae) from the Mistras Lagoon (Sardinia - western Mediterranean)

    OpenAIRE

    Merella, Paolo; Garippa, Giovanni

    2001-01-01

    A total of 127 specimens of grey mullets (Teleostea: Mugilidae) from the Mistras Lagoon (Sardinia - western Mediterranean) were examined for metazoan parasites. Five species of grey mullets were found: Chelon labrosus, Liza aurata, L. ramada, L. saliens and Mugil cephalus. Forty-one species of parasites were identified: 14 monogeneans, 5 crustaceans, 18 digeneans, 3 nematodes and 1 acanthocephalan; 26 of them being reported from Sardinia for the first time. Findings of faunal interest are: Er...

  17. Combining Diffusion and Grey Models Based on Evolutionary Optimization Algorithms to Forecast Motherboard Shipments

    OpenAIRE

    Fu-Kwun Wang; Yu-Yao Hsiao; Ku-Kuang Chang

    2012-01-01

    It is important for executives to predict the future trends. Otherwise, their companies cannot make profitable decisions and investments. The Bass diffusion model can describe the empirical adoption curve for new products and technological innovations. The Grey model provides short-term forecasts using four data points. This study develops a combined model based on the rolling Grey model (RGM) and the Bass diffusion model to forecast motherboard shipments. In addition, we investigate evolutio...

  18. The Role of Google Scholar in Evidence Reviews and Its Applicability to Grey Literature Searching.

    Science.gov (United States)

    Haddaway, Neal Robert; Collins, Alexandra Mary; Coughlin, Deborah; Kirk, Stuart

    2015-01-01

    Google Scholar (GS), a commonly used web-based academic search engine, catalogues between 2 and 100 million records of both academic and grey literature (articles not formally published by commercial academic publishers). Google Scholar collates results from across the internet and is free to use. As a result it has received considerable attention as a method for searching for literature, particularly in searches for grey literature, as required by systematic reviews. The reliance on GS as a standalone resource has been greatly debated, however, and its efficacy in grey literature searching has not yet been investigated. Using systematic review case studies from environmental science, we investigated the utility of GS in systematic reviews and in searches for grey literature. Our findings show that GS results contain moderate amounts of grey literature, with the majority found on average at page 80. We also found that, when searched for specifically, the majority of literature identified using Web of Science was also found using GS. However, our findings showed moderate/poor overlap in results when similar search strings were used in Web of Science and GS (10-67%), and that GS missed some important literature in five of six case studies. Furthermore, a general GS search failed to find any grey literature from a case study that involved manual searching of organisations' websites. If used in systematic reviews for grey literature, we recommend that searches of article titles focus on the first 200 to 300 results. We conclude that whilst Google Scholar can find much grey literature and specific, known studies, it should not be used alone for systematic review searches. Rather, it forms a powerful addition to other traditional search methods. In addition, we advocate the use of tools to transparently document and catalogue GS search results to maintain high levels of transparency and the ability to be updated, critical to systematic reviews.

  19. Multi-objective optimization of cutting parameters in turning using grey relational analysis

    OpenAIRE

    2013-01-01

    This study presents optimization of performance characteristics in unidirectional glass fiber reinforced plastic composites using Taguchi method and Grey relational analysis. Performance characteristics such as surface roughness and material removal rate are optimized during rough cutting operation. Process parameters including tool nose radius, tool rake angle, feed rate, cutting speed, cutting environment and depth of cut are investigated using mixed L18 orthogonal array. Grey relation anal...

  20. The Role of Google Scholar in Evidence Reviews and Its Applicability to Grey Literature Searching

    Science.gov (United States)

    Haddaway, Neal Robert; Collins, Alexandra Mary; Coughlin, Deborah; Kirk, Stuart

    2015-01-01

    Google Scholar (GS), a commonly used web-based academic search engine, catalogues between 2 and 100 million records of both academic and grey literature (articles not formally published by commercial academic publishers). Google Scholar collates results from across the internet and is free to use. As a result it has received considerable attention as a method for searching for literature, particularly in searches for grey literature, as required by systematic reviews. The reliance on GS as a standalone resource has been greatly debated, however, and its efficacy in grey literature searching has not yet been investigated. Using systematic review case studies from environmental science, we investigated the utility of GS in systematic reviews and in searches for grey literature. Our findings show that GS results contain moderate amounts of grey literature, with the majority found on average at page 80. We also found that, when searched for specifically, the majority of literature identified using Web of Science was also found using GS. However, our findings showed moderate/poor overlap in results when similar search strings were used in Web of Science and GS (10–67%), and that GS missed some important literature in five of six case studies. Furthermore, a general GS search failed to find any grey literature from a case study that involved manual searching of organisations’ websites. If used in systematic reviews for grey literature, we recommend that searches of article titles focus on the first 200 to 300 results. We conclude that whilst Google Scholar can find much grey literature and specific, known studies, it should not be used alone for systematic review searches. Rather, it forms a powerful addition to other traditional search methods. In addition, we advocate the use of tools to transparently document and catalogue GS search results to maintain high levels of transparency and the ability to be updated, critical to systematic reviews. PMID:26379270

  1. Grey correlational and SSR analyses of cotton hybrids

    Institute of Scientific and Technical Information of China (English)

    Ma Xiongfeng; Zhang Wensheng; Yang Daigang; Zhou Xiaojian; Zhang Xianliang; Guo Ruilin; Wang Haifeng; Meng Qingqin; Pei Xiaoyu; Zhou Kehai

    2013-01-01

    Ten upland cotton strains exhibiting 3 fiber quality traits and 8 yield traits,were grown for two years in an investigation of the correlation between grey relational analysis (GRA) and genetic identity in heterosis of cot-ton hybrid. The aim was to establish the optimal approach for heterosis prediction and parent selection. Plant traits data were collected and analyzed for GRA. In addition,72 simple sequence repeat (SSR) markers were examined and 148 polymorphisms were detected. Correlation analysis of GRA,genetic identity,F1 fiber quality and yield heterosis was conducted. Significant differences were observed between the two analytic methods,whereas compa-rable predictions were given for yield heterosis. GRA for yield exhibited slightly higher correlation than genetic identity analysis,with a correlation coefficient of 0.49. GRA and genetic analysis exhibited overlapping yet dis-tinct advantages in heterosis prediction. Therefore,these analytical methods should be integrated to achieve the op-timal heterosis prediction and parent selection.

  2. Pathological differences between white and grey matter multiple sclerosis lesions.

    Science.gov (United States)

    Prins, Marloes; Schul, Emma; Geurts, Jeroen; van der Valk, Paul; Drukarch, Benjamin; van Dam, Anne-Marie

    2015-09-01

    Multiple sclerosis (MS) is a debilitating disease characterized by demyelination of the central nervous system (CNS), resulting in widespread formation of white matter lesions (WMLs) and grey matter lesions (GMLs). WMLs are pathologically characterized by the presence of immune cells that infiltrate the CNS, whereas these immune cells are barely present in GMLs. This striking pathological difference between WMLs and GMLs raises questions about the underlying mechanism. It is known that infiltrating leukocytes contribute to the generation of WMLs; however, since GMLs show a paucity of infiltrating immune cells, their importance in GML formation remains to be determined. Here, we review pathological characteristics of WMLs and GMLs, and suggest some possible explanations for the observed pathological differences. In our view, cellular and molecular characteristics of WM and GM, and local differences within WMLs and GMLs (in particular, in glial cell populations and the molecules they express), determine the pathway to demyelination. Further understanding of GML pathogenesis, considered to contribute to chronic MS, may have a direct impact on the development of novel therapeutic targets to counteract this progressive neurological disorder.

  3. EUPHEMISTIC AND DYSPHEMISTIC LANGUAGE IN FIFTY SHADES OF GREY TRILOGY

    Directory of Open Access Journals (Sweden)

    Raquel Sánchez Ruiz

    2015-01-01

    Full Text Available El impacto de la trilogía Cincuenta sombras de Grey ha trascendido la popularidad de las masas y ha ocupado la atención de la academia. Esto se ha evidenciado en investigaciones que abordan la obra desde diferentes perspectivas. Sin embargo, aunque las novelas han sido estudiadas con cierta profundidad, no se ha prestado demasiada atención a su uso del lenguaje. Considerando que las historias eróticas son un campo donde el eufemismo y el disfemismo proliferan, este artículo analiza el uso de ambos recursos así como el del x-femismo (cuasieufemismo y cuasidisfemismo en un corpus conformado por los libros de la mencionada trilogía. El presente estudio tiene dos propósitos: el primero, observar si el uso de estos mecanismos depende del género; el segundo, analizar cómo estos fenómenos se valen de la metáfora y la metonimia para evitar mostrar una imagen negativa o, por el contrario, destacar un tabú. Las conclusiones demuestran que los protagonistas masculino y femenino emplean un lenguaje diferente y utilizan estos mecanismos verbales con diversas intenciones.

  4. Dysbiotic drift: mental health, environmental grey space, and microbiota.

    Science.gov (United States)

    Logan, Alan C

    2015-05-07

    Advances in research concerning the mental health implications of dietary patterns and select nutrients have been remarkable. At the same time, there have been rapid increases in the understanding of the ways in which non-pathogenic microbes can potentially influence many aspects of human health, including those in the mental realm. Discussions of nutrition and microbiota are often overlapping. A separate, yet equally connected, avenue of research is that related to natural (for example, green space) and built environments, and in particular, how they are connected to human cognition and behaviors. It is argued here that in Western industrial nations a 'disparity of microbiota' might be expected among the socioeconomically disadvantaged, those whom face more profound environmental forces. Many of the environmental forces pushing against the vulnerable are at the neighborhood level. Matching the developing microbiome research with existing environmental justice research suggests that grey space may promote dysbiosis by default. In addition, the influence of Westernized lifestyle patterns, and the marketing forces that drive unhealthy behaviors in deprived communities, might allow dysbiosis to be the norm rather than the exception in those already at high risk of depression, subthreshold (subsyndromal) conditions, and subpar mental health. If microbiota are indeed at the intersection of nutrition, environmental health, and lifestyle medicine (as these avenues pertain to mental health), then perhaps the rapidly evolving gut-brain-microbiota conversation needs to operate through a wider lens. In contrast to the more narrowly defined psychobiotic, the term eco-psychotropic is introduced.

  5. Genetic variability of grey snow mould (Typhula incarnata).

    Science.gov (United States)

    Vergara, Georgina V; Bughrara, Suleiman S; Jung, Geunhwa

    2004-11-01

    Randomly amplified polymorphic DNA (RAPD) markers were used to assess the genetic diversity of isolates of grey snow mould ('gray snow mold'), Typhula incarnata, taken from infected turfgrasses from 40 different locations in the northern USA. Data from 115 markers using 37 RAPD primers showed 48 % polymorphism. The distance coefficients between isolates indicate the wide genetic diversity of T. incarnata across the sample area. Dendrograms generated using neighbour-joining (NJ) bootstrap analyses showed three clades and suggest possible recent colonization from common founder groups. Partitioning of the genetic variance using analysis of molecular variance (AMOVA) of four groups based on geographic locations (Michigan, lower and upper peninsula; Minnesota; Wisconsin) showed that genetic variation attributable among groups and within groups was 12.67 and 87.33 %, respectively. No correlation was found between geographic distance and pairwise genetic distance of the groups. High outcrossing and sexual recombination of T. incarnata may well be key factors explaining the genetic variability as shown with the low Fixation index (FST) and high average of genetic diversity per locus within groups.

  6. Efficacy of conventional fungicides in controlling tomato grey mold

    Directory of Open Access Journals (Sweden)

    A. Mavandadi

    2016-02-01

    Full Text Available One of the important diseases of tomato plants is grey mold, which is caused by Botrytis cinerea. In this research, the effects of 10 fungicides on mycelial growth and conidia germination of B. cinerea were investigated. Results showed that carbendazim with a median inhibitory concentration (IC50 value of 0.1 mg/L had the highest inhibitory effect and bordeaux mixture with an IC50 value of 1096.9 mg/L had the lowest inhibitory effect. Benomyl with an IC50 value of 0.04 mg/L had the most visual effects, after 3 and 7 days, on mycelial growth of B. cinerea. The effect of fungicides on preventing fruit wound development caused by B. cinerea was investigated, too. In benomyl treatment, wound diameter on the fruits was 0.73 mm and in copper oxychloride treatment was 6.16 mm, showing the highest and the lowest effective fungicides in the prevention of wound expansion. Different strains of the fungus were collected from various areas in Isfahan province and the effect of the fungicides on their conidial germination was evaluated. Results revealed that the collected isolates had different susceptibility to the 10 tested fungicides.

  7. Nonlinear singular vectors and nonlinear singular values

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel concept of nonlinear singular vector and nonlinear singular value is introduced, which is a natural generalization of the classical linear singular vector and linear singular value to the nonlinear category. The optimization problem related to the determination of nonlinear singular vectors and singular values is formulated. The general idea of this approach is demonstrated by a simple two-dimensional quasigeostrophic model in the atmospheric and oceanic sciences. The advantage and its applications of the new method to the predictability, ensemble forecast and finite-time nonlinear instability are discussed. This paper makes a necessary preparation for further theoretical and numerical investigations.

  8. Effects of parasitism and morphology on squirrelpox virus seroprevalence in grey squirrels (Sciurus carolinensis.

    Directory of Open Access Journals (Sweden)

    Natasha E McGowan

    Full Text Available Invasive species have been cited as major causes of population extinctions in several animal and plant classes worldwide. The North American grey squirrel (Sciurus carolinensis has a major detrimental effect on native red squirrel (Sciurus vulgaris populations across Britain and Ireland, in part because it can be a reservoir host for the deadly squirrelpox virus (SQPV. Whilst various researchers have investigated the epizootiology of SQPV disease in grey squirrels and have modelled the consequent effects on red squirrel populations, less work has examined morphological and physiological characteristics that might make individual grey squirrels more susceptible to contracting SQPV. The current study investigated the putative relationships between morphology, parasitism, and SQPV exposure in grey squirrels. We found geographical, sex, and morphological differences in SQPV seroprevalence. In particular, larger animals, those with wide zygomatic arch widths (ZAW, males with large testes, and individuals with concurrent nematode and/or coccidial infections had an increased seroprevalence of SQPV. In addition, males with larger spleens, particularly those with narrow ZAW, were more likely to be exposed to SQPV. Overall these results show that there is variation in SQPV seroprevalence in grey squirrels and that, consequently, certain individual, or populations of, grey squirrels might be more responsible for transmitting SQPV to native red squirrel populations.

  9. Whole genome grey and white matter DNA methylation profiles in dorsolateral prefrontal cortex.

    Science.gov (United States)

    Sanchez-Mut, Jose Vicente; Heyn, Holger; Vidal, Enrique; Delgado-Morales, Raúl; Moran, Sebastian; Sayols, Sergi; Sandoval, Juan; Ferrer, Isidre; Esteller, Manel; Gräff, Johannes

    2017-01-20

    The brain's neocortex is anatomically organized into grey and white matter, which are mainly composed by neuronal and glial cells, respectively. The neocortex can be further divided in different Brodmann areas according to their cytoarchitectural organization, which are associated with distinct cortical functions. There is increasing evidence that brain development and function are governed by epigenetic processes, yet their contribution to the functional organization of the neocortex remains incompletely understood. Herein, we determined the DNA methylation patterns of grey and white matter of dorsolateral prefrontal cortex (Brodmann area 9), an important region for higher cognitive skills that is particularly affected in various neurological diseases. For avoiding interindividual differences, we analyzed white and grey matter from the same donor using whole genome bisulfite sequencing, and for validating their biological significance, we used Infinium HumanMethylation450 BeadChip and pyrosequencing in ten and twenty independent samples, respectively. The combination of these analysis indicated robust grey-white matter differences in DNA methylation. What is more, cell type-specific markers were enriched among the most differentially methylated genes. Interestingly, we also found an outstanding number of grey-white matter differentially methylated genes that have previously been associated with Alzheimer's, Parkinson's, and Huntington's disease, as well as Multiple and Amyotrophic lateral sclerosis. The data presented here thus constitute an important resource for future studies not only to gain insight into brain regional as well as grey and white matter differences, but also to unmask epigenetic alterations that might underlie neurological and neurodegenerative diseases.

  10. Towards a Holistic Cortical Thickness Descriptor: Heat Kernel-Based Grey Matter Morphology Signatures.

    Science.gov (United States)

    Wang, Gang; Wang, Yalin

    2017-02-15

    In this paper, we propose a heat kernel based regional shape descriptor that may be capable of better exploiting volumetric morphological information than other available methods, thereby improving statistical power on brain magnetic resonance imaging (MRI) analysis. The mechanism of our analysis is driven by the graph spectrum and the heat kernel theory, to capture the volumetric geometry information in the constructed tetrahedral meshes. In order to capture profound brain grey matter shape changes, we first use the volumetric Laplace-Beltrami operator to determine the point pair correspondence between white-grey matter and CSF-grey matter boundary surfaces by computing the streamlines in a tetrahedral mesh. Secondly, we propose multi-scale grey matter morphology signatures to describe the transition probability by random walk between the point pairs, which reflects the inherent geometric characteristics. Thirdly, a point distribution model is applied to reduce the dimensionality of the grey matter morphology signatures and generate the internal structure features. With the sparse linear discriminant analysis, we select a concise morphology feature set with improved classification accuracies. In our experiments, the proposed work outperformed the cortical thickness features computed by FreeSurfer software in the classification of Alzheimer's disease and its prodromal stage, i.e., mild cognitive impairment, on publicly available data from the Alzheimer's Disease Neuroimaging Initiative. The multi-scale and physics based volumetric structure feature may bring stronger statistical power than some traditional methods for MRI-based grey matter morphology analysis.

  11. Mapping joint grey and white matter reductions in Alzheimer's disease using joint independent component analysis.

    Science.gov (United States)

    Guo, Xiaojuan; Han, Yuan; Chen, Kewei; Wang, Yan; Yao, Li

    2012-12-07

    Alzheimer's disease (AD) is a neurodegenerative disease concomitant with grey and white matter damages. However, the interrelationship of volumetric changes between grey and white matter remains poorly understood in AD. Using joint independent component analysis, this study identified joint grey and white matter volume reductions based on structural magnetic resonance imaging data to construct the covariant networks in twelve AD patients and fourteen normal controls (NC). We found that three networks showed significant volume reductions in joint grey-white matter sources in AD patients, including (1) frontal/parietal/temporal-superior longitudinal fasciculus/corpus callosum, (2) temporal/parietal/occipital-frontal/occipital, and (3) temporal-precentral/postcentral. The corresponding expression scores distinguished AD patients from NC with 85.7%, 100% and 85.7% sensitivity for joint sources 1, 2 and 3, respectively; 75.0%, 66.7% and 75.0% specificity for joint sources 1, 2 and 3, respectively. Furthermore, the combined source of three significant joint sources best predicted the AD/NC group membership with 92.9% sensitivity and 83.3% specificity. Our findings revealed joint grey and white matter loss in AD patients, and these results can help elucidate the mechanism of grey and white matter reductions in the development of AD.

  12. Socioeconomic status and the cerebellar grey matter volume. Data from a well-characterised population sample.

    Science.gov (United States)

    Cavanagh, Jonathan; Krishnadas, Rajeev; Batty, G David; Burns, Harry; Deans, Kevin A; Ford, Ian; McConnachie, Alex; McGinty, Agnes; McLean, Jennifer S; Millar, Keith; Sattar, Naveed; Shiels, Paul G; Tannahill, Carol; Velupillai, Yoga N; Packard, Chris J; McLean, John

    2013-12-01

    The cerebellum is highly sensitive to adverse environmental factors throughout the life span. Socioeconomic deprivation has been associated with greater inflammatory and cardiometabolic risk, and poor neurocognitive function. Given the increasing awareness of the association between early-life adversities on cerebellar structure, we aimed to explore the relationship between early life (ESES) and current socioeconomic status (CSES) and cerebellar volume. T1-weighted MRI was used to create models of cerebellar grey matter volumes in 42 adult neurologically healthy males selected from the Psychological, Social and Biological Determinants of Ill Health study. The relationship between potential risk factors, including ESES, CSES and cerebellar grey matter volumes were examined using multiple regression techniques. We also examined if greater multisystem physiological risk index-derived from inflammatory and cardiometabolic risk markers-mediated the relationship between socioeconomic status (SES) and cerebellar grey matter volume. Both ESES and CSES explained the greatest variance in cerebellar grey matter volume, with age and alcohol use as a covariate in the model. Low CSES explained additional significant variance to low ESES on grey matter decrease. The multisystem physiological risk index mediated the relationship between both early life and current SES and grey matter volume in cerebellum. In a randomly selected sample of neurologically healthy males, poorer socioeconomic status was associated with a smaller cerebellar volume. Early and current socioeconomic status and the multisystem physiological risk index also apparently influence cerebellar volume. These findings provide data on the relationship between socioeconomic deprivation and a brain region highly sensitive to environmental factors.

  13. Grey leaves in an alpine plant: a cryptic colouration to avoid attack?

    Science.gov (United States)

    Niu, Yang; Chen, Gao; Peng, De-Li; Song, Bo; Yang, Yang; Li, Zhi-Min; Sun, Hang

    2014-08-01

    Cryptic colouration is a common predation-avoidance strategy in animals that is postulated to occur in plants, but few experimental studies have rigorously tested this hypothesis. We investigated the colouration of Corydalis benecincta, an alpine plant with remarkably dimorphic leaf colours (grey and green), based on a cost-benefit analysis. First we tested the premise that herbivores (Parnassius butterflies) cannot distinguish grey leaves from a scree background by spectrographic measurements and by estimating discriminability between leaves and scree using a butterfly colour vision model. Then we estimated the potential costs of inconspicuousness by comparing the photosynthetic performance and visual attractiveness to flower visitors of the two colour morphs. Finally, we examined the potential benefits of inconspicuousness by comparing damage, survivorship and female reproductive success. It is difficult for herbivores to distinguish grey-coloured morphs against the background. This grey colour originates in a combination of anthocyanins and chlorophylls. The two colour morphs had similar photosynthetic performance, visual attractiveness and female reproductive success. However, grey morphs had significantly lower herbivore damage and higher survivorship. Grey leaves benefit C. benecincta by reducing herbivory with low investment in anthocyanin synthesis, and little cost on photosynthesis and mating opportunity. This cryptic colouration may have evolved through selection pressure imposed by visually foraging herbivores.

  14. Data processing of small samples based on grey distance information approach

    Institute of Scientific and Technical Information of China (English)

    Ke Hongfa; Chen Yongguang; Liu Yi

    2007-01-01

    Data processing of small samples is an important and valuable research problem in the electronic equipment test.Because it is difficult and complex to determine the probability distribution of small samples, it is difficult to use the traditional probability theory to process the samples and assess the degree of uncertainty.Using the grey relational theory and the norm theory, the grey distance information approach, which is based on the grey distance information quantity of a sample and the average grey distance information quantity of the samples, is proposed in this article.The definitions of the grey distance information quantity of a sample and the average grey distance information quantity of the samples, with their characteristics and algorithms, are introduced.The correlative problems, including the algorithm of estimated value, the standard deviation, and the acceptance and rejection criteria of the samples and estimated results, are also proposed.Moreover, the information whitening ratio is introduced to select the weight algorithm and to compare the different samples.Several examples are given to demonstrate the application of the proposed approach.The examples show that the proposed approach, which has no demand for the probability distribution of small samples, is feasible and effective.

  15. A Novel Adaptive Grey Verhulst Model for Network Security Situation Prediction

    Directory of Open Access Journals (Sweden)

    Yu-Beng Leau

    2016-01-01

    Full Text Available Recently, researchers have shown an increased interest in predicting the situation of incoming security situation for organization’s network. Many prediction models have been produced for this purpose, but many of these models have various limitations in practical applications. In addition, literature shows that far too little attention has been paid in utilizing the grey Verhulst model predicting network security situation although it has demonstrated satisfactory results in other fields. By considering the nature of intrusion attacks and shortcomings of traditional grey Verhulst model, this paper puts forward an adaptive grey Verhust model with adjustable generation sequence to improve the prediction accuracy. The proposed model employs the combination methods of Trapezoidal rule and Simpson’s 1/3rd rule to obtain the background value in grey differential equation which will directly influence the forecast result. In order to verify the performance of the proposed model, benchmarked datasets, DARPA 1999 and 2000 have been used to highlight the efficacy of the proposed model. The results show that the proposed adaptive grey Verhulst surpassed GM(1,1 and traditional grey Verhulst in forecasting incoming security situation in a network.

  16. Assessing the Eutrophication of Shengzhong Reservoir Based on Grey Clustering Method

    Institute of Scientific and Technical Information of China (English)

    Pan An; Hu Lihui; Li Tesong; Li Chengzhu

    2009-01-01

    Reservoir water environment is a grey system.The grey clustering method is applied to assessing the reservoir water envi-ronment to establish a relatively complete model suitable for the reservoir eutrophication evaluation and appropriately evaluate the quality of reservoir water, providing evidence for reservoir man-agement.According to Chiua's lakes and reservoir eutrophication criteria and the characteristics of China's entrophication, as well as certain evaluation indices, the degree of eutrophication is classified into six categories with the utilization of grey classified whitening weight function to represent the boundaries of classification, to determine the clustering weight and clustering coefficient of each index in grey classifications, and the classification of each cluster-lag object.The comprehensive evaluation of reservoir eutrophica-tion is established on such a foundation, with Sichuan Shengzhong Reservoir as the survey object and the analysis of the data attained by several typical monitoring points there in 2006.It is found that eutrophication of Tiebian Power Generation Station, Guoyu-anchang and Dashiqiao Bridge is the heaviest, Tielusi and Qing-gangya the second, and Lijiaba the least.The eutrophication of this reservoir is closely relevant to the irrational exploitation in its surrounding areas, especially to the aggravation of the non-point source pollution and the increase of net-culture fishing.Therefore, it is feasible to use grey clustering in environment quality evalu-ation, and the point lies in the correct division of grey whitening function

  17. Mortality at Music Festivals: Academic and Grey Literature for Case Finding.

    Science.gov (United States)

    Turris, Sheila A; Lund, Adam

    2017-02-01

    Deaths at music festivals are not infrequently reported in the media; however, the true mortality burden is difficult to determine as the deaths are not yet systematically documented in the academic literature. This was a literature search for case examples using academic and gray literature sources, employing both retrospective and prospective searches of media sources from 1999-2014. The gray literature documents a total of 722 deaths, including traumatic (594/722; 82%) and non-traumatic (128/722; 18%) causes. Fatalities were caused by trampling (n=479), motor-vehicle-related (n=39), structural collapses (n=28), acts of terror (n=26), drowning (n=8), assaults (n=6), falls (n=5), hanging (n=2), and thermal injury (n=2). Non-traumatic deaths included overdoses (n=96/722; 13%), environmental causes (n=8/722; 1%), natural causes (n=10/722; 1%), and unknown/not reported (n=14/722; 2%). The majority of non-trauma-related deaths were related to overdose (75%). The academic literature documents trauma-related deaths (n=368) and overdose-related deaths (n=12). One hundred percent of the trauma-related deaths reported in the academic literature also were reported in the gray literature (n=368). Mortality rates cannot be reported as the total attendance at events is not known. The methodology presented in this manuscript confirms that deaths occur not uncommonly at music festivals, and it represents a starting point in the documentation and surveillance of mortality. Turris SA , Lund A . Mortality at music festivals: academic and grey literature for case finding. Prehosp Disaster Med. 2017;32(1):58-63.

  18. Analysis of the Influence of Thermal Effect on Z-Scan Measurements with a Nanosecond Pulse Laser

    Institute of Scientific and Technical Information of China (English)

    TIAN Jian-Guo; WANG Hao-Hua; ZHOU Wen-Yuan; LI Tao; ZHANG Chun-Ping; ZHANG Guang-Yin

    2000-01-01

    The influence of thermally induced optical nonlinearities on Z-scan measurements with a nanosecond pulse laser is investigated theoretically. The results demonstrate that thermal effect plays an important role in certain circumstance. As an example, the optical nonlinearities of CS2 with an adjustable linear absorption coefficient which is used to alter the magnitude of thermally induced optical nonlinearities are analysed, and the results show that thermal effect even makes the change of the sign of optical nonlinearities.

  19. Temperature effects in a nonlinear model of monolayer Scheibe aggregates

    DEFF Research Database (Denmark)

    Bang, Ole; Christiansen, Peter Leth; If, F.

    1994-01-01

    A nonlinear dynamical model of molecular monolayers arranged in Scheibe aggregates is derived from a proper Hamiltonian. Thermal fluctuations of the phonons are included. The resulting equation for the excitons is the two dimensional nonlinear Schrodinger equation with noise. Two limits...

  20. Macrostructural alterations of subcortical grey matter in psychogenic erectile dysfunction.

    Directory of Open Access Journals (Sweden)

    Nicoletta Cera

    Full Text Available Psychogenic erectile dysfunction (ED has been defined as the persistent inability to attain and maintain an erection sufficient to permit sexual performance. It shows a high incidence and prevalence among men, with a significant impact on the quality of life. Few neuroimaging studies have investigated the cerebral basis of erectile dysfunctions observing the role played by prefrontal, cingulate, and parietal cortices during erotic stimulation. In spite of the well-known involvement of subcortical regions such as hypothalamus and caudate nucleus in male sexual response, and the key role of nucleus accumbens in pleasure and reward, poor attention was paid to their role in male sexual dysfunction. In this study, we determined the presence of grey matter (GM atrophy patterns in subcortical structures such as amygdala, hippocampus, nucleus accumbens, caudate nucleus, putamen, pallidum, thalamus, and hypothalamus in patients with psychogenic ED and healthy men. After Rigiscan evaluation, urological, general medical, metabolic and hormonal, psychological and psychiatric assessment, 17 outpatients with psychogenic ED and 25 healthy controls were recruited for structural MRI session. Significant GM atrophy of nucleus accumbens was observed bilaterally in patients with respect to controls. Shape analysis showed that this atrophy was located in the left medial-anterior and posterior portion of accumbens. Left nucleus accumbens volumes in patients correlated with low erectile functioning as measured by IIEF-5 (International Index of Erectile Function. In addition, a GM atrophy of left hypothalamus was also observed. Our results suggest that atrophy of nucleus accumbens plays an important role in psychogenic erectile dysfunction. We believe that this change can influence the motivation-related component of sexual behavior. Our findings help to elucidate a neural basis of psychogenic erectile dysfunction.