Thermally generated metals for plasmonic coloring and surface-enhanced Raman sensing

Science.gov (United States)

Huang, Zhenping; Chen, Jian; Liu, Guiqiang; Wang, Yan; Liu, Yi; Tang, Li; Liu, Zhengqi

2018-03-01

Spectral coloring glass and its application on the surface-enhanced Raman scattering are demonstrated experimentally via a simple and moderate heat-treating of the top ultrathin gold film to create discrete nanoparticles, which can produce localized surface plasmon resonances and strong plasmonic near-field coupling effects. Ultrathin metal films with a wide range of thicknesses are investigated by different heat-treatment processes. The annealed metal films have been demonstrated with a series of spectral coloring responses. Moreover, the microscopy images of the metal film structures confirm the formation of distinct geometry features in these operation procedures. Densely packed nanoparticles are observed for the ultrathin metal film with the single-digit level of thickness. With increasing the film thickness over 10 nm, metallic clusters and porous morphologies can be obtained. Importantly, the metallic resonators can provide enhanced Raman scattering with the detection limit down to 10 - 7 molL - 1 of Rhodamine 6G molecules due to the excitation of plasmon resonances and strong near-field coupling effects. These features hold great potential for large-scale and low-cost production of colored glass and Raman substrate.

Percolation-enhanced nonlinear scattering from semicontinuous metal films

Science.gov (United States)

Breit, M.; von Plessen, G.; Feldmann, J.; Podolskiy, V. A.; Sarychev, A. K.; Shalaev, V. M.; Gresillon, S.; Rivoal, J. C.; Gadenne, P.

2001-03-01

Strongly enhanced second-harmonic generation (SHG), which is characterized by nearly isotropic distribution, is observed for gold-glass films near the percolation threshold. The diffuse-like SHG scattering, which can be thought of as nonlinear critical opalescence, is in sharp contrast with highly collimated linear reflection and transmission from these nanostructured semicontinuous metal films. Our observations, which can be explained by giant fluctuations of local nonlinear sources for SHG, verify recent predictions of percolation-enhanced nonlinear scattering.

Ultrafast nonlinear optical processes in metal-dielectric nanocomposites and nanostructures

Energy Technology Data Exchange (ETDEWEB)

Kim, Kwang-Hyon

2012-04-13

This work reports results of a theoretical study of nonlinear optical processes in metal-dielectric nanocomposites used for the increase of the nonlinear coefficients and for plasmonic field enhancement. The main results include the study of the transient saturable nonlinearity in dielectric composites doped with metal nanoparticles, its physical mechanism as well its applications in nonlinear optics. For the study of the transient response, a time-depending equation for the dielectric function of the nanocomposite using the semi-classical two-temperature model is derived. By using this approach, we study the transient nonlinear characteristics of these materials in comparison with preceding experimental measurements. The results show that these materials behave as efficient saturable absorbers for passive mode-locking of lasers in the spectral range from the visible to near IR. We present results for the modelocked dynamics in short-wavelength solid-state and semiconductor disk lasers; in this spectral range other efficient saturable absorbers do not exist. We suggest a new mechanism for the realization of slow light phenomenon by using glasses doped with metal nanoparticles in a pump-probe regime near the plasmonic resonance. Furthermore, we study femtosecond plasmon generation by mode-locked surface plasmon polariton lasers with Bragg reflectors and metal-gain-absorber layered structures. In the final part of the thesis, we present results for high-order harmonic generation near a metallic fractal rough surface. The results show a possible reduction of the pump intensities by three orders of magnitudes and two orders of magnitudes higher efficiency compared with preceding experimental results by using bow-tie nanostructures.

Nonlinear optical properties of ultrathin metal layers

DEFF Research Database (Denmark)

Lysenko, Oleg

2016-01-01

This thesis presents experimental and theoretical studies of nonlinear propagation of ultrashort long-range surface plasmon polaritons in gold strip waveguides. The strip plasmonic waveguides are fabricated in house, and contain a gold layer, adhesion layers, and silicon dioxide cladding. The opt......This thesis presents experimental and theoretical studies of nonlinear propagation of ultrashort long-range surface plasmon polaritons in gold strip waveguides. The strip plasmonic waveguides are fabricated in house, and contain a gold layer, adhesion layers, and silicon dioxide cladding......-order nonlinear susceptibility of the plasmonic mode in the gold strip waveguides significantly depends on the metal layer thickness and laser pulse duration. This dependence is explained in detail in terms of the free-electron temporal dynamics in gold. The third-order nonlinear susceptibility of the gold layer...

SPP propagation in nonlinear glass-metal interface

KAUST Repository

Sagor, Rakibul Hasan; Alsunaidi, Mohammad A.; Ooi, Boon S.

2011-01-01

The non-linear propagation of Surface-Plasmon-Polaritons (SPP) in single interface of metal and chalcogenide glass (ChG) is considered. A time domain simulation algorithm is developed using the Finite Difference Time Domain (FDTD) method

ULTRAVIOLET COLOR-COLOR RELATION OF EARLY-TYPE GALAXIES AT 0.05 < z < 0.12

International Nuclear Information System (INIS)

Ree, Chang H.; Jeong, Hyunjin; Lee, Joon Hyeop; Kim, Sang Chul; Kyeong, Jaemann; Oh, Kyuseok; Chung, Chul

2012-01-01

We present the ultraviolet (UV) color-color relation of early-type galaxies (ETGs) in the nearby universe (0.05 < z < 0.12) to investigate the properties of hot stellar populations responsible for the UV excess (UVX). The initial sample of ETGs is selected by the spectroscopic redshift and the morphology parameter from the Sloan Digital Sky Survey (SDSS) Data Release 7, and then cross-matched with the Galaxy Evolution Explorer (GALEX) far-UV (FUV) and near-UV (NUV) GR6 data. The cross-matched ETG sample is further classified by their emission line characteristics in the optical spectra into quiescent, star-forming, and active galactic nucleus categories. Contaminations from early-type spiral galaxies, mergers, and morphologically disturbed galaxies are removed by visual inspection. By drawing the FUV-NUV (as a measure of UV spectral shape) versus FUV – r (as a measure of UVX strength) diagram for the final sample of ∼3700 quiescent ETGs, we find that the 'old and dead' ETGs consist of a well-defined sequence in UV colors, the 'UV red sequence', so that the stronger UVX galaxies should have a harder UV spectral shape systematically. However, the observed UV spectral slope is too steep to be reproduced by the canonical stellar population models in which the UV flux is mainly controlled by age or metallicity parameters. Moreover, 2 mag of color spreads both in FUV-NUV and FUV – r appear to be ubiquitous among any subsets in distance or luminosity. This implies that the UVX in ETGs could be driven by yet another parameter which might be even more influential than age or metallicity.

THE SLUGGS SURVEY: NGC 3115, A CRITICAL TEST CASE FOR METALLICITY BIMODALITY IN GLOBULAR CLUSTER SYSTEMS

International Nuclear Information System (INIS)

Brodie, Jean P.; Conroy, Charlie; Arnold, Jacob A.; Romanowsky, Aaron J.; Usher, Christopher; Forbes, Duncan A.; Strader, Jay

2012-01-01

Due to its proximity (9 Mpc) and the strongly bimodal color distribution of its spectroscopically well-sampled globular cluster (GC) system, the early-type galaxy NGC 3115 provides one of the best available tests of whether the color bimodality widely observed in GC systems generally reflects a true metallicity bimodality. Color bimodality has alternatively been attributed to a strongly nonlinear color-metallicity relation reflecting the influence of hot horizontal-branch stars. Here, we couple Subaru Suprime-Cam gi photometry with Keck/DEIMOS spectroscopy to accurately measure GC colors and a CaT index that measures the Ca II triplet. We find the NGC 3115 GC system to be unambiguously bimodal in both color and the CaT index. Using simple stellar population models, we show that the CaT index is essentially unaffected by variations in horizontal-branch morphology over the range of metallicities relevant to GC systems (and is thus a robust indicator of metallicity) and confirm bimodality in the metallicity distribution. We assess the existing evidence for and against multiple metallicity subpopulations in early- and late-type galaxies and conclude that metallicity bi/multimodality is common. We briefly discuss how this fundamental characteristic links directly to the star formation and assembly histories of galaxies.

THE SLUGGS SURVEY: NGC 3115, A CRITICAL TEST CASE FOR METALLICITY BIMODALITY IN GLOBULAR CLUSTER SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Brodie, Jean P.; Conroy, Charlie; Arnold, Jacob A.; Romanowsky, Aaron J. [University of California Observatories and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Usher, Christopher; Forbes, Duncan A. [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Strader, Jay, E-mail: brodie@ucolick.org [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

2012-11-10

Due to its proximity (9 Mpc) and the strongly bimodal color distribution of its spectroscopically well-sampled globular cluster (GC) system, the early-type galaxy NGC 3115 provides one of the best available tests of whether the color bimodality widely observed in GC systems generally reflects a true metallicity bimodality. Color bimodality has alternatively been attributed to a strongly nonlinear color-metallicity relation reflecting the influence of hot horizontal-branch stars. Here, we couple Subaru Suprime-Cam gi photometry with Keck/DEIMOS spectroscopy to accurately measure GC colors and a CaT index that measures the Ca II triplet. We find the NGC 3115 GC system to be unambiguously bimodal in both color and the CaT index. Using simple stellar population models, we show that the CaT index is essentially unaffected by variations in horizontal-branch morphology over the range of metallicities relevant to GC systems (and is thus a robust indicator of metallicity) and confirm bimodality in the metallicity distribution. We assess the existing evidence for and against multiple metallicity subpopulations in early- and late-type galaxies and conclude that metallicity bi/multimodality is common. We briefly discuss how this fundamental characteristic links directly to the star formation and assembly histories of galaxies.

Color image encryption based on Coupled Nonlinear Chaotic Map

International Nuclear Information System (INIS)

Mazloom, Sahar; Eftekhari-Moghadam, Amir Masud

2009-01-01

Image encryption is somehow different from text encryption due to some inherent features of image such as bulk data capacity and high correlation among pixels, which are generally difficult to handle by conventional methods. The desirable cryptographic properties of the chaotic maps such as sensitivity to initial conditions and random-like behavior have attracted the attention of cryptographers to develop new encryption algorithms. Therefore, recent researches of image encryption algorithms have been increasingly based on chaotic systems, though the drawbacks of small key space and weak security in one-dimensional chaotic cryptosystems are obvious. This paper proposes a Coupled Nonlinear Chaotic Map, called CNCM, and a novel chaos-based image encryption algorithm to encrypt color images by using CNCM. The chaotic cryptography technique which used in this paper is a symmetric key cryptography with a stream cipher structure. In order to increase the security of the proposed algorithm, 240 bit-long secret key is used to generate the initial conditions and parameters of the chaotic map by making some algebraic transformations to the key. These transformations as well as the nonlinearity and coupling structure of the CNCM have enhanced the cryptosystem security. For getting higher security and higher complexity, the current paper employs the image size and color components to cryptosystem, thereby significantly increasing the resistance to known/chosen-plaintext attacks. The results of several experimental, statistical analysis and key sensitivity tests show that the proposed image encryption scheme provides an efficient and secure way for real-time image encryption and transmission.

Color-magnitude diagrams for six metal-rich, low-latitude globular clusters

Science.gov (United States)

Armandroff, Taft E.

1988-01-01

Colors and magnitudes for stars on CCD frames for six metal-rich, low-latitude, previously unstudied globular clusters and one well-studied, metal-rich cluster (47 Tuc) have been derived and color-magnitude diagrams have been constructed. The photometry for stars in 47 Tuc are in good agreement with previous studies, while the V magnitudes of the horizontal-branch stars in the six program clusters do not agree with estimates based on secondary methods. The distances to these clusters are different from prior estimates. Redding values are derived for each program cluster. The horizontal branches of the program clusters all appear to lie entirely redwards of the red edge of the instability strip, as is normal for their metallicities.

Stress evaluation of metallic material under steady state based on nonlinear critically refracted longitudinal wave

Science.gov (United States)

Mao, Hanling; Zhang, Yuhua; Mao, Hanying; Li, Xinxin; Huang, Zhenfeng

2018-06-01

This paper presents the study of applying the nonlinear ultrasonic wave to evaluate the stress state of metallic materials under steady state. The pre-stress loading method is applied to guarantee components with steady stress. Three kinds of nonlinear ultrasonic experiments based on critically refracted longitudinal wave are conducted on components which the critically refracted longitudinal wave propagates along x, x1 and x2 direction. Experimental results indicate the second and third order relative nonlinear coefficients monotonically increase with stress, and the normalized relationship is consistent with simplified dislocation models, which indicates the experimental result is logical. The combined ultrasonic nonlinear parameter is proposed, and three stress evaluation models at x direction are established based on three ultrasonic nonlinear parameters, which the estimation error is below 5%. Then two stress detection models at x1 and x2 direction are built based on combined ultrasonic nonlinear parameter, the stress synthesis method is applied to calculate the magnitude and direction of principal stress. The results show the prediction error is within 5% and the angle deviation is within 1.5°. Therefore the nonlinear ultrasonic technique based on LCR wave could be applied to nondestructively evaluate the stress of metallic materials under steady state which the magnitude and direction are included.

Nonlinear absorption properties of some 1,4,8,11,15,18,22,25-octaalkylphthalocyanines and their metallated derivatives

OpenAIRE

BLAU, WERNER

2003-01-01

PUBLISHED The third-order nonlinear optical properties of a series of 15 unmetallated and metallated 1,4,8,11,15,18,22,25-octaalkylphthalocyanines have been investigated. The palladium-metallated compound is the strongest nonlinear absorber of the series, but, due to its comparatively high linear absorption coefficient, it exhibits a relatively low ratio of excited- to ground-state absorption cross-sections (?) when compared to the other compounds. The highest values for ? were found for d...

Dichotomous classification of black-colored metal using spectral analysis

Directory of Open Access Journals (Sweden)

Abramovich A.O.

2017-05-01

Full Text Available The task of detecting metal objects in different environments has always been important. To solve it metal detectors are used. They are designed to detect and identify objects that in their electric or magnetic properties different from the environment in which they are located. The most common among them are the metal detectors of the «detection of very low frequency» type (Very Low Frequency (VLF detectors. They use eddy current testing for detecting metal targets, which solves the problem of dichotomous distinction, that is a problem of splitting (or set into two parts (subsets: black or colored target. The target distinction is performed by a threshold level of the received signal. However, this approach does not allow to identify the type of target, if two samples of different metals are nearby. To overcome the above described limitations we propose another way of distinction based on the use of spectral analysis, which occurs in the metal detector antenna by Foucault current. We show that the problem of dichotomous distinction can be solved in just a measurement of width and area by the envelope of amplitude spectrum (hereinafter spectrum of the received signal. In this regard the laboratory model using eddy current metal detector will combat withdrawal from two samples – steel and copper, located along and calculate its range. The task of distinguishing between metal targets reduced to determining the hit spectra of reference samples obtained spectrum. The ratio between the areas is measured and reference spectra indicates the percentage of specific metals (e.g. two identical samples of different metals lying side by side. Signal processing is performed by specially designed program that compares two spectra along posted samples of black and colored metals with base.

NEW CONSTRAINTS ON A COMPLEX RELATION BETWEEN GLOBULAR CLUSTER COLORS AND ENVIRONMENT

Energy Technology Data Exchange (ETDEWEB)

Powalka, Mathieu; Lançon, Ariane [Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l’Université, F-67000 Strasbourg (France); Puzia, Thomas H.; Alamo-Martínez, Karla; Ángel, Simón [Institute of Astrophysics, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile); Peng, Eric W.; Lim, Sungsoon [Department of Astronomy, Peking University, Beijing 100871 (China); Schönebeck, Frederik; Grebel, Eva K. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstraße 12-14, D-69120 Heidelberg (Germany); Blakeslee, John P.; Côté, Patrick; Ferrarese, Laura; Gwyn, S. D. J. [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada); Cuillandre, Jean-Charles; Duc, Pierre-Alain [AIM Paris Saclay, CNRS/INSU, CEA/Irfu, Université Paris Diderot, Orme des Merisiers, F-91191 Gif-sur-Yvette Cedex (France); Durrell, Patrick [Department of Physics and Astronomy, Youngstown State University, One University Plaza, Youngstown, OH 44555 (United States); Guhathakurta, Puragra [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Kuntschner, Harald, E-mail: mathieu.powalka@astro.unistra.fr [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); and others

2016-09-20

We present an analysis of high-quality photometry for globular clusters (GCs) in the Virgo cluster core region, based on data from the Next Generation Virgo Cluster Survey (NGVS) pilot field, and in the Milky Way (MW), based on Very Large Telescope/X-Shooter spectrophotometry. We find significant discrepancies in color–color diagrams between sub-samples from different environments, confirming that the environment has a strong influence on the integrated colors of GCs. GC color distributions along a single color are not sufficient to capture the differences we observe in color–color space. While the average photometric colors become bluer with increasing radial distance to the cD galaxy M87, we also find a relation between the environment and the slope and intercept of the color–color relations. A denser environment seems to produce a larger dynamic range in certain color indices. We argue that these results are not due solely to differential extinction, Initial Mass Function variations, calibration uncertainties, or overall age/metallicity variations. We therefore suggest that the relation between the environment and GC colors is, at least in part, due to chemical abundance variations, which affect stellar spectra and stellar evolution tracks. Our results demonstrate that stellar population diagnostics derived from model predictions which are calibrated on one particular sample of GCs may not be appropriate for all extragalactic GCs. These results advocate a more complex model of the assembly history of GC systems in massive galaxies that goes beyond the simple bimodality found in previous decades.

NEW CONSTRAINTS ON A COMPLEX RELATION BETWEEN GLOBULAR CLUSTER COLORS AND ENVIRONMENT

International Nuclear Information System (INIS)

Powalka, Mathieu; Lançon, Ariane; Puzia, Thomas H.; Alamo-Martínez, Karla; Ángel, Simón; Peng, Eric W.; Lim, Sungsoon; Schönebeck, Frederik; Grebel, Eva K.; Blakeslee, John P.; Côté, Patrick; Ferrarese, Laura; Gwyn, S. D. J.; Cuillandre, Jean-Charles; Duc, Pierre-Alain; Durrell, Patrick; Guhathakurta, Puragra; Kuntschner, Harald

2016-01-01

We present an analysis of high-quality photometry for globular clusters (GCs) in the Virgo cluster core region, based on data from the Next Generation Virgo Cluster Survey (NGVS) pilot field, and in the Milky Way (MW), based on Very Large Telescope/X-Shooter spectrophotometry. We find significant discrepancies in color–color diagrams between sub-samples from different environments, confirming that the environment has a strong influence on the integrated colors of GCs. GC color distributions along a single color are not sufficient to capture the differences we observe in color–color space. While the average photometric colors become bluer with increasing radial distance to the cD galaxy M87, we also find a relation between the environment and the slope and intercept of the color–color relations. A denser environment seems to produce a larger dynamic range in certain color indices. We argue that these results are not due solely to differential extinction, Initial Mass Function variations, calibration uncertainties, or overall age/metallicity variations. We therefore suggest that the relation between the environment and GC colors is, at least in part, due to chemical abundance variations, which affect stellar spectra and stellar evolution tracks. Our results demonstrate that stellar population diagnostics derived from model predictions which are calibrated on one particular sample of GCs may not be appropriate for all extragalactic GCs. These results advocate a more complex model of the assembly history of GC systems in massive galaxies that goes beyond the simple bimodality found in previous decades.

Nonlinear transport theory in the metal with tunnel barrier

Science.gov (United States)

Zubov, E. E.

2018-02-01

Within the framework of the scattering matrix formalism, the nonlinear Kubo theory for electron transport in the metal with a tunnel barrier has been considered. A general expression for the mean electrical current was obtained. It significantly simplifies the calculation of nonlinear contributions to the conductivity of various hybrid structures. In the model of the tunnel Hamiltonian, all linear and nonlinear contributions to a mean electrical current are evaluated. The linear approximation agrees with results of other theories. For effective barrier transmission ?, the ballistic transport is realised with a value of the Landauer conductivity equal to ?.

Enhanced numerical analysis of three-color HgCdTe detectors

Science.gov (United States)

Jóźwikowski, K.; Rogalski, A.

2007-04-01

The performance of three-color HgCdTe photovoltaic heterostructure detector is examined theoretically. In comparison with two-color detectors with two back-to-back junctions, three-color structure contain an absorber of intermediate wavelength placed between two junctions, and electronic barriers are used to isolate this intermediate region. This structure was first proposed by British workers. Enhanced original computer programs are applied to solve the system of non-linear continuity equations for carriers and Poisson equations. In addition, the numerical analysis includes the dependence of absorption coefficient on Burstein effect as well as interference effects in heterostructure with metallic electrical contacts. Three detector structures with different localizations of separating barriers are analyzed. The calculations results are presented in the form of spatial distributions of bandgap energy and quantum efficiency. It is shown that the performance of the detector is critically dependent on the barrier's doping level and position in relation to the junction. This behavior is serious disadvantage of the considered three color detector. A small shift of the barrier location and doping level causes serious changes in spectral responsivity.

Phycoremediation of heavy metals by the three-color forms of Kappaphycus alvarezii

Energy Technology Data Exchange (ETDEWEB)

Suresh Kumar, K [Marine Algae and Marine Environment Discipline, Central Salt and Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavangar 364 002, Gujarat (India); Ganesan, K [Marine Algae and Marine Environment Discipline, Central Salt and Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavangar 364 002, Gujarat (India); Subba Rao, P V [Marine Algae and Marine Environment Discipline, Central Salt and Marine Chemicals Research Institute, Gijubhai Badheka Marg, Bhavangar 364 002, Gujarat (India)

2007-05-08

In the present investigation, three living color forms (brown, green and pale yellow) of Kappaphycus alvarezii were examined for their biosorption ability in the laboratory. The brown color form proved to be an excellent metal biosorbent, i.e. it could adsorb good amount of cadmium 3.064 mg/100 g f.wt. and cobalt 3.365 mg/100 g f.wt. It also removed 2.799 mg/100 g f.wt. of chromium. The green color form absorbed 2.684, 3.43 and 2.692 mg/100 g f.wt. of cadmium, cobalt and chromium, respectively. In contrast, the pale yellow form removed almost equal proportion of cadmium 0.961 mg/100 g f.wt. and chromium 0.942 mg/100 g f.wt. It also removed 1.403 mg/100 g f.wt. cobalt. Thus, the living color forms of this seaweed could form an effective biosorbent material for removal of heavy metals.

Phycoremediation of heavy metals by the three-color forms of Kappaphycus alvarezii

International Nuclear Information System (INIS)

Suresh Kumar, K.; Ganesan, K.; Subba Rao, P.V.

2007-01-01

In the present investigation, three living color forms (brown, green and pale yellow) of Kappaphycus alvarezii were examined for their biosorption ability in the laboratory. The brown color form proved to be an excellent metal biosorbent, i.e. it could adsorb good amount of cadmium 3.064 mg/100 g f.wt. and cobalt 3.365 mg/100 g f.wt. It also removed 2.799 mg/100 g f.wt. of chromium. The green color form absorbed 2.684, 3.43 and 2.692 mg/100 g f.wt. of cadmium, cobalt and chromium, respectively. In contrast, the pale yellow form removed almost equal proportion of cadmium 0.961 mg/100 g f.wt. and chromium 0.942 mg/100 g f.wt. It also removed 1.403 mg/100 g f.wt. cobalt. Thus, the living color forms of this seaweed could form an effective biosorbent material for removal of heavy metals

THE EFFECT OF SECOND-GENERATION POPULATIONS ON THE INTEGRATED COLORS OF METAL-RICH GLOBULAR CLUSTERS IN EARLY-TYPE GALAXIES

International Nuclear Information System (INIS)

Chung, Chul; Lee, Sang-Yoon; Yoon, Suk-Jin; Lee, Young-Wook

2013-01-01

The mean color of globular clusters (GCs) in early-type galaxies is in general bluer than the integrated color of halo field stars in host galaxies. Metal-rich GCs often appear more associated with field stars than metal-poor GCs, yet show bluer colors than their host galaxy light. Motivated by the discovery of multiple stellar populations in Milky Way GCs, we present a new scenario in which the presence of second-generation (SG) stars in GCs is responsible for the color discrepancy between metal-rich GCs and field stars. The model assumes that the SG populations have an enhanced helium abundance as evidenced by observations, and it gives a good explanation of the bluer optical colors of metal-rich GCs than field stars as well as strong Balmer lines and blue UV colors of metal-rich GCs. Ours may be complementary to the recent scenario suggesting the difference in stellar mass functions (MFs) as an origin for the GC-to-star color offset. A quantitative comparison is given between the SG and MF models.

Separation of irradiance and reflectance from observed color images by logarithmical nonlinear diffusion process

Science.gov (United States)

Saito, Takahiro; Takahashi, Hiromi; Komatsu, Takashi

2006-02-01

The Retinex theory was first proposed by Land, and deals with separation of irradiance from reflectance in an observed image. The separation problem is an ill-posed problem. Land and others proposed various Retinex separation algorithms. Recently, Kimmel and others proposed a variational framework that unifies the previous Retinex algorithms such as the Poisson-equation-type Retinex algorithms developed by Horn and others, and presented a Retinex separation algorithm with the time-evolution of a linear diffusion process. However, the Kimmel's separation algorithm cannot achieve physically rational separation, if true irradiance varies among color channels. To cope with this problem, we introduce a nonlinear diffusion process into the time-evolution. Moreover, as to its extension to color images, we present two approaches to treat color channels: the independent approach to treat each color channel separately and the collective approach to treat all color channels collectively. The latter approach outperforms the former. Furthermore, we apply our separation algorithm to a high quality chroma key in which before combining a foreground frame and a background frame into an output image a color of each pixel in the foreground frame are spatially adaptively corrected through transformation of the separated irradiance. Experiments demonstrate superiority of our separation algorithm over the Kimmel's separation algorithm.

Realization of diverse displays for multiple color patterns on metal surfaces

International Nuclear Information System (INIS)

Li, Guoqiang; Li, Jiawen; Hu, Yanlei; Zhang, Chenchu; Li, Xiaohong; Chu, Jiaru; Huang, Wenhao

2014-01-01

Highlights: • We have demonstrated that the combined influence of incident white light angle and the ripples orientation on the diversity of structural colors. • Our investigation revealed that multi-patterns constituted by ripples with different orientations could be precisely designed on metal surfaces. • The diverse display for the desired ones can be realized by exquisitely varying the incident light angle and rotating sample angle. - Abstract: Enhanced colors can be formed when white light is irradiated on the surface ripples induced by femtosecond laser. In this paper, we have demonstrated the ability to display the diverse colors by simultaneously adjusting the incident white light angle and the ripples orientation. Furthermore, our investigation revealed that multi-patterns constituted by ripples with different orientations could be designed on metal surfaces. The diverse display for the desired ones can be realized by exquisitely varying the incident light angle and rotating sample angle. More interestingly, it is found that, although the same patterns could be displayed under different conditions, the colors might be different. These findings can provide a novel method to carry and identify high quantity of information, which may find potential applications in the fields of information storage, identifying codes and anti-counterfeiting patterns

Third order nonlinear optical properties and optical limiting behavior of alkali metal complexes of p-nitrophenol

Science.gov (United States)

Thangaraj, M.; Vinitha, G.; Sabari Girisun, T. C.; Anandan, P.; Ravi, G.

2015-10-01

Optical nonlinearity of metal complexes of p-nitrophenolate (M=Li, Na and K) in ethanol is studied by using a continuous wave (cw) diode pumped Nd:YAG laser (532 nm, 50 mW). The predominant mechanism of observed nonlinearity is thermal in origin. The nonlinear refractive index and the nonlinear absorption coefficient of the samples were found to be in the order of 10-8 cm2/W and 10-3 cm/W respectively. Magnitude of third-order optical parameters varies according to the choice of alkali metal chosen for metal complex formation of p-nitrophenolate. The third-order nonlinear susceptibility was found to be in the order of 10-6 esu. The observed saturable absorption and the self-defocusing effect were used to demonstrate the optical limiting action at 532 nm by using the same cw laser beam.

Preliminary Test for Nonlinear Input Output Relations in SISO Systems

DEFF Research Database (Denmark)

Knudsen, Torben

2000-01-01

This paper discusses and develops preliminary statistical tests for detecting nonlinearities in the deterministic part of SISO systems with noise. The most referenced method is unreliable for common noise processes as e.g.\\ colored. Therefore two new methods based on superposition and sinus input...

Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach

Directory of Open Access Journals (Sweden)

Jiajie Fan

2017-07-01

Full Text Available With the expanding application of light-emitting diodes (LEDs, the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD, defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED’s optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1 the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2 the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs, and color rendering indexes (CRIs of phosphor-converted (pc-white LEDs, and also can estimate the residual color life.

Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach.

Science.gov (United States)

Fan, Jiajie; Mohamed, Moumouni Guero; Qian, Cheng; Fan, Xuejun; Zhang, Guoqi; Pecht, Michael

2017-07-18

With the expanding application of light-emitting diodes (LEDs), the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD), defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED's optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1) the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2) the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs), and color rendering indexes (CRIs) of phosphor-converted (pc)-white LEDs, and also can estimate the residual color life.

Nonlinear optical response of a gold surface in the visible range: A study by two-color sum-frequency generation spectroscopy. I. Experimental determination.

Science.gov (United States)

Dalstein, L; Revel, A; Humbert, C; Busson, B

2018-04-07

We experimentally determine the effective nonlinear second-order susceptibility of gold over the visible spectral range. To reach that goal, we probe by vibrational two-color sum-frequency generation spectroscopy the methyl stretching region of a dodecanethiol self-assembled monolayer adsorbed on a gold film. The sum-frequency generation spectra show a remarkable shape reversal when the visible probe wavelength is tuned from 435 to 705 nm. After correcting from Fresnel effects, the methyl stretching vibrations serve as an internal reference, allowing to extract the dispersion of the absolute phase and relative amplitude of the effective nonlinear optical response of gold in the visible range.

Feature-based attention is functionally distinct from relation-based attention: The double dissociation between color-based capture and color-relation-based capture of attention.

Science.gov (United States)

Du, Feng; Jiao, Jun

2016-04-01

The present study used a spatial blink task and a cuing task to examine the boundary between feature-based capture and relation-based capture. Feature-based capture occurs when distractors match the target feature such as target color. The occurrence of relation-based capture is contingent upon the feature relation between target and distractor (e.g., color relation). The results show that color distractors that match the target-nontarget color relation do not consistently capture attention when they appear outside of the attentional window, but distractors appearing outside the attentional window that match the target color consistently capture attention. In contrast, color distractors that best match the target-nontarget color relation but not the target color, are more likely to capture attention when they appear within the attentional window. Consistently, color cues that match the target-nontarget color relation produce a cuing effect when they appear within the attentional window, while target-color matched cues do not. Such a double dissociation between color-based capture and color-relation-based capture indicates functionally distinct mechanisms for these 2 types of attentional selection. This also indicates that the spatial blink task and the uninformative cuing task are measuring distinctive aspects of involuntary attention. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Phenomenological modeling of nonlinear holograms based on metallic geometric metasurfaces.

Science.gov (United States)

Ye, Weimin; Li, Xin; Liu, Juan; Zhang, Shuang

2016-10-31

Benefiting from efficient local phase and amplitude control at the subwavelength scale, metasurfaces offer a new platform for computer generated holography with high spatial resolution. Three-dimensional and high efficient holograms have been realized by metasurfaces constituted by subwavelength meta-atoms with spatially varying geometries or orientations. Metasurfaces have been recently extended to the nonlinear optical regime to generate holographic images in harmonic generation waves. Thus far, there has been no vector field simulation of nonlinear metasurface holograms because of the tremendous computational challenge in numerically calculating the collective nonlinear responses of the large number of different subwavelength meta-atoms in a hologram. Here, we propose a general phenomenological method to model nonlinear metasurface holograms based on the assumption that every meta-atom could be described by a localized nonlinear polarizability tensor. Applied to geometric nonlinear metasurfaces, we numerically model the holographic images formed by the second-harmonic waves of different spins. We show that, in contrast to the metasurface holograms operating in the linear optical regime, the wavelength of incident fundamental light should be slightly detuned from the fundamental resonant wavelength to optimize the efficiency and quality of nonlinear holographic images. The proposed modeling provides a general method to simulate nonlinear optical devices based on metallic metasurfaces.

Experimental observation of percolation-enhanced nonlinear light scattering from semicontinuous metal films

Science.gov (United States)

Breit, M.; Podolskiy, V. A.; Grésillon, S.; von Plessen, G.; Feldmann, J.; Rivoal, J. C.; Gadenne, P.; Sarychev, Andrey K.; Shalaev, Vladimir M.

2001-09-01

Strongly enhanced second-harmonic generation (SHG), which is characterized by a nearly isotropic intensity distribution, is observed for gold-glass films near the percolation threshold. The diffuselike SHG scattering, which can be thought of as nonlinear critical opalescence, is in sharp contrast with highly collimated linear reflection and transmission from these nanostructured semicontinuous metal films. Our observations, which can be explained by giant fluctuations of local nonlinear sources for SHG due to plasmon localization, verify recent predictions of percolation-enhanced nonlinear scattering.

Color gradients in elliptical galaxies

International Nuclear Information System (INIS)

Franx, M.; Illingworth, G.

1990-01-01

The relationship of the color gradients within ellipticals and the color differences between them are studied. It is found that the local color appears to be strongly related to the escape velocity. This suggests that the local escape velocity is the primary factor that determines the metallicity of the stellar population. Models with and without dark halos give comparable results. 27 refs

COLORS OF ELLIPTICALS FROM GALEX TO SPITZER

Energy Technology Data Exchange (ETDEWEB)

Schombert, James M., E-mail: jschombe@uoregon.edu [Department of Physics, University of Oregon, Eugene, OR 97403 (United States)

2016-12-01

Multi-color photometry is presented for a large sample of local ellipticals selected by morphology and isolation. The sample uses data from the Galaxy Evolution Explorer ( GALEX ), Sloan Digital Sky Survey (SDSS), Two Micron All-Sky Survey (2MASS), and Spitzer to cover the filters NUV , ugri , JHK and 3.6 μ m. Various two-color diagrams, using the half-light aperture defined in the 2MASS J filter, are very coherent from color to color, meaning that galaxies defined to be red in one color are always red in other colors. Comparison to globular cluster colors demonstrates that ellipticals are not composed of a single age, single metallicity (e.g., [Fe/H]) stellar population, but require a multi-metallicity model using a chemical enrichment scenario. Such a model is sufficient to explain two-color diagrams and the color–magnitude relations for all colors using only metallicity as a variable on a solely 12 Gyr stellar population with no evidence of stars younger than 10 Gyr. The [Fe/H] values that match galaxy colors range from −0.5 to +0.4, much higher (and older) than population characteristics deduced from Lick/IDS line-strength system studies, indicating an inconsistency between galaxy colors and line indices values for reasons unknown. The NUV colors have unusual behavior, signaling the rise and fall of the UV upturn with elliptical luminosity. Models with blue horizontal branch tracks can reproduce this behavior, indicating the UV upturn is strictly a metallicity effect.

COLORS OF ELLIPTICALS FROM GALEX TO SPITZER

International Nuclear Information System (INIS)

Schombert, James M.

2016-01-01

Multi-color photometry is presented for a large sample of local ellipticals selected by morphology and isolation. The sample uses data from the Galaxy Evolution Explorer ( GALEX ), Sloan Digital Sky Survey (SDSS), Two Micron All-Sky Survey (2MASS), and Spitzer to cover the filters NUV , ugri , JHK and 3.6 μ m. Various two-color diagrams, using the half-light aperture defined in the 2MASS J filter, are very coherent from color to color, meaning that galaxies defined to be red in one color are always red in other colors. Comparison to globular cluster colors demonstrates that ellipticals are not composed of a single age, single metallicity (e.g., [Fe/H]) stellar population, but require a multi-metallicity model using a chemical enrichment scenario. Such a model is sufficient to explain two-color diagrams and the color–magnitude relations for all colors using only metallicity as a variable on a solely 12 Gyr stellar population with no evidence of stars younger than 10 Gyr. The [Fe/H] values that match galaxy colors range from −0.5 to +0.4, much higher (and older) than population characteristics deduced from Lick/IDS line-strength system studies, indicating an inconsistency between galaxy colors and line indices values for reasons unknown. The NUV colors have unusual behavior, signaling the rise and fall of the UV upturn with elliptical luminosity. Models with blue horizontal branch tracks can reproduce this behavior, indicating the UV upturn is strictly a metallicity effect.

Color Memory: A Yang-Mills Analog of Gravitational Wave Memory

Science.gov (United States)

Pate, Monica; Raclariu, Ana-Maria; Strominger, Andrew

2017-12-01

A transient color flux across null infinity in classical Yang-Mills theory is considered. It is shown that a pair of test "quarks" initially in a color singlet generically acquire net color as a result of the flux. A nonlinear formula is derived for the relative color rotation of the quarks. For a weak color flux, the formula linearizes to the Fourier transform of the soft gluon theorem. This color memory effect is the Yang-Mills analog of the gravitational memory effect.

Effect of metal chloride solutions on coloration and biaxial flexural strength of yttria-stabilized zirconia

Science.gov (United States)

Oh, Gye-Jeong; Lee, Kwangmin; Lee, Doh-Jae; Lim, Hyun-Pil; Yun, Kwi-Dug; Ban, Jae-Sam; Lee, Kyung-Ku; Fisher, John G.; Park, Sang-Won

2012-10-01

The effect of three kinds of transition metal dopants on the color and biaxial flexural strength of zirconia ceramics for dental applications was evaluated. Presintered zirconia discs were colored through immersion in aqueous chromium, molybdenum and vanadium chloride solutions and then sintered at 1450 °C. The color of the doped specimens was measured using a digital spectrophotometer. For biaxial flexural strength measurements, specimens infiltrated with 0.3 wt% of each aqueous chloride solution were used. Uncolored discs were used as a control. Zirconia specimens infiltrated with chromium, molybdenum and vanadium chloride solutions were dark brown, light yellow and dark yellow, respectively. CIE L*, a*, and b* values of all the chromium-doped specimens and the specimens infiltrated with 0.1 wt% molybdenum chloride solution were in the range of values for natural teeth. The biaxial flexural strengths of the three kinds of metal chloride groups were similar to the uncolored group. These results suggest that chromium and molybdenum dopants can be used as colorants to fabricate tooth colored zirconia ceramic restorations.

Formation and properties of metallic nanoparticles in lithium and sodium fluorides with radiation-induced color centers

Science.gov (United States)

Bryukvina, L. I.; Martynovich, E. F.

2012-12-01

The specific features of light- and temperature-induced formation of metallic nanoparticles in γ-irradiated LiF and NaF crystals have been investigated. Atomic force microscope images of nanoparticles of different sizes and in different locations have been presented. The relation between the crystal processing regimes and properties of the nanoparticles formed has been revealed. The optical properties of the processed crystals have been analyzed. The thermo- and light-stimulated processes underlying the formation of metallic nanoparticles in aggregation of the color centers and their decay due to the recovery of the crystal lattice have been studied.

Volume fraction dependence of transient absorption signal and nonlinearities in metal nanocolloids

International Nuclear Information System (INIS)

Jayabalan, J; Singh, Asha; Khan, Salahuddin; Chari, Rama

2013-01-01

Electron–lattice thermalization dynamics in metal nanoparticles or in bulk metal is usually estimated by measuring the decay time of the change in transmission following an optical excitation. Such measurements can be performed in transient absorption geometry using a femtosecond laser. We find that for silver nanoplatelet/water colloids, the decay time of the transient absorption depends on the volume fraction of silver in water. By estimating the volume fraction dependence of nonlinearities in the same samples, we show that the variation in the measured decay time is due to pump-depletion effects present in the sample. The correct correction factor for taking into account pump-depletion effects in fifth- and higher-order nonlinearities is also presented. (paper)

Shear bond strength of metallic and ceramic brackets using color change adhesives.

Science.gov (United States)

Stumpf, Aisha de Souza Gomes; Bergmann, Carlos; Prietsch, José Renato; Vicenzi, Juliane

2013-01-01

To determine the shear bond strength of orthodontic brackets using color change adhesives that are supposed to aid in removing excess of bonding material and compare them to a traditional adhesive. Ninety metallic and ninety ceramic brackets were bonded to bovine incisors using two color change adhesives and a regular one. A tensile stress was applied by a universal testing machine. The teeth were observed in a microscope after debonding in order to determine the Adhesive Remnant Index (ARI). The statistical analysis (ANOVA, Tukey, and Kruskall-Wallis tests) demonstrated that the mean bond strength presented no difference when metallic and ceramic brackets were compared, but the bond resistance values were significantly different for the three adhesives used. The most common ARI outcome was the entire adhesive remaining on the enamel. The bond strength was similar for metallic and ceramic brackets when the same adhesive system was used. ARI scores demonstrated that bonding with these adhesives is safe even when ceramic brackets were used. On the other hand, bond strength was too low for orthodontic purposes when Ortho Lite Cure was used.

Effective-medium theory for nonlinear magneto-optics in magnetic granular alloys: cubic nonlinearity

International Nuclear Information System (INIS)

Granovsky, Alexander B.; Kuzmichov, Michail V.; Clerc, J.-P.; Inoue, Mitsuteru

2003-01-01

We propose a simple effective-medium approach for calculating the effective dielectric function of a magnetic metal-insulator granular alloy in which there is a weakly nonlinear relation between electric displacement D and electric field E for both constituent materials of the form D i =ε i (0) E i +χ i (3) |E i | 2 E i . We assume that linear ε i (0) and cubic nonlinear χ i (3) dielectric functions are diagonal and linear with magnetization non-diagonal components. For such metal-insulator composite magneto-optical effects depend on a light intensity and the effective cubic dielectric function χ eff (3) can be significantly greater (up to 10 3 times) than that for constituent materials. The calculation scheme is based on the Bergman and Stroud-Hui theory of nonlinear optical properties of granular matter. The giant cubic magneto-optical nonlinearity is found for composites with metallic volume fraction close to the percolation threshold and at a resonance of optical conductivity. It is shown that a composite may exhibit nonlinear magneto-optics even when both constituent materials have no cubic magneto-optical nonlinearity

Optical nonlinearities of excitonic states in atomically thin 2D transition metal dichalcogenides

Energy Technology Data Exchange (ETDEWEB)

Soh, Daniel Beom Soo [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Proliferation Signatures Discovery and Exploitation Department

2017-08-01

We calculated the optical nonlinearities of the atomically thin monolayer transition metal dichalcogenide material (particularly MoS₂), particularly for those linear and nonlinear transition processes that utilize the bound exciton states. We adopted the bound and the unbound exciton states as the basis for the Hilbert space, and derived all the dynamical density matrices that provides the induced current density, from which the nonlinear susceptibilities can be drawn order-by-order via perturbative calculations. We provide the nonlinear susceptibilities for the linear, the second-harmonic, the third-harmonic, and the kerr-type two-photon processes.

Color relations increase the capacity of visual short-term memory.

Science.gov (United States)

Sanocki, Thomas; Sulman, Noah

2011-01-01

Do color relations such as similarity or harmony influence the ease with which colored patterns can be perceived and held in mind? We tested the influence of a relation supported in research on color harmony--similarity of hue--on the capacity of visual short-term memory (VSTM) for colors in patterns. Palettes of 4 similar-hue colors were rated as more pleasant (harmonious) than dissimilar-color palettes. The palettes were used in a VSTM color task. Patterns of 9 to 15 colored squares were presented, and accuracy of color change detection was measured. Memory performance was higher overall for similar-color palettes than for dissimilar-color palettes (experiments 1 and 3). Is this due to color similarity per se, or due to the harmony between colors in similar palettes? A final experiment provided strong support for the importance of color similarity as opposed to harmony. Overall, the advantages for color similarity, in terms of number of color squares held in memory (memory capacity) were 26% to 45% over dissimilar colors. The results indicate that color relations can have a strong impact on the capacity for perceiving and retaining color patterns.

THEORETICAL CEPHEID PERIOD-LUMINOSITY AND PERIOD-COLOR RELATIONS IN SPITZER IRAC BANDS

International Nuclear Information System (INIS)

Ngeow, Chow-Choong; Marconi, Marcella; Musella, Ilaria; Cignoni, Michele; Kanbur, Shashsi M.

2012-01-01

In this paper, the synthetic period-luminosity (P-L) relations in Spitzer's IRAC bands, based on a series of theoretical pulsation models with varying metal and helium abundance, were investigated. Selected sets of these synthetic P-L relations were compared to the empirical IRAC band P-L relations recently determined from Galactic and Magellanic Clouds Cepheids. For the Galactic case, synthetic P-L relations from model sets with (Y = 0.26, Z = 0.01), (Y = 0.26, Z = 0.02), and (Y = 0.28, Z = 0.02) agree with the empirical Galactic P-L relations derived from the Hubble Space Telescope parallaxes. For Magellanic Cloud Cepheids, the synthetic P-L relations from model sets with (Y = 0.25, Z = 0.008) agree with both of the empirical Large Magellanic Cloud (LMC) and Small Magellanic Cloud P-L relations. Analysis of the synthetic P-L relations from all model sets suggested that the IRAC band P-L relations may not be independent of metallicity, as the P-L slopes and intercepts could be affected by the metallicity and/or helium abundance. We also derive the synthetic period-color (P-C) relations in the IRAC bands. Non-vanishing synthetic P-C relations were found for certain combinations of IRAC band filters and metallicity. However, the synthetic P-C relations disagreed with the [3.6]-[8.0] P-C relation recently found for the Galactic Cepheids. The synthetic [3.6]-[4.5] P-C slope from the (Y = 0.25, Z = 0.008) model set, on the other hand, is in excellent agreement to the empirical LMC P-C counterpart, if a period range 1.0 < log (P) < 1.8 is adopted.

Mesomorphic glass nanocomposites made of metal alkanoates and nanoparticles as emerging nonlinear-optical materials

Science.gov (United States)

Garbovskiy, Y.; Klimusheva, G.; Mirnaya, T.

2016-09-01

Mesomorphic metal alkanoates is very promising yet overlooked class of nonlinear-optical materials. Metal alkanoates can exhibit a broad variety of condensed states of matter including solid crystals, plastic crystals, lyotropic and thermotropic ionic liquid crystals, liquids, mesomorphic glasses, and Langmuir-Blodgett films. Glass-forming properties of metal alkanoates combined with their use as nano-reactors and anisotropic host open up simple and efficient way to design various photonic nanomaterials. Despite very interesting physics, the experimental data on optical and nonlinearoptical properties of such materials are scarce. The goal of the present paper is to fill the gap by discussing recent advances in the field of photonic materials made of metal alkanoates, organic dyes, and nanoparticles. Optical and nonlinear-optical properties of the following materials are reviewed: (i) mesomorphic glass doped with organic dyes; (ii) smectic glass composed of cobalt alkanoates; (iii) semiconductor nanoparticles embedded in a glassy host; (iv) metal nanoparticles - glass (the cobalt octanoate) nanocomposites.

Nonlinear optical spectroscopy of isotropic and anisotropic metallic nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Hernandez, R C; Gleason-Villagran, R; Cheang-Wong, J C; Crespo-Sosa, A; Rodriguez-Fernandez, L; Lopez-Suarez, A; Oliver, A; Reyes-Esqueda, J A [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Mexico, D. F. 04510 (Mexico); Torres-Torres, C [Seccion de Estudios de Posgrado e Investigacion, ESIME-Zacatenco, Instituto Politecnico Nacional, Mexico, D. F. 07338 (Mexico); Rangel-Rojo, R, E-mail: reyes@fisica.unam.mx [CICESE/Depto. de Optica, A.P. 360, Ensenada, B. C. 22860 (Mexico)

2011-01-01

In this work, we studied the nonlinear absorption and refraction of isotropic and anisotropic metallic nanocomposites, which consist of Au and Ag nanoparticles (NPs) embedded in matrices of SiO{sub 2}. We performed this study at different wavelengths using the Z-scan technique in the picosecond regime. The wavelengths were selected accordingly to the absorption spectra of the nanocomposites, choosing wavelengths into the inter- and intra-band transitions regions, including the surface plasmon (SP) resonance, as well as in the transparent region. For the anisotropic nanocomposites, the polarization and the incident angle were varied in order to evaluate the different components of the third order susceptibility tensor, {chi}{sup (3)}. We observed dramatic changes of sign for both, nonlinear refraction and absorption, when passing from Au to Ag and/or varying the wave length. The results accentuate the importance of the hot-electrons contribution to the nonlinear optical response at this temporal regime, when compared to inter-band and intra-band transitions contributions.

Nonlinear optical spectroscopy of isotropic and anisotropic metallic nanocomposites

International Nuclear Information System (INIS)

Fernandez-Hernandez, R C; Gleason-Villagran, R; Cheang-Wong, J C; Crespo-Sosa, A; Rodriguez-Fernandez, L; Lopez-Suarez, A; Oliver, A; Reyes-Esqueda, J A; Torres-Torres, C; Rangel-Rojo, R

2011-01-01

In this work, we studied the nonlinear absorption and refraction of isotropic and anisotropic metallic nanocomposites, which consist of Au and Ag nanoparticles (NPs) embedded in matrices of SiO 2 . We performed this study at different wavelengths using the Z-scan technique in the picosecond regime. The wavelengths were selected accordingly to the absorption spectra of the nanocomposites, choosing wavelengths into the inter- and intra-band transitions regions, including the surface plasmon (SP) resonance, as well as in the transparent region. For the anisotropic nanocomposites, the polarization and the incident angle were varied in order to evaluate the different components of the third order susceptibility tensor, χ (3) . We observed dramatic changes of sign for both, nonlinear refraction and absorption, when passing from Au to Ag and/or varying the wave length. The results accentuate the importance of the hot-electrons contribution to the nonlinear optical response at this temporal regime, when compared to inter-band and intra-band transitions contributions.

Integrated color face graphs for plant accident display

International Nuclear Information System (INIS)

Hara, Fumio

1987-01-01

This paper presents an integrated man-machine interface that uses cartoon-like colored graphs in the form of faces, that, through different facial expressions, display a plant condition. This is done by drawing the face on a CRT by nonlinearly transforming 31 variables and coloring the face. This integrated color graphics technique is applied to display the progess of events in the Three Mile Island nuclear power plant accident. Human visual perceptive characteristics are investigated in relation to the perception of the plant accident process, the naturality in face color change, and the consistency between facial expressions and colors. This paper concludes that colors used in an integrated color face graphs must be completely consistent with emotional feelings perceived from the colors. (author)

Relation of deformed nonlinear algebras with linear ones

International Nuclear Information System (INIS)

Nowicki, A; Tkachuk, V M

2014-01-01

The relation between nonlinear algebras and linear ones is established. For a one-dimensional nonlinear deformed Heisenberg algebra with two operators we find the function of deformation for which this nonlinear algebra can be transformed to a linear one with three operators. We also establish the relation between the Lie algebra of total angular momentum and corresponding nonlinear one. This relation gives a possibility to simplify and to solve the eigenvalue problem for the Hamiltonian in a nonlinear case using the reduction of this problem to the case of linear algebra. It is demonstrated in an example of a harmonic oscillator. (paper)

Shear bond strength of metallic and ceramic brackets using color change adhesives

Directory of Open Access Journals (Sweden)

Aisha de Souza Gomes Stumpf

2013-04-01

Full Text Available OBJECTIVE: To determine the shear bond strength of orthodontic brackets using color change adhesives that are supposed to aid in removing excess of bonding material and compare them to a traditional adhesive. METHODS: Ninety metallic and ninety ceramic brackets were bonded to bovine incisors using two color change adhesives and a regular one. A tensile stress was applied by a universal testing machine. The teeth were observed in a microscope after debonding in order to determine the Adhesive Remnant Index (ARI. RESULTS: The statistical analysis (ANOVA, Tukey, and Kruskall-Wallis tests demonstrated that the mean bond strength presented no difference when metallic and ceramic brackets were compared but the bond resistance values were significantly different for the three adhesives used. The most common ARI outcome was the entire adhesive remaining on the enamel. CONCLUSIONS: The bond strength was similar for metallic and ceramic brackets when the same adhesive system was used. ARI scores demonstrated that bonding with these adhesives is safe even when ceramic brackets were used. On the other hand, bond strength was too low for orthodontic purposes when Ortho Lite Cure was used.

Effective-medium theory for nonlinear magneto-optics in magnetic granular alloys: cubic nonlinearity

Energy Technology Data Exchange (ETDEWEB)

Granovsky, Alexander B. E-mail: granov@magn.ru; Kuzmichov, Michail V.; Clerc, J.-P.; Inoue, Mitsuteru

2003-03-01

We propose a simple effective-medium approach for calculating the effective dielectric function of a magnetic metal-insulator granular alloy in which there is a weakly nonlinear relation between electric displacement D and electric field E for both constituent materials of the form D{sub i}={epsilon}{sub i}{sup (0)}E{sub i} +{chi}{sub i}{sup (3)}|E{sub i}|{sup 2}E{sub i}. We assume that linear {epsilon}{sub i}{sup (0)} and cubic nonlinear {chi}{sub i}{sup (3)} dielectric functions are diagonal and linear with magnetization non-diagonal components. For such metal-insulator composite magneto-optical effects depend on a light intensity and the effective cubic dielectric function {chi}{sub eff}{sup (3)} can be significantly greater (up to 10{sup 3} times) than that for constituent materials. The calculation scheme is based on the Bergman and Stroud-Hui theory of nonlinear optical properties of granular matter. The giant cubic magneto-optical nonlinearity is found for composites with metallic volume fraction close to the percolation threshold and at a resonance of optical conductivity. It is shown that a composite may exhibit nonlinear magneto-optics even when both constituent materials have no cubic magneto-optical nonlinearity.

THEORETICAL CEPHEID PERIOD-LUMINOSITY AND PERIOD-COLOR RELATIONS IN SPITZER IRAC BANDS

Energy Technology Data Exchange (ETDEWEB)

Ngeow, Chow-Choong [Graduate Institute of Astronomy, National Central University, Jhongli City 32001, Taiwan (China); Marconi, Marcella; Musella, Ilaria [Osservatorio Astronomico di Capodimonte, Via Moiariello 16, 80131 Napoli (Italy); Cignoni, Michele [Department of Astronomy, Bologna University, via Ranzani 1, 40127 Bologna (Italy); Kanbur, Shashsi M. [Department of Physics, State University of New York at Oswego, Oswego, NY 13126 (United States)

2012-02-01

In this paper, the synthetic period-luminosity (P-L) relations in Spitzer's IRAC bands, based on a series of theoretical pulsation models with varying metal and helium abundance, were investigated. Selected sets of these synthetic P-L relations were compared to the empirical IRAC band P-L relations recently determined from Galactic and Magellanic Clouds Cepheids. For the Galactic case, synthetic P-L relations from model sets with (Y = 0.26, Z = 0.01), (Y = 0.26, Z = 0.02), and (Y = 0.28, Z = 0.02) agree with the empirical Galactic P-L relations derived from the Hubble Space Telescope parallaxes. For Magellanic Cloud Cepheids, the synthetic P-L relations from model sets with (Y = 0.25, Z = 0.008) agree with both of the empirical Large Magellanic Cloud (LMC) and Small Magellanic Cloud P-L relations. Analysis of the synthetic P-L relations from all model sets suggested that the IRAC band P-L relations may not be independent of metallicity, as the P-L slopes and intercepts could be affected by the metallicity and/or helium abundance. We also derive the synthetic period-color (P-C) relations in the IRAC bands. Non-vanishing synthetic P-C relations were found for certain combinations of IRAC band filters and metallicity. However, the synthetic P-C relations disagreed with the [3.6]-[8.0] P-C relation recently found for the Galactic Cepheids. The synthetic [3.6]-[4.5] P-C slope from the (Y = 0.25, Z = 0.008) model set, on the other hand, is in excellent agreement to the empirical LMC P-C counterpart, if a period range 1.0 < log (P) < 1.8 is adopted.

Localized surface plasmons modulated nonlinear optical processes in metal film-coupled and upconversion nanocrystals-coated nanoparticles (Conference Presentation)

Science.gov (United States)

Lei, Dangyuan

2016-09-01

In the first part of this talk, I will show our experimental investigation on the linear and nonlinear optical properties of metal film-coupled nanosphere monomers and dimers both with nanometric gaps. We have developed a new methodology - polarization resolved spectral decomposition and color decoding to "visualizing" unambiguously the spectral and radiation properties of the complex plasmonic gap modes in these hybrid nanostructures. Single-particle spectroscopic measurements indicate that these hybrid nanostructures can simultaneously enhance several nonlinear optical processes, such as second harmonic generation, two-photon absorption induced luminescence, and hyper-Raman scattering. In the second part, I will show how the polarization state of the emissions from sub-10 nm upconversion nanocrystals (UCNCs) can be modulated when they form a hybrid complex with a gold nanorod (GNR). Our single-particle scattering experiments expose how an interplay between excitation polarization and GNR orientation gives rise to an extraordinary polarized nature of the upconversion emissions from an individual hybrid nanostructure. We support our results by numerical simulations and, using Förster resonance energy transfer theory, we uncover how an overlap between the UCNC emission and GNR extinction bands as well as the mutual orientation between emission and plasmonic dipoles jointly determine the polarization state of the UC emissions.

Nonlinear dynamics of trions under strong optical excitation in monolayer MoSe2.

Science.gov (United States)

Ye, Jialiang; Yan, Tengfei; Niu, Binghui; Li, Ying; Zhang, Xinhui

2018-02-05

By employing ultrafast transient reflection measurements based on two-color pump-probe spectroscopy, the population and valley polarization dynamics of trions in monolayer MoSe 2 were investigated at relatively high excitation densities under near-resonant excitation. Both the nonlinear dynamic photobleaching of the trion resonance and the redshift of the exciton resonance were found to be responsible for the excitation-energy- and density-dependent transient reflection change as a result of many-body interactions. Furthermore, from the polarization-resolved measurements, it was revealed that the initial fast population and polarization decay process upon strong photoexcitation observed for trions was determined by trion formation, transient phase-space filling and the short valley lifetime of excitons. The results provide a basic understanding of the nonlinear dynamics of population and valley depolarization of trions, as well as exciton-trion correlation in atomically thin MoSe 2 and other transition metal dichalcogenide materials.

Towards representation of a perceptual color manifold using associative memory for color constancy.

Science.gov (United States)

Seow, Ming-Jung; Asari, Vijayan K

2009-01-01

In this paper, we propose the concept of a manifold of color perception through empirical observation that the center-surround properties of images in a perceptually similar environment define a manifold in the high dimensional space. Such a manifold representation can be learned using a novel recurrent neural network based learning algorithm. Unlike the conventional recurrent neural network model in which the memory is stored in an attractive fixed point at discrete locations in the state space, the dynamics of the proposed learning algorithm represent memory as a nonlinear line of attraction. The region of convergence around the nonlinear line is defined by the statistical characteristics of the training data. This learned manifold can then be used as a basis for color correction of the images having different color perception to the learned color perception. Experimental results show that the proposed recurrent neural network learning algorithm is capable of color balance the lighting variations in images captured in different environments successfully.

Test for Nonlinear Input Output Relations in SISO Systems by Preliminary Data Analysis

DEFF Research Database (Denmark)

Knudsen, Torben

2000-01-01

This paper discusses and develops preliminary statistical tests for detecting nonlinearities in the deterministic part of SISO systems with noise. The most referenced method is unreliable for common noise processes as e.g.\\ colored. Therefore two new methods based on superposition and sinus input...

Photon-pair generation in nonlinear metal-dielectric one-dimensional photonic structures

Czech Academy of Sciences Publication Activity Database

Javůrek, D.; Svozilík, J.; Peřina ml., Jan

2014-01-01

Roč. 90, č. 5 (2014), "053813-1"-"053813-14" ISSN 1050-2947 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : photon pairs * nonlinear metal-dielectric * one-dimensional photonic structures Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.808, year: 2014

Structural control of nonlinear optical absorption and refraction in dense metal nanoparticle arrays.

Science.gov (United States)

Kohlgraf-Owens, Dana C; Kik, Pieter G

2009-08-17

The linear and nonlinear optical properties of a composite containing interacting spherical silver nanoparticles embedded in a dielectric host are studied as a function of interparticle separation using three dimensional frequency domain simulations. It is shown that for a fixed amount of metal, the effective third-order nonlinear susceptibility of the composite chi((3))(omega) can be significantly enhanced with respect to the linear optical properties, due to a combination of resonant surface plasmon excitation and local field redistribution. It is shown that this geometry-dependent susceptibility enhancement can lead to an improved figure of merit for nonlinear absorption. Enhancement factors for the nonlinear susceptibility of the composite are calculated, and the complex nature of the enhancement factors is discussed.

Relative speed of processing determines color-word contingency learning.

Science.gov (United States)

Forrin, Noah D; MacLeod, Colin M

2017-10-01

In three experiments, we tested a relative-speed-of-processing account of color-word contingency learning, a phenomenon in which color identification responses to high-contingency stimuli (words that appear most often in particular colors) are faster than those to low-contingency stimuli. Experiment 1 showed equally large contingency-learning effects whether responding was to the colors or to the words, likely due to slow responding to both dimensions because of the unfamiliar mapping required by the key press responses. For Experiment 2, participants switched to vocal responding, in which reading words is considerably faster than naming colors, and we obtained a contingency-learning effect only for color naming, the slower dimension. In Experiment 3, previewing the color information resulted in a reduced contingency-learning effect for color naming, but it enhanced the contingency-learning effect for word reading. These results are all consistent with contingency learning influencing performance only when the nominally irrelevant feature is faster to process than the relevant feature, and therefore are entirely in accord with a relative-speed-of-processing explanation.

On The Generation of Interferometric Colors in High Purity and Technical Grade Aluminum: An Alternative Green Process for Metal Finishing Industry

International Nuclear Information System (INIS)

Chen, Yuting; Santos, Abel; Ho, Daena; Wang, Ye; Kumeria, Tushar; Li, Junsheng; Wang, Changhai; Losic, Dusan

2015-01-01

Graphical abstract: Toward green processes in metal finishing industry by rationally designed electrochemical anodization. Biomimetic photonic films based on nanoporous anodic alumina produced in high purity and technical grade aluminum foils display vivid colors that can be precisely tuned across the visible spectrum. The presented method is a solid rationale aimed toward green processes for metal finishing industry. - Highlights: • Environmentally friendly approach to color aluminum through biomimetic photonic films. • Nanoporous anodic alumina distributed Bragg Reflectors (NAA-DBRs). • Rationally designed galvanostatic pulse anodization approach. • Macroscopic and microscopic differences in high purity and technical grade aluminum. • Substitute method for conventional coloring processes in metal finishing industry. - Abstract: Metal finishing industry is one of the leading pollutants worldwide and green approaches are urgently needed in order to address health and environmental issues associated with this industrial activity. Herein, we present an environmentally friendly approach aimed to overcome some of these issues by coloring aluminum through biomimetic photonic films based on nanoporous anodic alumina distributed Bragg Reflectors (NAA-DBRs). Our study aims to compare the macroscopic and microscopic differences between the resulting photonic films produced in high purity and technical grade aluminum in terms of color features, appearance, electrochemical behavior and internal nanoporous structure in order to establish a solid rationale toward optimal fabrication processes that can be readily incorporated into industrial methodologies. The obtained results reveal that our approach, based on a rational galvanostatic pulse anodization approach, makes it possible to precisely generate a complete palette of colors in both types of aluminum substrates. As a result of its versatility, this method could become a promising alternative to substitute

Effects of hydroxycinnamic acids on blue color expression of cyanidin derivatives and their metal chelates.

Science.gov (United States)

Sigurdson, G T; Robbins, R J; Collins, T M; Giusti, M M

2017-11-01

Mechanisms to recreate many anthocyanin blue hues in nature are not fully understood, but interactions with metal ions and phenolic compounds are thought to play important roles. Bluing effects of hydroxycinnamic acids on cyanidin and chelates were investigated by addition of the acids to triglycosylated cyanidin (0-50×[anthocyanin]) and by comparison to hydroxycinnamic acid monoacylated and diacylated Cy fractions by spectrophotometry (380-700nm) and colorimetry in pH 5-8. With no metal ions, λ max and absorbance was greatest for cyanidin with diacylation>monoacylation>increasing [acids]. Hydroxycinnamic acids added to cyanidin solutions weakly impacted color characteristics (ΔEacid attachment) resulted in ΔE 5-15. Triglycosylated cyanidin expressed blue color (pH 7-8), suggesting glycosylation pattern also plays a role. Al 3+ chelation increased absorbance 2-42× and λ max ≳40nm (pH 5-6) compared to added hydroxycinnamic acids. Metal chelation and aromatic diacylation resulted in the most blue hues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetodynamic non-linearity of electric properties of uncompensated metals

International Nuclear Information System (INIS)

Sobol', V.R.; Mazurenko, O.N.

2001-01-01

Magnetodynamic non-linearity of electric properties of normal metals is investigated both experimentally and analytically provided that the drift of charge carriers of high density in crossed electric and magnetic fields results in generation of a self current field. The measurements were made on high purity polycrystalline aluminium cylindrical conductors under the action of the magnetic field, coaxial the sample axis, on the radial current. The electric potential and its nonlinear correction are determined in a wide range of energy dissipation values up to the levels corresponding to the crisis of liquid helium boiling. In the approximation of contribution additivity to the resistive effect of both the external and self magnetic field agreement between the experimental data and the results calculated using the macroscopic field equations is attained. The problems of magnetic energy concentration for cylindrical conductors is discussed in the approximation of long and short solenoids

Color-magnitude relations in nearby galaxy clusters

Science.gov (United States)

Rasheed, Mariwan A.; Mohammad, Khalid K.

2018-06-01

The rest-frame (g-r) /Mr color-magnitude relations of 12 Abell-type clusters are analyzed in the redshift range (0.02≲ z ≲ 0.10) and within a projected radius of 0.75 Mpc using photometric data from SDSS-DR9. We show that the color-magnitude relation parameters (slope, zero-point, and scatter) do not exhibit significant evolution within this low-redshift range. Thus, we can say that during the look-back time of z ˜ 0.1 all red sequence galaxies evolve passively, without any star formation activity.

Working Memory Is Related to Perceptual Processing: A Case from Color Perception

Science.gov (United States)

Allen, Elizabeth C.; Beilock, Sian L.; Shevell, Steven K.

2011-01-01

We explored the relation between individual differences in working memory (WM) and color constancy, the phenomenon of color perception that allows us to perceive the color of an object as relatively stable under changes in illumination. Successive color constancy (measured by first viewing a colored surface under a particular illumination and…

Nonlinear generalization of special relativity

International Nuclear Information System (INIS)

Winterberg, F.

1985-01-01

In Poincares axiomatic formulation special relativity is a derived consequence of a true Lorentz contraction, for a rod in absolute motion through a substratum. Furthermore, Lorentz had shown that the rod contraction can be understood by an inverse square law interaction and therefore special relativity derived from more fundamental principles. The derivation by Lorentz shows that the root of the divergence problems is the singular inverse square law. By replacing the inverse square law with a regular one through the introduction of a finite length, the author has succeeded in deriving a nonlinear generalization of special relativity which eliminates all infinities. Besides the relative velocities, these nonlinear transformation equations also contain absolute velocities against a substratum, but in the limit of small energies they go over into the linear Lorentz transformations. Depending on the smallness of the fundamental length, departures from special relativity can be observed only at very high energies. The theorem that the velocity of light is the same in all reference systems still holds and likewise the conservation laws for energy and momentum

Color confinement and a superconvergence relation

International Nuclear Information System (INIS)

Nishijima, Kazuhiko

1987-01-01

The spectral function of the transverse gluon propagator satisfies a superconvergence relation when the number of generations does not exceed four. This relation is shown to be connected with various interpretations of color confinement, such as metric cancellation, the bag model and the area law in lattice QCD. (author)

Color-size Relations of Disc Galaxies with Similar Stellar Masses

Science.gov (United States)

Fu, W.; Chang, R. X.; Shen, S. Y.; Zhang, B.

2011-01-01

To investigate the correlations between colors and sizes of disc galaxies with similar stellar masses, a sample of 7959 local face-on disc galaxies is collected from the main galaxy sample of the Seventh Data Release of Sloan Digital Sky Survey (SDSS DR7). Our results show that, under the condition that the stellar masses of disc galaxies are similar, the relation between u-r and size is weak, while g-r, r-i and r-z colors decrease with disk size. This means that the color-size relations of disc galaxies with similar stellar masses do exist, i.e., the more extended disc galaxies with similar stellar masses tend to have bluer colors. An artificial sample is constructed to confirm that this correlation is not driven by the color-stellar mass relations and size-stellar mass relation of disc galaxies. Our results suggest that the mass distribution of disk galaxies may have an important influence on their stellar formation history, i.e., the galaxies with more extended mass distribution evolve more slowly.

Feature-based automatic color calibration for networked camera system

Science.gov (United States)

Yamamoto, Shoji; Taki, Keisuke; Tsumura, Norimichi; Nakaguchi, Toshiya; Miyake, Yoichi

2011-01-01

In this paper, we have developed a feature-based automatic color calibration by using an area-based detection and adaptive nonlinear regression method. Simple color matching of chartless is achieved by using the characteristic of overlapping image area with each camera. Accurate detection of common object is achieved by the area-based detection that combines MSER with SIFT. Adaptive color calibration by using the color of detected object is calculated by nonlinear regression method. This method can indicate the contribution of object's color for color calibration, and automatic selection notification for user is performed by this function. Experimental result show that the accuracy of the calibration improves gradually. It is clear that this method can endure practical use of multi-camera color calibration if an enough sample is obtained.

Nonlinear constitutive relations for anisotropic elastic materials

Science.gov (United States)

Sokolova, Marina; Khristich, Dmitrii

2018-03-01

A general approach to constructing of nonlinear variants of connection between stresses and strains in anisotropic materials with different types of symmetry of properties is considered. This approach is based on the concept of elastic proper subspaces of anisotropic materials introduced in the mechanics of solids by J. Rychlewski and on the particular postulate of isotropy proposed by A. A. Il’yushin. The generalization of the particular postulate on the case of nonlinear anisotropic materials is formulated. Systems of invariants of deformations as lengths of projections of the strain vector into proper subspaces are developed. Some variants of nonlinear constitutive relations for anisotropic materials are offered. The analysis of these relations from the point of view of their satisfaction to general and limit forms of generalization of partial isotropy postulate on anisotropic materials is performed. The relations for particular cases of anisotropy are written.

Nonlinear optics at interfaces

International Nuclear Information System (INIS)

Chen, C.K.

1980-12-01

Two aspects of surface nonlinear optics are explored in this thesis. The first part is a theoretical and experimental study of nonlinear intraction of surface plasmons and bulk photons at metal-dielectric interfaces. The second part is a demonstration and study of surface enhanced second harmonic generation at rough metal surfaces. A general formulation for nonlinear interaction of surface plasmons at metal-dielectric interfaces is presented and applied to both second and third order nonlinear processes. Experimental results for coherent second and third harmonic generation by surface plasmons and surface coherent antiStokes Raman spectroscopy (CARS) are shown to be in good agreement with the theory

Fabrication of Metallic Quantum Dot Arrays For Nanoscale Nonlinear Optics

Science.gov (United States)

McMahon, M. D.; Hmelo, A. B.; Lopez Magruder, R., III; Weller Haglund, R. A., Jr.; Feldman, L. C.

2003-03-01

Ordered arrays of metal nanocrystals embedded in or sequestered on dielectric hosts have potential applications as elements of nonlinear or near-field optical circuits, as sensitizers for fluorescence emitters and photo detectors, and as anchor points for arrays of biological molecules. Metal nanocrystals are strongly confined electronic systems with size-, shape and spatial orientation-dependent optical responses. At the smallest scales (below about 15 nm diameter), their band structure is drastically altered by the small size of the system, and the reduced population of conduction-band electrons. Here we report on the fabrication of two-dimensional ordered metallic nanocrystal arrays, and one-dimensional nanocrystal-loaded waveguides for optical investigations. We have employed strategies for synthesizing metal nanocrystal composites that capitalize on the best features of focused ion beam (FIB) machining and pulsed laser deposition (PLD). The FIB generates arrays of specialized sites; PLD vapor deposition results in the directed self-assembly of Ag nanoparticles nucleated at the FIB generated sites on silicon substrates. We present results based on the SEM, AFM and optical characterization of prototype composites. This research has been supported by the U.S. Department of Energy under grant DE-FG02-01ER45916.

[Comparison of color reappearance between metal-ceram restoration and foundry-ceram restoration using crystaleye spectrophotometer].

Science.gov (United States)

Shi, Tao; Zhang, Ning; Kong, Fan-wen; Zhan, De-song

2010-10-01

To study the color reappearance effect of metal-ceram restoration and foundry-ceram restoration using Crystaleye spectrophotometer. 58 metal-ceram restorations and 58 foundry-ceram restorations according to the result of the Crystaleye spectrophotometer were made respectively. The deltaE between restorations and natural teeth as referenced were analyzed. And satisfaction of dentists and patients were evaluated. The deltaE between metal-ceram restorations and natural teeth was 7.13 +/- 0.74. The deltaE between foundry-ceram restorations and teeth was 1.47 +/- 0.84. There were statistical differences between the deltaE (P spectrophotometer can provide accurate reference for foundry-ceram restoration, but for metal-ceram restoration it is not accurate.

Individual differences in simultaneous color constancy are related to working memory.

Science.gov (United States)

Allen, Elizabeth C; Beilock, Sian L; Shevell, Steven K

2012-02-01

Few studies have investigated the possible role of higher-level cognitive mechanisms in color constancy. Following up on previous work with successive color constancy [J. Exper. Psychol. Learn. Mem. Cogn. 37, 1014 (2011)], the current study examined the relation between simultaneous color constancy and working memory-the ability to maintain a desired representation while suppressing irrelevant information. Higher working memory was associated with poorer simultaneous color constancy of a chromatically complex stimulus. Ways in which the executive attention mechanism of working memory may account for this are discussed. This finding supports a role for higher-level cognitive mechanisms in color constancy and is the first to demonstrate a relation between simultaneous color constancy and a complex cognitive ability. © 2012 Optical Society of America

ABOUT THE LINEARITY OF THE COLOR-MAGNITUDE RELATION OF EARLY-TYPE GALAXIES IN THE VIRGO CLUSTER

Energy Technology Data Exchange (ETDEWEB)

Smith Castelli, Analia V.; Faifer, Favio R. [Instituto de Astrofisica de La Plata (CCT-La Plata, CONICET-UNLP), Paseo del Bosque s/n, B1900FWA, La Plata (Argentina); Gonzalez, Nelida M. [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, La Plata, B1900FWA (Argentina); Forte, Juan Carlos, E-mail: asmith@fcaglp.unlp.edu.ar, E-mail: ngonzalez@fcaglp.unlp.edu.ar, E-mail: favio@fcaglp.unlp.edu.ar, E-mail: forte@fcaglp.unlp.edu.ar [CONICET-Planetario de la Ciudad de Buenos Aires ' ' Galileo Galilei' ' , Av. Sarmiento y B. Roldan, Ciudad Autonoma de Buenos Aires (Argentina)

2013-07-20

We revisit the color-magnitude relation of Virgo Cluster early-type galaxies in order to explore its alleged nonlinearity. To this aim, we reanalyze the relation already published from data obtained within the ACS Virgo Cluster Survey of the Hubble Space Telescope and perform our own photometry and analysis of the images of 100 early-type galaxies observed as part of this survey. In addition, we compare our results with those reported in the literature from data of the Sloan Digital Sky Survey. We have found that when the brightest galaxies and untypical systems are excluded from the sample, a linear relation arises in agreement with what is observed in other groups and clusters. The central regions of the brightest galaxies also follow this relation. In addition, we notice that Virgo contains at least four compact elliptical galaxies besides the well-known object VCC 1297 (NGC 4486B). Their locations in the ({mu}{sub eff})-luminosity diagram define a trend different from that followed by normal early-type dwarf galaxies, setting an upper limit in effective surface brightness and a lower limit in the effective radius for their luminosities. Based on the distribution of different galaxy sub-samples in the color-magnitude and ({mu}{sub eff})-luminosity diagrams, we draw some conclusions on their formation and the history of their evolution.

ABOUT THE LINEARITY OF THE COLOR-MAGNITUDE RELATION OF EARLY-TYPE GALAXIES IN THE VIRGO CLUSTER

International Nuclear Information System (INIS)

Smith Castelli, Analía V.; Faifer, Favio R.; González, Nélida M.; Forte, Juan Carlos

2013-01-01

We revisit the color-magnitude relation of Virgo Cluster early-type galaxies in order to explore its alleged nonlinearity. To this aim, we reanalyze the relation already published from data obtained within the ACS Virgo Cluster Survey of the Hubble Space Telescope and perform our own photometry and analysis of the images of 100 early-type galaxies observed as part of this survey. In addition, we compare our results with those reported in the literature from data of the Sloan Digital Sky Survey. We have found that when the brightest galaxies and untypical systems are excluded from the sample, a linear relation arises in agreement with what is observed in other groups and clusters. The central regions of the brightest galaxies also follow this relation. In addition, we notice that Virgo contains at least four compact elliptical galaxies besides the well-known object VCC 1297 (NGC 4486B). Their locations in the (μ eff )-luminosity diagram define a trend different from that followed by normal early-type dwarf galaxies, setting an upper limit in effective surface brightness and a lower limit in the effective radius for their luminosities. Based on the distribution of different galaxy sub-samples in the color-magnitude and (μ eff )-luminosity diagrams, we draw some conclusions on their formation and the history of their evolution

Effect of metal opaquer on the final color of 3 ceramic crown types on 3 abutment configurations.

Science.gov (United States)

Arif, Rabia; Yilmaz, Burak; Mortazavi, Aras; Ozcelik, Tuncer B; Johnston, William M

2018-04-30

The effect of a recently introduced metal opaquer when used to mask the color of a titanium abutment under ceramic crown systems is unknown. The purpose of this study was to compare the color coordinates of 3 ceramic crown types-characterized monolithic lithium disilicate (LDC) (IPS e.max; Ivoclar Vivadent AG), layered lithium disilicate (LDL) (IPS e.max; Ivoclar Vivadent AG), and layered zirconia (ZL) (H.C. Starck)-on 3 abutment configurations, nonopaqued titanium (Ti), resin opaqued titanium (Op), and zirconia (Zir). In addition, the color differences (CIEDE2000) were evaluated among the 3 crown types on 3 different abutment substrates. Ten Ti disks (10×1 mm) were fabricated with computer-aided design and computer-aided manufacturing (CAD-CAM) to represent the Ti abutments. Five Ti specimens were opaqued (Op) (whiteMetal Opaquer wMO; Blue Sky Bio), and 5 were not opaqued (Ti). Ten zirconia disks were fabricated with CAD-CAM and sintered (10×1.2 mm). Five disks were used as backings to represent Zir abutments, and 5 disks were layered with 1 mm of porcelain (B1, IPS e.Max Ceram; Ivoclar Vivadent AG) to represent layered zirconia crowns (ZL). Ten lithium disilicate plates (14×14×1.2 mm) were sectioned from CAD blocks (B1 IPS e.Max CAD; Ivoclar Vivadent AG). Five plates were layered with the same porcelain (B1, 1 mm), and 5 plates were surface characterized and glazed. An LDL crown on a Zir abutment configuration was used as the control. The 3 simulated crown types (n=5) were optically connected to each of the 3 abutment types, and the color of the 9 groups was measured using a spectroradiometer. Measured data were reported in CIELab coordinates. CIELab data were used to calculate color differences between the control and the 8 experimental groups. Color data were summarized for each group, and analyzed by repeated-measures ANOVA. For pairwise comparisons, a Bonferroni correction of t tests was used, and for interpretive analysis of resulting color difference

The coloring problem in the solid-state metal boride carbide ScB{sub 2}C{sub 2}. A theoretical analysis

Energy Technology Data Exchange (ETDEWEB)

Lassoued, Souheila [Universite de Rennes, Ecole Nationale Superieure de Chimie, UMR 6226 CNRS (France). Inst. des Sciences Chimiques; Universite Kasdi Merbah-Ouargla (Algeria). Faculte des Mathematiques et des Sciences de la Matiere; Boucher, Benoit [Universite de Rennes, Ecole Nationale Superieure de Chimie, UMR 6226 CNRS (France). Inst. des Sciences Chimiques; Max-Planck-Institut fuer Chemische Physik Fester Stoffe, Dresden (Germany); Boutarfaia, Ahmed [Universite Kasdi Merbah-Ouargla (Algeria). Faculte des Mathematiques et des Sciences de la Matiere; Gautier, Regis; Halet, Jean-Francois [Universite de Rennes, Ecole Nationale Superieure de Chimie, UMR 6226 CNRS (France). Inst. des Sciences Chimiques

2016-08-01

The electronic properties of the layered ternary metal boride carbide ScB{sub 2}C{sub 2}, the structure of which consists of B/C layers made of fused five- and seven-membered rings alternating with scandium sheets, are analyzed. In particular, the respective positions of the B and C atoms (the so-called coloring problem) are tackled using density functional theory, quantum theory of atoms in molecules, and electron localizability indicator calculations. Results reveal that (i) the most stable coloring minimizes the number of B-B and C-C contacts and maximizes the number of boron atoms in the heptagons, (ii) the compound is metallic in character, and (iii) rather important covalent bonding occurs between the metallic sheets and the boron-carbon network.

Relating color working memory and color perception.

Science.gov (United States)

Allred, Sarah R; Flombaum, Jonathan I

2014-11-01

Color is the most frequently studied feature in visual working memory (VWM). Oddly, much of this work de-emphasizes perception, instead making simplifying assumptions about the inputs served to memory. We question these assumptions in light of perception research, and we identify important points of contact between perception and working memory in the case of color. Better characterization of its perceptual inputs will be crucial for elucidating the structure and function of VWM. Copyright © 2014 Elsevier Ltd. All rights reserved.

Color and dichroism of silver-stained glasses

International Nuclear Information System (INIS)

Molina, Gloria; Murcia, Sonia; Molera, Judit; Roldan, Clodoaldo; Crespo, Daniel; Pradell, Trinitat

2013-01-01

Yellow decorations in glasses have been produced since the beginning of the fourteenth century by incorporating metallic silver nanoparticles into the glass (from a few to some tens of nanometers). The optical response of the glass-particles composite is determined by the surface plasmon resonance absorption and scattering of the nanometric metallic particles. Generally, the same color is perceived in reflection and in transmission although dichroic effects are occasionally observed. As silver-stained glasses were designed to be observed in transmission, tuning the transmission color from yellow to red was of technological interest. The relationship between the color observed both in transmission and reflection and the composition and nanostructure of regular (yellow) and dichroic (yellow and red) silver stains from the Renaissance (late fifteenth and sixteenth century, respectively) is related to the presence of a layer (of about 10–20 μm thick) of metallic silver nanoparticles (from few to 100 nm in size). The correlation between the colors observed and the silver stain nanostructure is studied with particular emphasis on the origin of the dichroic behavior. The optical response is computed and compared to the experimental data. Differences in the synthesis parameters responsible for the colors and for the dichroic behavior of the silver stain glasses are proposed. This is essential for the replication of the glass pieces which are required as replacements in the restoration/conservation of the windows but is also of broader interest

Color and dichroism of silver-stained glasses

Energy Technology Data Exchange (ETDEWEB)

Molina, Gloria [Universitat Politecnica de Catalunya, Center for Research in NanoEngineering (Spain); Murcia, Sonia [Universidad de Valencia, Instituto de Ciencia de los Materiales (Spain); Molera, Judit [Universitat de Vic, GRTD, Escola Politecnica Superior (Spain); Roldan, Clodoaldo [Universidad de Valencia, Instituto de Ciencia de los Materiales (Spain); Crespo, Daniel; Pradell, Trinitat, E-mail: Trinitat.Pradell@upc.edu [Universitat Politecnica de Catalunya, Center for Research in NanoEngineering (Spain)

2013-09-15

Yellow decorations in glasses have been produced since the beginning of the fourteenth century by incorporating metallic silver nanoparticles into the glass (from a few to some tens of nanometers). The optical response of the glass-particles composite is determined by the surface plasmon resonance absorption and scattering of the nanometric metallic particles. Generally, the same color is perceived in reflection and in transmission although dichroic effects are occasionally observed. As silver-stained glasses were designed to be observed in transmission, tuning the transmission color from yellow to red was of technological interest. The relationship between the color observed both in transmission and reflection and the composition and nanostructure of regular (yellow) and dichroic (yellow and red) silver stains from the Renaissance (late fifteenth and sixteenth century, respectively) is related to the presence of a layer (of about 10-20 {mu}m thick) of metallic silver nanoparticles (from few to 100 nm in size). The correlation between the colors observed and the silver stain nanostructure is studied with particular emphasis on the origin of the dichroic behavior. The optical response is computed and compared to the experimental data. Differences in the synthesis parameters responsible for the colors and for the dichroic behavior of the silver stain glasses are proposed. This is essential for the replication of the glass pieces which are required as replacements in the restoration/conservation of the windows but is also of broader interest.

COLOR SYSTEMATICS OF COMETS AND RELATED BODIES

Energy Technology Data Exchange (ETDEWEB)

Jewitt, David, E-mail: jewitt@ucla.edu [Department of Earth, Planetary and Space Sciences, UCLA, 595 Charles Young Drive East, Los Angeles, CA 90095-1567 (United States)

2015-12-15

Most comets are volatile-rich bodies that have recently entered the inner solar system following long-term storage in the Kuiper belt and the Oort cloud reservoirs. These reservoirs feed several distinct, short-lived “small body” populations. Here, we present new measurements of the optical colors of cometary and comet-related bodies including long-period (Oort cloud) comets, Damocloids (probable inactive nuclei of long-period comets) and Centaurs (recent escapees from the Kuiper belt and precursors to the Jupiter family comets). We combine the new measurements with published data on short-period comets, Jovian Trojans and Kuiper belt objects to examine the color systematics of the comet-related populations. We find that the mean optical colors of the dust in short-period and long-period comets are identical within the uncertainties of measurement, as are the colors of the dust and of the underlying nuclei. These populations show no evidence for scattering by optically small particles or for compositional gradients, even at the largest distances from the Sun, and no evidence for ultrared matter. Consistent with earlier work, ultrared surfaces are common in the Kuiper belt and on the Centaurs, but not in other small body populations, suggesting that this material is hidden or destroyed upon entry to the inner solar system. The onset of activity in the Centaurs and the disappearance of the ultrared matter in this population begin at about the same perihelion distance (∼10 AU), suggesting that the two are related. Blanketing of primordial surface materials by the fallback of sub-orbital ejecta, for which we calculate a very short timescale, is the likely mechanism. The same process should operate on any mass-losing body, explaining the absence of ultrared surface material in the entire comet population.

Color related to ceramic and zirconia restorations: a review.

Science.gov (United States)

Vichi, Alessandro; Louca, Chris; Corciolani, Gabriele; Ferrari, Marco

2011-01-01

The requirement to achieve natural looking restorations is one of the most challenging aspects of dentistry, and the shade matching of dental restorations with the natural dentition is a difficult task due to the complex optical characteristics of natural teeth. Dental porcelain is considered the reference material for prosthetic rehabilitation, but it is not easy to handle and aesthetic excellence is quite difficult to obtain. For these reasons, shade matching with dental porcelain is often considered to be more artistic than scientific. Shade matching is considered unpredictable due to several variables that may influence the final appearance of a restoration. In order to improve this situation, over the last decade new shade guides and instruments have been developed and the aesthetic aspects of dental porcelain have been further investigated. In this review some aspects of color selection and color reproduction have been examined. Color selection has advanced through the development of new shade guides and electronic shade taking devices, although visual assessment has still not been entirely replaced by electronic instruments. Color reproduction with dental porcelain has improved thanks to advances in the performance and knowledge of dental porcelain, but is still not easy to achieve. The difficulties of achieving good aesthetics with PFM restorations and the desire for metal free solutions have resulted in the increased use of zirconia. The unique optical properties of zirconia have introduced new opportunities for achieving superior aesthetics, however further research is required with this material. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

THE ACS FORNAX CLUSTER SURVEY. X. COLOR GRADIENTS OF GLOBULAR CLUSTER SYSTEMS IN EARLY-TYPE GALAXIES

International Nuclear Information System (INIS)

Liu Chengze; Peng, Eric W.; Jordan, Andres; Ferrarese, Laura; Blakeslee, John P.; Cote, Patrick; Mei, Simona

2011-01-01

We use the largest homogeneous sample of globular clusters (GCs), drawn from the ACS Virgo Cluster Survey (ACSVCS) and ACS Fornax Cluster Survey (ACSFCS), to investigate the color gradients of GC systems in 76 early-type galaxies. We find that most GC systems possess an obvious negative gradient in (g-z) color with radius (bluer outward), which is consistent with previous work. For GC systems displaying color bimodality, both metal-rich and metal-poor GC subpopulations present shallower but significant color gradients on average, and the mean color gradients of these two subpopulations are of roughly equal strength. The field of view of ACS mainly restricts us to measuring the inner gradients of the studied GC systems. These gradients, however, can introduce an aperture bias when measuring the mean colors of GC subpopulations from relatively narrow central pointings. Inferred corrections to previous work imply a reduced significance for the relation between the mean color of metal-poor GCs and their host galaxy luminosity. The GC color gradients also show a dependence with host galaxy mass where the gradients are weakest at the ends of the mass spectrum-in massive galaxies and dwarf galaxies-and strongest in galaxies of intermediate mass, around a stellar mass of M * ∼10 10 M sun . We also measure color gradients for field stars in the host galaxies. We find that GC color gradients are systematically steeper than field star color gradients, but the shape of the gradient-mass relation is the same for both. If gradients are caused by rapid dissipational collapse and weakened by merging, these color gradients support a picture where the inner GC systems of most intermediate-mass and massive galaxies formed early and rapidly with the most massive galaxies having experienced greater merging. The lack of strong gradients in the GC systems of dwarfs, which probably have not experienced many recent major mergers, suggests that low-mass halos were inefficient at retaining

The theory of dissipative structures of the kinetic system for defects of nonlinear physical system 'metal+loading+irradiation'. Part 3

International Nuclear Information System (INIS)

Tarasov, V.A.; Borikov, T.L.; Kryzhanovskaya, T.V.; Chernezhenko, S.A.; Rusov, V.D.

2007-01-01

The kinetic system for defects of physical nonlinear system 'metal + load + irradiation' is specified [1, 2, 3]. Developing the approaches offered in [4], where distinctions of mechanisms of radiating creep and areas of their applicability are formalized (depending on external parameters) for fuel and constructional metals, division of kinetic systems for defects of constructional and fuel metals is carrying out. Thus the accent on the autocatalytic features of kinetic system for defects of reactor fuel metals, resulting from the exoenergic autocatalytic character of nuclear fission reactions being the main point defect source is done. In this part of the article the basic attention is given to the kinetic of sink drains for point defects. For kinetic systems of sinks-sources new approaches for the task of boundary conditions are offered. The possible structure of the computer program modelling kinetic system for defects of nonlinear physical system 'metal + load + irradiation' is considered

EXOPLANET ALBEDO SPECTRA AND COLORS AS A FUNCTION OF PLANET PHASE, SEPARATION, AND METALLICITY

International Nuclear Information System (INIS)

Cahoy, Kerri L.; Marley, Mark S.; Fortney, Jonathan J.

2010-01-01

First generation space-based optical coronagraphic telescopes will obtain images of cool gas- and ice-giant exoplanets around nearby stars. Exoplanets lying at planet-star separations larger than about 1 AU-where an exoplanet can be resolved from its parent star-have spectra that are dominated by reflected light to beyond 1 μm and punctuated by molecular absorption features. Here, we consider how exoplanet albedo spectra and colors vary as a function of planet-star separation, metallicity, mass, and observed phase for Jupiter and Neptune analogs from 0.35 to 1 μm. We model Jupiter analogs with 1x and 3x the solar abundance of heavy elements, and Neptune analogs with 10x and 30x the solar abundance of heavy elements. Our model planets orbit a solar analog parent star at separations of 0.8 AU, 2 AU, 5 AU, and 10 AU. We use a radiative-convective model to compute temperature-pressure profiles. The giant exoplanets are found to be cloud-free at 0.8 AU, possess H 2 O clouds at 2 AU, and have both NH 3 and H 2 O clouds at 5 AU and 10 AU. For each model planet we compute moderate resolution (R = λ/Δλ ∼ 800) albedo spectra as a function of phase. We also consider low-resolution spectra and colors that are more consistent with the capabilities of early direct imaging capabilities. As expected, the presence and vertical structure of clouds strongly influence the albedo spectra since cloud particles not only affect optical depth but also have highly directional scattering properties. Observations at different phases also probe different volumes of atmosphere as the source-observer geometry changes. Because the images of the planets themselves will be unresolved, their phase will not necessarily be immediately obvious, and multiple observations will be needed to discriminate between the effects of planet-star separation, metallicity, and phase on the observed albedo spectra. We consider the range of these combined effects on spectra and colors. For example, we find that

A nonlinear model for ionic polymer metal composites as actuators

Science.gov (United States)

Bonomo, C.; Fortuna, L.; Giannone, P.; Graziani, S.; Strazzeri, S.

2007-02-01

This paper introduces a comprehensive nonlinear dynamic model of motion actuators based on ionic polymer metal composites (IPMCs) working in air. Significant quantities ruling the acting properties of IPMC-based actuators are taken into account. The model is organized as follows. As a first step, the dependence of the IPMC absorbed current on the voltage applied across its thickness is taken into account; a nonlinear circuit model is proposed to describe this relationship. In a second step the transduction of the absorbed current into the IPMC mechanical reaction is modelled. The model resulting from the cascade of both the electrical and the electromechanical stages represents a novel contribution in the field of IPMCs, capable of describing the electromechanical behaviour of these materials and predicting relevant quantities in a large range of applied signals. The effect of actuator scaling is also investigated, giving interesting support to the activities involved in the design of actuating devices based on these novel materials. Evidence of the excellent agreement between the estimations obtained by using the proposed model and experimental signals is given.

Two optical bistability domains in composites of metal nanoparticles with nonlinear dielectric core

Energy Technology Data Exchange (ETDEWEB)

Shewamare, Sisay, E-mail: sisayshewa20@yahoo.com [Department of Physics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia); Mal' nev, V.N., E-mail: vadimnmalnev@yahoo.com [Department of Physics, Addis Ababa University, P.O. Box 1176, Addis Ababa (Ethiopia)

2012-12-15

It is shown that the local field in metal spherical particles with a dielectric core in an external varying electric field has two maxima at two different frequencies. The second maximum becomes more important with an increment in the metal fraction. Due to the nonlinear dielectric function of the core, the composite of these inclusions may have two optically induced bistability domains at different frequencies. At rather high metal fraction, two bistability domains merge and form one entire bistability domain. The parameters of these domains are studied numerically. The paper focuses on the second bistability domain, which has not been discussed in the literature so far. This domain exists in a comparatively narrow frequency range and its onset fields are lower than those of the first bistability domain. The lowest bistability onset fields are obtained in the entire domain. This peculiarity of the optical induced bistability in the metal composite with small dielectric cores can be attractive for possible applications.

Two optical bistability domains in composites of metal nanoparticles with nonlinear dielectric core

International Nuclear Information System (INIS)

Shewamare, Sisay; Mal'nev, V.N.

2012-01-01

It is shown that the local field in metal spherical particles with a dielectric core in an external varying electric field has two maxima at two different frequencies. The second maximum becomes more important with an increment in the metal fraction. Due to the nonlinear dielectric function of the core, the composite of these inclusions may have two optically induced bistability domains at different frequencies. At rather high metal fraction, two bistability domains merge and form one entire bistability domain. The parameters of these domains are studied numerically. The paper focuses on the second bistability domain, which has not been discussed in the literature so far. This domain exists in a comparatively narrow frequency range and its onset fields are lower than those of the first bistability domain. The lowest bistability onset fields are obtained in the entire domain. This peculiarity of the optical induced bistability in the metal composite with small dielectric cores can be attractive for possible applications.

In vitro color evaluation of esthetic coatings for metallic dental implants and implant prosthetic appliances.

Science.gov (United States)

Pecnik, Christina M; Roos, Malgorzata; Muff, Daniel; Spolenak, Ralph; Sailer, Irena

2015-05-01

The aim of this study was to characterize the optical properties of newly developed esthetic coatings for metallic implants and components for an improved peri-implant soft tissue appearance. Pig maxillae (n = 6) were used for the in vitro color evaluation of coated and uncoated samples. Three different coating systems (Ti-ZrO(2), Ti-Al-ZrO(2), and Ti-Ag-ZrO(2)) were deposited on titanium substrates, which exhibited different roughness (polished, machined, and sand-blasted) and interference colors (pink, yellow, and white). Spectrophotometric measurements were made of samples below three different mucosa thicknesses (1 mm, 2 mm, and 3 mm) and titanium served as negative control. Color difference ΔE was calculated using ΔL, Δa, and Δb values for each sample (in total 30 samples). ΔE values were significantly above the threshold value of 3.70 for sand-blasted Ti and Ti-ZrO(2) samples when tested below 1 mm thick soft tissue, hence resulted in a dark appearance of the soft tissues. In contrast, Ti-Al-ZrO(2) and Ti-Ag-ZrO(2) samples showed significant ΔL values below 1 mm, which indicates a brightening of the covering tissue. In general, ΔE values decreased with increasing thickness of the tissue. At 3 mm thick tissue, ΔE values were significantly below 3.70 for Ti-Al-ZrO(2) and Ti-Ag-ZrO(2) samples. The preferable substrate surface should be machined due increased color brightness, good soft tissue integration and improved adhesion between coating and substrates. Improvement of the optical appearance of the metal was achieved with the coating systems Ti-Al-ZrO(2) and Ti-Ag-ZrO(2). Darkening effects could not be observed for these systems, and partially light brightening of the tissue was observed. Advantageous colors were suggested to be pink and yellow. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Anti-Counterfeiting Quick Response Code with Emission Color of Invisible Metal-Organic Frameworks as Encoding Information.

Science.gov (United States)

Wang, Yong-Mei; Tian, Xue-Tao; Zhang, Hui; Yang, Zhong-Rui; Yin, Xue-Bo

2018-06-08

Counterfeiting is a global epidemic that is compelling the development of new anti-counterfeiting strategy. Herein, we report a novel multiple anti-counterfeiting encoding strategy of invisible fluorescent quick response (QR) codes with emission color as information storage unit. The strategy requires red, green, and blue (RGB) light-emitting materials for different emission colors as encrypting information, single excitation for all of the emission for practicability, and ultraviolet (UV) excitation for invisibility under slight. Therefore, RGB light-emitting nanoscale metal-organic frameworks (NMOFs) are designed as inks to construct the colorful light-emitting boxes for information encrypting, while three black vertex boxes were used for positioning. Full-color emissions are obtained by mixing the trichromatic NMOFs inks through inkjet printer. The encrypting information capacity is easily adjusted by the number of light-emitting boxes with the infinite emission colors. The information is decoded with specific excitation light at 275 nm, making the QR codes invisible under daylight. The composition of inks, invisibility, inkjet printing, and the abundant encrypting information all contribute to multiple anti-counterfeiting. The proposed QR codes pattern holds great potential for advanced anti-counterfeiting.

The Relation between Children's Conceptual Functioning with Color and Color Term Acquisition

Science.gov (United States)

Kowalski, Kurt; Zimiles, Herbert

2006-01-01

Young children experience considerable difficulty in learning their first few color terms. One explanation for this difficulty is that initially they lack a conceptual representation of color sufficiently abstract to support word meaning. This hypothesis, that prior to learning color terms children do not represent color as an abstraction, was…

Note on off-shell relations in nonlinear sigma model

International Nuclear Information System (INIS)

Chen, Gang; Du, Yi-Jian; Li, Shuyi; Liu, Hanqing

2015-01-01

In this note, we investigate relations between tree-level off-shell currents in nonlinear sigma model. Under Cayley parametrization, all odd-point currents vanish. We propose and prove a generalized U(1) identity for even-point currents. The off-shell U(1) identity given in http://dx.doi.org/10.1007/JHEP01(2014)061 is a special case of the generalized identity studied in this note. The on-shell limit of this identity is equivalent with the on-shell KK relation. Thus this relation provides the full off-shell correspondence of tree-level KK relation in nonlinear sigma model.

Flare-related color effects in UV Ceti stars

International Nuclear Information System (INIS)

Flesch, T.R.

1975-01-01

The UV Ceti flare stars YZ CMi, BD+16 0 2708, EV Lac, and AD Leo were monitored photoelectrically for flare activity with the 76 centimeter reflecting telescope of the University of Florida's Rosemary Hill Observatory. Observations were carried out from January, 1973 to April, 1975. The instrumentation allowed simultaneous readings to be taken at 3500, 4632, and 6496A with a time resolution of 2 seconds. A total of 15 major events were observed, with 14 of these being observed in all three colors. All events showed the classical fast rise and slower decline that is typical of this type of activity. One event showed peculiar behavior in the red bandpass that may indicate strong dependence of the flare light in some cases on line emission. The data were applied to the fast electron model of flare activity proposed by Gurzadyan. Several serious inconsistencies in the theory were found that would not have been evident in single-channel monitoring. No event could be fitted in all three colors using consistent values of the unknown parameters in the theory. The most serious deficiencies in the theory were the wavelength dependence of the optical depth of the electron cloud and the lack of treatment of line emission behavior. Differential color indices for flare light are calculated and are shown to be essentially constant throughout the entire event for the stronger flares. A color-color plot of the flare light at maximum reveals that 11 of the flares show a linear relation. This relation indicates that the smaller the u-b index, the larger is the b-r index. This is probably directly involved with line emission during flare events. Future research possibilities are discussed, with spectroscopic studies and simultaneous multicolor observations being stressed

Thin films of metal-organic compounds and metal nanoparticle

Indian Academy of Sciences (India)

Thin films of metal-organic compounds and metal nanoparticle-embedded polymers for nonlinear optical applications. S Philip Anthony Shatabdi Porel D ... Thin films based on two very different metal-organic systems are developed and some nonlinear optical applications are explored. A family of zinc complexes which ...

Chaos resulting from nonlinear relations between different variables

International Nuclear Information System (INIS)

Dohtani, Akitaka

2011-01-01

Research highlights: → We prove a general result on the existence of chaos. → We focus on the cyclic composites of interdependent relations between different variables. → By considering several examples, we conclude that the cyclic composites play an important role in detecting chaotic dynamics. - Abstract: In this study, we further develop the perturbation method of Marotto and investigate the general mechanisms responsible for nonlinear dynamics, which are typical of multidimensional systems. We focus on the composites of interdependent relations between different variables. First, we prove a general result on chaos, which shows that the cyclic composites of nonlinear interdependent relations are sources of chaotic dynamics in multidimensional systems. By considering several examples, we conclude that the cyclic composites play an important role in detecting chaotic dynamics.

Spatial patterns of correlated scale size and scale color in relation to color pattern elements in butterfly wings.

Science.gov (United States)

Iwata, Masaki; Otaki, Joji M

2016-02-01

Complex butterfly wing color patterns are coordinated throughout a wing by unknown mechanisms that provide undifferentiated immature scale cells with positional information for scale color. Because there is a reasonable level of correspondence between the color pattern element and scale size at least in Junonia orithya and Junonia oenone, a single morphogenic signal may contain positional information for both color and size. However, this color-size relationship has not been demonstrated in other species of the family Nymphalidae. Here, we investigated the distribution patterns of scale size in relation to color pattern elements on the hindwings of the peacock pansy butterfly Junonia almana, together with other nymphalid butterflies, Vanessa indica and Danaus chrysippus. In these species, we observed a general decrease in scale size from the basal to the distal areas, although the size gradient was small in D. chrysippus. Scales of dark color in color pattern elements, including eyespot black rings, parafocal elements, and submarginal bands, were larger than those of their surroundings. Within an eyespot, the largest scales were found at the focal white area, although there were exceptional cases. Similarly, ectopic eyespots that were induced by physical damage on the J. almana background area had larger scales than in the surrounding area. These results are consistent with the previous finding that scale color and size coordinate to form color pattern elements. We propose a ploidy hypothesis to explain the color-size relationship in which the putative morphogenic signal induces the polyploidization (genome amplification) of immature scale cells and that the degrees of ploidy (gene dosage) determine scale color and scale size simultaneously in butterfly wings. Copyright © 2015 Elsevier Ltd. All rights reserved.

Plasmonic- and dielectric-based structural coloring: from fundamentals to practical applications

Science.gov (United States)

Lee, Taejun; Jang, Jaehyuck; Jeong, Heonyeong; Rho, Junsuk

2018-01-01

Structural coloring is production of color by surfaces that have microstructure fine enough to interfere with visible light; this phenomenon provides a novel paradigm for color printing. Plasmonic color is an emergent property of the interaction between light and metallic surfaces. This phenomenon can surpass the diffraction limit and achieve near unlimited lifetime. We categorize plasmonic color filters according to their designs (hole, rod, metal-insulator-metal, grating), and also describe structures supported by Mie resonance. We discuss the principles, and the merits and demerits of each color filter. We also discuss a new concept of color filters with tunability and reconfigurability, which enable printing of structural color to yield dynamic coloring at will. Approaches for dynamic coloring are classified as liquid crystal, chemical transition and mechanical deformation. At the end of review, we highlight a scale-up of fabrication methods, including nanoimprinting, self-assembly and laser-induced process that may enable real-world application of structural coloring.

A nonlinear deformed su(2) algebra with a two-color quasitriangular Hopf structure

International Nuclear Information System (INIS)

Bonatsos, D.; Daskaloyannis, C.; Kolokotronis, P.; Ludu, A.; Quesne, C.

1997-01-01

Nonlinear deformations of the enveloping algebra of su(2), involving two arbitrary functions of J 0 and generalizing the Witten algebra, were introduced some time ago by Delbecq and Quesne. In the present paper, the problem of endowing some of them with a Hopf algebraic structure is addressed by studying in detail a specific example, referred to as scr(A) q + (1). This algebra is shown to possess two series of (N+1)-dimensional unitary irreducible representations, where N=0,1,2,hor-ellipsis. To allow the coupling of any two such representations, a generalization of the standard Hopf axioms is proposed by proceeding in two steps. In the first one, a variant and extension of the deforming functional technique is introduced: variant because a map between two deformed algebras, su q (2) and scr(A) q + (1), is considered instead of a map between a Lie algebra and a deformed one, and extension because use is made of a two-valued functional, whose inverse is singular. As a result, the Hopf structure of su q (2) is carried over to scr(A) q + (1), thereby endowing the latter with a double Hopf structure. In the second step, the definition of the coproduct, counit, antipode, and scr(R)-matrix is extended so that the double Hopf algebra is enlarged into a new algebraic structure. The latter is referred to as a two-color quasitriangular Hopf algebra because the corresponding scr(R)-matrix is a solution of the colored Yang endash Baxter equation, where the open-quotes colorclose quotes parameters take two discrete values associated with the two series of finite-dimensional representations. copyright 1997 American Institute of Physics

Data-driven modeling of background and mine-related acidity and metals in river basins

International Nuclear Information System (INIS)

Friedel, Michael J.

2014-01-01

A novel application of self-organizing map (SOM) and multivariate statistical techniques is used to model the nonlinear interaction among basin mineral-resources, mining activity, and surface-water quality. First, the SOM is trained using sparse measurements from 228 sample sites in the Animas River Basin, Colorado. The model performance is validated by comparing stochastic predictions of basin-alteration assemblages and mining activity at 104 independent sites. The SOM correctly predicts (>98%) the predominant type of basin hydrothermal alteration and presence (or absence) of mining activity. Second, application of the Davies–Bouldin criteria to k-means clustering of SOM neurons identified ten unique environmental groups. Median statistics of these groups define a nonlinear water-quality response along the spatiotemporal hydrothermal alteration-mining gradient. These results reveal that it is possible to differentiate among the continuum between inputs of background and mine-related acidity and metals, and it provides a basis for future research and empirical model development. The trained self-organizing map is used to determine upstream hydrothermal alteration (AS – acid sulfate; PROP – propylitic, PROP-V – propylitic veins, QSP – quartz-sericite-pyrite, WSP – weak-sericite-pyrite; Mining activity: MINES) from water-quality measurements in the Animas river basin, Colorado, USA. The white hexagons are sized proportional to the number of water-quality samples associated with that SOM neuron. Highlights: • We model surface-water quality response using a self-organizing map and multivariate statistics. • Applying Davies–Bouldin criteria to k-means clusters defines ten environmental response groups. • The approach differentiates between background and mine-related acidity and metals. -- These results reveal that it is possible to differentiate among the continuum between inputs of background and mine-related acidity and metals

OPTICAL-NEAR-INFRARED COLOR GRADIENTS AND MERGING HISTORY OF ELLIPTICAL GALAXIES

International Nuclear Information System (INIS)

Kim, Duho; Im, Myungshin

2013-01-01

It has been suggested that merging plays an important role in the formation and the evolution of elliptical galaxies. While gas dissipation by star formation is believed to steepen metallicity and color gradients of the merger products, mixing of stars through dissipation-less merging (dry merging) is believed to flatten them. In order to understand the past merging history of elliptical galaxies, we studied the optical-near-infrared (NIR) color gradients of 204 elliptical galaxies. These galaxies are selected from the overlap region of the Sloan Digital Sky Survey (SDSS) Stripe 82 and the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). The use of optical and NIR data (g, r, and K) provides large wavelength baselines, and breaks the age-metallicity degeneracy, allowing us to derive age and metallicity gradients. The use of the deep SDSS Stripe 82 images makes it possible for us to examine how the color/age/metallicity gradients are related to merging features. We find that the optical-NIR color and the age/metallicity gradients of elliptical galaxies with tidal features are consistent with those of relaxed ellipticals, suggesting that the two populations underwent a similar merging history on average and that mixing of stars was more or less completed before the tidal features disappeared. Elliptical galaxies with dust features have steeper color gradients than the other two types, even after masking out dust features during the analysis, which can be due to a process involving wet merging. More importantly, we find that the scatter in the color/age/metallicity gradients of the relaxed and merging feature types decreases as their luminosities (or masses) increase at M > 10 11.4 M ☉ but stays large at lower luminosities. Mean metallicity gradients appear nearly constant over the explored mass range, but a possible flattening is observed at the massive end. According to our toy model that predicts how the distribution of metallicity gradients

Nonlinear operators and nonlinear transformations studied via the differential form of the completeness relation in quantum mechanics

International Nuclear Information System (INIS)

Fan Hongyi; Yu Shenxi

1994-01-01

We show that the differential form of the fundamental completeness relation in quantum mechanics and the technique of differentiation within an ordered product (DWOP) of operators provide a new approach for calculating normal product expansions of some nonlinear operators and study some nonlinear transformations. Their usefulness in perturbative calculations is pointed out. (orig.)

Identification of non-linear kinematic hardening with bending and unbending tests in anisotropic sheet-metals

International Nuclear Information System (INIS)

Brunet, M.; Morestin, F.; Godereaux, S.

2000-01-01

An inverse identification technique is proposed based on bending-unbending experiments on anisotropic sheet-metal strips. The initial anisotropy theory of plasticity is extended to include the concept of combined isotropic and non-linear kinematic hardening. This theory is adopted to characterise the anisotropic hardening due to loading-unloading which occurs in sheet-metal forming processes. To this end, a specific bending-unbending apparatus has been built to provide experimental moment-curvature curves. The constant bending moment applied over the length of the specimen to determine numerically the strain-stress behaviour but without Finite Element Analysis. Four constitutive parameters have to be identified by an inverse approach. Our identification results show that bending-unbending tests are suitable to model quite accurately the constitutive behaviour of sheet metals under complex loading paths. (author)

Children's Book Color Preferences as Related to Their Favorite Color.

Science.gov (United States)

Locke, Jill L.

Because young children disregard writing on the spine of a book, researchers chose to run a test on color preferences in books. In a library situation young children see most books from a spine-out angle; thus when allowed to select a book by themselves, the first characteristics noticed are size and color. This study is based on the hypothesis…

Period--luminosity--color relations and pulsation modes of pulsating variable stars

International Nuclear Information System (INIS)

Breger, M.; Bregman, J.N.

1975-01-01

The periods of delta Scuti, RR Lyrae, dwarf Cepheid, and W Virginis variables have been investigated for their dependence on luminosity, color, mass, and pulsation modes. A maximum-likelihood method, which includes consideration of the observational errors in each coordinate, has been applied to obtain observational period-luminosity-color (P-L-C) relations

PERIOD–COLOR AND AMPLITUDE–COLOR RELATIONS AT MAXIMUM AND MINIMUM LIGHT FOR RR LYRAE STARS IN THE SDSS STRIPE 82 REGION

Energy Technology Data Exchange (ETDEWEB)

Ngeow, Chow-Choong [Graduate Institute of Astronomy, National Central University, Jhongli 32001, Taiwan (China); Kanbur, Shashi M.; Schrecengost, Zachariah [Department of Physics, SUNY Oswego, Oswego, NY 13126 (United States); Bhardwaj, Anupam; Singh, Harinder P. [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India)

2017-01-10

Investigation of period–color (PC) and amplitude–color (AC) relations at the maximum and minimum light can be used to probe the interaction of the hydrogen ionization front (HIF) with the photosphere and the radiation hydrodynamics of the outer envelopes of Cepheids and RR Lyraes. For example, theoretical calculations indicated that such interactions would occur at minimum light for RR Lyrae and result in a flatter PC relation. In the past, the PC and AC relations have been investigated by using either the ( V − R ){sub MACHO} or ( V − I ) colors. In this work, we extend previous work to other bands by analyzing the RR Lyraes in the Sloan Digital Sky Survey Stripe 82 Region. Multi-epoch data are available for RR Lyraes located within the footprint of the Stripe 82 Region in five ( ugriz ) bands. We present the PC and AC relations at maximum and minimum light in four colors: ( u − g ){sub 0}, ( g − r ){sub 0}, ( r − i ){sub 0}, and ( i − z ){sub 0}, after they are corrected for extinction. We found that the PC and AC relations for this sample of RR Lyraes show a complex nature in the form of flat, linear or quadratic relations. Furthermore, the PC relations at minimum light for fundamental mode RR Lyrae stars are separated according to the Oosterhoff type, especially in the ( g − r ){sub 0} and ( r − i ){sub 0} colors. If only considering the results from linear regressions, our results are quantitatively consistent with the theory of HIF-photosphere interaction for both fundamental and first overtone RR Lyraes.

Relative controllability of nonlinear neutral systems with distributed ...

African Journals Online (AJOL)

In this paper we study the relative controllability of nonlinear neutral system with distributed and multiple lumped time varying delays in control. Using Schauder's fixed point theorem sufficient conditions for relative controllability in a given time interval are formulated and proved. Journal of the Nigerian Association of ...

The nonlinear effects on the characteristics of gravity wave packets: dispersion and polarization relations

Directory of Open Access Journals (Sweden)

S.-D. Zhang

2000-10-01

Full Text Available By analyzing the results of the numerical simulations of nonlinear propagation of three Gaussian gravity-wave packets in isothermal atmosphere individually, the nonlinear effects on the characteristics of gravity waves are studied quantitatively. The analyses show that during the nonlinear propagation of gravity wave packets the mean flows are accelerated and the vertical wavelengths show clear reduction due to nonlinearity. On the other hand, though nonlinear effects exist, the time variations of the frequencies of gravity wave packets are close to those derived from the dispersion relation and the amplitude and phase relations of wave-associated disturbance components are consistent with the predictions of the polarization relation of gravity waves. This indicates that the dispersion and polarization relations based on the linear gravity wave theory can be applied extensively in the nonlinear region.Key words: Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides

Study of chromatic adaptation using memory color matches, Part II: colored illuminants.

Science.gov (United States)

Smet, Kevin A G; Zhai, Qiyan; Luo, Ming R; Hanselaer, Peter

2017-04-03

In a previous paper, 12 corresponding color data sets were derived for 4 neutral illuminants using the long-term memory colours of five familiar objects. The data were used to test several linear (one-step and two-step von Kries, RLAB) and nonlinear (Hunt and Nayatani) chromatic adaptation transforms (CAT). This paper extends that study to a total of 156 corresponding color sets by including 9 more colored illuminants: 2 with low and 2 with high correlated color temperatures as well as 5 representing high chroma adaptive conditions. As in the previous study, a two-step von Kries transform whereby the degree of adaptation D is optimized to minimize the DEu'v' prediction errors outperformed all other tested models for both memory color and literature corresponding color sets, whereby prediction errors were lower for the memory color set. Most of the transforms tested, except the two- and one-step von Kries models with optimized D, showed large errors for corresponding color subsets that contained non-neutral adaptive conditions as all of them tended to overestimate the effective degree of adaptation in this study. An analysis of the impact of the sensor space primaries in which the adaptation is performed was found to have little impact compared to that of model choice. Finally, the effective degree of adaptation for the 13 illumination conditions (4 neutral + 9 colored) was successfully modelled using a bivariate Gaussian in a Macleod-Boyton like chromaticity diagram.

Perceptual distortion analysis of color image VQ-based coding

Science.gov (United States)

Charrier, Christophe; Knoblauch, Kenneth; Cherifi, Hocine

1997-04-01

It is generally accepted that a RGB color image can be easily encoded by using a gray-scale compression technique on each of the three color planes. Such an approach, however, fails to take into account correlations existing between color planes and perceptual factors. We evaluated several linear and non-linear color spaces, some introduced by the CIE, compressed with the vector quantization technique for minimum perceptual distortion. To study these distortions, we measured contrast and luminance of the video framebuffer, to precisely control color. We then obtained psychophysical judgements to measure how well these methods work to minimize perceptual distortion in a variety of color space.

A study on the treatment process of industrial wastewater related to heavy metal wastewater

International Nuclear Information System (INIS)

Park, J. J.; Shin, J. M.; Kim, J. H.; Yang, M. S.; Kim, M. J.; Son, J. S.; Park, H. S.

1999-08-01

The supernatant from metal wastewater by using magnesium hydroxide and dolomite was used to treat dyeing wastewater. In the case of magnesium hydroxide. In the case of magnesium hydroxide, the optimum dosage was 10 % (v/v) for supernatant A and 3 % (v/v) for separation B. Color turbidity and COD removal was 99 to 100 % , 85 to 97 % and 43 to 53 %, respectively. In the case of dolomite, the optimum dosage was 30 % (v/v) for supernatant A and 3% for supernatant B. Color, turbidity and COD removal was 96 to 99 %, 62 to 91 % and 52 to 53 %, respectively. In dyeing wastewater treatment by using supernatant from metal wastewater, the cost of chemicals was reduced by about 80 %

Methods for computing color anaglyphs

Science.gov (United States)

McAllister, David F.; Zhou, Ya; Sullivan, Sophia

2010-02-01

A new computation technique is presented for calculating pixel colors in anaglyph images. The method depends upon knowing the RGB spectral distributions of the display device and the transmission functions of the filters in the viewing glasses. It requires the solution of a nonlinear least-squares program for each pixel in a stereo pair and is based on minimizing color distances in the CIEL*a*b* uniform color space. The method is compared with several techniques for computing anaglyphs including approximation in CIE space using the Euclidean and Uniform metrics, the Photoshop method and its variants, and a method proposed by Peter Wimmer. We also discuss the methods of desaturation and gamma correction for reducing retinal rivalry.

Tuning the Color of Silicon Nanostructures

KAUST Repository

Cao, Linyou; Fan, Pengyu; Barnard, Edward S.; Brown, Ana M.; Brongersma, Mark L.

2010-01-01

and Si structures have already been engineered to enable light emission, optical cloaking, waveguiding, nonlinear optics, enhanced light absorption, and sensing. Here, we demonstrate that a wide spectrum of colors can be generated by harnessing the strong

Dimensionality of heavy metal distribution in waste disposal sites using nonlinear dynamics

International Nuclear Information System (INIS)

Modis, Kostas; Komnitsas, Kostas

2008-01-01

Mapping of heavy metal contamination in mining and waste disposal sites usually relies on geostatistical approaches and linear stochastic dynamics. The present paper aims to identify, using the Grassberger-Procaccia correlation dimension (CD) algorithm, the existence of a nonlinear deterministic and chaotic dynamic behaviour in the spatial pattern of arsenic, manganese and zinc concentration in a Russian coal waste disposal site. The analysis carried out yielded embedding dimension values ranging between 7 and 8 suggesting thus from a chaotic dynamic perspective that arsenic, manganese and zinc concentration in space is a medium dimensional problem for the regionalized scale considered in this study. This alternative nonlinear dynamics approach may complement conventional geostatistical studies and may be also used for the estimation of risk and the subsequent screening and selection of a feasible remediation scheme in wider mining and waste disposal sites. Finally, the synergistic effect of this study may be further elaborated if additional factors including among others presence of hot spots, density and depth of sampling, mineralogy of wastes and sensitivity of analytical techniques are taken into account

On a New Theoretical Framework for RR Lyrae Stars. II. Mid-infrared Period–Luminosity–Metallicity Relations

Energy Technology Data Exchange (ETDEWEB)

Neeley, Jillian R.; Marengo, Massimo; Trueba, Nicolas [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Bono, Giuseppe; Braga, Vittorio F.; Magurno, Davide [Department of Physics, Università di Roma Tor Vergara, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Dall’Ora, Massimo; Marconi, Marcella [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiarello 16, I-80131 Napoli (Italy); Tognelli, Emanuele; Moroni, Pier G. Prada [Dipartimento di Fisica, Università di Pisa, Lago Bruno Pontecorvo 3, I-56127, Pisa (Italy); Beaton, Rachael L.; Madore, Barry F.; Seibert, Mark [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Freedman, Wendy L. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Monson, Andrew J. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Scowcroft, Victoria [Department of Physics, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Stetson, Peter B., E-mail: jrneeley@iastate.edu [NRC-Herzberg, Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria BC V9E 2E7 (Canada)

2017-06-01

We present new theoretical period–luminosity–metallicity (PLZ) relations for RR Lyræ stars (RRLs) at Spitzer and WISE wavelengths. The PLZ relations were derived using nonlinear, time-dependent convective hydrodynamical models for a broad range of metal abundances ( Z = 0.0001–0.0198). In deriving the light curves, we tested two sets of atmospheric models and found no significant difference between the resulting mean magnitudes. We also compare our theoretical relations to empirical relations derived from RRLs in both the field and in the globular cluster M4. Our theoretical PLZ relations were combined with multi-wavelength observations to simultaneously fit the distance modulus, μ {sub 0}, and extinction, A {sub V}, of both the individual Galactic RRL and of the cluster M4. The results for the Galactic RRL are consistent with trigonometric parallax measurements from Gaia ’ s first data release. For M4, we find a distance modulus of μ {sub 0} = 11.257 ± 0.035 mag with A {sub V}= 1.45 ± 0.12 mag, which is consistent with measurements from other distance indicators. This analysis has shown that, when considering a sample covering a range of iron abundances, the metallicity spread introduces a dispersion in the PL relation on the order of 0.13 mag. However, if this metallicity component is accounted for in a PLZ relation, the dispersion is reduced to ∼0.02 mag at mid-infrared wavelengths.

Two-color walking Peregrine solitary waves.

Science.gov (United States)

Baronio, Fabio; Chen, Shihua; Mihalache, Dumitru

2017-09-15

We study the extreme localization of light, evolving upon a non-zero background, in two-color parametric wave interaction in nonlinear quadratic media. We report the existence of quadratic Peregrine solitary waves, in the presence of significant group-velocity mismatch between the waves (or Poynting vector beam walk-off), in the regime of cascading second-harmonic generation. This finding opens a novel path for the experimental demonstration of extreme rogue waves in ultrafast quadratic nonlinear optics.

TOOTH COLOR AND REFLECTANCE AS RELATED TO LIGHT-SCATTERING AND ENAMEL HARDNESS

NARCIS (Netherlands)

TENBOSCH, JJ; COOPS, JC

Tooth color is determined by the paths of light inside the tooth and absorption along these paths. This paper tests the hypothesis that, since the paths are determined by scattering, a relation between color and scattering coefficients exists. One hundred and two extracted incisors were fixed in

Predicting transmittance spectra of electrophotographic color prints

Science.gov (United States)

Mourad, Safer; Emmel, Patrick; Hersch, Roger D.

2000-12-01

For dry toner electrophotographic color printers, we present a numerical simulation model describing the color printer responses based on a physical characterization of the different electrophotographic process steps. The proposed model introduces a Cross Transfer Efficiency designed to predict the color transmittance spectra of multi-color prints by taking into account the transfer influence of each deposited color toner layer upon the other layers. The simulation model leads to a better understanding of the factors that have an impact on printing quality. In order to avoid the additional optical non-linearities produced by light reflection on paper, we have limited the present investigation to transparency prints. The proposed model succeeded to predict the transmittance spectra of printed wedges combining two color toner layers with a mean deviation less than CIE-LAB (Delta) E equals 2.5.

Nonlinear Supersymmetric General Relativity and Unity of Nature

OpenAIRE

Shima, Kazunari; Tsuda, Motomu

2008-01-01

The basic idea and some physical implications of nonlinear supersymmetric general relativity (NLSUSY GR) are discussed, which give new insights into the origin of mass and the mysterious relations between the cosmology and the low energy particle physics, e.g. the spontaneous SUSY breaking scale, the cosmological constant, the (dark) energy density of the universe and the neutrino mass.

Improved linearity in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors with nonlinear polarization dielectric

International Nuclear Information System (INIS)

Gao, Tao; Xu, Ruimin; Kong, Yuechan; Zhou, Jianjun; Kong, Cen; Dong, Xun; Chen, Tangsheng

2015-01-01

We demonstrate highly improved linearity in a nonlinear ferroelectric of Pb(Zr 0.52 Ti 0.48 )-gated AlGaN/GaN metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT). Distinct double-hump feature in the transconductance-gate voltage (g m -V g ) curve is observed, yielding remarkable enhancement in gate voltage swing as compared to MIS-HEMT with conventional linear gate dielectric. By incorporating the ferroelectric polarization into a self-consistent calculation, it is disclosed that in addition to the common hump corresponding to the onset of electron accumulation, the second hump at high current level is originated from the nonlinear polar nature of ferroelectric, which enhances the gate capacitance by increasing equivalent dielectric constant nonlinearly. This work paves a way for design of high linearity GaN MIS-HEMT by exploiting the nonlinear properties of dielectric

A nanohole in a thin metal film as an efficient nonlinear optical element

International Nuclear Information System (INIS)

Konstantinova, T. V.; Melent’ev, P. N.; Afanas’ev, A. E.; Kuzin, A. A.; Starikov, P. A.; Baturin, A. S.; Tausenev, A. V.; Konyashchenko, A. V.; Balykin, V. I.

2013-01-01

The nonlinear optical properties of single nanoholes and nanoslits fabricated in gold and aluminum nanofilms are studied by third harmonic generation (THG). It is shown that the extremely high third-order optical susceptibility of aluminum and the presence of strong plasmon resonance of a single nanohole in an aluminum film make possible an efficient nanolocalized radiation source at the third harmonic frequency. The THG efficiency for a single nanohole in a thin metal film can be close to unity for an exciting laser radiation intensity on the order of 10 13 W/cm 2

Plasmonic color metasurfaces fabricated by a high speed roll-to-roll method

DEFF Research Database (Denmark)

Murthy, Swathi; Pranov, Henrik; Feidenhans'l, Nikolaj Agentoft

2017-01-01

Lab-scale plasmonic color printing using nano-structured and subsequently metallized surfaces have been demonstrated to provide vivid colors. However, upscaling these structures for large area manufacturing is extremely challenging due to the requirement of nanometer precision of metal thickness....... In this study, we have investigated a plasmonic color meta-surface design that can be easily upscaled. We have demonstrated the feasibility of fabrication of these plasmonic color surfaces by a high-speed roll-to-roll method, comprising roll-to-roll extrusion coating at 10 m min-1 creating a polymer foil having...... 100 nm deep pits of varying sub-wavelength diameter and pitch length. Subsequently this polymer foil was metallized and coated also by high-speed roll-to-roll methods. The perceived colors have high tolerance towards the thickness of the metal layer, when this thickness exceeds the depths of the pits...

Do focal colors look particularly "colorful"?

Science.gov (United States)

Witzel, Christoph; Franklin, Anna

2014-04-01

If the most typical red, yellow, green, and blue were particularly colorful (i.e., saturated), they would "jump out to the eye." This would explain why even fundamentally different languages have distinct color terms for these focal colors, and why unique hues play a prominent role in subjective color appearance. In this study, the subjective saturation of 10 colors around each of these focal colors was measured through a pairwise matching task. Results show that subjective saturation changes systematically across hues in a way that is strongly correlated to the visual gamut, and exponentially related to sensitivity but not to focal colors.

Color Terms and Color Concepts

Science.gov (United States)

Davidoff, Jules

2006-01-01

In their lead articles, both Kowalski and Zimiles (2006) and O'Hanlon and Roberson (2006) declare a general relation between color term knowledge and the ability to conceptually represent color. Kowalski and Zimiles, in particular, argue for a priority for the conceptual representation in color term acquisition. The complexities of the interaction…

Nonlinear waves in waveguides with stratification

CERN Document Server

Leble, Sergei B

1991-01-01

S.B. Leble's book deals with nonlinear waves and their propagation in metallic and dielectric waveguides and media with stratification. The underlying nonlinear evolution equations (NEEs) are derived giving also their solutions for specific situations. The reader will find new elements to the traditional approach. Various dispersion and relaxation laws for different guides are considered as well as the explicit form of projection operators, NEEs, quasi-solitons and of Darboux transforms. Special points relate to: 1. the development of a universal asymptotic method of deriving NEEs for guide propagation; 2. applications to the cases of stratified liquids, gases, solids and plasmas with various nonlinearities and dispersion laws; 3. connections between the basic problem and soliton- like solutions of the corresponding NEEs; 4. discussion of details of simple solutions in higher- order nonsingular perturbation theory.

Color selectivity of surface-plasmon holograms illuminated with white light.

Science.gov (United States)

Ozaki, Miyu; Kato, Jun-ichi; Kawata, Satoshi

2013-09-20

By using the optical frequency dependence of surface-plasmon polaritons, color images can be reconstructed from holograms illuminated with white light. We report details on the color selectivity of the color holograms. The selectivity is tuned by the thickness of a dielectric film covering a plasmonic metal film. When the dielectric is SiO(2) and the metal is silver, the appropriate thicknesses are 25 and 55 nm, respectively. In terms of spatial color uniformity, holograms made of silver-film corrugations are better than holograms recorded on photographic film on a flat silver surface.

Nonlinear association criterion, nonlinear Granger causality and related issues with applications to neuroimage studies.

Science.gov (United States)

Tao, Chenyang; Feng, Jianfeng

2016-03-15

Quantifying associations in neuroscience (and many other scientific disciplines) is often challenged by high-dimensionality, nonlinearity and noisy observations. Many classic methods have either poor power or poor scalability on data sets of the same or different scales such as genetical, physiological and image data. Based on the framework of reproducing kernel Hilbert spaces we proposed a new nonlinear association criteria (NAC) with an efficient numerical algorithm and p-value approximation scheme. We also presented mathematical justification that links the proposed method to related methods such as kernel generalized variance, kernel canonical correlation analysis and Hilbert-Schmidt independence criteria. NAC allows the detection of association between arbitrary input domain as long as a characteristic kernel is defined. A MATLAB package was provided to facilitate applications. Extensive simulation examples and four real world neuroscience examples including functional MRI causality, Calcium imaging and imaging genetic studies on autism [Brain, 138(5):13821393 (2015)] and alcohol addiction [PNAS, 112(30):E4085-E4093 (2015)] are used to benchmark NAC. It demonstrates the superior performance over the existing procedures we tested and also yields biologically significant results for the real world examples. NAC beats its linear counterparts when nonlinearity is presented in the data. It also shows more robustness against different experimental setups compared with its nonlinear counterparts. In this work we presented a new and robust statistical approach NAC for measuring associations. It could serve as an interesting alternative to the existing methods for datasets where nonlinearity and other confounding factors are present. Copyright © 2016 Elsevier B.V. All rights reserved.

An Examination of Color-Blind Racism and Race-Related Stress among African American Undergraduate Students

Science.gov (United States)

Coleman, M. Nicole; Chapman, Stephanie; Wang, David C.

2013-01-01

This study examined the role of color-blind racial ideology among a sample of 152 African American undergraduate students in relation to race-related stress. We hypothesized that those who endorsed relatively higher color-blind racial attitudes would experience greater race-related stress because experiences with racism would be interpreted as…

Color Memory of University Students: Influence of Color Experience and Color Characteristic

Science.gov (United States)

Bynum, Carlisle; Epps, Helen H.; Kaya, Naz

2006-01-01

The ability to select a previously viewed color specimen from an array of specimens that differ in hue, value, or chroma varies among individuals, and may be related to one's basic color discrimination ability or to prior experience with color. This study investigated short-term color memory of 40 college students, 20 of whom were interior design…

Design and fabrication of structural color by local surface plasmonic meta-molecules

International Nuclear Information System (INIS)

Ma Ya-Qi; Shao Jin-Hai; Lu Bing-Rui; Zhang Si-Chao; Chen Yi-Fang; Zhang Ya-Feng; Sun Yan; Qu Xin-Ping

2015-01-01

In this paper, we propose a new form of nanostructures with Al film deposited on a patterned dielectric material for generating structural color, which is induced by local surface plasmonic resonant (LSPR) absorption in sub-wavelength-indented hole/ring arrays. Unlike other reported results obtained by using focus ion beam (FIB) to create metallic nanostructures, the nano-sized hole/ring arrays in Al film in this work are replicated by high resolution electron beam lithography (EBL) combined with self-aligned metallization. Clear structural color is observed and systematically studied by numerical simulations as well as optical characterizations. The central color is strongly related to the geometric size, which provides us with good opportunities to dye the colorless Al surface by controlling the hole/ring dimensions (both diameter and radius), and to open up broad applications in display, jewelry decoration, green production of packing papers, security code, and counterfeits prevention. (paper)

Improved linearity in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors with nonlinear polarization dielectric

Energy Technology Data Exchange (ETDEWEB)

Gao, Tao [Fundamental Science on EHF Laboratory, University of Electronic Science and Technology of China (UESTC), Chengdu 611731 (China); Science and Technology on Monolithic Integrated Circuits and Modules Laboratory, Nanjing Electronic Devices Institute, Nanjing 210016 (China); Xu, Ruimin [Fundamental Science on EHF Laboratory, University of Electronic Science and Technology of China (UESTC), Chengdu 611731 (China); Kong, Yuechan, E-mail: kycfly@163.com; Zhou, Jianjun; Kong, Cen; Dong, Xun; Chen, Tangsheng [Science and Technology on Monolithic Integrated Circuits and Modules Laboratory, Nanjing Electronic Devices Institute, Nanjing 210016 (China)

2015-06-15

We demonstrate highly improved linearity in a nonlinear ferroelectric of Pb(Zr{sub 0.52}Ti{sub 0.48})-gated AlGaN/GaN metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT). Distinct double-hump feature in the transconductance-gate voltage (g{sub m}-V{sub g}) curve is observed, yielding remarkable enhancement in gate voltage swing as compared to MIS-HEMT with conventional linear gate dielectric. By incorporating the ferroelectric polarization into a self-consistent calculation, it is disclosed that in addition to the common hump corresponding to the onset of electron accumulation, the second hump at high current level is originated from the nonlinear polar nature of ferroelectric, which enhances the gate capacitance by increasing equivalent dielectric constant nonlinearly. This work paves a way for design of high linearity GaN MIS-HEMT by exploiting the nonlinear properties of dielectric.

Colorism/Neo-Colorism

Science.gov (United States)

Snell, Joel

2017-01-01

There are numerous aspects to being non-Caucasian that may not be known by Whites. Persons of color suggest folks who are African, South Americans, Native Americans, Biracial, Asians and others. The question is what do these individuals feel relative to their color and facial characteristics. Eugene Robinson suggest that the future favorable color…

Color changes in pork in relation to high pressure treatment

DEFF Research Database (Denmark)

Bak, Kathrine Holmgaard

treatment and during a six-day storage period was investigated via surface reflectance. Spectroscopic studies (in the form of surface reflectance, UV-vis, and circular dichroism) on the effect of HP treatment on the soluble protein fraction of porcine LD were conducted attempting to explain the color......-denatured ferric myoglobin species was not similar to the heat-denatured pigment, ferrihemochrome, but instead a closely related species sharing features of denatured gobin, ferric iron, and brown color. The reversibility of the pressure-induced changes often observed for various myoglobin forms in solution were...

Color Histogram Diffusion for Image Enhancement

Science.gov (United States)

Kim, Taemin

2011-01-01

Various color histogram equalization (CHE) methods have been proposed to extend grayscale histogram equalization (GHE) for color images. In this paper a new method called histogram diffusion that extends the GHE method to arbitrary dimensions is proposed. Ranges in a histogram are specified as overlapping bars of uniform heights and variable widths which are proportional to their frequencies. This diagram is called the vistogram. As an alternative approach to GHE, the squared error of the vistogram from the uniform distribution is minimized. Each bar in the vistogram is approximated by a Gaussian function. Gaussian particles in the vistoram diffuse as a nonlinear autonomous system of ordinary differential equations. CHE results of color images showed that the approach is effective.

Designing the Color of Hot-Dip Galvanized Steel Sheet Through Destructive Light Interference Using a Zn-Ti Liquid Metallic Bath

Science.gov (United States)

Levai, Gabor; Godzsák, Melinda; Török, Tamas I.; Hakl, Jozsef; Takáts, Viktor; Csik, Attila; Vad, Kalman; Kaptay, George

2016-07-01

The color of hot-dip galvanized steel sheet was adjusted in a reproducible way using a liquid Zn-Ti metallic bath, air atmosphere, and controlling the bath temperature as the only experimental parameter. Coloring was found only for samples cooled in air and dipped into Ti-containing liquid Zn. For samples dipped into a 0.15 wt pct Ti-containing Zn bath, the color remained metallic (gray) below a 792 K (519 °C) bath temperature; it was yellow at 814 K ± 22 K (541 °C ± 22 °C), violet at 847 K ± 10 K (574 °C ± 10 °C), and blue at 873 K ± 15 K (600 °C ± 15 °C). With the increasing bath temperature, the thickness of the adhered Zn-Ti layer gradually decreased from 52 to 32 micrometers, while the thickness of the outer TiO2 layer gradually increased from 24 to 69 nm. Due to small Al contamination of the Zn bath, a thin (around 2 nm) alumina-rich layer is found between the outer TiO2 layer and the inner macroscopic Zn layer. It is proven that the color change was governed by the formation of thin outer TiO2 layer; different colors appear depending on the thickness of this layer, mostly due to the destructive interference of visible light on this transparent nano-layer. A complex model was built to explain the results using known relationships of chemical thermodynamics, adhesion, heat flow, kinetics of chemical reactions, diffusion, and optics. The complex model was able to reproduce the observations and allowed making predictions on the color of the hot-dip galvanized steel sample, as a function of the following experimental parameters: temperature and Ti content of the Zn bath, oxygen content, pressure, temperature and flow rate of the cooling gas, dimensions of the steel sheet, velocity of dipping the steel sheet into the Zn-Ti bath, residence time of the steel sheet within the bath, and the velocity of its removal from the bath. These relationships will be valuable for planning further experiments and technologies on color hot-dip galvanization of steel

Coloration of metallic and/or ceramic surfaces obtained by atomic layer deposited nano-coatings

Energy Technology Data Exchange (ETDEWEB)

Guzman, L., E-mail: luisg47@gmail.com [Fondazione Bruno Kessler (FBK), Centro Materiali e Microsistemi, Functional Materials & Photonic Structures Unit, via Sommarive 18, 38123 Trento (Italy); Vettoruzzo, F. [Ronda High Tech, via Vegri 83, 36010 Zane’, Vicenza (Italy); Laidani, N. [Fondazione Bruno Kessler (FBK), Centro Materiali e Microsistemi, Functional Materials & Photonic Structures Unit, via Sommarive 18, 38123 Trento (Italy)

2016-02-29

optically tested. • An ultrathin TiN (20 nm) top layer is able to confer intense blue color to metals.

Coloration of metallic and/or ceramic surfaces obtained by atomic layer deposited nano-coatings

International Nuclear Information System (INIS)

Guzman, L.; Vettoruzzo, F.; Laidani, N.

2016-01-01

ultrathin TiN (20 nm) top layer is able to confer intense blue color to metals.

A nanohole in a thin metal film as an efficient nonlinear optical element

Energy Technology Data Exchange (ETDEWEB)

Konstantinova, T. V.; Melent' ev, P. N.; Afanas' ev, A. E. [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation); Kuzin, A. A.; Starikov, P. A.; Baturin, A. S. [Moscow Institute of Physics and Technology (Russian Federation); Tausenev, A. V.; Konyashchenko, A. V. [OOO Avesta-proekt (Russian Federation); Balykin, V. I., E-mail: balykin@isan.tyroitsk.ru [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation)

2013-07-15

The nonlinear optical properties of single nanoholes and nanoslits fabricated in gold and aluminum nanofilms are studied by third harmonic generation (THG). It is shown that the extremely high third-order optical susceptibility of aluminum and the presence of strong plasmon resonance of a single nanohole in an aluminum film make possible an efficient nanolocalized radiation source at the third harmonic frequency. The THG efficiency for a single nanohole in a thin metal film can be close to unity for an exciting laser radiation intensity on the order of 10{sup 13} W/cm{sup 2}.

Nonlinear optical techniques for surface studies

International Nuclear Information System (INIS)

Shen, Y.R.

1981-09-01

Recent effort in developing nonlinear optical techniques for surface studies is reviewed. Emphasis is on monolayer detection of adsorbed molecules on surfaces. It is shown that surface coherent antiStokes Raman scattering (CARS) with picosecond pulses has the sensitivity of detecting submonolayer of molecules. On the other hand, second harmonic or sum-frequency generation is also sensitive enough to detect molecular monolayers. Surface-enhanced nonlinear optical effects on some rough metal surfaces have been observed. This facilitates the detection of molecular monolayers on such surfaces, and makes the study of molecular adsorption at a liquid-metal interface feasible. Advantages and disadvantages of the nonlinear optical techniques for surface studies are discussed

The Chemical States of Color-Induced Cations in Tourmaline Characterized by X-Ray Photoelectron Spectroscopy

Directory of Open Access Journals (Sweden)

Ming Li

2018-01-01

Full Text Available In order to better understand the effect of transition metal cations on color of tourmaline, X-ray photoelectron spectroscopy was used to investigate the species, chemical state, site occupancy, and chemical environment of color-induced metal cations in colorful tourmaline samples from Minas Gerais State, Brazil. Our results showed that the colorful tourmalines usually contained a small amount of transition metal elements, and a colorful tourmaline sample had several transition metal cations; however, the color of tourmaline resulted from the transition metal cations in the Y site of the crystal structure. The pink color of tourmaline was associated with Mn2+ in the Y site coordinating with F; the yellow color was derived from Ni2+ in the Y site binding to O; the green color was associated with Fe3+ in the Y site coordinating with O, OH, and F; the rose red color originated from Mn2+ and Ni2+ in the Y site in which Mn2+ coordinated with O and F, and Ni2+ coordinated with O; and the blue color was derived from Fe3+ and Mn2+ in the Y site in which Fe3+ binded to O, OH, and F and Mn2+ binded to F. Additionally, other transition metal cations were also observed in colorful tourmalines, but all these species occupied the Z site of the structure. In the pink and yellow samples, Fe and Cr were observed in Fe3+ and Cr3+; in the rose red sample, Fe was also found in Fe3+; in the blue sample, Cr was present in Cr3+; in the green sample, Mn, Ni, and Cu were found in Mn2+, Ni2+, and Cu2+, respectively. The color of tourmaline was induced from the absorption of the d-d transition of transition metals in the crystal structure, as charge transfer tended to occur between cations occupying different coordination positions.

Data-driven modeling of background and mine-related acidity and metals in river basins

Science.gov (United States)

Friedel, Michael J

2013-01-01

A novel application of self-organizing map (SOM) and multivariate statistical techniques is used to model the nonlinear interaction among basin mineral-resources, mining activity, and surface-water quality. First, the SOM is trained using sparse measurements from 228 sample sites in the Animas River Basin, Colorado. The model performance is validated by comparing stochastic predictions of basin-alteration assemblages and mining activity at 104 independent sites. The SOM correctly predicts (>98%) the predominant type of basin hydrothermal alteration and presence (or absence) of mining activity. Second, application of the Davies–Bouldin criteria to k-means clustering of SOM neurons identified ten unique environmental groups. Median statistics of these groups define a nonlinear water-quality response along the spatiotemporal hydrothermal alteration-mining gradient. These results reveal that it is possible to differentiate among the continuum between inputs of background and mine-related acidity and metals, and it provides a basis for future research and empirical model development.

Exchange Rate – Relative Price Nonlinear Cointegration Relationship in Malaysia

OpenAIRE

Venus Khim-Sen Liew; Chee-Keong Choong; Evan Lau; Kian-Ping Lim

2005-01-01

The finding of exchange rate–relative price nonlinear cointegration relationship in Malaysia, among others, suggests that nonlinear Purchasing Power Parity (PPP) equilibrium may be regarded as reference point in judging the short run misalignment of the Ringgit currency and thereby deducing effective policy actions. Moreover, economists who wish to extend the simple PPP exchange rate model into the more complicated monetary exchange models may do so comfortably, at least in the text of Malays...

Plasmonic nanospherical dimers for color pixels

KAUST Repository

Alrasheed, Salma

2018-04-20

Display technologies are evolving more toward higher resolution and miniaturization. Plasmonic color pixels can offer solutions to realize such technologies due to their sharp resonances and selective scattering and absorption at particular wavelengths. Metal nanosphere dimers are capable of supporting plasmon resonances that can be tuned to span the entire visible spectrum. In this article, we demonstrate numerically bright color pixels that are highly polarized and broadly tuned using periodic arrays of metal nanosphere dimers on a glass substrate. We show that it is possible to obtain RGB pixels in the reflection mode. The longitudinal plasmon resonance of nanosphere dimers along the axis of the dimer is the main contributor to the color of the pixel, while far-field diffractive coupling further enhances and tunes the plasmon resonance. The computational method used is the finite-difference time-domain method. The advantages of this approach include simplicity of the design, bright coloration, and highly polarized function. In addition, we show that it is possible to obtain different colors by varying the angle of incidence, the periodicity, the size of the dimer, the gap, and the substrate thickness.

Intersexual allometry differences and ontogenetic shifts of coloration patterns in two aquatic turtles, Graptemys oculifera and Graptemys flavimaculata

Science.gov (United States)

Ennen, Joshua R.; Lindeman, Peter V.; Lovich, Jeffrey E.

2015-01-01

Coloration can play critical roles in a species' biology. The allometry of color patterns may be useful for elucidating the evolutionary mechanisms responsible for shaping the traits. We measured characteristics relating to eight aspects of color patterns from Graptemys oculifera and G. flavimaculata to investigate the allometric differences among male, female, and unsexed juvenile specimens. Additionally, we investigated ontogenetic shifts by incorporating the unsexed juveniles into the male and female datasets. In general, male color traits were isometric (i.e., color scaled with body size), while females and juvenile color traits were hypoallometric, growing in size more slowly than the increase in body size. When we included unsexed juveniles in our male and female datasets, our linear regression analyses found all relationships to be hypoallometric and our model selection analysis found support for nonlinear models describing the relationship between body size and color patterns, suggestive of an ontogenetic shift in coloration traits for both sexes at maturity. Although color is critical for many species' biology and therefore under strong selective pressure in many other species, our results are likely explained by an epiphenomenon related to the different selection pressures on body size and growth rates between juveniles and adults and less attributable to the evolution of color patterns themselves.

Design and fabrication of structural color by local surface plasmonic meta-molecules

Science.gov (United States)

Ma, Ya-Qi; Shao, Jin-Hai; Zhang, Ya-Feng; Lu, Bing-Rui; Zhang, Si-Chao; Sun, Yan; Qu, Xin-Ping; Chen, Yi-Fang

2015-08-01

In this paper, we propose a new form of nanostructures with Al film deposited on a patterned dielectric material for generating structural color, which is induced by local surface plasmonic resonant (LSPR) absorption in sub-wavelength-indented hole/ring arrays. Unlike other reported results obtained by using focus ion beam (FIB) to create metallic nanostructures, the nano-sized hole/ring arrays in Al film in this work are replicated by high resolution electron beam lithography (EBL) combined with self-aligned metallization. Clear structural color is observed and systematically studied by numerical simulations as well as optical characterizations. The central color is strongly related to the geometric size, which provides us with good opportunities to dye the colorless Al surface by controlling the hole/ring dimensions (both diameter and radius), and to open up broad applications in display, jewelry decoration, green production of packing papers, security code, and counterfeits prevention. Project partially supported by the National Natural Science Foundation of China (Grant No. 61205148).

Nonlinear wave-mixing processes in the extreme ultraviolet

International Nuclear Information System (INIS)

Misoguti, L.; Christov, I. P.; Backus, S.; Murnane, M. M.; Kapteyn, H. C.

2005-01-01

We present data from two-color high-order harmonic generation in a hollow waveguide, that suggest the presence of a nonlinear-optical frequency conversion process driven by extreme ultraviolet light. By combining the fundamental and second harmonic of an 800 nm laser in a hollow-core fiber, with varying relative polarizations, and by observing the pressure and power scaling of the various harmonic orders, we show that the data are consistent with a picture where we drive the process of high-harmonic generation, which in turn drives four-wave frequency mixing processes in the extreme EUV. This work promises a method for extending nonlinear optics into the extreme ultraviolet region of the spectrum using an approach that has not previously been considered, and has compelling implications for generating tunable light at short wavelengths

Odderon in the color glass condensate

International Nuclear Information System (INIS)

Hatta, Y.; Iancu, E.; Itakura, K.; McLerran, L.

2005-01-01

We discuss the definition and the energy evolution of scattering amplitudes with C-odd ('odderon') quantum numbers within the effective theory for the color glass condensate (CGC) endowed with the functional, JIMWLK, evolution equation. We explicitly construct gauge-invariant amplitudes describing multiple odderon exchanges in the scattering between the CGC and two types of projectiles: a color-singlet quark-antiquark pair (or 'color dipole') and a system of three quarks in a colorless state. We deduce the energy evolution of these amplitudes from the general JIMWLK equation, which for this purpose is recast in a more synthetic form, which is manifestly infrared finite. For the dipole odderon, we confirm and extend the non-linear evolution equations recently proposed by Kovchegov, Szymanowski and Wallon, which couple the evolution of the odderon to that of the pomeron, and predict the rapid suppression of the odderon exchanges in the saturation regime at high energy. For the 3-quark system, we focus on the linear regime at relatively low energy, where our general equations are shown to reduce to the Bartels-Kwiecinski-Praszalowicz equation. Our gauge-invariant amplitudes, and the associated evolution equations, stay explicitly outside the Moebius representation, which is the Hilbert space where the BFKL Hamiltonian exhibits holomorphic separability

Odderon in the color glass condensate

Science.gov (United States)

Hatta, Y.; Iancu, E.; Itakura, K.; McLerran, L.

2005-10-01

We discuss the definition and the energy evolution of scattering amplitudes with C-odd ("odderon") quantum numbers within the effective theory for the color glass condensate (CGC) endowed with the functional, JIMWLK, evolution equation. We explicitly construct gauge-invariant amplitudes describing multiple odderon exchanges in the scattering between the CGC and two types of projectiles: a color-singlet quark-antiquark pair (or 'color dipole') and a system of three quarks in a colorless state. We deduce the energy evolution of these amplitudes from the general JIMWLK equation, which for this purpose is recast in a more synthetic form, which is manifestly infrared finite. For the dipole odderon, we confirm and extend the non-linear evolution equations recently proposed by Kovchegov, Szymanowski and Wallon, which couple the evolution of the odderon to that of the pomeron, and predict the rapid suppression of the odderon exchanges in the saturation regime at high energy. For the 3-quark system, we focus on the linear regime at relatively low energy, where our general equations are shown to reduce to the Bartels-Kwiecinski-Praszalowicz equation. Our gauge-invariant amplitudes, and the associated evolution equations, stay explicitly outside the Möbius representation, which is the Hilbert space where the BFKL Hamiltonian exhibits holomorphic separability.

Odderon in the color glass condensate

Energy Technology Data Exchange (ETDEWEB)

Hatta, Y. [RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973 (United States); Iancu, E. [Service de Physique Theorique, CEA Saclay, 91191 Gif-sur-Yvette (France)]. E-mail: iancu@spht.saclay.cea.fr; Itakura, K. [Service de Physique Theorique, CEA Saclay, 91191 Gif-sur-Yvette (France); McLerran, L. [Physics Department and RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973 (United States)

2005-10-03

We discuss the definition and the energy evolution of scattering amplitudes with C-odd ('odderon') quantum numbers within the effective theory for the color glass condensate (CGC) endowed with the functional, JIMWLK, evolution equation. We explicitly construct gauge-invariant amplitudes describing multiple odderon exchanges in the scattering between the CGC and two types of projectiles: a color-singlet quark-antiquark pair (or 'color dipole') and a system of three quarks in a colorless state. We deduce the energy evolution of these amplitudes from the general JIMWLK equation, which for this purpose is recast in a more synthetic form, which is manifestly infrared finite. For the dipole odderon, we confirm and extend the non-linear evolution equations recently proposed by Kovchegov, Szymanowski and Wallon, which couple the evolution of the odderon to that of the pomeron, and predict the rapid suppression of the odderon exchanges in the saturation regime at high energy. For the 3-quark system, we focus on the linear regime at relatively low energy, where our general equations are shown to reduce to the Bartels-Kwiecinski-Praszalowicz equation. Our gauge-invariant amplitudes, and the associated evolution equations, stay explicitly outside the Moebius representation, which is the Hilbert space where the BFKL Hamiltonian exhibits holomorphic separability.

FY 1999 project on the development of new industry support type international standards. Standardization of color management; 1999 nendo shinki sangyo shiengata kokusai hyojun kaihatsu jigyo seika hokokusho. Iro saigen kanri (color management) no hyojunka

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

For the purpose of eliminating variations in color reproduction in multi-media output devices, study was conducted of making a standard plan for color information equipment as hardware and for the software to determine the characteristics, and the FY 1999 results were summarized. As to the standardization of color control in input/output devices, characteristic dependency of color printer under environmental conditions such as ambient temperature/humidity was determined. And to integrate it into the ICC profile, the profile was expanded. Concerning the standardization of multi-spectrum color image description format, non-linear spectral characteristics were investigated which are dependent on types of light sources, light intensity and geometric conditions. In relation to the standardization of psychological color reproduction, the scope of the experiment using examinee was expanded, and the study was so conducted that the standard image for skin color evaluation use can be recognized as the one that has statistical accuracy. A sequence method which is more simple and more effective was established. In the discussions of the proposed international standards, studies were carried out of the electronic still camera color characteristics measurement and the color space ISO RGB. (NEDO)

Relative SHG measurements of metal thin films: Gold, silver, aluminum, cobalt, chromium, germanium, nickel, antimony, titanium, titanium nitride, tungsten, zinc, silicon and indium tin oxide

Directory of Open Access Journals (Sweden)

Franklin Che

Full Text Available We have experimentally measured the surface second-harmonic generation (SHG of sputtered gold, silver, aluminum, zinc, tungsten, copper, titanium, cobalt, nickel, chromium, germanium, antimony, titanium nitride, silicon and indium tin oxide thin films. The second-harmonic response was measured in reflection using a 150 fs p-polarized laser pulse at 1561 nm. We present a clear comparison of the SHG intensity of these films relative to each other. Our measured relative intensities compare favorably with the relative intensities of metals with published data. We also report for the first time to our knowledge the surface SHG intensity of tungsten and antimony relative to that of well known metallic thin films such as gold and silver. Keywords: Surface second-harmonic generation, Nonlinear optics, Metal thin films

Possible relationship between metal abundance and luminosity for disk galaxies

International Nuclear Information System (INIS)

Bothun, G.D.; Romanishin, W.; Strom, S.E.; Strom, K.M.

1984-01-01

Near-infrared colors have been measured for a sample of 31 late-type galaxies in the Pegasus I and Pisces clusters; system luminosities in the sample cover the range -19< M/sub H/<-23.5. The color index (J-K) correlates strongly with the absolute H magnitude; lower-luminosity systems have bluer colors. These observations are consistent with the assumption that the mean metal abundance of the old disk population decreases systematically with luminosity. The systematic variation of (B-H) with absolute H magnitude reported recently by Tully et al. derives in part from this proposed systematic change of metallicity with luminosity. However, one must still posit a relative increase in the number of newly formed stars and/or a systematic smaller age for lower-luminosity disks in order to fully explain the observed (B-H), H relation

[The use of computer-aided colorimeter in porcelain-fused-to-metal (PFM) crowns among patients with special colored teeth].

Science.gov (United States)

Fu, Yuan-fei; Weng, Wei-min

2004-02-01

To evaluate the roll of ShadeEye-NCC, a computer-aided colorimeter, in Porcelain-Fused-to-Metal crowns among patients with special colored Teeth. The first step was to choose the proper patients. The next was to use the colorimeter to measure the base shade of tooth and fabricate the PFM crowns according to the recipe given by the colorimeter. At last, the effects of the PFM crowns were evaluated subjectively by patients and doctor. The satisfaction rates of patients and doctor were 83.7% and 81.4% respectively, there was no significant difference between the two rates. The computer-aided colorimeter can offer good base shade recipe for fabricating PFM crowns of patients with special colored teeth.

Enhancement of nonlinear optical properties of compounds of silica

Indian Academy of Sciences (India)

The aim of this paper is to introduce a method for enhancing the nonlinear optical properties in silica glass by using metallic nanoparticles. First, the T-matrix method is developed to calculate the effective dielectric constant for the compound of silica glass and metallic nanoparticles, both of which possess nonlinear dielectric ...

Performance of metal compound on thermolysis and electrolysis on sugar industries waste water treatment: COD and color removal with sludge analysis (batch-experiment)

Science.gov (United States)

Sahu, Omprakash

2017-10-01

The sugar cane industry is one of the most water demanding industries. Sugar industries consume and generate excess amount of water. The generated water contains organic compounds, which would cause pollution. The aim of this research work is to study the effectiveness of metal compound for treatment of sugar industry waste water by thermolysis and electrolysis process. The result shows ferrous metal catalyst shows 80 and 85 % chemical oxygen demand and color removal at pH 6, optimum mass loading 4 kg/m3, treatment temperature 85 °C and treatment time 9 h. When ferrous material was used as electrode, maximum 81 % chemical oxygen demand and 84 % color removal at pH 6, current density 156 Am-2, treatment time 120 min and anode consumption 0.7 g for 1.5 L wastewater were obtained.

Memory for color reactivates color processing region.

Science.gov (United States)

Slotnick, Scott D

2009-11-25

Memory is thought to be constructive in nature, where features processed in different cortical regions are synthesized during retrieval. In an effort to support this constructive memory framework, the present functional magnetic resonance imaging study assessed whether memory for color reactivated color processing regions. During encoding, participants were presented with colored and gray abstract shapes. During retrieval, old and new shapes were presented in gray and participants responded 'old-colored', 'old-gray', or 'new'. Within color perception regions, color memory related activity was observed in the left fusiform gyrus, adjacent to the collateral sulcus. A retinotopic mapping analysis indicated this activity occurred within color processing region V8. The present feature specific evidence provides compelling support for a constructive view of memory.

Experimental verification of the intrinsic ultrafast delayed nonlinearity of gold

DEFF Research Database (Denmark)

Bache, Morten; Lysenko, Oleg; Olivier, Nicolas

2017-01-01

Surface plasmon polaritons (SPPs) in plasmonic metal waveguides can excite a third-order nonlinear response [1] much akin the well-known self-phase modulation (SPM) and two-photon absorption seen in light propagating in dielectric waveguides. In metals, the nonlinearity mainly arises as a self...

The universal relation of galactic chemical evolution: the origin of the mass-metallicity relation

International Nuclear Information System (INIS)

Zahid, H. Jabran; Dima, Gabriel I.; Kudritzki, Rolf-Peter; Kewley, Lisa J.; Geller, Margaret J.; Hwang, Ho Seong; Silverman, John D.; Kashino, Daichi

2014-01-01

We examine the mass-metallicity relation for z ≲ 1.6. The mass-metallicity relation follows a steep slope with a turnover, or 'knee', at stellar masses around 10 10 M ☉ . At stellar masses higher than the characteristic turnover mass, the mass-metallicity relation flattens as metallicities begin to saturate. We show that the redshift evolution of the mass-metallicity relation depends only on the evolution of the characteristic turnover mass. The relationship between metallicity and the stellar mass normalized to the characteristic turnover mass is independent of redshift. We find that the redshift-independent slope of the mass-metallicity relation is set by the slope of the relationship between gas mass and stellar mass. The turnover in the mass-metallicity relation occurs when the gas-phase oxygen abundance is high enough that the amount of oxygen locked up in low-mass stars is an appreciable fraction of the amount of oxygen produced by massive stars. The characteristic turnover mass is the stellar mass, where the stellar-to-gas mass ratio is unity. Numerical modeling suggests that the relationship between metallicity and the stellar-to-gas mass ratio is a redshift-independent, universal relationship followed by all galaxies as they evolve. The mass-metallicity relation originates from this more fundamental universal relationship between metallicity and the stellar-to-gas mass ratio. We test the validity of this universal metallicity relation in local galaxies where stellar mass, metallicity, and gas mass measurements are available. The data are consistent with a universal metallicity relation. We derive an equation for estimating the hydrogen gas mass from measurements of stellar mass and metallicity valid for z ≲ 1.6 and predict the cosmological evolution of galactic gas masses.

Variability of Extragalactic Objects in Relation to Redshift, Color ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

properties of the objects, viz., redshift, color indices, radio spectral index ... properties of different types of closely related objects are expected to throw light on the ...... z = 3.0, OVV objects are concentrated at the lower range of the scale, mostly at ..... from the practical point of view in the sense that redshifts can be predicted ...

THE SYNTHETIC-OVERSAMPLING METHOD: USING PHOTOMETRIC COLORS TO DISCOVER EXTREMELY METAL-POOR STARS

Energy Technology Data Exchange (ETDEWEB)

Miller, A. A., E-mail: amiller@astro.caltech.edu [Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 169-506, Pasadena, CA 91109 (United States)

2015-09-20

Extremely metal-poor (EMP) stars ([Fe/H] ≤ −3.0 dex) provide a unique window into understanding the first generation of stars and early chemical enrichment of the universe. EMP stars are exceptionally rare, however, and the relatively small number of confirmed discoveries limits our ability to exploit these near-field probes of the first ∼500 Myr after the Big Bang. Here, a new method to photometrically estimate [Fe/H] from only broadband photometric colors is presented. I show that the method, which utilizes machine-learning algorithms and a training set of ∼170,000 stars with spectroscopically measured [Fe/H], produces a typical scatter of ∼0.29 dex. This performance is similar to what is achievable via low-resolution spectroscopy, and outperforms other photometric techniques, while also being more general. I further show that a slight alteration to the model, wherein synthetic EMP stars are added to the training set, yields the robust identification of EMP candidates. In particular, this synthetic-oversampling method recovers ∼20% of the EMP stars in the training set, at a precision of ∼0.05. Furthermore, ∼65% of the false positives from the model are very metal-poor stars ([Fe/H] ≤ −2.0 dex). The synthetic-oversampling method is biased toward the discovery of warm (∼F-type) stars, a consequence of the targeting bias from the Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding survey. This EMP selection method represents a significant improvement over alternative broadband optical selection techniques. The models are applied to >12 million stars, with an expected yield of ∼600 new EMP stars, which promises to open new avenues for exploring the early universe.

Nonlinear phenomena in the highly excited state of C60

International Nuclear Information System (INIS)

Byrne, H.J.; Maser, W.K.; Kaiser, M.; Akselrod, L.; Anders, J.; Ruehle, W.W.; Zhou, X.Q.; Mittelbach, A.; Roth, S.

1993-01-01

Under high intensity illumination, the optical and electronic properties of fullerenes are seen to undergo dramatic, nonlinear changes. The photoluminescence emission is seen to increase with approximately the third power of the input intensity above an apparent threshold intensity. Associated with this nonlinear increase is the emergence of a long lifetime emission component and a redshifting of the emission spectrum. Above the threshold intensity the photoconductive response increases with approximately the cube of the input power. In the highly excited state, the photoconductive response becomes relatively temperature independent compared to the thermally activated behaviour observed at low intensities. The characteristics of the temperature dependence are associated with a metallic-like phase in the highly excited state and therefore an optically driven insulator to metal transition is proposed as a description of the observed phenomena. (orig.)

Full-color tuning in binary polymer:perovskite nanocrystals organic-inorganic hybrid blends

Science.gov (United States)

Perulli, A.; Balena, A.; Fernandez, M.; Nedelcu, G.; Cretí, A.; Kovalenko, M. V.; Lomascolo, M.; Anni, M.

2018-04-01

The excellent optical and electronic properties of metal halide perovskites recently proposed these materials as interesting active materials for optoelectronic applications. In particular, the high color purity of perovskite colloidal nanocrystals (NCs) had recently motivated their exploration as active materials for light emitting diodes with tunable emission across the visible range. In this work, we investigated the emission properties of binary blends of conjugated polymers and perovskite NCs. We demonstrate that the emission color of the blends is determined by the superposition of the component photoluminescence spectra, allowing color tuning by acting on the blend relative composition. The use of two different polymers, two different perovskite NCs, and different blend compositions is exploited to tune the blend color in the blue-green, yellow-red, and blue-red ranges, including white light generation.

A suggested color scheme for reducing perception-related accidents on construction work sites.

Science.gov (United States)

Yi, June-seong; Kim, Yong-woo; Kim, Ki-aeng; Koo, Bonsang

2012-09-01

Changes in workforce demographics have led to the need for more sophisticated approaches to addressing the safety requirements of the construction industry. Despite extensive research in other industry domains, the construction industry has been passive in exploring the impact of a color scheme; perception-related accidents have been effectively diminished by its implementation. The research demonstrated that the use of appropriate color schemes could improve the actions and psychology of workers on site, thereby increasing their perceptions of potentially dangerous situations. As a preliminary study, the objects selected by rigorous analysis on accident reports were workwear, safety net, gondola, scaffolding, and safety passage. The colors modified on site for temporary facilities were adopted from existing theoretical and empirical research that suggests the use of certain colors and their combinations to improve visibility and conspicuity while minimizing work fatigue. The color schemes were also tested and confirmed through two workshops with workers and managers currently involved in actual projects. The impacts of color schemes suggested in this paper are summarized as follows. First, the color schemes improve the conspicuity of facilities with other on site components, enabling workers to quickly discern and orient themselves in their work environment. Secondly, the color schemes have been selected to minimize the visual work fatigue and monotony that can potentially increase accidents. Copyright © 2011 Elsevier Ltd. All rights reserved.

Non-linear, connectivity and threshold-dominated runoff-generation controls DOC and heavy metal export in a small peat catchment

Science.gov (United States)

Birkel, Christian; Broder, Tanja; Biester, Harald

2017-04-01

Peat soils act as important carbon sinks, but they also release large amounts of dissolved organic carbon (DOC) to the aquatic system. The DOC export is strongly tied to the export of soluble heavy metals. The accumulation of potentially toxic substances due to anthropogenic activities, and their natural export from peat soils to the aquatic system is an important health and environmental issue. However, limited knowledge exists as to how much of these substances are mobilized, how they are mobilized in terms of flow pathways and under which hydrometeorological conditions. In this study, we report from a combined experimental and modelling effort to provide greater process understanding from a small, lead (Pb) and arsenic (As) contaminated upland peat catchment in northwestern Germany. We developed a minimally parameterized, but process-based, coupled hydrology-biogeochemistry model applied to simulate detailed hydrometric and biogeochemical data. The model was based on an initial data mining analysis, in combination with regression relationships of discharge, DOC and element export. We assessed the internal model DOC-processing based on stream-DOC hysteresis patterns and 3-hourly time step groundwater level and soil DOC data (not used for calibration as an independent model test) for two consecutive summer periods in 2013 and 2014. We found that Pb and As mobilization can be efficiently predicted from DOC transport alone, but Pb showed a significant non-linear relationship with DOC, while As was linearly related to DOC. The relatively parsimonious model (nine calibrated parameters in total) showed the importance of non-linear and rapid near-surface runoff-generation mechanisms that caused around 60% of simulated DOC load. The total load was high even though these pathways were only activated during storm events on average 30% of the monitoring time - as also shown by the experimental data. Overall, the drier period 2013 resulted in increased nonlinearity, but

A Modified Conjugacy Condition and Related Nonlinear Conjugate Gradient Method

Directory of Open Access Journals (Sweden)

Shengwei Yao

2014-01-01

Full Text Available The conjugate gradient (CG method has played a special role in solving large-scale nonlinear optimization problems due to the simplicity of their very low memory requirements. In this paper, we propose a new conjugacy condition which is similar to Dai-Liao (2001. Based on this condition, the related nonlinear conjugate gradient method is given. With some mild conditions, the given method is globally convergent under the strong Wolfe-Powell line search for general functions. The numerical experiments show that the proposed method is very robust and efficient.

Relation between nonlinear models and gauge ambiguities

International Nuclear Information System (INIS)

Balachandran, A.P.; Ramachandran, R.; Rupertsberger, H.; Skagerstam, B.S.

1980-01-01

We show that the solutions of a class of nonlinear models also generate gauge ambiguities in the vacuum sector of Yang-Mills theories. Our results extend known connections between gauge ambiguities and certain nonlinear sigma-models, and clarify the underlying group theory. For many nonlinear models, we also give a simple, intrinsic parametrization of physical fields (which have values in a homogeneous space of a group). (orig.)

Extragalactic globular clusters. I. The metallicity calibration

International Nuclear Information System (INIS)

Brodie, J.P.; Huchra, J.P.

1990-01-01

The ability of absorption-line strength indices, measured from integrated globular cluster spectra, to predict mean cluster metallicity is explored. Statistical criteria, are used to identify the six best indices out of about 20 measured in a large sample of Galactic and M31 cluster spectra. Linear relations between index and metallicity have been derived along with new calibrations of infrared colors (V - K, J - K, and CO) versus Fe/H. Estimates of metallicity from the six spectroscopic index-metallicity relations have been combined in three different ways to identify the most efficient estimator and the minimum bias estimator of Fe/H - the weighted mean. This provides an estimate of Fe/H accurate to about 15 percent. 37 refs

Investigating Relational Aggression and Bullying for Girls' of Color in Oklahoma: A Phenomenological Study

Science.gov (United States)

Flynn, Gayle L.

2016-01-01

This qualitative research study, applying aspects of van Manen's framework for hermeneutic phenomenological research, was conducted to investigate the narratives of relationally aggressive girls of color. The study focused on nine adolescent girls of color who were ages 14-17 years old and exhibited aggressive/bullying behaviors representing the…

Sensory Drive, Color, and Color Vision.

Science.gov (United States)

Price, Trevor D

2017-08-01

Colors often appear to differ in arbitrary ways among related species. However, a fraction of color diversity may be explained because some signals are more easily perceived in one environment rather than another. Models show that not only signals but also the perception of signals should regularly evolve in response to different environments, whether these primarily involve detection of conspecifics or detection of predators and prey. Thus, a deeper understanding of how perception of color correlates with environmental attributes should help generate more predictive models of color divergence. Here, I briefly review our understanding of color vision in vertebrates. Then I focus on opsin spectral tuning and opsin expression, two traits involved in color perception that have become amenable to study. I ask how opsin tuning is correlated with ecological differences, notably the light environment, and how this potentially affects perception of conspecific colors. Although opsin tuning appears to evolve slowly, opsin expression levels are more evolutionarily labile but have been difficult to connect to color perception. The challenge going forward will be to identify how physiological differences involved in color vision, such as opsin expression levels, translate into perceptual differences, the selection pressures that have driven those differences, and ultimately how this may drive evolution of conspecific colors.

Fluctuations in Nonlinear Systems: A Short Review

International Nuclear Information System (INIS)

Rubia, F.J. de la; Buceta, J.; Cabrera, J.L.; Olarrea, J.; Parrondo, J.M.R.

2003-01-01

We review some results that illustrate the constructive role of noise in nonlinear systems. Several phenomena are briefly discussed: optimal localization of orbits in a system with limit cycle behavior and perturbed by colored noise; stochastic branch selection at secondary bifurcations; noise- induced order/disorder transitions and pattern formation in spatially extended systems. In all cases the presence of noise is crucial, and the results reinforce the modern view of the importance of noise in the evolution of nonlinear systems. (author)

Design and optimization of color lookup tables on a simplex topology.

Science.gov (United States)

Monga, Vishal; Bala, Raja; Mo, Xuan

2012-04-01

An important computational problem in color imaging is the design of color transforms that map color between devices or from a device-dependent space (e.g., RGB/CMYK) to a device-independent space (e.g., CIELAB) and vice versa. Real-time processing constraints entail that such nonlinear color transforms be implemented using multidimensional lookup tables (LUTs). Furthermore, relatively sparse LUTs (with efficient interpolation) are employed in practice because of storage and memory constraints. This paper presents a principled design methodology rooted in constrained convex optimization to design color LUTs on a simplex topology. The use of n simplexes, i.e., simplexes in n dimensions, as opposed to traditional lattices, recently has been of great interest in color LUT design for simplex topologies that allow both more analytically tractable formulations and greater efficiency in the LUT. In this framework of n-simplex interpolation, our central contribution is to develop an elegant iterative algorithm that jointly optimizes the placement of nodes of the color LUT and the output values at those nodes to minimize interpolation error in an expected sense. This is in contrast to existing work, which exclusively designs either node locations or the output values. We also develop new analytical results for the problem of node location optimization, which reduces to constrained optimization of a large but sparse interpolation matrix in our framework. We evaluate our n -simplex color LUTs against the state-of-the-art lattice (e.g., International Color Consortium profiles) and simplex-based techniques for approximating two representative multidimensional color transforms that characterize a CMYK xerographic printer and an RGB scanner, respectively. The results show that color LUTs designed on simplexes offer very significant benefits over traditional lattice-based alternatives in improving color transform accuracy even with a much smaller number of nodes.

Simple approach to three-color two-photon microscopy by a fiber-optic wavelength convertor.

Science.gov (United States)

Li, Kuen-Che; Huang, Lynn L H; Liang, Jhih-Hao; Chan, Ming-Che

2016-11-01

A simple approach to multi-color two-photon microscopy of the red, green, and blue fluorescent indicators was reported based on an ultra-compact 1.03-μm femtosecond laser and a nonlinear fiber. Inside the nonlinear fiber, the 1.03-μm laser pulses were simultaneously blue-shifted to 0.6~0.8 μm and red-shifted to 1.2~1.4 μm region by the Cherenkov radiation and fiber Raman gain effects. The wavelength-shifted 0.6~0.8 μm and 1.2~1.4 μm radiations were co-propagated with the residual non-converted 1.03-μm pulses inside the same nonlinear fiber to form a fiber-output three-color femtosecond source. The application of the multi-wavelength sources on multi-color two-photon fluorescence microscopy were also demonstrated. Overall, due to simple system configuration, convenient wavelength conversion, easy wavelength tunability within the entire 0.7~1.35 μm bio-penetration window and less requirement for high power and bulky light sources, the simple approach to multi-color two-photon microscopy could be widely applicable as an easily implemented and excellent research tool for future biomedical and possibly even clinical applications.

KLT-type relations for QCD and bicolor amplitudes from color-factor symmetry

Science.gov (United States)

Brown, Robert W.; Naculich, Stephen G.

2018-03-01

Color-factor symmetry is used to derive a KLT-type relation for tree-level QCD amplitudes containing gluons and an arbitrary number of massive or massless quark-antiquark pairs, generalizing the expression for Yang-Mills amplitudes originally postulated by Bern, De Freitas, and Wong. An explicit expression is given for all amplitudes with two or fewer quark-antiquark pairs in terms of the (modified) momentum kernel. We also introduce the bicolor scalar theory, the "zeroth copy" of QCD, containing massless biadjoint scalars and massive bifundamental scalars, generalizing the biadjoint scalar theory of Cachazo, He, and Yuan. We derive KLT-type relations for tree-level amplitudes of biadjoint and bicolor theories using the color-factor symmetry possessed by these theories.

Optimum color filters for CCD digital cameras

Science.gov (United States)

Engelhardt, Kai; Kunz, Rino E.; Seitz, Peter; Brunner, Harald; Knop, Karl

1993-12-01

As part of the ESPRIT II project No. 2103 (MASCOT) a high performance prototype color CCD still video camera was developed. Intended for professional usage such as in the graphic arts, the camera provides a maximum resolution of 3k X 3k full color pixels. A high colorimetric performance was achieved through specially designed dielectric filters and optimized matrixing. The color transformation was obtained by computer simulation of the camera system and non-linear optimization which minimized the perceivable color errors as measured in the 1976 CIELUV uniform color space for a set of about 200 carefully selected test colors. The color filters were designed to allow perfect colorimetric reproduction in principle and at the same time with imperceptible color noise and with special attention to fabrication tolerances. The camera system includes a special real-time digital color processor which carries out the color transformation. The transformation can be selected from a set of sixteen matrices optimized for different illuminants and output devices. Because the actual filter design was based on slightly incorrect data the prototype camera showed a mean colorimetric error of 2.7 j.n.d. (CIELUV) in experiments. Using correct input data in the redesign of the filters, a mean colorimetric error of only 1 j.n.d. (CIELUV) seems to be feasible, implying that it is possible with such an optimized color camera to achieve such a high colorimetric performance that the reproduced colors in an image cannot be distinguished from the original colors in a scene, even in direct comparison.

Using Single Colors and Color Pairs to Communicate Basic Tastes II: Foreground-Background Color Combinations.

Science.gov (United States)

Woods, Andy T; Marmolejo-Ramos, Fernando; Velasco, Carlos; Spence, Charles

2016-01-01

People associate basic tastes (e.g., sweet, sour, bitter, and salty) with specific colors (e.g., pink or red, green or yellow, black or purple, and white or blue). In the present study, we investigated whether a color bordered by another color (either the same or different) would give rise to stronger taste associations relative to a single patch of color. We replicate previous findings, highlighting the existence of a robust crossmodal correspondence between individual colors and basic tastes. On occasion, color pairs were found to communicate taste expectations more consistently than were single color patches. Furthermore, and in contrast to a recent study in which the color pairs were shown side-by-side, participants took no longer to match the color pairs with tastes than the single colors (they had taken twice as long to respond to the color pairs in the previous study). Possible reasons for these results are discussed, and potential applications for the results, and for the testing methodology developed, are outlined.

Non-linear gauge transformations in D=10 SYM theory and the BCJ duality

Energy Technology Data Exchange (ETDEWEB)

Lee, Seungjin [Max-Planck-Institut für Gravitationsphysik Albert-Einstein-Institut,14476 Potsdam (Germany); Mafra, Carlos R. [Institute for Advanced Study, School of Natural Sciences,Einstein Drive, Princeton, NJ 08540 (United States); DAMTP, University of Cambridge,Wilberforce Road, Cambridge, CB3 0WA (United Kingdom); Schlotterer, Oliver [Max-Planck-Institut für Gravitationsphysik Albert-Einstein-Institut,14476 Potsdam (Germany)

2016-03-14

Recent progress on scattering amplitudes in super Yang-Mills and superstring theory benefitted from the use of multiparticle superfields. They universally capture tree-level subdiagrams, and their generating series solve the non-linear equations of ten-dimensional super Yang-Mills. We provide simplified recursions for multiparticle superfields and relate them to earlier representations through non-linear gauge transformations of their generating series. Moreover, we discuss the gauge transformations which enforce their Lie symmetries as suggested by the Bern-Carrasco-Johansson duality between color and kinematics. Another gauge transformation due to Harnad and Shnider is shown to streamline the theta-expansion of multiparticle superfields, bypassing the need to use their recursion relations beyond the lowest components. The findings of this work tremendously simplify the component extraction from kinematic factors in pure spinor superspace.

Measuring metallicities with Hubble space telescope/wide-field camera 3 photometry

Energy Technology Data Exchange (ETDEWEB)

Ross, Teresa L.; Holtzman, Jon A. [Department of Astronomy, New Mexico State University, P.O. Box 30001, MSC 4500, Las Cruces, NM 88003-8001 (United States); Anthony-Twarog, Barbara J.; Twarog, Bruce [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045-7582 (United States); Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Saha, Abhijit [National Optical Astronomy Observatory, P.O. Box 26732, Tucson, AZ 85726 (United States); Walker, Alistair, E-mail: rosst@nmsu.edu, E-mail: holtz@nmsu.edu, E-mail: bjat@ku.edu, E-mail: btwarog@ku.edu, E-mail: heb11@psu.edu, E-mail: awalker@ctio.noao.edu [Cerro Tololo Inter-American Observatory (CTIO), National Optical Astronomy Observatory, Casilla 603, La Serena (Chile)

2014-01-01

We quantified and calibrated the metallicity and temperature sensitivities of colors derived from nine Wide-Field Camera 3 filters on board the Hubble Space Telescope using Dartmouth isochrones and Kurucz atmosphere models. The theoretical isochrone colors were tested and calibrated against observations of five well studied galactic clusters, M92, NGC 6752, NGC 104, NGC 5927, and NGC 6791, all of which have spectroscopically determined metallicities spanning –2.30 < [Fe/H] <+0.4. We found empirical corrections to the Dartmouth isochrone grid for each of the following color-magnitude diagrams (CMDs): (F555W-F814W, F814W), (F336W-F555W, F814W), (F390M-F555W, F814W), and (F390W-F555W, F814W). Using empirical corrections, we tested the accuracy and spread of the photometric metallicities assigned from CMDs and color-color diagrams (which are necessary to break the age-metallicity degeneracy). Testing three color-color diagrams [(F336W-F555W),(F390M-F555W),(F390W-F555W), versus (F555W-F814W)], we found the colors (F390M-F555W) and (F390W-F555W) to be the best suited to measure photometric metallicities. The color (F390W-F555W) requires much less integration time, but generally produces wider metallicity distributions and, at very low metallicity, the metallicity distribution function (MDF) from (F390W-F555W) is ∼60% wider than that from (F390M-F555W). Using the calibrated isochrones, we recovered the overall cluster metallicity to within ∼0.1 dex in [Fe/H] when using CMDs (i.e., when the distance, reddening, and ages are approximately known). The measured MDF from color-color diagrams shows that this method measures metallicities of stellar clusters of unknown age and metallicity with an accuracy of ∼0.2-0.5 dex using F336W-F555W, ∼0.15-0.25 dex using F390M-F555W, and ∼0.2-0.4 dex with F390W-F555W, with the larger uncertainty pertaining to the lowest metallicity range.

Precision of synesthetic color matching resembles that for recollected colors rather than physical colors.

Science.gov (United States)

Arnold, Derek H; Wegener, Signy V; Brown, Francesca; Mattingley, Jason B

2012-10-01

Grapheme-color synesthesia is an atypical condition in which individuals experience sensations of color when reading printed graphemes such as letters and digits. For some grapheme-color synesthetes, seeing a printed grapheme triggers a sensation of color, but hearing the name of a grapheme does not. This dissociation allowed us to compare the precision with which synesthetes are able to match their color experiences triggered by visible graphemes, with the precision of their matches for recalled colors based on the same graphemes spoken aloud. In six synesthetes, color matching for printed graphemes was equally variable relative to recalled experiences. In a control experiment, synesthetes and age-matched controls either matched the color of a circular patch while it was visible on a screen, or they judged its color from memory after it had disappeared. Both synesthetes and controls were more variable when matching from memory, and the variance of synesthetes' recalled color judgments matched that associated with their synesthetic judgments for visible graphemes in the first experiment. Results suggest that synesthetic experiences of color triggered by achromatic graphemes are analogous to recollections of color.

HIV-related ocular microangiopathic syndrome and color contrast sensitivity.

Science.gov (United States)

Geier, S A; Hammel, G; Bogner, J R; Kronawitter, U; Berninger, T; Goebel, F D

1994-06-01

Color vision deficits in patients with acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus (HIV) disease were reported, and a retinal pathogenic mechanism was proposed. The purpose of this study was to evaluate the association of color vision deficits with HIV-related retinal microangiopathy. A computer graphics system was used to measure protan, deutan, and tritan color contrast sensitivity (CCS) thresholds in 60 HIV-infected patients. Retinal microangiopathy was measured by counting the number of cotton-wool spots, and conjunctival blood-flow sludging was determined. Additional predictors were CD4+ count, age, time on aerosolized pentamidine, time on zidovudine, and Walter Reed staging. The relative influence of each predictor was calculated by stepwise multiple regression analysis (inclusion criterion; incremental P value = < 0.05) using data for the right eyes (RE). The results were validated by using data for the left eyes (LE) and both eyes (BE). The only included predictors in multiple regression analyses for the RE were number of cotton-wool spots (tritan: R = .70; deutan: R = .46; and protan: R = .58; P < .0001 for all axes) and age (tritan: increment of R [Ri] = .05, P = .002; deutan: Ri = .10, P = .004; and protan: Ri = .05, P = .002). The predictors time on zidovudine (Ri = .05, P = .002) and Walter Reed staging (Ri = .03, P = .01) were additionally included in multiple regression analysis for tritan LE. The results for deutan LE were comparable to those for the RE. In the analysis for protan LE, the only included predictor was number of cotton-wool spots. In the analyses for BE, no further predictors were included. The predictors Walter Reed staging and CD4+ count showed a significant association with all three criteria in univariate analysis. Additionally, tritan CCS was significantly associated with conjunctival blood-flow sludging. CCS deficits in patients with HIV disease are primarily associated with the number of cotton

Digital color imaging

CERN Document Server

Fernandez-Maloigne, Christine; Macaire, Ludovic

2013-01-01

This collective work identifies the latest developments in the field of the automatic processing and analysis of digital color images.For researchers and students, it represents a critical state of the art on the scientific issues raised by the various steps constituting the chain of color image processing.It covers a wide range of topics related to computational color imaging, including color filtering and segmentation, color texture characterization, color invariant for object recognition, color and motion analysis, as well as color image and video indexing and retrieval. <

Photon harvesting, coloring and polarizing in photovoltaic cell integrated color filters: efficient energy routing strategies for power-saving displays.

Science.gov (United States)

Wen, Long; Chen, Qin; Song, Shichao; Yu, Yan; Jin, Lin; Hu, Xin

2015-07-03

We describe the integral electro-optical strategies that combine the functionalities of photovoltaic (PV) electricity generation and color filtering as well as polarizing to realize more efficient energy routing in display technology. Unlike the conventional pigment-based filters and polarizers, which absorb substantial amounts of unwanted spectral components and dissipate them in the form of heat, we propose converting the energy of those photons into electricity by constructing PV cell-integrated color filters based on a selectively transmitting aluminum (Al) rear electrode perforated with nanoholes (NHs). Combining with a dielectric-metal-dielectric (DMD) front electrode, the devices were optimized to enable efficient cavity-enhanced photon recycling in the PV functional layers. We perform a comprehensive theoretical and numerical analysis to explore the extraordinary optical transmission (EOT) through the Al NHs and identify basic design rules for achieving structural coloring or polarizing in our PV color filters. We show that the addition of thin photoactive polymer layers on the symmetrically configured Al NH electrode narrows the bandwidth of the EOT-assisted high-pass light filtering due to the strongly damped anti-symmetric coupling of the surface modes excited on the front and rear surface of the Al NHs, which facilitates the whole visible coloring with relatively high purity for the devices. By engineering the cut-off characteristics of the plasmonic waveguide mode supported by the circular or ellipsoidal Al NHs, beyond the photon recycling capacity, PV color filters and PV polarizing color filters that allow polarization-insensitive and strong polarization-anisotropic color filtering were demonstrated. The findings presented here may shed some light on expanding the utilization of PV electricity generation across new-generation energy-saving electrical display devices.

Nonlinear dynamics in micromechanical and nanomechanical resonators and oscillators

Science.gov (United States)

Dunn, Tyler

In recent years, the study of nonlinear dynamics in microelectromechanical and nanoelectromechanical systems (MEMS and NEMS) has attracted considerable attention, motivated by both fundamental and practical interests. One example is the phenomenon of stochastic resonance. Previous measurements have established the presence of this counterintuitive effect in NEMS, showing that certain amounts of white noise can effectively amplify weak switching signals in nanomechanical memory elements and switches. However, other types of noise, particularly noises with 1/falpha spectra, also bear relevance in these and many other systems. At a more fundamental level, the role which noise color plays in stochastic resonance remains an open question in the field. To these ends, this work presents systematic measurements of stochastic resonance in a nanomechanical resonator using 1/f alpha and Ornstein-Uhlenbeck noise types. All of the studied noise spectra induce stochastic resonance, proving that colored noise can also be beneficial; however, stronger noise correlations suppress the effect, decreasing the maximum signal-to-noise ratio and increasing the optimal noise intensity. Evidence suggests that 1/falpha noise spectra with increasing noise color lead to increasingly asymmetric switching, reducing the achievable amplification. Another manifestly nonlinear effect anticipated in these systems is modal coupling. Measurements presented here demonstrate interactions between various mode types on a wide scale, providing the first reported observations of coupling in bulk longitudinal modes of MEMS. As a result of anharmonic elastic effects, each mode shifts in frequency by an amount proportional to the squared displacement (or energy) of a coupled mode. Since all resonator modes couple in this manner, these effects enable nonlinear measurement of energy and mechanical nonlinear signal processing across a wide range of frequencies. Finally, while these experiments address nonlinear

Nonlinear interaction of infrared waves on a VO2 surface at a semiconductor-metal phase transition

Science.gov (United States)

Berger, N. K.; Zhukov, E. A.; Novokhatskii, V. V.

1984-04-01

Nonlinear interactions (including wavefront reversal) of light from CW or pulsed 10.6-micron CO2 lasers at the semiconductor-metal phase transition in a VO2 film are investigated experimentally. The results are presented in graphs and characterized in detail. The intensity reflection coefficients of the three-wave interactions are found to be 0.5 percent for a CW reference wave of intensity 900 mW/sq cm and 42 percent for a pulsed reference wave of threshold density 600-800 microjoule/sq cm.

Finding the positive in all of the negative: Facilitation for color-related emotion words in a negative priming paradigm.

Science.gov (United States)

Sutton, Tina M; Altarriba, Jeanette

2016-10-01

A study conducted by Sutton and Altarriba (2008) suggested that color-related emotion words (e.g., sad, envy) produce standard Stroop interference effects. Associations between emotion words and colors are culture specific, and may be the result of common phrases in a language (e.g., "feeling blue" in English), or a result of the manner in which color is used to signify information or meaning in a language (e.g., red often represents threat). In the present paper, the same stimuli were investigated in a negative priming paradigm in which participants were asked to name the ink color of a presented word. In this task, response times are typically slower in ignored repetition trials (i.e., the probe target is related to the prime distractor) than control trials. The results of Experiment 1 indicated that color words and color-related neutral words yielded negative priming; however, color-related emotion words yielded significant facilitation. In Experiment 2, the three word types were intermixed within the same block and the same results were obtained. The current study provides converging evidence that salient distractors cannot be ignored. Copyright © 2016 Elsevier B.V. All rights reserved.

Using Single Colors and Color Pairs to Communicate Basic Tastes II: Foreground–Background Color Combinations

Science.gov (United States)

Marmolejo-Ramos, Fernando; Velasco, Carlos; Spence, Charles

2016-01-01

People associate basic tastes (e.g., sweet, sour, bitter, and salty) with specific colors (e.g., pink or red, green or yellow, black or purple, and white or blue). In the present study, we investigated whether a color bordered by another color (either the same or different) would give rise to stronger taste associations relative to a single patch of color. We replicate previous findings, highlighting the existence of a robust crossmodal correspondence between individual colors and basic tastes. On occasion, color pairs were found to communicate taste expectations more consistently than were single color patches. Furthermore, and in contrast to a recent study in which the color pairs were shown side-by-side, participants took no longer to match the color pairs with tastes than the single colors (they had taken twice as long to respond to the color pairs in the previous study). Possible reasons for these results are discussed, and potential applications for the results, and for the testing methodology developed, are outlined. PMID:27708752

How Redundant Are Redundant Color Adjectives? An Efficiency-Based Analysis of Color Overspecification

OpenAIRE

Rubio-Fern?ndez, Paula

2016-01-01

Color adjectives tend to be used redundantly in referential communication. I propose that redundant color adjectives are often intended to exploit a color contrast in the visual context and hence facilitate object identification, despite not being necessary to establish unique reference. Two language-production experiments investigated two types of factors that may affect the use of redundant color adjectives: factors related to the efficiency of color in the visual context and factors relate...

The nonlinear carrier transport in a bipolar semiconductor sample

International Nuclear Information System (INIS)

Konin, A

2008-01-01

A theory of formation of the voltage across a bipolar semiconductor sample due to the current flow accounting for the energy band bending near the semiconductor surfaces is presented. The non-equilibrium space charge layers near the sample surfaces and the boundary conditions in the real metal-semiconductor junction have been taken into account. It is shown that the voltage-current relation of a thin sample at weak injection differs essentially from the classical Ohm's law and becomes nonlinear for certain semiconductor surface parameters. Complex voltage-current relations and the photo-induced electromotive force measurements allow determining the surface recombination rate in the real metal-semiconductor junction and the semiconductor surface potential

Colorant modelling for on-line paper coloring: Evaluations of models and an extension to Kubelka-Munk model

Science.gov (United States)

Shakespeare, Tarja Tuulikki

Traditionally, single constant Kubelka-Munk type colorant formulation algorithms have been used for color control in the paper industry. Tuning data is derived from colored handsheets representing dyeing of a particular color grade, applicable to a substrate of similar properties. Due to furnish variation and changes in the chemical environment, such tuning data is of limited accuracy in practice. Kubelka-Munk approaches have numerous other limitations, in part due to their physically unrealistic assumptions. In particular, they neglect fluorescence phenomena, the interdependence of absorption and scattering, and nonlinearities due to colorant interactions. This thesis addresses those problems. A set of colored handsheets was made, employing several anionic direct dyes and fluorescent colorants, individually and in various combinations. Both a spectrophotometer and a spectrofluorimeter were used for measuring color properties. An extended Langmuir adsorption isotherm was used in modelling the dye-on- fiber in each dyeing. Kubelka-Munk absorption and scattering coefficients were then modelled based on dye- on-fiber, and a number of the limitations of the Kubelka- Munk approach were clearly demonstrated. An extended phenomenological model was derived, incorporating fluorescence and interdependence of absorption and scattering. This model predicts illuminator-independent radiance transfer factors based on dye-on-fiber, from which total radiance factor responses under arbitrary illumination can be computed. It requires spectrofluorometric measurements to characterize the coloring process. A new reflectance factor model, based on the same adsorption isotherm approach, was derived for non- fluorescent colorants. A corresponding total radiance factor model, which is illuminator-dependent, was derived for fluorescent colorants. These models have provision for phenomena such as broadening of absorption and scattering bands, which are encountered in practice. Being based on

Event-related potentials reveal linguistic suppression effect but not enhancement effect on categorical perception of color.

Science.gov (United States)

Lu, Aitao; Yang, Ling; Yu, Yanping; Zhang, Meichao; Shao, Yulan; Zhang, Honghong

2014-08-01

The present study used the event-related potential technique to investigate the nature of linguistic effect on color perception. Four types of stimuli based on hue differences between a target color and a preceding color were used: zero hue step within-category color (0-WC); one hue step within-category color (1-WC); one hue step between-category color (1-BC); and two hue step between-category color (2-BC). The ERP results showed no significant effect of stimulus type in the 100-200 ms time window. However, in the 200-350 ms time window, ERP responses to 1-WC target color overlapped with that to 0-WC target color for right visual field (RVF) but not left visual field (LVF) presentation. For the 1-BC condition, ERP amplitudes were comparable in the two visual fields, both being significantly different from the 0-WC condition. The 2-BC condition showed the same pattern as the 1-BC condition. These results suggest that the categorical perception of color in RVF is due to linguistic suppression on within-category color discrimination but not between-category color enhancement, and that the effect is independent of early perceptual processes. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Recent progress in color image intensifier

International Nuclear Information System (INIS)

Nittoh, K.

2010-01-01

A multi-color scintillator based high-sensitive, wide dynamic range and long-life X-ray image intensifier (Ultimage TM ) has been developed. Europium activated Y 2 O 2 S scintillator, emitting red, green and blue wavelength photons of different intensities, is utilized as the output fluorescent screen of the intensifier. By combining this image intensifier with a suitably tuned high sensitive color CCD camera, the sensitivity of the red color component achieved six times higher than that of the conventional image intensifier. Simultaneous emission of a moderate green color and a weak blue color covers different sensitivity regions. This widens the dynamic range by nearly two orders of magnitude. With this image intensifier, it is possible to image complex objects containing various different X-ray transmissions from paper, water or plastic to heavy metals at a time. This color scintillator based image intensifier is widely used in X-ray inspections of various fields. (author)

Chemical evolution of the solar neighborhood. II. The age-metallicity relation and the history of star formation in the galactic disk

International Nuclear Information System (INIS)

Twarog, B.A.

1980-01-01

The age-metallicty relation for the disk in the neighborhood of the Sun is derived from four-color and Hβ photometry of a large sample of southern F dwarfs, analyzed in combination with theoretical isochrones. It is found that the mean metallicity of the disk increased by about a factor of 5 between 12 and 5 billion years ago and has increased only slightly since then; this conclusion is independent of the helium abundance assumed for the models

Near-infrared metallicities, radial velocities, and spectral types for 447 nearby M dwarfs

Energy Technology Data Exchange (ETDEWEB)

Newton, Elisabeth R.; Charbonneau, David; Irwin, Jonathan; Berta-Thompson, Zachory K. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rojas-Ayala, Barbara [Centro de Astrofsica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Covey, Kevin [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States); Lloyd, James P., E-mail: enewton@cfa.harvard.edu [Department of Astronomy, Cornell University, 226 Space Sciences Building, Ithaca, NY 14853 (United States)

2014-01-01

We present metallicities, radial velocities, and near-infrared (NIR) spectral types for 447 M dwarfs determined from moderate resolution (R ≈ 2000) NIR spectra obtained with the NASA Infrared Telescope Facility (IRTF)/SpeX. These M dwarfs are primarily targets of the MEarth Survey, a transiting planet survey searching for super Earths around mid-to-late M dwarfs within 33 pc. We present NIR spectral types for each star and new spectral templates for the IRTF in the Y, J, H, and K-bands, created using M dwarfs with near-solar metallicities. We developed two spectroscopic distance calibrations that use NIR spectral type or an index based on the curvature of the K-band continuum. Our distance calibration has a scatter of 14%. We searched 27 NIR spectral lines and 10 spectral indices for metallicity sensitive features, taking into account correlated noise in our estimates of the errors on these parameters. We calibrated our relation using 36 M dwarfs in common proper pairs with an F-, G-, or K-type star of known metallicity. We validated the physical association of these pairs using proper motions, radial velocities, and spectroscopic distance estimates. Our resulting metallicity calibration uses the sodium doublet at 2.2 μm as the sole indicator for metallicity. It has an accuracy of 0.12 dex inferred from the scatter between the metallicities of the primaries and the estimated metallicities of the secondaries. Our relation is valid for NIR spectral types from M1V to M5V and for –1.0 dex < [Fe/H] < +0.35 dex. We present a new color-color metallicity relation using J – H and J – K colors that directly relates two observables: the distance from the M dwarf main sequence and equivalent width of the sodium line at 2.2 μm. We used radial velocities of M dwarf binaries, observations at different epochs, and comparison between our measurements and precisely measured radial velocities to demonstrate a 4 km s{sup –1} accuracy.

An event-related potential study on memory search for color

OpenAIRE

Miyatani, Makoto; Nakao, Takasi; Ohkawa, Kaori; Sanderson, Nicholas S. R.; Takumi, Ken

2002-01-01

The present study focused on memory search processes in nonverbal working memory. Event-related potentials (ERPs) were recorded while subjects engaged in two memory search tasks. Effects of memory set size on event-related potentials were compared between when memory sets consisted of one or four alphabets and when one to three unvocable color patches composed memory sets. In a letter search task, increase of memory set size caused the enlargement of negativities of ERPs between 250 and 450 m...

The confusing array of tooth-colored crowns.

Science.gov (United States)

Christensen, Gordon J

2003-09-01

The venerable PFM crown or fixed prosthesis still dominates the tooth-colored restoration market. However, use of PFMs is declining slightly, as the many new all-ceramic and resin-based composite crowns and fixed-prosthesis products flood the market. Several situations may indicate the use of materials other than PFM. They include patients requiring a high level of esthetic acceptability, patients with proven or perceived allergies to the metals used in dentistry and bruxing or clenching patients with metal allergies or desire to eliminate metal from their mouths. PFM restorations have been proven during 40 years of successful use. They provide acceptable esthetics for most situations, minimal fracture during service, proven ability to serve in multiple-unit situations and excellent fit, and the profession has detailed knowledge of these restorations' advantages, disadvantages and physical characteristics. PFM restorations have only a few well-known negative characteristics. Be cautious as you elect to move from the reliability and positive history of PFM to relatively unknown types of restorations.

The retention and disruption of color information in human short-term visual memory.

Science.gov (United States)

Nemes, Vanda A; Parry, Neil R A; Whitaker, David; McKeefry, Declan J

2012-01-27

Previous studies have demonstrated that the retention of information in short-term visual perceptual memory can be disrupted by the presentation of masking stimuli during interstimulus intervals (ISIs) in delayed discrimination tasks (S. Magnussen & W. W. Greenlee, 1999). We have exploited this effect in order to determine to what extent short-term perceptual memory is selective for stimulus color. We employed a delayed hue discrimination paradigm to measure the fidelity with which color information was retained in short-term memory. The task required 5 color normal observers to discriminate between spatially non-overlapping colored reference and test stimuli that were temporally separated by an ISI of 5 s. The points of subjective equality (PSEs) on the resultant psychometric matching functions provided an index of performance. Measurements were made in the presence and absence of mask stimuli presented during the ISI, which varied in hue around the equiluminant plane in DKL color space. For all reference stimuli, we found a consistent mask-induced, hue-dependent shift in PSE compared to the "no mask" conditions. These shifts were found to be tuned in color space, only occurring for a range of mask hues that fell within bandwidths of 29-37 deg. Outside this range, masking stimuli had little or no effect on measured PSEs. The results demonstrate that memory masking for color exhibits selectivity similar to that which has already been demonstrated for other visual attributes. The relatively narrow tuning of these interference effects suggests that short-term perceptual memory for color is based on higher order, non-linear color coding. © ARVO

Numerical Analysis on Color Preference and Visual Comfort from Eye Tracking Technique

Directory of Open Access Journals (Sweden)

Ming-Chung Ho

2015-01-01

Full Text Available Color preferences in engineering are very important, and there exists relationship between color preference and visual comfort. In this study, there are thirty university students who participated in the experiment, supplemented by pre- and posttest questionnaires, which lasted about an hour. The main purpose of this study is to explore the visual effects of different color assignment with subjective color preferences via eye tracking technology. Eye-movement data through a nonlinear analysis detect slight differences in color preferences and visual comfort, suggesting effective physiological indicators as extensive future research discussed. Results found that the average pupil size of eye-movement indicators can effectively reflect the differences of color preferences and visual comfort. This study more confirmed that the subjective feeling will make people have misjudgment.

Effect of Asymmetric Potential and Gaussian Colored Noise on Stochastic Resonance

International Nuclear Information System (INIS)

Han Yinxia; Li Jinghui; Chen Shigang

2005-01-01

The phenomenon of stochastic resonance (SR) in a bistable nonlinear system is studied when the system is driven by the asymmetric potential and additive Gaussian colored noise. Using the unified colored noise approximation method, the additive Gaussian colored noise can be simplified to additive Gaussian white noise. The signal-to-noise ratio (SNR) is calculated according to the generalized two-state theory (shown in [H.S. Wio and S. Bouzat, Brazilian J. Phys. 29 (1999) 136]). We find that the SNR increases with the proximity of a to zero. In addition, the correlation time τ between the additive Gaussian colored noise is also an ingredient to improve SR. The shorter the correlation time τ between the Gaussian additive colored noise is, the higher of the peak value of SNR.

Effects of multi-metal toxicity on the performance of sewage treatment system during the festival of colors (Holi) in India.

Science.gov (United States)

Tyagi, Vinay Kumar; Bhatia, Akanksha; Gaur, Rubia Zahid; Khan, Abid Ali; Ali, Muntajir; Khursheed, Anwar; Kazmi, Absar Ahmad

2012-12-01

The present study investigated the effects of heavy metals (Ni, Zn, Cd, Cu, and Pb) toxicity on the performance of 18 MLD activated sludge process-based sewage treatment plant (STP) during celebration of Holi (festival of colors in India). The composite sampling (n = 32) was carried out during the entire study period. The findings show a significant decrease in chemical oxygen demand removal efficiency (20%) of activated sludge system, after receiving the heavy metals laden wastewater. A significant reduction of 40% and 60% were observed in MLVSS/MLSS ratio and specific oxygen uptake rate, which eventually led to a substantial decrease in biomass growth yield (from 0.54 to 0.17). The toxic effect of metals ions was also observed on protozoan population. Out of the 12 mixed liquor species recorded, only two ciliates species of Vorticella and Epistylis exhibited the greater tolerance against heavy metals toxicity. Furthermore, activated sludge shows the highest metal adsorption affinity for Cu, followed by Zn, Pb, Ni, and Cd (Cu > Zn > Pb > Ni > Cd). Finally, this study proves the robustness of activated sludge system against the sudden increase in heavy metal toxicity since it recovered the earlier good quality performance within 5 days.

Encyclopedia of color science and technology

CERN Document Server

2016-01-01

The Encyclopedia of Color Science and Technology provides an authoritative single source for understanding and applying the concepts of color to all fields of science and technology, including artistic and historical aspects of color. Many topics are discussed in this timely reference, including an introduction to the science of color, and entries on the physics, chemistry and perception of color. Color is described as it relates to optical phenomena of color and continues on through colorants and materials used to modulate color and also to human vision of color. The measurement of color is provided as is colorimetry, color spaces, color difference metrics, color appearance models, color order systems and cognitive color. Other topics discussed include industrial color, color imaging, capturing color, displaying color and printing color. Descriptions of color encodings, color management, processing color and applications relating to color synthesis for computer graphics are included in this work. The Encyclo...

Active Color Control in a Metasurface by Polarization Rotation

Directory of Open Access Journals (Sweden)

Minkyung Kim

2018-06-01

Full Text Available Generating colors by employing metallic nanostructures has attracted intensive scientific attention recently, because one can easily realize higher spatial resolution and highly robust colors compared to conventional pigment. However, since the scattering spectra and thereby the resultant colors are determined by the nanostructure geometries, only one fixed color can be produced by one design and a whole new sample is required to generate a different color. In this paper, we demonstrate active metasurface, which shows a range of colors dependent on incident polarization by selectively exciting three different plasmonic nanorods. The metasurface, which does not include any tunable materials or external stimuli, will be beneficial in real-life applications especially in the display applications.

Sensitive color dosimeters using photochromic diarylethenes

International Nuclear Information System (INIS)

Irie, Setsuko; Irie, Masahiro

2008-01-01

Various types of color dosimeters are conveniently used for estimating absorbed dose in the radiation sterilization of biomedical materials. Diarylethenes with heterocyclic aryl groups are extensively studied for the applications to the optoelectronic devices, such as optical memory media and photowitching devices because of their thermally irreversible and fatigue-resistant properties. The colors of diarylethenes never fade in the dark conditions. The thermally stable dithienylethene derivatives are applied to sensitive color dosimeters. Upon γ-irradiation, polystyrene films containing diarylethene derivatives, such as 1,2-bis(2-methyl-5-phenyl-3-thienyl) perfluorocyclopentene 1 or 1,2-bis(2,5-dimethyl-3-thienyl) perfluorocyclopentene 2, and fluorescent metal complexes turned blue or red. Even if the absorbed dose was as small as 10 Gy, a clear color change was observed. (author)

Exchange Rate – Relative Price Nonlinear Cointegration Relationship in Malaysia

OpenAIRE

Venus Khim-Sen Liew; Chee-Keong Choong; Evan Lau; Kian-Ping Lim

2005-01-01

The finding of exchange rate–relative price nonlinear cointegration relationship in Malaysia, among others, suggests that nonlinear Purchasing Power Parity (PPP) equilibrium may be regarded as reference point in judging the short run misalignment of the Ringgit currency and thereby deducing effective policy actions. Moreover, economists who wish to extend the simple PPP exchange rate model into the more complicated monetary exchange models may do so comfortably, at least in the text of Mala...

Color-quality control using color-difference formulas: progress and problems

Science.gov (United States)

Melgosa, M.; Gómez-Robledo, L.; García, P. A.; Morillas, S.; Fernández-Maloigne, C.; Richard, N.; Huang, M.; Li, C.; Cui, G.

2017-08-01

We report on some recent advances in industrial color-difference evaluation focused in three main fields: Development of reliable experimental visual datasets; proposal of new color spaces and color-difference formulas; tools to evaluate the merits of color-difference formulas. The use of fuzzy techniques to assign consistency degrees to color pairs in combined visual datasets is described. The CIE/ISO joint proposal of the CIEDE2000 color-difference formula as a standard will facilitate the communication among companies and users. The CIE recommendation of the STRESS index to assess observers' variability and relative merits of different color-difference formulas is reported. Power functions are an efficient method to improve the performance of modern color-difference formulas. We need of advanced color-difference formulas accounting for new materials with different kind of textures and gonioapparent effects.

Stability of nonlinear waves and patterns and related topics

Science.gov (United States)

Ghazaryan, Anna; Lafortune, Stephane; Manukian, Vahagn

2018-04-01

Periodic and localized travelling waves such as wave trains, pulses, fronts and patterns of more complex structure often occur in natural and experimentally built systems. In mathematics, these objects are realized as solutions of nonlinear partial differential equations. The existence, dynamic properties and bifurcations of those solutions are of interest. In particular, their stability is important for applications, as the waves that are observable are usually stable. When the waves are unstable, further investigation is warranted of the way the instability is exhibited, i.e. the nature of the instability, and also coherent structures that appear as a result of an instability of travelling waves. A variety of analytical, numerical and hybrid techniques are used to study travelling waves and their properties. This article is part of the theme issue `Stability of nonlinear waves and patterns and related topics'.

Diagnostics of transparent polymer coatings of metal items

Science.gov (United States)

Varepo, L. G.; Ermakova, I. N.; Nagornova, I. V.; Kondratov, A. P.

2017-08-01

The methods of visual and instrumental express diagnostics of safety critical defects and non-uniform thickness of transparent mono- and multilayer polyolefin surface coating of metal items are analyzed in the paper. The instrumental diagnostics method relates to colorimetric measuring based on effects, which appear in the polarized light for extrusion polymer coatings. A color coordinates dependence (in the color system CIE La*b*) on both HDPE / PVC coating thickness fluctuation values (from average ones) and coating interlayer or adhesion layer delaminating is shown. A variation of color characteristics in the polarized light at a liquid penetration into delaminated polymer layers is found. Measuring parameters and critical uncertainties are defined.

Using Single Colors and Color Pairs to Communicate Basic Tastes

Directory of Open Access Journals (Sweden)

Andy T. Woods

2016-07-01

Full Text Available Recently, it has been demonstrated that people associate each of the basic tastes (e.g., sweet, sour, bitter, and salty with specific colors (e.g., red, green, black, and white. In the present study, we investigated whether pairs of colors (both associated with a particular taste or taste word would give rise to stronger associations relative to pairs of colors that were associated with different tastes. We replicate the findings of previous studies highlighting the existence of a robust crossmodal correspondence between individual colors and basic tastes. However, while there was evidence that pairs of colors could indeed communicate taste information more consistently than single colors, our participants took more than twice as long to match the color pairs with tastes than the single colors. Possible reasons for these results are discussed.

Using Single Colors and Color Pairs to Communicate Basic Tastes.

Science.gov (United States)

Woods, Andy T; Spence, Charles

2016-01-01

Recently, it has been demonstrated that people associate each of the basic tastes (e.g., sweet, sour, bitter, and salty) with specific colors (e.g., red, green, black, and white). In the present study, we investigated whether pairs of colors (both associated with a particular taste or taste word) would give rise to stronger associations relative to pairs of colors that were associated with different tastes. We replicate the findings of previous studies highlighting the existence of a robust crossmodal correspondence between individual colors and basic tastes. However, while there was evidence that pairs of colors could indeed communicate taste information more consistently than single colors, our participants took more than twice as long to match the color pairs with tastes than the single colors. Possible reasons for these results are discussed.

Relative controllability of nonlinear systems with delays in state and ...

African Journals Online (AJOL)

In this work, sufficient conditions are developed for the relative controllability of perturbed nonlinear systems with time varying multiple delays in control with the perturbation function having implicit derivative with delays depending on both state and control variable, using Darbo's fixed points theorem. Journal of the Nigerian ...

Individual visual working memory capacities and related brain oscillatory activities are modulated by color preferences.

Science.gov (United States)

Kawasaki, Masahiro; Yamaguchi, Yoko

2012-01-01

Subjective preferences affect many processes, including motivation, along with individual differences. Although incentive motivations are proposed to increase our limited visual working memory (VWM) capacity, much less is known about the effects of subjective preferences on VWM-related brain systems, such as the prefrontal and parietal cortices. Here, we investigate the differences in VWM capacities and brain activities during presentation of preferred and non-preferred colors. To this end, we used time-frequency (TF) analyses of electroencephalograph (EEG) data recorded during a delayed-response task. Behavioral results showed that the individual VWM capacities of preferred colors were significantly higher than those of non-preferred colors. The EEG results showed that the frontal theta and beta amplitudes for maintenance of preferred colors were higher than those of non-preferred colors. Interestingly, the frontal beta amplitudes were consistent with recent EEG recordings of the effects of reward on VWM systems, in that they were strongly and individually correlated with increasing VWM capacities from non-preferred to preferred colors. These results suggest that subjective preferences affect VWM systems in a similar manner to reward-incentive motivations.

How redundant are redundant color adjectives? An efficiency-based analysis of color overspecification

Directory of Open Access Journals (Sweden)

Paula eRubio-Fernández

2016-02-01

Full Text Available Color adjectives tend to be used redundantly in referential communication. I propose that redundant color adjectives are often intended to exploit a color contrast in the visual context and hence facilitate object identification, despite not being necessary to establish unique reference. Two language-production experiments investigated two types of factors that may affect the use of redundant color adjectives: factors related to the efficiency of color in the visual context and factors related to the semantic category of the noun. The results of Experiment 1 confirmed that people produce redundant color adjectives when color may facilitate object recognition; e.g., they do so more often in polychrome displays than in monochrome displays, and more often in English (pre-nominal position than in Spanish (post-nominal position. Redundant color adjectives are also used when color is a central property of the object category; e.g., people referred to the color of clothes more often than to the color of geometrical figures (Experiment 1, and they overspecified atypical colors more often than variable and stereotypical colors (Experiment 2. These results are relevant for pragmatic models of referential communication based on Gricean pragmatics and informativeness. An alternative analysis is proposed, which focuses on the efficiency and pertinence of color in a given referential situation.

The Carnegie Supernova Project: Intrinsic colors of type Ia supernovae

International Nuclear Information System (INIS)

Burns, Christopher R.; Persson, S. E.; Freedman, Wendy L.; Madore, Barry F.; Stritzinger, Maximilian; Contreras, Carlos; Phillips, M. M.; Hsiao, E. Y.; Boldt, Luis; Campillay, Abdo; Castellón, Sergio; Morrell, Nidia; Salgado, Francisco; Folatelli, Gaston; Suntzeff, Nicholas B.

2014-01-01

We present an updated analysis of the intrinsic colors of Type Ia supernova (SNe Ia) using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of 'normal' SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B – V light-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of R V , though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, R V , and the color excess, E(B – V), such that larger E(B – V) tends to favor lower R V . The intrinsic u-band colors show a relatively large scatter that cannot be explained by variations in R V or by the Goobar power-law for circumstellar dust, but rather is correlated with spectroscopic features of the supernova and is therefore likely due to metallicity effects.

Three-Dimensional Reconstruction of Nuclear Envelope Architecture Using Dual-Color Metal-Induced Energy Transfer Imaging.

Science.gov (United States)

Chizhik, Anna M; Ruhlandt, Daja; Pfaff, Janine; Karedla, Narain; Chizhik, Alexey I; Gregor, Ingo; Kehlenbach, Ralph H; Enderlein, Jörg

2017-12-26

The nuclear envelope, comprising the inner and the outer nuclear membrane, separates the nucleus from the cytoplasm and plays a key role in cellular functions. Nuclear pore complexes (NPCs), which are embedded in the nuclear envelope, control transport of macromolecules between the two compartments. Here, using dual-color metal-induced energy transfer (MIET), we determine the axial distance between Lap2β and Nup358 as markers for the inner nuclear membrane and the cytoplasmic side of the NPC, respectively. Using MIET imaging, we reconstruct the 3D profile of the nuclear envelope over the whole basal area, with an axial resolution of a few nanometers. This result demonstrates that optical microscopy can achieve nanometer axial resolution in biological samples and without recourse to complex interferometric approaches.

Relation between consumers' perceptions of color and texture of dairy desserts and instrumental measurements using a generalized procrustes analysis.

Science.gov (United States)

González-Tomás, L; Costell, E

2006-12-01

Consumers' perceptions of the color and texture of 8 commercial vanilla dairy desserts were studied and related to color and rheological measurements. First, the 8 desserts were evaluated by a group of consumers by means of the Free Choice Profile. For both color and texture, a 2-dimensional solution was chosen, with dimension 1 highly related to yellow color intensity in the case of color and to thickness in the case of texture. Second, mechanical spectra, flow behavior, and instrumental color were determined. All the samples showed a time-dependent and shear-thinning flow and a mechanical spectrum typical of a weak gel. Differences were found in the flow index, in the apparent viscosity at 10 s(-1), and in the values of the storage modulus, the loss modulus, the loss angle tangent, and the complex viscosity at 1 Hz, as well as in the color parameters. Finally, sensory and instrumental relationships were investigated by a generalized Procrustes analysis. For both color and texture, a 3-dimensional solution explained a high percentage of the total variance (>80%). In these particular samples, the instrumental color parameters provided more accurate information on consumers' color perceptions than was provided by the rheological parameters of consumers' perceptions of texture.

Hewlett-Packard's Approaches to Full Color Reflective Displays

Science.gov (United States)

Gibson, Gary

2012-02-01

Reflective displays are desirable in applications requiring low power or daylight readability. However, commercial reflective displays are currently either monochrome or capable of only dim color gamuts. Low cost, high-quality color technology would be rapidly adopted in existing reflective display markets and would enable new solutions in areas such as retail pricing and outdoor digital signage. Technical breakthroughs are required to enable bright color gamuts at reasonable cost. Pixel architectures that rely on pure reflection from a single layer of side-by-side primary-color sub-pixels use only a fraction of the display area to reflect incident light of a given color and are, therefore, unacceptably dark. Reflective devices employing stacked color primaries offer the possibility of a somewhat brighter color gamut but can be more complex to manufacture. In this talk, we describe HP's successes in addressing these fundamental challenges and creating both high performance stacked-primary reflective color displays as well as inexpensive single layer prototypes that provide good color. Our stacked displays utilize a combination of careful light management techniques, proprietary high-contrast electro-optic shutters, and highly transparent active-matrix TFT arrays based on transparent metal oxides. They also offer the possibility of relatively low cost manufacturing through roll-to-roll processing on plastic webs. To create even lower cost color displays with acceptable brightness, we have developed means for utilizing photoluminescence to make more efficient use of ambient light in a single layer device. Existing reflective displays create a desired color by reflecting a portion of the incident spectrum while absorbing undesired wavelengths. We have developed methods for converting the otherwise-wasted absorbed light to desired wavelengths via tailored photoluminescent composites. Here we describe a single active layer prototype display that utilizes these materials

Gender and engineering aptitude: Is the color of science, technology, engineering, and math materials related to children's performance?

Science.gov (United States)

Mulvey, Kelly Lynn; Miller, Bridget; Rizzardi, Victoria

2017-08-01

To investigate gender stereotypes, demonstrated engineering aptitude, and attitudes, children (N=105) solved an engineering problem using either pastel-colored or primary-colored materials. Participants also evaluated the acceptability of denial of access to engineering materials based on gender and counter-stereotypic preferences (i.e., a boy who prefers pastel-colored materials). Whereas material color was not related to differences in female participants' performance, younger boys assigned to pastel materials demonstrated lower engineering aptitude than did other participants. In addition, results documented age- and gender-related differences; younger participants, and sometimes boys, exhibited less flexibility regarding gender stereotypes than did older and female participants. The findings suggest that attempts to enhance STEM (science, technology, engineering, and math) engagement or performance through the color of STEM materials may have unintended consequences. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of weak nonlinearity on dispersion relations and frequency band-gaps of periodic structures

DEFF Research Database (Denmark)

Sorokin, Vladislav; Thomsen, Jon Juel

2015-01-01

of these for nonlinear problems is impossible or cumbersome, since Floquet theory is applicable for linear systems only. Thus the nonlinear effects for periodic structures are not yet fully uncovered, while at the same time applica-tions may demand effects of nonlinearity on structural response to be accounted for....... The present work deals with analytically predicting dynamic responses for nonlinear continuous elastic periodic structures. Specifically, the effects of weak nonlinearity on the dispersion re-lation and frequency band-gaps of a periodic Bernoulli-Euler beam performing bending os-cillations are analyzed......The analysis of the behaviour of linear periodic structures can be traced back over 300 years, to Sir Isaac Newton, and still attracts much attention. An essential feature of periodic struc-tures is the presence of frequency band-gaps, i.e. frequency ranges in which waves cannot propagate...

Nonlinear cosmological consistency relations and effective matter stresses

International Nuclear Information System (INIS)

Ballesteros, Guillermo; Hollenstein, Lukas; Jain, Rajeev Kumar; Kunz, Martin

2012-01-01

We propose a fully nonlinear framework to construct consistency relations for testing generic cosmological scenarios using the evolution of large scale structure. It is based on the covariant approach in combination with a frame that is purely given by the metric, the normal frame. As an example, we apply this framework to the ΛCDM model, by extending the usual first order conditions on the metric potentials to second order, where the two potentials start to differ from each other. We argue that working in the normal frame is not only a practical choice but also helps with the physical interpretation of nonlinear dynamics. In this frame, effective pressures and anisotropic stresses appear at second order in perturbation theory, even for ''pressureless'' dust. We quantify their effect and compare them, for illustration, to the pressure of a generic clustering dark energy fluid and the anisotropic stress in the DGP model. Besides, we also discuss the effect of a mismatch of the potentials on the determination of galaxy bias

Impact of Congenital Color Vision Defect on Color‑related Tasks ...

African Journals Online (AJOL)

Table 1]. In activities of daily .... Watching sports because of color of team jersey. 1628 (99.6). 2 (0.1). 2 (0.1). 1 (0.1). 2 (0.1). 1635 (100) .... difficulty with selecting colors of clothes, identifying colors in sports, workplace, hobbies, and road signals.

Sparse PDF maps for non-linear multi-resolution image operations

KAUST Repository

Hadwiger, Markus; Sicat, Ronell Barrera; Beyer, Johanna; Krü ger, Jens J.; Mö ller, Torsten

2012-01-01

feasible for gigapixel images, while enabling direct evaluation of a variety of non-linear operators from the same representation. We illustrate this versatility for antialiased color mapping, O(n) local Laplacian filters, smoothed local histogram filters

Similar star formation rate and metallicity variability time-scales drive the fundamental metallicity relation

Science.gov (United States)

Torrey, Paul; Vogelsberger, Mark; Hernquist, Lars; McKinnon, Ryan; Marinacci, Federico; Simcoe, Robert A.; Springel, Volker; Pillepich, Annalisa; Naiman, Jill; Pakmor, Rüdiger; Weinberger, Rainer; Nelson, Dylan; Genel, Shy

2018-06-01

The fundamental metallicity relation (FMR) is a postulated correlation between galaxy stellar mass, star formation rate (SFR), and gas-phase metallicity. At its core, this relation posits that offsets from the mass-metallicity relation (MZR) at a fixed stellar mass are correlated with galactic SFR. In this Letter, we use hydrodynamical simulations to quantify the time-scales over which populations of galaxies oscillate about the average SFR and metallicity values at fixed stellar mass. We find that Illustris and IllustrisTNG predict that galaxy offsets from the star formation main sequence and MZR oscillate over similar time-scales, are often anticorrelated in their evolution, evolve with the halo dynamical time, and produce a pronounced FMR. Our models indicate that galaxies oscillate about equilibrium SFR and metallicity values - set by the galaxy's stellar mass - and that SFR and metallicity offsets evolve in an anticorrelated fashion. This anticorrelated variability of the metallicity and SFR offsets drives the existence of the FMR in our models. In contrast to Illustris and IllustrisTNG, we speculate that the SFR and metallicity evolution tracks may become decoupled in galaxy formation models dominated by feedback-driven globally bursty SFR histories, which could weaken the FMR residual correlation strength. This opens the possibility of discriminating between bursty and non-bursty feedback models based on the strength and persistence of the FMR - especially at high redshift.

Effects of a multi-quark interaction on color superconducting phase transition in an extended NJL model

International Nuclear Information System (INIS)

Kashiwa, Kouji; Matsuzaki, Masayuki; Kouno, Hiroaki; Yahiro, Masanobu

2007-01-01

We study the interplay of the chiral and the color superconducting phase transition in an extended Nambu-Jona-Lasinio model with a multi-quark interaction that produces the nonlinear chiral-diquark coupling. We observe that this nonlinear coupling adds up coherently with the ω 2 interaction to either produce the chiral-color superconductivity coexistence phase or cancel each other depending on its sign. We discuss that a large coexistence region in the phase diagram is consistent with the quark-diquark picture for the nucleon whereas its smallness is the prerequisite for the applicability of the Ginzburg-Landau approach

Ultrafast nonlinear dynamics of thin gold films due to an intrinsic delayed nonlinearity

Science.gov (United States)

Bache, Morten; Lavrinenko, Andrei V.

2017-09-01

Using long-range surface plasmon polaritons light can propagate in metal nano-scale waveguides for ultracompact opto-electronic devices. Gold is an important material for plasmonic waveguides, but although its linear optical properties are fairly well understood, the nonlinear response is still under investigation. We consider the propagation of pulses in ultrathin gold strip waveguides, modeled by the nonlinear Schrödinger equation. The nonlinear response of gold is accounted for by the two-temperature model, revealing it as a delayed nonlinearity intrinsic in gold. The consequence is that the measured nonlinearities are strongly dependent on pulse duration. This issue has so far only been addressed phenomenologically, but we provide an accurate estimate of the quantitative connection as well as a phenomenological theory to understand the enhanced nonlinear response as the gold thickness is reduced. In comparison with previous works, the analytical model for the power-loss equation has been improved, and can be applied now to cases with a high laser peak power. We show new fits to experimental data from the literature and provide updated values for the real and imaginary parts of the nonlinear susceptibility of gold for various pulse durations and gold layer thicknesses. Our simulations show that the nonlinear loss is inhibiting efficient nonlinear interaction with low-power laser pulses. We therefore propose to design waveguides suitable for the mid-IR, where the ponderomotive instantaneous nonlinearity can dominate over the delayed hot-electron nonlinearity and provide a suitable plasmonics platform for efficient ultrafast nonlinear optics.

Drosophila melanogaster Models of Metal-Related Human Diseases and Metal Toxicity.

Science.gov (United States)

Calap-Quintana, Pablo; González-Fernández, Javier; Sebastiá-Ortega, Noelia; Llorens, José Vicente; Moltó, María Dolores

2017-07-06

Iron, copper and zinc are transition metals essential for life because they are required in a multitude of biological processes. Organisms have evolved to acquire metals from nutrition and to maintain adequate levels of each metal to avoid damaging effects associated with its deficiency, excess or misplacement. Interestingly, the main components of metal homeostatic pathways are conserved, with many orthologues of the human metal-related genes having been identified and characterized in Drosophila melanogaster . Drosophila has gained appreciation as a useful model for studying human diseases, including those caused by mutations in pathways controlling cellular metal homeostasis. Flies have many advantages in the laboratory, such as a short life cycle, easy handling and inexpensive maintenance. Furthermore, they can be raised in a large number. In addition, flies are greatly appreciated because they offer a considerable number of genetic tools to address some of the unresolved questions concerning disease pathology, which in turn could contribute to our understanding of the metal metabolism and homeostasis. This review recapitulates the metabolism of the principal transition metals, namely iron, zinc and copper, in Drosophila and the utility of this organism as an experimental model to explore the role of metal dyshomeostasis in different human diseases. Finally, a summary of the contribution of Drosophila as a model for testing metal toxicity is provided.

THE METALLICITIES OF LOW STELLAR MASS GALAXIES AND THE SCATTER IN THE MASS-METALLICITY RELATION

International Nuclear Information System (INIS)

Zahid, H. J.; Bresolin, F.; Kewley, L. J.; Coil, A. L.; Davé, R.

2012-01-01

In this investigation, we quantify the metallicities of low-mass galaxies by constructing the most comprehensive census to date. We use galaxies from the Sloan Digital Sky Survey (SDSS) and DEEP2 survey and estimate metallicities from their optical emission lines. We also use two smaller samples from the literature that have metallicities determined by the direct method using the temperature sensitive [O III]λ4363 line. We examine the scatter in the local mass-metallicity (MZ) relation determined from ∼20,000 star-forming galaxies in the SDSS and show that it is larger at lower stellar masses, consistent with the theoretical scatter in the MZ relation determined from hydrodynamical simulations. We determine a lower limit for the scatter in metallicities of galaxies down to stellar masses of ∼10 7 M ☉ which is only slightly smaller than the expected scatter inferred from the SDSS MZ relation and significantly larger than what has been previously established in the literature. The average metallicity of star-forming galaxies increases with stellar mass. By examining the scatter in the SDSS MZ relation, we show that this is mostly due to the lowest metallicity galaxies. The population of low-mass, metal-rich galaxies have properties that are consistent with previously identified galaxies that may be transitional objects between gas-rich dwarf irregulars and gas-poor dwarf spheroidals and ellipticals.

Industrial Color Physics

CERN Document Server

Klein, Georg A

2010-01-01

This unique book starts with a short historical overview of the development of the theories of color vision and applications of industrial color physics. The three dominant factors producing color - light source, color sample, and observer - are described in detail. The standardized color spaces are shown and related color values are applied to characteristic color qualities of absorption as well as of effect colorants. The fundamentals of spectrometric and colorimetric measuring techniques together with specific applications are described. Theoretical models for radiative transfer in transparent, translucent, and opaque layers are detailed; the two, three, and multi-flux approximations are presented for the first time in a coherent formalism. These methods constitute the fundamentals not only for the important classical methods, but also modern methods of recipe prediction applicable to all known colorants. The text is supplied with 52 tables, more than 200 partially colored illustrations, an appendix, and a...

Analysis of metal-matrix composite structures. I - Micromechanics constitutive theory. II - Laminate analyses

Science.gov (United States)

Arenburg, R. T.; Reddy, J. N.

1991-01-01

The micromechanical constitutive theory is used to examine the nonlinear behavior of continuous-fiber-reinforced metal-matrix composite structures. Effective lamina constitutive relations based on the Abouli micromechanics theory are presented. The inelastic matrix behavior is modeled by the unified viscoplasticity theory of Bodner and Partom. The laminate constitutive relations are incorporated into a first-order deformation plate theory. The resulting boundary value problem is solved by utilizing the finite element method. Attention is also given to computational aspects of the numerical solution, including the temporal integration of the inelastic strains and the spatial integration of bending moments. Numerical results the nonlinear response of metal matrix composites subjected to extensional and bending loads are presented.

Retinal vascular caliber, iris color, and age-related macular degeneration in the Irish Nun Eye Study.

Science.gov (United States)

McGowan, Amy; Silvestri, Giuliana; Moore, Evelyn; Silvestri, Vittorio; Patterson, Christopher C; Maxwell, Alexander P; McKay, Gareth J

2014-12-18

To evaluate the relationship between retinal vascular caliber (RVC), iris color, and age-related macular degeneration (AMD) in elderly Irish nuns. Data from 1233 participants in the cross-sectional observational Irish Nun Eye Study were assessed from digital photographs with a standardized protocol using computer-assisted software. Macular images were graded according to the modified Wisconsin Age-related Maculopathy Grading System. Regression models were used to assess associations, adjusting for age, mean arterial blood pressure, body mass index, refraction, and fellow RVC. In total, 1122 (91%) participants had gradable retinal images of sufficient quality for vessel assessment (mean age: 76.3 years [range, 56-100 years]). In an unadjusted analysis, we found some support for a previous finding that individuals with blue iris color had narrower retinal venules compared to those with brown iris color (P < 0.05), but this was no longer significant after adjustment. Age-related macular degeneration status was categorized as no AMD, any AMD, and late AMD only. Individuals with any AMD (early or late AMD) had significantly narrower arterioles and venules compared to those with no AMD in an unadjusted analysis, but this was no longer significant after adjustment. A nonsignificant reduced risk of any AMD or late AMD only was observed in association with brown compared to blue iris color, in both unadjusted and adjusted analyses. Retinal vascular caliber was not significantly associated with iris color or early/late AMD after adjustment for confounders. A lower but nonsignificant AMD risk was observed in those with brown compared to blue iris color. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

Distributions and natural levels of related metals in a trophic pathway

International Nuclear Information System (INIS)

Lemons, J.D.

1976-06-01

The first objective was to test the hypothesis that metal distributions and trends in organisms are, in part, a function of metal positions in the periodic table in unpolluted ecosystems. The data have shown that large soil crustal abundance differences of related elements (e.g. alkali metals) are proportionately approximated in higher organisms. Concentration factors for related nutritious and nonessential and toxic metals were determined along a trophic pathway. When the concentration factors were reported as the concentration of a particular metal by itself, all metal concentrations increased along the trophic pathway. The second objective of this study was to test the hypothesis that distributions and natural levels of chemically related nonessential and toxic metals can better be known when the metals are reported as a ratio, in ash, of the nonessential or toxic metal to its chemically related nutritious metal (e.g. strontium/calcium) as the metals are transferred through trophic pathways. The data have shown that when this method of reporting metal abundances in trophic levels is used, nonessential and toxic metals are discriminated against, relative to their chemically related nutritious metal, as the metals are transferred through the trophic pathway levels. The third objective was designed to test the hypothesis that surface deposition of toxic metals upon plants influences the trends of metal abundances through trophic pathways. This study indicates that metal pollution in the form of deposition upon plant surfaces bypasses the discrimination mechanisms in plants, and consequently elevates the total body burden in herbivores. It is likely that there is no herbivore defense for this type of metal exposure, because herbivores have probably come to rely, in part, upon the discriminatory mechanism of plants throughout the course of evolutionary history to keep toxic metal burdens low

Are there different requirements for trace elements in eumelanin- and pheomelanin-based color production? A case study of two passerine species.

Science.gov (United States)

Zduniak, Piotr; Surmacki, Adrian; Erciyas-Yavuz, Kiraz; Chudzińska, Maria; Barałkiewicz, Danuta

2014-09-01

Melanin is the most common pigment in animal integuments including bird plumage. It has been shown that several trace elements may play roles in the production and signaling function of melanin-colored plumage. We investigated coloration and content of various metal elements in the rectrices of two insectivorous passerines, Common Redstarts (Phoenicurus phoenicurus) and Blackcaps (Sylvia atricapilla), which have eumelanin- and pheomelanin-based coloration, respectively. We hypothesized that 1) the two species would differ in concentrations of metals important in melanin synthesis (Ca, Fe, Cu, Zn), 2) differences in metal concentration levels would be related to feather coloration. Our study confirmed the first prediction and provides the first evidence that selected elements may play a greater role in pheomelanin than in eumelanin synthesis. Concentrations of three elements considered as important in melanin synthesis (Ca, Fe, Zn) were 52% to 93% higher in rusty colored Common Redstart feathers compared to the dark gray Blackcap feathers. However, element concentrations were not correlated with feather coloration or sex in either species. Our study suggests that, of the two melanin forms, pheomelanin synthesis may bear higher costs associated with the acquisition of specific elements or limited elements may create trade-offs between ornamentation and other physiological functions. Our findings warrant further investigations designed to better understand the roles of macro- and microelements in the synthesis of both forms of melanin. Copyright © 2014 Elsevier Inc. All rights reserved.

Music Retrieval Based on the Relation between Color Association and Lyrics

Science.gov (United States)

Nakamur, Tetsuaki; Utsumi, Akira; Sakamoto, Maki

Various methods for music retrieval have been proposed. Recently, many researchers are tackling developing methods based on the relationship between music and feelings. In our previous psychological study, we found that there was a significant correlation between colors evoked from songs and colors evoked only from lyrics, and showed that the music retrieval system using lyrics could be developed. In this paper, we focus on the relationship among music, lyrics and colors, and propose a music retrieval method using colors as queries and analyzing lyrics. This method estimates colors evoked from songs by analyzing lyrics of the songs. On the first step of our method, words associated with colors are extracted from lyrics. We assumed two types of methods to extract words associated with colors. In the one of two methods, the words are extracted based on the result of a psychological experiment. In the other method, in addition to the words extracted based on the result of the psychological experiment, the words from corpora for the Latent Semantic Analysis are extracted. On the second step, colors evoked from the extracted words are compounded, and the compounded colors are regarded as those evoked from the song. On the last step, colors as queries are compared with colors estimated from lyrics, and the list of songs is presented based on similarities. We evaluated the two methods described above and found that the method based on the psychological experiment and corpora performed better than the method only based on the psychological experiment. As a result, we showed that the method using colors as queries and analyzing lyrics is effective for music retrieval.

Comparison between two race/skin color classifications in relation to health-related outcomes in Brazil

Directory of Open Access Journals (Sweden)

Szwarcwald Celia L

2011-08-01

Full Text Available Abstract Background This paper aims to compare the classification of race/skin color based on the discrete categories used by the Demographic Census of the Brazilian Institute of Geography and Statistics (IBGE and a skin color scale with values ranging from 1 (lighter skin to 10 (darker skin, examining whether choosing one alternative or the other can influence measures of self-evaluation of health status, health care service utilization and discrimination in the health services. Methods This is a cross-sectional study based on data from the World Health Survey carried out in Brazil in 2003 with a sample of 5000 individuals older than 18 years. Similarities between the two classifications were evaluated by means of correspondence analysis. The effect of the two classifications on health outcomes was tested through logistic regression models for each sex, using age, educational level and ownership of consumer goods as covariables. Results Both measures of race/skin color represent the same race/skin color construct. The results show a tendency among Brazilians to classify their skin color in shades closer to the center of the color gradient. Women tend to classify their race/skin color as a little lighter than men in the skin color scale, an effect not observed when IBGE categories are used. With regard to health and health care utilization, race/skin color was not relevant in explaining any of them, regardless of the race/skin color classification. Lack of money and social class were the most prevalent reasons for discrimination in healthcare reported in the survey, suggesting that in Brazil the discussion about discrimination in the health care must not be restricted to racial discrimination and should also consider class-based discrimination. The study shows that the differences of the two classifications of race/skin color are small. However, the interval scale measure appeared to increase the freedom of choice of the respondent.

Physics of structural colors

International Nuclear Information System (INIS)

Kinoshita, S; Yoshioka, S; Miyazaki, J

2008-01-01

In recent years, structural colors have attracted great attention in a wide variety of research fields. This is because they are originated from complex interaction between light and sophisticated nanostructures generated in the natural world. In addition, their inherent regular structures are one of the most conspicuous examples of non-equilibrium order formation. Structural colors are deeply connected with recent rapidly growing fields of photonics and have been extensively studied to clarify their peculiar optical phenomena. Their mechanisms are, in principle, of a purely physical origin, which differs considerably from the ordinary coloration mechanisms such as in pigments, dyes and metals, where the colors are produced by virtue of the energy consumption of light. It is generally recognized that structural colors are mainly based on several elementary optical processes including thin-layer interference, diffraction grating, light scattering, photonic crystals and so on. However, in nature, these processes are somehow mixed together to produce complex optical phenomena. In many cases, they are combined with the irregularity of the structure to produce the diffusive nature of the reflected light, while in some cases they are accompanied by large-scale structures to generate the macroscopic effect on the coloration. Further, it is well known that structural colors cooperate with pigmentary colors to enhance or to reduce the brilliancy and to produce special effects. Thus, structure-based optical phenomena in nature appear to be quite multi-functional, the variety of which is far beyond our understanding. In this article, we overview these phenomena appearing particularly in the diversity of the animal world, to shed light on this rapidly developing research field

Ultrafast nonlinear dynamics of thin gold films due to an intrinsic delayed nonlinearity

DEFF Research Database (Denmark)

Bache, Morten; Lavrinenko, Andrei

2017-01-01

Using long-range surface plasmon polaritons light can propagate in metal nano-scale waveguides for ultracompact opto-electronic devices. Gold is an important material for plasmonic waveguides, but although its linear optical properties are fairly well understood, the nonlinear response is still...

[Patient-related color preference and color design in the hospital].

Science.gov (United States)

Schuschke, G; Christiansen, H

1994-06-01

Colour-physiological studies involving volunteers and colour-psychological interviewing of patients with varied diagnoses revealed that, currently, no compelling scientific reasons can be given for coloration in the hospital. Interviewing 68 patients from a number of clinics on the coloration of sick-rooms yielded the following preferred colours, irrespective of the patients' classing into groups by various criteria: Light colours were consistently preferred for all objects such as ceiling, walls, floor, curtains, furniture, and bed linen. It should be emphasized that even white was a desirable colour for ceilings and bed linen. Beige was found to rank first for walls, floors, curtains, and furniture, whereas the colours of wood and grey shared the second rank for floors and furniture. Green and pink ranked second for bed linen. White and green ranked second for walls and curtains, respectively. In view of the heterogeneity, the findings may not be converted into an absolute just as the recommendations by other workers. Still, the patients' wish should be given priority over decreed recommendations by experts when basic considerations of illumination (reflectance!) are allowed for in the particular overall colour design project.

Iron encrustations on filamentous algae colonized by Gallionella-related bacteria in a metal-polluted freshwater stream

Science.gov (United States)

Mori, J. F.; Neu, T. R.; Lu, S.; Händel, M.; Totsche, K. U.; Küsel, K.

2015-09-01

Filamentous macroscopic algae were observed in slightly acidic to circumneutral (pH 5.9-6.5), metal-rich stream water that leaked out from a former uranium mining district (Ronneburg, Germany). These algae differed in color and morphology and were encrusted with Fe-deposits. To elucidate their potential interaction with Fe(II)-oxidizing bacteria (FeOB), we collected algal samples at three time points during summer 2013 and studied the algae-bacteria-mineral compositions via confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectra, and a 16S and 18S rRNA gene-based bacterial and algae community analysis. Surprisingly, sequencing analysis of 18S rRNA gene regions of green and brown algae revealed high homologies with the freshwater algae Tribonema (99.9-100 %). CLSM imaging indicated a loss of active chloroplasts in the algae cells, which may be responsible for the change in color in oxidation under the putative oxygen-saturated conditions that occur in association with photosynthetic algae. Quantitative PCR (polymerase chain reaction) revealed even higher Gallionella-related 16S rRNA gene copy numbers on the surface of green algae compared to the brown algae. The latter harbored a higher microbial diversity, including some putative predators of algae. A loss of chloroplasts in the brown algae could have led to lower photosynthetic activities and reduced EPS production, which is known to affect predator colonization. Collectively, our results suggest the coexistence of oxygen-generating algae Tribonema sp. and strictly microaerophilic neutrophilic FeOB in a heavy metal-rich environment.

Color-Tunable and High-Efficiency Dye-Encapsulated Metal-Organic Framework Composites Used for Smart White-Light-Emitting Diodes.

Science.gov (United States)

Chen, Wenwei; Zhuang, Yixi; Wang, Le; Lv, Ying; Liu, Jianbin; Zhou, Tian-Liang; Xie, Rong-Jun

2018-05-25

Luminescent metal-organic frameworks (MOFs) (typically dye-encapsulated MOFs) are considered as one kind of interesting downconversion materials for white-light-emitting diodes (LEDs), but their quantum efficiency (QE) is not sufficient and thus needs to be significantly enhanced for practical applications. In this study, we successfully synthesized a series of Rh@bio-MOF-1 (Rh = rhodamine) with an internal QE as high as ∼79% via a solvothermal reaction followed by cation exchanges. The high efficiency of the Rh@bio-MOF-1 composites was attributable to the high intrinsic luminescent efficiency of the selected Rh dyes, the confinement effect in the bio-MOF-1 host, and the uniform particle morphology. The emission maximum could be continuously tuned from 550 to 610 nm by controlling the species and concentration of encapsulated dye molecules, showing great color tunability of the dye-encapsulated MOFs. The emission lifetime of ∼7 ns was 1 or 2 magnitude orders shorter than that of Ce 3+ - or Eu 2+ -doped inorganic phosphors, allowing for visible light communication (VLC). White LEDs, fabricated by using the synthesized Rh@bio-MOF-1 composite and inorganic phosphors of green (Ba,Sr) 2 SiO 4 :Eu 2+ and red CaAlSiN 3 :Eu 2+ , exhibited a high color rendering index of 80-94, a luminous efficacy of 94-156 lm/W, and an excellent stability in color point against drive current. The Rh@bio-MOF-1 composites with tunable colors, short emission lifetime, and high QE are expected to be used for smart white LEDs with multifunctions of both lighting and VLC.

The interaction between surface color and color knowledge: Behavioral and electrophysiological evidence

OpenAIRE

Bramão, I.; Faísca, L.; Forkstam, C.; Inácio, F.; Araújo, S.; Petersson, K.; Reis, A.

2012-01-01

In this study, we used event-related potentials (ERPs) to evaluate the contribution of surface color and color knowledge information in object identification. We constructed two color-object verification tasks – a surface and a knowledge verification task – using high color diagnostic objects; both typical and atypical color versions of the same object were presented. Continuous electroencephalogram was recorded from 26 subjects. A cluster randomization procedure was used to explore the diffe...

Individual visual working memory capacities and related brain oscillatory activities are modulated by color preferences

Directory of Open Access Journals (Sweden)

Masahiro eKawasaki

2012-11-01

Full Text Available Subjective preferences affect many processes, including motivation, along with individual differences. Although incentive motivations are proposed to increase our limited visual working memory (VWM capacity, much less is known about the effects of subjective preferences on VWM-related brain systems, such as the prefrontal and parietal cortices. Here, we investigate the differences in VWM capacities and brain activities during presentation of preferred and non-preferred colors. To this end, we used time-frequency analyses of electroencephalograph (EEG data recorded during a delayed-response task. Behavioral results showed that the individual VWM capacities of preferred colors were significantly higher than those of non-preferred colors. The EEG results showed that the frontal theta and beta amplitudes for maintenance of preferred colors were higher than those of non-preferred colors. Interestingly, the frontal beta amplitudes were consistent with recent EEG recordings of the effects of reward on VWM systems, in that they were strongly and individually correlated with increasing VWM capacities from non-preferred to preferred colors. These results suggest that subjective preferences affect VWM systems in a similar manner to reward-incentive motivations.

Neutral- and Multi-Colored Semitransparent Perovskite Solar Cells.

Science.gov (United States)

Lee, Kyu-Tae; Guo, L Jay; Park, Hui Joon

2016-04-11

In this review, we summarize recent works on perovskite solar cells with neutral- and multi-colored semitransparency for building-integrated photovoltaics and tandem solar cells. The perovskite solar cells exploiting microstructured arrays of perovskite "islands" and transparent electrodes-the latter of which include thin metallic films, metal nanowires, carbon nanotubes, graphenes, and transparent conductive oxides for achieving optical transparency-are investigated. Moreover, the perovskite solar cells with distinctive color generation, which are enabled by engineering the band gap of the perovskite light-harvesting semiconductors with chemical management and integrating with photonic nanostructures, including microcavity, are discussed. We conclude by providing future research directions toward further performance improvements of the semitransparent perovskite solar cells.

Relation between linear and nonlinear N=3,4 supergravity theories

International Nuclear Information System (INIS)

Sevrin, A.; Thielemans, K.; Troost, W.

1993-01-01

The effective actions for d=2, N=3,4 chiral supergravities with a linear and a nonlinear gauge algebra are related to each other by a quantum reduction; the latter is obtained from the former by putting quantum currents equal to zero. This implies that the renormalization factors for the quantum actions are identical

Color categories: Evidence for the cultural relativity hypothesis

OpenAIRE

Roberson, Debi; Davidoff, Jules B.; Davies, Ian R. L.; Shapiro, Laura R.

2005-01-01

The question of whether language affects our categorization of perceptual continua is of particular interest for the domain of color where constraints on categorization have been proposed both within the visual system and in the visual environment. Recent research (Roberson, Davies, & Davidoff, 2000; Roberson et al., in press) found substantial evidence of cognitive color differences between different language communities, but concerns remained as to how representative might be a tiny, extrem...

Oil Spill Related Heavy Metal: A Review

International Nuclear Information System (INIS)

Ahmad Dasuki Mustafa; Hafizan Juahir; Kamaruzzaman Yunus; Mohammad Azizi Amran; Che Noraini Che Hasnam; Fazureen Azaman; Ismail Zainal Abidin; Syahril Hirman Azmee; Nur Hishaam Sulaiman

2015-01-01

Oil spill occurs every day worldwide and oil contamination is a significant contributor for the higher levels of heavy metals in the environment. This study is purposely to summarize the heavy metals which significant to major oil spill incidents around the world and effects of toxic metals to human health. The study performed a comprehensive review of relevant scientific journal articles and government documents concerning heavy metals contamination and oil spills. Overall, the heavy metals most frequently been detected in oil spill related study where Pb>Ni>V>Zn>Cd and caused many effects to human health especially cancer. In conclusion, the comparison of heavy metal level between the post - spill and baseline levels must be done, and implementation of continuous monitoring of heavy metal. In addition, the result based on the strategies must be transparent to public in order to maintaining human health. (author)

A color-communication scheme for digital imagery

Science.gov (United States)

Acosta, Alex

1987-01-01

Color pictures generated from digital images are frequently used by geologists, foresters, range managers, and others. These color products are preferred over black and white pictures because the human eye is more sensitive to color differences than to various shades of gray. Color discrimination is a function of perception, and therefore colors in these color composites are generally described subjectively, which can lead to ambiguous color communication. Numerous color-coordinate systems are available that quantitively relate digital triplets representing amounts of red, free, and blue to the parameters of hue, saturation, and intensity perceived by the eye. Most of these systems implement a complex transformation of the primary colors to a color space that is hard to visualize, thus making it difficult to relate digital triplets to perception parameters. This paper presents a color-communcation scheme that relates colors on a color triangle to corresponding values of "hue" (H), "saturation" (S), and chromaticity coordinates (x,y,z). The scheme simplifies the relation between red, green, and blue (RGB) digital triplets and the color generated by these triplets. Some examples of the use of the color-communication scheme in digital image processing are presented.

Development of a model to select plants with optimum metal phytoextraction potential.

Science.gov (United States)

Guala, Sebastián D; Vega, Flora A; Covelo, Emma F

2011-07-01

The aim of the present study is to propose a nonlinear model which provides an indicator for the maximum phytoextraction of metals to help in the decision-making process. Research into different species and strategies plays an important role in the application of phytoextraction techniques to the remediation of contaminated soil. Also, the convenience of species according to their biomass and pollutant accumulation capacities has gained important space in discussions regarding remediation strategies, whether to choose species with low accumulation capacities and high biomass or high accumulation capacities with low biomass. The effects of heavy metals in soil on plant growth are studied by means of a nonlinear interaction model which relates the dynamics of the uptake of heavy metals by plants to heavy metal deposed in soil. The model, presented theoretically, provides an indicator for the maximum phytoextraction of metals which depends on adjustable parameters of both the plant and the environmental conditions. Finally, in order to clarify its applicability, a series of experimental results found in the literature are presented to show how the model performs consistently with real data. The inhibition of plant growth due to heavy metal concentration can be predicted by a simple kinetic model. The model proposed in this study makes it possible to characterize the nonlinear behaviour of the soil-plant interaction with heavy metal pollution in order to establish maximum uptake values for heavy metals in the harvestable part of plants.

Color-tunable mixed photoluminescence emission from Alq3 organic layer in metal-Alq3-metal surface plasmon structure.

Science.gov (United States)

Chen, Nai-Chuan; Liao, Chung-Chi; Chen, Cheng-Chang; Fan, Wan-Ting; Wu, Jin-Han; Li, Jung-Yu; Chen, Shih-Pu; Huang, Bohr-Ran; Lee, Li-Ling

2014-01-01

This work reports the color-tunable mixed photoluminescence (PL) emission from an Alq3 organic layer in an Au-Alq3-Au plasmonic structure through the combination of organic fluorescence emission and another form of emission that is enabled by the surface plasmons in the plasmonic structure. The emission wavelength of the latter depends on the Alq3 thickness and can be tuned within the Alq3 fluorescent spectra. Therefore, a two-color broadband, color-tunable mixed PL structure was obtained. Obvious changes in the Commission Internationale d'Eclairage (CIE) coordinates and the corresponding emission colors of Au-Alq3-Au samples clearly varied with the Alq3 thickness (90, 130, and 156 nm).

FURTHER DEFINITION OF THE MASS-METALLICITY RELATION IN GLOBULAR CLUSTER SYSTEMS AROUND BRIGHTEST CLUSTER GALAXIES

International Nuclear Information System (INIS)

Cockcroft, Robert; Harris, William E.; Wehner, Elizabeth M. H.; Whitmore, Bradley C.; Rothberg, Barry

2009-01-01

We combine the globular cluster (GC) data for 15 brightest cluster galaxies and use this material to trace the mass-metallicity relations (MMRs) in their globular cluster systems (GCSs). This work extends previous studies which correlate the properties of the MMR with those of the host galaxy. Our combined data sets show a mean trend for the metal-poor subpopulation that corresponds to a scaling of heavy-element abundance with cluster mass Z ∼ M 0.30±0.05 . No trend is seen for the metal-rich subpopulation which has a scaling relation that is consistent with zero. We also find that the scaling exponent is independent of the GCS specific frequency and host galaxy luminosity, except perhaps for dwarf galaxies. We present new photometry in (g',i') obtained with Gemini/GMOS for the GC populations around the southern giant ellipticals NGC 5193 and IC 4329. Both galaxies have rich cluster populations which show up as normal, bimodal sequences in the color-magnitude diagram. We test the observed MMRs and argue that they are statistically real, and not an artifact caused by the method we used. We also argue against asymmetric contamination causing the observed MMR as our mean results are no different from other contamination-free studies. Finally, we compare our method to the standard bimodal fitting method (KMM or RMIX) and find our results are consistent. Interpretation of these results is consistent with recent models for GC formation in which the MMR is determined by GC self-enrichment during their brief formation period.

Colored operads

CERN Document Server

Yau, Donald

2016-01-01

The subject of this book is the theory of operads and colored operads, sometimes called symmetric multicategories. A (colored) operad is an abstract object which encodes operations with multiple inputs and one output and relations between such operations. The theory originated in the early 1970s in homotopy theory and quickly became very important in algebraic topology, algebra, algebraic geometry, and even theoretical physics (string theory). Topics covered include basic graph theory, basic category theory, colored operads, and algebras over colored operads. Free colored operads are discussed in complete detail and in full generality. The intended audience of this book includes students and researchers in mathematics and other sciences where operads and colored operads are used. The prerequisite for this book is minimal. Every major concept is thoroughly motivated. There are many graphical illustrations and about 150 exercises. This book can be used in a graduate course and for independent study.

Color models of hadrons

International Nuclear Information System (INIS)

Greenberg, O.W.; Nelson, C.A.

1977-01-01

The evidence for a three-valued 'color' degree of freedom in hadron physics is reviewed. The structure of color models is discussed. Consequences of color models for elementary particle physics are discussed, including saturation properties of hadronic states, π 0 →2γ and related decays, leptoproduction, and lepton pair annihilation. Signatures are given which distinguish theories with isolated colored particles from those in which color is permanently bound. (Auth.)

Square bananas, blue horses: The relative weight of shape and color in concept recognition and representation

Directory of Open Access Journals (Sweden)

Claudia eScorolli

2015-10-01

Full Text Available The present study investigates the role that shape and color play in the representation of animate (i.e. animals and inanimate manipulable entities (i.e. fruits, and how the importance of these features is modulated by different tasks. Across three experiments participants were shown either images of entities (e.g., a sheep or a pineapple or images of the same entities modified in color (e.g. a blue pineapple or in shape (e.g. an elongated pineapple. In Experiment 1 we asked participants to categorize the entities as fruit or animal. Results showed that with animals color does not matter, while shape modifications determined a deterioration of the performance - stronger for fruit than for animals. To better understand the findings, in Experiment 2 participants were asked to judge if entities were graspable (manipulation evaluation task. Participants were faster with manipulable entities (fruit than with animals; moreover alterations in shape affected the response latencies more for animals than for fruit. In Experiment 3 (motion evaluation task, we replicated the disadvantage for shape-altered animals, while with fruits shape and color modifications produced no effect. By contrasting shape- and color- alterations the present findings provide information on shape/color relative weight, suggesting that the action based property of shape is more crucial than color for fruit categorization, while with animals it is critical for both manipulation and motion tasks. This contextual dependency is further revealed by explicit judgments on similarity - between the altered entities and the prototypical ones - provided after the different tasks. These results extend current literature on affordances and biofunctionally embodied understanding, revealing the relative robustness of biofunctional activity compared to intellectual one.

Vacancies and a generalised melting curve of metals

International Nuclear Information System (INIS)

Gorecki, T.

1979-01-01

The vacancy mechanism of the melting process is used as a starting point for deriving an expression for the pressure dependence of the melting temperature of metals. The results obtained for the initial slope of the melting curve are compared with experimental data for 45 metals and in most cases the agreement is very good. The nonlinearity of the melting curve and the appearance of a maximum on the melting curve at a pressure approximately equal to the bulk modules is also predicted, with qualitative agreement with experimental data. A relation between bonding energy, atomic volume, and bulk modulus of metals is established. On the basis of this relation and the proposed vacancy mechanism, a generalised equation for the pressure dependence of the melting temperature of metals is derived. (author)

Training synesthetic letter-color associations by reading in color

NARCIS (Netherlands)

Colizoli, O.; Murre, J.M.J.; Rouw, R.

2014-01-01

Synesthesia is a rare condition in which a stimulus from one modality automatically and consistently triggers unusual sensations in the same and/or other modalities. A relatively common and well-studied type is grapheme-color synesthesia, defined as the consistent experience of color when viewing,

The Carnegie Supernova Project: Intrinsic colors of type Ia supernovae

Energy Technology Data Exchange (ETDEWEB)

Burns, Christopher R.; Persson, S. E.; Freedman, Wendy L.; Madore, Barry F. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Stritzinger, Maximilian; Contreras, Carlos [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Phillips, M. M.; Hsiao, E. Y.; Boldt, Luis; Campillay, Abdo; Castellón, Sergio; Morrell, Nidia; Salgado, Francisco [Carnegie Institution of Washington, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile); Folatelli, Gaston [Kavli Institute for the Physics and Mathematics of the Universe, Todai Institutes for Advanced Study, the University of Tokyo, 277-8583 Kashiwa (Japan); Suntzeff, Nicholas B. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, Department of Physics and Astronomy, College Station, TX 77843 (United States)

2014-07-01

We present an updated analysis of the intrinsic colors of Type Ia supernova (SNe Ia) using the latest data release of the Carnegie Supernova Project. We introduce a new light-curve parameter very similar to stretch that is better suited for fast-declining events, and find that these peculiar types can be seen as extensions to the population of 'normal' SNe Ia. With a larger number of objects, an updated fit to the Lira relation is presented along with evidence for a dependence on the late-time slope of the B – V light-curves with stretch and color. Using the full wavelength range from u to H band, we place constraints on the reddening law for the sample as a whole and also for individual events/hosts based solely on the observed colors. The photometric data continue to favor low values of R{sub V} , though with large variations from event to event, indicating an intrinsic distribution. We confirm the findings of other groups that there appears to be a correlation between the derived reddening law, R{sub V} , and the color excess, E(B – V), such that larger E(B – V) tends to favor lower R{sub V} . The intrinsic u-band colors show a relatively large scatter that cannot be explained by variations in R{sub V} or by the Goobar power-law for circumstellar dust, but rather is correlated with spectroscopic features of the supernova and is therefore likely due to metallicity effects.

Progress in nonlinear nano-optics

CERN Document Server

Lienau, Christoph; Grunwald, Rüdiger

2015-01-01

This book presents the state of the art in nonlinear nanostructures for ultrafast laser applications. Most recent results in two emerging fields are presented: (i) generation of laser-induced nanostructures in materials like metals, metal oxides and semiconductors, and (ii) ultrafast excitation and energy transfer in nanoscale physical, chemical and hybrid systems. Particular emphasis is laid on the up-to-date controversially discussed mechanisms of sub-wavelength ripple formation including models of self-organized material transport and multiphoton excitation channels, nonlinear optics of plasmonic structures (nanotips, nanowires, 3D-metamaterials), and energy localization and transport on ultrafast time scale and spatial nanoscale. High-resolution spectroscopy, simulation and characterization techniques are reported. New applications of ultrashort-pulsed lasers for materials processing and the use of nanostructured materials for characterizing laser fields and laser-matter-interactions are discussed.

Imaging tristimulus colorimeter for the evaluation of color in printed textiles

Science.gov (United States)

Hunt, Martin A.; Goddard, James S., Jr.; Hylton, Kathy W.; Karnowski, Thomas P.; Richards, Roger K.; Simpson, Marc L.; Tobin, Kenneth W., Jr.; Treece, Dale A.

1999-03-01

The high-speed production of textiles with complicated printed patterns presents a difficult problem for a colorimetric measurement system. Accurate assessment of product quality requires a repeatable measurement using a standard color space, such as CIELAB, and the use of a perceptually based color difference formula, e.g. (Delta) ECMC color difference formula. Image based color sensors used for on-line measurement are not colorimetric by nature and require a non-linear transformation of the component colors based on the spectral properties of the incident illumination, imaging sensor, and the actual textile color. This research and development effort describes a benchtop, proof-of-principle system that implements a projection onto convex sets (POCS) algorithm for mapping component color measurements to standard tristimulus values and incorporates structural and color based segmentation for improved precision and accuracy. The POCS algorithm consists of determining the closed convex sets that describe the constraints on the reconstruction of the true tristimulus values based on the measured imperfect values. We show that using a simulated D65 standard illuminant, commercial filters and a CCD camera, accurate (under perceptibility limits) per-region based (Delta) ECMC values can be measured on real textile samples.

ARTICLES: Nonlinear interaction of infrared waves on a VO2 surface at a semiconductor-metal phase transition

Science.gov (United States)

Berger, N. K.; Zhukov, E. A.; Novokhatskiĭ, V. V.

1984-04-01

The use of a semiconductor-metal phase transition for wavefront reversal of laser radiation was proposed. An investigation was made of nonlinear reflection of CO2 laser radiation at a phase transition in VO2. A three-wave interaction on a VO2 surface was achieved using low-power cw and pulsed CO2 lasers. In the first case, the intensity reflection coefficient was 0.5% for a reference wave intensity of 0.9 W/cm2 and in the second case, it was 42% for a threshold reference wave energy density of 0.6-0.8 mJ/cm2.

Color-tunable mixed photoluminescence emission from Alq3 organic layer in metal-Alq3-metal surface plasmon structure

OpenAIRE

Chen, Nai-Chuan; Liao, Chung-Chi; Chen, Cheng-Chang; Fan, Wan-Ting; Wu, Jin-Han; Li, Jung-Yu; Chen, Shih-Pu; Huang, Bohr-Ran; Lee, Li-Ling

2014-01-01

This work reports the color-tunable mixed photoluminescence (PL) emission from an Alq3 organic layer in an Au-Alq3-Au plasmonic structure through the combination of organic fluorescence emission and another form of emission that is enabled by the surface plasmons in the plasmonic structure. The emission wavelength of the latter depends on the Alq3 thickness and can be tuned within the Alq3 fluorescent spectra. Therefore, a two-color broadband, color-tunable mixed PL structure was obtained. Ob...

Human preferences for colorful birds: Vivid colors or pattern?

Science.gov (United States)

Lišková, Silvie; Landová, Eva; Frynta, Daniel

2015-04-29

In a previous study, we found that the shape of a bird, rather than its color, plays a major role in the determination of human preferences. Thus, in the present study, we asked whether the preferences of human respondents towards uniformly shaped, colorful birds are determined by pattern rather than color. The experimental stimuli were pictures of small passerine birds of the family Pittidae possessing uniform shape but vivid coloration. We asked 200 participants to rank 43 colored and 43 identical, but grayscaled, pictures of birds. To find the traits determining human preferences, we performed GLM analysis in which we tried to explain the mean preference ranks and PC axes by the following explanatory variables: the overall lightness and saturation, edges (pattern), and the portion of each of the basic color hues. The results showed that the mean preference ranks of the grayscale set is explained mostly by the birds' pattern, whereas the colored set ranking is mostly determined by the overall lightness. The effect of colors was weaker, but still significant, and revealed that people liked blue and green birds. We found no significant role of the color red, the perception of which was acquired relatively recently in evolution.

Human Preferences for Colorful Birds: Vivid Colors or Pattern?

Directory of Open Access Journals (Sweden)

Silvie Lišková

2015-04-01

Full Text Available In a previous study, we found that the shape of a bird, rather than its color, plays a major role in the determination of human preferences. Thus, in the present study, we asked whether the preferences of human respondents towards uniformly shaped, colorful birds are determined by pattern rather than color. The experimental stimuli were pictures of small passerine birds of the family Pittidae possessing uniform shape but vivid coloration. We asked 200 participants to rank 43 colored and 43 identical, but grayscaled, pictures of birds. To find the traits determining human preferences, we performed GLM analysis in which we tried to explain the mean preference ranks and PC axes by the following explanatory variables: the overall lightness and saturation, edges (pattern, and the portion of each of the basic color hues. The results showed that the mean preference ranks of the grayscale set is explained mostly by the birds' pattern, whereas the colored set ranking is mostly determined by the overall lightness. The effect of colors was weaker, but still significant, and revealed that people liked blue and green birds. We found no significant role of the color red, the perception of which was acquired relatively recently in evolution.

Plasmonic coaxial Fabry-Pérot nanocavity color filter

Science.gov (United States)

Si, G. Y.; Leong, E. S. P.; Danner, A. J.; Teng, J. H.

2010-08-01

Plamonic coaxial structures have drawn considerable attetion recently because of their unique properties. They exhibit different mechanisms of extraordinary optical transmission observed from subwavelength holes and they can support localized Fabry-Pérot plasmon modes. In this work, we experimentally demonstrate color filters based on coaxial structures fabricated in optically thick metallic films. Using nanogaps with different apertures from 160 nm down to only 40 nm, we show varying color outputs when the annular aperture arrays are illuminated with a broadband light source. Effective color-filter function is demonstrated in the optical regime. Different color outputs are observed and optical spectra are measured. In such structures, it is the propagating mode playing an important role rather than the evanescent. Resonances depend strongly on ring apertures, enabling devices with tunability of output colors using simple geometry control.

A model study on color and related structural properties of cured porcine batters

NARCIS (Netherlands)

Palombo, R.

1990-01-01

Color, determined by tristimulus colorimeters, and related structural properties, i.e., microstructure, surface rheology, and bulk rheology, of cured porcine meat batters were studied.

Effects of various processing factors (such as, temperature, air pressure during chopping, and

Modeling human color categorization: Color discrimination and color memory

OpenAIRE

Heskes, T.; van den Broek, Egon; Lucas, P.; Hendriks, Maria A.; Vuurpijl, L.G.; Puts, M.J.H.; Wiegerinck, W.

2003-01-01

Color matching in Content-Based Image Retrieval is done using a color space and measuring distances between colors. Such an approach yields non-intuitive results for the user. We introduce color categories (or focal colors), determine that they are valid, and use them in two experiments. The experiments conducted prove the difference between color categorization by the cognitive processes color discrimination and color memory. In addition, they yield a Color Look-Up Table, which can improve c...

The interaction between surface color and color knowledge: behavioral and electrophysiological evidence.

Science.gov (United States)

Bramão, Inês; Faísca, Luís; Forkstam, Christian; Inácio, Filomena; Araújo, Susana; Petersson, Karl Magnus; Reis, Alexandra

2012-02-01

In this study, we used event-related potentials (ERPs) to evaluate the contribution of surface color and color knowledge information in object identification. We constructed two color-object verification tasks - a surface and a knowledge verification task - using high color diagnostic objects; both typical and atypical color versions of the same object were presented. Continuous electroencephalogram was recorded from 26 subjects. A cluster randomization procedure was used to explore the differences between typical and atypical color objects in each task. In the color knowledge task, we found two significant clusters that were consistent with the N350 and late positive complex (LPC) effects. Atypical color objects elicited more negative ERPs compared to typical color objects. The color effect found in the N350 time window suggests that surface color is an important cue that facilitates the selection of a stored object representation from long-term memory. Moreover, the observed LPC effect suggests that surface color activates associated semantic knowledge about the object, including color knowledge representations. We did not find any significant differences between typical and atypical color objects in the surface color verification task, which indicates that there is little contribution of color knowledge to resolve the surface color verification. Our main results suggest that surface color is an important visual cue that triggers color knowledge, thereby facilitating object identification. Copyright © 2011 Elsevier Inc. All rights reserved.

7 CFR 29.3025 - General color.

Science.gov (United States)

2010-01-01

... General color. The color of tobacco considered in relation to the type as a whole. General color is distinguished from the restricted use of the term “color” within a group. It is basically related to body and... 7 Agriculture 2 2010-01-01 2010-01-01 false General color. 29.3025 Section 29.3025 Agriculture...

Study of chromatic adaptation using memory color matches, Part I: neutral illuminants.

Science.gov (United States)

Smet, Kevin A G; Zhai, Qiyan; Luo, Ming R; Hanselaer, Peter

2017-04-03

Twelve corresponding color data sets have been obtained using the long-term memory colors of familiar objects as target stimuli. Data were collected for familiar objects with neutral, red, yellow, green and blue hues under 4 approximately neutral illumination conditions on or near the blackbody locus. The advantages of the memory color matching method are discussed in light of other more traditional asymmetric matching techniques. Results were compared to eight corresponding color data sets available in literature. The corresponding color data was used to test several linear (von Kries, RLAB, etc.) and nonlinear (Hunt & Nayatani) chromatic adaptation transforms (CAT). It was found that a simple two-step von Kries, whereby the degree of adaptation D is optimized to minimize the DEu'v' prediction errors, outperformed all other tested models for both memory color and literature corresponding color sets, whereby prediction errors were lower for the memory color sets. The predictive errors were substantially smaller than the standard uncertainty on the average observer and were comparable to what are considered just-noticeable-differences in the CIE u'v' chromaticity diagram, supporting the use of memory color based internal references to study chromatic adaptation mechanisms.

Digital color acquisition, perception, coding and rendering

CERN Document Server

Fernandez-Maloigne, Christine; Macaire, Ludovic

2013-01-01

In this book the authors identify the basic concepts and recent advances in the acquisition, perception, coding and rendering of color. The fundamental aspects related to the science of colorimetry in relation to physiology (the human visual system) are addressed, as are constancy and color appearance. It also addresses the more technical aspects related to sensors and the color management screen. Particular attention is paid to the notion of color rendering in computer graphics. Beyond color, the authors also look at coding, compression, protection and quality of color images and videos.

Nonlinear dynamic modeling of a V-shaped metal based thermally driven MEMS actuator for RF switches

Science.gov (United States)

Bakri-Kassem, Maher; Dhaouadi, Rached; Arabi, Mohamed; Estahbanati, Shahabeddin V.; Abdel-Rahman, Eihab

2018-05-01

In this paper, we propose a new dynamic model to describe the nonlinear characteristics of a V-shaped (chevron) metallic-based thermally driven MEMS actuator. We developed two models for the thermal actuator with two configurations. The first MEMS configuration has a small tip connected to the shuttle, while the second configuration has a folded spring and a wide beam attached to the shuttle. A detailed finite element model (FEM) and a lumped element model (LEM) are proposed for each configuration to completely characterize the electro-thermal and thermo-mechanical behaviors. The nonlinear resistivity of the polysilicon layer is extracted from the measured current-voltage (I-V) characteristics of the actuator and the simulated corresponding temperatures in the FEM model, knowing the resistivity of the polysilicon at room temperature from the manufacture’s handbook. Both developed models include the nonlinear temperature-dependent material properties. Numerical simulations in comparison with experimental data using a dedicated MEMS test apparatus verify the accuracy of the proposed LEM model to represent the complex dynamics of the thermal MEMS actuator. The LEM and FEM simulation results show an accuracy ranging from a maximum of 13% error down to a minimum of 1.4% error. The actuator with the lower thermal load to air that includes a folded spring (FS), also known as high surface area actuator is compared to the actuator without FS, also known as low surface area actuator, in terms of the I-V characteristics, power consumption, and experimental static and dynamic responses of the tip displacement.

Color Fringe Correction by the Color Difference Prediction Using the Logistic Function.

Science.gov (United States)

Jang, Dong-Won; Park, Rae-Hong

2017-05-01

This paper proposes a new color fringe correction method that preserves the object color well by the color difference prediction using the logistic function. We observe two characteristics between normal edge (NE) and degraded edge (DE) due to color fringe: 1) the DE has relatively smaller R-G and B-G correlations than the NE and 2) the color difference in the NE can be fitted by the logistic function. The proposed method adjusts the color difference of the DE to the logistic function by maximizing the R-G and B-G correlations in the corrected color fringe image. The generalized logistic function with four parameters requires a high computational load to select the optimal parameters. In experiments, a one-parameter optimization can correct color fringe gracefully with a reduced computational load. Experimental results show that the proposed method restores well the original object color in the DE, whereas existing methods give monochromatic or distorted color.

Validation of color Doppler sonography for evaluating relative displacement between the flexor tendon and subsynovial connective tissue.

Science.gov (United States)

Tat, Jimmy; Kociolek, Aaron M; Keir, Peter J

2015-04-01

A common pathologic finding in carpal tunnel syndrome is fibrosis and thickening of the subsynovial connective tissue. This finding suggests an etiology of excessive shear forces, with relative longitudinal displacement between the flexor tendon and adjacent subsynovial connective tissue. The purpose of this study was to validate color Doppler sonography for measurement of tendon displacement over time. Eight unmatched fresh frozen cadaver arms were used to evaluate color Doppler sonography for measurement of tendon displacement. The middle flexor digitorum superficialis tendon was moved through a physiologic excursion of 20 mm at 3 different tendon velocities (50, 100, and 150 mm/s). We found that color Doppler sonography provided accurate measurement of tendon displacement, with absolute errors of -0.05 mm (50 mm/s), -1.24 mm (100 mm/s), and -2.36 mm (150 mm/s) on average throughout the tendon excursion range. Evaluating relative displacement between the tendon and subsynovial connective tissue during finger flexion-extension movements also offered insight into the gliding mechanism of the subsynovial connective tissue. During flexion, we observed a curvilinear increase in relative displacement, with greater differential motion at the end range of displacement, likely due to the sequential stretch of the fibrils between successive layers of the subsynovial connective tissue. In extension, there was a linear return in relative displacement, suggesting a different unloading mechanism characterized by uniform relaxation of fibrils. We demonstrated the validity of color Doppler displacement for use in the evaluation of relative motion. Color Doppler sonography is useful in our understanding of the behavior of the subsynovial connective tissue during tendon excursion, which may elucidate the role of finger motion in the etiology of shear injury. © 2015 by the American Institute of Ultrasound in Medicine.

Energy demand forecasting in Iranian metal industry using linear and nonlinear models based on evolutionary algorithms

International Nuclear Information System (INIS)

Piltan, Mehdi; Shiri, Hiva; Ghaderi, S.F.

2012-01-01

Highlights: ► Investigating different fitness functions for evolutionary algorithms in energy forecasting. ► Energy forecasting of Iranian metal industry by value added, energy prices, investment and employees. ► Using real-coded instead of binary-coded genetic algorithm decreases energy forecasting error. - Abstract: Developing energy-forecasting models is known as one of the most important steps in long-term planning. In order to achieve sustainable energy supply toward economic development and social welfare, it is required to apply precise forecasting model. Applying artificial intelligent models for estimation complex economic and social functions is growing up considerably in many researches recently. In this paper, energy consumption in industrial sector as one of the critical sectors in the consumption of energy has been investigated. Two linear and three nonlinear functions have been used in order to forecast and analyze energy in the Iranian metal industry, Particle Swarm Optimization (PSO) and Genetic Algorithms (GAs) are applied to attain parameters of the models. The Real-Coded Genetic Algorithm (RCGA) has been developed based on real numbers, which is introduced as a new approach in the field of energy forecasting. In the proposed model, electricity consumption has been considered as a function of different variables such as electricity tariff, manufacturing value added, prevailing fuel prices, the number of employees, the investment in equipment and consumption in the previous years. Mean Square Error (MSE), Root Mean Square Error (RMSE), Mean Absolute Deviation (MAD) and Mean Absolute Percent Error (MAPE) are the four functions which have been used as the fitness function in the evolutionary algorithms. The results show that the logarithmic nonlinear model using PSO algorithm with 1.91 error percentage has the best answer. Furthermore, the prediction of electricity consumption in industrial sector of Turkey and also Turkish industrial sector

Feedback from horizontal cells to cones mediates color induction and may facilitate color constancy in rainbow trout

NARCIS (Netherlands)

Sabbah, Shai; Zhu, Changhai; Hornsby, Mark A. W.; Kamermans, Maarten; Hawryshyn, Craig W.

2013-01-01

Color vision is most beneficial when the visual system is color constant and can correct the excitations of photoreceptors for differences in environmental irradiance. A phenomenon related to color constancy is color induction, where the color of an object shifts away from the color of its

Lysosome-related organelles as mediators of metal homeostasis.

Science.gov (United States)

Blaby-Haas, Crysten E; Merchant, Sabeeha S

2014-10-10

Metal ion assimilation is essential for all forms of life. However, organisms must properly control the availability of these nutrients within the cell to avoid inactivating proteins by mismetallation. To safeguard against an imbalance between supply and demand in eukaryotes, intracellular compartments contain metal transporters that load and unload metals. Although the vacuoles of Saccharomyces cerevisiae and Arabidopsis thaliana are well established locales for the storage of copper, zinc, iron, and manganese, related compartments are emerging as important mediators of metal homeostasis. Here we describe these compartments and review their metal transporter complement. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Nonlinear Dynamics of a Foil Bearing Supported Rotor System: Simulation and Analysis

Science.gov (United States)

Li, Feng; Flowers, George T.

1996-01-01

Foil bearings provide noncontacting rotor support through a number of thin metal strips attached around the circumference of a stator and separated from the rotor by a fluid film. The resulting support stiffness is dominated by the characteristics of the foils and is a nonlinear function of the rotor deflection. The present study is concerned with characterizing this nonlinear effect and investigating its influence on rotordynamical behavior. A finite element model is developed for an existing bearing, the force versus deflection relation characterized, and the dynamics of a sample rotor system are studied. Some conclusions are discussed with regard to appropriate ranges of operation for such a system.

Color preferences are not universal.

Science.gov (United States)

Taylor, Chloe; Clifford, Alexandra; Franklin, Anna

2013-11-01

Claims of universality pervade color preference research. It has been argued that there are universal preferences for some colors over others (e.g., Eysenck, 1941), universal sex differences (e.g., Hurlbert & Ling, 2007), and universal mechanisms or dimensions that govern these preferences (e.g., Palmer & Schloss, 2010). However, there have been surprisingly few cross-cultural investigations of color preference and none from nonindustrialized societies that are relatively free from the common influence of global consumer culture. Here, we compare the color preferences of British adults to those of Himba adults who belong to a nonindustrialized culture in rural Namibia. British and Himba color preferences are found to share few characteristics, and Himba color preferences display none of the so-called "universal" patterns or sex differences. Several significant predictors of color preference are identified, such as cone-contrast between stimulus and background (Hurlbert & Ling, 2007), the valence of color-associated objects (Palmer & Schloss, 2010), and the colorfulness of the color. However, the relationship of these predictors to color preference was strikingly different for the two cultures. No one model of color preference is able to account for both British and Himba color preferences. We suggest that not only do patterns of color preference vary across individuals and groups but the underlying mechanisms and dimensions of color preference vary as well. The findings have implications for broader debate on the extent to which our perception and experience of color is culturally relative or universally constrained. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Forty-five degree backscattering-mode nonlinear absorption imaging in turbid media.

Science.gov (United States)

Cui, Liping; Knox, Wayne H

2010-01-01

Two-color nonlinear absorption imaging has been previously demonstrated with endogenous contrast of hemoglobin and melanin in turbid media using transmission-mode detection and a dual-laser technology approach. For clinical applications, it would be generally preferable to use backscattering mode detection and a simpler single-laser technology. We demonstrate that imaging in backscattering mode in turbid media using nonlinear absorption can be obtained with as little as 1-mW average power per beam with a single laser source. Images have been achieved with a detector receiving backscattered light at a 45-deg angle relative to the incoming beams' direction. We obtain images of capillary tube phantoms with resolution as high as 20 microm and penetration depth up to 0.9 mm for a 300-microm tube at SNR approximately 1 in calibrated scattering solutions. Simulation results of the backscattering and detection process using nonimaging optics are demonstrated. A Monte Carlo-based method shows that the nonlinear signal drops exponentially as the depth increases, which agrees well with our experimental results. Simulation also shows that with our current detection method, only 2% of the signal is typically collected with a 5-mm-radius detector.

Image analysis of skin color heterogeneity focusing on skin chromophores and the age-related changes in facial skin.

Science.gov (United States)

Kikuchi, Kumiko; Masuda, Yuji; Yamashita, Toyonobu; Kawai, Eriko; Hirao, Tetsuji

2015-05-01

Heterogeneity with respect to skin color tone is one of the key factors in visual perception of facial attractiveness and age. However, there have been few studies on quantitative analyses of the color heterogeneity of facial skin. The purpose of this study was to develop image evaluation methods for skin color heterogeneity focusing on skin chromophores and then characterize ethnic differences and age-related changes. A facial imaging system equipped with an illumination unit and a high-resolution digital camera was used to develop image evaluation methods for skin color heterogeneity. First, melanin and/or hemoglobin images were obtained using pigment-specific image-processing techniques, which involved conversion from Commission Internationale de l'Eclairage XYZ color values to melanin and/or hemoglobin indexes as measures of their contents. Second, a spatial frequency analysis with threshold settings was applied to the individual images. Cheek skin images of 194 healthy Asian and Caucasian female subjects were acquired using the imaging system. Applying this methodology, the skin color heterogeneity of Asian and Caucasian faces was characterized. The proposed pigment-specific image-processing techniques allowed visual discrimination of skin redness from skin pigmentation. In the heterogeneity analyses of cheek skin color, age-related changes in melanin were clearly detected in Asian and Caucasian skin. Furthermore, it was found that the heterogeneity indexes of hemoglobin were significantly higher in Caucasian skin than in Asian skin. We have developed evaluation methods for skin color heterogeneity by image analyses based on the major chromophores, melanin and hemoglobin, with special reference to their size. This methodology focusing on skin color heterogeneity should be useful for better understanding of aging and ethnic differences. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Heavy metal concentrations in plants and different harvestable parts: A soil-plant equilibrium model

International Nuclear Information System (INIS)

Guala, Sebastian D.; Vega, Flora A.; Covelo, Emma F.

2010-01-01

A mathematical interaction model, validated by experimental results, was developed to modeling the metal uptake by plants and induced growth decrease, by knowing metal in soils. The model relates the dynamics of the uptake of metals from soil to plants. Also, two types of relationships are tested: total and available metal content. The model successfully fitted the experimental data and made it possible to predict the threshold values of total mortality with a satisfactory approach. Data are taken from soils treated with Cd and Ni for ryegrass (Lolium perenne, L.) and oats (Avena sativa L.), respectively. Concentrations are measured in the aboveground biomass of plants. In the latter case, the concentration of metals in different parts of the plants (tillering, shooting and earing) is also modeled. At low concentrations, the effects of metals are moderate, and the dynamics appear to be linear. However, increasing concentrations show nonlinear behaviors. - The model proposed in this study makes possible to characterize the nonlinear behavior of the soil-plant interaction with metal pollution.

Heavy metal concentrations in plants and different harvestable parts: A soil-plant equilibrium model

Energy Technology Data Exchange (ETDEWEB)

Guala, Sebastian D. [Instituto de Ciencias, Universidad Nacional de General Sarmiento, Gutierrez 1150, Los Polvorines, Buenos Aires (Argentina); Vega, Flora A. [Departamento de Bioloxia Vexetal e Ciencia do Solo, Facultade de Bioloxia, Universidade de Vigo, Lagoas, Marcosende, 36310 Vigo, Pontevedra (Spain); Covelo, Emma F., E-mail: emmaf@uvigo.e [Departamento de Bioloxia Vexetal e Ciencia do Solo, Facultade de Bioloxia, Universidade de Vigo, Lagoas, Marcosende, 36310 Vigo, Pontevedra (Spain)

2010-08-15

A mathematical interaction model, validated by experimental results, was developed to modeling the metal uptake by plants and induced growth decrease, by knowing metal in soils. The model relates the dynamics of the uptake of metals from soil to plants. Also, two types of relationships are tested: total and available metal content. The model successfully fitted the experimental data and made it possible to predict the threshold values of total mortality with a satisfactory approach. Data are taken from soils treated with Cd and Ni for ryegrass (Lolium perenne, L.) and oats (Avena sativa L.), respectively. Concentrations are measured in the aboveground biomass of plants. In the latter case, the concentration of metals in different parts of the plants (tillering, shooting and earing) is also modeled. At low concentrations, the effects of metals are moderate, and the dynamics appear to be linear. However, increasing concentrations show nonlinear behaviors. - The model proposed in this study makes possible to characterize the nonlinear behavior of the soil-plant interaction with metal pollution.

Metal-semiconductor interface in extreme temperature conditions

International Nuclear Information System (INIS)

Bulat, L.P.; Erofeeva, I.A.; Vorobiev, Yu.V.; Gonzalez-Hernandez, J.

2008-01-01

We present an investigation of electrons' and phonons' temperatures in the volume of a semiconductor (or metal) sample and at the interface between metal and semiconductor. Two types of mismatch between electrons' and phonons' temperatures take place: at metal-semiconductor interfaces and in the volume of the sample. The temperature mismatch leads to nonlinear terms in expressions for heat and electricity transport. The nonlinear effects should be taken into consideration in the study of electrical and heat transport in composites and in electronic chips

Nonlinear ultrasonics for material state awareness

Science.gov (United States)

Jacobs, L. J.

2014-02-01

Predictive health monitoring of structural components will require the development of advanced sensing techniques capable of providing quantitative information on the damage state of structural materials. By focusing on nonlinear acoustic techniques, it is possible to measure absolute, strength based material parameters that can then be coupled with uncertainty models to enable accurate and quantitative life prediction. Starting at the material level, this review will present current research that involves a combination of sensing techniques and physics-based models to characterize damage in metallic materials. In metals, these nonlinear ultrasonic measurements can sense material state, before the formation of micro- and macro-cracks. Typically, cracks of a measurable size appear quite late in a component's total life, while the material's integrity in terms of toughness and strength gradually decreases due to the microplasticity (dislocations) and associated change in the material's microstructure. This review focuses on second harmonic generation techniques. Since these nonlinear acoustic techniques are acoustic wave based, component interrogation can be performed with bulk, surface and guided waves using the same underlying material physics; these nonlinear ultrasonic techniques provide results which are independent of the wave type used. Recent physics-based models consider the evolution of damage due to dislocations, slip bands, interstitials, and precipitates in the lattice structure, which can lead to localized damage.

Understanding Colorism and How It Relates to Sport and Physical Education

Science.gov (United States)

Forster-Scott, Latisha

2011-01-01

Discrimination based on gradations of skin color can occur within and between racial or ethnic groups, including blacks, Latinos, and Asians. Lighter skin and Caucasian features tend to be viewed more positively than darker-skin qualities. Where a person of color falls along the "color line" may affect his or her social status, employment…

Toward efficient computation of the expected relative entropy for nonlinear experimental design

International Nuclear Information System (INIS)

Coles, Darrell; Prange, Michael

2012-01-01

The expected relative entropy between prior and posterior model-parameter distributions is a Bayesian objective function in experimental design theory that quantifies the expected gain in information of an experiment relative to a previous state of knowledge. The expected relative entropy is a preferred measure of experimental quality because it can handle nonlinear data-model relationships, an important fact due to the ubiquity of nonlinearity in science and engineering and its effects on post-inversion parameter uncertainty. This objective function does not necessarily yield experiments that mediate well-determined systems, but, being a Bayesian quality measure, it rigorously accounts for prior information which constrains model parameters that may be only weakly constrained by the optimized dataset. Historically, use of the expected relative entropy has been limited by the computing and storage requirements associated with high-dimensional numerical integration. Herein, a bifocal algorithm is developed that makes these computations more efficient. The algorithm is demonstrated on a medium-sized problem of sampling relaxation phenomena and on a large problem of source–receiver selection for a 2D vertical seismic profile. The method is memory intensive but workarounds are discussed. (paper)

ColorPhylo: A Color Code to Accurately Display Taxonomic Classifications.

Science.gov (United States)

Lespinats, Sylvain; Fertil, Bernard

2011-01-01

Color may be very useful to visualise complex data. As far as taxonomy is concerned, color may help observing various species' characteristics in correlation with classification. However, choosing the number of subclasses to display is often a complex task: on the one hand, assigning a limited number of colors to taxa of interest hides the structure imbedded in the subtrees of the taxonomy; on the other hand, differentiating a high number of taxa by giving them specific colors, without considering the underlying taxonomy, may lead to unreadable results since relationships between displayed taxa would not be supported by the color code. In the present paper, an automatic color coding scheme is proposed to visualise the levels of taxonomic relationships displayed as overlay on any kind of data plot. To achieve this goal, a dimensionality reduction method allows displaying taxonomic "distances" onto a Euclidean two-dimensional space. The resulting map is projected onto a 2D color space (the Hue, Saturation, Brightness colorimetric space with brightness set to 1). Proximity in the taxonomic classification corresponds to proximity on the map and is therefore materialised by color proximity. As a result, each species is related to a color code showing its position in the taxonomic tree. The so called ColorPhylo displays taxonomic relationships intuitively and can be combined with any biological result. A Matlab version of ColorPhylo is available at http://sy.lespi.free.fr/ColorPhylo-homepage.html. Meanwhile, an ad-hoc distance in case of taxonomy with unknown edge lengths is proposed.

The Universal Stellar Mass-Stellar Metallicity Relation for Dwarf Galaxies

OpenAIRE

Kirby, Evan N.; Cohen, Judith G.; Guhathakurta, Puragra; Cheng, Lucy; Bullock, James S.; Gallazzi, Anna

2013-01-01

We present spectroscopic metallicities of individual stars in seven gas-rich dwarf irregular galaxies (dIrrs), and we show that dIrrs obey the same massmetallicity relation as the dwarf spheroidal (dSph) satellites of both the Milky Way and M31: Z * σ M * 0.30±0. 02 . The uniformity of the relation is in contradiction to previous estimates of metallicity based on photometry. This relationship is roughly continuous with the stellar massstellar metallicity relation for galaxies as massive asM*...

Metallicity mapping of the Milky Way

Science.gov (United States)

Scowcroft, Vicky; Madore, Barry; Freedman, Wendy; Monson, Andy; Persson, Eric; Seibert, Mark; Rigby, Jane; Bersier, David; Stetson, Peter; Sturch, Laura

2011-05-01

We have discovered that the mid-infrared [3.6]-[4.5] colors of long-period Cepeids are dominated by a metallicity and temperature sensitive carbon monoxide feature that is squarely situated inside of the 4.5mu bandpass. The [3.6] photometry is unaffected by the CO and its PL relation can deliver distances to Cepheids that are individually good to ±4%. We will use the time-averaged 3.6um photometry of the 120 longest -period Galactic Cepheids to map the spiral structure of the Milky Way out to a radius 6 kpc around the solar neighborhood, and we will then use the [3.6]-[4.5] colors to derive spectroscopic-quality metallicities for each of these Cepheids. This will alow us to measure the radial gradient of metals in the galaxy and to explore its variance at fixed radius. For Cepheids with phased radial-velocity coverage we will for the first time apply the Baade-Wesselink methodology in the mid-infrared for determining the absolute luminosities (and distances) of these Cepheids. These determinations will greatly enhance the precision calibration of the slope, zero point and width of the Cepheid Period-Luminosity relation, well in advance of GAIA (whose nominal mission end is 2017). However, once GAIA has determined direct parallaxes to these same long-period Cepheids we will immediately be in a position to make the necessary intercomparisons and explore the physical consequences.

Juxtaposed color halftoning relying on discrete lines.

Science.gov (United States)

Babaei, Vahid; Hersch, Roger D

2013-02-01

Most halftoning techniques allow screen dots to overlap. They rely on the assumption that the inks are transparent, i.e., the inks do not scatter a significant portion of the light back to the air. However, many special effect inks, such as metallic inks, iridescent inks, or pigmented inks, are not transparent. In order to create halftone images, halftone dots formed by such inks should be juxtaposed, i.e., printed side by side. We propose an efficient juxtaposed color halftoning technique for placing any desired number of colorant layers side by side without overlapping. The method uses a monochrome library of screen elements made of discrete lines with rational thicknesses. Discrete line juxtaposed color halftoning is performed efficiently by multiple accesses to the screen element library.

HIDE-AND-SEEK WITH THE FUNDAMENTAL METALLICITY RELATION

Energy Technology Data Exchange (ETDEWEB)

Kashino, D. [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Nagoya, 464-8602 (Japan); Renzini, A. [INAF Osservatorio Astronomico di Padova, vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Silverman, J. D. [Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, the University of Tokyo, Kashiwanoha, Kashiwa, 277-8583 (Japan); Daddi, E., E-mail: daichi@nagoya-u.jp [Laboratoire AIM-Paris-Saclay, CEA/DSM-CNRS-Université Paris Diderot, Irfu/CEA-Saclay, Service d’Astrophysique, F-91191 Gif-sur-Yvette (France)

2016-06-01

We use ∼83,000 star-forming galaxies at 0.04 < z < 0.3 from the Sloan Digital Sky Survey to study the so-called fundamental metallicity relation (FMR) and report on the disappearance of its anti-correlation between metallicity and star formation rate (SFR) when using the new metallicity indicator recently proposed by Dopita et al. In this calibration, metallicity is primarily sensitive to the emission line ratio [N ii] λ 6584/[S ii] λλ 6717, 6731 that is insensitive to dilution by pristine infalling gas that may drive the FMR anti-correlation with SFR. Therefore, we conclude that the apparent disappearance of the FMR (using this new metallicity indicator) does not rule out its existence.

Color-Kinematics Duality for QCD Amplitudes

CERN Document Server

Johansson, Henrik

2016-01-01

We show that color-kinematics duality is present in tree-level amplitudes of quantum chromodynamics with massive flavored quarks. Starting with the color structure of QCD, we work out a new color decomposition for n-point tree amplitudes in a reduced basis of primitive amplitudes. These primitives, with k quark-antiquark pairs and (n-2k) gluons, are taken in the (n-2)!/k! Melia basis, and are independent under the color-algebra Kleiss-Kuijf relations. This generalizes the color decomposition of Del Duca, Dixon, and Maltoni to an arbitrary number of quarks. The color coefficients in the new decomposition are given by compact expressions valid for arbitrary gauge group and representation. Considering the kinematic structure, we show through explicit calculations that color-kinematics duality holds for amplitudes with general configurations of gluons and massive quarks. The new (massive) amplitude relations that follow from the duality can be mapped to a well-defined subset of the familiar BCJ relations for gluo...

Preferred memory color difference between the deuteranomalous and normal color vision

Science.gov (United States)

Baek, YeSeul; Kwak, Youngshin; Woo, Sungjoo; Park, Chongwook

2015-01-01

The goal of this study is to evaluate the difference of the preferred hues of familiar objects between the color deficient observer and the normal observer. Thirteen test color images were chosen covering fruit colors, natural scene and human faces. It contained red, yellow, green, blue, purple and skin color. Two color deficient observer (deuteranomal) and two normal observers were participated in this experiment. They controlled the YCC hue of the objects in the images to obtain the most preferred and the most natural image. The selected images were analyzed using CIELAB values of each pixel. Data analysis results showed that in the case of naturalness, both groups selected the similar hues for the most of image, while, in the case of preference, the color deficient observer preferred more reddish or more greenish images. Since the deuteranomalous observer has relatively week perception for red and green region, they may prefer more reddish or greenish color. The color difference between natural hue and preferred hue of deuteranomal observer is bigger than those of normal observer.

Elastic properties of Gum Metal

International Nuclear Information System (INIS)

Kuramoto, Shigeru; Furuta, Tadahiko; Hwang, Junghwan; Nishino, Kazuaki; Saito, Takashi

2006-01-01

In situ X-ray diffraction measurements under tensile loading and dynamic mechanical analysis were performed to investigate the mechanisms of elastic deformation in Gum Metal. Tensile stress-strain curves for Gum Metal indicate that cold working substantially decreases the elastic modulus while increasing the yield strength, thereby confirming nonlinearity in the elastic range. The gradient of each curve decreased continuously to about one-third its original value near the elastic limit. As a result of this decrease in elastic modulus and nonlinearity, elastic deformability reaches 2.5% after cold working. Superelasticity is attributed to stress-induced martensitic transformations, although the large elastic deformation in Gum Metal is not accompanied by a phase transformation

Poecilia picta, a Close Relative to the Guppy, Exhibits Red Male Coloration Polymorphism: A System for Phylogenetic Comparisons.

Directory of Open Access Journals (Sweden)

Anna K Lindholm

Full Text Available Studies on the evolution of female preference and male color polymorphism frequently focus on single species since traits and preferences are thought to co-evolve. The guppy, Poecilia reticulata, has long been a premier model for such studies because female preferences and orange coloration are well known to covary, especially in upstream/downstream pairs of populations. However, focused single species studies lack the explanatory power of the comparative method, which requires detailed knowledge of multiple species with known evolutionary relationships. Here we describe a red color polymorphism in Poecilia picta, a close relative to guppies. We show that this polymorphism is restricted to males and is maintained in natural populations of mainland South America. Using tests of female preference we show female P. picta are not more attracted to red males, despite preferences for red/orange in closely related species, such as P. reticulata and P. parae. Male color patterns in these closely related species are different from P. picta in that they occur in discrete patches and are frequently Y chromosome-linked. P. reticulata have an almost infinite number of male patterns, while P. parae males occur in discrete morphs. We show the red male polymorphism in P. picta extends continuously throughout the body and is not a Y-linked trait despite the theoretical prediction that sexually-selected characters should often be linked to the heterogametic sex chromosome. The presence/absence of red male coloration of P. picta described here makes this an ideal system for phylogenetic comparisons that could reveal the evolutionary forces maintaining mate choice and color polymorphisms in this speciose group.

Fabrication of full-color GaN-based light-emitting diodes on nearly lattice-matched flexible metal foils.

Science.gov (United States)

Kim, Hyeryun; Ohta, Jitsuo; Ueno, Kohei; Kobayashi, Atsushi; Morita, Mari; Tokumoto, Yuki; Fujioka, Hiroshi

2017-05-18

GaN-based light-emitting diodes (LEDs) have been widely accepted as highly efficient solid-state light sources capable of replacing conventional incandescent and fluorescent lamps. However, their applications are limited to small devices because their fabrication process is expensive as it involves epitaxial growth of GaN by metal-organic chemical vapor deposition (MOCVD) on single crystalline sapphire wafers. If a low-cost epitaxial growth process such as sputtering on a metal foil can be used, it will be possible to fabricate large-area and flexible GaN-based light-emitting displays. Here we report preparation of GaN films on nearly lattice-matched flexible Hf foils using pulsed sputtering deposition (PSD) and demonstrate feasibility of fabricating full-color GaN-based LEDs. It was found that introduction of low-temperature (LT) grown layers suppressed the interfacial reaction between GaN and Hf, allowing the growth of high-quality GaN films on Hf foils. We fabricated blue, green, and red LEDs on Hf foils and confirmed their normal operation. The present results indicate that GaN films on Hf foils have potential applications in fabrication of future large-area flexible GaN-based optoelectronics.

Modeling human color categorization: Color discrimination and color memory

NARCIS (Netherlands)

Heskes, T.; van den Broek, Egon; Lucas, P.; Hendriks, Maria A.; Vuurpijl, L.G.; Puts, M.J.H.; Wiegerinck, W.

2003-01-01

Color matching in Content-Based Image Retrieval is done using a color space and measuring distances between colors. Such an approach yields non-intuitive results for the user. We introduce color categories (or focal colors), determine that they are valid, and use them in two experiments. The

SPIDER. IV. OPTICAL AND NEAR-INFRARED COLOR GRADIENTS IN EARLY-TYPE GALAXIES: NEW INSIGHT INTO CORRELATIONS WITH GALAXY PROPERTIES

International Nuclear Information System (INIS)

La Barbera, F.; De Carvalho, R. R.; De La Rosa, I. G.; Gal, R. R.; Swindle, R.; Lopes, P. A. A.

2010-01-01

We present an analysis of stellar population gradients in 4546 early-type galaxies (ETGs) with photometry in grizYHJK along with optical spectroscopy. ETGs were selected as bulge-dominated systems, displaying passive spectra within the SDSS fibers. A new approach is described which utilizes color information to constrain age and metallicity gradients. Defining an effective color gradient, ∇ * , which incorporates all of the available color indices, we investigate how ∇ * varies with galaxy mass proxies, i.e., velocity dispersion, stellar (M * ) and dynamical (M dyn ) masses, as well as age, metallicity, and [α/Fe]. ETGs with M dyn larger than 8.5 x 10 10 M sun have increasing age gradients and decreasing metallicity gradients with respect to mass, metallicity, and enhancement. We find that velocity dispersion and [α/Fe] are the main drivers of these correlations. ETGs with 2.5 x 10 10 M sun ≤ M dyn ≤ 8.5 x 10 10 M sun show no correlation of age, metallicity, and color gradients with respect to mass, although color gradients still correlate with stellar population parameters, and these correlations are independent of each other. In both mass regimes, the striking anti-correlation between color gradient and α-enhancement is significant at ∼5σ and results from the fact that metallicity gradient decreases with [α/Fe]. This anti-correlation may reflect the fact that star formation and metallicity enrichment are regulated by the interplay between the energy input from supernovae, and the temperature and pressure of the hot X-ray gas in ETGs. For all mass ranges, positive age gradients are associated with old galaxies (>5-7 Gyr). For galaxies younger than ∼5 Gyr, mostly at low mass, the age gradient tends to be anti-correlated with the Age parameter, with more positive gradients at younger ages.

Fins coloration of perch in relation to external activity concentration of radionuclides

Energy Technology Data Exchange (ETDEWEB)

Yegoreichenkov, E.; Pryakhin, E. [Urals Research Center for Radiation Medicine (Russian Federation); Rudolfsen, G. [Norwegian Radiation Protection Authority and University of Tromsoe (Norway)

2014-07-01

The Techa River is significantly polluted by radionuclides. This time the content of {sup 90}Sr varies from 5 Bq/l in water of lower Techa to 40 Bq/l in higher Techa, and the concentration of {sup 137}Cs fluctuates from background content to 0,5 Bq/l, and tritium from 100 Bq/l to 450 Bq/l. Miass River are not polluted in the same extent. The perch in these rivers are suitable for examine the potential effect of environmental perturbation on carotenoid based coloration. As vertebrates could not produce carotenoids themselves, and would use more carotenoids due to oxidative stress when exposed radiation, we hypothesized that fish caught in upper part of Techa River will be more pale than fish from lower part and the control river Miass. We used a cost effective method to estimate coloration by photographing the fins in standardized setting. The measuring of fish fins as performed under standardized condition by Adobe Photoshop software in color spaces CIE 1976 L*a*b* and sRGB IEC61966-2.1 was used. In sRGB color space the values of Red, Green, Blue channels were measured and an average wave length was calculated as a function of three elementary light streams of different intensity, appeared as reflection from a fin. In L*a*b color space the values of *a and *b channels shows the position of a color in a color space. To evaluate the red color of a perch fin the most usable channel is the *a channel which shows the position of the color on the red-green axis. Due to low sample size we pooled males and females in our analysis. We used three different station in the Techa: RT-1 in the higher Techa, RT-2 in the middle Techa, and RT-3 in lower Techa. As a control group was taken the fish from Miass river (RM station). Our results shows that perch from RT-3 (570.7 nm) significantly differ in coloration from the perch from RT-2 and RT-1 (p=0.00001 and p=0.0014 respectively, hereinafter used Kruskal-Wallis rank sum test with Nemenyi-Damico-Wolfe-Dunn test as post

Color categories only affect post-perceptual processes when same- and different-category colors are equally discriminable.

Science.gov (United States)

He, Xun; Witzel, Christoph; Forder, Lewis; Clifford, Alexandra; Franklin, Anna

2014-04-01

Prior claims that color categories affect color perception are confounded by inequalities in the color space used to equate same- and different-category colors. Here, we equate same- and different-category colors in the number of just-noticeable differences, and measure event-related potentials (ERPs) to these colors on a visual oddball task to establish if color categories affect perceptual or post-perceptual stages of processing. Category effects were found from 200 ms after color presentation, only in ERP components that reflect post-perceptual processes (e.g., N2, P3). The findings suggest that color categories affect post-perceptual processing, but do not affect the perceptual representation of color.

Affective color palettes in visualization

OpenAIRE

Patra, Abhisekh

2017-01-01

The communication of affect, a feeling or emotion, has a central role in creating engaging visual experiences. Prior work on the psychology of color has focused on its effect on emotions, color preferences and reactions to color. Studies have attempted to solve problems related to improving aesthetics and emotions of images by improving color themes and templates. However, we have little understanding of how designers manipulate color properties for effective visual communication in informati...

Deep reduced PEDOT films support electrochemical applications: Biomimetic color front.

Directory of Open Access Journals (Sweden)

Toribio Fernandez OTERO

2015-02-01

Full Text Available Most of the literature accepts, despite many controversial results, that during oxidation/reduction films of conducting polymers move from electronic conductors to insulators. Thus, engineers and device’s designers are forced to use metallic supports to reoxidize the material for reversible device work. Electrochromic front experiments appear as main visual support of the claimed insulating nature of reduced conducting polymers. Here we present a different design of the biomimetic electrochromic front that corroborates the electronic and ionic conducting nature of deep reduced films. The direct contact PEDOT metal/electrolyte and film/electrolyte was prevented from electrolyte contact until 1cm far from the metal contact with protecting Parafilm®. The deep reduced PEDOT film supports the flow of high currents promoting reaction induced electrochromic color changes beginning 1 cm far from the metal-polymer electrical contact and advancing, through the reduced film, towards the metal contact. Reverse color changes during oxidation/reduction always are initiated at the film/electrolyte contact advancing, under the protecting film, towards the film/metal contact. Both reduced and oxidized states of the film demonstrate electronic and ionic conductivities high enough to be used for electronic applications or, as self-supported electrodes, for electrochemical devices. The electrochemically stimulated conformational relaxation (ESCR model explains those results.

Color guided amplitudes

Energy Technology Data Exchange (ETDEWEB)

Broedel, Johannes [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA (United States); Dixon, Lance J. [SLAC National Accelerator Laboratory, Stanford University, Stanford, CA (United States)

2012-07-01

Amplitudes in gauge thoeries obtain contributions from color and kinematics. While these two parts of the amplitude seem to exhibit different symmetry structures, it turns out that they can be reorganized in a way to behave equally, which leads to the so-called color-kinematic dual representations of amplitudes. Astonishingly, the existence of those representations allows squaring to related gravitational theories right away. Contrary to the Kawaii-Levellen-Tye relations, which have been used to relate gauge theories and gravity previously, this method is applicable not only to tree amplitudes but also at loop level. In this talk, the basic technique is introduced followed by a discussion of the existence of color-kinematic dual representations for amplitudes derived from gauge theory actions which are deformed by higher-operator insertions. In addition, it is commented on the implications for deformed gravitational theories.

Image color reduction method for color-defective observers using a color palette composed of 20 particular colors

Science.gov (United States)

Sakamoto, Takashi

2015-01-01

This study describes a color enhancement method that uses a color palette especially designed for protan and deutan defects, commonly known as red-green color blindness. The proposed color reduction method is based on a simple color mapping. Complicated computation and image processing are not required by using the proposed method, and the method can replace protan and deutan confusion (p/d-confusion) colors with protan and deutan safe (p/d-safe) colors. Color palettes for protan and deutan defects proposed by previous studies are composed of few p/d-safe colors. Thus, the colors contained in these palettes are insufficient for replacing colors in photographs. Recently, Ito et al. proposed a p/dsafe color palette composed of 20 particular colors. The author demonstrated that their p/d-safe color palette could be applied to image color reduction in photographs as a means to replace p/d-confusion colors. This study describes the results of the proposed color reduction in photographs that include typical p/d-confusion colors, which can be replaced. After the reduction process is completed, color-defective observers can distinguish these confusion colors.

Heavy metals and related trace elements

International Nuclear Information System (INIS)

Leland, H.V.; Luoma, S.N.; Wilkes, D.J.

1977-01-01

A review is given of heavy metals and related trace elements in the aquatic environment. Other reviews and bibliographies are cited, dealing with the metabolism and transport of metal ions and with the toxic effects of stable and radioactive trace metals on aquatic organisms. The sources of trace elements in natural waters are discussed. It is suggested that atmospheric inputs of several trace metals comprise sizable fractions of total inputs to the Great Lakes and continental shelf waters. Information on stack emissions of trace elements from a coal-fired steam plant was used to estimate the likely range of air concentrations and inputs to a forested watershed in Tennessee. Some basic concepts of cycling of elements through aquatic communities were examined, such as the Pb, Mn and Zn concentrations in sediment and estuarine plants and animals colonizing dredge-spoil disposal areas. The use of plants as biological indicators of trace element contamination was outlined, as well as bioaccumulation in aquatic fauna. The effects of environmental factors on the kinetics of element exchange were noted, for example the influx rates of Cs 137 in tubificid worms, and Co 60 and Zn 65 in shrimp were shown to be temperature dependent. The toxicity of heavy metals on aquatic fauna was discussed, such as the histopathological lesions in the kidney and liver of fishes caused by heavy metals, and the effects of Hg and Cu on the olfactory response of rainbow trout

Glass fiber-reinforced thermoplastics for use in metal-free removable partial dentures: combined effects of fiber loading and pigmentation on color differences and flexural properties.

Science.gov (United States)

Tanimoto, Yasuhiro; Nagakura, Manamu; Nishiyama, Norihiro

2018-02-21

The purpose of this study was to investigate the combined effects of fiber loading and pigmentation on the color differences and flexural properties of glass fiber-reinforced thermoplastics (GFRTPs), for use in non-metal clasp dentures (NMCDs). The GFRTPs consisted mainly of E-glass fibers, a polypropylene matrix, and a coloring pigment: the GFRTPs with various fiber loadings (0, 10, and 20mass%) and pigmentations (0, 1, 2, and 4mass%) were fabricated by using an injection molding. The color differences of GFRTPs were measured based on the Commission Internationale de l'Eclairage (CIE) Lab color system, by comparing with a commercially available NMCD. The flexural properties of GFRTPs were evaluated by using a three-point bending test, according to International Standards Organization (ISO) specification number 20795-1. The visible colors of GFRTPs with pigment contents of 2mass% were acceptable for gingival color, and the glass fibers harmonized well with the resins. The ΔE* values of the GFRTPs with pigment contents of 2mass% obtained by using the CIE Lab system were lowest at all fiber loadings. For GFRTPs with fiber contents of 10 and 20mass% at 2mass% pigment content, these GFRTPs surpassed the ISO 20795-1 specification regarding flexural strength (> 60MPa) and modulus (> 1.5GPa). A combination of the results of color difference evaluation and mechanical examination indicates that the GFRTPs with fiber contents of 10 or 20mass%, and with pigment contents of 2mass% have acceptable esthetic appearance and sufficient rigidity for NMCDs. Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

A synthesis of research on color, typography and graphics as they relate to readability

Science.gov (United States)

Lamoreaux, M. E.

1985-09-01

A foundation for future research on the use of color, typography, and graphics to improve readability is provided. Articles from the broad fields of education and psychology, as well as from the fields of journalism and printing, have been reviewed for research relating color, typography, and graphics to reading ease, speed, or comprehension. The most relevant articles reviewed are presented in an annoated bibliography; the remaining articles are also presented in bibliographic format. This literature review indicates that recognition and recall of printed material may be improved through the use of headings, underlining, color, and, especially, illustrations. Current research suggests that individuals can remember pictures far longer than past research indicates. However, researchers are divided on the usefulness of illustrations to improve reading comprehension. On the other hand, reading comprehension can be improved through the use of statistical graphs and tables if the reader is properly trained in the use of these devices.

Neural correlates of the classic color and emotional stroop in women with abuse-related posttraumatic stress disorder.

Science.gov (United States)

Bremner, J Douglas; Vermetten, Eric; Vythilingam, Meena; Afzal, Nadeem; Schmahl, Christian; Elzinga, Bernet; Charney, Dennis S

2004-03-15

The anterior cingulate and medial prefrontal cortex play an important role in the inhibition of responses, as measured by the Stroop task, as well as in emotional regulation. Dysfunction of the anterior cingulate/medial prefrontal cortex has been implicated in posttraumatic stress disorder (PTSD). The purpose of this study was to use the Stroop task as a probe of anterior cingulate function in PTSD. Women with early childhood sexual abuse-related PTSD (n = 12) and women with abuse but without PTSD (n = 9) underwent positron emission tomographic measurement of cerebral blood flow during exposure to control, color Stroop, and emotional Stroop conditions. Women with abuse with PTSD (but not abused non-PTSD women) had a relative decrease in anterior cingulate blood flow during exposure to the emotional (but not color) classic Stroop task. During the color Stroop there were also relatively greater increases in blood flow in non-PTSD compared with PTSD women in right visual association cortex, cuneus, and right inferior parietal lobule. These findings add further evidence for dysfunction of a network of brain regions, including anterior cingulate and visual and parietal cortex, in abuse-related PTSD.

Creep mechanisms and constitutive relations in pure metals

International Nuclear Information System (INIS)

Nix, W.D.

1979-01-01

The mechanisms of creep of pure metals is briefly reviewed and divided into two parts: steady state flow mechanisms, and non-steady state flow mechanisms and constitutive relations. Creep by diffusional flow is now reasonably well understood, with theory and experiment in good agreement. The closely related phenomenon of Harper--Dorn creep can also be understood in terms of diffusion between dislocations. Power law creep involves the climb of edge disloctions controlled by lattice self diffusion. Theoretical treatments of this process invariably give a power law exponent of 3. This natural creep law is compared with the data for FCC and BCC metals. It is suggested that diffusion controlled climb is the controlling process in BCC metals at very high temperatures. Stacking fault energy effects may preclude the possibility that creep is controlled entirely by lattice self diffusion in some FCC metals. The subject of power law breakdown is presented as a natural consequence of the transition to low temperature flow phenomena. The role of core diffusion in this transition is briefly discussed. The mechanisms are presented by which pure metals creep at elevated temperatures. While most of this review deals with the mechanisms of steady state flow, some discussion is devoted to creep flow under non-steady state conditions. This topic is discussed in connection with the development of constitutive equations for describing plastic flow in metals

Impurity-related linear and nonlinear optical response in quantum-well wires with triangular cross section

Energy Technology Data Exchange (ETDEWEB)

Duque, C.A., E-mail: cduque@fisica.udea.edu.co [Instituto de Física, Universidad de Antioquia, AA 1226, Medellín (Colombia); Mora-Ramos, M.E. [Instituto de Física, Universidad de Antioquia, AA 1226, Medellín (Colombia); Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Ave. Universidad 1001, CP 62209, Cuernavaca, Morelos, México (Mexico); Kasapoglu, E.; Ungan, F.; Yesilgul, U. [Cumhuriyet University, Physics Department, 58140 Sivas (Turkey); Sakiroglu, S. [Dokuz Eylül University, Physics Department, 35160 Buca, İzmir (Turkey); Sari, H. [Cumhuriyet University, Physics Department, 58140 Sivas (Turkey); Sökmen, I. [Dokuz Eylül University, Physics Department, 35160 Buca, İzmir (Turkey)

2013-11-15

The 1s-like and 2p-like donor impurity energy states are studied in a semiconductor quantum wire of equilateral triangular cross section as functions of the impurity position and the geometrical size of the structure. Linear and nonlinear coefficients for the optical absorption and relative refractive index change associated with 1s→2p transitions are calculated for both the x-polarization and y-polarization of the incident light. The results show a mixed effect of redshift and blueshift depending on the location of the donor atom. Also, strong nonlinear contributions to the optical absorption coefficient are obtained for both polarizations in the on-center impurity case. -- Highlights: • The 1s- and 2p-like impurity states in triangular quantum-well wires. • Optical absorption and relative refractive index changes are calculated. • Redshift and blueshift in the optical structures depend on the donor position. • Strong nonlinear contributions to the absorption coefficient have been obtained.

Effects of Nonlinear Absorption in BK7 and Color Glasses at 355 nm

International Nuclear Information System (INIS)

Adams, J J; McCarville, T; Bruere, J; McElroy, J; Peterson, J

2003-01-01

We have demonstrated a simple experimental technique that can be used to measure the nonlinear absorption coefficients in glasses. We determine BK7, UG1, and UG11 glasses to have linear absorption coefficients of 0.0217 ± 10% cm -1 , 1.7 ± 10% cm -1 , and 0.82 ± 10% cm -1 , respectively, two-photon absorption cross-sections of 0.025 ± 20% cm/GW, 0.035 ± 20% cm/GW, and 0.047 ± 20% cm/GW, respectively, excited-state absorption cross-sections of 8.0 x 10 -18 ± 20% cm 2 , 2.8 x 10 -16 ± 20% cm 2 , and 5 x 10 -17 ± 20% cm 2 , respectively, and solarization coefficients of 8.5 x 10 -20 ± 20% cm 2 , 2.5 x 10 -18 ± 20% cm 2 , and 1.3 x 10 -19 ± 20% cm 2 , respectively. For our application, nonlinear effects in 10-cm of BK7 are small ((le) 2%) for 355-nm fluences 2 for flat-top pulses. However, nonlinear effects are noticeable for 355-nm fluences at 0.8 J/cm 2 . In particular, we determine a 20% increase in the instantaneous absorption from linear, a solarization rate of 4% per 100 shots, and a 10% temporal droop introduced in the pulse, for 355-nm flat-top pulses at a fluence of 0.8 J/cm 2 . For 0.5-cm of UG1 absorbing glass the non-linear absorption has a similar effect as that from 10-cm of BK7 on the pulse shape; however, the effects in UG11 are much smaller

A universal color image quality metric

NARCIS (Netherlands)

Toet, A.; Lucassen, M.P.

2003-01-01

We extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated color space. The resulting color image quality index quantifies the distortion of a processed color image relative to its original version. We evaluated the new color image quality

Cobalt: for strength and color

Science.gov (United States)

Boland, Maeve A.; Kropschot, S.J.

2011-01-01

Cobalt is a shiny, gray, brittle metal that is best known for creating an intense blue color in glass and paints. It is frequently used in the manufacture of rechargeable batteries and to create alloys that maintain their strength at high temperatures. It is also one of the essential trace elements (or "micronutrients") that humans and many other living creatures require for good health. Cobalt is an important component in many aerospace, defense, and medical applications and is a key element in many clean energy technologies. The name cobalt comes from the German word kobold, meaning goblin. It was given this name by medieval miners who believed that troublesome goblins replaced the valuable metals in their ore with a substance that emitted poisonous fumes when smelted. The Swedish chemist Georg Brandt isolated metallic cobalt-the first new metal to be discovered since ancient times-in about 1735 and identified some of its valuable properties.

7 CFR 29.3508 - Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color. 29.3508 Section 29.3508 Agriculture Regulations... Type 95) § 29.3508 Color. The third factor of a grade based on the relative hues, saturations or chromas, and color values common to the type. ...

7 CFR 29.1005 - Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color. 29.1005 Section 29.1005 Agriculture Regulations... Type 92) § 29.1005 Color. The third factor of a grade based on the relative hues, saturations or chromas, and color values common to the type. ...

An event-related brain potential study of visual selective attention to conjunctions of color and shape

NARCIS (Netherlands)

Smid, HGOM; Jakob, A; Heinze, HJ

What cognitive processes underlie event-related brain potential (ERP) effects related to visual multidimensional selective attention and how are these processes organized? We recorded ERPs when participants attended to one conjunction of color, global shape and local shape and ignored other

Influence of Surrounding Colors in the Illuminant-Color Mode on Color Constancy

Directory of Open Access Journals (Sweden)

Kazuho Fukuda

2011-05-01

Full Text Available On color constancy, we showed that brighter surrounding colors had greater influence than dim colors (Uchikawa, Kitazawa, MacLeod, Fukuda, 2010 APCV. Increasing luminance of a stimulus causes the change in appearance from the surface-color to the illuminant-color mode. However it is unknown whether the visual system considers such color appearance mode of surrounding colors to achieve color constancy. We investigated the influence of surrounding colors that appeared illuminant on color constancy. The stimulus was composed of a central test stimulus and surrounding six colors: bright and dim red, green and blue. The observers adjusted the chromaticity of the test stimulus to be appeared as an achromatic surface. The luminance balance of three bright surrounding colors was equalized with that of the optimal colors in three illuminant conditions, then, the luminance of one of the three bright colors was varied in the range beyond the critical luminance of color appearance mode transition. The results showed that increasing luminance of a bright surrounding color shifted the observers' achromatic setting toward its chromaticity, but this effect diminished for the surrounding color in the illuminant-color mode. These results suggest that the visual system considers color appearance mode of surrounding colors to accomplish color constancy.

Experimental study of linear and nonlinear regimes of density-driven instabilities induced by CO2 dissolution in water

International Nuclear Information System (INIS)

Outeda, R.; D'Onofrio, A.; El Hasi, C.; Zalts, A.

2014-01-01

Density driven instabilities produced by CO 2 (gas) dissolution in water containing a color indicator were studied in a Hele Shaw cell. The images were analyzed and instability patterns were characterized by mixing zone temporal evolution, dispersion curves, and the growth rate for different CO 2 pressures and different color indicator concentrations. The results obtained from an exhaustive analysis of experimental data show that this system has a different behaviour in the linear regime of the instabilities (when the growth rate has a linear dependence with time), from the nonlinear regime at longer times. At short times using a color indicator to see the evolution of the pattern, the images show that the effects of both the color indicator and CO 2 pressure are of the same order of magnitude: The growth rates are similar and the wave numbers are in the same range (0–30 cm −1 ) when the system is unstable. Although in the linear regime the dynamics is affected similarly by the presence of the indicator and CO 2 pressure, in the nonlinear regime, the influence of the latter is clearly more pronounced than the effects of the color indicator

Color management with a hammer: the B-spline fitter

Science.gov (United States)

Bell, Ian E.; Liu, Bonny H. P.

2003-01-01

To paraphrase Abraham Maslow: If the only tool you have is a hammer, every problem looks like a nail. We have a B-spline fitter customized for 3D color data, and many problems in color management can be solved with this tool. Whereas color devices were once modeled with extensive measurement, look-up tables and trilinear interpolation, recent improvements in hardware have made B-spline models an affordable alternative. Such device characterizations require fewer color measurements than piecewise linear models, and have uses beyond simple interpolation. A B-spline fitter, for example, can act as a filter to remove noise from measurements, leaving a model with guaranteed smoothness. Inversion of the device model can then be carried out consistently and efficiently, as the spline model is well behaved and its derivatives easily computed. Spline-based algorithms also exist for gamut mapping, the composition of maps, and the extrapolation of a gamut. Trilinear interpolation---a degree-one spline---can still be used after nonlinear spline smoothing for high-speed evaluation with robust convergence. Using data from several color devices, this paper examines the use of B-splines as a generic tool for modeling devices and mapping one gamut to another, and concludes with applications to high-dimensional and spectral data.

A Non-linear "Inflation-Relative Prices Variability" Relationship: Evidence from Latin America

OpenAIRE

Mª Ángeles Caraballo Pou; Carlos Dabús; Diego Caramuta

2006-01-01

This paper presents evidence on a non-linear "inflation-relative prices variability" relationship in three Latin American countries with very high inflation experiences: Argentina, Brazil and Peru. More precisely, and in contrast to results found in previous literature for similar countries, we find a non-concave relation at higher inflation regimes, i.e. when inflation rate surpasses certain threshold. This non-concavity is mainly explained by the unexpected component of inflation, which sug...

7 CFR 29.3010 - Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color. 29.3010 Section 29.3010 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Color. The third factor of a grade, based on the relative hues, saturations or chroma, and color values...

Grapheme-color synesthesia can enhance immediate memory without disrupting the encoding of relational cues.

Science.gov (United States)

Gibson, Bradley S; Radvansky, Gabriel A; Johnson, Ann C; McNerney, M Windy

2012-12-01

Previous evidence has suggested that grapheme-color synesthesia can enhance memory for words, but little is known about how these photisms cue retrieval. Often, the encoding of specific features of individual words can disrupt the encoding of ordered relations between words, resulting in an overall decrease in recall accuracy. Here we show that the photisms arising from grapheme-color synesthesia do not function like these item-specific cues. The influences of high and low word frequency on the encoding of ordered relations and the accuracy of immediate free recall were compared across a group of 10 synesthetes and 48 nonsynesthetes. The main findings of Experiment 1 showed that the experience of synesthesia had no adverse effect on the encoding of ordered relations (as measured by input-output correspondence); furthermore, it enhanced recall accuracy in a strictly additive fashion across the two word frequency conditions. Experiment 2 corroborated these findings by showing that the synesthetes only outperformed the nonsynesthetes when the materials involved words and letters, not when they involved digits and spatial locations. Altogether, the present findings suggest that synesthesia can boost immediate memory performance without disrupting the encoding of ordered relations.

Metamaterial-Enhanced Nonlinear Terahertz Spectroscopy

Directory of Open Access Journals (Sweden)

Zhang X.

2013-03-01

Full Text Available We demonstrate large nonlinear terahertz responses in the gaps of metamaterial split ring resonators in several materials and use nonlinear THz transmission and THz-pump/THz-probe spectroscopy to study the nonlinear responses and dynamics. We use the field enhancement in the SRR gaps to initiate high-field phenomena at lower incident fields. In vanadium dioxide, we drive the insulator-to-metal phase transition with high-field THz radiation. The film conductivity increases by over two orders of magnitude and the phase transition occurs on a several picosecond timescale. In gallium arsenide, we observe high-field transport phenomena, including mobility saturation and impact ionization. The carrier density increases by up to ten orders of magnitude at high fields. At the highest fields, we demonstrate THz-induced damage in both vanadium dioxide and gallium arsenide.

Supervised feature selection for linear and non-linear regression of L⁎a⁎b⁎ color from multispectral images of meat

DEFF Research Database (Denmark)

Sharifzadeh, Sara; Clemmensen, Line Katrine Harder; Borggaard, Claus

2014-01-01

In food quality monitoring, color is an important indicator factor of quality. The CIELab (L⁎a⁎b⁎) color space as a device independent color space is an appropriate means in this case. The commonly used colorimeter instruments can neither measure the L⁎a⁎b color in a wide area over the target...

Eleven Colors That Are Almost Never Confused

Science.gov (United States)

Boynton, Robert M.

1989-08-01

1.1. Three functions of color vision. Setting aside the complex psychological effects of color, related to esthetics, fashion, and mood, three relatively basic functions of color vision, which can be examined scientifically, are discernable. (1) With the eye in a given state of adaptation, color vision allows the perception of signals that otherwise would be below threshold, and therefore lost to perception. Evidence for this comes from a variety of two-color threshold experiments. (2) Visible contours can be maintained by color differences alone, regardless of the relative radiances of the two parts of the field whose junction defines the border. For achromatic vision, contour disappears at the isoluminant point. (3) Color specifies what seems to be an absolute property of a surface, one that enhances its recognizability and allows a clearer separation and classification of non-contiguous elements in the visual field.

Preparation of Dithizone Functionalized Polystyrene for Detecting Heavy Metal Ion

Energy Technology Data Exchange (ETDEWEB)

Shin, Hyeon Ho; Kim, Younghun [Kwangwoon University, Seoul (Korea, Republic of)

2015-04-15

Colorimetric sensors were usually used to detect specific metal ions using selective color change of solutions. While almost organic dye in colorimetric sensors detected single molecule, dithizone (DTZ) solution could be separately detected above 5 kinds of heavy metal ions by the change of clear color. Namely, DTZ could be used as multicolorimetric sensors. However, DTZ was generally used as aqueous type and paper/pellet-type DTZ was not reported yet. Therefore, in this work, polystyrene (PS) was prepared to composite with DTZ and then DTZ/PS pellet was obtained, which was used to selectively detect 10 kinds of heavy metal ions. When 10 ppm of Hg and Co ions was exposed in DTZ/PS pellets, clear color change was revealed. It is noted that DTZ/PS pellet could be used in detecting of heavy metal ion as dry type.

INVESTIGATION OF THE METAL MELTING PROCESS

Directory of Open Access Journals (Sweden)

V. I. Timoshpolskij

2006-01-01

Full Text Available The nonlinear mathematical model of calculation of temperature fields in the process of metal melting is formulated and solved using the method of equivalent source taking into account nonlinearity of thermophysical properties of material and variable terms of heat exchange.

7 CFR 58.633 - Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Color. 58.633 Section 58.633 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections....633 Color. Coloring used for ice cream and related products shall be those certified by the U.S. Food...

Nonlinear generalization of the Kallen-Welton formula

International Nuclear Information System (INIS)

Kargin, A.Yu.

1982-01-01

Nonlinear dissipative-fluctuation relations permitting to find spectral correlation functions of (n+1) order for fluctuations of different electrodynamic values in plasma using the given value of tensor of nonlinear response of n order have been obtained for equilibrium plasma. At n=1 the relations obtained transform to the Kallen-Welton dissipative-fluctuation relation. Transformation of the nonlinear dissipative-fluctuation relation for cubical nonlinearity permitting to find nonlinear electric plasma susceptibility from the Known spectral correlation function of fourth order for charge density fluctUations in the absence of particle interaction is considered as an example. A compact expression for tensor of nonlinear plasma response has been obtained for an arbitrary order of nonlinearity

Tuning the dielectric properties of thiourea analog crystals for efficient nonlinear optical applications

International Nuclear Information System (INIS)

Sabari Girisun, T.C.; Dhanuskodi, S.

2010-01-01

Materials with low dielectric constant have attracted a great deal of interest in the field of nonlinear applications and microelectronic industry. Metal complexes of thiourea with group II transition metals (Zn, Cd) as central atom and period III elements (S, Cl) were synthesized by chemical reaction method and single crystals were grown from aqueous solution by slow evaporation method. By parallel plate capacitor technique, the dielectric response, dissipation factor, ac conductivity and impedance of virgin and metal complexes have been studied in the frequency (100 Hz to 5 MHz) and temperature (303-423 K) ranges. Metal complexes of thiourea with cadmium substitute have a low dielectric constant less than 10. Also the presence of chlorine in the metal complex induces noncentro symmetric structure. Hence the role of group II transition metals and period III elements in tuning the dielectric properties for efficient nonlinear applications has been studied.

Intelligent evaluation of color sensory quality of black tea by visible-near infrared spectroscopy technology: A comparison of spectra and color data information

Science.gov (United States)

Ouyang, Qin; Liu, Yan; Chen, Quansheng; Zhang, Zhengzhu; Zhao, Jiewen; Guo, Zhiming; Gu, Hang

2017-06-01

Instrumental test of black tea samples instead of human panel test is attracting massive attention recently. This study focused on an investigation of the feasibility for estimation of the color sensory quality of black tea samples using the VIS-NIR spectroscopy technique, comparing the performances of models based on the spectra and color information. In model calibration, the variables were first selected by genetic algorithm (GA); then the nonlinear back propagation-artificial neural network (BPANN) models were established based on the optimal variables. In comparison with the other models, GA-BPANN models from spectra data information showed the best performance, with the correlation coefficient of 0.8935, and the root mean square error of 0.392 in the prediction set. In addition, models based on the spectra information provided better performance than that based on the color parameters. Therefore, the VIS-NIR spectroscopy technique is a promising tool for rapid and accurate evaluation of the sensory quality of black tea samples.

ORIGIN OF THE GALAXY MASS-METALLICITY-STAR FORMATION RELATION

International Nuclear Information System (INIS)

Harwit, Martin; Brisbin, Drew

2015-01-01

We describe an equilibrium model that links the metallicity of low-redshift galaxies to stellar evolution models. It enables the testing of different stellar initial mass functions and metal yields against observed galaxy metallicities. We show that the metallicities of more than 80,000 Sloan Digital Sky Survey galaxies in the low-redshift range 0.07 ≤ z ≤ 0.3 considerably constrain stellar evolution models that simultaneously relate galaxy stellar mass, metallicity, and star formation rates to the infall rate of low-metallicity extragalactic gas and outflow of enriched matter. A feature of our model is that it encompasses both the active star forming phases of a galaxy and epochs during which the same galaxy may lie fallow. We show that the galaxy mass-metallicity-star formation relation can be traced to infall of extragalactic gas mixing with native gas from host galaxies to form stars of observed metallicities, the most massive of which eject oxygen into extragalactic space. Most consequential among our findings is that, on average, extragalactic infall accounts for one half of the gas required for star formation, a ratio that is remarkably constant across galaxies with stellar masses ranging at least from M* = 2 × 10 9 to 6 × 10 10 M ☉ . This leads us to propose that star formation is initiated when extragalactic infall roughly doubles the mass of marginally stable interstellar clouds. The processes described may also account quantitatively for the metallicity of extragalactic space, though to check this the fraction of extragalactic baryons will need to be more firmly established

ORIGIN OF THE GALAXY MASS-METALLICITY-STAR FORMATION RELATION

Energy Technology Data Exchange (ETDEWEB)

Harwit, Martin; Brisbin, Drew, E-mail: harwit@verizon.net [Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853 (United States)

2015-02-20

We describe an equilibrium model that links the metallicity of low-redshift galaxies to stellar evolution models. It enables the testing of different stellar initial mass functions and metal yields against observed galaxy metallicities. We show that the metallicities of more than 80,000 Sloan Digital Sky Survey galaxies in the low-redshift range 0.07 ≤ z ≤ 0.3 considerably constrain stellar evolution models that simultaneously relate galaxy stellar mass, metallicity, and star formation rates to the infall rate of low-metallicity extragalactic gas and outflow of enriched matter. A feature of our model is that it encompasses both the active star forming phases of a galaxy and epochs during which the same galaxy may lie fallow. We show that the galaxy mass-metallicity-star formation relation can be traced to infall of extragalactic gas mixing with native gas from host galaxies to form stars of observed metallicities, the most massive of which eject oxygen into extragalactic space. Most consequential among our findings is that, on average, extragalactic infall accounts for one half of the gas required for star formation, a ratio that is remarkably constant across galaxies with stellar masses ranging at least from M* = 2 × 10{sup 9} to 6 × 10{sup 10} M {sub ☉}. This leads us to propose that star formation is initiated when extragalactic infall roughly doubles the mass of marginally stable interstellar clouds. The processes described may also account quantitatively for the metallicity of extragalactic space, though to check this the fraction of extragalactic baryons will need to be more firmly established.

Tuning the Color of Silicon Nanostructures

KAUST Repository

Cao, Linyou

2010-07-14

Empowering silicon (Si) with optical functions constitutes a very important challenge in photonics. The scalable fabrication capabilities for this earth-abundant, environmentally friendly material are unmatched in sophistication and can be unleashed to realize a plethora of high-performance photonic functionalities that find application in information, bio-, display, camouflage, ornamental, and energy technologies. Nanofashioning represents a general strategy to turn Si into a useful optical material and Si structures have already been engineered to enable light emission, optical cloaking, waveguiding, nonlinear optics, enhanced light absorption, and sensing. Here, we demonstrate that a wide spectrum of colors can be generated by harnessing the strong resonant light scattering properties of Si nanostructures under white light illumination. The ability to engineer such colors in a predetermined fashion through a choice of the structure size, dielectric environment, and illumination conditions opens up entirely new applications of Si and puts this material in a new light. © 2010 American Chemical Society.

Filtering Non-Linear Transfer Functions on Surfaces.

Science.gov (United States)

Heitz, Eric; Nowrouzezahrai, Derek; Poulin, Pierre; Neyret, Fabrice

2014-07-01

Applying non-linear transfer functions and look-up tables to procedural functions (such as noise), surface attributes, or even surface geometry are common strategies used to enhance visual detail. Their simplicity and ability to mimic a wide range of realistic appearances have led to their adoption in many rendering problems. As with any textured or geometric detail, proper filtering is needed to reduce aliasing when viewed across a range of distances, but accurate and efficient transfer function filtering remains an open problem for several reasons: transfer functions are complex and non-linear, especially when mapped through procedural noise and/or geometry-dependent functions, and the effects of perspective and masking further complicate the filtering over a pixel's footprint. We accurately solve this problem by computing and sampling from specialized filtering distributions on the fly, yielding very fast performance. We investigate the case where the transfer function to filter is a color map applied to (macroscale) surface textures (like noise), as well as color maps applied according to (microscale) geometric details. We introduce a novel representation of a (potentially modulated) color map's distribution over pixel footprints using Gaussian statistics and, in the more complex case of high-resolution color mapped microsurface details, our filtering is view- and light-dependent, and capable of correctly handling masking and occlusion effects. Our approach can be generalized to filter other physical-based rendering quantities. We propose an application to shading with irradiance environment maps over large terrains. Our framework is also compatible with the case of transfer functions used to warp surface geometry, as long as the transformations can be represented with Gaussian statistics, leading to proper view- and light-dependent filtering results. Our results match ground truth and our solution is well suited to real-time applications, requires only a few

Color Gradients Within Globular Clusters: Restricted Numerical Simulation

Directory of Open Access Journals (Sweden)

Young-Jong Sohn

1997-06-01

Full Text Available The results of a restricted numerical simulation for the color gradients within globular clusters have been presented. The standard luminosity function of M3 and Salpeter's initial mass functions were used to generate model clusters as a fundamental population. Color gradients with the sample clusters for both King and power law cusp models of surface brightness distributions are discussed in the case of using the standard luminosity function. The dependence of color gradients on several parameters for the simulations with Salpeter's initial mass functions, such as slope of initial mass functions, cluster ages, metallicities, concentration parameters of King model, and slopes of power law, are also discussed. No significant radial color gradients are shown to the sample clusters which are regenerated by a random number generation technique with various parameters in both of King and power law cusp models of surface brightness distributions. Dynamical mass segregation and stellar evolution of horizontal branch stars and blue stragglers should be included for the general case of model simulations to show the observed radial color gradients within globular clusters.

What Is the Correct Answer about The Dress' Colors? Investigating the Relation between Optimism, Previous Experience, and Answerability.

Science.gov (United States)

Karlsson, Bodil S A; Allwood, Carl Martin

2016-01-01

The Dress photograph, first displayed on the internet in 2015, revealed stunning individual differences in color perception. The aim of this study was to investigate if lay-persons believed that the question about The Dress colors was answerable. Past research has found that optimism is related to judgments of how answerable knowledge questions with controversial answers are (Karlsson et al., 2016). Furthermore, familiarity with a question can create a feeling of knowing the answer (Reder and Ritter, 1992). Building on these findings, 186 participants saw the photo of The Dress and were asked about the correct answer to the question about The Dress' colors (" blue and black," "white and gold," "other, namely…," or "there is no correct answer" ). Choice of the alternative "there is no correct answer" was interpreted as believing the question was not answerable. This answer was chosen more often by optimists and by people who reported they had not seen The Dress before. We also found that among participants who had seen The Dress photo before, 19%, perceived The Dress as "white and gold" but believed that the correct answer was "blue and black ." This, in analogy to previous findings about non-believed memories (Scoboria and Pascal, 2016), shows that people sometimes do not believe the colors they have perceived are correct. Our results suggest that individual differences related to optimism and previous experience may contribute to if the judgment of the individual perception of a photograph is enough to serve as a decision basis for valid conclusions about colors. Further research about color judgments under ambiguous circumstances could benefit from separating individual perceptual experience from beliefs about the correct answer to the color question. Including the option "there is no correct answer " may also be beneficial.

Synesthesia for color is linked to improved color perception but reduced motion perception.

Science.gov (United States)

Banissy, Michael J; Tester, Victoria; Muggleton, Neil G; Janik, Agnieszka B; Davenport, Aimee; Franklin, Anna; Walsh, Vincent; Ward, Jamie

2013-12-01

Synesthesia is a rare condition in which one property of a stimulus (e.g., shape) triggers a secondary percept (e.g., color) not typically associated with the first. Work on synesthesia has predominantly focused on confirming the authenticity of synesthetic experience, but much less research has been conducted to examine the extent to which synesthesia is linked to broader perceptual differences. In the research reported here, we examined whether synesthesia is associated with differences in color and motion processing by comparing these abilities in synesthetes who experience color as their evoked sensation with nonsynesthetic participants. We show that synesthesia for color is linked to facilitated color sensitivity but decreased motion sensitivity. These findings are discussed in relation to the neurocognitive mechanisms of synesthesia and interactions between color and motion processing in typical adults.

Green function formalism for nonlinear acoustic waves in layered media

International Nuclear Information System (INIS)

Lobo, A.; Tsoy, E.; De Sterke, C.M.

2000-01-01

Full text: The applications of acoustic waves in identifying defects in adhesive bonds between metallic plates have received little attention at high intensities where the media respond nonlinearly. However, the effects of reduced bond strength are more distinct in the nonlinear response of the structure. Here we assume a weak nonlinearity acting as a small perturbation, thereby reducing the problem to a linear one. This enables us to develop a specialized Green function formalism for calculating acoustic fields in layered media

Heavy Metal Contamination of Popular Nail Polishes in Iran

Directory of Open Access Journals (Sweden)

Golnaz Karimi

2015-06-01

Full Text Available Background: Toxic and hazardous heavy metals like arsenic, lead, mercury, zinc, chromium and iron are found in a variety of personal care products, e.g. lipstick, whitening toothpaste, eyeliner and nail color. The nails absorb the pigments of nail polishes and vaporized or soluble metals can easily pass it. The goal of this survey was to assess whether the different colors of nail polishes comply with maximum concentrations of heavy metals in the EPA’s guidelines. Methods: 150 samples of different popular brands of nail polishes in 13 colors (yellow, beige, silver, pink, white, violet, brown, golden, green, black, colorless, red and blue were randomly purchased from beauty shops in Tehran City, Iran, in 2014. Microwave digestion EPA method 3051 was used by a microwave oven to determine the amount of 5 heavy metals; Nickel, Chromium, Lead, Arsenic and Cadmium. One-way ANOVA, Two-way ANOVA, hierarchical cluster, and principal component analyses were applied by Statistica 7.0 software. Results: The concentrations of chrome, lead, nickel and arsenic showed significant differences between the colors (p<0.05. In all studied samples, the level of cadmium was beyond the safe maximum permissible limit (MPS, but no significance difference in the cadmium content was identified. Conclusion: Due to the high concentrations of toxic metals in many brands of nail polishes, meticulous quality control is recommended for these beauty products.

A nonlinear model for AC induced corrosion

Directory of Open Access Journals (Sweden)

N. Ida

2012-09-01

Full Text Available The modeling of corrosion poses particular difficulties. The understanding of corrosion as an electrochemical process has led to simple capacitive-resistive models that take into account the resistance of the electrolytic cell and the capacitive effect of the surface potential at the interface between conductors and the electrolyte. In some models nonlinear conduction effects have been added to account for more complex observed behavior. While these models are sufficient to describe the behavior in systems with cathodic protection, the behavior in the presence of induced AC currents from power lines and from RF sources cannot be accounted for and are insufficient to describe the effects observed in the field. Field observations have shown that a rectifying effect exists that affects the cathodic protection potential and this effect is responsible for corrosion in the presence of AC currents. The rectifying effects of the metal-corrosion interface are totally missing from current models. This work proposes a nonlinear model based on finite element analysis that takes into account the nonlinear behavior of the metal-oxide interface and promises to improve modeling by including the rectification effects at the interface.

Color and behavior differently predict competitive outcomes for divergent stickleback color morphs

Science.gov (United States)

Lehto, Whitley R; Lierheimer, V Faith

2018-01-01

Abstract Our knowledge of how male competition contributes to speciation is dominated by investigations of competition between within-species morphs or closely related species that differ in conspicuous traits expressed during the breeding season (e.g. color, song). In such studies, it is important to consider the manner in which putatively sexually selected traits influence the outcome of competitive interactions within and between types because these traits can communicate information about competitor quality and may not be utilized by homotypic and heterotypic receivers in the same way. We studied the roles of breeding color and aggressive behaviors in competition within and between two divergent threespine stickleback Gasterosteus aculeatus color types. Our previous work in this system showed that the switch from red to black breeding coloration is associated with changes in male competition biases. Here, we find that red and black males also use different currencies in competition. Winners of both color types performed more aggressive behaviors than losers, regardless of whether the competitor was of the same or opposite color type. But breeding color differently predicted competitive outcomes for red and black males. Males who were redder at the start of competition were more likely to win when paired with homotypic competitors and less likely to win when paired with heterotypic competitors. In contrast, black color, though expressed in the breeding season and condition dependent, was unrelated to competitive outcomes. Placing questions about the role of male competition in speciation in a sexual signal evolution framework may provide insight into the “why and how” of aggression biases and asymmetries in competitive ability between closely related morphs and species. PMID:29492044

Ultrathin metal-semiconductor-metal resonator for angle invariant visible band transmission filters

International Nuclear Information System (INIS)

Lee, Kyu-Tae; Seo, Sungyong; Yong Lee, Jae; Jay Guo, L.

2014-01-01

We present transmission visible wavelength filters based on strong interference behaviors in an ultrathin semiconductor material between two metal layers. The proposed devices were fabricated on 2 cm × 2 cm glass substrate, and the transmission characteristics show good agreement with the design. Due to a significantly reduced light propagation phase change associated with the ultrathin semiconductor layer and the compensation in phase shift of light reflecting from the metal surface, the filters show an angle insensitive performance up to ±70°, thus, addressing one of the key challenges facing the previously reported photonic and plasmonic color filters. This principle, described in this paper, can have potential for diverse applications ranging from color display devices to the image sensors.

Properties of a color-changeable chewing gum used to evaluate masticatory performance.

Science.gov (United States)

Hama, Yohei; Kanazawa, Manabu; Minakuchi, Shunsuke; Uchida, Tatsuro; Sasaki, Yoshiyuki

2014-04-01

To clarify the basic properties of a color-changeable chewing gum to determine its applicability to evaluations of masticatory performance under different types of dental status. Ten participants with natural dentition aged 26-30 years chewed gum that changes color during several chewing strokes over five repetitions. Changes in color were assessed using a colorimeter, and then L*, a*, and b* values in the CIELAB color system were quantified. Relationships between chewing progression and color changes were assessed using regression analysis and the reliability of color changes was assessed using intraclass correlation coefficients. We then measured 42 dentate participants (age, 22-31 years) and 47 complete denture wearers (age, 44-90 years) to determine the detectability of masticatory performance under two types of dental status. Regression between the number of chewing strokes and the difference between two colors was non-linear. The intraclass correlation coefficients were highest between 60 and 160 chewing strokes. Dentate and edentulous groups significantly differed (Wilcoxon rank sum test) and values were widely distributed within each group. The color of the chewing gum changed over a wide range, which was sufficient to evaluate the masticatory performance of individuals with natural dentition and those with complete dentures. Changes in the color values of the gum reliably reflected masticatory performance. These findings indicate that the color-changeable chewing gum will be useful for evaluating masticatory performance under any dental status. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Synesthesia induced colors do not bias attention in the same manner as physical colors do

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik; Ásgeirsson, Árni Gunnar

2015-01-01

and performance in visual search, much like physical stimulus features. It has been demonstrated that the content of visual memory can guide attention (e.g. Carlisle & Woodman, 2011). This effect can be measured in the response time costs or benefits related to the presence of memorized color in a visual search......Grapheme-color synesthesia affects visual cognition in significant ways. The congruence or incongruence of physical stimuli with synesthetic color affects how quickly and accurately synesthetes respond to stimuli, and the induced color experience may help them memorize achromatic material...... display. Retaining color information in memory biases attention towards that specific color in visual search, apparent by response time costs when a matching distractor is present, but a benefit when the target matches the retained color. We investigated whether a synesthetic color is automatically...

Color metasurfaces in industrial perspective

DEFF Research Database (Denmark)

Højlund-Nielsen, Emil; Kristensen, Anders

This doctoral thesis describes the utilization of color metasurfaces in an industrial perspective, where nano-scale textures and contingent post processing replace inks, dyes and pigments in plastic production. The concept of colors by structure arguably reduces the number of raw materials......, exemplified in silicon. However, only corresponding faint colors appear in polymeric materials. The concept of all-polymer pigment-free coloration seems somewhat restricted in relation to widespread industrial employment. Finally, a novel plasmon color technology for structural coloration in plastics......, and it is shown that the dependence on polarization can be controlled. In collaboration with industry, polymer-based colored metasurfaces of square-centimeter size are demonstrated by embossing, injection molding, roll-to-roll printing, and film insert molding with full compatibility. Furthermore, post production...

Linear and ultrafast nonlinear plasmonics of single nano-objects

Science.gov (United States)

Crut, Aurélien; Maioli, Paolo; Vallée, Fabrice; Del Fatti, Natalia

2017-03-01

Single-particle optical investigations have greatly improved our understanding of the fundamental properties of nano-objects, avoiding the spurious inhomogeneous effects that affect ensemble experiments. Correlation with high-resolution imaging techniques providing morphological information (e.g. electron microscopy) allows a quantitative interpretation of the optical measurements by means of analytical models and numerical simulations. In this topical review, we first briefly recall the principles underlying some of the most commonly used single-particle optical techniques: near-field, dark-field, spatial modulation and photothermal microscopies/spectroscopies. We then focus on the quantitative investigation of the surface plasmon resonance (SPR) of metallic nano-objects using linear and ultrafast optical techniques. While measured SPR positions and spectral areas are found in good agreement with predictions based on Maxwell’s equations, SPR widths are strongly influenced by quantum confinement (or, from a classical standpoint, surface-induced electron scattering) and, for small nano-objects, cannot be reproduced using the dielectric functions of bulk materials. Linear measurements on single nano-objects (silver nanospheres and gold nanorods) allow a quantification of the size and geometry dependences of these effects in confined metals. Addressing the ultrafast response of an individual nano-object is also a powerful tool to elucidate the physical mechanisms at the origin of their optical nonlinearities, and their electronic, vibrational and thermal relaxation processes. Experimental investigations of the dynamical response of gold nanorods are shown to be quantitatively modeled in terms of modifications of the metal dielectric function enhanced by plasmonic effects. Ultrafast spectroscopy can also be exploited to unveil hidden physical properties of more complex nanosystems. In this context, two-color femtosecond pump-probe experiments performed on individual

Processing of Color Words Activates Color Representations

Science.gov (United States)

Richter, Tobias; Zwaan, Rolf A.

2009-01-01

Two experiments were conducted to investigate whether color representations are routinely activated when color words are processed. Congruency effects of colors and color words were observed in both directions. Lexical decisions on color words were faster when preceding colors matched the color named by the word. Color-discrimination responses…

Perception of color emotions for single colors in red-green defective observers.

Science.gov (United States)

Sato, Keiko; Inoue, Takaaki

2016-01-01

It is estimated that inherited red-green color deficiency, which involves both the protan and deutan deficiency types, is common in men. For red-green defective observers, some reddish colors appear desaturated and brownish, unlike those seen by normal observers. Despite its prevalence, few studies have investigated the effects that red-green color deficiency has on the psychological properties of colors (color emotions). The current study investigated the influence of red-green color deficiency on the following six color emotions: cleanliness, freshness, hardness, preference, warmth, and weight. Specifically, this study aimed to: (1) reveal differences between normal and red-green defective observers in rating patterns of six color emotions; (2) examine differences in color emotions related to the three cardinal channels in human color vision; and (3) explore relationships between color emotions and color naming behavior. Thirteen men and 10 women with normal vision and 13 men who were red-green defective performed both a color naming task and an emotion rating task with 32 colors from the Berkeley Color Project (BCP). Results revealed noticeable differences in the cleanliness and hardness ratings between the normal vision observers, particularly in women, and red-green defective observers, which appeared mainly for colors in the orange to cyan range, and in the preference and warmth ratings for colors with cyan and purple hues. Similarly, naming errors also mainly occurred in the cyan colors. A regression analysis that included the three cone-contrasts (i.e., red-green, blue-yellow, and luminance) as predictors significantly accounted for variability in color emotion ratings for the red-green defective observers as much as the normal individuals. Expressly, for warmth ratings, the weight of the red-green opponent channel was significantly lower in color defective observers than in normal participants. In addition, the analyses for individual warmth ratings in

Perception of color emotions for single colors in red-green defective observers

Directory of Open Access Journals (Sweden)

Keiko Sato

2016-12-01

Full Text Available It is estimated that inherited red-green color deficiency, which involves both the protan and deutan deficiency types, is common in men. For red-green defective observers, some reddish colors appear desaturated and brownish, unlike those seen by normal observers. Despite its prevalence, few studies have investigated the effects that red-green color deficiency has on the psychological properties of colors (color emotions. The current study investigated the influence of red-green color deficiency on the following six color emotions: cleanliness, freshness, hardness, preference, warmth, and weight. Specifically, this study aimed to: (1 reveal differences between normal and red-green defective observers in rating patterns of six color emotions; (2 examine differences in color emotions related to the three cardinal channels in human color vision; and (3 explore relationships between color emotions and color naming behavior. Thirteen men and 10 women with normal vision and 13 men who were red-green defective performed both a color naming task and an emotion rating task with 32 colors from the Berkeley Color Project (BCP. Results revealed noticeable differences in the cleanliness and hardness ratings between the normal vision observers, particularly in women, and red-green defective observers, which appeared mainly for colors in the orange to cyan range, and in the preference and warmth ratings for colors with cyan and purple hues. Similarly, naming errors also mainly occurred in the cyan colors. A regression analysis that included the three cone-contrasts (i.e., red-green, blue-yellow, and luminance as predictors significantly accounted for variability in color emotion ratings for the red-green defective observers as much as the normal individuals. Expressly, for warmth ratings, the weight of the red-green opponent channel was significantly lower in color defective observers than in normal participants. In addition, the analyses for individual warmth

On the Origin of the Mass-Metallicity Relation for GRB Host Galaxies

Energy Technology Data Exchange (ETDEWEB)

Kocevski, Daniel; /KIPAC, Menlo Park; West, Andrew A.; /Boston U., Dept. Astron.

2011-06-02

We investigate the nature of the mass-metallicity (M-Z) relation for long gamma-ray burst (LGRB) host galaxies. Recent studies suggest that the M-Z relation for local LGRB host galaxies may be systematically offset towards lower metallicities relative to the M-Z relation defined by the general star forming galaxy (SDSS) population. The nature of this offset is consistent with suggestions that low metallicity environments may be required to produce high mass progenitors, although the detection of several GRBs in high-mass, high-metallicity galaxies challenges the notion of a strict metallicity cut-off for host galaxies that are capable of producing GRBs. We show that the nature of this reported offset may be explained by a recently proposed anti-correlation between the star formation rate (SFR) and the metallicity of star forming galaxies. If low metallicity galaxies produce more stars than their equally massive, high-metallicity counterparts, then transient events that closely trace the SFR in a galaxy would be more likely to be found in these low metallicity, low mass galaxies. Therefore, the offset between the GRB and SDSS defined M-Z relations may be the result of the different methods used to select their respective galaxy populations, with GRBs being biased towards low metallicity, high SFR, galaxies. We predict that such an offset should not be expected of transient events that do not closely follow the star formation history of their host galaxies, such as short duration GRBs and SN Ia, but should be evident in core collapse SNe found through upcoming untargeted surveys.

Color categories and color appearance

Science.gov (United States)

Webster, Michael A.; Kay, Paul

2011-01-01

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue–green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue–green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses. PMID:22176751

7 CFR 29.2257 - Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color. 29.2257 Section 29.2257 Agriculture Regulations... INSPECTION Standards Official Standard Grades for Virginia Fire-Cured Tobacco (u.s. Type 21) § 29.2257 Color. The third factor of a grade based on the relative hues, saturation or chroma, and color values common...

7 CFR 29.2507 - Color.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Color. 29.2507 Section 29.2507 Agriculture Regulations...-Cured Tobacco (u.s. Types 22, 23, and Foreign Type 96) § 29.2507 Color. The third factor of a grade based on the relative hues, saturation or chroma, and color values common to the type. ...

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

Nonlinear and quantum optics near nanoparticles

Science.gov (United States)

Dhayal, Suman

We study the behavior of electric fields in and around dielectric and metal nanoparticles, and prepare the ground for their applications to a variety of systems viz. photovoltaics, imaging and detection techniques, and molecular spectroscopy. We exploit the property of nanoparticles being able to focus the radiation field into small regions and study some of the interesting nonlinear, and quantum coherence and interference phenomena near them. The traditional approach to study the nonlinear light-matter interactions involves the use of the slowly varying amplitude approximation (SVAA) as it simplifies the theoretical analysis. However, SVVA cannot be used for systems which are of the order of the wavelength of the light. We use the exact solutions of the Maxwell's equations to obtain the fields created due to metal and dielectric nanoparticles, and study nonlinear and quantum optical phenomena near these nanoparticles. We begin with the theoretical description of the electromagnetic fields created due to the nonlinear wavemixing process, namely, second-order nonlinearity in an nonlinear sphere. The phase-matching condition has been revisited in such particles and we found that it is not satisfied in the sphere. We have suggested a way to obtain optimal conditions for any type and size of material medium. We have also studied the modifications of the electromagnetic fields in a collection of nanoparticles due to strong near field nonlinear interactions using the generalized Mie theory for the case of many particles applicable in photovoltaics (PV). We also consider quantum coherence phenomena such as modification of dark states, stimulated Raman adiabatic passage (STIRAP), optical pumping in 4-level atoms near nanoparticles by using rotating wave approximation to describe the Hamiltonian of the atomic system. We also considered the behavior of atomic and the averaged atomic polarization in 7-level atoms near nanoparticles. This could be used as a prototype to study

Spin-current emission governed by nonlinear spin dynamics.

Science.gov (United States)

Tashiro, Takaharu; Matsuura, Saki; Nomura, Akiyo; Watanabe, Shun; Kang, Keehoon; Sirringhaus, Henning; Ando, Kazuya

2015-10-16

Coupling between conduction electrons and localized magnetization is responsible for a variety of phenomena in spintronic devices. This coupling enables to generate spin currents from dynamical magnetization. Due to the nonlinearity of magnetization dynamics, the spin-current emission through the dynamical spin-exchange coupling offers a route for nonlinear generation of spin currents. Here, we demonstrate spin-current emission governed by nonlinear magnetization dynamics in a metal/magnetic insulator bilayer. The spin-current emission from the magnetic insulator is probed by the inverse spin Hall effect, which demonstrates nontrivial temperature and excitation power dependences of the voltage generation. The experimental results reveal that nonlinear magnetization dynamics and enhanced spin-current emission due to magnon scatterings are triggered by decreasing temperature. This result illustrates the crucial role of the nonlinear magnon interactions in the spin-current emission driven by dynamical magnetization, or nonequilibrium magnons, from magnetic insulators.

Second-order nonlinear optical metamaterials: ABC-type nanolaminates

International Nuclear Information System (INIS)

Alloatti, L.; Kieninger, C.; Lauermann, M.; Köhnle, K.; Froelich, A.; Wegener, M.; Frenzel, T.; Freude, W.; Leuthold, J.; Koos, C.

2015-01-01

We demonstrate a concept for second-order nonlinear metamaterials that can be obtained from non-metallic centrosymmetric constituents with inherently low optical absorption. The concept is based on iterative atomic-layer deposition of three different materials, A = Al 2 O 3 , B = TiO 2 , and C = HfO 2 . The centrosymmetry of the resulting ABC stack is broken since the ABC and the inverted CBA sequences are not equivalent—a necessary condition for non-zero second-order nonlinearity. In our experiments, we find that the bulk second-order nonlinear susceptibility depends on the density of interfaces, leading to a nonlinear susceptibility of 0.26 pm/V at a wavelength of 800 nm. ABC-type nanolaminates can be deposited on virtually any substrate and offer a promising route towards engineering of second-order optical nonlinearities at both infrared and visible wavelengths

Color quarks and octonions

International Nuclear Information System (INIS)

Guersey, F.

1974-01-01

A mathematical framework based on octonions is developed for the description of the color quark scheme in which quarks are unobservable, the color SU(3) is exact, and only color singlets correspond to observable hadrons. The fictitious Hilbert space in which quarks operate is taken to be a space of vectors with octonion components. This space admits as a gauge group an exact SU(3) identified with the color SU/sub C/(3). Because of the nonassociativity of the underlying algebra, nonsinglet representations of SU/sub C/(3) are unobservable, while the subspace of color singlets satisfies associativity along with conditions for observability. Octonion quark fields satisfy the commutation relations of parafermions of order 3, leading to the correct SU(6) multiplets for hadrons. (U.S.)

Ultrahigh energy neutrinos and nonlinear QCD dynamics

International Nuclear Information System (INIS)

Machado, Magno V.T.

2004-01-01

The ultrahigh energy neutrino-nucleon cross sections are computed taking into account different phenomenological implementations of the nonlinear QCD dynamics. Based on the color dipole framework, the results for the saturation model supplemented by the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution as well as for the Balitskii-Fadin-Kuraev-Lipatov (BFKL) formalism in the geometric scaling regime are presented. They are contrasted with recent calculations using next-to-leading order DGLAP and unified BFKL-DGLAP formalisms

Evaluation of functional color vision requirements and current color vision screening tests for air traffic control specialists.

Science.gov (United States)

1990-08-01

An experiment was conducted to evaluate the relation of type and degree of color vision deficiency and aeromedical color vision screening test scores to performance of color-dependent tasks of Air Traffic Control Specialists. The subjects included 37...

Redox Conditions and Related Color Change in Eastern Equatorial Pacific Sediments: IODP Site U1334

Science.gov (United States)

Kordesch, W. E.; Gussone, N. C.; Hathorne, E. C.; Kimoto, K.; Delaney, M. L.

2011-12-01

This study was prompted by a 65 m thick brown-green color change in deep-sea sediments of IODP Site U1334 (0-38 Ma, 4799 m water depth) that corresponds to its equatorial crossing (caused by the Northward movement of the pacific plate). Green sediment is a visual indicator of reducing conditions in sediment due to enhanced organic matter deposition and burial. Here we use geochemical redox indicators to characterize the effect of equatorial upwelling on bottom water. The modern redox signal is captured in porewater profiles (nitrate, manganese, iron, sulfate) while trace metal Enrichment Factors (EF) in bulk sediment (manganese, uranium, molybdenum, rhenium) normalized to the detrital component (titanium) record redox state at burial. To measure export productivity we also measure biogenic barium. Porewater profiles reveal suboxic diagenesis; profiles follow the expected sequence of nitrate, manganese oxide, and iron oxide reduction with increasing depth. Constant sulfate (~28 μM) implies anoxia has not occurred. Bulk sediment Mn EF are enriched (EF > 1) throughout the record (Mn EF = 15-200) while U and Mo enrichment corresponds to green color and equatorial proximity (U EF = 4-19; Mo EF = 0-7). Constant Mn enrichment implies continuous oxygenation. Uranium and Mo enrichment near the equator represents suboxic conditions also seen in the porewater. Low Re concentrations (below detection) provide additional evidence against anoxia. A comparison of Mn EF from total digestions to samples treated with an additional reductive cleaning step distinguishes between Mn-oxides and Mn-carbonates, indicating oxygenated and reducing conditions respectively. Mn-carbonate occurrence agrees with U and Mo EF; conditions were more reducing near the equator. Bio-Ba shows significant variability over this interval (22-99 mmol g-1). Our geochemical results indicate that bottom waters became suboxic at the equator as a result of equatorial upwelling-influenced increases in organic

Preferred skin color enhancement for photographic color reproduction

Science.gov (United States)

Zeng, Huanzhao; Luo, Ronnier

2011-01-01

Skin tones are the most important colors among the memory color category. Reproducing skin colors pleasingly is an important factor in photographic color reproduction. Moving skin colors toward their preferred skin color center improves the color preference of skin color reproduction. Several methods to morph skin colors to a smaller preferred skin color region has been reported in the past. In this paper, a new approach is proposed to further improve the result of skin color enhancement. An ellipsoid skin color model is applied to compute skin color probabilities for skin color detection and to determine a weight for skin color adjustment. Preferred skin color centers determined through psychophysical experiments were applied for color adjustment. Preferred skin color centers for dark, medium, and light skin colors are applied to adjust skin colors differently. Skin colors are morphed toward their preferred color centers. A special processing is applied to avoid contrast loss in highlight. A 3-D interpolation method is applied to fix a potential contouring problem and to improve color processing efficiency. An psychophysical experiment validates that the method of preferred skin color enhancement effectively identifies skin colors, improves the skin color preference, and does not objectionably affect preferred skin colors in original images.

Nonlinear generalization of special relativity at very high energies

International Nuclear Information System (INIS)

Winterberg, F.

1984-01-01

It is shown, that the introduction of a fundamental length constant into the operator representation of the quantum mechanical commutation relations, as suggested by Bagge, leads to a nonlinear generalization of the Lorentz transformations. The theory requires the introduction of a substratum (ether) and which can be identified as the zero point vacuum energy. At very high energies a non-Lorentz invariant behaviour for the cross sections between elementary particles is predicted. Using the Einstein clock synchronisation definition, the velocity of light is also constant and equal to c in the new theory, but the zero point vacuum energy becomes finite, as are all other quantities which are divergent in Lorentz invariant quantum field theories. In the limiting case where the length constant is set equal to zero, the zero point vacuum energy diverges and special relativity is recovered. (orig.) [de

Nonlinear closure relations theory for transport processes in nonequilibrium systems

International Nuclear Information System (INIS)

Sonnino, Giorgio

2009-01-01

A decade ago, a macroscopic theory for closure relations has been proposed for systems out of Onsager's region. This theory is referred to as the thermodynamic field theory (TFT). The aim of this work was to determine the nonlinear flux-force relations that respect the thermodynamic theorems for systems far from equilibrium. We propose a formulation of the TFT where one of the basic restrictions, namely, the closed-form solution for the skew-symmetric piece of the transport coefficients, has been removed. In addition, the general covariance principle is replaced by the De Donder-Prigogine thermodynamic covariance principle (TCP). The introduction of TCP requires the application of an appropriate mathematical formalism, which is referred to as the entropy-covariant formalism. By geometrical arguments, we prove the validity of the Glansdorff-Prigogine universal criterion of evolution. A new set of closure equations determining the nonlinear corrections to the linear ('Onsager') transport coefficients is also derived. The geometry of the thermodynamic space is non-Riemannian. However, it tends to be Riemannian for high values of the entropy production. In this limit, we recover the transport equations found by the old theory. Applications of our approach to transport in magnetically confined plasmas, materials submitted to temperature, and electric potential gradients or to unimolecular triangular chemical reactions can be found at references cited herein. Transport processes in tokamak plasmas are of particular interest. In this case, even in the absence of turbulence, the state of the plasma remains close to (but, it is not in) a state of local equilibrium. This prevents the transport relations from being linear.

Simulated electron affinity tuning in metal-insulator-metal (MIM) diodes

Science.gov (United States)

Mistry, Kissan; Yavuz, Mustafa; Musselman, Kevin P.

2017-05-01

Metal-insulator-metal diodes for rectification applications must exhibit high asymmetry, nonlinearity, and responsivity. Traditional methods of improving these figures of merit have consisted of increasing insulator thickness, adding multiple insulator layers, and utilizing a variety of metal contact combinations. However, these methods have come with the price of increasing the diode resistance and ultimately limiting the operating frequency to well below the terahertz regime. In this work, an Airy Function Transfer Matrix simulation method was used to observe the effect of tuning the electron affinity of the insulator as a technique to decrease the diode resistance. It was shown that a small increase in electron affinity can result in a resistance decrease in upwards of five orders of magnitude, corresponding to an increase in operating frequency on the same order. Electron affinity tuning has a minimal effect on the diode figures of merit, where asymmetry improves or remains unaffected and slight decreases in nonlinearity and responsivity are likely to be greatly outweighed by the improved operating frequency of the diode.

Gender-related asymmetric brain vasomotor response to color stimulation: a functional transcranial Doppler spectroscopy study.

Science.gov (United States)

Njemanze, Philip C

2010-11-30

The present study was designed to examine the effects of color stimulation on cerebral blood mean flow velocity (MFV) in men and women. The study included 16 (8 men and 8 women) right-handed healthy subjects. The MFV was recorded simultaneously in both right and left middle cerebral arteries in Dark and white Light conditions, and during color (Blue, Yellow and Red) stimulations, and was analyzed using functional transcranial Doppler spectroscopy (fTCDS) technique. Color processing occurred within cortico-subcortical circuits. In men, wavelength-differencing of Yellow/Blue pairs occurred within the right hemisphere by processes of cortical long-term depression (CLTD) and subcortical long-term potentiation (SLTP). Conversely, in women, frequency-differencing of Blue/Yellow pairs occurred within the left hemisphere by processes of cortical long-term potentiation (CLTP) and subcortical long-term depression (SLTD). In both genders, there was luminance effect in the left hemisphere, while in men it was along an axis opposite (orthogonal) to that of chromatic effect, in women, it was parallel. Gender-related differences in color processing demonstrated a right hemisphere cognitive style for wavelength-differencing in men, and a left hemisphere cognitive style for frequency-differencing in women. There are potential applications of fTCDS technique, for stroke rehabilitation and monitoring of drug effects.

Correlation between ultrasonic nonlinearity and elastic nonlinearity in heat-treated aluminum alloy

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Beom; Jhang, Kyung Young [Hanyang University, Seoul (Korea, Republic of)

2017-04-15

The nonlinear ultrasonic technique is a potential nondestructive method to evaluate material degradation, in which the ultrasonic nonlinearity parameter is usually measured. The ultrasonic nonlinearity parameter is defined by the elastic nonlinearity coefficients of the nonlinear Hooke’s equation. Therefore, even though the ultrasonic nonlinearity parameter is not equal to the elastic nonlinearity parameter, they have a close relationship. However, there has been no experimental verification of the relationship between the ultrasonic and elastic nonlinearity parameters. In this study, the relationship is experimentally verified for a heat-treated aluminum alloy. Specimens of the aluminum alloy were heat-treated at 300°C for different periods of time (0, 1, 2, 5, 10, 20, and 50 h). The relative ultrasonic nonlinearity parameter of each specimen was then measured, and the elastic nonlinearity parameter was determined by fitting the stress-strain curve obtained from a tensile test to the 5th-order-polynomial nonlinear Hooke’s equation. The results showed that the variations in these parameters were in good agreement with each other.

CE of phytosiderophores and related metal species in plants.

Science.gov (United States)

Xuan, Yue; Scheuermann, Enrico B; Meda, Anderson R; Jacob, Peter; von Wirén, Nicolaus; Weber, Günther

2007-10-01

Phytosiderophores (PS) and the closely related substance nicotianamine (NA) are key substances in metal uptake into graminaceous plants. Here, the CE separation of these substances and related metal species is demonstrated. In particular, the three PS 2'-deoxymugineic acid (DMA), mugineic acid (MA), and 3-epi-hydroxymugineic acid (epi-HMA), and NA, are separated using MES/Tris buffer at pH 7.3. Moreover, three Fe(III) species of the different PS are separated without any stability problems, which are often present in chromatographic analyses. Also divalent metal species of Cu, Ni, and Zn with the ligands DMA and NA are separated with the same method. By using a special, zwitterionic CE capillary, even the separation of two isomeric Fe(III) chelates with the ligand ethylenediamine-N,N'-bis(o-hydroxyphenyl)acetic acid (EDDHA) is possible (i.e., meso-Fe(III)-EDDHA and rac-Fe(III)-EDDHA), and for fast separations of NA and respective divalent and trivalent metal species, a polymer CE microchip with suppressed EOF is described. The proposed CE method is applicable to real plant samples, and enables to detect changes of metal species (Cu-DMA, Ni-NA), which are directly correlated to biological processes.

Ablation and optical third-order nonlinearities in Ag nanoparticles

Directory of Open Access Journals (Sweden)

Carlos Torres-Torres

2010-11-01

Full Text Available Carlos Torres-Torres1, Néstor Peréa-López2, Jorge Alejandro Reyes-Esqueda3, Luis Rodríguez-Fernández3, Alejandro Crespo-Sosa3, Juan Carlos Cheang-Wong3, Alicia Oliver31Section of Graduate Studies and Research, School of Mechanical and Electrical Engineering, National Polytechnic Institute, Zacatenco, Distrito Federal, Mexico; 2Laboratory for Nanoscience and Nanotechnology Research and Advanced Materials Department, IPICYT, Camino a la Presa San Jose, San Luis Potosi, Mexico; 3Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, México, D.F. 01000, MéxicoAbstract: The optical damage associated with high intensity laser excitation of silver nanoparticles (NPs was studied. In order to investigate the mechanisms of optical nonlinearity of a nanocomposite and their relation with its ablation threshold, a high-purity silica sample implanted with Ag ions was exposed to different nanosecond and picosecond laser irradiations. The magnitude and sign of picosecond refractive and absorptive nonlinearities were measured near and far from the surface plasmon resonance (SPR of the Ag NPs with a self-diffraction technique. Saturable optical absorption and electronic polarization related to self-focusing were identified. Linear absorption is the main process involved in nanosecond laser ablation, but nonlinearities are important for ultrashort picosecond pulses when the absorptive process become significantly dependent on the irradiance. We estimated that near the resonance, picosecond intraband transitions allow an expanded distribution of energy among the NPs, in comparison to the energy distribution resulting in a case of far from resonance, when the most important absorption takes place in silica. We measured important differences in the ablation threshold and we estimated that the high selectiveness of the SPR of Ag NPs as well as their corresponding optical nonlinearities can be strongly significant for laser

Electrically and chemically tunable soft-solid block copolymer structural color (Conference Presentation)

Science.gov (United States)

Park, Cheolmin

2016-09-01

1D photonic crystals based on the periodic stacking of two different dielectric layers have been widely studied due to their potential use in low-power reflective mode displays, e-books and sensors, but the fabrication of mechanically flexible polymer structural color (SC) films, with electro-active color switching, remains challenging. Here, we demonstrate free-standing electric field tunable ionic liquid swollen block copolymer films. Placement of a polymer/ionic liquid (IL) film-reservoir adjacent to a self-assembled poly(styrene-block-quaternized 2vinyl pyridine) (PS-b-QP2VP) copolymer SC film allowed the development of R, G and B full-color SC block copolymer films by swelling of the QP2VP domains by the ionic liquid associated with water molecules. The IL-polymer/BCP SC film is mechanically flexible with excellent color stability over several days at ambient conditions. The selective swelling of the QP2VP domains could be controlled by both the ratio of the IL to a polymer in the gel-like IL reservoir layer and by an applied voltage in the range of -3V to +6V using a metal/IL reservoir/SC film/IL reservoir/metal capacitor type device.

A study on compound contents for plastic injection molding products of metallic resin pigment

International Nuclear Information System (INIS)

Park, Young Whan; Kwak, Jae Seob; Lee, Gyu Sang

2016-01-01

Injection molding process is widely used for producing most plastic products. In order to make a metal-colored plastic product especially in modern luxury home alliances, metallic pigments which are mixed to a basic resin material for injection molding are available. However, the process control for the metal-colored plastic product is extremely difficult due to non-uniform melt flow of the metallic resin pigments. To improve the process efficiency, a rapid mold cooling method by a compressed cryogenic fluid and electricity mold are also proposed to decrease undesired compound contents within a molded plastic product. In this study, a quality of the metal-colored plastic product is evaluated with process parameters; injection speed, injection pressure, and pigment contents, and an influence of the rapid cooling and heating system is demonstrated

A study on compound contents for plastic injection molding products of metallic resin pigment

Energy Technology Data Exchange (ETDEWEB)

Park, Young Whan; Kwak, Jae Seob [Dept. of Mechanical Engineering, Pukyong National University, Busan (Korea, Republic of); Lee, Gyu Sang [Alliance Molding Engineering TeamLG Electronics Inc., Osan (Korea, Republic of)

2016-12-15

Injection molding process is widely used for producing most plastic products. In order to make a metal-colored plastic product especially in modern luxury home alliances, metallic pigments which are mixed to a basic resin material for injection molding are available. However, the process control for the metal-colored plastic product is extremely difficult due to non-uniform melt flow of the metallic resin pigments. To improve the process efficiency, a rapid mold cooling method by a compressed cryogenic fluid and electricity mold are also proposed to decrease undesired compound contents within a molded plastic product. In this study, a quality of the metal-colored plastic product is evaluated with process parameters; injection speed, injection pressure, and pigment contents, and an influence of the rapid cooling and heating system is demonstrated.

Metallicity of Young and Old Stars in Irregular Galaxies

Science.gov (United States)

Tikhonov, N. A.

2018-01-01

Based on archived images obtained with the Hubble Space Telescope, stellar photometry for 105 irregular galaxies has been conducted. We have shown the red supergiant and giant branches in the obtained Hertzsprung-Russel diagrams. Using the TRGB method, distances to galaxies and metallicity of red giants have been determined. The color index ( V - I) of the supergiant branch at the luminosity level M I = -7 was chosen as the metallicity index of red supergiants. For the galaxies under study, the diagrams have been built, in which the correlation can be seen between the luminosity of galaxies ( M B ) and metallicity of red giants and supergiants. The main source of variance of the results in the obtained diagrams is, in our opinion, uncertainty inmeasurements of galaxy luminosities and star-forming outburst. The relation between metallicity of young and old stars shows that main enrichment of galaxies with metals has taken place in the remote past. Deviations of some galaxies in the obtained relation can possibly be explained with the fall of the intergalactic gas on them, although, this inconsiderably affects metallicities of the stellar content.

Implications of the dwarfs spheroidal galaxy mass-metallicity relation

International Nuclear Information System (INIS)

Smith, G.H.

1985-01-01

The properties of the mass-metallicity relation among dwarf spheroidal galaxies are discussed in terms of a model which assumes that the internal chemical evolution of the dwarf spheroidals was promoted by supernova activity. The model can be used to explain the observed dwarf spheroidal mass-metallicity relation assuming the present mass of these systems M sub s is proportional to their initial masses M as M sub s varies according to a power-law index of exp 7/4. It is inferred from the power-law dependence of M on the proto-cloud radius that the most massive dwarf spheroids were formed from the densest clouds. The observed slope of the mass-metallicity relation for dwarf spheroidal galaxies is found to be significantly different from theoretical estimates of this slope for elliptical galaxies. It is suggested that the difference may imply that spheroidal dwarfs and elliptical galaxies had different formation histories, confirming Kormendy's (1985) observations of differences in the brightness and luminosity trends. 54 references

Colored Contact Lens Dangers

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Full Text Available ... eye-care team . Consumer warning about the improper use of colored contact lenses , from the U.S. Food and Drug Administration (FDA). Are the colored lenses you are considering buying approved by the FDA? Check the FDA's database of approved contact lenses . Related Stories Prevent Infection ...

Using color management in color document processing

Science.gov (United States)

Nehab, Smadar

1995-04-01

Color Management Systems have been used for several years in Desktop Publishing (DTP) environments. While this development hasn't matured yet, we are already experiencing the next generation of the color imaging revolution-Device Independent Color for the small office/home office (SOHO) environment. Though there are still open technical issues with device independent color matching, they are not the focal point of this paper. This paper discusses two new and crucial aspects in using color management in color document processing: the management of color objects and their associated color rendering methods; a proposal for a precedence order and handshaking protocol among the various software components involved in color document processing. As color peripherals become affordable to the SOHO market, color management also becomes a prerequisite for common document authoring applications such as word processors. The first color management solutions were oriented towards DTP environments whose requirements were largely different. For example, DTP documents are image-centric, as opposed to SOHO documents that are text and charts centric. To achieve optimal reproduction on low-cost SOHO peripherals, it is critical that different color rendering methods are used for the different document object types. The first challenge in using color management of color document processing is the association of rendering methods with object types. As a result of an evolutionary process, color matching solutions are now available as application software, as driver embedded software and as operating system extensions. Consequently, document processing faces a new challenge, the correct selection of the color matching solution while avoiding duplicate color corrections.

A NEW SCALING RELATION FOR H II REGIONS IN SPIRAL GALAXIES: UNVEILING THE TRUE NATURE OF THE MASS-METALLICITY RELATION

Energy Technology Data Exchange (ETDEWEB)

Rosales-Ortega, F. F.; Diaz, A. I. [Departamento de Fisica Teorica, Universidad Autonoma de Madrid, E-28049 Madrid (Spain); Sanchez, S. F.; Iglesias-Paramo, J.; Vilchez, J. M.; Mast, D. [Instituto de Astrofisica de Andalucia (CSIC), Camino Bajo de Huetor s/n, Aptdo. 3004, E-18080 Granada (Spain); Bland-Hawthorn, J. [Sydney Institute for Astronomy, School of Physics A28, University of Sydney, NSW 2006 (Australia); Husemann, B., E-mail: frosales@cantab.net [Leibniz-Institut fuer Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)

2012-09-10

We demonstrate the existence of a local mass, metallicity, star formation relation using spatially resolved optical spectroscopy of H II regions in the local universe. One of the projections of this distribution-the local mass-metallicity relation-extends over a wide range in this parameter space: three orders of magnitude in mass and a factor of eight in metallicity. We explain the new relation as the combined effect of the differential distributions of mass and metallicity in the disks of galaxies, and a selective star formation efficiency. We use this local relation to reproduce-with a noticeable agreement-the mass-metallicity relation seen in galaxies, and conclude that the latter is a scale-up integrated effect of a local relation, supporting the inside-out growth and downsizing scenarios of galaxy evolution.

IMF–METALLICITY: A TIGHT LOCAL RELATION REVEALED BY THE CALIFA SURVEY

International Nuclear Information System (INIS)

Martín-Navarro, Ignacio; Vazdekis, Alexandre; Falcón-Barroso, Jesús; La Barbera, Francesco; Lyubenova, Mariya; Trager, S. C.; Ven, Glenn van de; Ferreras, Ignacio; Sánchez, S. F.; García-Benito, R.; Mendoza, M. A.; Mast, D.; Sánchez-Blázquez, P.

2015-01-01

Variations in the stellar initial mass function (IMF) have been invoked to explain the spectroscopic and dynamical properties of early-type galaxies (ETGs). However, no observations have yet been able to disentangle the physical driver. We analyze here a sample of 24 ETGs drawn from the CALIFA survey, deriving in a homogeneous way their stellar population and kinematic properties. We find that the local IMF is tightly related to the local metallicity, becoming more bottom-heavy toward metal-rich populations. Our result, combined with the galaxy mass–metallicity relation, naturally explains previous claims of a galaxy mass–IMF relation, derived from non-IFU spectra. If we assume that—within the star formation environment of ETGs—metallicity is the main driver of IMF variations, a significant revision of the interpretation of galaxy evolution observables is necessary

Automatic Drusen Quantification and Risk Assessment of Age-related Macular Degeneration on Color Fundus Images

NARCIS (Netherlands)

Grinsven, M.J.J.P. van; Lechanteur, Y.T.E.; Ven, J.P.H. van de; Ginneken, B. van; Hoyng, C.B.; Theelen, T.; Sanchez, C.I.

2013-01-01

PURPOSE: To evaluate a machine learning algorithm that allows for computer aided diagnosis (CAD) of non-advanced age-related macular degeneration (AMD) by providing an accurate detection and quantification of drusen location, area and size. METHODS: Color fundus photographs of 407 eyes without AMD

Making Sense of Metal Allergy and Hypersensitivity to Metallic Implants in Relation to Hand Surgery.

Science.gov (United States)

Christensen, Thomas J; Samant, Shefali A; Shin, Alexander Y

2017-09-01

All metals implanted into a biological system undergo some degree of corrosion depending upon its composition. The electrochemical process of corrosion produces free metal ions, which may activate the host's immune system through a variety of mechanisms. Whereas dermal metal hypersensitivity is common, affecting 10% to 15% of the population, the immune reaction from implanted metals is much less common (allergy and hypersensitivity producing a multitude of patient symptoms. Superficial symptoms may be mild to severe forms of dermatitis, urticaria, pruritus, and vasculitis, whereas deep sequelae include metallosis-related pseudotumor, implant loosening, and joint stiffness. Currently, there are clinical tests to evaluate patients for metal hypersensitivity, but there is little agreement regarding the ideal timing and clinical situation prompting the work-up of a patient for a metal allergy or hypersensitivity. An understanding of the epidemiology, etiology, basic science, diagnostic testing, and treatment of patients with suspected metal allergy, as it pertains to the current literature, will aid orthopedic and plastic surgeons of all subspecialties in the management of patients requiring metallic implants. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Development of multi-color scintillator based X-ray image intensifier

International Nuclear Information System (INIS)

Nittoh, Koichi; Konagai, Chikara; Noji, Takashi

2004-01-01

A multi-color scintillator based high-sensitive, wide dynamic range and long-life X-ray image intensifier has been developed. An europium activated Y 2 O 2 S scintillator, emitting red, green and blue photons of different intensities, is utilized as the output fluorescent screen of the intensifier. By combining this image intensifier with a suitably tuned high sensitive color CCD camera, it is possible for a sensitivity of the red color component to become six times higher than that of the conventional image intensifier. Simultaneous emission of a moderate green color and a weak blue color covers different sensitivity regions. This widens the dynamic range, by nearly two orders of ten. With this image intensifier, it is possible to image simultaneously complex objects containing various different X-ray transmission from paper, water or plastic to heavy metals. This high sensitivity intensifier, operated at lower X-ray exposure, causes less degradation of scintillator materials and less colorization of output screen glass, and thus helps achieve a longer lifetime. This color scintillator based image intensifier is being introduced for X-ray inspection in various fields

The use of micro-XRD for the study of glaze color decorations

Energy Technology Data Exchange (ETDEWEB)

Pradell, T.; Molina, G. [Universitat Politecnica de Catalunya, Dpt. Fisica i Enginyeria Nuclear, Castelldefels (Spain); Molera, J.; Pla, J. [Universitat de Vic, GRTD, Escola Politecnica Superior, Vic (Spain); Labrador, A. [BM16-ESRF, LLS, BP 220, Grenoble Cedex (France); Lund University, MAX IV Laboratory, Lund (Sweden)

2013-04-15

The compounds responsible for the colors and decorations in glass and glazed ceramics include: coloring agents (transition-metal ions), pigments (micro- and nanoprecipitates of compounds that either do not dissolve or recrystallize in the glassy matrix) and opacifiers (microcrystalline compounds with high light scattering capability). Their composition, structure and range of stability are highly dependent not only on the composition but also on the procedures followed to obtain them. Chemical composition of the colorants and crystallites may be obtained by means of SEM-EDX and WDX. Synchrotron radiation micro-X-ray diffraction (SR-micro-XRD) has a small beam size adequate (10 to 50 microns footprint size) to obtain the structural information of crystalline compounds and high brilliance, optimal for determining the crystallites even when present in low amounts. In addition, in glass decorations the crystallites often appear forming thin layers (from 10 to 100 micrometers thick) and they show a depth-dependent composition and crystal structure. Their nature and distribution across the glass/glaze decorations gives direct information on the technology of production and stability and may be related to the color and appearance. A selection of glass and glaze coloring agents and decorations are studied by means of SR-micro-XRD and SEM-EDX including: manganese brown, antimony yellow, red copper lusters and cobalt blue. The selection includes Medieval (Islamic, and Hispano Moresque) and Renaissance tin-glazed ceramics from the 10th to the 17th century AD. (orig.)

Chromaticity and Glossiness of Gold, Silver, and Bronze Colors