Optical properties of implanted Xe color centers in diamond

Science.gov (United States)

Sandstrom, Russell; Ke, Li; Martin, Aiden; Wang, Ziyu; Kianinia, Mehran; Green, Ben; Gao, Wei-bo; Aharonovich, Igor

2018-03-01

Optical properties of color centers in diamond have been the subject of intense research due to their promising applications in quantum photonics. In this work we study the optical properties of Xe related color centers implanted into nitrogen rich (type IIA) and an ultrapure, electronic grade diamond. The Xe defect has two zero phonon lines at ∼794 nm and 811 nm, which can be effectively excited using both green and red excitation, however, its emission in the nitrogen rich diamond is brighter. Near resonant excitation is performed at cryogenic temperatures and luminescence is probed under strong magnetic field. Our results are important towards the understanding of the Xe related defect and other near infrared color centers in diamond.

Optical properties of color centers in calcium-stabilized gadolinium gallium garnets

International Nuclear Information System (INIS)

Pogatshnik, G.J.; Cain, L.S.; Chen, Y.; Evans, B.D.

1991-01-01

The addition of small amounts of calcium during the crystal growth of large-diameter, gadolinium gallium garnet (GGG) crystals creates color centers that absorb in the near-uv region of the spectrum. Ultraviolet and γ-ray irradiation of the crystals produced changes in the intensities of the uv color-center bands along with a broad absorption throughout the visible spectrum. The color center that gives rise to an absorption band at 350 nm serves as a photoionizable donor center so that uv excitation results in a visible coloration of the crystals. The effects of oxidation and reduction treatments on the strength of the color-center bands and on the radiation response of the material were examined. Photoluminescence bands were observed in both reduced GGG crystals as well as crystals that were irradiated with neutrons. Visible coloration is likely to occur during flashlamp pumping of laser rods that utilize large-diameter GGG crystals as the laser host. The changes in the optical properties of the material under uv excitation indicate that the addition of small amounts of calcium to assist in the growth of large-diameter crystals is likely to result in the degradation of laser performance

Radiation-Induced Color Centers in LiF for Dosimetry at High Absorbed Dose Rates

DEFF Research Database (Denmark)

McLaughlin, W. L.; Miller, Arne; Ellis, S. C.

1980-01-01

Color centers formed by irradiation of optically clear crystals of pure LiF may be analyzed spectrophotometrically for dosimetry in the absorbed dose range from 102 to 107 Gy. Routine monitoring of intense electron beams is an important application. Both 6LiF and 7LiF forms are commercially...... available, and when used with filters as albedo dosimeters in pairs, they provide discrimination of neutron and gamma-ray doses....

Near-surface layer radiation color centers in lithium fluoride nanocrystals: Luminescence and composition

Energy Technology Data Exchange (ETDEWEB)

Voitovich, A.P., E-mail: voitovich@imaph.bas-net.by; Kalinov, V.S.; Stupak, A.P.; Novikov, A.N.; Runets, L.P.

2015-01-15

Lithium fluoride nanocrystals are irradiated by gamma quanta at 77 K. The radiation color centers formed in a near-surface layer of nanocrystals are studied. Absorption, luminescence and luminescence excitation spectra of the surface defects have been measured. It has been found that the luminescence excitation spectra for aggregated surface centers consist of two or three bands with not very much different intensities. Reactions of the surface centers separately with electrons and with anion vacancies have been investigated. Numbers of anion vacancies and electrons entering into the centers composition have been established and it has been found that F{sub S1}, F{sub S1}{sup −}, F{sub S2}, F{sub S2}{sup −}, F{sub S3}{sup +} and F{sub S3} types of the surface centers are formed. The degree of luminescence polarization has been defined and it has been determined that the polarization degree for F{sub S2}{sup +} centers changes sign under transition from one excitation band to another. It has been shown that during irradiation at 77 K radiation-induced defects are formed more efficiently on the surface than in the bulk. - Highlights: • Radiative color centers were fabricated in lithium fluoride nanocrystals. • The unique absorption and luminescence characteristics are inherent in the centers. • The reactions of these centers with electrons and anion vacancies were studied. • The degree of luminescence polarization was defined. • Numbers of anion vacancies and electrons forming the centers were established.

Color centers in KCN: a structural analysis of crystalline domains

International Nuclear Information System (INIS)

Carmo, L.C.S. do.

1976-03-01

Pure singlecrystals of KCN exposed to X-rays showed several color centers detected by EPR. The F center was identified through the correlation of its optical absorption band which satisfies the Ivey law for the KCN lattice parameter and the EPR spectrum typical of a center in an anionic site. Two other color centers were identified: N - 2 and HCN - . Two centers assigned to hydrogen atoms have their models proposed: U 2 and U 3 centers. Two other centers remain unidentified: an anionic and an extrinsic centers. The orthorhombic character of the N - 2 center EPR parameters allowed an structural analysis of the crystal line domains in the orthorhombic phase. The optical absorption spectrum of the HCN - center in KCl matrix was investigated and showed a set of resolved bands with a constant energy splitting; this splitting was associated to a vibrational mode of the excited state of this molecular ion. (author) [pt

Color centers of a borosilicate glass induced by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray

Science.gov (United States)

Du, Jishi; Wu, Jiehua; Zhao, Lili; Song, Lixin

2013-05-01

Optical absorption spectra, electron paramagnetic resonance (EPR) spectra, Raman spectra of a borosilicate glass after irradiation by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray were studied. The process of irradiation inducing color centers in the glass was discussed. The band gap of the glass before and after 60Co-γ ray irradiation was studied using Mott and Davis's theory, and it was found that calculated change of the band gap introduced a paradox, because Mott and Davis's theory on the band gap cannot be adopted in the study on the irradiated glass.

Color centers in KCN: ferro-elastic alignment and free optical absorption of phonons

International Nuclear Information System (INIS)

Grillo, M.L.N.

1983-01-01

Some color centers in KCN pure and KCL or KOH doped are studied. The used tecniques for detection of these color centers were optical absorption and electron paramagnetic resonance (EPR). To obtain this color centers crystals were always exposed to X-rays. With an optical absorption technique, one color center was analysed after X-ray irradiation followed by a suitable photochemical process. Throught the EPR technique the F center and three other centers produced by radiation damage were observed through several KCN solid phases. As in the orthorhombic and ferroelastic phase (temperatures between 168K and 83K), the crystals of KCN present one multidomain structure responsable for strong light scattering on the optical absorption spectra and EPR spectra that does not present the resolved lines formed above 168K, one system of aligned domains was obtained through mechanical stress built specifically to be capable of reducing the number of distinct domain, and this allowed us to observe of partially resolved EPR lines. (Auhtor) [pt

Studies on color-center formation in glass utilizing measurements made during 1 to 3 MeV electron irradiation

International Nuclear Information System (INIS)

Swyler, K.J.; Levy, P.W.

1976-01-01

The coloring of NBS 710 glass has been studied using a new facility for making optical absorption measurements during and after electron irradiation. The induced absorption contains three Gaussian shaped bands. The color center growth curves contain two saturating exponential and one linear components. After irradiation the coloring decays and can be described by three decreasing exponentials. At room temperature both the coloring curve plateau and coloring rate increase with increasing dose rate. Coloring measurements made at a fixed dose rate but at increasing temperature indicate: (1) the coloring curve plateau decreases with increasing temperature and coloring has not been observed at 400 0 C; (2) the plateau is reached more rapidly as the temperature increases; (3) the decay occurring after irradiation cannot be described by Arrhenius kinetics. At each temperature the coloring can be explained by simple kinetics. The temperature dependence of the decay can be explained if it is assumed that the thermal untrapping is controlled by a distribution of activation energies

Formation of H a - hydrogen centers upon additive coloration of alkaline-earth fluoride crystals

Science.gov (United States)

Radzhabov, E. A.; Egranov, A. V.; Shendrik, R. Yu.

2017-06-01

The mechanism of coloration of alkaline-earth fluoride crystals CaF2, SrF2, and BaF2 in calcium vapors in an autoclave with a cold zone is studied. It was found that the pressure in the autoclave upon constant evacuation by a vacuum pump within the temperature range of 500-800°C increases due to evaporation of metal calcium. In addition to the optical-absorption bands of color centers in the additively colored undoped crystals or to the bands of divalent ions in the crystals doped with rare-earth Sm, Yb, and Tm elements, there appear intense bands in the vacuum ultraviolet region at 7.7, 7.0, and 6.025 eV in CaF2, SrF2, and BaF2, respectively. These bands belong to the Ha - hydrogen centers. The formation of hydrogen centers is also confirmed by the appearance of the EPR signal of interstitial hydrogen atoms after X-ray irradiation of the additively colored crystals. Grinding of the outer edges of the colored crystals leads to a decrease in the hydrogen absorption-band intensity with depth to complete disappearance. The rate of hydrogen penetration inside the crystal is lower than the corresponding rate of color centers (anion vacancies) by a factor of tens. The visible color density of the outer regions of the hydrogen-containing crystals is several times lower than that of the inner region due to the competition between the color centers and hydrogen centers.

Optical determination and magnetic manipulation of a single nitrogen-vacancy color center in diamond nanocrystal

International Nuclear Information System (INIS)

Diep Lai, Ngoc; Zheng, Dingwei; Treussart, François; Roch, Jean-François

2010-01-01

The controlled and coherent manipulation of individual quantum systems is fundamental for the development of quantum information processing. The nitrogen-vacancy (NV) color center in diamond is a promising system since its photoluminescence is perfectly stable at room temperature and its electron spin can be optically read out at the individual level. We review here the experiments currently realized in our laboratory concerning the use of a single NV color center as the single photon source and the coherent magnetic manipulation of the electron spin associated with a single NV color center. Furthermore, we demonstrate a nanoscopy experiment based on the saturation absorption effect, which allows to optically pin-point a single NV color center at sub-λ resolution. This offers the possibility to independently address two or multiple magnetically coupled single NV color centers, which is a necessary step towards the realization of a diamond-based quantum computer

Efficiency of Cathodoluminescence Emission by Nitrogen-Vacancy Color Centers in Nanodiamonds.

Science.gov (United States)

Zhang, Huiliang; Glenn, David R; Schalek, Richard; Lichtman, Jeff W; Walsworth, Ronald L

2017-06-01

Correlated electron microscopy and cathodoluminescence (CL) imaging using functionalized nanoparticles is a promising nanoscale probe of biological structure and function. Nanodiamonds (NDs) that contain CL-emitting color centers are particularly well suited for such applications. The intensity of CL emission from NDs is determined by a combination of factors, including particle size, density of color centers, efficiency of energy deposition by electrons passing through the particle, and conversion efficiency from deposited energy to CL emission. This paper reports experiments and numerical simulations that investigate the relative importance of each of these factors in determining CL emission intensity from NDs containing nitrogen-vacancy (NV) color centers. In particular, it is found that CL can be detected from NV-doped NDs with dimensions as small as ≈40 nm, although CL emission decreases significantly for smaller NDs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photoluminescence of radiation-induced color centers in lithium fluoride thin films for advanced diagnostics of proton beams

Science.gov (United States)

Piccinini, M.; Ambrosini, F.; Ampollini, A.; Picardi, L.; Ronsivalle, C.; Bonfigli, F.; Libera, S.; Nichelatti, E.; Vincenti, M. A.; Montereali, R. M.

2015-06-01

Systematic irradiation of thermally evaporated 0.8 μm thick polycrystalline lithium fluoride films on glass was performed by proton beams of 3 and 7 MeV energies, produced by a linear accelerator, in a fluence range from 1011 to 1015 protons/cm2. The visible photoluminescence spectra of radiation-induced F2 and F3+ laser active color centers, which possess almost overlapping absorption bands at about 450 nm, were measured under laser pumping at 458 nm. On the basis of simulations of the linear energy transfer with proton penetration depth in LiF, it was possible to obtain the behavior of the measured integrated photoluminescence intensity of proton irradiated LiF films as a function of the deposited dose. The photoluminescence signal is linearly dependent on the deposited dose in the interval from 103 to about 106 Gy, independently from the used proton energies. This behavior is very encouraging for the development of advanced solid state radiation detectors based on optically transparent LiF thin films for proton beam diagnostics and two-dimensional dose mapping.

Silicon-Vacancy Color Centers in Nanodiamonds: Cathodoluminescence Imaging Marker in the Near Infrared

OpenAIRE

Zhang, Huiliang; Aharonovich, Igor; Glenn, David R.; Schalek, R.; Magyar, Andrew P.; Lichtman, Jeff W.; Hu, Evelyn L.; Walsworth, Ronald L.

2013-01-01

We demonstrate that nanodiamonds fabricated to incorporate silicon-vacancy (Si-V) color centers provide bright, spectrally narrow, and stable cathodoluminescence (CL) in the near-infrared. Si-V color centers containing nanodiamonds are promising as non-bleaching optical markers for correlated CL and secondary electron microscopy, including applications to nanoscale bioimaging.

The double luminescence of Color Centers

International Nuclear Information System (INIS)

Baldacchini, Giuseppe

2015-01-01

An experiment on the luminescence of Color Centers (CCs) carried out in 1987 at the ENEA Laboratories in Frascati had a negative result, but subsequent investigations showed that it was not a failure but rather a discovery of a new phenomenon. Since the coming of lasers, CCs in alkali halides have been successfully used as optically active materials, in particular FA Centers. One of these centers, well known for its medium infrared laser emission at 77 K, cooled further to 2 K emitted in the near infrared and without laser effect. Further investigations showed that the double luminescence was a fundamental property unknown until that time. This important discovery was achieved in Frascati because of the existence since 1973 of a solid and extensive expertise in the field of CCs, which continued over time and later on applied to the modern miniaturized photonic devices [it

Light induces petal color change in Quisqualis indica (Combretaceae

Directory of Open Access Journals (Sweden)

Juan Yan

2018-02-01

Full Text Available Petal color change, a common phenomenon in angiosperms, is induced by various environmental and endogenous factors. Interestingly, this phenomenon is important for attracting pollinators and further reproductive success. Quisqualis indica L. (Combretaceae is a tropical Asian climber that undergoes sequential petal color change from white to pink to red. This color changing process is thought to be a good strategy to attract more pollinators. However, the underlying physiological and biochemical mechanisms driving this petal color change phenomenon is still underexplored. In this context, we investigated whether changes in pH, pollination, light, temperature or ethylene mediate petal color change. We found that the detected changes in petal pH were not significant enough to induce color alterations. Additionally, pollination and temperatures of 20–30 °C did not alter the rate of petal color change; however, flowers did not open when exposed to constant temperatures at 15 °C or 35 °C. Moreover, the application of ethylene inhibitor, i.e., silver thiosulphate, did not prevent color change. It is worth mentioning here that in our study we found light as a strong factor influencing the whole process of petal color change, as petals remained white under dark conditions. Altogether, the present study suggests that petal color change in Q. indica is induced by light and not by changes in petal pH, pollination, ethylene, or temperature, while extremely low or high temperatures affect flower anthesis. In summary, our findings represent the probable mechanism underlying the phenomenon of petal color change, which is important for understanding flower color evolution.

Bragg superlattice for obtaining individual photoluminescence of diamond color centers in dense 3D ensembles

Science.gov (United States)

Kukushkin, V. A.

2017-10-01

A way to significantly increase the spatial resolution of the color center photoluminescence collection in chemically vapor-deposited (CVD) diamond at a fixed exciting beam focal volume is suggested. It is based on the creation of a narrow waveguide for the color center photoluminescence with a small number of allowed vertical indices of guided modes. The waveguide is formed between the top surface of a CVD diamond film and an underlaid mirror—a Bragg superlattice made of interchanging high- and low boron-doped layers of CVD diamond. The guided color center photoluminescence is extracted through the top surface of a CVD diamond film with the frustrated total internal reflection method. According to the results of simulation made for a case when color centers are nitrogen-vacancy (NV) centers, the suggested way allows to increase the maximal value of the NV center concentration still compatible with selective collection of their photoluminescence by several times at a fixed exciting beam focal volume. This increase is provided without the deterioration of the NV center photoluminescence collection efficiency.

Can grapheme-color synesthesia be induced by hypnosis?

Science.gov (United States)

Anderson, Hazel P.; Seth, Anil K.; Dienes, Zoltan; Ward, Jamie

2014-01-01

Grapheme-color synesthesia is a perceptual experience where graphemes, letters or words evoke a specific color, which are experienced either as spatially coincident with the grapheme inducer (projector sub-type) or elsewhere, perhaps without a definite spatial location (associator sub-type). Here, we address the question of whether synesthesia can be rapidly produced using a hypnotic color suggestion to examine the possibility of “hypnotic synesthesia”, i.e., subjectively experienced color hallucinations similar to those experienced by projector synesthetes. We assess the efficacy of this intervention using an “embedded figures” test, in which participants are required to detect a shape (e.g., a square) composed of local graphemic elements. For grapheme-color synesthetes, better performance on the task has been linked to a higher proportion of graphemes perceived as colored. We found no performance benefits on this test when using a hypnotic suggestion, as compared to a no-suggestion control condition. The same result was found when participants were separated according to the degree to which they were susceptible to the suggestion (number of colored trials perceived). However, we found a relationship between accuracy and subjective reports of color in those participants who reported a large proportion of colored trials: trials in which the embedded figure was accurately recognized (relative to trials in which it was not) were associated with reports of more intense colors occupying a greater spatial extent. Collectively, this implies that hypnotic color was only perceived after shape detection rather than aiding in shape detection via color-based perceptual grouping. The results suggest that hypnotically induced colors are not directly comparable to synesthetic ones. PMID:24829555

Process of optical excitation and relaxation of color center in synthetic diamond and its application to optoelectronics

International Nuclear Information System (INIS)

Nishida, Yoshio

1989-01-01

Irradiation of high-pressure synthesized diamond is carried out by using a nuclear reactor or a linac. Then, the effect of annealing on the color centers is observed. A study is made to identify different color centers and to provide techniques to control their introduction. Investigations cover the relation of color center formation with annealing temperature, dependence of color center formation on radiation dose, migration of H3 center and hydrogen, and applicability of five different color centers to optoelectronics. Next, a study is made of the formation and relaxation of the nitrogen vacancy (NV) center in a metastable excited state produced by optical excitation. An optical gain is essential to provide laser. Optical amplification is measured at the vibronic emission band of the NV center. An increase in absorption is detected, indicating that the NV center will not provide laser. In the optical excitation-relaxation process, the relaxation proceeds via a metastable state. Finally, hole burning of ZPL of the NV center is observed in the temperature range from 20K to 80K, and some of its features are described. (N.K.)

Photoluminescence of radiation-induced color centers in lithium fluoride thin films for advanced diagnostics of proton beams

Energy Technology Data Exchange (ETDEWEB)

Piccinini, M., E-mail: massimo.piccinini@enea.it; Ampollini, A.; Picardi, L.; Ronsivalle, C.; Bonfigli, F.; Libera, S.; Vincenti, M. A.; Montereali, R. M. [ENEA, C.R. Frascati, UTAPRAD, Technical Unit for Development and Applications of Radiations, Via E. Fermi 45, 00044 Frascati (Rome) (Italy); Ambrosini, F. [University Sapienza-Roma I, Piazzale Aldo Moro 5, 00185 Rome (Italy); Nichelatti, E. [ENEA, C.R. Casaccia, UTTMAT, Technical Unit for Materials Technologies, Via Anguillarese 301, 00123 S. Maria di Galeria (Rome) (Italy)

2015-06-29

Systematic irradiation of thermally evaporated 0.8 μm thick polycrystalline lithium fluoride films on glass was performed by proton beams of 3 and 7 MeV energies, produced by a linear accelerator, in a fluence range from 10{sup 11} to 10{sup 15} protons/cm{sup 2}. The visible photoluminescence spectra of radiation-induced F{sub 2} and F{sub 3}{sup +} laser active color centers, which possess almost overlapping absorption bands at about 450 nm, were measured under laser pumping at 458 nm. On the basis of simulations of the linear energy transfer with proton penetration depth in LiF, it was possible to obtain the behavior of the measured integrated photoluminescence intensity of proton irradiated LiF films as a function of the deposited dose. The photoluminescence signal is linearly dependent on the deposited dose in the interval from 10{sup 3} to about 10{sup 6 }Gy, independently from the used proton energies. This behavior is very encouraging for the development of advanced solid state radiation detectors based on optically transparent LiF thin films for proton beam diagnostics and two-dimensional dose mapping.

Enhancing the brightness of electrically driven single-photon sources using color centers in silicon carbide

Science.gov (United States)

Khramtsov, Igor A.; Vyshnevyy, Andrey A.; Fedyanin, Dmitry Yu.

2018-03-01

Practical applications of quantum information technologies exploiting the quantum nature of light require efficient and bright true single-photon sources which operate under ambient conditions. Currently, point defects in the crystal lattice of diamond known as color centers have taken the lead in the race for the most promising quantum system for practical non-classical light sources. This work is focused on a different quantum optoelectronic material, namely a color center in silicon carbide, and reveals the physics behind the process of single-photon emission from color centers in SiC under electrical pumping. We show that color centers in silicon carbide can be far superior to any other quantum light emitter under electrical control at room temperature. Using a comprehensive theoretical approach and rigorous numerical simulations, we demonstrate that at room temperature, the photon emission rate from a p-i-n silicon carbide single-photon emitting diode can exceed 5 Gcounts/s, which is higher than what can be achieved with electrically driven color centers in diamond or epitaxial quantum dots. These findings lay the foundation for the development of practical photonic quantum devices which can be produced in a well-developed CMOS compatible process flow.

Radiation induced color center and colloid formation in synthetic NaCl and natural rock salt

International Nuclear Information System (INIS)

Levy, P.W.; Swyler, K.J.; Klaffky, R.W.

1979-01-01

F-center and colloid particle formation has been studied in synthetic NaCl and natural rock salt crystals with apparatus for making optical absorption measurements during irradiation. F-center and colloid formation are functions of temperature, dose, dose rate, strain applied prior to irradiation and numerous other factors. Many of the observed properties are in accord with the Jain-Lidiard theory for radiation induced F-center and colloid growth above room temperature

Graphemes Sharing Phonetic Features Tend to Induce Similar Synesthetic Colors.

Science.gov (United States)

Kang, Mi-Jeong; Kim, Yeseul; Shin, Ji-Young; Kim, Chai-Youn

2017-01-01

Individuals with grapheme-color synesthesia experience idiosyncratic colors when viewing achromatic letters or digits. Despite large individual differences in grapheme-color association, synesthetes tend to associate graphemes sharing a perceptual feature with similar synesthetic colors. Sound has been suggested as one such feature. In the present study, we investigated whether graphemes of which representative phonemes have similar phonetic features tend to be associated with analogous synesthetic colors. We tested five Korean multilingual synesthetes on a color-matching task using graphemes from Korean, English, and Japanese orthography. We then compared the similarity of synesthetic colors induced by those characters sharing a phonetic feature. Results showed that graphemes associated with the same phonetic feature tend to induce synesthetic color in both within- and cross-script analyses. Moreover, this tendency was consistent for graphemes that are not transliterable into each other as well as graphemes that are. These results suggest that it is the perceptual-i.e., phonetic-properties associated with graphemes, not just conceptual associations such as transliteration, that determine synesthetic color.

Graphemes Sharing Phonetic Features Tend to Induce Similar Synesthetic Colors

Science.gov (United States)

Kang, Mi-Jeong; Kim, Yeseul; Shin, Ji-Young; Kim, Chai-Youn

2017-01-01

Individuals with grapheme-color synesthesia experience idiosyncratic colors when viewing achromatic letters or digits. Despite large individual differences in grapheme-color association, synesthetes tend to associate graphemes sharing a perceptual feature with similar synesthetic colors. Sound has been suggested as one such feature. In the present study, we investigated whether graphemes of which representative phonemes have similar phonetic features tend to be associated with analogous synesthetic colors. We tested five Korean multilingual synesthetes on a color-matching task using graphemes from Korean, English, and Japanese orthography. We then compared the similarity of synesthetic colors induced by those characters sharing a phonetic feature. Results showed that graphemes associated with the same phonetic feature tend to induce synesthetic color in both within- and cross-script analyses. Moreover, this tendency was consistent for graphemes that are not transliterable into each other as well as graphemes that are. These results suggest that it is the perceptual—i.e., phonetic—properties associated with graphemes, not just conceptual associations such as transliteration, that determine synesthetic color. PMID:28348537

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...

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.

Evaluation of induced color changes in chicken breast meat during simulation of pink color defect.

Science.gov (United States)

Holownia, K; Chinnan, M S; Reynolds, A E; Koehler, P E

2003-06-01

The objective of the study was to establish a pink threshold and simulate the pink defect in cooked chicken breast meat with treatment combinations that would induce significant changes in the color of raw and cooked meat. The subjective pink threshold used in judging pink discoloration was established at a* = 3.8. Samples of three color groups (normal, lighter than normal, and darker than normal) of boneless, skinless chicken breast muscles were selected based on instrumental color values. The in situ changes were induced using sodium chloride, sodium tripolyphosphate, sodium erythorbate, and sodium nitrite at two levels: present and not present. Fillets in all treatments were subjected to individual injections, followed by tumbling, cooking, and chilling. Samples were analyzed for color [lightness (L*), red/green axis (a*), yellow/blue axis (b*)] and reflectance spectra. Simulation of the pink defect was achieved in eight of the 16 treatment combinations when sodium nitrite was present and in an additional two treatment combinations when it was absent. Pinking in cooked samples was affected (P meat color. Results confirmed that it was possible to simulate the undesired pinking in cooked chicken white meat when in situ conditions were induced by sodium chloride, sodium tripolyphosphate, and sodium nitrite. The continuation of the simulation study can aid in developing alternative processing methods to eliminate potential pink defects.

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

OpenAIRE

Sørensen, Thomas Alrik; Ásgeirsson, Árni Gunnar

2015-01-01

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 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 ...

Photoluminescence of magnesium-associated color centers in LiF crystals implanted with magnesium ions

Science.gov (United States)

Nebogin, S. A.; Ivanov, N. A.; Bryukvina, L. I.; V. Shipitsin, N.; E. Rzhechitskii, A.; Papernyi, V. L.

2018-05-01

In the present paper, the effect of magnesium nanoparticles implanted in a LiF crystal on the optical properties of color centers is studied. The transmittance spectra and AFM images demonstrate effective formation of the color centers and magnesium nanoparticles in an implanted layer of ∼ 60-100 nm in thickness. Under thermal annealing, a periodical structure is formed on the surface of the crystal and in the implanted layer due to self-organization of the magnesium nanoparticles. Upon excitation by argon laser with a wavelength of 488 nm at 5 K, in a LiF crystal, implanted with magnesium ions as well as in heavily γ-irradiated LiF: Mg crystals, luminescence of the color centers at λmax = 640 nm with a zero-phonon line at 601.5 nm is observed. The interaction of magnesium nanoparticles and luminescing color centers in a layer implanted with magnesium ions has been revealed. It is shown that the luminescence intensity of the implanted layer at a wavelength of 640 nm is by more than two thousand times higher than that of a heavily γ-irradiated LiF: Mg crystal. The broadening of the zero-phonon line at 601.5 nm in the spectrum of the implanted layer indicates the interaction of the emitting quantum system with local field of the surface plasmons of magnesium nanoparticles. The focus of this work is to further optimize the processing parameters in a way to result in luminescence great enhancement of color centers by magnesium nanoparticles in LiF.

Three-coloring graphs with no induced seven-vertex path II : using a triangle

OpenAIRE

Chudnovsky, Maria; Maceli, Peter; Zhong, Mingxian

2015-01-01

In this paper, we give a polynomial time algorithm which determines if a given graph containing a triangle and no induced seven-vertex path is 3-colorable, and gives an explicit coloring if one exists. In previous work, we gave a polynomial time algorithm for three-coloring triangle-free graphs with no induced seven-vertex path. Combined, our work shows that three-coloring a graph with no induced seven-vertex path can be done in polynomial time.

Distal-less induces elemental color patterns in Junonia butterfly wings.

Science.gov (United States)

Dhungel, Bidur; Ohno, Yoshikazu; Matayoshi, Rie; Iwasaki, Mayo; Taira, Wataru; Adhikari, Kiran; Gurung, Raj; Otaki, Joji M

2016-01-01

The border ocellus, or eyespot, is a conspicuous color pattern element in butterfly wings. For two decades, it has been hypothesized that transcription factors such as Distal-less (Dll) are responsible for eyespot pattern development in butterfly wings, based on their expression in the prospective eyespots. In particular, it has been suggested that Dll is a determinant for eyespot size. However, functional evidence for this hypothesis has remained incomplete, due to technical difficulties. Here, we show that ectopically expressed Dll induces ectopic elemental color patterns in the adult wings of the blue pansy butterfly, Junonia orithya (Lepidoptera, Nymphalidae). Using baculovirus-mediated gene transfer, we misexpressed Dll protein fused with green fluorescent protein (GFP) in pupal wings, resulting in ectopic color patterns, but not the formation of intact eyespots. Induced changes included clusters of black and orange scales (a basic feature of eyespot patterns), black and gray scales, and inhibition of cover scale development. In contrast, ectopic expression of GFP alone did not induce any color pattern changes using the same baculovirus-mediated gene transfer system. These results suggest that Dll plays an instructive role in the development of color pattern elements in butterfly wings, although Dll alone may not be sufficient to induce a complete eyespot. This study thus experimentally supports the hypothesis of Dll function in eyespot development.

Influence of chromium ions on the color center formation in crystals with garnet structure

International Nuclear Information System (INIS)

Ashurov, M.Kh.; Zharikov, E.V.; Laptev, V.V.

1985-01-01

The in fluence of chromium ions on the color center formation in crystals of yttrium-aluminium garnet, gadolinium-gallium garnet, gadolinium-scandium-gallium garnet, and yttrium-scandium-gallium garnet is studied. In addition to basic activator ions these crystals were coactivated also by chromium ions with two wide bands of fundamental absorption within the range of pump tube radiation with maximas close to 450 and 650 nm. The color centers for γ-irradiated samples were observed at 300 K by measuring the adsorption spectra within the 300-800 nm range. Temperature of destruction of the charge trapping sites was determined by the method of thermoluminescence measuring in the 100-500 K temperature range. Detection of recombination center luminescence was accomplished within the 200-1600 nm wavelength range. Chromium ions are found to hinder the formation of color centers as a result of γ-irradiation at room and higher temperatures within the wavelength range over 300 nm; i.e. Cr 3+ ions increase radiation resistance of all the investigated crystals

Color and texture associations in voice-induced synesthesia

Science.gov (United States)

Moos, Anja; Simmons, David; Simner, Julia; Smith, Rachel

2013-01-01

Voice-induced synesthesia, a form of synesthesia in which synesthetic perceptions are induced by the sounds of people's voices, appears to be relatively rare and has not been systematically studied. In this study we investigated the synesthetic color and visual texture perceptions experienced in response to different types of “voice quality” (e.g., nasal, whisper, falsetto). Experiences of three different groups—self-reported voice synesthetes, phoneticians, and controls—were compared using both qualitative and quantitative analysis in a study conducted online. Whilst, in the qualitative analysis, synesthetes used more color and texture terms to describe voices than either phoneticians or controls, only weak differences, and many similarities, between groups were found in the quantitative analysis. Notable consistent results between groups were the matching of higher speech fundamental frequencies with lighter and redder colors, the matching of “whispery” voices with smoke-like textures, and the matching of “harsh” and “creaky” voices with textures resembling dry cracked soil. These data are discussed in the light of current thinking about definitions and categorizations of synesthesia, especially in cases where individuals apparently have a range of different synesthetic inducers. PMID:24032023

Si-related color centers in nanocrystalline diamond thin films

Czech Academy of Sciences Publication Activity Database

Potocký, Štěpán; Holovský, Jakub; Remeš, Zdeněk; Müller, Martin; Kočka, Jan; Kromka, Alexander

2014-01-01

Roč. 251, č. 12 (2014), s. 2603-2606 ISSN 0370-1972 R&D Projects: GA TA ČR TA01011740; GA ČR(CZ) GA14-04790S; GA MŠk LH12186 Institutional support: RVO:68378271 Keywords : chemical vapor deposition * color center * diamond * photoluminescence * plasma Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.489, year: 2014

Fractal kinetics of radiation-induced point-defect formation and decay in amorphous insulators: Application to color centers in silica-based optical fibers

Science.gov (United States)

Griscom, David L.

2001-11-01

Formalisms have been developed to express the time evolution of bimolecular processes taking place in fractal spaces. These ``stretched-second-order'' solutions are specifically applicable to radiation-induced electron-hole pairs and/or vacancy-interstitial pairs in insulating glasses. Like the analogous Kohlrausch-type (stretched-first-order) expressions, the present solutions are functions of (kt)β, where 0the new second-order formalism and the familiar Kohlrausch approach have been used to fit experimental data (induced optical absorptions in silica-based glasses monitored at selected wavelengths) that serve as proxies for the numbers of color centers created by γ irradiation and/or destroyed by processes involving thermal, optical, or γ-ray activation. Two material systems were investigated: (1) optical fibers with Ge-doped-silica cores and (2) fibers with low-OH/low-chloride pure-silica cores. Successful fits of the growth curves for the Ge-doped-silica-core fibers at four widely separated dose rates were accomplished using solutions for color-center concentrations, N[(kt)β], which approach steady-state values, Nsat, as t-->∞. The parametrization of these fits reveals some unexpected, and potentially useful, empirical rules regarding the dose-rate dependences of β, k, and Nsat in the fractal regime (0the pure-silica-core fibers as well. In both material systems, there appear to be fractal classical phase transitions at certain threshold values of dose rate, below which the dose-rate dependencies of k and Nsat revert to those specified by classical (β=1) first- or second-order kinetics. For ktthe first- and second-order fractal kinetic growth curves become identical, i.e., N((kt)β)~Atβ, where the coefficient A depends on dose rate but not kinetic order. It is found empirically that A depends on the 3β/2 power of dose rate in both first- and second-order kinetics, thus ``accidentally'' becoming linearly proportional to dose rate in cases where β~2

Luminescence of color centers in MgF2 crystals

International Nuclear Information System (INIS)

Vakhidov, Sh.A.; Nuritdinov, I.; Musaeva, M.A.

1999-01-01

The photoluminescence characteristics of the proper radiation color centers of the MgF 2 crystals are studied. The samples were irradiated by the 60 Co source γ-rays up to the dose 10 7 Gy. The bands with the maxima in the area of 420, 460, 550 and 620 nm were identified, which are excited correspondingly in the bands with the maxima of 370, 320, 410 and 480 nm

Elastic atomic displacements and color center creation in LiF crystals irradiated with 3-, 9- and 12-MeV Au ions

International Nuclear Information System (INIS)

Sorokin, M.V.; Papaleo, R.M.; Schwartz, K.

2009-01-01

Creation of color centers in LiF under irradiation with 3-12-MeV Au ions was studied. Comparison of experimental data of color center creation with computer simulation of the energy deposition and elastic atomic displacements reveals the role of elastic collisions in defect creation by these ions, which have comparable magnitudes of electronic and elastic stopping. The experimentally measured efficiency of color center creation and that predicted by the simulation of elastic displacements have a similar dependence on the projectile energy. Thus, the color center creation is mainly associated with the elastic collisions, despite the relatively large values of the electronic stopping power for these ions. (orig.)

Hot colors: the nature and specificity of color-induced nasal thermal sensations.

Science.gov (United States)

Michael, George A; Galich, Hélène; Relland, Solveig; Prud'hon, Sabine

2010-03-05

The nature of the recently discovered color-induced nasal thermal sensations was investigated in four Experiments. Subjects were required to fixate a bottle containing a red or green solution presented centrally (Exp1 and Exp4) or laterally (Exp2) and to sniff another bottle, always the same one, but which they were not allowed to see, containing 10 ml of a colorless, odorless and trigeminal-free solution. Each nostril was tested separately, and subjects were asked whether the sniffed solution induced warming or cooling sensations (plus an ambient sensation in Exp4) in the nasal cavity. The results of Experiments 1 and 2 confirmed the warming/left nostril-cooling/right nostril dissociation, suggesting the existence of different lateralized processes for thermal processing. However, Experiment 2 failed to demonstrate dominance of warming responses when subjects' eyes were directed to the left or cooling responses when they were directed to the right. Nor did gaze direction interact with the tested nostril. This suggests that the color-induced thermal sensations are specifically related to the nasal trigeminal system, rather than a general process related to general hemispheric activity. When the exposed bottles were colorless (Exp3), no lateralized patterns were observed, suggesting, in combination with the results of Experiments 1 and 2, that both color cues and nasal stimulations are necessary for lateralized patterns to arise. Rendering the temperature judgment even more difficult (Exp4), made the lateralized patterns shift towards the associated (i.e., ambient) responses. The results are discussed in a general framework which considers that, even in the absence of real thermal stimulus, preparing to process thermal stimuli in the nasal cavity may activate the underlying lateralized neural mechanisms, and that those mechanisms are reflected in the responses. Copyright 2009 Elsevier B.V. All rights reserved.

Color adaptation induced from linguistic description of color.

Directory of Open Access Journals (Sweden)

Liling Zheng

Full Text Available Recent theories propose that language comprehension can influence perception at the low level of perceptual system. Here, we used an adaptation paradigm to test whether processing language caused color adaptation in the visual system. After prolonged exposure to a color linguistic context, which depicted red, green, or non-specific color scenes, participants immediately performed a color detection task, indicating whether they saw a green color square in the middle of a white screen or not. We found that participants were more likely to perceive the green color square after listening to discourses denoting red compared to discourses denoting green or conveying non-specific color information, revealing that language comprehension caused an adaptation aftereffect at the perceptual level. Therefore, semantic representation of color may have a common neural substrate with color perception. These results are in line with the simulation view of embodied language comprehension theory, which predicts that processing language reactivates the sensorimotor systems that are engaged during real experience.

Food Color Induced Hepatotoxicity in Swiss Albino Rats, Rattus norvegicus.

Science.gov (United States)

Saxena, Beenam; Sharma, Shiv

2015-01-01

Certain dietary constituents can induce toxicity and play a critical role in the development of several hepatic disorders. Tartrazine, metanil yellow and sunset yellow are widely used azo dyes in food products, so the present study is aimed to investigate the food color induced hepatotoxicity in Swiss albino rats. Swiss albino rats were divided into four groups, each group having six animals. Group I served as control, Group II, Group III and Group IV were administered with 25, 50 and 75 mg/kg body weight blend of sunset yellow, metanil yellow and tartrazine for 30 days. Hepatotoxicity in rats treated with a blend of these food colors was studied by assessing parameters such as serum total protein, serum albumin, serum alkaline phosphatase (ALP) as well as hepatic malondialdehyde (MDA). The activity of superoxide dismutase (SOD), reduced glutathione (GSH) and catalase (CAT) were assessed. Significantly increased concentrations of serum total protein, serum albumin, serum ALP and hepatic MDA and significantly lowered levels of SOD, reduced GSH and CAT in the liver tissue of treated animals were observed when compared with control animals. The alteration in the liver includes necrosis of hepatocytes, infiltration and vacuolation. The result indicates that consumption of food color in diet induces liver tissue damage. The used doses of food color were mostly attributable to hepatocellular damage and drastic alteration in antioxidant defense system.

Primary and aggregate color centers in proton irradiated LiF crystals and thin films for luminescent solid state detectors

Science.gov (United States)

Piccinini, M.; Ambrosini, F.; Ampollini, A.; Bonfigli, F.; Libera, S.; Picardi, L.; Ronsivalle, C.; Vincenti, M. A.; Montereali, R. M.

2015-04-01

Proton beams of 3 MeV energy, produced by the injector of a linear accelerator for proton therapy, were used to irradiate at room temperature lithium fluoride crystals and polycrystalline thin films grown by thermal evaporation. The irradiation fluence range was 1011-1015 protons/cm2. The proton irradiation induced the stable formation of primary and aggregate color centers. Their formation was investigated by optical absorption and photoluminescence spectroscopy. The F2 and F3+ photoluminescence intensities, carefully measured in LiF crystals and thin films, show linear behaviours up to different maximum values of the irradiation fluence, after which a quenching is observed, depending on the nature of the samples (crystals and films). The Principal Component Analysis, applied to the absorption spectra of colored crystals, allowed to clearly identify the formation of more complex aggregate defects in samples irradiated at highest fluences.

Color Fundus Photography versus Fluorescein Angiography in Identification of the Macular Center and Zone in Retinopathy of Prematurity

Science.gov (United States)

Patel, Samir N.; Klufas, Michael A.; Ryan, Michael C.; Jonas, Karyn E.; Ostmo, Susan; Martinez-Castellanos, Maria Ana; Berrocal, Audina M.; Chiang, Michael F.; Chan, R.V. Paul

2016-01-01

Purpose To examine the utility of fluorescein angiography (FA) in identification of the macular center and the diagnosis of zone in patients with retinopathy of prematurity (ROP). Design Validity and reliability analysis of diagnostic tools Methods 32 sets (16 color fundus photographs; 16 color fundus photographs paired with the corresponding FA) of wide-angle retinal images obtained from 16 eyes of eight infants with ROP were compiled on a secure web site. 9 ROP experts (3 pediatric ophthalmologists; 6 vitreoretinal surgeons) participated in the study. For each image set, experts identified the macular center and provided a diagnosis of zone. Main Outcome Measures (1) Sensitivity and specificity of zone diagnosis (2) “Computer facilitated diagnosis of zone,” based on precise measurement of the macular center, optic disc center, and peripheral ROP. Results Computer facilitated diagnosis of zone agreed with the expert’s diagnosis of zone in 28/45 (62%) cases using color fundus photographs and in 31/45 (69%) cases using FA. Mean (95% CI) sensitivity for detection of zone I by experts as compared to a consensus reference standard diagnosis when interpreting the color fundus images alone versus interpreting the color fundus photographs and FA was 47% (35.3% – 59.3%) and 61.1% (48.9% – 72.4%), respectively, (t(9) ≥ (2.063), p = 0.073). Conclusions There is a marginally significant difference in zone diagnosis when using color fundus photographs compared to using color fundus photographs and the corresponding fluorescein angiograms. There is inconsistency between traditional zone diagnosis (based on ophthalmoscopic exam and image review) compared to a computer-facilitated diagnosis of zone. PMID:25637180

Food Color Induced Hepatotoxicity in Swiss Albino Rats, Rattus norvegicus

Science.gov (United States)

Saxena, Beenam; Sharma, Shiv

2015-01-01

Objective: Certain dietary constituents can induce toxicity and play a critical role in the development of several hepatic disorders. Tartrazine, metanil yellow and sunset yellow are widely used azo dyes in food products, so the present study is aimed to investigate the food color induced hepatotoxicity in Swiss albino rats. Materials and Methods: Swiss albino rats were divided into four groups, each group having six animals. Group I served as control, Group II, Group III and Group IV were administered with 25, 50 and 75 mg/kg body weight blend of sunset yellow, metanil yellow and tartrazine for 30 days. Hepatotoxicity in rats treated with a blend of these food colors was studied by assessing parameters such as serum total protein, serum albumin, serum alkaline phosphatase (ALP) as well as hepatic malondialdehyde (MDA). The activity of superoxide dismutase (SOD), reduced glutathione (GSH) and catalase (CAT) were assessed. Results: Significantly increased concentrations of serum total protein, serum albumin, serum ALP and hepatic MDA and significantly lowered levels of SOD, reduced GSH and CAT in the liver tissue of treated animals were observed when compared with control animals. The alteration in the liver includes necrosis of hepatocytes, infiltration and vacuolation. Conclusion: The result indicates that consumption of food color in diet induces liver tissue damage. The used doses of food color were mostly attributable to hepatocellular damage and drastic alteration in antioxidant defense system. PMID:26862277

Modification of Color Centers by Electron Bombardment: Final Report CRADA No. TC-0460-93-A

Energy Technology Data Exchange (ETDEWEB)

Van Bibber, Karl [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alger, Don M. [Quali-Tech, Inc., Columbia, MO (United States)

2000-11-30

The purpose of the project was to: Identify those electron beam irradiation parameters most relevant to process quality and efficiency, to producing and modifying color centers in topaz. Develop and test improved radiation processing techniques, and evaluate their potential applicability to other types of semi-precious gems. Develop an optimized data base for the process and procedures for identifying and characterizing material from new and diverse sources. Transfer new processing technology to the private sector, and, until they are implemented industrially, to perform radiation dosing to partially satisfy existing excess demand. We planned to define the interaction between sample purity level, the physics of irradiation to achieve color cent-er modification on a reproducible basis and demonstration of the resulting process on a commercially viable basis. The primary deliverable was the increased knowledge base in terms of expanded understanding of the systematics of color center modification in materials, and an extensive database of electron beam parameters which would optimize the efficiency and quality of radiation processing of topaz from diverse sources. The radiation processing of these stones constitutes a deliverable to Quali-Tech by LLNL.

Primary and aggregate color centers in proton irradiated LiF crystals and thin films for luminescent solid state detectors

International Nuclear Information System (INIS)

Piccinini, M; Ambrosini, F; Ampollini, A; Bonfigli, F; Libera, S; Picardi, L; Ronsivalle, C; Vincenti, M A; Montereali, R M

2015-01-01

Proton beams of 3 MeV energy, produced by the injector of a linear accelerator for proton therapy, were used to irradiate at room temperature lithium fluoride crystals and polycrystalline thin films grown by thermal evaporation. The irradiation fluence range was 10 11 -10 15 protons/cm 2 . The proton irradiation induced the stable formation of primary and aggregate color centers. Their formation was investigated by optical absorption and photoluminescence spectroscopy. The F 2 and F 3 + photoluminescence intensities, carefully measured in LiF crystals and thin films, show linear behaviours up to different maximum values of the irradiation fluence, after which a quenching is observed, depending on the nature of the samples (crystals and films). The Principal Component Analysis, applied to the absorption spectra of colored crystals, allowed to clearly identify the formation of more complex aggregate defects in samples irradiated at highest fluences. (paper)

Size-controlled fluorescent nanodiamonds: A facile method of fabrication and color-center counting

KAUST Repository

Mahfouz, Remi

2013-01-01

We present a facile method for the production of fluorescent diamond nanocrystals (DNCs) of different sizes and efficiently quantify the concentration of emitting defect color centers (DCCs) of each DNC size. We prepared the DNCs by ball-milling commercially available micrometer-sized synthetic (high pressure, high temperature (HPHT)) diamonds and then separated the as-produced DNCs by density gradient ultracentrifugation (DGU) into size-controlled fractions. A protocol to enhance the uniformity of the nitrogen-vacancy (NV) centers in the diamonds was devised by depositing the DNCs as a dense monolayer on amino-silanized silicon substrates and then subjecting the monolayer to He+ beam irradiation. Using a standard confocal setup, we analyzed the average number of NV centers per crystal, and obtained a quantitative relationship between the DNC particle size and the NV number per crystal. This relationship was in good agreement with results from previous studies that used more elaborate setups. Our findings suggest that nanocrystal size separation by DGU may be used to control the number of defects per nanocrystal. The efficient approaches described herein to control and quantify DCCs are valuable to researchers as they explore applications for color centers and new strategies to create them. © 2013 The Royal Society of Chemistry.

Color formation study of irradiated polymers by electron beam

International Nuclear Information System (INIS)

Nardi, Daniela Teves

2004-01-01

Color formation on national and commercial polymers (polymethyl methacrylate, polystyrene and polycarbonate) irradiated by electrons beam was investigated by colorimetry (CIELab), electron spectroscopy resonance (ESR), photoacoustic infrared spectroscopy (FTIR-PAS) and differential exploratory calorimetry (DSC). The heat effect on colorimetric properties was investigated after heating (110 deg C for 1 hour) of irradiated polymers at 150 kGy. The rule of oxygen in colorimetric properties of irradiated polycarbonate was investigated in the air presence and absence (p = 10 -3 mmHg). The visual aspect did not agree with colorimetric parameters only for polycarbonate. Yellow color and darkness were induced by radiation for all studied polymers varying only the intensity and behavior in function of post-irradiation time and heating. Polymethyl methacrylate and polystyrene ESR spectra showed that radicals could be responsible by yellow color centers. Wherever, in polycarbonate, color centers were not due radical species. The nature of color centers for any studied polymer was not study by FTIR-PAS because there were no changes in FTIR-PAS spectra neither in function of dose nor heating. Polycarbonate was the most radiosensible and polystyrene was the most radioresistant of all studied polymers in concern of colorimetric properties. (author)

Kinetics of heat-induced color change of a tuna-vegetable mixture

OpenAIRE

Scherer, Erika; Sandoval, Aleida J; Barreiro, José A

2009-01-01

Heat induced color change kinetics in a tuna-vegetable mixture was evaluated by measuring color parameter "L" (Hunter-Lab) and 5-hydroxi-methyl-furfural (5-HMF) accumulation. For this purpose small reusable stainless steel TDT cans were used and the kinetic studies performed in a temperature range characteristic of thermal processing of low acid canned foods (110-125°C). The color parameter L was better described by a pseudo zero order while a pseudo first order reaction was found for 5-HMF a...

Multiphoton-Excited Fluorescence of Silicon-Vacancy Color Centers in Diamond

Science.gov (United States)

Higbie, J. M.; Perreault, J. D.; Acosta, V. M.; Belthangady, C.; Lebel, P.; Kim, M. H.; Nguyen, K.; Demas, V.; Bajaj, V.; Santori, C.

2017-05-01

Silicon-vacancy color centers in nanodiamonds are promising as fluorescent labels for biological applications, with a narrow, nonbleaching emission line at 738 nm. Two-photon excitation of this fluorescence offers the possibility of low-background detection at significant tissue depth with high three-dimensional spatial resolution. We measure the two-photon fluorescence cross section of a negatively charged silicon vacancy (Si -V- ) in ion-implanted bulk diamond to be 0.74 (19 )×10-50 cm4 s /photon at an excitation wavelength of 1040 nm. Compared to the diamond nitrogen-vacancy center, the expected detection threshold of a two-photon excited Si -V center is more than an order of magnitude lower, largely due to its much narrower linewidth. We also present measurements of two- and three-photon excitation spectra, finding an increase in the two-photon cross section with decreasing wavelength, and we discuss the physical interpretation of the spectra in the context of existing models of the Si -V energy-level structure.

Contour adaptation reduces the spreading of edge induced colors.

Science.gov (United States)

Coia, Andrew J; Crognale, Michael A

2017-04-25

Brief exposure to flickering achromatic outlines of an area causes a reduction in the brightness contrast of the surface inside the area. This contour adaptation to achromatic contours does not reduce surface contrast when the surface is chromatic (the saturation or colorimetric purity of the surface is maintained). In addition to reducing the brightness of physical luminance contrast, contour adaptation also reduces (or even reverses) the illusory brightness contrast seen in the Craik-O'Brien-Cornsweet illusion, in which two physically identical grey areas appear different brightness because of a sharp luminance edge separating them. Chromatic color spreading illusions also occur with chromatic inducing edges, and an unanswered question is whether contour adaptation can reduce the perceived contrast of illusory color spreading from edges, even though it cannot reduce the perceived contrast of physical surface color. The current studies use a color spreading illusion known as the watercolor effect in order to test whether illusory color spreading is affected by contour adaptation. The general findings of physical achromatic contrast being reduced and chromatic contrast being robust to contour adaptation were replicated. However, both illusory brightness and color were reduced by contour adaptation, even when the illusion edges only differed in chromatic contrast with each other and the background. Additional studies adapting to chromatic contours showed opposite effects on illusory color contrast than achromatic adaptation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nitrogen-Vacancy color center in diamond-emerging nanoscale applications in bioimaging and biosensing.

Science.gov (United States)

Balasubramanian, Gopalakrishnan; Lazariev, Andrii; Arumugam, Sri Ranjini; Duan, De-Wen

2014-06-01

Nitrogen-Vacancy (NV) color center in diamond is a flourishing research area that, in recent years, has displayed remarkable progress. The system offers great potential for realizing futuristic applications in nanoscience, benefiting a range of fields from bioimaging to quantum-sensing. The ability to image single NV color centers in a nanodiamond and manipulate NV electron spin optically under ambient condition is the main driving force behind developments in nanoscale sensing and novel imaging techniques. In this article we discuss current status on the applications of fluorescent nanodiamonds (FND) for optical super resolution nanoscopy, magneto-optical (spin-assisted) sub-wavelength localization and imaging. We present emerging applications such as single molecule spin imaging, nanoscale imaging of biomagnetic fields, sensing molecular fluctuations and temperatures in live cellular environments. We summarize other current advances and future prospects of NV diamond for imaging and sensing pertaining to bio-medical applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

Color planner for designers based on color emotions

Science.gov (United States)

Cheng, Ka-Man; Xin, John H.; Taylor, Gail

2002-06-01

During the color perception process, an associated feeling or emotion is induced in our brains, and this kind of emotion is termed as 'color emotion.' The researchers in the field of color emotions have put many efforts in quantifying color emotions with the standard color specifications and evaluating the influence of hue, lightness and chroma to the color emotions of human beings. In this study, a color planner was derived according to these findings so that the correlation of color emotions and standard color specifications was clearly indicated. Since people of different nationalities usually have different color emotions as different cultural and traditional backgrounds, the subjects in this study were all native Hong Kong Chinese and the color emotion words were all written in Chinese language in the visual assessments. Through the color planner, the designers from different areas, no matter fashion, graphic, interior or web site etc., can select suitable colors for inducing target color emotions to the customers or product-users since different colors convey different meanings to them. In addition, the designers can enhance the functionality and increase the attractiveness of their designed products by selecting suitable colors.

Radiation-induced centers in inorganic glasses

International Nuclear Information System (INIS)

Brekhovskikh, S.M.; Tyul'nin, V.A.

1988-01-01

The nature, structure and formation mechanisms of radiation-induced colour centers, EPR, luminescence, generated ionizing radiation in nonorganic oxide glasses are considered. Experimental material covering both fundamental aspects of radiation physics and glass chemistry, and aspects intimately connected with the creation of new materials with the given radiation-spectral characteristics, with possibilities to prepare radiation-stable and radiation-sensitive glasses is systematized and generalized. Considerable attention is paid to the detection of radiation-induced center binding with composition, glass structures redox conditions for their synthesis. Some new possibilities of practical application of glasses with radiation-induced centers, in particular, to record optical information are reflected in the paper

Studies on the radiation-induced coloration mechanism of the cellulose triacetate film dosimeter

International Nuclear Information System (INIS)

Matsuda, Koji; Nagai, Siro

1991-01-01

The species responsible for the coloration of the cellulose triacetate (CTA) film dosemeter have been studied using ultraviolet, electron spin resonance, infrared and gas chromatographic techniques. The post-irradiation change in the optical density at 280 nm indicates that the coloration occurs not only during irradiation (in situ coloration) but also after irradiation (post-irradiation coloration) and that in situ coloration is due to unstable and stable components. The species responsible for the unstable component of in situ coloration are ascribed to the radicals produced from CTA molecules and those for the stable component to the radiolysis products from CTA and triphenyl phosphate contained in the dosimeter. On the other hand, post-irradiation coloration is attributed to the formation of carbonyl groups in CTA molecules, which is induced by reaction with NO 2 produced by irradiation of air. (author)

Study of the fluorescence blinking behavior of single F2 color centers in LiF crystal

International Nuclear Information System (INIS)

Boichenko, S V; Koenig, K; Zilov, S A; Dresvianskiy, V P; Rakevich, A L; Kuznetsov, A V; Bartul, A V; Martynovich, E F; Voitovich, A P

2014-01-01

Using confocal fluorescence microscopy technique, we observed experimentally the luminescence of single F 2 color centers in LiF crystal. It is disclosed that the fluorescence shows blinking behavior. It is shown that this phenomenon is caused by the F 2 center reorientation occurring during the experiment. The ratio of luminescence intensities of differently oriented centers is assessed theoretically for two different experiment configurations. The calculated ratios are in fine agreement with experimental result

Laser-induced plasmas in air studied using two-color interferometry

International Nuclear Information System (INIS)

Yang, Zefeng; Wu, Jian; Li, Xingwen; Han, Jiaxun; Jia, Shenli; Qiu, Aici; Wei, Wenfu

2016-01-01

Temporally and spatially resolved density profiles of Cu atoms, electrons, and compressed air, from laser-induced copper plasmas in air, are measured using fast spectral imaging and two-color interferometry. From the intensified CCD images filtered by a narrow-band-pass filter centered at 515.32 nm, the Cu atoms expansion route is estimated and used to determine the position of the fracture surface between the Cu atoms and the air. Results indicate that the Cu atoms density at distances closer to the target (0–0.4 mm) is quite low, with the maximum density appearing at the edge of the plasma's core being ∼4.6 × 10"2"4" m"−"3 at 304 ns. The free electrons are mainly located in the internal region of the plume, which is supposed to have a higher temperature. The density of the shock wave is (4–6) × 10"2"5" m"−"3, corresponding to air compression of a factor of 1.7–2.5.

Laser-induced plasmas in air studied using two-color interferometry

Energy Technology Data Exchange (ETDEWEB)

Yang, Zefeng; Wu, Jian, E-mail: jxjawj@mail.xjtu.edu.cn; Li, Xingwen; Han, Jiaxun; Jia, Shenli; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Shaanxi 710049 (China); Wei, Wenfu [School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031 (China)

2016-08-15

Temporally and spatially resolved density profiles of Cu atoms, electrons, and compressed air, from laser-induced copper plasmas in air, are measured using fast spectral imaging and two-color interferometry. From the intensified CCD images filtered by a narrow-band-pass filter centered at 515.32 nm, the Cu atoms expansion route is estimated and used to determine the position of the fracture surface between the Cu atoms and the air. Results indicate that the Cu atoms density at distances closer to the target (0–0.4 mm) is quite low, with the maximum density appearing at the edge of the plasma's core being ∼4.6 × 10{sup 24 }m{sup −3} at 304 ns. The free electrons are mainly located in the internal region of the plume, which is supposed to have a higher temperature. The density of the shock wave is (4–6) × 10{sup 25 }m{sup −3}, corresponding to air compression of a factor of 1.7–2.5.

The color-flavor transformation of induced QCD

CERN Document Server

Shnir, Ya M

2002-01-01

The color-flavor transformation is applied to the $U(N_c)$ lattice model, in which the gauge theory is induced by the chiral scalar field associated with an elementary plaquette. The flavor degrees of freedom are related with the number of generations of the auxiliary field, and flavor components of each generation are associated with all the plaquettes having a lattice site in common. The property of the dual color-flavor transformed theory, which is expressed in terms of the gauge singlets, are analyzed in $d=2$ and $d=3$ dimensions. The saddle point solution of the model in the large-$N_c$ limit is discussed. The correlations between the plaquettes, which are described by the dual theory, allows to define the dual lattice. In $d=3$ dimensions it is made of tetradecahedra which correspond to the cubes of the original lattice. The continuum limit of $d=2$ effective theory is discussed.

The color-flavor transformation of induced QCD

International Nuclear Information System (INIS)

Shnir, Ya.

2002-09-01

The color-flavor transformation is applied to the U(N c ) lattice model, in which the gauge theory is induced by the chiral scalar field associated with an elementary plaquette. The flavor degrees of freedom are related with the number of generations of the auxiliary field, and flavor components of each generation are associated with all the plaquettes having a lattice site in common. The property of the dual color-flavor transformed theory, which is expressed in terms of the gauge singlets, are analyzed in d=2 and d=3 dimensions. The saddle point solution of the model in the large-N c limit is discussed. The correlations between the plaquettes, which are described by the dual theory, allows to define the dual lattice. In d=3 dimensions it is made of tetradecahedra which correspond to the cubes of the original lattice. The continuum limit of d=2 effective theory is discussed. (author)

Laser-evoked coloration in polymers

International Nuclear Information System (INIS)

Zheng, H.Y.; Rosseinsky, David; Lim, G.C.

2005-01-01

Laser-evoked coloration in polymers has long been a major aim of polymer technology for potential applications in product surface decoration, marking personalised images and logos. However, the coloration results reported so far were mostly attributed to laser-induced thermal-chemical reactions. The laser-irradiated areas are characterized with grooves due to material removal. Furthermore, only single color was laser-induced in any given polymer matrix. To induce multiple colors in a given polymer matrix with no apparent surface material removal is most desirable and challenging and may be achieved through laser-induced photo-chemical reactions. However, little public information is available at present. We report that two colors of red and green have been produced on an initially transparent CPV/PVA samples through UV laser-induced photo-chemical reactions. This is believed the first observation of laser-induced multiple-colors in the given polymer matrix. It is believed that the colorants underwent photo-effected electron transfer with suitable electron donors from the polymers to change from colorless bipyridilium Bipm 2+ to the colored Bipm + species. The discovery may lead to new approaches to the development of laser-evoked multiple coloration in polymers

Spiral Waves and Multiple Spatial Coherence Resonances Induced by Colored Noise in Neuronal Network

International Nuclear Information System (INIS)

Tang Zhao; Li Yuye; Xi Lei; Jia Bing; Gu Huaguang

2012-01-01

Gaussian colored noise induced spatial patterns and spatial coherence resonances in a square lattice neuronal network composed of Morris-Lecar neurons are studied. Each neuron is at resting state near a saddle-node bifurcation on invariant circle, coupled to its nearest neighbors by electronic coupling. Spiral waves with different structures and disordered spatial structures can be alternately induced within a large range of noise intensity. By calculating spatial structure function and signal-to-noise ratio (SNR), it is found that SNR values are higher when the spiral structures are simple and are lower when the spatial patterns are complex or disordered, respectively. SNR manifest multiple local maximal peaks, indicating that the colored noise can induce multiple spatial coherence resonances. The maximal SNR values decrease as the correlation time of the noise increases. These results not only provide an example of multiple resonances, but also show that Gaussian colored noise play constructive roles in neuronal network. (general)

Electrolytic coloration of air-grown sodium fluoride crystals

International Nuclear Information System (INIS)

Gu Hongen; Han Li; Song Cuiying; Guo Meili; Wang Na

2007-01-01

Air-grown sodium fluoride crystals were colored electrolytically by using a pointed cathode at various temperatures and electric field strengths, which should mainly benefit appropriate coloration temperatures and electric field strengths. O 2 - , F, M, N 1 , N 2 color centers and O 2- -F + complexes were produced in the colored crystals. Current-time curves for the electrolytic colorations were given, and activation energy for the V color center migration was determined. The formation of the color centers was explained

Ghost responses of the FitzHugh–Nagumo system induced by colored noise

International Nuclear Information System (INIS)

Bordet, M.; Morfu, S.; Marquié, P.

2015-01-01

We investigate both numerically and experimentally how the triggering of Ghost Stochastic Resonance is affected by colored noise in a FitzHugh–Nagumo circuit. It is experimentally shown that when the circuit is excited with a bichromatic signal, weak colored noise can induce a response with a main ghost frequency which is not present in the excitation. We analyze the occurrence of this ghost frequency versus the noise intensity and the correlation time of the colored noise. Numerical simulations and experiments confirm that for larger noise correlation time, submultiples of this ghost frequency dominate the system response while the previous expected ghost frequency is less observed

Quark condensation, induced symmetry breaking and color superconductivity at high density

International Nuclear Information System (INIS)

Langfeld, Kurt; Rho, Mannque

1999-01-01

The phase structure of hadronic matter at high density relevant to the physics of compact stars and relativistic heavy-ion collisions is studied in a low-energy effective quark theory. The relevant phases that figure are (1) chiral condensation, (2) diquark color condensation (color superconductivity) and (3) induced Lorentz-symmetry breaking (''ISB''). For a reasonable strength for the effective four-Fermi current-current interaction implied by the low-energy effective quark theory for systems with a Fermi surface we find that the ''ISB'' phase sets in together with chiral symmetry restoration (with the vanishing quark condensate) at a moderate density while color superconductivity associated with scalar diquark condensation is pushed up to an asymptotic density. Consequently, color superconductivity seems rather unlikely in heavy-ion collisions although it may play a role in compact stars. Lack of confinement in the model makes the result of this analysis only qualitative but the hierarchy of the transitions we find seems to be quite robust

Food Color Induced Hepatotoxicity in Swiss Albino Rats, Rattus norvegicus

OpenAIRE

Saxena, Beenam; Sharma, Shiv

2015-01-01

Objective: Certain dietary constituents can induce toxicity and play a critical role in the development of several hepatic disorders. Tartrazine, metanil yellow and sunset yellow are widely used azo dyes in food products, so the present study is aimed to investigate the food color induced hepatotoxicity in Swiss albino rats. Materials and Methods: Swiss albino rats were divided into four groups, each group having six animals. Group I served as control, Group II, Group III and Group IV were ad...

Structural coloration of metallic surfaces with micro/nano-structures induced by elliptical vibration texturing

Science.gov (United States)

Yang, Yang; Pan, Yayue; Guo, Ping

2017-04-01

Creating orderly periodic micro/nano-structures on metallic surfaces, or structural coloration, for control of surface apparent color and optical reflectivity has been an exciting research topic over the years. The direct applications of structural coloration include color marking, display devices, and invisibility cloak. This paper presents an efficient method to colorize metallic surfaces with periodic micro/nano-gratings using elliptical vibration texturing. When the tool vibration is coupled with a constant cutting velocity, controlled periodic ripples can be generated due to the overlapping tool trajectory. These periodic ripples with a wavelength near visible spectrum can act as micro-gratings to introduce iridescent colors. The proposed technique also provides a flexible method for color marking of metallic surfaces with arbitrary patterns and images by precise control of the spacing distance and orientation of induced micro/nano-ripples. Theoretical analysis and experimental results are given to demonstrate structural coloration of metals by a direct mechanical machining technique.

Content-Based Image Retrieval Benchmarking: Utilizing color categories and color distributions

NARCIS (Netherlands)

van den Broek, Egon; Kisters, Peter M.F.; Vuurpijl, Louis G.

From a human centered perspective three ingredients for Content-Based Image Retrieval (CBIR) were developed. First, with their existence confirmed by experimental data, 11 color categories were utilized for CBIR and used as input for a new color space segmentation technique. The complete HSI color

Luminescence and color center distributions in K3YB6O12:Ce3+ phosphor

International Nuclear Information System (INIS)

Yang, Li; Wan, Yingpeng; Weng, Honggen; Huang, Yanlin; Chen, Cuili; Seo, Hyo Jin

2016-01-01

Polycrystalline Ce 3+ -doped K 3 YB 6 O 12 (1–14 mol%) phosphors were prepared by facile chemical sol–gel synthesis. The phase formation of the phosphors was confirmed by x-ray powder diffraction (XRD) analysis. The photoluminescence excitation spectra (PLE), emission spectra (PL) and the luminescence decay curves were tested. Under the near-UV light, the phosphors present the emission from blue color to yellowish green due to the allowed 4 f  –5 d transitions of Ce 3+ ions. The absolute quantum efficiency (QE) of K 3 YB 6 O 12 :Ce 3+ can reach 53% under the excitation of near-UV light. The luminescence thermal quenching of the phosphor was investigated by the temperature-dependent spectra. The crystallographic site of Ce 3+ ions in the lattice was identified and discussed on the basis of luminescence characteristics and structural data. There is only one isolated Ce 3+ center occupying the Y(II) sites in the lightly doped samples presenting a typical doublet emission profile. While the Ce 3+ multi-centers could be created with the enhancement of the doping levels, which could induce the distinct red-shift of the spectra due to the dipole–dipole interactions. The result in this work could be useful for the further investigation of other rare earth ions in this host. (paper)

Effects of chromatic image statistics on illumination induced color differences.

Science.gov (United States)

Lucassen, Marcel P; Gevers, Theo; Gijsenij, Arjan; Dekker, Niels

2013-09-01

We measure the color fidelity of visual scenes that are rendered under different (simulated) illuminants and shown on a calibrated LCD display. Observers make triad illuminant comparisons involving the renderings from two chromatic test illuminants and one achromatic reference illuminant shown simultaneously. Four chromatic test illuminants are used: two along the daylight locus (yellow and blue), and two perpendicular to it (red and green). The observers select the rendering having the best color fidelity, thereby indirectly judging which of the two test illuminants induces the smallest color differences compared to the reference. Both multicolor test scenes and natural scenes are studied. The multicolor scenes are synthesized and represent ellipsoidal distributions in CIELAB chromaticity space having the same mean chromaticity but different chromatic orientations. We show that, for those distributions, color fidelity is best when the vector of the illuminant change (pointing from neutral to chromatic) is parallel to the major axis of the scene's chromatic distribution. For our selection of natural scenes, which generally have much broader chromatic distributions, we measure a higher color fidelity for the yellow and blue illuminants than for red and green. Scrambled versions of the natural images are also studied to exclude possible semantic effects. We quantitatively predict the average observer response (i.e., the illuminant probability) with four types of models, differing in the extent to which they incorporate information processing by the visual system. Results show different levels of performance for the models, and different levels for the multicolor scenes and the natural scenes. Overall, models based on the scene averaged color difference have the best performance. We discuss how color constancy algorithms may be improved by exploiting knowledge of the chromatic distribution of the visual scene.

Physiologically induced color-pattern changes in butterfly wings: mechanistic and evolutionary implications.

Science.gov (United States)

Otaki, Joji M

2008-07-01

A mechanistic understanding of the butterfly wing color-pattern determination can be facilitated by experimental pattern changes. Here I review physiologically induced color-pattern changes in nymphalid butterflies and their mechanistic and evolutionary implications. A type of color-pattern change can be elicited by elemental changes in size and position throughout the wing, as suggested by the nymphalid groundplan. These changes of pattern elements are bi-directional and bi-sided dislocation toward or away from eyespot foci and in both proximal and distal sides of the foci. The peripheral elements are dislocated even in the eyespot-less compartments. Anterior spots are more severely modified, suggesting the existence of an anterior-posterior gradient. In one species, eyespots are transformed into white spots with remnant-like orange scales, and such patterns emerge even at the eyespot-less "imaginary" foci. A series of these color-pattern modifications probably reveal "snap-shots" of a dynamic morphogenic signal due to heterochronic uncoupling between the signaling and reception steps. The conventional gradient model can be revised to account for these observed color-pattern changes.

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.

Colored Contact Lens Dangers

Medline Plus

Full Text Available ... Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Eye Health ... Leer en Español: Peligros asociados con los lentes de contacto de color Sep. 26, ...

Effect of air annealing on the color center in Yb:Y3Al5O12 transparent ceramics with MgO as sintering additive

Science.gov (United States)

Lu, Zhongwen; Lu, Tiecheng; Wei, Nian; Zhang, Wei; Ma, Benyuan; Qi, Jianqi; Guan, Yongbing; Chen, Xingtao; Wu, Huajun; Zhao, Yu

2015-09-01

High quality Yb:Y3Al5O12 (YAG) transparent ceramics were fabricated by vacuum sintering with MgO as sintering aids. The Yb:YAG samples were annealed at 1250-1450 °C for 20 h in air. The experimental results showed that the transparency of Yb:YAG samples declined markedly with the annealing temperatures of 1250-1450 °C. The samples became increasingly orange-yellow in color with the increase of annealing temperature. The potential reasons of discoloration were discussed for the first time. It was attributed to the complex color center [Mg2+F+] formed during the annealing, which was evidenced by optical absorption in the range of 300-500 nm wavelength and the presence of an electron spin resonance (ESR) line at g = 1.9806. The formation mechanism of the complex color center was explained in detail. The complex color center can be eliminated after post-HIP (hot isostatic pressing). And by air annealing and post-HIP, the transmittance of the samples increased from 80.3% to 83.4%.

Soft X-ray imaging by optically stimulated luminescence from color centers in lithium fluoride

Energy Technology Data Exchange (ETDEWEB)

Bonfigli, F. [ENEA, C.R. Frascati, Via E. Fermi, 45, 00044 Frascati (Rome) (Italy)], E-mail: bonfigli@frascati.enea.it; Almaviva, S.; Baldacchini, G.; Bollanti, S.; Flora, F.; Lai, A.; Montereali, R.M. [ENEA, C.R. Frascati, Via E. Fermi, 45, 00044 Frascati (Rome) (Italy); Nichelatti, E. [ENEA, C.R. Casaccia, Via Anguillarese 301, 00060 S.Maria di Galeria (Rome) (Italy); Tomassetti, G.; Ritucci, A.; Reale, L. [Universita de L' Aquila e INFN, Dip. di Fisica, Coppito, L' Aquila (Italy); Faenov, A. Ya.; Pikuz, T.A. [MISDC of VNIIFTRI Mendeleevo, Moscow region, 141570 (Russian Federation); Larciprete, R. [ISC-CNR, Sezione Montelibretti, Via Salaria, Km. 29.3, 00016 Monterotondo Scalo (Rome) (Italy); Gregoratti, L.; Kiskinova, M. [Sincrotrone Trieste, S. S. 14, Km. 163.5, 34012 Basovizza (TS) (Italy)

2007-07-15

An innovative X-ray imaging detector based on Optically Stimulated Luminescence from color centers in lithium fluoride is presented. Regular photoluminescent patterns produced on LiF samples by different intense X-ray sources, like synchrotrons, laser plasma sources and a capillary discharge laser have been investigated by a Confocal Laser Scanning Microscope. The use of a LiF-based imaging plate for X-ray microscopy is also discussed showing microradiographies of small animals.

Study of the spectral and energy characteristics of lasing in the green spectral region by lithium fluoride with radiation color centers

Energy Technology Data Exchange (ETDEWEB)

Voitovich, A.P.; Kalinov, V.S.; Mikhnov, S.A.; Ovseichuk, S.I.

1987-06-01

The spectral and energy characteristics of lasers utilizing lithium fluoride with F2 and F3(+) color centers in transverse and longitudinal pumping schemes are studied. The feasibility of obtaining stable narrow-band radiation in the 510-570 nm range using a selective resonator is demonstrated. Consideration is given to the effect of lithium-fluoride crystal processing by excimer laser radiation at a wavelength of 308 nm on the spectroscopic and lasing characteristics of the F3(+) color center. After this processing, the laser efficiency in the green spectral region increases by more than a factor of two (reaching an efficiency of 14 percent). 7 references.

Using clinical simulation centers to test design interventions: a pilot study of lighting and color modifications.

Science.gov (United States)

Gray, Whitney Austin; Kesten, Karen S; Hurst, Stephen; Day, Tama Duffy; Anderko, Laura

2012-01-01

The aim of this pilot study was to test design interventions such as lighting, color, and spatial color patterning on nurses' stress, alertness, and satisfaction, and to provide an example of how clinical simulation centers can be used to conduct research. The application of evidence-based design research in healthcare settings requires a transdisciplinary approach. Integrating approaches from multiple fields in real-life settings often proves time consuming and experimentally difficult. However, forums for collaboration such as clinical simulation centers may offer a solution. In these settings, identical operating and patient rooms are used to deliver simulated patient care scenarios using automated mannequins. Two identical rooms were modified in the clinical simulation center. Nurses spent 30 minutes in each room performing simulated cardiac resuscitation. Subjective measures of nurses' stress, alertness, and satisfaction were collected and compared between settings and across time using matched-pair t-test analysis. Nurses reported feeling less stressed after exposure to the experimental room than nurses who were exposed to the control room (2.22, p = .03). Scores post-session indicated a significant reduction in stress and an increase in alertness after exposure to the experimental room as compared to the control room, with significance levels below .10. (Change in stress scores: 3.44, p = .069); (change in alertness scores: 3.6, p = .071). This study reinforces the use of validated survey tools to measure stress, alertness, and satisfaction. Results support human-centered design approaches by evaluating the effect on nurses in an experimental setting.

Colored Contact Lens Dangers

Medline Plus

Full Text Available ... 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 ... Service For Advertisers For Media Ophthalmology Job Center © American ...

Use of Color in Child Care Environments: Application of Color for Wayfinding and Space Definition in Alabama Child Care Environments.

Science.gov (United States)

Read, Marilyn A.

2003-01-01

Compared the use of color in physical design features associated with the exterior and interior designs of 101 child care centers in Alabama. Found that color was evidenced on the exterior of the centers at just over half of the sample. The interior environments had warm colors and bright accents in the setting; however, the majority of centers…

Multicolor Fluorescence Writing Based on Host-Guest Interactions and Force-Induced Fluorescence-Color Memory.

Science.gov (United States)

Matsunaga, Yuki; Yang, Jye-Shane

2015-06-26

A new strategy is reported for multicolor fluorescence writing on thin solid films with mechanical forces. This concept is illustrated by the use of a green-fluorescent pentiptycene derivative 1, which forms variably colored fluorescent exciplexes: a change from yellow to red was observed with anilines, and fluorescence quenching (a change to black) occurred in the presence of benzoquinone. Mechanical forces, such as grinding and shearing, induced a crystalline-to-amorphous phase transition in both the pristine and guest-adsorbed solids that led to a change in the fluorescence color (mechanofluorochromism) and a memory of the resulting color. Fluorescence drawings of five or more colors were created on glass or paper and could be readily erased by exposure to air and dichloromethane fumes. The structural and mechanistic aspects of the observations are also discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrolytic coloration and spectral properties of hydroxyl-doped potassium chloride single crystals

International Nuclear Information System (INIS)

Gu Hongen; Wu Yanru

2011-01-01

Hydroxyl-doped potassium chloride single crystals are colored electrolytically at various temperatures and voltages using a pointed cathode and a flat anode. Characteristic OH - spectral band is observed in the absorption spectrum of uncolored single crystal. Characteristic O - , OH - , U, V 2 , V 3 , O 2- -V a + , F, R 2 and M spectral bands are observed simultaneously in absorption spectra of colored single crystals. Current-time curve for electrolytic coloration of hydroxyl-doped potassium chloride single crystal and its relationship with electrolytic coloration process are given. Production and conversion of color centers are explained. - Highlights: → Expanded the traditional electrolysis method. → Hydroxyl-doped potassium chloride crystals were colored electrolytically for the first time. → Useful V, F and F-aggregate color centers were produced in colored crystals. → V color centers were produced directly and F and F-aggregate color centers indirectly.

Electrolytic coloration and spectral properties of hydroxyl-doped potassium bromide single crystals

International Nuclear Information System (INIS)

Qi, Lan; Song, Cuiying; Gu, Hongen

2013-01-01

Hydroxyl-doped potassium bromide single crystals are colored electrolytically at various temperatures and voltages by using a pointed cathode and a flat anode. The characteristic OH − spectral band is observed in absorption spectrum of uncolored single crystal. The characteristic O − , OH − , U, V 2 , O 2− −V a + , M L1 , F and M spectral bands are observed simultaneously in absorption spectra of colored single crystals. Current–time curve for electrolytic coloration of hydroxyl-doped potassium bromide single crystal and its relationship with electrolytic coloration processes are given. Production and conversion of color centers are explained. - Highlights: ► We expanded the traditional electrolysis method. ► Hydroxyl-doped potassium bromide crystals were colored electrolytically for the first time. ► Useful V, F and F-aggregate color centers were produced in colored crystals. ► V color centers were produced directly and F as well as F-aggregate color centers indirectly.

Surface color from boundaries: a new 'watercolor' illusion.

Science.gov (United States)

Pinna, B; Brelstaff, G; Spillmann, L

2001-09-01

A colored line flanking a darker border will appear to assimilate its color onto the enclosed white area over distances of up to 45 deg (the Watercolor Effect). This coloration is uniform and complete within 100 ms. We found that thin (6 arcmin), winding inducing lines with different contrasts to the ground are generally more effective than thick, straight, and equiluminant lines. Blue and red lines induce the strongest effects, but watercolor spreading may also be seen with green and yellow. On a white background, color spreading is stronger than on chromatic, gray or black backgrounds. Little or no color is perceived when a narrow white zone (gap) is inserted in between the two inducing lines. However, chains of colored dots instead of continuous lines suffice to produce spreading. Edge-induced color is also observed when the two colored lines are presented dichoptically, suggesting a cortical origin. The Watercolor Effect described here may serve to enhance figure-ground segregation by imparting surface color onto the enclosed area, and to promote grouping between distant stimulus elements. As a grouping factor, watercolor coloration wins over proximity. Assimilative color spreading may arise in two steps: First, weakening of the contour by lateral inhibition between differentially activated edge cells (local diffusion); and second, unbarriered flow of color onto the enclosed area (global diffusion).

Mechanisms of two-color laser-induced field-free molecular orientation.

Science.gov (United States)

Spanner, Michael; Patchkovskii, Serguei; Frumker, Eugene; Corkum, Paul

2012-09-14

Two mechanisms of two-color (ω+2ω) laser-induced field-free molecular orientation, based on the hyperpolarizability and ionization depletion, are explored and compared. The CO molecule is used as a computational example. While the hyperpolarizability mechanism generates small amounts of orientation at intensities below the ionization threshold, ionization depletion quickly becomes the dominant mechanism as soon as ionizing intensities are reached. Only the ionization mechanism leads to substantial orientation (e.g., on the order of ≳0.1). For intensities typical of laser-induced molecular alignment and orientation experiments, the two mechanisms lead to robust, characteristic timings of the field-free orientation wave-packet revivals relative to the alignment revivals and the revival time. The revival timings can be used to detect the active orientation mechanism experimentally.

Direct detection of light dark matter and solar neutrinos via color center production in crystals

OpenAIRE

Budnik, Ranny; Cheshnovsky, Ori; Slone, Oren; Volansky, Tomer

2018-01-01

We propose a new low-threshold direct-detection concept for dark matter and for coherent nuclear scattering of solar neutrinos, based on the dissociation of atoms and subsequent creation of color center type defects within a lattice. The novelty in our approach lies in its ability to detect single defects in a macroscopic bulk of material. This class of experiments features ultra-low energy thresholds which allows for the probing of dark matter as light as O(10) MeV through nuclear scattering...

A Color-Opponency Based Biological Model for Color Constancy

Directory of Open Access Journals (Sweden)

Yongjie Li

2011-05-01

Full Text Available Color constancy is the ability of the human visual system to adaptively correct color-biased scenes under different illuminants. Most of the existing color constancy models are nonphysiologically plausible. Among the limited biological models, the great majority is Retinex and its variations, and only two or three models directly simulate the feature of color-opponency, but only of the very earliest stages of visual pathway, i.e., the single-opponent mechanisms involved at the levels of retinal ganglion cells and lateral geniculate nucleus (LGN neurons. Considering the extensive physiological evidences supporting that both the single-opponent cells in retina and LGN and the double-opponent neurons in primary visual cortex (V1 are the building blocks for color constancy, in this study we construct a color-opponency based color constancy model by simulating the opponent fashions of both the single-opponent and double-opponent cells in a forward manner. As for the spatial structure of the receptive fields (RF, both the classical RF (CRF center and the nonclassical RF (nCRF surround are taken into account for all the cells. The proposed model was tested on several typical image databases commonly used for performance evaluation of color constancy methods, and exciting results were achieved.

Two-color planar laser-induced fluorescence thermometry in aqueous solutions

International Nuclear Information System (INIS)

Robinson, G. Andrew; Lucht, Robert P.; Laurendeau, Normand M.

2008-01-01

We demonstrate a two-color planar laser-induced fluorescence technique for obtaining two-dimensional temperature images in water. For this method, a pulsed Nd:YAG laser at 532 nm excites a solution of temperature-sensitive rhodamine 560 and temperature-insensitive sulforhodamine 640. The resulting emissions are optically separated through filters and detected via a charged-couple device (CCD) camera system. A ratio of the two images yields temperature images independent of incident irradiance. An uncertainty in temperature of ±1.4 deg. C is established at the 95% confidence interval

Scanning Color Laser Microscope

Science.gov (United States)

Awamura, D.; Ode, T.; Yonezawa, M.

1988-01-01

A confocal color laser microscope which utilizes a three color laser light source (Red: He-Ne, Green: Ar, Blue: Ar) has been developed and is finding useful applications in the semiconductor field. The color laser microscope, when compared to a conventional microscope, offers superior color separation, higher resolution, and sharper contrast. Recently some new functions including a Focus Scan Memory, a Surface Profile Measurement System, a Critical Dimension Measurement system (CD) and an Optical Beam Induced Current Function (OBIC) have been developed for the color laser microscope. This paper will discuss these new features.

Analysis of oxide formation induced by UV laser coloration of stainless steel

Energy Technology Data Exchange (ETDEWEB)

Li, Z.L., E-mail: zlli@SIMTech.a-star.edu.sg [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075 (Singapore); Zheng, H.Y.; Teh, K.M.; Liu, Y.C.; Lim, G.C. [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075 (Singapore); Seng, H.L.; Yakovlev, N.L. [Institute of Materials Research and Engineering, 3 Research Link, 117602 (Singapore)

2009-12-15

Laser-induced coloration on metal surfaces has important applications in product identification, enhancing styles and aesthetics. The color generation is the result of controlled surface oxidation during laser beam interaction with the metal surfaces. In this study, we aim to obtain in-depth understanding of the oxide formation process when an UV laser beam interacts with stainless steel in air. The oxide layer is analysed by means of optical microscopy, scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometer (TOF-SIMS). TOF-SIMS results clearly show the formation of duplex oxide structures. The duplex structure includes an inner layer of Cr oxide solution and an outer layer of Fe oxide solution. The oxide layer thickness increased as the results of Fe diffusion to surface during multiple laser scanning passes.

Analysis of oxide formation induced by UV laser coloration of stainless steel

International Nuclear Information System (INIS)

Li, Z.L.; Zheng, H.Y.; Teh, K.M.; Liu, Y.C.; Lim, G.C.; Seng, H.L.; Yakovlev, N.L.

2009-01-01

Laser-induced coloration on metal surfaces has important applications in product identification, enhancing styles and aesthetics. The color generation is the result of controlled surface oxidation during laser beam interaction with the metal surfaces. In this study, we aim to obtain in-depth understanding of the oxide formation process when an UV laser beam interacts with stainless steel in air. The oxide layer is analysed by means of optical microscopy, scanning electron microscopy (SEM) and time-of-flight secondary ion mass spectrometer (TOF-SIMS). TOF-SIMS results clearly show the formation of duplex oxide structures. The duplex structure includes an inner layer of Cr oxide solution and an outer layer of Fe oxide solution. The oxide layer thickness increased as the results of Fe diffusion to surface during multiple laser scanning passes.

Color formation study of irradiated polymers by electron beam; Estudo da formacao de cor em polimeros irradiaddos com feixe de eletrons

Energy Technology Data Exchange (ETDEWEB)

Nardi, Daniela Teves

2004-07-01

Color formation on national and commercial polymers (polymethyl methacrylate, polystyrene and polycarbonate) irradiated by electrons beam was investigated by colorimetry (CIELab), electron spectroscopy resonance (ESR), photoacoustic infrared spectroscopy (FTIR-PAS) and differential exploratory calorimetry (DSC). The heat effect on colorimetric properties was investigated after heating (110 deg C for 1 hour) of irradiated polymers at 150 kGy. The rule of oxygen in colorimetric properties of irradiated polycarbonate was investigated in the air presence and absence (p = 10{sup -3} mmHg). The visual aspect did not agree with colorimetric parameters only for polycarbonate. Yellow color and darkness were induced by radiation for all studied polymers varying only the intensity and behavior in function of post-irradiation time and heating. Polymethyl methacrylate and polystyrene ESR spectra showed that radicals could be responsible by yellow color centers. Wherever, in polycarbonate, color centers were not due radical species. The nature of color centers for any studied polymer was not study by FTIR-PAS because there were no changes in FTIR-PAS spectra neither in function of dose nor heating. Polycarbonate was the most radiosensible and polystyrene was the most radioresistant of all studied polymers in concern of colorimetric properties. (author)

Colored Contact Lens Dangers

Medline Plus

Full Text Available ... MD, professor of ophthalmology at Case Western Reserve University in Cleveland. "This is far from the truth." ... 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 ... Service For Advertisers For Media Ophthalmology Job Center © American ...

Memory color effect induced by familiarity of brand logos.

Science.gov (United States)

Kimura, Atsushi; Wada, Yuji; Masuda, Tomohiro; Goto, Sho-Ichi; Tsuzuki, Daisuke; Hibino, Haruo; Cai, Dongsheng; Dan, Ippeita

2013-01-01

When people are asked to adjust the color of familiar objects such as fruits until they appear achromatic, the subjective gray points of the objects are shifted away from the physical gray points in a direction opposite to the memory color (memory color effect). It is still unclear whether the discrepancy between memorized and actual colors of objects is dependent on the familiarity of the objects. Here, we conducted two experiments in order to examine the relationship between the degree of a subject's familiarity with objects and the degree of the memory color effect by using logographs of food and beverage companies. In Experiment 1, we measured the memory color effects of logos which varied in terms of their familiarity (high, middle, or low). Results demonstrate that the memory color effect occurs only in the high-familiarity condition, but not in the middle- and low-familiarity conditions. Furthermore, there is a positive correlation between the memory color effect and the actual number of domestic stores of the brand. In Experiment 2, we assessed the semantic association between logos and food/beverage names by using a semantic priming task to elucidate whether the memory color effect of logos relates to consumer brand cognition, and found that the semantic associations between logos and food/beverage names in the high-familiarity brands were stronger than those in the low-familiarity brands only when the logos were colored correctly, but not when they were appropriately or inappropriately colored, or achromatic. The current results provide behavioral evidence of the relationship between the familiarity of objects and the memory color effect and suggest that the memory color effect increases with the familiarity of objects, albeit not constantly.

Memory Color Effect Induced by Familiarity of Brand Logos

Science.gov (United States)

Kimura, Atsushi; Wada, Yuji; Masuda, Tomohiro; Goto, Sho-ichi; Tsuzuki, Daisuke; Hibino, Haruo; Cai, Dongsheng; Dan, Ippeita

2013-01-01

Background When people are asked to adjust the color of familiar objects such as fruits until they appear achromatic, the subjective gray points of the objects are shifted away from the physical gray points in a direction opposite to the memory color (memory color effect). It is still unclear whether the discrepancy between memorized and actual colors of objects is dependent on the familiarity of the objects. Here, we conducted two experiments in order to examine the relationship between the degree of a subject’s familiarity with objects and the degree of the memory color effect by using logographs of food and beverage companies. Methods and Findings In Experiment 1, we measured the memory color effects of logos which varied in terms of their familiarity (high, middle, or low). Results demonstrate that the memory color effect occurs only in the high-familiarity condition, but not in the middle- and low-familiarity conditions. Furthermore, there is a positive correlation between the memory color effect and the actual number of domestic stores of the brand. In Experiment 2, we assessed the semantic association between logos and food/beverage names by using a semantic priming task to elucidate whether the memory color effect of logos relates to consumer brand cognition, and found that the semantic associations between logos and food/beverage names in the high-familiarity brands were stronger than those in the low-familiarity brands only when the logos were colored correctly, but not when they were appropriately or inappropriately colored, or achromatic. Conclusion The current results provide behavioral evidence of the relationship between the familiarity of objects and the memory color effect and suggest that the memory color effect increases with the familiarity of objects, albeit not constantly. PMID:23874638

Memory color effect induced by familiarity of brand logos.

Directory of Open Access Journals (Sweden)

Atsushi Kimura

Full Text Available When people are asked to adjust the color of familiar objects such as fruits until they appear achromatic, the subjective gray points of the objects are shifted away from the physical gray points in a direction opposite to the memory color (memory color effect. It is still unclear whether the discrepancy between memorized and actual colors of objects is dependent on the familiarity of the objects. Here, we conducted two experiments in order to examine the relationship between the degree of a subject's familiarity with objects and the degree of the memory color effect by using logographs of food and beverage companies.In Experiment 1, we measured the memory color effects of logos which varied in terms of their familiarity (high, middle, or low. Results demonstrate that the memory color effect occurs only in the high-familiarity condition, but not in the middle- and low-familiarity conditions. Furthermore, there is a positive correlation between the memory color effect and the actual number of domestic stores of the brand. In Experiment 2, we assessed the semantic association between logos and food/beverage names by using a semantic priming task to elucidate whether the memory color effect of logos relates to consumer brand cognition, and found that the semantic associations between logos and food/beverage names in the high-familiarity brands were stronger than those in the low-familiarity brands only when the logos were colored correctly, but not when they were appropriately or inappropriately colored, or achromatic.The current results provide behavioral evidence of the relationship between the familiarity of objects and the memory color effect and suggest that the memory color effect increases with the familiarity of objects, albeit not constantly.

Effect of the melting conditions on the properties of radiation color centers in lanthanum phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Karapetyan, G.O.; Rusan, V.V.; Yashchurzhinskaya, O.A.

1986-01-01

The authors investigate the spatial effects of ionizing radiation on the radiation processes in phosphate glasses to make a comparative estimate of the radiation yield from the radiation color centers (RCC) of different types. A study is made of their behavior under thermal decoloration. The results of a comparison of the integrated intensities of the ESR signal from trapping centers are given. The ESR spectrum of the glasses are presented--one differs slightly from the others. On the basis of the result of processing the ESR and optical spectra of gamma-irradiated lanthanum phosphate glasses synthesized under various conditions, the radiation yield of the RCC and the behavior of the intensity of their absorption under thermodecoloration are significantly affected by the conditions of synthesis of the glass.

Memory and neural networks on the basis of color centers in solids.

Science.gov (United States)

Winnacker, Albrecht; Osvet, Andres

2009-11-01

Optical data recording is one of the most widely used and efficient systems of memory in the non-living world. The application of color centers in this context offers not only systems of high speed in writing and read-out due to a high degree of parallelism in data handling but also a possibility to set up models of neural networks. In this way, systems with a high potential for image processing, pattern recognition and logical operations can be constructed. A limitation to storage density is given by the diffraction limit of optical data recording. It is shown that this limitation can at least in principle be overcome by the principle of spectral hole burning, which results in systems of storage capacities close to the human brain system.

Morphology and phase structures of CW laser-induced oxide layers on iron surface with evolving reflectivity and colors

Energy Technology Data Exchange (ETDEWEB)

Wu, Taotao, E-mail: wutaotao@nint.ac.cn; Wang, Lijun; Wei, Chenghua; Zhou, Menglian; He, Minbo; Wu, Lixiong

2016-11-30

Highlights: • Firstly, iron samples with different color features were obtained by continuous wave laser irradiation depending on progressive durations. The real-time reflectivity and temperature of samples were measured. The color and the reflectivity evolution were related. They were both caused by the forming oxide films. • Secondly, laser-induced oxidation process of iron was studied by microscope, X-ray diffraction and Raman spectrum. The first formed magnetite made the surface reflectivity decline rapidly and caused the “positive feedback” effect because of molecular absorption. The later formed hematite oscillated the reflectivity by interference effect. • Lastly, the laser-induced oxide films were thin, orientated and badly crystallized. The Wagner oxidation theory was incapable of describing the non-isothermal and early stage oxidation process. So we emphasized that a precise oxidation model depending on the experiment and the optical constants of the laser-induced oxides must be studied. - Abstract: Laser-induced oxidation will change the laser reflectivity and color features of metal surface. Both changes can be theoretically calculated based on the oxidation kinetics and the optical constants of oxides. For the purpose of calculation, the laser-induced oxidation process of pure polycrystalline iron was studied. Samples with various color features were obtained by continuous wave Nd:YAG fiber laser (1.06 μm) irradiation depending on progressive durations in the intensity of 1.90 W/cm{sup 2}. The real-time reflectivity and temperature were measured with integral sphere and thermocouples. The irradiated surface morphology and phase structures were characterized by microscope, X-ray diffraction and Raman spectrum. It was found that the first formed magnetite made the surface reflectivity decline rapidly and caused the “positive feedback” effect because of molecular absorption. The later formed hematite oscillated the reflectivity by

Purple sweet potato color attenuates domoic acid-induced cognitive deficits by promoting estrogen receptor-α-mediated mitochondrial biogenesis signaling in mice.

Science.gov (United States)

Lu, Jun; Wu, Dong-Mei; Zheng, Yuan-Lin; Hu, Bin; Cheng, Wei; Zhang, Zi-Feng

2012-02-01

Recent findings suggest that endoplasmic reticulum stress may be involved in the pathogenesis of domoic acid-induced neurodegeneration. Purple sweet potato color, a class of naturally occurring anthocyanins, has beneficial health and biological effects. Recent studies have also shown that anthocyanins have estrogenic activity and can enhance estrogen receptor-α expression. In this study, we evaluated the effect of purple sweet potato color on cognitive deficits induced by hippocampal mitochondrial dysfunction in domoic acid-treated mice and explored the potential mechanisms underlying this effect. Our results showed that the oral administration of purple sweet potato color to domoic acid-treated mice significantly improved their behavioral performance in a step-through passive avoidance task and a Morris water maze task. These improvements were mediated, at least in part, by a stimulation of estrogen receptor-α-mediated mitochondrial biogenesis signaling and by decreases in the expression of p47phox and gp91phox. Decreases in reactive oxygen species and protein carbonylation were also observed, along with a blockade of the endoplasmic reticulum stress pathway. Furthermore, purple sweet potato color significantly suppressed endoplasmic reticulum stress-induced apoptosis, which prevented neuron loss and restored the expression of memory-related proteins. However, knockdown of estrogen receptor-α using short hairpin RNA only partially blocked the neuroprotective effects of purple sweet potato color in the hippocampus of mice cotreated with purple sweet potato color and domoic acid, indicating that purple sweet potato color acts through multiple pathways. These results suggest that purple sweet potato color could be a possible candidate for the prevention and treatment of cognitive deficits in excitotoxic and other brain disorders. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Hybridizing Differential Evolution with a Genetic Algorithm for Color Image Segmentation

Directory of Open Access Journals (Sweden)

R. V. V. Krishna

2016-10-01

Full Text Available This paper proposes a hybrid of differential evolution and genetic algorithms to solve the color image segmentation problem. Clustering based color image segmentation algorithms segment an image by clustering the features of color and texture, thereby obtaining accurate prototype cluster centers. In the proposed algorithm, the color features are obtained using the homogeneity model. A new texture feature named Power Law Descriptor (PLD which is a modification of Weber Local Descriptor (WLD is proposed and further used as a texture feature for clustering. Genetic algorithms are competent in handling binary variables, while differential evolution on the other hand is more efficient in handling real parameters. The obtained texture feature is binary in nature and the color feature is a real value, which suits very well the hybrid cluster center optimization problem in image segmentation. Thus in the proposed algorithm, the optimum texture feature centers are evolved using genetic algorithms, whereas the optimum color feature centers are evolved using differential evolution.

Radiation-induced coloration of nitro blue tetrazolium gel dosimeter for low dose applications

International Nuclear Information System (INIS)

Abdel-Fattah, A.A.; Beshir, W.B.; Hassan, H.M.; Soliman, Y.S.

2017-01-01

A radiochromic sensor of nitro blue tetrazolium (NBT) in gelatin was evaluated as a new gel dosimeter for radiation applications. The NBT gel has the advantage of visual color change from faint yellow to violet at low absorbed doses (10–1000 Gy). This color change appears as a result of the reduction of NBT to colored formazan then to diformazan species with further increase of absorbed doses. Responses of the gel at different NBT concentrations were analyzed at the absorption maximum centered at 527 nm. An increase of NBT concentrations in the gel enhances the radiation dose sensitivity. Energy dependent study implies the tissue equivalency of the gel in the energy range of 0.15–20 MeV. Dependence of the gel response on irradiation temperature, and color stability before and after irradiation were also studied. The combined uncertainty associated with the dose monitoring (10–1000 Gy) is 6.26% (2σ). Thus, the NBT gel shows its suitability for food irradiation, insect population control, and some food irradiation applications. - Highlights: • Preparation of nitro blue tetrazolium (NBT) gel for the dose range of 10–1000 Gy. • The sensitivity of it increases with increasing NBT concentrations. • The response of irradiated dosimeter is stable after 5 h from irradiation. • The prepared gel dosimeter is a tissue equivalent. • Its combined uncertainty is equal to 6.26% for 10–1000 Gy dose level.

Zero-phonon lines and electron–phonon interaction characteristics of near-surface layer radiation color centers in lithium fluoride

Energy Technology Data Exchange (ETDEWEB)

Voitovich, A.P., E-mail: voitovich@ifanbel.bas-net.by [Institute of Physics, National Academy of Sciences of Belarus, 68 Nezavisimosti Avenue, 220072 Minsk (Belarus); Kalinov, V.S. [Institute of Physics, National Academy of Sciences of Belarus, 68 Nezavisimosti Avenue, 220072 Minsk (Belarus); Mudryi, A.V. [Scientific-Practical Materials Research Center, National Academy of Sciences of Belarus, 19 Brovka Street, 220072 Minsk (Belarus); Pavlovskii, V.N.; Runets, L.P.; Svitsiankou, I.E. [Institute of Physics, National Academy of Sciences of Belarus, 68 Nezavisimosti Avenue, 220072 Minsk (Belarus)

2016-04-15

Zero-phonon lines have been registered in photoluminescence spectra of near-surface layer radiation color centers in lithium fluoride nanocrystals. They have been assigned to transitions of the definite types centers. The frequencies of phonons participating in the transitions of the different type centers located both in the near-surface layer and in the crystal bulk have been measured and compared. The Huang-Rhys parameters for the transitions of these centers have been determined. It has been found that the Huang-Rhys parameters for the studied transitions in the near-surface layer centers of the certain composition are less than for those in the crystal bulk centers of the same composition. This feature is connected with the difference of the electron density distribution in defects. Temperature dependences of the zero-phonon lines widths and shifts have been measured. It has been determined that both widths and shifts grow faster with the increase of a temperature for the defects transitions with the lesser Huang-Rhys parameters. Phonons lifetimes are estimated from the experimental data.

Zero-phonon lines and electron–phonon interaction characteristics of near-surface layer radiation color centers in lithium fluoride

International Nuclear Information System (INIS)

Voitovich, A.P.; Kalinov, V.S.; Mudryi, A.V.; Pavlovskii, V.N.; Runets, L.P.; Svitsiankou, I.E.

2016-01-01

Zero-phonon lines have been registered in photoluminescence spectra of near-surface layer radiation color centers in lithium fluoride nanocrystals. They have been assigned to transitions of the definite types centers. The frequencies of phonons participating in the transitions of the different type centers located both in the near-surface layer and in the crystal bulk have been measured and compared. The Huang-Rhys parameters for the transitions of these centers have been determined. It has been found that the Huang-Rhys parameters for the studied transitions in the near-surface layer centers of the certain composition are less than for those in the crystal bulk centers of the same composition. This feature is connected with the difference of the electron density distribution in defects. Temperature dependences of the zero-phonon lines widths and shifts have been measured. It has been determined that both widths and shifts grow faster with the increase of a temperature for the defects transitions with the lesser Huang-Rhys parameters. Phonons lifetimes are estimated from the experimental data.

Learning color receptive fields and color differential structure

NARCIS (Netherlands)

ter Haar Romenij, B.M.

2016-01-01

In this paper we study the role of brain plasticity, and investigate the emergence and self-emergence of receptive fields from scalar and color natural images by principal component analysis of image patches. We describe the classical experiment on localized PCA on center-surround weighted patches

Contribution of a luminance-dependent S-cone mechanism to non-assimilative color spreading in the watercolor configuration

Directory of Open Access Journals (Sweden)

Eiji eKimura

2014-12-01

Full Text Available In the watercolor configuration composed of wavy double contours, both assimilative and non-assimilative color spreading have been demonstrated depending on the luminance conditions of the inner and outer contours (IC and OC, respectively. This study investigated how the induced color in the watercolor configuration was modulated by combinations of the IC and the OC color, particularly addressing non-assimilative color spreading. In two experiments, the IC color was fixed to a certain color and combined with various colors selected from a hue circle centered at the background white color. Color spreading was quantified with a chromatic cancellation technique. Results showed that both the magnitude and the apparent hue of the color spreading were largely changed with the luminance condition. When the IC contrast (Weber contrast of the IC to the background luminance was smaller in size than the OC contrast (higher IC luminance condition, the color spreading was assimilative. When the luminance condition was reversed and the IC contrast was greater than the OC contrast (lower IC luminance condition, the color spreading was non-assimilative and yellowish. When the color spreading was analyzed in terms of cone-opponent excitations, the results were consistent with the interpretation that the color spreading is explainable by a combination of chromatic diffusion from the IC and chromatically opponent induction from the OC. The color spreading in the higher IC luminance condition mainly reflected the chromatic diffusion by both (L–M and S cone-opponent mechanisms. The non-assimilative color spreading in the lower IC luminance condition mostly reflected S-cone mediated opponent induction and the contribution of -S inducing mechanisms was differentially large. These findings provided several constraints on possible visual mechanisms underlying the watercolor effect.

Contribution of a luminance-dependent S-cone mechanism to non-assimilative color spreading in the watercolor configuration.

Science.gov (United States)

Kimura, Eiji; Kuroki, Mikako

2014-01-01

In the watercolor configuration composed of wavy double contours, both assimilative and non-assimilative color spreading have been demonstrated depending on the luminance conditions of the inner and outer contours (IC and OC, respectively). This study investigated how the induced color in the watercolor configuration was modulated by combinations of the IC and the OC color, particularly addressing non-assimilative color spreading. In two experiments, the IC color was fixed to a certain color and combined with various colors selected from a hue circle centered at the background white color. Color spreading was quantified with a chromatic cancelation technique. Results showed that both the magnitude and the apparent hue of the color spreading were largely changed with the luminance condition. When the IC contrast (Weber contrast of the IC to the background luminance) was smaller in size than the OC contrast (higher IC luminance condition), the color spreading was assimilative. When the luminance condition was reversed and the IC contrast was greater than the OC contrast (lower IC luminance condition), the color spreading was non-assimilative and yellowish. When the color spreading was analyzed in terms of cone-opponent excitations, the results were consistent with the interpretation that the color spreading is explainable by a combination of chromatic diffusion from the IC and chromatically opponent induction from the OC. The color spreading in the higher IC luminance condition mainly reflected the chromatic diffusion by both (L-M) and S cone-opponent mechanisms. The non-assimilative color spreading in the lower IC luminance condition mostly reflected S-cone mediated opponent induction and the contribution of -S inducing mechanisms was differentially large. These findings provided several constraints on possible visual mechanisms underlying the watercolor effect.

Directional effect on coloration in LiF crystal by H{sup +} and H{sub 2}{sup +} ion bombardment

Energy Technology Data Exchange (ETDEWEB)

Mingle, Gan; Naramoto, Hiroshi; Aoki, Yasushi; Yamamoto, Shunya; Jianer, Zeng; Takeshita, Hidefumi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1997-03-01

In the present paper, the first results are reported about the coloration in LiF crystals induced by bombardments of single hydrogen ions (H{sup +}) and molecular hydrogen ions (H{sub 2}{sup +}) with the same velocity under the <100> aligned and random conditions. For the single hydrogen ion irradiation, the coloration is rather simple. The F-type color center absorption under the <100> aligned condition becomes larger than that under the random condition with the dose increase because of larger fraction of electronic energy loss under channeling condition. On the contrary, the coloration for the molecular ions does not show big channeling effect. In the low dose region some difference can be seen but the difference of coloration is not observed any more with the dose increase. The pronounced coloration for molecular ions under the channeling condition is observed in comparison with that for single ions. (author)

A new method for skin color enhancement

Science.gov (United States)

Zeng, Huanzhao; Luo, Ronnier

2012-01-01

Skin tone is the most important color category in memory colors. Reproducing it pleasingly is an important factor in photographic color reproduction. Moving skin colors toward their preferred skin color center improves the skin color preference on photographic color reproduction. Two key factors to successfully enhance skin colors are: a method to detect original skin colors effectively even if they are shifted far away from the regular skin color region, and a method to morph skin colors toward a preferred skin color region properly without introducing artifacts. A method for skin color enhancement presented by the authors in the same conference last year applies a static skin color model for skin color detection, which may miss to detect skin colors that are far away from regular skin tones. In this paper, a new method using the combination of face detection and statistical skin color modeling is proposed to effectively detect skin pixels and to enhance skin colors more effectively.

Memory Color Effect Induced by Familiarity of Brand Logos

OpenAIRE

Kimura, Atsushi; Wada, Yuji; Masuda, Tomohiro; Goto, Sho-ichi; Tsuzuki, Daisuke; Hibino, Haruo; Cai, Dongsheng; Dan, Ippeita

2013-01-01

Background When people are asked to adjust the color of familiar objects such as fruits until they appear achromatic, the subjective gray points of the objects are shifted away from the physical gray points in a direction opposite to the memory color (memory color effect). It is still unclear whether the discrepancy between memorized and actual colors of objects is dependent on the familiarity of the objects. Here, we conducted two experiments in order to examine the relationship between the ...

Color in present culture of European architecture

Science.gov (United States)

Schindler, Verena M.

2002-06-01

The influential architect Le Corbusier (1887 - 1965) was also involved in the adventure of contemporary painting, and color occupied half of his day, during twenty years, as he revealed in a study entitled 'Architectural Polychromy' written in the early thirties and recently published in 1997. In the present, contemporary architects in Central Europe are dealing with color in quite a different and exceptional way: most of them engage the artist to collaborate with them in their architectural projects. If painting is concerned with the interaction of color in the two-dimensional plane, architecture is deeply dependent on light and space, and deals entirely with the three- dimensional environment and its human perception. In the 1990s, the way architects and artists employed color in architecture was so striking that color offered a key to larger discussions and opened up an interesting aspect of architectural practice. It must be remembered that recent housing projects, such as the housing estate Pilotengasse in Vienna, Gigon & Guyer's Broelberg in Kilchberg (with Harald F. Muller), next to Zurich, and their Sport Center in Davos (with Adrian Schiess), Jean Nouvel's Cultural and Congress Center in Lucerne, or Sauerbruch & Hutton's Photonic Center and their GSW office building in Berlin have all been contributing to free color from its unconscious and dormant role. These works all impart qualities to color in architecture that were hitherto reserved to other materials and fields: they define the aspects of the interaction of visual and physical space, of materialization of volumes, and of the expression of wealth and luxury.

Real color captures attention and overrides spatial cues in grapheme-color synesthetes but not in controls.

Science.gov (United States)

van Leeuwen, Tessa M; Hagoort, Peter; Händel, Barbara F

2013-08-01

Grapheme-color synesthetes perceive color when reading letters or digits. We investigated oscillatory brain signals of synesthetes vs. controls using magnetoencephalography. Brain oscillations specifically in the alpha band (∼10Hz) have two interesting features: alpha has been linked to inhibitory processes and can act as a marker for attention. The possible role of reduced inhibition as an underlying cause of synesthesia, as well as the precise role of attention in synesthesia is widely discussed. To assess alpha power effects due to synesthesia, synesthetes as well as matched controls viewed synesthesia-inducing graphemes, colored control graphemes, and non-colored control graphemes while brain activity was recorded. Subjects had to report a color change at the end of each trial which allowed us to assess the strength of synesthesia in each synesthete. Since color (synesthetic or real) might allocate attention we also included an attentional cue in our paradigm which could direct covert attention. In controls the attentional cue always caused a lateralization of alpha power with a contralateral decrease and ipsilateral alpha increase over occipital sensors. In synesthetes, however, the influence of the cue was overruled by color: independent of the attentional cue, alpha power decreased contralateral to the color (synesthetic or real). This indicates that in synesthetes color guides attention. This was confirmed by reaction time effects due to color, i.e. faster RTs for the color side independent of the cue. Finally, the stronger the observed color dependent alpha lateralization, the stronger was the manifestation of synesthesia as measured by congruency effects of synesthetic colors on RTs. Behavioral and imaging results indicate that color induces a location-specific, automatic shift of attention towards color in synesthetes but not in controls. We hypothesize that this mechanism can facilitate coupling of grapheme and color during the development of

2014 - Color & Infrared - Northeastern Vermont (0.5m)

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) This metadata record describes the acquisition and production of natural color and color infrared digital ground orthoimagery covering a portion...

Probing color-singlet exchange at D0

International Nuclear Information System (INIS)

Abbott, B.; Abolins, M.; Acharya, B.S.

1997-07-01

We present latest preliminary results on hard color-singlet exchange in proton-antiproton collisions. The fraction of dijet events produced via color-singlet exchange is measured as a function of jet transverse energy, dijet pseudorapidity separation, and proton-antiproton center-of-mass energy. These results are qualitatively consistent with a color-singlet fraction that increases with increasing quark-initiated processes

Photoluminescence excitation spectroscopy of SiV- and GeV- color center in diamond

Science.gov (United States)

Häußler, Stefan; Thiering, Gergő; Dietrich, Andreas; Waasem, Niklas; Teraji, Tokuyuki; Isoya, Junichi; Iwasaki, Takayuki; Hatano, Mutsuko; Jelezko, Fedor; Gali, Adam; Kubanek, Alexander

2017-06-01

Color centers in diamond are important quantum emitters for a broad range of applications ranging from quantum sensing to quantum optics. Understanding the internal energy level structure is of fundamental importance for future applications. We experimentally investigate the level structure of an ensemble of few negatively charged silicon-vacancy (SiV-) and germanium-vacancy (GeV-) centers in bulk diamond at room temperature by photoluminescence (PL) and excitation (PLE) spectroscopy over a broad wavelength range from 460 to 650 {nm} and perform power-dependent saturation measurements. For SiV- our experimental results confirm the presence of a higher energy transition at ˜ 2.31 {eV}. By comparison with detailed theoretical simulations of the imaginary dielectric function we interpret the transition as a dipole-allowed transition from {}2{E}g-state to {}2{A}2u-state where the corresponding a 2u -level lies deeply inside the diamond valence band. Therefore, the transition is broadened by the diamond band. At higher excitation power of 10 {mW} we indicate signs of a parity-conserving transition at ˜ 2.03 {eV} supported by saturation measurements. For GeV- we demonstrate that the PLE spectrum is in good agreement with the mirror image of the PL spectrum of the zero-phonon line. Experimentally we do not observe a higher lying energy level up to a transition wavelength of 460 {nm}. The observed PL spectra are identical, independent of excitation wavelength, suggesting a rapid decay to {}2{E}u excited state and followed by optical transition to {}2{E}g ground state. Our investigations convey important insights for future quantum optics and quantum sensing experiments based on SiV--center and GeV--center in diamond.

Graphemes Sharing Phonetic Features Tend to Induce Similar Synesthetic Colors

OpenAIRE

Kang, Mi-Jeong; Kim, Yeseul; Shin, Ji-Young; Kim, Chai-Youn

2017-01-01

Individuals with grapheme-color synesthesia experience idiosyncratic colors when viewing achromatic letters or digits. Despite large individual differences in grapheme-color association, synesthetes tend to associate graphemes sharing a perceptual feature with similar synesthetic colors. Sound has been suggested as one such feature. In the present study, we investigated whether graphemes of which representative phonemes have similar phonetic features tend to be associated with analogous synes...

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.

2016 - Color & Infrared - Rutland and Windsor (0.15m)

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) This metadata record describes the acquisition and production of natural color and color infrared digital ground orthoimagery covering a portion...

2016 - Color & Infrared - Rutland and Windsor (0.3m)

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) This metadata record describes the acquisition and production of natural color and color infrared digital ground orthoimagery covering a portion...

FNTD radiation dosimetry system enhanced with dual-color wide-field imaging

International Nuclear Information System (INIS)

Akselrod, M.S.; Fomenko, V.V.; Bartz, J.A.; Ding, F.

2014-01-01

At high neutron and photon doses Fluorescent Nuclear Track Detectors (FNTDs) require operation in analog mode and the measurement results depend on individual crystal color center concentration (coloration). We describe a new method for radiation dosimetry using FNTDs, which includes non-destructive, automatic sensitivity calibration for each individual FNTD. In the method presented, confocal laser scanning fluorescent imaging of FNTDs is combined with dual-color wide field imaging of the FNTD. The calibration is achieved by measuring the color center concentration in the detector through fluorescence imaging and reducing the effect of diffuse reflection on the lapped surface of the FNTD by imaging with infra-red (IR) light. The dual-color imaging of FNTDs is shown to provide a good estimation of the detector sensitivity at high doses of photons and neutrons, where conventional track counting is impeded by track overlap. - Highlights: • New method and optical imaging head was developed for FNTD used at high doses. • Dual-color wide-field imaging used for color center concentration measurement. • Green fluorescence corrected by diffuse reflection used for sensitivity correction. • FNTD dose measurements performed in analog processing mode

Luminescence of color centers in MgF{sub 2} crystals; Lyuminestsentsiya tsentrov okraski v kristallakh MgF{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Vakhidov, Sh A; Nuritdinov, I; Musaeva, M A [Inst. Yadernoj Fizili AN Uzbekistana, Tashkent (Uzbekistan)

1999-08-01

The photoluminescence characteristics of the proper radiation color centers of the MgF{sub 2} crystals are studied. The samples were irradiated by the {sup 60}Co source {gamma}-rays up to the dose 10{sup 7}Gy. The bands with the maxima in the area of 420, 460, 550 and 620 nm were identified, which are excited correspondingly in the bands with the maxima of 370, 320, 410 and 480 nm.

Tricolore. A flexible color scale for ternary compositions

DEFF Research Database (Denmark)

2018-01-01

tricolore is an R library providing a flexible color scale for the visualization of three-part/ternary compositions. Its main functionality is to color-code any ternary composition as a mixture of three primary colours and to draw a suitable color-key. tricolore flexibly adapts to different...... visualisation challenges via - discrete and continuous color support - support for unbalanced compositional data via centering - support for data with very narrow range via scaling - hue, chroma and lightness options...

Bubble-Induced Color Doppler Feedback for Histotripsy Tissue Fractionation.

Science.gov (United States)

Miller, Ryan M; Zhang, Xi; Maxwell, Adam D; Cain, Charles A; Xu, Zhen

2016-03-01

Histotripsy therapy produces cavitating bubble clouds to increasingly fractionate and eventually liquefy tissue using high-intensity ultrasound pulses. Following cavitation generated by each pulse, coherent motion of the cavitation residual nuclei can be detected using metrics formed from ultrasound color Doppler acquisitions. In this paper, three experiments were performed to investigate the characteristics of this motion as real-time feedback on histotripsy tissue fractionation. In the first experiment, bubble-induced color Doppler (BCD) and particle image velocimetry (PIV) analysis monitored the residual cavitation nuclei in the treatment region in an agarose tissue phantom treated with two-cycle histotripsy pulses at [Formula: see text] using a 500-kHz transducer. Both BCD and PIV results showed brief chaotic motion of the residual nuclei followed by coherent motion first moving away from the transducer and then rebounding back. Velocity measurements from both PIV and BCD agreed well, showing a monotonic increase in rebound time up to a saturation point for increased therapy dose. In a second experiment, a thin layer of red blood cells (RBC) was added to the phantom to allow quantification of the fractionation of the RBC layer to compare with BCD metrics. A strong linear correlation was observed between the fractionation level and the time to BCD peak rebound velocity over histotripsy treatment. Finally, the correlation between BCD feedback and histotripsy tissue fractionation was validated in ex vivo porcine liver evaluated histologically. BCD metrics showed strong linear correlation with fractionation progression, suggesting that BCD provides useful quantitative real-time feedback on histotripsy treatment progression.

Joint effects of emotion and color on memory.

Science.gov (United States)

Kuhbandner, Christof; Pekrun, Reinhard

2013-06-01

Numerous studies have shown that memory is enhanced for emotionally negative and positive information relative to neutral information. We examined whether emotion-induced memory enhancement is influenced by low-level perceptual attributes such as color. Because in everyday life red is often used as a warning signal, whereas green signals security, we hypothesized that red might enhance memory for negative information and green memory for positive information. To capture the signaling function of colors, we measured memory for words standing out from the context by color, and manipulated the color and emotional significance of the outstanding words. Making words outstanding by color strongly enhanced memory, replicating the well-known von Restorff effect. Furthermore, memory for colored words was further increased by emotional significance, replicating the memory-enhancing effect of emotion. Most intriguingly, the effects of emotion on memory additionally depended on color type. Red strongly increased memory for negative words, whereas green strongly increased memory for positive words. These findings provide the first evidence that emotion-induced memory enhancement is influenced by color and demonstrate that different colors can have different functions in human memory.

Electrolytic coloration of O22--doped NaCl crystals

International Nuclear Information System (INIS)

Qin Fang; Gu Hongen; Song Cuiying; Wang Na; Guo Meili; Wang Fen; Liu Jia

2007-01-01

O 2 2- -doped NaCl crystals are colored electrolytically by using a pointed cathode and a flat anode at various temperatures and voltages, which mainly benefit from appropriate coloration temperatures and voltages as well as anode structure of used electrolysis apparatus. Characteristic OH - , U, V 2 m , U A , V 2 , V 3 , O 2- -V a + complex, F, R 1 , R 2 and M absorption bands are observed in absorption spectra of the colored crystals. Production and conversion of color centers in electrolytic coloration is explained. Current-time curves for electrolytic colorations and their relationships with electrolytic colorations were given

Electron beam irradiation of gemstone for color enhancement

Science.gov (United States)

Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A'iasah; Ahmad, Shamshad; Jusoh, Mohd Suhaimi

2012-09-01

Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.

Electron beam irradiation of gemstone for color enhancement

Energy Technology Data Exchange (ETDEWEB)

Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A' iasah; Ahmad, Shamshad; Jusoh, Mohd Suhaimi [Malaysian Nuclear Agency, Bangi, Selangor (Malaysia); School of Chemicals and Material Engineering, NUST Islamabad (Pakistan); Malaysian Nuclear Agency, Bangi, Selangor (Malaysia)

2012-09-26

Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.

Electron beam irradiation of gemstone for color enhancement

International Nuclear Information System (INIS)

Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A'iasah; Ahmad, Shamshad; Jusoh, Mohd Suhaimi

2012-01-01

Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.

Tungstate-induced color-pattern modifications of butterfly wings are independent of stress response and ecdysteroid effect.

Science.gov (United States)

Otaki, Joji M; Ogasawara, Tsuyoshi; Yamamoto, Haruhiko

2005-06-01

Systemic injections of sodium tungstate, a protein-tyrosine phosphatase (PTPase) inhibitor, to pupae immediately after pupation have been shown to efficiently produce characteristic color-pattern modifications on the wings of many species of butterflies. Here we demonstrated that the tungstate-induced modification pattern was entirely different from other chemically-induced ones in a species of nymphalid butterfly Junonia (Precis) orithya. In this species, the systemic injections of tungstate produced characteristic expansion of black area and shrinkage of white area together with the move of parafocal elements toward the wing base. Overall, pattern boundaries became obscure. In contrast, an entirely different modification pattern, overall darkening of wings, was observed by the injections of stress-inducing chemicals, thapsigargin, ionomycin, or geldanamycin, to pupae under the rearing conditions for the adult summer form. On the ventral wings, this darkening was due to an increase of the proportion of peppered dark scales, which was reminiscent of the natural fall form of this species. Under the same rearing conditions, the injections of ecdysteroid, which is a well-known hormone being responsible for the seasonal polyphenism of nymphalid butterflies, yielded overall expansion of orange area especially around eyespots. Taken together, we conclude that the tungstate-induced modifications are clearly distinguishable from those of stress response and ecdysteroid effect. This conclusion then suggests that the putative PTPase signaling pathway that is sensitive to tungstate uniquely contributes to the wing-wide color-pattern development in butterflies.

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.

The colors of the alphabet: naturally-biased associations between shape and color.

Science.gov (United States)

Spector, Ferrinne; Maurer, Daphne

2011-04-01

Many letters of the alphabet are consistently mapped to specific colors in English-speaking adults, both in the general population and in individuals with grapheme-color synaesthesia who perceive letters in color. Here, across six experiments, we tested the ubiquity of the color/letter associations with typically developing toddlers, literate children, and adults. We found that pre-literate children associate O with white and X with black and discovered that they also associate I and ameboid nonsense shapes with white; Z and jagged nonsense shapes with black; and C with yellow; but do not make a number of other associations (B blue; Y yellow; A red; G green) seen in literate children and adults. The toddlers' mappings were based on the shape and not the sound of the letter. The results suggest that sensory cortical organization initially binds specific colors to some specific shapes and that learning to read can induce additional associations, likely through the influence of higher order networks as letters take on meaning.

Myoglobin chemistry and meat color.

Science.gov (United States)

Suman, Surendranath P; Joseph, Poulson

2013-01-01

Consumers rely heavily on fresh meat color as an indicator of wholesomeness at the point of sale, whereas cooked color is exploited as an indicator of doneness at the point of consumption. Deviations from the bright cherry-red color of fresh meat lead to product rejection and revenue loss. Myoglobin is the sarcoplasmic heme protein primarily responsible for the meat color, and the chemistry of myoglobin is species specific. The mechanistic interactions between myoglobin and multiple extrinsic and intrinsic factors govern the color of raw as well as cooked meats. The objective of this review is to provide an overview of the current research in meat color and how the findings are applied in the meat industry. Characterizing the fundamental basis of myoglobin's interactions with biomolecules in postmortem skeletal muscles is necessary to interpret the chemistry of meat color phenomena and to engineer innovative processing strategies to minimize meat discoloration-induced revenue loss to the agricultural economy.

Distilling two-center-interference information during tunneling of aligned molecules with orthogonally polarized two-color laser fields

Science.gov (United States)

Gao, F.; Chen, Y. J.; Xin, G. G.; Liu, J.; Fu, L. B.

2017-12-01

When electrons tunnel through a barrier formed by the strong laser field and the two-center potential of a diatomic molecule, a double-slit-like interference can occur. However, this interference effect can not be probed directly right now, as it is strongly coupled with other dynamical processes during tunneling. Here, we show numerically and analytically that orthogonally polarized two-color (OTC) laser fields are capable of resolving the interference effect in tunneling, while leaving clear footprints of this effect in photoelectron momentum distributions. Moreover, this effect can be manipulated by changing the relative field strength of OTC fields.

Color coherence in W + jet events

International Nuclear Information System (INIS)

Abbott, B.

1997-11-01

We report on preliminary studies of color coherence effects in p anti p collisions, based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron collider, at a center of mass energy √s = 1.8 TeV. Color interference effects are studied by examining particle distribution patterns in W + Jet events. The data are compared to Monte Carlo simulations with different color coherence implementations and to a recent analytic Modified-Leading-Log perturbative calculation based on the Local Parton-Hadron Duality hypothesis. Soft particle radiation is enhanced in the event plane relative to the transverse plane, in agreement with calculations in which the effects of color coherence are fully included

Plate Full of Color

Centers for Disease Control (CDC) Podcasts

2008-08-04

The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Plate Full of Color teaches the value of eating a variety of colorful and healthy foods.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

Ultrathin Nanocrystalline Diamond Films with Silicon Vacancy Color Centers via Seeding by 2 nm Detonation Nanodiamonds.

Science.gov (United States)

Stehlik, Stepan; Varga, Marian; Stenclova, Pavla; Ondic, Lukas; Ledinsky, Martin; Pangrac, Jiri; Vanek, Ondrej; Lipov, Jan; Kromka, Alexander; Rezek, Bohuslav

2017-11-08

Color centers in diamonds have shown excellent potential for applications in quantum information processing, photonics, and biology. Here we report chemical vapor deposition (CVD) growth of nanocrystalline diamond (NCD) films as thin as 5-6 nm with photoluminescence (PL) from silicon-vacancy (SiV) centers at 739 nm. Instead of conventional 4-6 nm detonation nanodiamonds (DNDs), we prepared and employed hydrogenated 2 nm DNDs (zeta potential = +36 mV) to form extremely dense (∼1.3 × 10 13 cm -2 ), thin (2 ± 1 nm), and smooth (RMS roughness < 0.8 nm) nucleation layers on an Si/SiO x substrate, which enabled the CVD growth of such ultrathin NCD films in two different and complementary microwave (MW) CVD systems: (i) focused MW plasma with an ellipsoidal cavity resonator and (ii) pulsed MW plasma with a linear antenna arrangement. Analytical ultracentrifuge, infrared and Raman spectroscopies, atomic force microscopy, and scanning electron microscopy are used for detailed characterization of the 2 nm H-DNDs and the nucleation layer as well as the ultrathin NCD films. We also demonstrate on/off switching of the SiV center PL in the NCD films thinner than 10 nm, which is achieved by changing their surface chemistry.

Color variation induced by abutments in the superior anterior maxilla: an in vitro study in the pig gingiva.

Science.gov (United States)

Atash, Ramin; Boularbah, Mohamed-Reda; Sibel, Cetik

2016-12-01

The aim of this work is to evaluate different types of materials used for making implant abutments, by means of an in vitro study and a review of the literature, in order to identify the indications for a better choice of an implant-supported restoration in the anterior section. 5 implant abutments were tested in a random order in the superior anterior maxilla of pig gingiva (n = 8): titanium dioxide (Nobel Biocare); zirconium dioxide, Standard BO shade (Nobel Biocare, Kloten, Switzerland); zirconium dioxide, Light BI shade (Nobel Biocare); zirconium dioxide, Intense A 3.5 shade (Nobel Biocare); and aluminium oxide. Each abutment was tested for 2 mm and 3 mm thickness. To determine color variation, VITA Easyshade Advance spectrophotometer (Vita Zahnfabrik, Bad Sackingen, Germany) was used. Results showed that the color variation induced by the abutment would be affected by the abutment material and gingival thickness, when the gingival thickness is 2 mm. All materials except zirconium dioxide (Standard shade) caused a visible change of color. Then, as the thickness of the gingiva increased to 3 mm, the color variation was attenuated in a significant manner and became invisible for all types of abutments, except those made of aluminium oxide. Zirconium dioxide is the material causing the lowest color variation at 2 mm and at 3 mm, whereas aluminium oxide causes the highest color variation no matter the thickness.

Possible influences on color constancy by motion of color targets and by attention-controlled gaze.

Science.gov (United States)

Wan, Lifang; Shinomori, Keizo

2018-04-01

We investigated the influence of motion on color constancy using a chromatic stimulus presented in various conditions (static, motion, and rotation). Attention to the stimulus and background was also controlled in different gaze modes, constant fixation of the stimulus, and random viewing of the stimulus. Color constancy was examined in six young observers using a haploscopic view of a computer monitor. The target and background were illuminated in simulation by red, green, blue, and yellow, shifted from daylight (D65) by specific color differences along L - M or S - (L + M) axes on the equiluminance plane. The standard pattern (under D65) and test pattern (under the color illuminant) of a 5-deg square were presented side by side, consisting of 1.2-deg square targets with one of 12 colors at each center, surrounded by 230 background ellipses consisting of eight other colors. The central color targets in both patterns flipped between top and bottom locations at the rate of 3 deg/s in the motion condition. The results indicated an average reduction of color constancy over the 12 test colors by motion. The random viewing parameter indicated better color constancy by more attention to the background, although the difference was not significant. Color constancy of the four color illuminations was better to worse in green, red, yellow, and blue, respectively. The reduction of color constancy by motion could be explained by less contribution of the illumination estimation effect on color constancy. In the motion with constant fixation condition, the retina strongly adapted to the mean chromaticity of the background. However, motion resulted in less attention to the color of the background, causing a weaker effect of the illumination estimation. Conversely, in the static state with a random viewing condition, more attention to the background colors caused a stronger illumination estimation effect, and color constancy was improved overall.

Color Gradient in the King Type Globular Cluster NGC 7089

Directory of Open Access Journals (Sweden)

Young-Jong Sohn

1999-12-01

Full Text Available We use BV CCD images to investigate the reality of the color gradient within a King type globular cluster NGC 7089. Surface photometry shows that there is a strong radial color gradient in the central region of the cluster in the sense of bluer center with the amplitude of -0.39 +/- 0.07 mag/arcsec2 in (B - V. In the outer region of the cluster, however, the radial color gradient shows a reverse case, i.e., redder toward the center. (B - V color profile which was derived from resolved stars in VGC 7089 field also shows a significant color gradient in the central region of the clusters, indicating that lights from the combination of red giant stars and blue horizontal branch stars cause the radial color gradient. Color gradient of the outer region of NGC 7089 may be due to the unresolved background of the cluster. Similar color gradients in the central area of clusters have been previously observed exserved exclusively in highly concentrated systems classified as post core collapse clusters. We caution, however, to confirm the reality of the color gradient from resolved stars, we need more accurate imaging data of the cluster with exceptional seeing condition because the effect of completeness correlates with local density of stars.

Color ornaments and territory position in king penguins.

Science.gov (United States)

Keddar, Ismaël; Jouventin, Pierre; Dobson, F Stephen

2015-10-01

King penguins exhibit mutual color ornamentation of feathers and beak color. They breed in dense colonies and produce a single chick every 2 years. Thus, males and females must choose partners carefully to be reproductively successful, and auricular patches of males and UV coloration of beak spots have been shown to influence mate choice. Position in the breeding colony is also important to reproductive success, with pairs on the edge of the colony less successful than those in the center. We studied the mutual ornaments, individual condition, and position of pairs in their breeding colony. Males were significantly larger than females in size, body mass, and auricular patch size. Within pairs, auricular patch size of males and females were significantly correlated, and male auricular patch size and body mass were significantly associated, suggesting a link between this ornament and male body condition. Moving from the edge to the center of the colony, pairs had larger yellow-orange auricular patches, indicating a link between this ornament and settlement in higher quality territories in the center of the colony. Pairs were also less brightly brown colored on the breast and less saturated in UV color of the beak spot. Since we observed pairs that were settling for egg laying, location in the colony may have reflected aspects of pair condition, rather than later jockeying for positioning using ornaments as signals of behavioral dominance. Copyright © 2015 Elsevier B.V. All rights reserved.

The role of transparency cues in afterimage color perception.

Science.gov (United States)

On, Zhi Xiang; van Boxtel, Jeroen J A

2017-08-23

Recent evidence has shown that afterimage perception and completion are amenable to contextual information. It has previously been shown that placing an outline around part of the afterimage can induce colors in areas that were uncolored. A thorough explanation of this effect is lacking, although this color completion was thought to be due to a diffusion-like filling-in of the uncolored patch with colors of the surrounding areas. Here, we show that an important step in visual completion is the decomposition of the visual scene into different depth layers, i.e. scission, which, we show, is guided by transparency cues in the van Lier et al. In three experiments, we show that when decomposition is prevented, color completion does not occur. We also show that this decomposition can induce color completion in real images. These results demonstrate that transparency information plays an important role in determining visual color completion processes.

Assimilative and non-assimilative color spreading in the watercolor configuration

Directory of Open Access Journals (Sweden)

Eiji eKimura

2014-09-01

Full Text Available A colored line flanking a darker contour will appear to spread its color onto an area enclosed by the line (watercolor effect. The watercolor effect has been characterized as an assimilative effect, but non-assimilative color spreading has also been demonstrated in the same spatial configuration; e.g., when a black inner contour (IC is paired with a blue outer contour (OC, yellow color spreading can be observed. To elucidate visual mechanisms underlying these different color spreading effects, this study investigated the effects of luminance ratio between the double contours on the induced color by systematically manipulating the IC and OC luminances (Experiment 1 as well as the background luminance (Experiment 2. The results showed that the luminance conditions suitable for assimilative and non-assimilative color spreading were nearly opposite. When the Weber contrast of the IC to the background luminances (IC contrast was smaller than that of the OC (OC contrast, the induced color became similar to the IC color (assimilative spreading. In contrast, when the OC contrast was smaller than or equal to the IC contrast, the induced color became yellow (non-assimilative spreading. Extending these findings, Experiment 3 showed that bilateral color spreading, e.g., assimilative spreading on one side and non-assimilative spreading on the other side, can also be observed in the watercolor configuration. These results suggest that the assimilative and non-assimilative spreading were mediated by different visual mechanisms. The properties of the assimilative spreading are consistent with the model proposed to account for neon color spreading [Grossberg, S. & Mingolla, E. (1985 Percept. Psychophys., 38, 141-171] and extended for the watercolor effect [Pinna, B., & Grossberg, S. (2005 J. Opt. Soc. Am. A, 22, 2207-2221]. However, the present results suggest that additional mechanisms are needed to account for the non-assimilative color spreading.

Assimilative and non-assimilative color spreading in the watercolor configuration.

Science.gov (United States)

Kimura, Eiji; Kuroki, Mikako

2014-01-01

A colored line flanking a darker contour will appear to spread its color onto an area enclosed by the line (watercolor effect). The watercolor effect has been characterized as an assimilative effect, but non-assimilative color spreading has also been demonstrated in the same spatial configuration; e.g., when a black inner contour (IC) is paired with a blue outer contour (OC), yellow color spreading can be observed. To elucidate visual mechanisms underlying these different color spreading effects, this study investigated the effects of luminance ratio between the double contours on the induced color by systematically manipulating the IC and the OC luminance (Experiment 1) as well as the background luminance (Experiment 2). The results showed that the luminance conditions suitable for assimilative and non-assimilative color spreading were nearly opposite. When the Weber contrast of the IC to the background luminance (IC contrast) was smaller in size than that of the OC (OC contrast), the induced color became similar to the IC color (assimilative spreading). In contrast, when the OC contrast was smaller than or equal to the IC contrast, the induced color became yellow (non-assimilative spreading). Extending these findings, Experiment 3 showed that bilateral color spreading, i.e., assimilative spreading on one side and non-assimilative spreading on the other side, can also be observed in the watercolor configuration. These results suggest that the assimilative and the non-assimilative spreading were mediated by different visual mechanisms. The properties of the assimilative spreading are consistent with the model proposed to account for neon color spreading (Grossberg and Mingolla, 1985) and extended for the watercolor effect (Pinna and Grossberg, 2005). However, the present results suggest that additional mechanisms are needed to account for the non-assimilative color spreading.

VT Data - VTORTHO Color Imagery (0.15m) 2017, Addison County

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) This metadata record describes the acquisition and production of 15 centimeter ground sample distance (GSD) natural color and color infrared...

Study of Tl0(1) and In0(1) defects in alkaline halides: prototype of a color center as active laser medium

International Nuclear Information System (INIS)

Vieira Junior, N.D.

1986-01-01

The optical properties of the Tl 0 (1) and In 0 (1) centers in Kcl crystals in cation sites of the crystal lattice, perturbed by an adjacent anion vacancy. Emphasis is given to the lowest energy levels. Using a tagging optical absorption technique, the absorption bands were identified. The laser action of Tl 0 (1) center in KCl by pumping with Nd: YAG laser in the lowest energy absorption band was obtained. A simple way to achieve continuous single frequency laser operation using a grating as the sole tuning element is described. It is shown that, by proper choice of cavity parameters, the competing hole burning modes can be completely supressed. Experiments were carried out using Tl 0 (1) centers in KCl as the gain medium. The production of pulses via synchronous pumping of Tl 0 (1) color center in KCl are reported. (author) [pt

Seed coat color, weight and eye pattern inheritance in gamma-rays induced cowpea M2-mutant line

Directory of Open Access Journals (Sweden)

Reda M. Gaafar

2016-06-01

Full Text Available Gamma radiation is a very effective tool for inducing genetic variation in characters of many plants. Black seeds of M2 mutant were obtained after exposure of an Egyptian cowpea cultivar (Kaha 1 to a low dose of gamma rays. Segregation of seed coat color, weight of 100 seeds and seed eye pattern of the black seeds of this mutant line were further examined in this study. Four colors were observed for seed coat in the M3 plants ranging from cream to reddish brown and three eye patterns were distinguished from each other. SDS–PAGE of the seed storage proteins showed 18 protein bands; five of these bands disappeared in the seeds of M3 plants compared to M2 and M0 controls while other 5 protein bands were specifically observed in seeds of M3 plants. PCR analysis using twelve ISSR primers showed 47 polymorphic and 8 unique amplicons. The eight unique amplicons were characteristic of the cream coat color and brown wide eye pattern (M03-G10 while the polymorphic bands were shared by 6 coat-color groups. A PCR fragment of 850 bp was amplified, using primer HB-12, in M3-G04 which showed high-100 seed weight. These results demonstrated the mutagenic effects of gamma rays on seed coat color, weight of 100 seeds and eye pattern of cowpea M3 mutant plants.

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...

Splitting of photoluminescent emission from nitrogen–vacancy centers in diamond induced by ion-damage-induced stress

International Nuclear Information System (INIS)

Olivero, P; Bosia, F; Fairchild, B A; Gibson, B C; Greentree, A D; Spizzirri, P; Prawer, S

2013-01-01

We report a systematic investigation on the spectral splitting of negatively charged, nitrogen–vacancy (NV − ) photoluminescent emission in single-crystal diamond induced by strain engineering. The stress fields arise from MeV ion-induced conversion of diamond to amorphous and graphitic material in regions proximal to the centers of interest. In low-nitrogen sectors of a high-pressure–high-temperature diamond, clearly distinguishable spectral components in the NV − emission develop over a range of ∼4.8 THz corresponding to distinct alignment of sub-ensembles which were mapped with micron spatial resolution. This method provides opportunities for the creation and selection of aligned NV − centers for ensemble quantum information protocols. (paper)

Spatial profile of contours inducing long-range color assimilation.

Science.gov (United States)

Devinck, Frédéric; Spillmann, Lothar; Werner, John S

2006-01-01

Color induction was measured using a matching method for two spatial patterns, each composed of double contours. In one pattern (the standard), the contours had sharp edges to induce the Watercolor Effect (WCE); in the other, the two contours had a spatial taper so that the overall profile produced a sawtooth edge, or ramped stimulus. These patterns were chosen based on our previous study demonstrating that the strength of the chromatic WCE depends on a luminance difference between the two contours. Low-pass chromatic mechanisms, unlike bandpass luminance mechanisms, may be expected to be insensitive to the difference between the two spatial profiles. The strength of the watercolor spreading was similar for the two patterns at narrow widths of the contour possibly because of chromatic aberration, but with wider contours, the standard stimulus produced stronger assimilation than the ramped stimulus. This research suggests that luminance-dependent chromatic mechanisms mediate the WCE and that these mechanisms are sensitive to differences in the two spatial profiles of the pattern contours only when they are wide.

Study on two-color planar laser induced fluorescence thermometry

International Nuclear Information System (INIS)

Li Shaodan; Tan Sichao; Gao Puzhen; Lin Yuansheng

2014-01-01

Many of the convection heat transfer process are involved in the research of nuclear reactor thermal hydraulics. To experimentally determine the variation of the temperature field in those processes is important for the design and safety operation of the nuclear reactor. The application of the two-color planar laser induced fluorescence (PLIF) in the measurements of fluid temperature distribution is discussed in the paper. The laser dyes used here is rhodamine B (RhB) with negative temperature coefficient and fluorescein 27 (F127) with positive temperature coefficient. The beam of the laser light is adjusted to laser sheet by using the lens group. The fluid with dyes is excited by this laser sheet in a specific plane and temperature dependent fluorescence is released. The temperature field of the plane can be determined through the intensity information. Some technical aspects encountered in the application of the two-laser PLIF are discussed in the paper, such as the spectra characteristic of the dyes and the separation of the spectra. The calibration temperature is higher than the water saturation temperature (at atmosphere pressure). (authors)

Time-dependent broken-symmetry density functional theory simulation of the optical response of entangled paramagnetic defects: Color centers in lithium fluoride

Science.gov (United States)

Janesko, Benjamin G.

2018-02-01

Parameter-free atomistic simulations of entangled solid-state paramagnetic defects may aid in the rational design of devices for quantum information science. This work applies time-dependent density functional theory (TDDFT) embedded-cluster simulations to a prototype entangled-defect system, namely two adjacent singlet-coupled F color centers in lithium fluoride. TDDFT calculations accurately reproduce the experimental visible absorption of both isolated and coupled F centers. The most accurate results are obtained by combining spin symmetry breaking to simulate strong correlation, a large fraction of exact (Hartree-Fock-like) exchange to minimize the defect electrons' self-interaction error, and a standard semilocal approximation for dynamical correlations between the defect electrons and the surrounding ionic lattice. These results motivate application of two-reference correlated ab initio approximations to the M-center, and application of TDDFT in parameter-free simulations of more complex entangled paramagnetic defect architectures.

Gemstone color enhancement by electron beam irradiation-A preliminary study

International Nuclear Information System (INIS)

Sarada Idris; Zulkafli Ghazali; Shamshad Ahmad; Mohd Suhaimi Jusoh

2010-01-01

Treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9 MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones mined in Pakistan and elsewhere. The study shows that EB Irradiation not only enhances the color but also improves the clarity of the gemstones. The treated stones included kunzite tourmaline topaz quartz aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 kGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the rough and the faceted gems. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market. (author)

A color magnetic vortex condensate in QCD

International Nuclear Information System (INIS)

Ambjoern, J.; Olesen, P.

1980-03-01

It is shown that there exists a very close analogy between a lattice of vorticies in a superconductor near the critical field and a condensate of color magnetic flux tubes due to the unstable mode in QCD. This analogy makes it possible to identify a dynamical Higgs field in QCD. It is shown that the color magnetic flux tubes are quantized in terms of the center group Z(2) in the SU(2) case. In the case of SU(N) it is possible to select a color direction of the field such that one has Z(N) quantization. (Auth.)

Both "나" and "な" are yellow: cross-linguistic investigation in search of the determinants of synesthetic color.

Science.gov (United States)

Shin, Eun-hye; Kim, Chai-Youn

2014-12-01

Individuals with grapheme-color synesthesia experience "colors" when viewing achromatic letters and digits. Despite the large individual difference in synesthetic association between inducing graphemes and induced colors, the search for the determinants of synesthetic experience has begun. So far, however, research has drawn an inconsistent picture; some studies have shown that graphemes of similar visual shape tend to induce similar synesthetic colors, while others suggested sound as an important factor. Moreover, meaning seems to affect synesthetic color. In the present work, we sought to investigate the determinants of synesthetic color by testing four multilingual grapheme-color synesthetes who experience "colors" upon viewing Korean (hangul), Japanese (katakana and hiragana), and English (Latin alphabet) characters on a standardized color-matching procedure. Results showed that pairs of characters of matched sound tended to induce similar synesthetic colors. This was the case not only between two scripts within the same language (Japanese hiragana and katakana) but also between two different languages (Japanese and Korean). In addition, pairs of characters with similar initial phonemes tended to induce similar colors; this was general across multiple languages. Results also showed that pairs of sequential words in Korean, Japanese, English, and Chinese that have the same meaning tended to elicit similar synesthetic colors. When those pairs of words shared not only meaning but also sound, the similarity of the induced synesthetic colors was even greater. Our work is one of the few initial attempts to examine the influence of visual shape, sound, meaning, and their interaction on synesthetic color induced by characters across multiple languages. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of saturation and contrast polarity on the figure-ground organization of color on gray.

Science.gov (United States)

Dresp-Langley, Birgitta; Reeves, Adam

2014-01-01

Poorly saturated colors are closer to a pure gray than strongly saturated ones and, therefore, appear less "colorful."Color saturation is effectively manipulated in the visual arts for balancing conflicting sensations and moods and for inducing the perception of relative distance in the pictorial plane. While perceptual science has proven quite clearly that the luminance contrast of any hue acts as a self-sufficient cue to relative depth in visual images, the role of color saturation in such figure-ground organization has remained unclear. We presented configurations of colored inducers on gray "test" backgrounds to human observers. Luminance and saturation of the inducers was uniform on each trial, but varied across trials. We ran two separate experimental tasks. In the relative background brightness task, perceptual judgments indicated whether the apparent brightness of the gray test background contrasted with, assimilated to, or appeared equal (no effect) to that of a comparison background with the same luminance contrast. Contrast polarity and its interaction with color saturation affected response proportions for contrast, assimilation and no effect. In the figure-ground task, perceptual judgments indicated whether the inducers appeared to lie in front of, behind, or in the same depth with the background. Strongly saturated inducers produced significantly larger proportions of foreground effects indicating that these inducers stand out as figure against the background. Weakly saturated inducers produced significantly larger proportions of background effects, indicating that these inducers are perceived as lying behind the backgrounds. We infer that color saturation modulates figure-ground organization, both directly by determining relative inducer depth, and indirectly, and in interaction with contrast polarity, by affecting apparent background brightness. The results point toward a hitherto undocumented functional role of color saturation in the genesis of

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

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.

Effects of saturation and contrast polarity on the figure-ground organization of color on grey

Directory of Open Access Journals (Sweden)

Birgitta eDresp

2014-10-01

Full Text Available Poorly saturated colors are closer to a pure grey than strongly saturated hues and, therefore, appear less colorful. Color saturation is effectively manipulated in the visual arts for balancing conflicting sensations and moods and for inducing the perception of relative distance in the pictorial plane. While perceptual science has proven quite clearly that the luminance contrast of any hue acts as a self-sufficient cue to relative depth in visual images, the role of color saturation in such figure-ground organization has remained unclear. We presented configurations of colored inducers on grey ‘test’ backgrounds to human observers. Luminance and saturation of the inducers was uniform on each trial, but varied across trials. We ran two separate experimental tasks. In the relative background brightness task, perceptual judgments indicated whether the apparent brightness of the grey test background contrasted with, assimilated to, or appeared equal (no effect to that of a comparison background with the same luminance contrast. Contrast polarity and its interaction with color saturation affected response proportions for contrast, assimilation and no effect. In the figure-ground task, perceptual judgments indicated whether the inducers appeared to lie in front of, behind, or in the same depth with the background. Strongly saturated inducers produced larger proportions of foreground effects indicating that these inducers stand out as figure against the background. Weakly saturated inducers produced significantly larger proportions of background effects, indicating that these inducers are perceived as lying behind the backgrounds. We infer that color saturation modulates figure-ground organization, both directly by determining relative inducer depth, and indirectly, and in interaction with contrast polarity, by affecting apparent background brightness.

Spatial Distribution of Flower Color Induced by Interspecific Sexual Interaction.

Directory of Open Access Journals (Sweden)

Yuma Takahashi

Full Text Available Understanding the mechanisms shaping the spatiotemporal distribution of species has long been a central concern of ecology and evolutionary biology. Contemporary patterns of plant assemblies suggest that sexual interactions among species, i.e., reproductive interference, lead to the exclusive distributions of closely related species that share pollinators. However, the fitness consequences and the initial ecological/evolutionary responses to reproductive interference remain unclear in nature, since reproductive isolation or allopatric distribution has already been achieved in the natural community. In Japan, three species of blue-eyed grasses (Sisyrinchium with incomplete reproductive isolation have recently colonized and occur sympatrically. Two of them are monomorphic with white flowers, whereas the other exhibits heritable color polymorphism (white and purple morphs. Here we investigated the effects of the presence of two monomorphic species on the distribution and reproductive success of color morphs. The frequency and reproductive success of white morphs decreased in area where monomorphic species were abundant, while those of purple morphs did not. The rate of hybridization between species was higher in white morphs than in the purple ones. Resource competition and habitat preference seemed not to contribute to the spatial distribution and reproductive success of two morphs. Our results supported that color-dependent reproductive interference determines the distribution of flower color polymorphism in a habitat, implying ecological sorting promoted by pollinator-mediated reproductive interference. Our study helps us to understand the evolution and spatial structure of flower color in a community.

Contribution to the study of the responsable mechanisms by the radiative formation of color centers in doped KBr crystals with alkaline earth impurities

International Nuclear Information System (INIS)

Muccillo, R.

1977-01-01

Experiments utilizing the tecniques Optical Absorption in the visible and ultraviolet spectral regions, thermally Stimulated Depolarization Currents (TSDC) in the 120K - 300K temperature range, and Thermoluminescence in the 290K - 620K temperature range - are perform to study radiative production, and thermal and optical destruction of color centers in Sr-droped KBr crystals. Some of the main results are also obtoned from experiments with Ca-deped KBr crystais [pt

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.

Gray Bananas and a Red Letter A - From Synesthetic Sensation to Memory Colors.

Science.gov (United States)

Weiss, Franziska; Greenlee, Mark W; Volberg, Gregor

2018-01-01

Grapheme-color synesthesia is a condition in which objectively achromatic graphemes induce concurrent color experiences. While it was long thought that the colors emerge during perception, there is growing support for the view that colors are integral to synesthetes' cognitive representations of graphemes. In this work, we review evidence for two opposing theories positing either a perceptual or cognitive origin of concurrent colors: the cross-activation theory and the conceptual-mediation model. The review covers results on inducer and concurrent color processing as well as findings concerning the brain structure and grapheme-color mappings in synesthetes and trained mappings in nonsynesthetes. The results support different aspects of both theories. Finally, we discuss how research on memory colors could provide a new perspective in the debate about the level of processing at which the synesthetic colors occur.

Structural coloration of chitosan-cationized cotton fabric using photonic crystals

Science.gov (United States)

Yavuz, G.; Zille, A.; Seventekin, N.; Souto, A. P.

2017-10-01

In this work, poly (styrene-methyl methacrylate-acrylic acid) P(St-MMA-AA) composite nanospheres were deposited onto chitosan-cationized woven cotton fabrics followed by a second layer of chitosan. The deposited photonic crystals (PCs) on the fabrics were evaluated for coating efficiency and resistance, chemical analysis and color variation by optical and SEM microscopy, ATR-FTIR, diffuse reflectance spectroscopy and washing fastness. Chitosan deposition on cotton fabric provided cationic groups on the fiber surface promoting electrostatic interaction with photonic crystals. SEM images of the washed samples indicate that the PCs are firmly coated on the cotton surface only in the chitosan treated sample. The photonic nanospheres show an average diameter of 280 nm and display a face-centered cubic closepacking structure with an average thickness of 10 μm. A further chitosan post-treatment enhances color yield of the samples due to the chitosan transparent covering layer that induce bright reflections where the angles of incidence and reflection are the same. After washing, no photonic crystal can be detected on control fabric surface. However, the sample that received a chitosan post-treatment showed a good washing fastness maintaining a reasonable degree of iridescence. Chitosan fills the spaces between the polymer spheres in the matrix stabilizing the photonic structure. Sizeable variations in lattice spacing will allow color variations using more flexible non-close-packed photonic crystal arrays in chitosan hydrogels matrices.

P1-9: Relationship between Color Shifts in Land's Two-Color Method and Higher- and Lower-Level Visual Information

Directory of Open Access Journals (Sweden)

Saki Iwaida

2012-10-01

Full Text Available Land's two-color method gives rise to apparent full-color perception, even though only two colors (e.g., red and gray are used. Previous studies indicate that chromatic adaptation, color memory, and inductive effects contribute to the shifts of color perception from real to illusory colors (e.g., Kuriki, 2006 Vision Research 46 3055–3066. This paper investigates the relationship between the color shifts induced by Land images and the skewness of the luminance histogram. In Experiment 1, several Land images are created based on a yellow ball, and the magnitude of the color shifts of the images are measured. The results of Experiment 1 show a significant correlation between the magnitude of the color shifts and skewness, suggesting that skewness is critical for the color shifts. In Experiment 2, we test the hypothesis that color shifts depends on just skewness; the color shifts should be invariant even if the Land images are scrambled. However, the results of Experiment 2 demonstrate that scrambled Land images exhibit less intense color shifts, suggesting that color shifts are determined by the object's overall shape or surface gloss, not just skewness. Taken together, we conclude that both low-level visual processes, such as those associated with luminance histogram skew, and high-level cognitive functions, such as object interpretation or understanding of surface gloss, are involved in the color shift of Land images.

Many-electron states of the N2 and N3 color centers in diamond: A first- principles and many-body study

Energy Technology Data Exchange (ETDEWEB)

Babamoradi, Mohsen, E-mail: babamoradi@iust.ac.ir [Department of Physics, Iran University of Science and Technology, Narmak,16846-13114 Tehran (Iran, Islamic Republic of); Asgari, Sussan [Department of Physics, Iran University of Science and Technology, Narmak,16846-13114 Tehran (Iran, Islamic Republic of); Ranjbar, Ahmad [Computational Materials Science Research Team, RIKEN Advanced Institute for Computational Science, Kobe, Hyogo 650-0047 (Japan); Belosludov, Rodion V. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Yunoki, Seiji [Computational Materials Science Research Team, RIKEN Advanced Institute for Computational Science, Kobe, Hyogo 650-0047 (Japan); Computational Condensed Matter Physics Laboratory, RIKEN, Wako, Saitama 351-0198 (Japan); Computational Quantum Matter Research Team, RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198 (Japan)

2017-01-15

A new model is applied to calculate the many-body properties of the neutral N3 color center in diamond. This model is based on the first-principles density functional theory (DFT) and cluster method, which is combined with the generalized Hubbard model. In contrast to the previous models for N3 centers, our model does not require the configuration interaction (CI) and molecular orbital (MO) techniques. The N3 defect in diamond is simulated with an empty site next to three substitutional nitrogen atoms in the center of a hydrogen-terminated diamond cluster. The method is shown to be highly accurate for describing the symmetries and spin properties of the ground state and the first dipole-allowed excited state for the N3 center. We obtain the transition energy as 412 nm for the first dipole-allowed transition, which is in good agreement with the corresponding experimental value as 415 nm. We assigned the dipole-allowed transition between the first and second excited states as the N2 optical peak, and evaluated the N2 optical peak to be 463 nm, which is close to the experimental value as 478 nm.

Effective Connectivity Determines the Nature of Subjective Experience in Grapheme-Color Synesthesia

NARCIS (Netherlands)

Leeuwen, T.M. van; Ouden, H.E.M. den; Hagoort, P.

2011-01-01

Synesthesia provides an elegant model to investigate neural mechanisms underlying individual differences in subjective experience in humans. In grapheme-color synesthesia, written letters induce color sensations, accompanied by activation of color area V4. Competing hypotheses suggest that enhanced

Human attention filters for single colors

Science.gov (United States)

Sun, Peng; Chubb, Charles; Wright, Charles E.; Sperling, George

2016-01-01

The visual images in the eyes contain much more information than the brain can process. An important selection mechanism is feature-based attention (FBA). FBA is best described by attention filters that specify precisely the extent to which items containing attended features are selectively processed and the extent to which items that do not contain the attended features are attenuated. The centroid-judgment paradigm enables quick, precise measurements of such human perceptual attention filters, analogous to transmission measurements of photographic color filters. Subjects use a mouse to locate the centroid—the center of gravity—of a briefly displayed cloud of dots and receive precise feedback. A subset of dots is distinguished by some characteristic, such as a different color, and subjects judge the centroid of only the distinguished subset (e.g., dots of a particular color). The analysis efficiently determines the precise weight in the judged centroid of dots of every color in the display (i.e., the attention filter for the particular attended color in that context). We report 32 attention filters for single colors. Attention filters that discriminate one saturated hue from among seven other equiluminant distractor hues are extraordinarily selective, achieving attended/unattended weight ratios >20:1. Attention filters for selecting a color that differs in saturation or lightness from distractors are much less selective than attention filters for hue (given equal discriminability of the colors), and their filter selectivities are proportional to the discriminability distance of neighboring colors, whereas in the same range hue attention-filter selectivity is virtually independent of discriminabilty. PMID:27791040

Optical properties of T-centers under gamma irradiation

CERN Document Server

Polosan, S; Dragusin, M; Topa, V

2003-01-01

Electrolytic coloring of KCl:Pb crystals, leads to formation of negative metal ions with intense emission in the infrared region. These new color centers were named T centers; their most probable configuration could be Pb sub 2 sup 2 sup - , due to the lack of EPR or DCM signals. In order to destroy these structures, the crystals were irradiated with gamma-rays at high doses. The results were the detachment of the electrons from T centers and the appearance of Pb sup 2 sup + - ions. The possibility cannot be excluded of the existence of Pb sup + and Pb sup 0 centers in the samples, because these centers do not exhibit any optical properties on this spectral region. (authors)

Disruptive Effects of Colorful versus Non-Colorful Play Area on Structured Play – a Pilot Study with Preschoolers

Directory of Open Access Journals (Sweden)

Keren Stern-Ellran

2016-10-01

Full Text Available To contribute to young children's development, sensory enrichment is often provided via colorful play areas. However, little is known about the effects of colorful environments on children while they engage in age-appropriate tasks and games. Studies in adults suggest that aspects of color can distract attention and impair performance, and children are known to have less developed attentional and executive abilities than adults. Preliminary studies conducted in children aged 5-8 suggest that the colorfulness of both distal (e.g., wall decorations and proximal (e.g., the surface of the desktop environments can have a disruptive effect on children's performance. The present research seeks to extend the previous studies to an even younger age group and focus on proximal colorfulness. With a sample of 15 pre-schoolers (3-4 years old we examined whether a colorful play surface compared to a non-colorful (white play surface would affect engagement in developmentally appropriate structured play. Our pilot findings suggest that a colorful play surface interfered with preschoolers' structured play, inducing more behaviors indicating disruption in task execution compared with a non-colorful play surface. The implications of the current study for practice and further research are discussed.

Why some colors appear more memorable than others: A model combining categories and particulars in color working memory.

Science.gov (United States)

Bae, Gi-Yeul; Olkkonen, Maria; Allred, Sarah R; Flombaum, Jonathan I

2015-08-01

Categorization with basic color terms is an intuitive and universal aspect of color perception. Yet research on visual working memory capacity has largely assumed that only continuous estimates within color space are relevant to memory. As a result, the influence of color categories on working memory remains unknown. We propose a dual content model of color representation in which color matches to objects that are either present (perception) or absent (memory) integrate category representations along with estimates of specific values on a continuous scale ("particulars"). We develop and test the model through 4 experiments. In a first experiment pair, participants reproduce a color target, both with and without a delay, using a recently influential estimation paradigm. In a second experiment pair, we use standard methods in color perception to identify boundary and focal colors in the stimulus set. The main results are that responses drawn from working memory are significantly biased away from category boundaries and toward category centers. Importantly, the same pattern of results is present without a memory delay. The proposed dual content model parsimoniously explains these results, and it should replace prevailing single content models in studies of visual working memory. More broadly, the model and the results demonstrate how the main consequence of visual working memory maintenance is the amplification of category related biases and stimulus-specific variability that originate in perception. (c) 2015 APA, all rights reserved).

Factors influencing internal color of cooked meats.

Science.gov (United States)

Suman, Surendranath P; Nair, Mahesh N; Joseph, Poulson; Hunt, Melvin C

2016-10-01

This manuscript overviews the pertinent research on internal color of uncured cooked meats, biochemical processes involved in meat cookery, and fundamental mechanisms governing myoglobin thermal stability. Heat-induced denaturation of myoglobin, responsible for the characteristic dull-brown color of cooked meats, is influenced by a multitude of endogenous (i.e., pH, muscle source, species, redox state) and exogenous (i.e., packaging, ingredients, storage) factors. The interactions between these factors critically influence the internal cooked color and can confuse the consumers, who often perceive cooked color to be a reliable indicator for doneness and safety. While certain phenomena in cooked meat color are cosmetic in nature, others can mislead consumers and result in foodborne illnesses. Research in meat color suggests that processing technologies and cooking practices in industry as well as households influence the internal cooked color. Additionally, the guidelines of many international public health and regulatory authorities recommend using meat thermometers to determine safe cooking endpoint temperature and to ensure product safety. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can Coloring Mandalas Reduce Anxiety? A Replication Study

Science.gov (United States)

van der Vennet, Renee; Serice, Susan

2012-01-01

This experimental study replicated Curry and Kasser's (2005) research that tested whether coloring a mandala would reduce anxiety. After inducing an anxious mood via a writing activity, participants were randomly assigned to three groups that colored either on a mandala design, on a plaid design, or on a blank paper. Anxiety level was measured…

On the classification of elliptic foliations induced by real quadratic fields with center

Science.gov (United States)

Puchuri, Liliana; Bueno, Orestes

2016-12-01

Related to the study of Hilbert's infinitesimal problem, is the problem of determining the existence and estimating the number of limit cycles of the linear perturbation of Hamiltonian fields. A classification of the elliptic foliations in the projective plane induced by the fields obtained by quadratic fields with center was already studied by several authors. In this work, we devise a unified proof of the classification of elliptic foliations induced by quadratic fields with center. This technique involves using a formula due to Cerveau & Lins Neto to calculate the genus of the generic fiber of a first integral of foliations of these kinds. Furthermore, we show that these foliations induce several examples of linear families of foliations which are not bimeromorphically equivalent to certain remarkable examples given by Lins Neto.

Gray Bananas and a Red Letter A — From Synesthetic Sensation to Memory Colors

Science.gov (United States)

Weiss, Franziska; Volberg, Gregor

2018-01-01

Grapheme–color synesthesia is a condition in which objectively achromatic graphemes induce concurrent color experiences. While it was long thought that the colors emerge during perception, there is growing support for the view that colors are integral to synesthetes’ cognitive representations of graphemes. In this work, we review evidence for two opposing theories positing either a perceptual or cognitive origin of concurrent colors: the cross-activation theory and the conceptual-mediation model. The review covers results on inducer and concurrent color processing as well as findings concerning the brain structure and grapheme–color mappings in synesthetes and trained mappings in nonsynesthetes. The results support different aspects of both theories. Finally, we discuss how research on memory colors could provide a new perspective in the debate about the level of processing at which the synesthetic colors occur. PMID:29899968

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…

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

Optical spectroscopy and microscopy of radiation-induced light-emitting point defects in lithium fluoride crystals and films

Science.gov (United States)

Montereali, R. M.; Bonfigli, F.; Menchini, F.; Vincenti, M. A.

2012-08-01

Broad-band light-emitting radiation-induced F2 and F3+ electronic point defects, which are stable and laser-active at room temperature in lithium fluoride crystals and films, are used in dosimeters, tuneable color-center lasers, broad-band miniaturized light sources and novel radiation imaging detectors. A brief review of their photoemission properties is presented, and their behavior at liquid nitrogen temperatures is discussed. Some experimental data from optical spectroscopy and fluorescence microscopy of these radiation-induced point defects in LiF crystals and thin films are used to obtain information about the coloration curves, the efficiency of point defect formation, the effects of photo-bleaching processes, etc. Control of the local formation, stabilization, and transformation of radiation-induced light-emitting defect centers is crucial for the development of optically active micro-components and nanostructures. Some of the advantages of low temperature measurements for novel confocal laser scanning fluorescence microscopy techniques, widely used for spatial mapping of these point defects through the optical reading of their visible photoluminescence, are highlighted.

Is the color trails culture free?

Science.gov (United States)

Fasfous, Ahmed F; Puente, Antonio E; Pérez-Marfil, María Nieves; Cruz-Quintana, Francisco; Peralta-Ramirez, Isabel; Pérez-García, Miguel

2013-11-01

Increasingly clinical neuropsychology has been addressing the effects of culture on neuropsychological functioning. However, that focus has been on comparing performance on standardized tests across two or more groups, often Hispanic. In this study, Arabic children were tested in Morocco using a "culture-free test," Children's Color Trails. Children of different ages and living in rural and urban centers were tested. The results suggest that the Color Trails Test scores from Arab children differed from U.S. norms available. Furthermore, the location of testing and the age of the child were of significance. The role of culture-specific tests was considered.

Loving transgressions: Queer of color bodies, affective ties, transformative community.

Science.gov (United States)

Carrillo Rowe, Aimee; Royster, Francesca T

2017-07-03

This introductory article considers the importance of queer woman of color theorizations of affect in thinking more fully the recent interdisciplinary turn to affect. The affective turn has vitally invited culture and feminist critics to interrogate emotion beyond the individual to examine the political and cultural production of emotion. Even as women of color are often associated with excessive affect, the theoretical contributions women of color make to the field of affect studies are often overlooked. Our introduction and this special issue more broadly examine how this solipsism shapes projects invested in critical knowledge production, as well as the stakes of centering a queer woman of color genealogy. For instance, we argue for the importance of retaining U.S. third-world feminist concepts-like interpellation, oppositional consciousness, and the generative force of negative affects-even as they fall out of favor within affect studies. Centering theory that emerges from the vexed spaces of queer women of color lived experiences generates a vital interdisciplinary conversation that contributes to the ongoing political task of mobilizing affect for social action as a critical praxis. In the articles that follow we see this critical praxis at work in the form of community organizing, music, poetry, and performance art.

P1-10: The Association between Colors and Emotions

OpenAIRE

Yen-Yu Chen; Chih-Hao Lien; Cho-Han Yang; Yi-Jae Jhong; Tsun-Yu Chen; Shiau-Hua Liu

2012-01-01

Wexner (1954 Journal of Applied Psychology 38 432–435) demonstrated colors were associated with specific emotions. Colors have many meanings, such as that red can lead to induce positive or negative emotions (Kaya & Epps, 2011 College Student Journal 38 396–406). This study extends previous findings and aims to investigate two questions, (1) whether colors are associated with the emotions of pictures in IAPS (International Affective Picture System) and (2) whether perceiving IAPS consciously ...

Color superconductivity in dense quark matter

International Nuclear Information System (INIS)

Alford, Mark G.; Schmitt, Andreas; Rajagopal, Krishna; Schaefer, Thomas

2008-01-01

Matter at high density and low temperature is expected to be a color superconductor, which is a degenerate Fermi gas of quarks with a condensate of Cooper pairs near the Fermi surface that induces color Meissner effects. At the highest densities, where the QCD coupling is weak, rigorous calculations are possible, and the ground state is a particularly symmetric state, the color-flavor locked (CFL) phase. The CFL phase is a superfluid, an electromagnetic insulator, and breaks chiral symmetry. The effective theory of the low-energy excitations in the CFL phase is known and can be used, even at more moderate densities, to describe its physical properties. At lower densities the CFL phase may be disfavored by stresses that seek to separate the Fermi surfaces of the different flavors, and comparison with the competing alternative phases, which may break translation and/or rotation invariance, is done using phenomenological models. We review the calculations that underlie these results and then discuss transport properties of several color-superconducting phases and their consequences for signatures of color superconductivity in neutron stars.

Jets in QCD Media: Onset of Color Decoherence

International Nuclear Information System (INIS)

Mehtar-Tani, Y.; Salgado, C.A.; Tywoniuk, K.

2011-01-01

We report on recent studies of the phenomenon of color decoherence of jets in QCD media. The effect is most clearly observed in the radiation pattern of a quark-antiquark antenna, created in the same quantum state, traversing a dense color deconfined plasma. Multiple scattering with the medium color charges gradually destroys the coherence of the antenna. In the limit of opaque media this ultimately leads to independent radiation off the antenna constituents. Accordingly, radiation off the total charge vanishes implying a memory loss effect induced by the medium. (authors)

Selective appearance of several laser-induced periodic surface structure patterns on a metal surface using structural colors produced by femtosecond laser pulses

Energy Technology Data Exchange (ETDEWEB)

Yao Jianwu; Zhang Chengyun; Liu Haiying; Dai Qiaofeng; Wu Lijun [Laboratory of Photonic Information Technology, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China); Lan, Sheng, E-mail: slan@scnu.edu.cn [Laboratory of Photonic Information Technology, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 (China); Gopal, Achanta Venu [Department of Condensed Matter Physics and Material Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Trofimov, Vyacheslav A.; Lysak, Tatiana M. [Department of Computational Mathematics and Cybernetics, M. V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation)

2012-07-15

Ripples with a subwavelength period were induced on the surface of a stainless steel (301 L) foil by femtosecond laser pulses. By optimizing the irradiation fluence of the laser pulses and the scanning speed of the laser beam, ripples with large amplitude ({approx}150 nm) and uniform period could be obtained, rendering vivid structural colors when illuminating the surface with white light. It indicates that these ripples act as a surface grating that diffracts light efficiently. The strong dependence of the ripple orientation on the polarization of laser light offers us the opportunity of decorating different regions of the surface with different types of ripples. As a result, different patterns can be selectively displayed with structural color when white light is irradiated on the surface from different directions. More interestingly, we demonstrated the possibility of decorating the same region with two or more types of ripples with different orientations. In this way, different patterns with spatial overlapping can be selectively displayed with structural color. This technique may find applications in the fields of anti-counterfeiting, color display, decoration, encryption and optical data storage.

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.

Confocal fluorescence microscopy investigation of visible emitting defects induced by electron beam lithography in LIF films

Energy Technology Data Exchange (ETDEWEB)

Montereali, R.M.; Bigotta, S.; Pace, A.; Piccinini, M. [ENEA, Divisione Fisica Applicata, Centro Ricerche Frascati, Frascati, RM (Italy); Burattini, E.; Grilli, A.; Raco, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Fisica, Frascati, Rome (Italy); Giammatteo, M. [Unita' Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy)]|[L' Aquila Univ., L' Aquila (Italy). Centro di Microscopia Elettronica; Picozzi, P.; Santucci, S. [Unita' Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy)]|[L' Aquila Univ., L' Aquila (Italy). Dipt. di Fisica

2000-07-01

Low energy electron irradiation of lithium fluoride (LiF), in the form of bulk crystals and films, gives rise to the stable formation of primary F defects and aggregated color centers in a thin layer located at the surface of the investigated material. For the first time a confocal light scanning microscope (CLSM) in fluorescence mode was used to reconstruct the depth distribution of efficiently emitting laser active color centers in a stripe-like region induced by 12 and 16 keV electrons on LiF films thermally evaporated on glass. The formation of the F{sub 3}{sup +} and F{sub 2} aggregated defects appears restricted to the electron penetration and proportional to their energy depth profile, as obtained from Monte Carlo simulations. [Italian] L'irraggiamento con elettroni di bassa energia del fluoruro di litio (LiF), in forma di cristalli e film, induce la formazione di difetti primari F e centri di colore aggregati stabili in un sottile strato localizzato alla superficie del materiale investigato. Per la prima volta un microscopio confocale a scansione (CLSM) in modalita' fluorescenza e' stato usato per ricostruire la distribuzione di centri di colore laser attivi ad alta efficienza di emissione nel visibile, in strisce colorate ottenute con elettroni da 12 e 16 keV su film di LiF evaporati termicamente su vetro. La formazione dei difetti aggregati F2 e F3+ risulta ristretta spazialmente nella regione di penetrazione degli elettroni e proporzionale al profilo della distribuzione dell'energia da essi depositata, ricavata tramite simulazioni Monte Carlo.

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.

The watercolor effect: quantitative evidence for luminance-dependent mechanisms of long-range color assimilation.

Science.gov (United States)

Devinck, Frédéric; Delahunt, Peter B; Hardy, Joseph L; Spillmann, Lothar; Werner, John S

2005-05-01

When a dark chromatic contour delineating a figure is flanked on the inside by a brighter chromatic contour, the brighter color will spread into the entire enclosed area. This is known as the watercolor effect (WCE). Here we quantified the effect of color spreading using both color-matching and hue-cancellation tasks. Over a wide range of stimulus chromaticities, there was a reliable shift in color appearance that closely followed the direction of the inducing contour. When the contours were equated in luminance, the WCE was still present, but weak. The magnitude of the color spreading increased with increases in luminance contrast between the two contours. Additionally, as the luminance contrast between the contours increased, the chromaticity of the induced color more closely resembled that of the inside contour. The results support the hypothesis that the WCE is mediated by luminance-dependent mechanisms of long-range color assimilation.

Color maps of X-ray globular clusters

International Nuclear Information System (INIS)

Bailyn, C.D.; Grindlay, J.E.; Cohn, H.; Lugger, P.M.

1988-01-01

The results of a search for optical counterparts to X-ray sources in six globular clusters, 47 Tuc, NGC 1851, NGC 6441, NGC 6624, NGC 6712, and M15, are reported. Maps of the U-B color of the central regions of the clusters were prepared. A candidate for the optical counterpart of the source in NGC 6712 was found, along with a blue region near the X-ray source in 47 Tuc. Upper limits on the colors and magnitudes of possible optical counterparts are reported for the other three clusters. The use of color maps to determine color gradients in globular clusters is explored. It is found that, while such gradients do exist and vary from cluster to cluster, they can be explained by crowding effects. Crude limits are placed on the excess populations of blue objects such as CVs, which have been postulated to be concentrated in the centers of dense clusters. 32 references

Color-pattern evolution in response to environmental stress in butterflies

Directory of Open Access Journals (Sweden)

Atsuki eHiyama

2012-02-01

Full Text Available It is generally accepted that butterfly wing color patterns have ecological and behavioral functions that evolved through natural selection. However, particular wing color patterns may physiologically be produced in response to environmental stress without significant function. These patterns would represent an extreme expression of phenotypic plasticity and can eventually be fixed genetically in a population. Here, three such cases in butterflies are concisely reviewed and their possible mechanisms of genetic assimilation are discussed. First, certain modified color pattern of Vanessa indica induced by temperature treatments resembles the natural color patterns of its closely related species of the genus Vanessa (sensu stricto. Second, a different type of color-pattern modification can be induced in Vanessa cardui as a result of a general stress response, which is very similar to the natural color pattern of its sister species Vanessa kershawi. Third, a field observation was reported, together with experimental support, to show that the color-pattern diversity of a regional population of Zizeeria maha increased at the northern range margin of this species in response to temperature stress. In these three cases, modified color patterns are unlikely to have significant functions, and these cases suggest that phenotypic plasticity plays an important role in butterfly wing color-pattern evolution. A neutral or non-functional trait can be assimilated genetically if it is linked, like a parasitic trait, with another functional trait. In addition, it is possible that environmental stress causes epigenetic modifications of genes related to color patterns and that their transgenerational inheritance facilitates the process of genetic assimilation of a neutral or non-functional trait.

Color formation on irradiated polystyrene by electrons beam; Formacao de cor no poliestireno irradiado com feixes de eletrons

Energy Technology Data Exchange (ETDEWEB)

Nardi, Daniela T.; Guedes, Selma M.L. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: smguedes@ipen.br

2005-07-01

The color formation on national and commercial polystyrene (PS) irradiated by electrons beam was investigated in function of dose (0-150 kGy), post-irradiation time (0-31 days) and heating by colorimetry (CIELab), electron spectroscopy resonance (RPE) and photoacoustic infrared spectroscopy (FTIR-PAS). Visually or by colorimetric parameters the radiation became the PS yellow and dark which intensified by increase the dose and disappeared after the post-irradiation time. Variations of green/red colors were insignificant. After post irradiation time of 30 days (150 kGy) or the heating (150 kGy) both yellow color and darkening decreased significantly showing the unstable color centers formation during the irradiation. The RPE spectra indicated that the radicals can be responsible by the formation of these color centers but there can not be responsible s by stable color centers. The FTIR-PAS spectra did not show the presence of different functional groups after irradiation. The PS studied can be radiosterilized (25 kGy) without significant colorimetric changes because it is radioresistant. (author)

Automatic color preference correction for color reproduction

Science.gov (United States)

Tsukada, Masato; Funayama, Chisato; Tajima, Johji

2000-12-01

The reproduction of natural objects in color images has attracted a great deal of attention. Reproduction more pleasing colors of natural objects is one of the methods available to improve image quality. We developed an automatic color correction method to maintain preferred color reproduction for three significant categories: facial skin color, green grass and blue sky. In this method, a representative color in an object area to be corrected is automatically extracted from an input image, and a set of color correction parameters is selected depending on the representative color. The improvement in image quality for reproductions of natural image was more than 93 percent in subjective experiments. These results show the usefulness of our automatic color correction method for the reproduction of preferred colors.

Frequency of color blindness in pre-employment screening in a tertiary health care center in Pakistan.

Science.gov (United States)

Chhipa, Shaukat Ali; Hashmi, Farzeen K; Ali, Shehreen; Kamal, Mustafa; Ahmad, Khabir

2017-01-01

To describe the frequency of color vision deficiency among Pakistani adults presenting for pre-employment health screening in a tertiary care hospital. The cross-sectional study was carried out at the Aga Khan University Hospital, Karachi, and the data was collected for color vision deficiency, age, gender, and job applied for from pre-employment examination during 2013-2014. IBM SPSS 20 was used for statistical analysis. Three thousand four hundred and thirty seven persons underwent pre-employment screening during 2013 and 2014; 1837 (53.44%) were males and 1600 (46.65%) females. The mean age was 29.01 (±6.53) years. A total of 0.9% (32/3437) persons had color vision deficiency with male being 1.4% and female 0.4%. Color vision deficiency was observed in 0.9% of candidates screened for pre-employment health check up in a tertiary care hospital. The color vision deficiency was predominantly present in male individuals.

Enhancement of color and clarity in topaz and diamonds by nuclear radiation, safety and security concerns

International Nuclear Information System (INIS)

Shamshad Ahmed

2009-01-01

Inducement of color and clarity in gemstone Topaz, otherwise devoid of these attributes, has been achieved by synergistic utilization of neutron irradiation, electron beam irradiation and heat. The transformation of the colorless, cheaply available topaz into desirable deep blue topaz is a significant value addition, not achievable by other contending techniques .Likewise colorless and unclear diamonds, available in trade at throw away price, have been transformed by neutron irradiation into colored diamonds, known as fancy diamonds. The enhanced gems may possess stable or unstable colors depending on the nature of the color centers produced. In the case of blue topaz and fancy diamonds the colors produced were stable and heating at elevated temperatures can only lead to fading of colors. The enhancement of gems by neutron irradiation is commercially viable provided appropriate equipment and tools are used .In the paper are described the processes of the enhancement of topaz and diamonds along with the instrumentation involved. However, in view of the radioactivity generated as a result of the exposure of gems to the neutrons, and the likelihood of undue exposure of the users, operators etc to the radioactive gems, safety aspects command serious attention. In the paper, the strategies to avoid or to mitigate the radioactivity generated have been discussed. Also documented are the methodologies and the controls to ensure that the radioactive gems are not released before ensuring that the radioactivity, if any, in the irradiated materials is not above the permissible levels in conformity with the international standards. Safety, security and safeguard of these materials are thus appropriately addressed. (Authors)

β-Cryptoxanthin and Zeaxanthin Pigments Accumulation to Induce Orange Color on Citrus Fruits

Science.gov (United States)

Hidayati Sumiasih, Inanpi; Poerwanto, Roedhy; Efendi, Darda; Agusta, Andria; Yuliani, Sri

2018-01-01

Degreening, a transformation process of green color on citrus peel to be orange color on tropical low-land citrus fruits often fails. Orange color of the citrus peel comes from the mixture carotenoid pigments, such as zeaxanthine and mainly β-cryptoxanthin and β-citraurin. The accumulation of β-citraurin occurs when the fruits are exposed to low temperature, and otherwise, it will fail to occur. Precooling treatment on lowland tropical citrus fruits is expected to stimulate the accumulation of β-citraurin. The results showed the most favorable color obtained from precooling and 24-hour ethylene exposure duration. This treatment could decrease total chlorophyll and β-carotene content as well as proven to increase 3 times the accumulation of β-cryptoxanthin in accelerating the appearance of bright orange color on citrus peel. Degreening gave no significant effect to internal quality of Citrus reticulata.

Future of laser electrophotographic technology for color document printing

Science.gov (United States)

Shahin, Michael M.

1997-04-01

Recent years have witnessed the development of laser electrophotography as one of the major technologies for document printing, serving a wide range of market applications. With the evolution of color and market demand for color hard copy, electrophotography is again taking center stage to serve the customer need in quality, cost and convenience. Today, electrophotographic technology is used to offer products for color document printing for desktop, mid-volume and high-speed applications. Total cost of ownership, convenience and quality today favor the use of this technology over alternatives in many applications. Development of higher speed color electrophotographic engines demands very high speed, Raster Input Processors and pre-press applications that are expected to become available in the market during the next five years. This presentation will cover the changing environment of office communication and the continuing role of electrophotography in color document printing.

Enhanced dimension-specific visual working memory in grapheme–color synesthesia☆

Science.gov (United States)

Terhune, Devin Blair; Wudarczyk, Olga Anna; Kochuparampil, Priya; Cohen Kadosh, Roi

2013-01-01

There is emerging evidence that the encoding of visual information and the maintenance of this information in a temporarily accessible state in working memory rely on the same neural mechanisms. A consequence of this overlap is that atypical forms of perception should influence working memory. We examined this by investigating whether having grapheme–color synesthesia, a condition characterized by the involuntary experience of color photisms when reading or representing graphemes, would confer benefits on working memory. Two competing hypotheses propose that superior memory in synesthesia results from information being coded in two information channels (dual-coding) or from superior dimension-specific visual processing (enhanced processing). We discriminated between these hypotheses in three n-back experiments in which controls and synesthetes viewed inducer and non-inducer graphemes and maintained color or grapheme information in working memory. Synesthetes displayed superior color working memory than controls for both grapheme types, whereas the two groups did not differ in grapheme working memory. Further analyses excluded the possibilities of enhanced working memory among synesthetes being due to greater color discrimination, stimulus color familiarity, or bidirectionality. These results reveal enhanced dimension-specific visual working memory in this population and supply further evidence for a close relationship between sensory processing and the maintenance of sensory information in working memory. PMID:23892185

Embedding Color Watermarks in Color Images

Directory of Open Access Journals (Sweden)

Wu Tung-Lin

2003-01-01

Full Text Available Robust watermarking with oblivious detection is essential to practical copyright protection of digital images. Effective exploitation of the characteristics of human visual perception to color stimuli helps to develop the watermarking scheme that fills the requirement. In this paper, an oblivious watermarking scheme that embeds color watermarks in color images is proposed. Through color gamut analysis and quantizer design, color watermarks are embedded by modifying quantization indices of color pixels without resulting in perceivable distortion. Only a small amount of information including the specification of color gamut, quantizer stepsize, and color tables is required to extract the watermark. Experimental results show that the proposed watermarking scheme is computationally simple and quite robust in face of various attacks such as cropping, low-pass filtering, white-noise addition, scaling, and JPEG compression with high compression ratios.

Electron beam induced coloration and luminescence in layered structure of WO3 thin films grown by pulsed dc magnetron sputtering

International Nuclear Information System (INIS)

Karuppasamy, A.; Subrahmanyam, A.

2007-01-01

Tungsten oxide thin films have been deposited by pulsed dc magnetron sputtering of tungsten in argon and oxygen atmosphere. The as-deposited WO 3 film is amorphous, highly transparent, and shows a layered structure along the edges. In addition, the optical properties of the as-deposited film show a steplike behavior of extinction coefficient. However, the electron beam irradiation (3.0 keV) of the as-deposited films results in crystallization, coloration (deep blue), and luminescence (intense red emission). The above changes in physical properties are attributed to the extraction of oxygen atoms from the sample and the structural modifications induced by electron bombardment. The present method of coloration and luminescence has a potential for fabricating high-density optical data storage device

Confocal fluorescence microscopy investigation of visible emitting defects induced by electron beam lithography in LIF films

International Nuclear Information System (INIS)

Montereali, R. M.; Bigotta, S.; Pace, A.; Piccinini, M.; Burattini, E.; Grilli, A.; Raco, A.; Giammatteo, M.; L'Aquila Univ., L'Aquila; Picozzi, P.; Santucci, S.; L'Aquila Univ., L'Aquila

2000-01-01

Low energy electron irradiation of lithium fluoride (LiF), in the form of bulk crystals and films, gives rise to the stable formation of primary F defects and aggregated color centers in a thin layer located at the surface of the investigated material. For the first time a confocal light scanning microscope (CLSM) in fluorescence mode was used to reconstruct the depth distribution of efficiently emitting laser active color centers in a stripe-like region induced by 12 and 16 keV electrons on LiF films thermally evaporated on glass. The formation of the F3+ and F2 aggregated defects appears restricted to the electron penetration and proportional to their energy depth profile, as obtained from Monte Carlo simulations [it

Neutron Electric Dipole Moment from colored scalars⋆

Directory of Open Access Journals (Sweden)

Fajfer Svjetlana

2014-01-01

Full Text Available We present new contributions to the neutron electric dipole moment induced by a color octet, weak doublet scalar, accommodated within a modified Minimal Flavor Violating framework. These flavor non-diagonal couplings of the color octet scalar might account for an assymmetry of order 3 × 10−3 for aCP(D0 → K−K+ − aCP(D0 → π+π− at tree level. The same couplings constrained by this assymmetry also induce two-loop contributions to the neutron electric dipole moment. We find that the direct CP violating asymmetry in neutral D-meson decays is more constraining on the allowed parameter space than the current experimental bound on neutron electric dipole moment.

Color evaluation of computer-generated color rainbow holography

International Nuclear Information System (INIS)

Shi, Yile; Wang, Hui; Wu, Qiong

2013-01-01

A color evaluation approach for computer-generated color rainbow holography (CGCRH) is presented. Firstly, the relationship between color quantities of a computer display and a color computer-generated holography (CCGH) colorimetric system is discussed based on color matching theory. An isochromatic transfer relationship of color quantity and amplitude of object light field is proposed. Secondly, the color reproduction mechanism and factors leading to the color difference between the color object and the holographic image that is reconstructed by CGCRH are analyzed in detail. A quantitative color calculation method for the holographic image reconstructed by CGCRH is given. Finally, general color samples are selected as numerical calculation test targets and the color differences between holographic images and test targets are calculated based on our proposed method. (paper)

Plasmonic laser printing for ink-free color decoration

DEFF Research Database (Denmark)

Zhu, Xiaolong; Vannahme, Christoph; Højlund-Nielsen, Emil

2016-01-01

Here we show a method of color printing on nanoimprinted plasmonic metasurfaces [1] using laser post-writing. Laser pulses induce transient local heat generation that leads to melting and reshaping of the imprinted nanostructures [2]. This leads to melting and reshaping of the imprinted 20nm Al...... also be used on a larger scale to personify products such as mobile phones with unique decorations, names, etc‥ This laser technology may create environmentally sound color printing solutions and simplify the production for consumer products....... structures embedded in plastics. Depending on the laser pulse energy density, different surface morphologies that support different plasmonic resonances leading to different color appearances can be created. Color printing by this technology has several advantages over dye technology: ink/toner-free, sub...

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.

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.

Coloring of synthetic fluorite

International Nuclear Information System (INIS)

Birsoy, R.

1980-01-01

A synthetic fluorite of the Harshaw Chemical Company is analyzed for rare earth elements, yttrium, and sodium. Samples of this fluorite are irradiated with X-rays, γ-rays, neutrons, electrons, protons, and α-particles at different energies, and their absorption spectra are analyzed. Analyzing the thermal bleaching of these radiation-coloured fluorites shows that both, impurities and radiation play a part in the coloration of synthetic fluorite. However, the main contribution comes from the radiation induced lattice defects. In the visible region spectra, the colour centre of the 5800 to 5900 A absorption band is probably mainly related with large aggregates of F-centres. The 5450 and the 5300 A absorption bands are mainly related to monovalent and divalent ion impurities and their association with lattice defects. The 3800 A absorption band seems to be related with F-centre aggregates. However, the contribution from the rare earth elements related complex color centres also plays some part for the production of this absorption band. These results indicate that the color centres of different origin can absorb light at the same wavelength. (author)

Synesthetic colors are elicited by sound quality in Japanese synesthetes.

Science.gov (United States)

Asano, Michiko; Yokosawa, Kazuhiko

2011-12-01

Determinants of synesthetic color choice for Japanese phonetic characters were studied in six Japanese synesthetes. The study used Hiragana and Katakana characters, which represent the same set of syllables although their visual forms are dissimilar. From a palette of 138 colors, synesthetes selected a color corresponding to each character. Results revealed that synesthetic color choices for Hiragana characters and those for their Katakana counterparts were remarkably consistent, indicating that color selection depended on character-related sounds and not visual form. This Hiragana-Katakana invariance cannot be regarded as the same phenomenon as letter case invariance, usually reported for English grapheme-color synesthesia, because Hiragana and Katakana characters have different identities whereas upper and lower case letters have the same identity. This involvement of phonology suggests that cross-activation between an inducer (i.e., letter/character) brain region and that of the concurrent (i.e., color) area in grapheme-color synesthesia is mediated by higher order cortical processing areas. Copyright © 2011 Elsevier Inc. All rights reserved.

Homeostatic study of the effects of sportswear color on the contest outcome

Science.gov (United States)

Yuan, Jian-Qin; Liu, Timon Cheng-Yi; Wu, Ren-Le; Ruan, Chang-Xiong; He, Li-Mei; Liu, Song-Hao

2008-12-01

There are effects of sportswear color on the contest outcome. It has been explained from the psychological and perceptual viewpoints, respectively. It was studied by integrating the homeostatic theory of exercise training and autonomic nervous model of color vision in this paper. It was found that the effects of sportswear color on the contest outcome depend on autonomic nervous homeostasis (ANH). Color can be classified into hot color such as red, orange and yellow and cold color such as green, blue and violet. If the athletes have been in ANH, there are no effects of sportswear color on the contest outcome. If the autonomic nervous system is far from ANH due to exercise induced fatigue, wearing cold color had no predominance for cold-hot matches, and wearing white had no predominance for white-color matches.

F center deexcitation induced by local vibration tunneling

International Nuclear Information System (INIS)

Gomes, L.; Morato, S.P.

1990-01-01

A new concept of electronic deexcitation of defects has been made for systems where the electron couples very strong with a local lattice mode. The model is based on a classical - quantum description of the configuration curve diagram which proposes that an electronic transition may be induced when the wave packets of both oscillators involved are overlaping. It was successfully applied to the F center system, at low temperatures, in almost all the alkali halides. The luminescence efficiency derived from the model explains very well the observation, even the fact that the F * - electron always reaches the relaxed excited state. (author) [pt

Creation and characterization of He-related color centers in diamond

Energy Technology Data Exchange (ETDEWEB)

Forneris, J., E-mail: forneris@to.infn.it [Istituto Nazionale di Fisica Nucleare (INFN), Sez. Torino, via P. Giuria 1, 10125 Torino (Italy); Physics Department and “NIS” Inter-departmental Centre - University of Torino, 10125 Torino (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Sez. Torino, Torino (Italy); Tengattini, A.; Tchernij, S. Ditalia [Physics Department and “NIS” Inter-departmental Centre - University of Torino, 10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sez. Torino, via P. Giuria 1, 10125 Torino (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Sez. Torino, Torino (Italy); Picollo, F. [Istituto Nazionale di Fisica Nucleare (INFN), Sez. Torino, via P. Giuria 1, 10125 Torino (Italy); Physics Department and “NIS” Inter-departmental Centre - University of Torino, 10125 Torino (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Sez. Torino, Torino (Italy); Battiato, A. [Physics Department and “NIS” Inter-departmental Centre - University of Torino, 10125 Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sez. Torino, via P. Giuria 1, 10125 Torino (Italy); Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia (CNISM), Sez. Torino, Torino (Italy); Traina, P.; Degiovanni, I.P.; Moreva, E.; Brida, G. [Istituto Nazionale di Ricerca Metrologica (INRiM), Strada delle Cacce 91, 10135 Torino (Italy); Grilj, V.; Skukan, N.; Jakšić, M. [Ruđer Bošković Institute, Bijenicka 54, P.O. Box 180, 10002 Zagreb (Croatia); and others

2016-11-15

Diamond is a promising material for the development of emerging applications in quantum optics, quantum information and quantum sensing. The fabrication and characterization of novel luminescent defects with suitable opto-physical properties is therefore of primary importance for further advances in these research fields. In this work we report on the investigation in the formation of photoluminescent (PL) defects upon MeV He implantation in diamond. Such color centers, previously reported only in electroluminescence and cathodoluminescence regime, exhibited two sharp emission lines at 536.5 nm and 560.5 nm, without significant phonon sidebands. A strong correlation between the PL intensities of the above-mentioned emission lines and the He implantation fluence was found in the 10{sup 15}–10{sup 17} cm{sup −2} fluence range. The PL emission features were not detected in control samples, i.e. samples that were either unirradiated or irradiated with different ion species (H, C). Therefore, the PL features are attributed to optically active defects in the diamond matrix associated with He impurities. The intensity of the 536.5 nm and 560.5 nm emission lines was investigated as a function of the annealing temperature of the diamond substrate. The emission was observed upon annealing at temperatures higher than 500 °C, at the expenses of the concurrently decreasing neutral-vacancy-related GR1 emission intensity. Therefore, our findings indicate that the luminescence originates from the formation of a stable lattice defect. Finally, photoluminescence from He-related defects was observed under different laser excitations wavelengths (i.e. 532 nm and 405 nm), thus providing promising evidence of a broad spectral range for optical stimulation. - Highlights: • Creation of luminescent defects in single-crystal diamond upon He implantation. • First observation of photoluminescent emission from two sharp emission lines at 536.5 and 560.5 nm. • Attribution of the

Creation and characterization of He-related color centers in diamond

International Nuclear Information System (INIS)

Forneris, J.; Tengattini, A.; Tchernij, S. Ditalia; Picollo, F.; Battiato, A.; Traina, P.; Degiovanni, I.P.; Moreva, E.; Brida, G.; Grilj, V.; Skukan, N.; Jakšić, M.

2016-01-01

Diamond is a promising material for the development of emerging applications in quantum optics, quantum information and quantum sensing. The fabrication and characterization of novel luminescent defects with suitable opto-physical properties is therefore of primary importance for further advances in these research fields. In this work we report on the investigation in the formation of photoluminescent (PL) defects upon MeV He implantation in diamond. Such color centers, previously reported only in electroluminescence and cathodoluminescence regime, exhibited two sharp emission lines at 536.5 nm and 560.5 nm, without significant phonon sidebands. A strong correlation between the PL intensities of the above-mentioned emission lines and the He implantation fluence was found in the 10 15 –10 17 cm −2 fluence range. The PL emission features were not detected in control samples, i.e. samples that were either unirradiated or irradiated with different ion species (H, C). Therefore, the PL features are attributed to optically active defects in the diamond matrix associated with He impurities. The intensity of the 536.5 nm and 560.5 nm emission lines was investigated as a function of the annealing temperature of the diamond substrate. The emission was observed upon annealing at temperatures higher than 500 °C, at the expenses of the concurrently decreasing neutral-vacancy-related GR1 emission intensity. Therefore, our findings indicate that the luminescence originates from the formation of a stable lattice defect. Finally, photoluminescence from He-related defects was observed under different laser excitations wavelengths (i.e. 532 nm and 405 nm), thus providing promising evidence of a broad spectral range for optical stimulation. - Highlights: • Creation of luminescent defects in single-crystal diamond upon He implantation. • First observation of photoluminescent emission from two sharp emission lines at 536.5 and 560.5 nm. • Attribution of the emission lines to

Colorization-Based RGB-White Color Interpolation using Color Filter Array with Randomly Sampled Pattern.

Science.gov (United States)

Oh, Paul; Lee, Sukho; Kang, Moon Gi

2017-06-28

Recently, several RGB-White (RGBW) color filter arrays (CFAs) have been proposed, which have extra white (W) pixels in the filter array that are highly sensitive. Due to the high sensitivity, the W pixels have better SNR (Signal to Noise Ratio) characteristics than other color pixels in the filter array, especially, in low light conditions. However, most of the RGBW CFAs are designed so that the acquired RGBW pattern image can be converted into the conventional Bayer pattern image, which is then again converted into the final color image by using conventional demosaicing methods, i.e., color interpolation techniques. In this paper, we propose a new RGBW color filter array based on a totally different color interpolation technique, the colorization algorithm. The colorization algorithm was initially proposed for colorizing a gray image into a color image using a small number of color seeds. Here, we adopt this algorithm as a color interpolation technique, so that the RGBW color filter array can be designed with a very large number of W pixels to make the most of the highly sensitive characteristics of the W channel. The resulting RGBW color filter array has a pattern with a large proportion of W pixels, while the small-numbered RGB pixels are randomly distributed over the array. The colorization algorithm makes it possible to reconstruct the colors from such a small number of RGB values. Due to the large proportion of W pixels, the reconstructed color image has a high SNR value, especially higher than those of conventional CFAs in low light condition. Experimental results show that many important information which are not perceived in color images reconstructed with conventional CFAs are perceived in the images reconstructed with the proposed method.

Enhanced dimension-specific visual working memory in grapheme-color synesthesia.

Science.gov (United States)

Terhune, Devin Blair; Wudarczyk, Olga Anna; Kochuparampil, Priya; Cohen Kadosh, Roi

2013-10-01

There is emerging evidence that the encoding of visual information and the maintenance of this information in a temporarily accessible state in working memory rely on the same neural mechanisms. A consequence of this overlap is that atypical forms of perception should influence working memory. We examined this by investigating whether having grapheme-color synesthesia, a condition characterized by the involuntary experience of color photisms when reading or representing graphemes, would confer benefits on working memory. Two competing hypotheses propose that superior memory in synesthesia results from information being coded in two information channels (dual-coding) or from superior dimension-specific visual processing (enhanced processing). We discriminated between these hypotheses in three n-back experiments in which controls and synesthetes viewed inducer and non-inducer graphemes and maintained color or grapheme information in working memory. Synesthetes displayed superior color working memory than controls for both grapheme types, whereas the two groups did not differ in grapheme working memory. Further analyses excluded the possibilities of enhanced working memory among synesthetes being due to greater color discrimination, stimulus color familiarity, or bidirectionality. These results reveal enhanced dimension-specific visual working memory in this population and supply further evidence for a close relationship between sensory processing and the maintenance of sensory information in working memory. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Of colored numbers and numbered colors: interactive processes in grapheme-color synesthesia.

Science.gov (United States)

Gebuis, Titia; Nijboer, Tanja C W; van der Smagt, Maarten J

2009-01-01

Grapheme-color synesthetes experience a specific color when they see a grapheme but they do not report to perceive a grapheme when a color is presented. In this study, we investigate whether color can still evoke number-processes even when a vivid number experience is absent. We used color-number and number-color priming, both revealing faster responses in congruent compared to incongruent conditions. Interestingly, the congruency effect was of similar magnitude for both conditions, and a numerical distance effect was present only in the color-number priming task. In addition, a priming task in which synesthetes had to judge the parity of a colored number revealed faster responses in parity congruent than in parity incongruent trials. These combined results demonstrate that synesthesia is indeed bi-directional and of similar strength in both directions. Furthermore, they illustrate the precise nature of these interactions and show that the direction of these interactions is determined by task demands, not by the more vividly experienced aspect of the stimulus.

Cortical Activation during Landmark-Centered vs. Gaze-Centered Memory of Saccade Targets in the Human: An FMRI Study

Directory of Open Access Journals (Sweden)

Ying Chen

2017-06-01

Full Text Available A remembered saccade target could be encoded in egocentric coordinates such as gaze-centered, or relative to some external allocentric landmark that is independent of the target or gaze (landmark-centered. In comparison to egocentric mechanisms, very little is known about such a landmark-centered representation. Here, we used an event-related fMRI design to identify brain areas supporting these two types of spatial coding (i.e., landmark-centered vs. gaze-centered for target memory during the Delay phase where only target location, not saccade direction, was specified. The paradigm included three tasks with identical display of visual stimuli but different auditory instructions: Landmark Saccade (remember target location relative to a visual landmark, independent of gaze, Control Saccade (remember original target location relative to gaze fixation, independent of the landmark, and a non-spatial control, Color Report (report target color. During the Delay phase, the Control and Landmark Saccade tasks activated overlapping areas in posterior parietal cortex (PPC and frontal cortex as compared to the color control, but with higher activation in PPC for target coding in the Control Saccade task and higher activation in temporal and occipital cortex for target coding in Landmark Saccade task. Gaze-centered directional selectivity was observed in superior occipital gyrus and inferior occipital gyrus, whereas landmark-centered directional selectivity was observed in precuneus and midposterior intraparietal sulcus. During the Response phase after saccade direction was specified, the parietofrontal network in the left hemisphere showed higher activation for rightward than leftward saccades. Our results suggest that cortical activation for coding saccade target direction relative to a visual landmark differs from gaze-centered directional selectivity for target memory, from the mechanisms for other types of allocentric tasks, and from the directionally

Failure to replicate the Mehta and Zhu (2009) color-priming effect on anagram solution times.

Science.gov (United States)

Steele, Kenneth M

2014-06-01

Mehta and Zhu (Science, 323, 1226-1229, 2009) hypothesized that the color red induces avoidance motivation and that the color blue induces approach motivation. In one experiment, they reported that anagrams of avoidance motivation words were solved more quickly on red backgrounds and that approach motivation anagrams were solved more quickly on blue backgrounds. Reported here is a direct replication of that experiment, using the same anagrams, instructions, and colors, with more than triple the number of participants used in the original study. The results did not show the Mehta and Zhu color-priming effects, even though statistical power was sufficient to detect the effect. The results call into question the existence of their color-priming effect on the solution of anagrams.

Colored noise and memory effects on formal spiking neuron models

Science.gov (United States)

da Silva, L. A.; Vilela, R. D.

2015-06-01

Simplified neuronal models capture the essence of the electrical activity of a generic neuron, besides being more interesting from the computational point of view when compared to higher-dimensional models such as the Hodgkin-Huxley one. In this work, we propose a generalized resonate-and-fire model described by a generalized Langevin equation that takes into account memory effects and colored noise. We perform a comprehensive numerical analysis to study the dynamics and the point process statistics of the proposed model, highlighting interesting new features such as (i) nonmonotonic behavior (emergence of peak structures, enhanced by the choice of colored noise characteristic time scale) of the coefficient of variation (CV) as a function of memory characteristic time scale, (ii) colored noise-induced shift in the CV, and (iii) emergence and suppression of multimodality in the interspike interval (ISI) distribution due to memory-induced subthreshold oscillations. Moreover, in the noise-induced spike regime, we study how memory and colored noise affect the coherence resonance (CR) phenomenon. We found that for sufficiently long memory, not only is CR suppressed but also the minimum of the CV-versus-noise intensity curve that characterizes the presence of CR may be replaced by a maximum. The aforementioned features allow to interpret the interplay between memory and colored noise as an effective control mechanism to neuronal variability. Since both variability and nontrivial temporal patterns in the ISI distribution are ubiquitous in biological cells, we hope the present model can be useful in modeling real aspects of neurons.

The number of k-colorings of a graph on a fixed surface

DEFF Research Database (Denmark)

Thomassen, Carsten

2006-01-01

We prove that, for every fixed surface S, there exists a largest positive constant c such that every 5-colorable graph with n vertices on S has at least c center dot 2(n) distinct 5-colorings. This is best possible in the sense that, for each sufficiently large natural number n, there is a graph ...

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.

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…

Visual color matching system based on RGB LED light source

Science.gov (United States)

Sun, Lei; Huang, Qingmei; Feng, Chen; Li, Wei; Wang, Chaofeng

2018-01-01

In order to study the property and performance of LED as RGB primary color light sources on color mixture in visual psychophysical experiments, and to find out the difference between LED light source and traditional light source, a visual color matching experiment system based on LED light sources as RGB primary colors has been built. By simulating traditional experiment of metameric color matching in CIE 1931 RGB color system, it can be used for visual color matching experiments to obtain a set of the spectral tristimulus values which we often call color-matching functions (CMFs). This system consists of three parts: a monochromatic light part using blazed grating, a light mixing part where the summation of 3 LED illuminations are to be visually matched with a monochromatic illumination, and a visual observation part. The three narrow band LEDs used have dominant wavelengths of 640 nm (red), 522 nm (green) and 458 nm (blue) respectively and their intensities can be controlled independently. After the calibration of wavelength and luminance of LED sources with a spectrophotometer, a series of visual color matching experiments have been carried out by 5 observers. The results are compared with those from CIE 1931 RGB color system, and have been used to compute an average locus for the spectral colors in the color triangle, with white at the center. It has been shown that the use of LED is feasible and has the advantages of easy control, good stability and low cost.

How do we select multiple features? Transient costs for selecting two colors rather than one, persistent costs for color-location conjunctions.

Science.gov (United States)

Lo, Shih-Yu; Holcombe, Alex O

2014-02-01

In a previous study Lo, Howard, & Holcombe (Vision Research 63:20-33, 2012), selecting two colors did not induce a performance cost, relative to selecting one color. For example, requiring possible report of both a green and a red target did not yield a worse performance than when both targets were green. Yet a cost of selecting multiple colors was observed when selection needed be contingent on both color and location. When selecting a red target to the left and a green target to the right, superimposing a green distractor to the left and a red distractor to the right impeded performance. Possibly, participants cannot confine attention to a color at a particular location. As a result, distractors that share the target colors disrupt attentional selection of the targets. The attempt to select the targets must then be repeated, which increases the likelihood that the trial terminates when selection is not effective, even for long trials. Consistent with this, here we find a persistent cost of selecting two colors when the conjunction of color and location is needed, but the cost is confined to short exposure durations when the observer just has to monitor red and green stimuli without the need to use the location information. These results suggest that selecting two colors is time-consuming but effective, whereas selection of simultaneous conjunctions is never entirely successful.

Color Categories and Color Appearance

Science.gov (United States)

Webster, Michael A.; Kay, Paul

2012-01-01

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…

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…

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.

Twin edge colorings of certain square graphs and product graphs

Directory of Open Access Journals (Sweden)

R Rajarajachozhan

2016-04-01

Full Text Available A twin edge $k\\!$-coloring of a graph $G$ is a proper edge $k$-coloring of $G$ with the elements of $\\mathbb{Z}_k$ so that the induced vertex $k$-coloring, in which the color of a vertex $v$ in $G$ is the sum in $\\mathbb{Z}_k$ of the colors of the edges incident with $v,$ is a proper vertex $k\\!$-coloring. The minimum $k$ for which $G$ has a twin edge $k\\!$-coloring is called the twin chromatic index of $G.$ Twin chromatic index of the square $P_n^2,$ $n\\ge 4,$ and the square $C_n^2,$ $n\\ge 6,$ are determined. In fact, the twin chromatic index of the square $C_7^2$ is $\\Delta+2,$ where $\\Delta$ is the maximum degree. Twin chromatic index of $C_m\\,\\Box\\,P_n$ is determined, where $\\Box$ denotes the Cartesian product. $C_r$ and $P_r$ are, respectively, the cycle, and the path on $r$ vertices each.

Effects of Colored Noise on Periodic Orbits in a One-Dimensional Map

Science.gov (United States)

Li, Feng-Guo; Ai, Bao-Quan

2011-06-01

Noise can induce inverse period-doubling transition and chaos. The effects of the colored noise on periodic orbits, of the different periodic sequences in the logistic map, are investigated. It is found that the dynamical behaviors of the orbits, induced by an exponentially correlated colored noise, are different in the mergence of transition, and the effects of the noise intensity on their dynamical behaviors are different from the effects of the correlation time of noise. Remarkably, the noise can induce new periodic orbits, namely, two new orbits emerge in the period-four sequence at the bifurcation parameter value μ = 3.5, four new orbits in the period-eight sequence at μ = 3.55, and three new orbits in the period-six sequence at μ = 3.846, respectively. Moreover, the dynamical behaviors of the new orbits clearly show the resonancelike response to the colored noise.

Effects of Colored Noise on Periodic Orbits in a One-Dimensional Map

International Nuclear Information System (INIS)

Li Fengguo; Ai Baoquan

2011-01-01

Noise can induce inverse period-doubling transition and chaos. The effects of the colored noise on periodic orbits, of the different periodic sequences in the logistic map, are investigated. It is found that the dynamical behaviors of the orbits, induced by an exponentially correlated colored noise, are different in the mergence of transition, and the effects of the noise intensity on their dynamical behaviors are different from the effects of the correlation time of noise. Remarkably, the noise can induce new periodic orbits, namely, two new orbits emerge in the period-four sequence at the bifurcation parameter value μ = 3.5, four new orbits in the period-eight sequence at μ = 3.55, and three new orbits in the period-six sequence at μ = 3.846, respectively. Moreover, the dynamical behaviors of the new orbits clearly show the resonancelike response to the colored noise. (general)

Color change of gemstones by exposure to gamma rays

Energy Technology Data Exchange (ETDEWEB)

Lima, Giovanna L.C. de; Lameiras, Fernando S., E-mail: giovannalarissa17@hotmail.com, E-mail: fsl@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2015-07-01

A gem is appreciated by collectors and, when polished, widely used for jewelry manufacturing. For example, when quartz naturally or artificially acquires a color it becomes a gemstone (smoky quartz, morion, citrine, amethyst, or prasyolite). The presence of chromophore elements in a quartz sample was analysed by Fourier transform infrared spectrometry (FTIR). With a semi-quantitative analysis of the absorption FTIR spectra, it was possible to predict if colorless quartz has the potential to develop color when exposed to ionizing radiation and heat. Specific absorption bands show the presence of chromophore elements in quartz such as aluminum, iron, hydrogen, sodium, or lithium. Considering the ratio of the heights of the absorption bands of these elements, it was possible to predict the color quartz can develop. Samples of irradiated dark and light violet fluorites were analyzed by FTIR and energy-dispersive X-rays spectroscopy. The light violet samples has higher content of calcium relative to fluorine, as well higher content of hydroxyl, probably replacing fluorine in crystal lattice. Hydroxyls cannot be precursors of F color centers, which are the cause of violet color in fluorite, explaining the light violet color of hydroxyl-rich samples. (author)

Color change of gemstones by exposure to gamma rays

International Nuclear Information System (INIS)

Lima, Giovanna L.C. de; Lameiras, Fernando S.

2015-01-01

A gem is appreciated by collectors and, when polished, widely used for jewelry manufacturing. For example, when quartz naturally or artificially acquires a color it becomes a gemstone (smoky quartz, morion, citrine, amethyst, or prasyolite). The presence of chromophore elements in a quartz sample was analysed by Fourier transform infrared spectrometry (FTIR). With a semi-quantitative analysis of the absorption FTIR spectra, it was possible to predict if colorless quartz has the potential to develop color when exposed to ionizing radiation and heat. Specific absorption bands show the presence of chromophore elements in quartz such as aluminum, iron, hydrogen, sodium, or lithium. Considering the ratio of the heights of the absorption bands of these elements, it was possible to predict the color quartz can develop. Samples of irradiated dark and light violet fluorites were analyzed by FTIR and energy-dispersive X-rays spectroscopy. The light violet samples has higher content of calcium relative to fluorine, as well higher content of hydroxyl, probably replacing fluorine in crystal lattice. Hydroxyls cannot be precursors of F color centers, which are the cause of violet color in fluorite, explaining the light violet color of hydroxyl-rich samples. (author)

[Associative Learning between Orientation and Color in Early Visual Areas].

Science.gov (United States)

Amano, Kaoru; Shibata, Kazuhisa; Kawato, Mitsuo; Sasaki, Yuka; Watanabe, Takeo

2017-08-01

Associative learning is an essential neural phenomenon where the contingency of different items increases after training. Although associative learning has been found to occur in many brain regions, there is no clear evidence that associative learning of visual features occurs in early visual areas. Here, we developed an associative decoded functional magnetic resonance imaging (fMRI) neurofeedback (A-DecNef) to determine whether associative learning of color and orientation can be induced in early visual areas. During the three days' training, A-DecNef induced fMRI signal patterns that corresponded to a specific target color (red) mostly in early visual areas while a vertical achromatic grating was simultaneously, physically presented to participants. Consequently, participants' perception of "red" was significantly more frequently than that of "green" in an achromatic vertical grating. This effect was also observed 3 to 5 months after training. These results suggest that long-term associative learning of two different visual features such as color and orientation, was induced most likely in early visual areas. This newly extended technique that induces associative learning may be used as an important tool for understanding and modifying brain function, since associations are fundamental and ubiquitous with respect to brain function.

Heat-induced chemical and color changes of extractive-free Black Locust (Rosinia Pseudoacacia) wood

Science.gov (United States)

Yao Chen; Jianmin Gao; Yongming Fan; Mandla A. Tshabalala; Nicole M. Stark

2012-01-01

To investigate chemical and color changes of the polymeric constituents of black locust (Robinia pseudoacacia) wood during heat treatment, extractive-free wood flour was conditioned to 30% initial moisture content (MC) and heated for 24 h at 120 °C in either an oxygen or nitrogen atmosphere. The color change was measured using the CIELAB color system. Chemical changes...

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.

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…

Luminance contours can gate afterimage colors and "real" colors.

Science.gov (United States)

Anstis, Stuart; Vergeer, Mark; Van Lier, Rob

2012-09-06

It has long been known that colored images may elicit afterimages in complementary colors. We have already shown (Van Lier, Vergeer, & Anstis, 2009) that one and the same adapting image may result in different afterimage colors, depending on the test contours presented after the colored image. The color of the afterimage depends on two adapting colors, those both inside and outside the test. Here, we further explore this phenomenon and show that the color-contour interactions shown for afterimage colors also occur for "real" colors. We argue that similar mechanisms apply for both types of stimulation.

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

Postpartum unconscious dynamics emerging from the Lüscher color test in Ethiopian women.

Science.gov (United States)

Zanardo, Vincenzo; Gabrieli, Catia; Volpe, Francesca; Savio, Francesca; Straface, Gianluca; Soldera, Gino

2017-06-01

The aim of this study was to explore the feasibility of the Lüscher color test (LCT), a psychological instrument based on theory that colors are selected in unconscious way and that the color sensory perception of color is objective and universal. The research has involved 24 Ethiopian women, which delivered at the Getche Health Center in Gurage. It seemed to be relevant for the majority of Ethiopian women identify the rejected color (58.66%), the gray, than the favorite color, the yellow 33.33%). The yellow color suggests that they better express their personality in a physical context, while the gray color indicates that they want to live this experience intensely. This exploratory work lays the foundations for further studies in disadvantaged women, both in developing low-income Countries as well as in industrialized Countries characterized by an high level of emigration, and for clinical applications by the complete LCT version.

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.

Quantum manipulation of two-color stationary light: Quantum wavelength conversion

International Nuclear Information System (INIS)

Moiseev, S. A.; Ham, B. S.

2006-01-01

We present a quantum manipulation of a traveling light pulse using electromagnetically induced transparency-based slow light phenomenon for the generation of two-color stationary light. We theoretically discuss the two-color stationary light for the quantum wavelength conversion process in terms of pulse area, energy transfer, and propagation directions. The condition of the two-color stationary light pulse generation has been found and the quantum light dynamics has been studied analytically in the adiabatic limit. The quantum frequency conversion rate of the traveling light is dependent on the spatial spreading of the two-color stationary light pulse and can be near unity in an optically dense medium for the optimal frequencies of the control laser fields

Photodissociation comprehensive study of OH- on alkali halides and their interaction with colour centers

International Nuclear Information System (INIS)

Gomes, L.

1985-01-01

This work shows that the OH - defect induces changes in the electronics processes of the alkali halides such as in radiation damage and optical cycles of colour centers. Two cases were considered: with the presence of an OH - ion in the (1) excited state and (2) in the ground state; 1) the comprehensive study of resonant OH - photodissociation in several hosts showed that deep traps (for electrons) can be produced from the OH - dissociation. These traps can be effective for the capture of electrons produced in the radiation damage of the lattice as well as for trapping electrons from ionized color centers. It was observed a second channel (new) for the de-excitation of the (OH - )* molecule in KI and RbI. This effect can be effective only when the lattice around the molecule holds a large enough interstitial space. This new mechanism is responsible for the strong production at LNT of F centers and OH 0 molecules at the expenses of OH - defects. Considering the complete investigation of the full cycle it was proposed a phenomenological model that would explain the observed behaviour when one covers a wide variation of lattice parameters (KCl -> RbI); 2) It was verified that the OH - ion present in the lattice induces strong changes in the de-excitation processes of electronic defects with a spread out wave function (like F centers). A change in the reorientation behaviour of excited F 2 and F + 2 centers was also verified. Two main effects should be mentioned: A) The induced de-excitation is very fast and non-radiative on F centers. B) Another type of system investigated (F 2 and F + 2 ) has shown an intense increase of the speed of reorientation of the F 2 and F + 2 excited centers. (autor) [pt

Sharing Our Unheard Voices: Perceptions of the Lived Experience of Teachers of Color

Science.gov (United States)

Berrios, Darline

2016-01-01

In public education, approximately 80% of teachers in the United States are White, yet close to half of the student population are students of color (U.S. Department of Education, 2011). Gaps in teacher diversity compared with students of color are found in every state across the country (Center for American Progress, 2011). In 2004, the National…

Nonvolatile two-step, two-color holography with continuous-wave lights for both congruent and near-stoichiometric LiNbO3:Fe

International Nuclear Information System (INIS)

Shen Yan; Zhang Guoquan; Fu Bo; Xu Qingjun; Xu Jingjun

2004-01-01

We have studied theoretically the steady-state nonvolatile two-step, two-color holographic recording performance for both the congruent and the near-stoichiometric LiNbO 3 :Fe based on the two-center model (the deep-trap and the shallow-trap centers are Fe 2+ /Fe 3+ and Nb Li 4+ /Nb Li 5+ , respectively). The results show that the direct electron exchange between the Fe 2+ /Fe 3+ centers and the Nb Li 4+ /Nb Li 5+ centers due to the tunneling effect dominates the charge-transfer process during the nonvolatile two-step, two-color holography and determines the two-step, two-color holography performance in LiNbO 3 :Fe. We have further studied the effects of the crystal stoichiometry on the performance of the two-step, two-color holography. It is shown that, as far as the total space-charge field is considered, the nonvolatile two-step, two-color holography performance in the near-stoichiometric LiNbO 3 :Fe is much better than that in the congruent LiNbO 3 :Fe within the intensity range reachable by the continuous-wave lights

Shift Colors

Science.gov (United States)

Publications & News Shift Colors Pages default Sign In NPC Logo Banner : Shift Colors Search Navy Personnel Command > Reference Library > Publications & News > Shift Colors Top Link Bar Navy Personnel Library Expand Reference Library Quick Launch Shift Colors Shift Colors Archives Mailing Address How to

The lipid dependence of melittin action investigated by dual-color fluorescence burst analysis

NARCIS (Netherlands)

Bogaart, Geert van den; Mika, Jacek T.; Krasnikov, Viktor; Poolman, Bert

Dual-color fluorescence-burst analysis was used to study melittin-induced leakage of macromolecules from liposomes of various lipid compositions. To perform dual-color fluorescence-burst analysis, fluorescently labeled size-marker molecules were encapsulated into liposomes, labeled with a second

Natural Colorants: Food Colorants from Natural Sources.

Science.gov (United States)

Sigurdson, Gregory T; Tang, Peipei; Giusti, M Mónica

2017-02-28

The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

The Verriest Lecture: Color lessons from space, time, and motion

Science.gov (United States)

Shevell, Steven K.

2012-01-01

The appearance of a chromatic stimulus depends on more than the wavelengths composing it. The scientific literature has countless examples showing that spatial and temporal features of light influence the colors we see. Studying chromatic stimuli that vary over space, time or direction of motion has a further benefit beyond predicting color appearance: the unveiling of otherwise concealed neural processes of color vision. Spatial or temporal stimulus variation uncovers multiple mechanisms of brightness and color perception at distinct levels of the visual pathway. Spatial variation in chromaticity and luminance can change perceived three-dimensional shape, an example of chromatic signals that affect a percept other than color. Chromatic objects in motion expose the surprisingly weak link between the chromaticity of objects and their physical direction of motion, and the role of color in inducing an illusory motion direction. Space, time and motion – color’s colleagues – reveal the richness of chromatic neural processing. PMID:22330398

Light-induced dynamic structural color by intracellular 3D photonic crystals in brown algae.

Science.gov (United States)

Lopez-Garcia, Martin; Masters, Nathan; O'Brien, Heath E; Lennon, Joseph; Atkinson, George; Cryan, Martin J; Oulton, Ruth; Whitney, Heather M

2018-04-01

Natural photonic crystals are responsible for strong reflectance at selective wavelengths in different natural systems. We demonstrate that intracellular opal-like photonic crystals formed from lipids within photosynthetic cells produce vivid structural color in the alga Cystoseira tamariscifolia . The reflectance of the opaline vesicles is dynamically responsive to environmental illumination. The structural color is present in low light-adapted samples, whereas higher light levels produce a slow disappearance of the structural color such that it eventually vanishes completely. Once returned to low-light conditions, the color re-emerges. Our results suggest that these complex intracellular natural photonic crystals are responsive to environmental conditions, changing their packing structure reversibly, and have the potential to manipulate light for roles beyond visual signaling.

Colors, colored overlays, and reading skills

Directory of Open Access Journals (Sweden)

Arcangelo eUccula

2014-07-01

Full Text Available In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e. who experience eyestrain and/or visual distortions – e.g. color, shape or movement illusions – while reading. This condition would interest the 12-14% of the general population and up to the 46% of the dyslexic population. Thus, colored overlays have been largely employed as a remedy for some aspects of the difficulties in reading experienced by dyslexic individuals, as fluency and speed. Despite the wide use of colored overlays, how they exert their effects has not been made clear yet. Also, according to some researchers, the results supporting the efficacy of colored overlays as a tool for helping readers are at least controversial. Furthermore, the very nature of the Meares-Irlen syndrome has been questioned. Here we provide a concise, critical review of the literature.

Transcriptome analysis of the exocarp of apple fruit identifies light-induced genes involved in red color pigmentation.

Science.gov (United States)

Vimolmangkang, Sornkanok; Zheng, Danman; Han, Yuepeng; Khan, M Awais; Soria-Guerra, Ruth Elena; Korban, Schuyler S

2014-01-15

Although the mechanism of light regulation of color pigmentation of apple fruit is not fully understood, it has been shown that light can regulate expression of genes in the anthocyanin biosynthesis pathway by inducing transcription factors (TFs). Moreover, expression of genes encoding enzymes involved in this pathway may be coordinately regulated by multiple TFs. In this study, fruits on trees of apple cv. Red Delicious were covered with paper bags during early stages of fruit development and then removed prior to maturation to analyze the transcriptome in the exocarp of apple fruit. Comparisons of gene expression profiles of fruit covered with paper bags (dark-grown treatment) and those subjected to 14 h light treatment, following removal of paper bags, were investigated using an apple microarray of 40,000 sequences. Expression profiles were investigated over three time points, at one week intervals, during fruit development. Overall, 736 genes with expression values greater than two-fold were found to be modulated by light treatment. Light-induced products were classified into 19 categories with highest scores in primary metabolism (17%) and transcription (12%). Based on the Arabidopsis gene ontology annotation, 18 genes were identified as TFs. To further confirm expression patterns of flavonoid-related genes, these were subjected to quantitative RT-PCR (qRT-PCR) using fruit of red-skinned apple cv. Red Delicious and yellow-skinned apple cv. Golden Delicious. Of these, two genes showed higher levels of expression in 'Red Delicious' than in 'Golden Delicious', and were likely involved in the regulation of fruit red color pigmentation. © 2013 Elsevier B.V. All rights reserved.

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.

2012-01-01

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…

Pseudo-synesthesia through reading books with colored letters.

Directory of Open Access Journals (Sweden)

Olympia Colizoli

Full Text Available BACKGROUND: Synesthesia is a phenomenon where a stimulus produces consistent extraordinary subjective experiences. A relatively common type of synesthesia involves perception of color when viewing letters (e.g. the letter 'a' always appears as light blue. In this study, we examine whether traits typically regarded as markers of synesthesia can be acquired by simply reading in color. METHODOLOGY/PRINCIPAL FINDINGS: Non-synesthetes were given specially prepared colored books to read. A modified Stroop task was administered before and after reading. A perceptual crowding task was administered after reading. Reading one book (>49,000 words was sufficient to induce effects regarded as behavioral markers for synesthesia. The results of the Stroop tasks indicate that it is possible to learn letter-color associations through reading in color (F(1, 14 = 5.85, p = .030. Furthermore, Stroop effects correlated with subjective reports about experiencing letters in color (r(13 = 0.51, p = .05. The frequency of viewing letters is related to the level of association as seen by the difference in the Stroop effect size between upper- and lower-case letters (t(14 = 2.79, p = .014 and in a subgroup of participants whose Stroop effects increased as they continued to read in color. Readers did not show significant performance advantages on the crowding task compared to controls. Acknowledging the many differences between trainees and synesthetes, results suggest that it may be possible to acquire a subset of synesthetic behavioral traits in adulthood through training. CONCLUSION/SIGNIFICANCE: To our knowledge, this is the first evidence of acquiring letter-color associations through reading in color. Reading in color appears to be a promising avenue in which we may explore the differences and similarities between synesthetes and non-synesthetes. Additionally, reading in color is a plausible method for a long-term 'synesthetic' training program.

Color Analysis

Science.gov (United States)

Wrolstad, Ronald E.; Smith, Daniel E.

Color, flavor, and texture are the three principal quality attributes that determine food acceptance, and color has a far greater influence on our judgment than most of us appreciate. We use color to determine if a banana is at our preferred ripeness level, and a discolored meat product can warn us that the product may be spoiled. The marketing departments of our food corporations know that, for their customers, the color must be "right." The University of California Davis scorecard for wine quality designates four points out of 20, or 20% of the total score, for color and appearance (1). Food scientists who establish quality control specifications for their product are very aware of the importance of color and appearance. While subjective visual assessment and use of visual color standards are still used in the food industry, instrumental color measurements are extensively employed. Objective measurement of color is desirable for both research and industrial applications, and the ruggedness, stability, and ease of use of today's color measurement instruments have resulted in their widespread adoption.

Gamma coloration of mixed crystals of KCl-KBr doped with Pb2+

International Nuclear Information System (INIS)

Cruz Z, E.; Negron, A.; Ramos A, A.; Ramos B, S.; Hernandez A, J.; Jaque, F; Murrieta S, H.

2001-01-01

The amount of the first stage coloration in KCl 1-x Br x doped with Pb 2+ has been investigated as a function of the dose rate and impurity concentration. For a dose rate of 12.88 kGy/h, the F color center production was independent of the quantity of Pb 2+ , and varied according to the ratio KCl/KBr. At a proportion of 50% of each halogen the typical stages were observed. However, if the dose rate is less than 3.22 kGy/h, the coloration production depends on the quantity of Pb 2+ . (author)

Size-controlled fluorescent nanodiamonds: A facile method of fabrication and color-center counting

KAUST Repository

Mahfouz, Remi; Floyd, Daniel L.; Peng, Wei; Choy, Jennifer; Lončar, Marko; Bakr, Osman

2013-01-01

findings suggest that nanocrystal size separation by DGU may be used to control the number of defects per nanocrystal. The efficient approaches described herein to control and quantify DCCs are valuable to researchers as they explore applications for color

Coloration of chromium-doped yttrium aluminum garnet single-crystal fibers using a divalent codopant

International Nuclear Information System (INIS)

Tissue, B.M.; Jia, W.; Lu, L.; Yen, W.M.

1991-01-01

We have grown single-crystal fibers of Cr:YAG and Cr,Ca:YAG under oxidizing and reducing conditions by the laser-heated-pedestal-growth method. The Cr:YAG crystals were light green due to Cr 3+ in octahedral sites, while the Cr,Ca:YAG crystals were brown. The presence of the divalent codopant was the dominant factor determining the coloration in these single-crystal fibers, while the oxidizing power of the growth atmosphere had little effect on the coloration. The Cr,Ca:YAG had a broad absorption band centered at 1.03 μm and fluoresced from 1.1 to 1.7 μm, with a room-temperature lifetime of 3.5 μs. The presence of both chromium and a divalent codopant were necessary to create the optically-active center which produces the near-infrared emission. Doping with only Ca 2+ created a different coloration with absorption in the blue and ultraviolet. The coloration in the Cr,Ca:YAG is attributed to Cr 4+ and is produced in as-grown crystals without irradiation or annealing, as has been necessary in previous work

Color Memory

OpenAIRE

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

2017-01-01

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 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.

Photochemistry and reactions of OH- defects and F centers in alkali halides

International Nuclear Information System (INIS)

Morato, S.P.; Luety, F.

1978-01-01

Aditively colored KCl:OH - crystals showed under a combined UV and VIS irradiation, a nearly complete and irreversible destruction of all F centers and visible absorption in the crystal. Only upon heating the crystal above 650 0 C the F center coloration becomes partially restored. The photodissociation of the OH - (under UV light) together with the photoionization of the F center (under VIS light) produces a not effects where all the F centers are converted into U centers. These photoreactions produces high contrast visible images that are completely stable under light at RT. Besides the optical information storage aspect of this effect these photoreaction s can also be used for controlled production of Usub(A) centers if the crystal also contains a foreign metallic impurity such a Na + ion [pt

Color Algebras

Science.gov (United States)

Mulligan, Jeffrey B.

2017-01-01

A color algebra refers to a system for computing sums and products of colors, analogous to additive and subtractive color mixtures. The difficulty addressed here is the fact that, because of metamerism, we cannot know with certainty the spectrum that produced a particular color solely on the basis of sensory data. Knowledge of the spectrum is not required to compute additive mixture of colors, but is critical for subtractive (multiplicative) mixture. Therefore, we cannot predict with certainty the multiplicative interactions between colors based solely on sensory data. There are two potential applications of a color algebra: first, to aid modeling phenomena of human visual perception, such as color constancy and transparency; and, second, to provide better models of the interactions of lights and surfaces for computer graphics rendering.

Opponent-Color Fusion of Multi-Sensor Imagery: Visible, IR and SAR

National Research Council Canada - National Science Library

Waxman, A

1998-01-01

.... Building on the work reported in two of our earlier papers from IRIS Passive Sensors 1996, we show how opponent-color processing and center-surround shunting neural networks can be used to develop...

Color-Blind Racism, Color-Blind Theology, and Church Practices

Science.gov (United States)

Hearn, Mark

2009-01-01

Color-blind racism develops when persons ignore color in people and see them simply as individuals. As persons of color in racialized societies such as the United States are unequally treated on account of their color, the issue becomes a matter of faith and religious experience as religious leaders and educators, who disregard color, overlook…

Onset of color decoherence for soft gluon radiation in a medium

Science.gov (United States)

Mehtar-Tani, Y.; Salgado, C. A.; Tywoniuk, K.

2011-12-01

We report on recent studies of the phenomenon of color decoherence in jets in QCD media. The effect is most clearly observed in the radiation pattern of a quark-antiquark antenna, created in the same quantum state, traversing a dense color deconfined plasma. Multiple scattering with the medium color charges gradually destroys the coherence of the antenna. In the limit of opaque media, this ultimately leads to independent radiation off the antenna constituents. Accordingly, radiation off the total charge vanishes implying a memory loss effect induced by the medium.

Color impact in visual attention deployment considering emotional images

Science.gov (United States)

Chamaret, C.

2012-03-01

Color is a predominant factor in the human visual attention system. Even if it cannot be sufficient to the global or complete understanding of a scene, it may impact the visual attention deployment. We propose to study the color impact as well as the emotion aspect of pictures regarding the visual attention deployment. An eye-tracking campaign has been conducted involving twenty people watching half pictures of database in full color and the other half of database in grey color. The eye fixations of color and black and white images were highly correlated leading to the question of the integration of such cues in the design of visual attention model. Indeed, the prediction of two state-of-the-art computational models shows similar results for the two color categories. Similarly, the study of saccade amplitude and fixation duration versus time viewing did not bring any significant differences between the two mentioned categories. In addition, spatial coordinates of eye fixations reveal an interesting indicator for investigating the differences of visual attention deployment over time and fixation number. The second factor related to emotion categories shows evidences of emotional inter-categories differences between color and grey eye fixations for passive and positive emotion. The particular aspect associated to this category induces a specific behavior, rather based on high frequencies, where the color components influence the visual attention deployment.

Experimental Study on Color Durability of Color Asphalt Pavement

Science.gov (United States)

Ning, Shi; Huan, Su

2017-06-01

Aiming at the poor Color durability and the lack of research on Color asphalt pavement, spraying an anti-tire trace seal resin emulsion on the surface, a Color durable asphalt pavement was proposed. After long-term rolling and long-term aging test, the Color durability was evaluated by RGB function in Photoshop and trace residue rate formula. Test results proved that the Evaluation method was simple and effective. After long-term rolling, the Color of the road surface tends to a constant value. Spraying the emulsion on the road surface can resist tire traces. After long-term aging test, the resistance to tire traces was increased by 26.6% compared with the conventional type, while the former was 44.1% higher than the latter without long-term aging. The Color durable asphalt pavement can effectively improve the ability of Color asphalt pavement to resist tire traces, and significantly improve the Color durability of Color asphalt pavement.

A combined electrochemical-irradiation treatment of highly colored and polluted industrial wastewater

Energy Technology Data Exchange (ETDEWEB)

Barrera-Diaz, C. E-mail: cbarrera@uaemex.mx; Urena-Nunez, F. E-mail: fun@nuclear.inin.mx; Campos, E.; Palomar-Pardave, M. E-mail: mepp@correo.azc.uam.mx; Romero-Romo, M

2003-07-01

This study reports on the attainment of optimal conditions for two electrolytic methods to treat wastewater: namely, electrocoagulation and particle destabilization of a highly polluted industrial wastewater, and electrochemically induced oxidation induced by in situ generation of Fenton's reactive. Additionally, a combined method that consisted of electrochemical treatment plus {gamma}-irradiation was carried out. A typical composition of the industrial effluent treated was COD 3400 mg/l, color 3750 Pt/Co units, and fecal coliforms 21000 MPN/ml. The best removal efficiency was obtained with electrochemical oxidation induced in situ, that resulted in the reduction of 78% for the COD, 86% color and 99.9% fecal coliforms removal. A treatment sequence was designed and carried out, such that after both electrochemical processes, a {gamma}-irradiation technique was used to complete the procedure. The samples were irradiated with various doses in an ALC {gamma}-cell unit provided with a Co-60 source. The removal efficiency obtained was 95% for the COD values, 90% color and 99.9% for fecal coliforms.

A combined electrochemical-irradiation treatment of highly colored and polluted industrial wastewater

International Nuclear Information System (INIS)

Barrera-Diaz, C.; Urena-Nunez, F.; Campos, E.; Palomar-Pardave, M.; Romero-Romo, M.

2003-01-01

This study reports on the attainment of optimal conditions for two electrolytic methods to treat wastewater: namely, electrocoagulation and particle destabilization of a highly polluted industrial wastewater, and electrochemically induced oxidation induced by in situ generation of Fenton's reactive. Additionally, a combined method that consisted of electrochemical treatment plus γ-irradiation was carried out. A typical composition of the industrial effluent treated was COD 3400 mg/l, color 3750 Pt/Co units, and fecal coliforms 21000 MPN/ml. The best removal efficiency was obtained with electrochemical oxidation induced in situ, that resulted in the reduction of 78% for the COD, 86% color and 99.9% fecal coliforms removal. A treatment sequence was designed and carried out, such that after both electrochemical processes, a γ-irradiation technique was used to complete the procedure. The samples were irradiated with various doses in an ALC γ-cell unit provided with a Co-60 source. The removal efficiency obtained was 95% for the COD values, 90% color and 99.9% for fecal coliforms

A combined electrochemical-irradiation treatment of highly colored and polluted industrial wastewater

Science.gov (United States)

Barrera-Díaz, C.; Ureña-Nuñez, F.; Campos, E.; Palomar-Pardavé, M.; Romero-Romo, M.

2003-07-01

This study reports on the attainment of optimal conditions for two electrolytic methods to treat wastewater: namely, electrocoagulation and particle destabilization of a highly polluted industrial wastewater, and electrochemically induced oxidation induced by in situ generation of Fenton's reactive. Additionally, a combined method that consisted of electrochemical treatment plus γ-irradiation was carried out. A typical composition of the industrial effluent treated was COD 3400 mg/l, color 3750 Pt/Co units, and fecal coliforms 21000 MPN/ml. The best removal efficiency was obtained with electrochemical oxidation induced in situ , that resulted in the reduction of 78% for the COD, 86% color and 99.9% fecal coliforms removal. A treatment sequence was designed and carried out, such that after both electrochemical processes, a γ-irradiation technique was used to complete the procedure. The samples were irradiated with various doses in an ALC γ-cell unit provided with a Co-60 source. The removal efficiency obtained was 95% for the COD values, 90% color and 99.9% for fecal coliforms.

A Deep Learning Model of Perception in Color-Letter Synesthesia

Directory of Open Access Journals (Sweden)

Joel R. Bock

2018-03-01

Full Text Available Synesthesia is a psychological phenomenon where sensory signals become mixed. Input to one sensory modality produces an experience in a second, unstimulated modality. In “grapheme-color synesthesia”, viewed letters and numbers evoke mental imagery of colors. The study of this condition has implications for increasing our understanding of brain architecture and function, language, memory and semantics, and the nature of consciousness. In this work, we propose a novel application of deep learning to model perception in grapheme-color synesthesia. Achromatic letter images, taken from database of handwritten characters, are used to train the model, and to induce computational synesthesia. Results show the model learns to accurately create a colored version of the inducing stimulus, according to a statistical distribution from experiments on a sample population of grapheme-color synesthetes. To the author’s knowledge, this work represents the first model that accurately produces spontaneous, creative mental imagery characteristic of the synesthetic perceptual experience. Experiments in cognitive science have contributed to our understanding of some of the observable behavioral effects of synesthesia, and previous models have outlined neural mechanisms that may account for these observations. A model of synesthesia that generates testable predictions on brain activity and behavior is needed to complement large scale data collection efforts in neuroscience, especially when articulating simple descriptions of cause (stimulus and effect (behavior. The research and modeling approach reported here provides a framework that begins to address this need.

Color from hierarchy: Diverse optical properties of micron-sized spherical colloidal assemblies.

Science.gov (United States)

Vogel, Nicolas; Utech, Stefanie; England, Grant T; Shirman, Tanya; Phillips, Katherine R; Koay, Natalie; Burgess, Ian B; Kolle, Mathias; Weitz, David A; Aizenberg, Joanna

2015-09-01

Materials in nature are characterized by structural order over multiple length scales have evolved for maximum performance and multifunctionality, and are often produced by self-assembly processes. A striking example of this design principle is structural coloration, where interference, diffraction, and absorption effects result in vivid colors. Mimicking this emergence of complex effects from simple building blocks is a key challenge for man-made materials. Here, we show that a simple confined self-assembly process leads to a complex hierarchical geometry that displays a variety of optical effects. Colloidal crystallization in an emulsion droplet creates micron-sized superstructures, termed photonic balls. The curvature imposed by the emulsion droplet leads to frustrated crystallization. We observe spherical colloidal crystals with ordered, crystalline layers and a disordered core. This geometry produces multiple optical effects. The ordered layers give rise to structural color from Bragg diffraction with limited angular dependence and unusual transmission due to the curved nature of the individual crystals. The disordered core contributes nonresonant scattering that induces a macroscopically whitish appearance, which we mitigate by incorporating absorbing gold nanoparticles that suppress scattering and macroscopically purify the color. With increasing size of the constituent colloidal particles, grating diffraction effects dominate, which result from order along the crystal's curved surface and induce a vivid polychromatic appearance. The control of multiple optical effects induced by the hierarchical morphology in photonic balls paves the way to use them as building blocks for complex optical assemblies--potentially as more efficient mimics of structural color as it occurs in nature.

Color from hierarchy: Diverse optical properties of micron-sized spherical colloidal assemblies

Science.gov (United States)

Vogel, Nicolas; Utech, Stefanie; England, Grant T.; Shirman, Tanya; Phillips, Katherine R.; Koay, Natalie; Burgess, Ian B.; Kolle, Mathias; Weitz, David A.; Aizenberg, Joanna

2015-01-01

Materials in nature are characterized by structural order over multiple length scales have evolved for maximum performance and multifunctionality, and are often produced by self-assembly processes. A striking example of this design principle is structural coloration, where interference, diffraction, and absorption effects result in vivid colors. Mimicking this emergence of complex effects from simple building blocks is a key challenge for man-made materials. Here, we show that a simple confined self-assembly process leads to a complex hierarchical geometry that displays a variety of optical effects. Colloidal crystallization in an emulsion droplet creates micron-sized superstructures, termed photonic balls. The curvature imposed by the emulsion droplet leads to frustrated crystallization. We observe spherical colloidal crystals with ordered, crystalline layers and a disordered core. This geometry produces multiple optical effects. The ordered layers give rise to structural color from Bragg diffraction with limited angular dependence and unusual transmission due to the curved nature of the individual crystals. The disordered core contributes nonresonant scattering that induces a macroscopically whitish appearance, which we mitigate by incorporating absorbing gold nanoparticles that suppress scattering and macroscopically purify the color. With increasing size of the constituent colloidal particles, grating diffraction effects dominate, which result from order along the crystal’s curved surface and induce a vivid polychromatic appearance. The control of multiple optical effects induced by the hierarchical morphology in photonic balls paves the way to use them as building blocks for complex optical assemblies—potentially as more efficient mimics of structural color as it occurs in nature. PMID:26290583

Effect of Color Light Stimulation Using LED on Sleep Induction Time

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Seonjin Lee

2017-01-01

Full Text Available The effects of color are already being used widely. For this reason, in this study, an attempt was made to use such effects of color to examine the changes in sleep onset through the use of the preferred and nonpreferred color light stimulation. Color light stimulations were randomly presented to the subjects, and based on these colors, the changes in sleep onset were examined through the EEG. Also, to quantify the physiological changes that were caused by each color light stimulation, the changes in the HRV were examined through ECG to determine the level of activation of the autonomous nervous system. The results showed that sleep onset time was changed based on the light stimulation. The result of the EEG analysis showed that sleep onset time was most significantly shortened in preferred color light stimulation. Also, the result of HRV was the fastest change about both the time domain and the frequency domain in the preferred color light stimulation. Therefore, because the preferred color light stimulation activated the parasympathetic nervous system, sleep was induced quickly. Also, by simply using the HRV, the differences in the index of HRV showed changes of sleep onset according to the color light stimulation.

How does the color influence figure and shape formation, grouping, numerousness and reading? The role of chromatic wholeness and fragmentation.

Science.gov (United States)

Pinna, Baingio; Uccula, Arcangelo; Tanca, Maria

2010-09-01

In this work it is suggested that color induces phenomenal wholeness, part-whole organization and fragmentation. The phenomenal wholeness subsumes the set of its main attributes: homogeneity, continuity, univocality, belongingness, and oneness. If color induces wholeness, it can also induce fragmentation. Therefore, in order to understand the role played by color within the process of part-whole organization, color is used both as a wholeness and as a fragmentation tool, thus operating synergistically or antagonistically with other wholeness processes. Therefore, color is expected to influence figure-ground segregation, grouping, shape formation and other visual processes that are related to the phenomenal wholeness. The purpose of this study is to rate the influence of color in inducing whole and part-whole organization and, consequently, in determining the perception of figure-ground segregation, grouping, shape formation, numerousness evaluation and time reading. We manipulated experimental conditions by using equiluminant colors to favor or break (parcel-out) the wholeness of objects like geometrical composite figures and words. The results demonstrated that color is aimed, among other psychological and biological purposes, at: (1) relating each chromatic component of an object, thus favoring the emergence of the whole object; (2) eliciting a part-whole organization, whose components are interdependent; (3) eliciting fragments and then breaking up the whole and favoring the emergence of single components. Wholeness, part-whole organization and fragmentation can be considered as three further purposes of color. © 2010 The Authors, Ophthalmic and Physiological Optics © 2010 The College of Optometrists.

Tree Colors: Color Schemes for Tree-Structured Data.

Science.gov (United States)

Tennekes, Martijn; de Jonge, Edwin

2014-12-01

We present a method to map tree structures to colors from the Hue-Chroma-Luminance color model, which is known for its well balanced perceptual properties. The Tree Colors method can be tuned with several parameters, whose effect on the resulting color schemes is discussed in detail. We provide a free and open source implementation with sensible parameter defaults. Categorical data are very common in statistical graphics, and often these categories form a classification tree. We evaluate applying Tree Colors to tree structured data with a survey on a large group of users from a national statistical institute. Our user study suggests that Tree Colors are useful, not only for improving node-link diagrams, but also for unveiling tree structure in non-hierarchical visualizations.

Illuminant color estimation based on pigmentation separation from human skin color

Science.gov (United States)

Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

2015-03-01

Human has the visual system called "color constancy" that maintains the perceptive colors of same object across various light sources. The effective method of color constancy algorithm was proposed to use the human facial color in a digital color image, however, this method has wrong estimation results by the difference of individual facial colors. In this paper, we present the novel color constancy algorithm based on skin color analysis. The skin color analysis is the method to separate the skin color into the components of melanin, hemoglobin and shading. We use the stationary property of Japanese facial color, and this property is calculated from the components of melanin and hemoglobin. As a result, we achieve to propose the method to use subject's facial color in image and not depend on the individual difference among Japanese facial color.

Assessment of NPP VIIRS Ocean Color Data Products: Hope and Risk

Science.gov (United States)

Turpie, Kevin R.; Meister, Gerhard; Eplee, Gene; Barnes, Robert A.; Franz, Bryan; Patt, Frederick S.; Robinson, Wayne d.; McClain, Charles R.

2010-01-01

For several years, the NASA/Goddard Space Flight Center (GSFC) NPP VIIRS Ocean Science Team (VOST) provided substantial scientific input to the NPP project regarding the use of Visible Infrared Imaging Radiometer Suite (VIIRS) to create science quality ocean color data products. This work has culminated into an assessment of the NPP project and the VIIRS instrument's capability to produce science quality Ocean Color data products. The VOST concluded that many characteristics were similar to earlier instruments, including SeaWiFS or MODIS Aqua. Though instrument performance and calibration risks do exist, it was concluded that programmatic and algorithm issues dominate concerns. Keywords: NPP, VIIRS, Ocean Color, satellite remote sensing, climate data record.

INFRARED COLOR-COLOR DIAGRAMS FOR AGB STARS

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Kyung-Won Suh

2007-09-01

Full Text Available We present infrared color-color diagrams of AGB stars from the observations at near and mid infrared bands. We compile the observations for hundreds of OH/IR stars and carbon stars using the data from the Midcourse Space Experiment (MSX, the two micron sky survey (2MASS, and the IRAS point source catalog (PSC. We compare the observations with the theoretical evolutionary tracks of AGB stars. From the new observational data base and the theoretical evolution tracks, we discuss the meaning of the infrared color-color diagrams at different wavelengths.

Selective colors reflection from stratified aragonite calcium carbonate plates of mollusk shells.

Science.gov (United States)

Lertvachirapaiboon, Chutiparn; Parnklang, Tewarak; Pienpinijtham, Prompong; Wongravee, Kanet; Thammacharoen, Chuchaat; Ekgasit, Sanong

2015-08-01

An interaction between the incident light and the structural architecture within the shell of Asian green mussel (Perna viridis) induces observable pearlescent colors. In this paper, we investigate the influence of the structural architecture on the expressed colors. After a removal of the organic binder, small flakes from crushed shells show vivid rainbow reflection under an optical microscope. An individual flake expresses vivid color under a bright-field illumination while become transparent under a dark-field illumination. The expressed colors of the aragonite flakes are directly associated with its structural architecture. The flakes with aragonite thickness of 256, 310, and 353 nm, respectively, appear blue, green, and red under an optical microscope. The spectral simulation corroborates the experimentally observed optical effects as the flakes with thicker aragonite layers selectively reflected color with longer wavelengths. Flakes with multiple aragonite thicknesses expressed multi-color as the upper aragonite layers allow reflected colors from the lower layers to be observed. Copyright © 2015 Elsevier Inc. All rights reserved.

Color digital halftoning taking colorimetric color reproduction into account

Science.gov (United States)

Haneishi, Hideaki; Suzuki, Toshiaki; Shimoyama, Nobukatsu; Miyake, Yoichi

1996-01-01

Taking colorimetric color reproduction into account, the conventional error diffusion method is modified for color digital half-toning. Assuming that the input to a bilevel color printer is given in CIE-XYZ tristimulus values or CIE-LAB values instead of the more conventional RGB or YMC values, two modified versions based on vector operation in (1) the XYZ color space and (2) the LAB color space were tested. Experimental results show that the modified methods, especially the method using the LAB color space, resulted in better color reproduction performance than the conventional methods. Spatial artifacts that appear in the modified methods are presented and analyzed. It is also shown that the modified method (2) with a thresholding technique achieves a good spatial image quality.

Color preferences change after experience with liked/disliked colored objects.

Science.gov (United States)

Strauss, Eli D; Schloss, Karen B; Palmer, Stephen E

2013-10-01

How are color preferences formed, and can they be changed by affective experiences with correspondingly colored objects? We examined these questions by testing whether affectively polarized experiences with images of colored objects would cause changes in color preferences. Such changes are implied by the ecological valence theory (EVT), which posits that color preferences are determined by people's average affective responses to correspondingly colored objects (Palmer & Schloss, Proceedings of the National Academy of Sciences, 107, 8877-8882, 2010). Seeing images of strongly liked (and disliked) red and green objects, therefore, should lead to increased (and decreased) preferences for correspondingly colored red and green color patches. Experiment 1 showed that this crossover interaction did occur, but only if participants were required to evaluate their preferences for the colored objects when they saw them. Experiment 2 showed that these overall changes decreased substantially over a 24-h delay, but the degree to which the effect lasted for individuals covaried with the magnitude of the effects immediately after object exposure. Experiment 3 demonstrated a similar, but weaker, effect of affectively biased changes in color preferences when participants did not see, but only imagined, the colored objects. The overall pattern of results indicated that color preferences are not fixed, but rather are shaped by affective experiences with colored objects. Possible explanations for the observed changes in color preferences were considered in terms of associative learning through evaluative conditioning and/or priming of prior knowledge in memory.

Influence of color word availability on the Stroop color-naming effect.

Science.gov (United States)

Kim, Hyosun; Cho, Yang Seok; Yamaguchi, Motonori; Proctor, Robert W

2008-11-01

Three experiments tested whether the Stroop color-naming effect is a consequence of word recognition's being automatic or of the color word's capturing visual attention. In Experiment 1, a color bar was presented at fixation as the color carrier, with color and neutral words presented in locations above or below the color bar; Experiment 2 was similar, except that the color carrier could occur in one of the peripheral locations and the color word at fixation. The Stroop effect increased as display duration increased, and the Stroop dilution effect (a reduced Stroop effect when a neutral word is also present) was an approximately constant proportion of the Stroop effect at all display durations, regardless of whether the color bar or color word was at fixation. In Experiment 3, the interval between the onsets of the to-be-named color and the color word was manipulated. The Stroop effect decreased with increasing delay of the color word onset, but the absolute amount of Stroop dilution produced by the neutral word increased. This study's results imply that an attention shift from the color carrier to the color word is an important factor modulating the size of the Stroop effect.

Representing Color Ensembles.

Science.gov (United States)

Chetverikov, Andrey; Campana, Gianluca; Kristjánsson, Árni

2017-10-01

Colors are rarely uniform, yet little is known about how people represent color distributions. We introduce a new method for studying color ensembles based on intertrial learning in visual search. Participants looked for an oddly colored diamond among diamonds with colors taken from either uniform or Gaussian color distributions. On test trials, the targets had various distances in feature space from the mean of the preceding distractor color distribution. Targets on test trials therefore served as probes into probabilistic representations of distractor colors. Test-trial response times revealed a striking similarity between the physical distribution of colors and their internal representations. The results demonstrate that the visual system represents color ensembles in a more detailed way than previously thought, coding not only mean and variance but, most surprisingly, the actual shape (uniform or Gaussian) of the distribution of colors in the environment.

Luminance contours can gate afterimage colors and 'real' colors

NARCIS (Netherlands)

Anstis, S.; Vergeer, M.L.T.; Lier, R.J. van

2012-01-01

It has long been known that colored images may elicit afterimages in complementary colors. We have already shown (Van Lier, Vergeer, & Anstis, 2009) that one and the same adapting image may result in different afterimage colors, depending on the test contours presented after the colored image. The

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. <

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.

Characterization of Angle Dependent Color Travel of Printed Multi-Color Effect Pigment on Different Color Substrates

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Mirica Karlovits

2015-03-01

Full Text Available Color-travel pigments, which exhibit much more extensive color change as well provide angle-dependent optical effect can be used in many industrial products. In present paper the multi-color effect pigment printed on three different foils with different background color (black, silver and transparent was investigated. The pigment was based on synthetically produced transparent silicon dioxide platelets coated with titanium dioxide. CIEL*a*b* values and reflection of prints were measured by multi-angle spectrophotometer at constant illumination at an angle of 45º and different viewing angles (-15º, 15°, 25º, 45º, 75º and 110º were used. The measurements of printed multi-color pigment showed that CIEL*a*b* color coordinates varied to great extents, depending on detection angles as well on color of the printing substrate. The study revealed that pigmnet printed on black background obtained significant change in color. The study has also shown that when viewing angle increases, the reflection curves decreases.

P1-10: The Association between Colors and Emotions

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Yen-Yu Chen

2012-10-01

Full Text Available Wexner (1954 Journal of Applied Psychology 38 432–435 demonstrated colors were associated with specific emotions. Colors have many meanings, such as that red can lead to induce positive or negative emotions (Kaya & Epps, 2011 College Student Journal 38 396–406. This study extends previous findings and aims to investigate two questions, (1 whether colors are associated with the emotions of pictures in IAPS (International Affective Picture System and (2 whether perceiving IAPS consciously and unconsciously has different emotion associations. We replaced facial expressions with pictures of IAPS as stimuli. Five colors (black, red, yellow, blue, and white and 3 categories of IAPS (fear, awe, and amusement were manipulated in this study. Pictures were displayed in different durations to manipulate conscious (250 ms and unconscious (33 ms visual stimuli (Manuel & Pedro, 2009 Behavior Research Method 41 184–191 in two experiments. Participants were required to select the most suitable color at their first glance when the pictures of IAPS were presented, and vice versa. Results showed that overall association between colors and pictures of IAPS was weak but the association pattern was meaningful. It concluded (1 black and red colors are associated with the fearful emotion, and blue color is associated with the happy emotion; (2 white colors do not associate with the fear emotion, which is incongruent with the previous study (Osvaldo & Paul, 2007 Colour: Design & Creativity 1 1–20; (3 participants did not perform differently between conscious and unconscious stimulus conditions.

Color change at the push of a buttom; Farbwechsel auf Knopfdruck

Energy Technology Data Exchange (ETDEWEB)

Mortimer, Roger J. [Loughborough Univ. (United Kingdom)

2013-05-15

Materials with electrically switchable color open up many fascinating application possibilities - from the glare protection on low-cost displays to adaptive camouflage. Electrochromic materials can be electrically switched between different colors back and forth. The effect is based on a change of light absorption by current induced oxidation and reduction processes. Meanwhile electrochromic materials cover the entire color spectrum. In addition, the electrochromic materials are inexpensive and consume little power. This makes them attractive for many applications. However, their response times are still relatively long. The first commercial products include mirrors with automatic anti-glare and aircraft windows that can be darkened electrically.

Pseudo-Synesthesia through Reading Books with Colored Letters

Science.gov (United States)

Colizoli, Olympia; Murre, Jaap M. J.; Rouw, Romke

2012-01-01

Background Synesthesia is a phenomenon where a stimulus produces consistent extraordinary subjective experiences. A relatively common type of synesthesia involves perception of color when viewing letters (e.g. the letter ‘a’ always appears as light blue). In this study, we examine whether traits typically regarded as markers of synesthesia can be acquired by simply reading in color. Methodology/Principal Findings Non-synesthetes were given specially prepared colored books to read. A modified Stroop task was administered before and after reading. A perceptual crowding task was administered after reading. Reading one book (>49,000 words) was sufficient to induce effects regarded as behavioral markers for synesthesia. The results of the Stroop tasks indicate that it is possible to learn letter-color associations through reading in color (F(1, 14) = 5.85, p = .030). Furthermore, Stroop effects correlated with subjective reports about experiencing letters in color (r(13) = 0.51, p = .05). The frequency of viewing letters is related to the level of association as seen by the difference in the Stroop effect size between upper- and lower-case letters (t(14) = 2.79, p = .014) and in a subgroup of participants whose Stroop effects increased as they continued to read in color. Readers did not show significant performance advantages on the crowding task compared to controls. Acknowledging the many differences between trainees and synesthetes, results suggest that it may be possible to acquire a subset of synesthetic behavioral traits in adulthood through training. Conclusion/Significance To our knowledge, this is the first evidence of acquiring letter-color associations through reading in color. Reading in color appears to be a promising avenue in which we may explore the differences and similarities between synesthetes and non-synesthetes. Additionally, reading in color is a plausible method for a long-term ‘synesthetic’ training program. PMID

COLOR IMAGES

Directory of Open Access Journals (Sweden)

Dominique Lafon

2011-05-01

Full Text Available The goal of this article is to present specific capabilities and limitations of the use of color digital images in a characterization process. The whole process is investigated, from the acquisition of digital color images to the analysis of the information relevant to various applications in the field of material characterization. A digital color image can be considered as a matrix of pixels with values expressed in a vector-space (commonly 3 dimensional space whose specificity, compared to grey-scale images, is to ensure a coding and a representation of the output image (visualisation printing that fits the human visual reality. In a characterization process, it is interesting to regard color image attnbutes as a set of visual aspect measurements on a material surface. Color measurement systems (spectrocolorimeters, colorimeters and radiometers and cameras use the same type of light detectors: most of them use Charge Coupled Devices sensors. The difference between the two types of color data acquisition systems is that color measurement systems provide a global information of the observed surface (average aspect of the surface: the color texture is not taken into account. Thus, it seems interesting to use imaging systems as measuring instruments for the quantitative characterization of the color texture.

Examination of Color-Lighting Control System Using Colored Paper User Interface

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Aida Hiroto

2016-01-01

Full Text Available In recent year, Full-Color LED Lighting that can be changed to various color such as red, green, blue has been appeared with development of LED Lighting. By Color-Lighting control, users affected such as concentrating and relaxing. Therefore, Color-lighting control will spread to various place such as home, offices, stations. However color-lighting control affected some disturbance such as daylight, display when Full-Color LED controlled indoors. Also, information devices control get difficult with information technology develop. I propose Color-Lighting Control System using Colored Paper User Interface(CLC/CPUI. The purpose of CLC/CPUI is that anyone can intuitively control Full-Color LED Lighting. CLC/CPUI uses colored paper as user interface by sensing the paper. CLC/CPUI realizes lighting color that user demanded to do feedback control. I conduct accuracy verification experiment of CLC/CPUI.

Colored Chaos

Science.gov (United States)

2004-01-01

[figure removed for brevity, see original site] Released 7 May 2004 This daytime visible color image was collected on May 30, 2002 during the Southern Fall season in Atlantis Chaos. The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation. Image information: VIS instrument. Latitude -34.5, Longitude 183.6 East (176.4 West). 38 meter/pixel resolution. Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D

Color vision test

Science.gov (United States)

... present from birth) color vision problems: Achromatopsia -- complete color blindness , seeing only shades of gray Deuteranopia -- difficulty telling ... Vision test - color; Ishihara color vision test Images Color blindness tests References Bowling B. Hereditary fundus dystrophies. In: ...

S3-3: Misbinding of Color and Motion in Human V2 Revealed by Color-Contingent Motion Adaptation

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Fang Fang

2012-10-01

Full Text Available Wu, Kanai, & Shimojo (2004 Nature 429 262 described a compelling illusion demonstrating a steady-state misbinding of color and motion. Here, we took advantage of the illusion and performed psychophysical and fMRI adaptation experiments to explore the neural mechanism of color-motion misbinding. The stimulus subtended 20 deg by 14 deg of visual angle and contained two sheets of random dots, one sheet moving up and the other moving down. On the upward-moving sheet, dots in the right-end area (4 deg by 14 deg were red, and the rest of the dots were green. On the downward-moving sheet, dots in the right-end area were green, and the rest of the dots were red. When subjects fixated at the center of the stimulus, they bound the color and motion of the dots in the right-end area erroneously–the red dots appeared to move downwards and the green dots appeared to move upwards. In the psychophysical experiment, we measured the color-contingent motion aftereffect in the right-end area after adaptation to the illusory stimulus. A significant aftereffect was observed as if subjects had adapted to the perceived binding of color and motion, rather than the physical binding. For example, after adaptation, stationary red dots appeared to move upwards, and stationary green dots appeared to move downwards. In the fMRI experiment, we measured direction-selective motion adaptation effects in V1, V2, V3, V4, V3A/B, and V5. Relative to other cortical areas, V2 showed a much stronger adaptation effect to the perceived motion direction (rather than the physical direction for both the red and green dots. Significantly, the fMRI adaptation effect in V2 correlated with the color-contingent motion aftereffect across twelve subjects. This study provides the first human evidence that color and motion could be misbound at a very early stage of visual processing.

Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

International Nuclear Information System (INIS)

Vasileva, A.A.; Nazarov, I.A.; Olshin, P.K.; Povolotskiy, A.V.; Sokolov, I.A.; Manshina, A.A.

2015-01-01

Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium–phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass. - Graphical abstract: Formation of silver NPs on the surface of 0.5Ag 2 O–0.4P 2 O 5 –0,1Nb 2 O 5 glass induced by CW laser irradiation. - Highlights: • The structure of 0.5Ag 2 O–0.1Nb 2 O 5 –0.4P 2 O 5 and 0.55Ag 2 O–0.45P 2 O 5 glasses was investigated by Raman spectroscopy. • Fs laser writing induces formation of silver NPs in investigated glasses. • Surface plasmon resonance in the absorption spectra confirms the formation of NP. • The possibility of CW laser induced formation of silver NPs on the surface of sample with niobium is shown

Colors, colored overlays, and reading skills

OpenAIRE

Uccula, Arcangelo; Enna, Mauro; Mulatti, Claudio

2014-01-01

In this article, we are concerned with the role of colors in reading written texts. It has been argued that colored overlays applied above written texts positively influence both reading fluency and reading speed. These effects would be particularly evident for those individuals affected by the so called Meares-Irlen syndrome, i.e., who experience eyestrain and/or visual distortions – e.g., color, shape, or movement illusions – while reading. This condition would interest the 12–14% of the ge...

Space Environmental Effects on Colored Coatings and Anodizes

Science.gov (United States)

Kamenetzky, Rachel R.; Finckenor, Miria M.; Vaughn, Jason A.

1999-01-01

Colored coatings and anodizes are used on spacecraft as markers and astronaut visual aids. These materials must be stable in the space environment and withstand atomic oxygen, ultraviolet radiation, particulate radiation, thermal cycling, and high vacuum without significant change in optical and mechanical properties. A variety of colored coatings and anodizes have been exposed to simulated space environments at Marshall Space Flight Center and also actual space environment as part of the Passive Optical Sample Assembly (POSA) - I flight experiment. Colored coatings were developed by AZ Technology, Huntsville, AL, under a NASA contract for International Space Station (ISS). These include yellow, red, blue, and black paints suitable for Extra-Vehicular Activity (EVA) visual aids and ISS emblems. AaChron, Inc., Minneapolis, MN, developed stable colored anodizes, also in yellow, red, blue, and black, for astronaut visual aids. These coatings were exposed in the laboratory to approximately 550 equivalent sun-hours of solar ultraviolet radiation and approximately 1 x 10(exp 21) atoms/sq cm of atomic oxygen in vacuum. The AZ Technology yellow colored coating, designated TMS800IY, and all four AaChron colored anodizes were flown on POSA-I. POSA-I was a Risk Mitigation Experiment for ISS. It was attached to the exterior of the Mir space station docking module by EVA and was exposed for 18 months. The laboratory-simulated space environment, the natural space environment and the unique environment of an orbiting, active space station and their effects on these developmental materials are discussed.

Color Appearance of the Neon Color Spreading Effect

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Damir Vusić

2017-04-01

Full Text Available As a part of this paper, the influence of various parameters within the target process of graphic reproduction on the color appearance of the neon color spreading effect was investigated. The shift in a color appearance qualitatively is determined through the calculation of changes in perceptual attributes of color, i.e. differences in lightness, chroma and hue. The influence of different media (printed images, and LCD display in the “cross-media” system was examined, as well as the role of the inserted segment color choice and background of the primary stimulus as an element of design solutions. These parameters were evaluated in a variety of ambient conditions and under the observation of three CIE standard light sources and illuminants. It was found that it was mostly the changes of the chroma and lightness. The change in the color hue is the lowest.

Using Single Colors and Color Pairs to Communicate Basic Tastes

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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.

Marshak Lectureship: Vibrational properties of isolated color centers in diamond

Science.gov (United States)

Alkauskas, Audrius

In this talk we review our recent work on first-principles calculations of vibrational properties of isolated defect spin qubits and single photon emitters in diamond. These properties include local vibrational spectra, luminescence lineshapes, and electron-phonon coupling. They are key in understanding physical mechanisms behind spin-selective optical initialization and read-out, quantum efficiency of single-photon emitters, as well as in the experimental identification of as yet unknown centers. We first present the methodology to calculate and analyze vibrational properties of effectively isolated defect centers. We then apply the methodology to the nitrogen-vacancy and the silicon-vacancy centers in diamond. First-principles calculations yield important new insights about these important defects. Work performed in collaboration with M. W. Doherty, A. Gali, E. Londero, L. Razinkovas, and C. G. Van de Walle. Supported by the Research Council of Lithuania (Grant M-ERA.NET-1/2015).

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.

Color-Blindness Study: Color Discrimination on the TICCIT System.

Science.gov (United States)

Asay, Calvin S.; Schneider, Edward W.

The question studied whether the specific seven TICCIT system colors used within color coding schemes can be a source of confusion, or not seen at all, by the color-blind segment of target populations. Subjects were 11 color-blind and three normally sighted students at Brigham Young University. After a preliminary training exercise to acquaint the…

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.

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...

Color naming

OpenAIRE

Şahin, Ebru

1998-01-01

Ankara : Bilkent University, Department of Interior Architecture and Environmental Design and Institute of Fine Arts, 1998. Thesis (Ph.D) -- Bilkent University, 1998 Includes bibliographical refences. In this study, visual aspects of color and neurophysiological processes involved in the phenomenon, language of color and color models were explained in addition to the discussion of different ideas, orientations and previous works behind the subject of matter. Available color ...

Accurate color measurement methods for medical displays.

Science.gov (United States)

Saha, Anindita; Kelley, Edward F; Badano, Aldo

2010-01-01

The necessity for standard instrumentation and measurements of color that are repeatable and reproducible is the major motivation behind this work. Currently, different instrumentation and methods can yield very different results when measuring the same feature such as color uniformity or color difference. As color increasingly comes into play in medical imaging diagnostics, display color will have to be quantified in order to assess whether the display should be used for imaging purposes. The authors report on the characterization of three novel probes for measuring display color with minimal contamination from screen areas outside the measurement spot or from off-normal emissions. They compare three probe designs: A modified small-spot luminance probe and two conic probe designs based on black frusta. To compare the three color probe designs, spectral and luminance measurements were taken with specialized instrumentation to determine the luminance changes and color separation abilities of the probes. The probes were characterized with a scanning slit method, veiling glare, and a moving laser and LED arrangement. The scanning slit measurement was done using a black slit plate over a white line on an LCD monitor. The luminance was measured in 1 mm increments from the center of the slit to +/- 15 mm above and below the slit at different distances between the probe and the slit. The veiling glare setup consisted of measurements of the luminance of a black spot pattern with a white disk of radius of 100 mm as the black spot increases in 1 mm radius increments. The moving LED and laser method consisted of a red and green light orthogonal to the probe tip for the light to directly shine into the probe. The green light source was moved away from the red source in 1 cm increments to measure color stray-light contamination at different probe distances. The results of the color testing using the LED and laser methods suggest a better performance of one of the frusta probes

Color response and color transport in a quark-gluon plasma

International Nuclear Information System (INIS)

Heinz, U.

1986-01-01

Using color kinetic theory, we discuss color conduction and color response in a quark-gluon plasma. Collective color oscillations and their damping rates are investigated. An instability of the thermal equilibrium state in high T QCD is discovered

Cognitive aspects of color

Science.gov (United States)

Derefeldt, Gunilla A. M.; Menu, Jean-Pierre; Swartling, Tiina

1995-04-01

This report surveys cognitive aspects of color in terms of behavioral, neuropsychological, and neurophysiological data. Color is usually defined as psychophysical color or as perceived color. Behavioral data on categorical color perception, absolute judgement of colors, color coding, visual search, and visual awareness refer to the more cognitive aspects of color. These are of major importance in visual synthesis and spatial organization, as already shown by the Gestalt psychologists. Neuropsychological and neurophysiological findings provide evidence for an interrelation between cognitive color and spatial organization. Color also enhances planning strategies, as has been shown by studies on color and eye movements. Memory colors and the color- language connections in the brain also belong among the cognitive aspects of color.

Color response and color transport in a quark-gluon plasma

International Nuclear Information System (INIS)

Heinz, U.

1986-01-01

Using color kinetic theory, the authors discuss color conduction and color response in a quark-gluon plasma. Collective color oscillations and their damping rates are investigated. An instability of the thermal equilibrium state in high T QCD is discovered

A Study of Color Transformation on Website Images for the Color Blind

OpenAIRE

Siew-Li Ching; Maziani Sabudin

2010-01-01

In this paper, we study on color transformation method on website images for the color blind. The most common category of color blindness is red-green color blindness which is viewed as beige color. By transforming the colors of the images, the color blind can improve their color visibility. They can have a better view when browsing through the websites. To transform colors on the website images, we study on two algorithms which are the conversion techniques from RGB colo...

Color reproduction system based on color appearance model and gamut mapping

Science.gov (United States)

Cheng, Fang-Hsuan; Yang, Chih-Yuan

2000-06-01

By the progress of computer, computer peripherals such as color monitor and printer are often used to generate color image. However, cross media color reproduction by human perception is usually different. Basically, the influence factors are device calibration and characterization, viewing condition, device gamut and human psychology. In this thesis, a color reproduction system based on color appearance model and gamut mapping is proposed. It consists of four parts; device characterization, color management technique, color appearance model and gamut mapping.

Color inference in visual communication: the meaning of colors in recycling.

Science.gov (United States)

Schloss, Karen B; Lessard, Laurent; Walmsley, Charlotte S; Foley, Kathleen

2018-01-01

People interpret abstract meanings from colors, which makes color a useful perceptual feature for visual communication. This process is complicated, however, because there is seldom a one-to-one correspondence between colors and meanings. One color can be associated with many different concepts (one-to-many mapping) and many colors can be associated with the same concept (many-to-one mapping). We propose that to interpret color-coding systems, people perform assignment inference to determine how colors map onto concepts. We studied assignment inference in the domain of recycling. Participants saw images of colored but unlabeled bins and were asked to indicate which bins they would use to discard different kinds of recyclables and trash. In Experiment 1, we tested two hypotheses for how people perform assignment inference. The local assignment hypothesis predicts that people simply match objects with their most strongly associated color. The global assignment hypothesis predicts that people also account for the association strengths between all other objects and colors within the scope of the color-coding system. Participants discarded objects in bins that optimized the color-object associations of the entire set, which is consistent with the global assignment hypothesis. This sometimes resulted in discarding objects in bins whose colors were weakly associated with the object, even when there was a stronger associated option available. In Experiment 2, we tested different methods for encoding color-coding systems and found that people were better at assignment inference when color sets simultaneously maximized the association strength between assigned color-object parings while minimizing associations between unassigned pairings. Our study provides an approach for designing intuitive color-coding systems that facilitate communication through visual media such as graphs, maps, signs, and artifacts.

A subjective evaluation of high-chroma color with wide color-gamut display

Science.gov (United States)

Kishimoto, Junko; Yamaguchi, Masahiro; Ohyama, Nagaaki

2009-01-01

Displays tends to expand its color gamut, such as multi-primary color display, Adobe RGB and so on. Therefore displays got possible to display high chroma colors. However sometimes, we feel unnatural some for the image which only expanded chroma. Appropriate gamut mapping method to expand color gamut is not proposed very much. We are attempting preferred expanded color reproduction on wide color gamut display utilizing high chroma colors effectively. As a first step, we have conducted an experiment to investigate the psychological effect of color schemes including highly saturated colors. We used the six-primary-color projector that we have developed for the presentation of test colors. The six-primary-color projector's gamut volume in CIELAB space is about 1.8 times larger than the normal RGB projector. We conducted a subjective evaluation experiment using the SD (Semantic Differential) technique to find the quantitative psychological effect of high chroma colors.

Electronic transitions in quantum dots and rings induced by inhomogeneous off-centered light beams.

Science.gov (United States)

Quinteiro, G F; Lucero, A O; Tamborenea, P I

2010-12-22

We theoretically investigate the effect of inhomogeneous light beams with (twisted light) and without (plane-wave light) orbital angular momentum on semiconductor-based nanostructures, when the symmetry axes of the beam and the nanostructure are displaced parallel to each other. Exact analytical results are obtained by expanding the off-centered light field in terms of the appropriate light modes centered around the nanostructure. We demonstrate how electronic transitions involving the transfer of different amounts of orbital angular momentum are switched on and off as a function of the separation between the axes of the beam and the system. In particular, we show that even off-centered plane-wave beams induce transitions such that the angular momenta of the initial and final states are different.

Role of color memory in successive color constancy.

Science.gov (United States)

Ling, Yazhu; Hurlbert, Anya

2008-06-01

We investigate color constancy for real 2D paper samples using a successive matching paradigm in which the observer memorizes a reference surface color under neutral illumination and after a temporal interval selects a matching test surface under the same or different illumination. We find significant effects of the illumination, reference surface, and their interaction on the matching error. We characterize the matching error in the absence of illumination change as the "pure color memory shift" and introduce a new index for successive color constancy that compares this shift against the matching error under changing illumination. The index also incorporates the vector direction of the matching errors in chromaticity space, unlike the traditional constancy index. With this index, we find that color constancy is nearly perfect.

Effects of a static electric field on two-color photoassociation between different atoms

International Nuclear Information System (INIS)

Chakraborty, Debashree; Deb, Bimalendu

2014-01-01

We study non-perturbative effects of a static electric field on two-color photoassociation of different atoms. A static electric field induces anisotropy in scattering between two different atoms and hybridizes field-free rotational states of heteronuclear dimers or polar molecules. In a previous paper [D. Chakraborty et al., J. Phys. B 44, 095201 (2011)], the effects of a static electric field on one-color photoassociation between different atoms has been described through field-modified ground-state scattering states, neglecting electric field effects on heteronuclear diatomic bound states. To study the effects of a static electric field on heteronuclear bound states, and the resulting influence on Raman-type two-color photoassociation between different atoms in the presence of a static electric field, we develop a non-perturbative numerical method to calculate static electric field-dressed heteronuclear bound states. We show that the static electric field induced scattering anisotropy as well as hybridization of rotational states strongly influence two-color photoassociation spectra, leading to significant enhancement in PA rate and large shift. In particular, for static electric field strengths of a few hundred kV/cm, two-color PA rate involving high-lying bound states in electronic ground-state increases by several orders of magnitude even in the weak photoassociative coupling regime

UV-VUV laser induced phenomena in SiO2 glass

International Nuclear Information System (INIS)

Kajihara, Koichi; Ikuta, Yoshiaki; Oto, Masanori; Hirano, Masahiro; Skuja, Linards; Hosono, Hideo

2004-01-01

Creation and annihilation of point defects were studied for SiO 2 glass exposed to ultraviolet (UV) and vacuum UV (VUV) lights to improve transparency and radiation toughness of SiO 2 glass to UV-VUV laser light. Topologically disordered structure of SiO 2 glass featured by the distribution of Si-O-Si angle is a critical factor degrading transmittance near the fundamental absorption edge. Doping with terminal functional groups enhances the structural relaxation and reduces the number of strained Si-O-Si bonds by breaking up the glass network without creating the color centers. Transmittance and laser toughness of SiO 2 glass for F 2 laser is greatly improved in fluorine-doped SiO 2 glass, often referred as 'modified silica glass'. Interstitial hydrogenous species are mobile and reactive at ambient temperature, and play an important role in photochemical reactions induced by exposure to UV-VUV laser light. They terminate the dangling-bond type color centers, while enhancing the formation of the oxygen vacancies. These findings are utilized to develop a deep-UV optical fiber transmitting ArF laser photons with low radiation damage

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.

2013 Early Career Achievement Award--Proteomics of muscle- and species-specificity in meat color stability.

Science.gov (United States)

Suman, S P; Rentfrow, G; Nair, M N; Joseph, P

2014-03-01

Meat color is the most important quality trait influencing consumer purchase decisions. The interinfluential interactions between myoglobin and biomolecules govern color stability in meat. The advances in proteomics, such as high throughput analytical tools in mass spectrometry, 2-dimensional electrophoresis, and bioinformatics, offer themselves as robust techniques to characterize the proteome basis of muscle- and species-specific meat color phenomena. Differential abundance of chaperones and antioxidant proteins contributes to muscle-specific color stability in beef; the greater abundance of chaperones and antioxidant proteins in color-stable Longissimus lumborum than in color-labile Psoas major protects myoglobin and contributes to superior color stability of beef Longissimus steaks. Lipid oxidation-induced myoglobin oxidation is more critical to beef color than pork color due to the inherent differences in myoglobin chemistry; the number of nucleophilic histidine residues adducted by reactive aldehydes is greater in beef myoglobin than in pork myoglobin. Preferential adduction of secondary products of lipid oxidation to beef myoglobin accelerates metmyoglobin formation at a greater degree than in its pork counterpart. Mass spectrometric investigations revealed that although cherry-red carboxymyoglobin is more stable than oxymyoglobin, both redox forms undergo lipid oxidation-induced oxidation in model systems. The accuracy of mass spectrometry to detect the molecular mass of proteins has been applied to differentiate myoglobins from closely related meat animals, such as goats and sheep or emu and ostrich. In addition, this approach indicated that turkey myoglobin is 350 Da greater in molecular mass than beef myoglobin, and the unique biochemistry of turkey myoglobin could be responsible for its greater thermostability in model systems as well as the pink color defect observed in fully cooked uncured turkey products.

Color Space and Its Divisions: Color Order from Antiquity to the Present

Science.gov (United States)

Kuehni, Rolf G.

2003-03-01

It has been postulated that humans can differentiate between millions of gradations in color. Not surprisingly, no completely adequate, detailed catalog of colors has yet been devised, however the quest to understand, record, and depict color is as old as the quest to understand the fundamentals of the physical world and the nature of human consciousness. Rolf Kuehni's Color Space and Its Divisions: Color Order from Antiquity to the Present represents an ambitious and unprecedented history of man's inquiry into color order, focusing on the practical applications of the most contemporary developments in the field. Kuehni devotes much of his study to geometric, three-dimensional arrangements of color experiences, a type of system developed only in the mid-nineteenth century. Color spaces are of particular interest for color quality-control purposes in the manufacturing and graphics industries. The author analyzes three major color order systems in detail: Munsell, OSA-UCS, and NCS. He presents historical and current information on color space developments in color vision, psychology, psychophysics, and color technology. Chapter topics include: A historical account of color order systems Fundamentals of psychophysics and the relationship between stimuli and experience Results of perceptual scaling of colors according to attributes History of the development of mathematical color space and difference formulas Analysis of the agreements and discrepancies in psychophysical data describing color differences An experimental plan for the reliable, replicated perceptual data necessary to make progress in the field Experts in academia and industry, neuroscientists, designers, art historians, and anyone interested in the nature of color will find Color Space and Its Divisions to be the authoritative reference in its field.

Strategizing for the Future: Evolving Cultural Resource Centers in Higher Education

Science.gov (United States)

Shek, Yen Ling

2013-01-01

Cultural resource centers have been an ongoing and integral component to creating a more welcoming campus climate for Students of Color since its establishment in the 1960s. While the racial dynamics may have changed, many of the challenges Students of Color faced on predominantly White campuses have not. Interestingly, cultural resource centers…

COLORS AND COLOR GRADIENTS IN BULGES OF GALAXIES

NARCIS (Netherlands)

BALCELLS, M; PELETIER, RF

We have obtained surface photometry in U, B, R, and I for a complete optically selected sample of 45 early-type spiral galaxies, to investigate the colors and color gradients of spiral bulges. Color profiles in U-R, B-R, U-B, and R-I have been determined in wedges opening on the semiminor axes.

Examination of Color-Lighting Control System Using Colored Paper User Interface

OpenAIRE

Aida Hiroto; Matsui Kento; Keisuke Soma; Murakami Hiroki; Miki Mistunori

2016-01-01

In recent year, Full-Color LED Lighting that can be changed to various color such as red, green, blue has been appeared with development of LED Lighting. By Color-Lighting control, users affected such as concentrating and relaxing. Therefore, Color-lighting control will spread to various place such as home, offices, stations. However color-lighting control affected some disturbance such as daylight, display when Full-Color LED controlled indoors. Also, information devices control get difficul...

Phylloedes tumor of breast: findings at mammography, sonography and color Doppler imaging

International Nuclear Information System (INIS)

Park, Kun Choon; Ahn, Sei Hyun; Kim, Young Hwan; Choi, Hye Yong; Baek, Seung Yon; Yoon, Jeong Hyun

1994-01-01

The phylloides tumor of the breast is rare. the purposes of this study were to find the characteristic findings at mammography, sonography, and color Doppler imaging and to evaluate the usefulness of color Doppler study as an additional modality in the diagnosis of phylloides tumor and differentiation between benign and malignant varieties. Eight cases, who were pathologically proven as pylloides tumors, were retrospectively studied. The findings at histologic examination suggested benign in five, malignantin two, and borderline in one. We analyzed the mammograms of all eight patients and sonogram and color Doppler images of four patients. Phylloides tumors were seen as dense masses with lobulated margins in mammograms. On sonography, they showed relatively well-defined masses with in homogenous internal echo pattern and central echogenic areas. They were characterized by the presence of arterial and venous flows in the center and periphery of the lesion on color Doppler imaging and spectral analysis. We conclude that mammographic, sonographic and even color Doppler findings are not predictive of benign or malignant nature of the phylloides tumor. However, mammography and sonography with color Doppler interrogation are helpful in the diagnosis of phylloides tumor

Combining fine texture and coarse color features for color texture classification

Science.gov (United States)

Wang, Junmin; Fan, Yangyu; Li, Ning

2017-11-01

Color texture classification plays an important role in computer vision applications because texture and color are two fundamental visual features. To classify the color texture via extracting discriminative color texture features in real time, we present an approach of combining the fine texture and coarse color features for color texture classification. First, the input image is transformed from RGB to HSV color space to separate texture and color information. Second, the scale-selective completed local binary count (CLBC) algorithm is introduced to extract the fine texture feature from the V component in HSV color space. Third, both H and S components are quantized at an optimal coarse level. Furthermore, the joint histogram of H and S components is calculated, which is considered as the coarse color feature. Finally, the fine texture and coarse color features are combined as the final descriptor and the nearest subspace classifier is used for classification. Experimental results on CUReT, KTH-TIPS, and New-BarkTex databases demonstrate that the proposed method achieves state-of-the-art classification performance. Moreover, the proposed method is fast enough for real-time applications.

A relativistic colored spinning particle in an external color field

International Nuclear Information System (INIS)

Heinz, U.

1984-01-01

I derive fully covariant equations of motion for a classical colored spinning particle in an external SU(3) color field. Although the total color charge and total spin of the particle are found to be separately constants of motion (here I disagree with a recent paper by Arodz), the dynamics of the orientation of the color and spin vectors are coupled to each other through interaction with the color field, even if the latter is homogeneous. (orig.)

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 management of porcelain veneers: influence of dentin and resin cement colors.

Science.gov (United States)

Dozic, Alma; Tsagkari, Maria; Khashayar, Ghazal; Aboushelib, Moustafa

2010-01-01

Porcelain veneers have become an interesting treatment option to correct the shape and color of anterior teeth. Because of their limited thickness and high translucency, achieving a good color match is influenced by several variables. The aim of this work was to investigate the influence of natural dentin and resin cement colors on final color match of porcelain veneers. A preselected shade tab (A1) was chosen as the target color for a maxillary central incisor, and its color parameters (L*a*b*) were measured using a digital spectrophotometer (SpectroShade, MHT). Nine natural dentin colors (Natural Die Material, Ivoclar Vivadent) representing a wide range of tooth colors were used to prepare resin replicas of the maxillary central incisor with a standard preparation for porcelain veneers. The prepared porcelain veneers (IPS Empress Esthetic, A1, 0.6 mm thick, Ivoclar Vivadent) were cemented on the resin dies (nine groups of natural dentin colors) using seven shades of resin cement (Variolink Veneers, Ivoclar Vivadent). The L*a*b* values of the cemented veneers were measured, and DE values were calculated against the preselected target color (A1). DE greater than 3.3 was considered as a significant color mismatch detectable by the human eye. The seven shades of resin cement had no significant influence on the final color of the veneers, as the measured DE values were almost identical for every test group. On the other hand, the color of natural dentin was a significant factor that influenced final color match. None of the 63 tested combinations (nine natural dentin colors and seven resin cement colors) produced an acceptable color match. Thin porcelain veneers cannot mask underlying tooth color even when different shades of resin cement are used. Incorporation of opaque porcelain (high chroma) may improve final color match.

P1-15: Categorical Color Perception of LED Illuminant Color for Deuteranomals

Directory of Open Access Journals (Sweden)

Saeko Oishi

2012-10-01

Full Text Available Color information has great value in our everyday lives, but it is not mindful of people with color vision deficiency (CVD. We can choose several color names to categorize a lot of colors around us. Eleven color names (white, black, red, green, yellow, blue, brown, orange, pink, and gray are known as basic color categories, but people with CVD cannot necessarily describe colors as people who are color vision normal (CVN do. Previous studies showed that it was hard for people with CVD to discriminate illuminant color from object color, and their color perception changed largely depending on experimental conditions. In this study we investigated categorical color perception of illuminant color for deuteranomals, using a mixture of light which consists of a red, a green, and a blue LED as a test stimulus. We tested those stimuli with three luminance levels (180 cd/m2, 18 cd/m2, 1.8 cd/m2 and two visual angles (10 deg, 0.5 deg. Subjects were three deuteranomals and three people who are CVN. Our result showed that the categorical color of mild deuteranomals was similar to that of those who were CVN, but that of severe deuteranomals was not. Severe deuteranomals judged more low chromatic colors as achromatic colors than those who were CVN. The smaller visual angle or lower luminance level the test stimulus had, the more deuteranomals confused color. The results suggest that the effect of the Bezold-Brucke phenomenon is greater to deuteranomals than to those who are CVN. Furthermore, deuteranomals use not only chromatic information but also luminance information when they describe color.

Colored tracks of heavy ion particles recorded on photographic color film

International Nuclear Information System (INIS)

Kuge, K.; Yasuda, N.; Kumagai, H.; Aoki, N.; Hasegawa, A.

2002-01-01

A new method to obtain the three-dimensional information on nuclear tracks was developed using color photography. Commercial color films were irradiated with ion beam and color-developed. The ion tracks were represented with color images in which different depths were indicated by different colors, and the three-dimensional information was obtained from color changes. Details of this method are reported, and advantages and limitations are discussed in comparison with a conventional method using a nuclear emulsion

Uncertainties in Coastal Ocean Color Products: Impacts of Spatial Sampling

Science.gov (United States)

Pahlevan, Nima; Sarkar, Sudipta; Franz, Bryan A.

2016-01-01

With increasing demands for ocean color (OC) products with improved accuracy and well characterized, per-retrieval uncertainty budgets, it is vital to decompose overall estimated errors into their primary components. Amongst various contributing elements (e.g., instrument calibration, atmospheric correction, inversion algorithms) in the uncertainty of an OC observation, less attention has been paid to uncertainties associated with spatial sampling. In this paper, we simulate MODIS (aboard both Aqua and Terra) and VIIRS OC products using 30 m resolution OC products derived from the Operational Land Imager (OLI) aboard Landsat-8, to examine impacts of spatial sampling on both cross-sensor product intercomparisons and in-situ validations of R(sub rs) products in coastal waters. Various OLI OC products representing different productivity levels and in-water spatial features were scanned for one full orbital-repeat cycle of each ocean color satellite. While some view-angle dependent differences in simulated Aqua-MODIS and VIIRS were observed, the average uncertainties (absolute) in product intercomparisons (due to differences in spatial sampling) at regional scales are found to be 1.8%, 1.9%, 2.4%, 4.3%, 2.7%, 1.8%, and 4% for the R(sub rs)(443), R(sub rs)(482), R(sub rs)(561), R(sub rs)(655), Chla, K(sub d)(482), and b(sub bp)(655) products, respectively. It is also found that, depending on in-water spatial variability and the sensor's footprint size, the errors for an in-situ validation station in coastal areas can reach as high as +/- 18%. We conclude that a) expected biases induced by the spatial sampling in product intercomparisons are mitigated when products are averaged over at least 7 km × 7 km areas, b) VIIRS observations, with improved consistency in cross-track spatial sampling, yield more precise calibration/validation statistics than that of MODIS, and c) use of a single pixel centered on in-situ coastal stations provides an optimal sampling size for

Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition.

Science.gov (United States)

Yoo, Young Jin; Lee, Gil Ju; Jang, Kyung-In; Song, Young Min

2017-08-29

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.  We present an advanced method for fabricating ultra-thin color films with improved characteristics. The proposed process addresses several fabrication issues, including large area processing. Specifically, the protocol describes a process for fabricating ultra-thin color films using an electron beam evaporator for oblique angle deposition of germanium (Ge) and gold (Au) on silicon (Si) substrates.  Film porosity produced by the oblique angle deposition induces color changes in the ultra-thin film. The degree of color change depends on factors such as deposition angle and film thickness. Fabricated samples of the ultra-thin color films showed improved color tunability and color purity. In addition, the measured reflectance of the fabricated samples was converted into chromatic values and analyzed in terms of color. Our ultra-thin film fabricating method is expected to be used for various ultra-thin film applications such as flexible color electrodes, thin film solar cells, and optical filters. Also, the process developed here for analyzing the color of the fabricated samples is broadly useful for studying various color structures.

ColorTracker

NARCIS (Netherlands)

Holzheu, Stefanie; Lee, S.; Herneoja, Aulikki; Österlund, Toni; Markkanen, Piia

2016-01-01

With the work-in-progress research project ColorTracker we explore color as a formal design tool. This project-based paper describes a novel software application that processes color composition of a place and transcribes the data into three-dimensional geometries for architectural design. The

Colors in mind: a novel paradigm to investigate pure color imagery.

Science.gov (United States)

Wantz, Andrea L; Borst, Grégoire; Mast, Fred W; Lobmaier, Janek S

2015-07-01

Mental color imagery abilities are commonly measured using paradigms that involve naming, judging, or comparing the colors of visual mental images of well-known objects (e.g., "Is a sunflower darker yellow than a lemon"?). Although this approach is widely used in patient studies, differences in the ability to perform such color comparisons might simply reflect participants' general knowledge of object colors rather than their ability to generate accurate visual mental images of the colors of the objects. The aim of the present study was to design a new color imagery paradigm. Participants were asked to visualize a color for 3 s and then to determine a visually presented color by pressing 1 of 6 keys. We reasoned that participants would react faster when the imagined and perceived colors were congruent than when they were incongruent. In Experiment 1, participants were slower in incongruent than congruent trials but only when they were instructed to visualize the colors. The results in Experiment 2 demonstrate that the congruency effect reported in Experiment 1 cannot be attributed to verbalization of the color that had to be visualized. Finally, in Experiment 3, the congruency effect evoked by mental imagery correlated with performance in a perceptual version of the task. We discuss these findings with respect to the mechanisms that underlie mental imagery and patients suffering from color imagery deficits. (c) 2015 APA, all rights reserved.

Photoionization and trans-to-cis isomerization of β-cyclodextrin-encapsulated azobenzene induced by two-color two-laser-pulse excitation.

Science.gov (United States)

Takeshita, Tatsuya; Hara, Michihiro

2018-03-15

Azobenzene (1) and the complex resulting from the incorporation of 1 with cyclodextrin (1/CD) are attractive for light-driven applications such as micromachining and chemical biology tools. The highly sensitive photoresponse of 1 is crucial for light-driven applications containing both 1 and 1/CD to reach their full potential. In this study, we investigated the photoionization and trans-to-cis isomerization of 1/CD induced by one- and two-color two-laser pulse excitation. Photoionization of 1/CD, which was induced by stepwise two-photon absorption, was observed using laser pulse excitation at 266nm. Additionally, simultaneous irradiation with 266 and 532nm laser pulses increased the trans-to-cis isomerization yield (Υ t→c ) by 27%. It was concluded that the increase in Υ t→c was caused by the occurrence of trans-to-cis isomerization in the higher-energy singlet state (S n ), which was reached by S 1 →S n transition induced by laser pulse excitation at 532nm. The results of this study are potentially applicable in light-driven applications such as micromachining and chemical biology tools. Copyright © 2018 Elsevier B.V. All rights reserved.

Visual half-field presentations of incongruent color words: effects of gender and handedness.

Science.gov (United States)

Franzon, M; Hugdahl, K

1986-09-01

Right-handed (dextral) and left-handed (sinistral) males and females (N = 15) were compared for language lateralization in a visual half-field (VHF) incongruent color-words paradigm. The paradigm consists of repeated brief (less than 200 msec) presentations of color-words written in an incongruent color. Presentations are either to the right or to the left of center fixation. The task of the subject is to report the color the word is written in on each trial, ignoring the color-word. Color-bars and congruent color-words were used as control stimuli. Vocal reaction time (VRT) and error frequency were used as dependent measures. The logic behind the paradigm is that incongruent color-words should lead to a greater cognitive conflict when presented in the half-field contralateral to the dominant hemisphere. The results showed significantly longer VRTs in the right half-field for the dextral subjects. Furthermore, significantly more errors were observed in the male dextral group when the incongruent stimuli were presented in the right half-field. There was a similar trend in the data for the sinistral males. No differences between half-fields were observed for the female groups. It is concluded that the present results strengthen previous findings from our laboratory (Hugdahl and Franzon, 1985) that the incongruent color-words paradigm is a useful non-invasive technique for the study of lateralization in the intact brain.

Coloring mixed hypergraphs

CERN Document Server

Voloshin, Vitaly I

2002-01-01

The theory of graph coloring has existed for more than 150 years. Historically, graph coloring involved finding the minimum number of colors to be assigned to the vertices so that adjacent vertices would have different colors. From this modest beginning, the theory has become central in discrete mathematics with many contemporary generalizations and applications. Generalization of graph coloring-type problems to mixed hypergraphs brings many new dimensions to the theory of colorings. A main feature of this book is that in the case of hypergraphs, there exist problems on both the minimum and th

Photo-induced changes of silicate glasses optical parameters at multi-photon laser radiation absorption

International Nuclear Information System (INIS)

Efimov, O.M.; Glebov, L.B.; Mekryukov, A.M.

1995-01-01

In this paper the results of investigations of the mechanisms of photo-induced changes of alkali-silicate (crown) and lead-silicate (flint) glasses optical parameters upon the exposure to the intense laser radiation, and the basic regularities of these processes are reported. These investigations were performed in Research Center open-quotes S. I. Vavilov State Optical Instituteclose quotes during last 15 years. The kinetics of stable and unstable CC formation and decay, the effect of widely spread impurity ions on these processes, the characteristics of fundamental and impure luminescence, the kinetics of refractive index change under conditions of multi-photon glass matrix excitation, and other properties are considered. On the basis of analysis of received regularities it was shown that the nonlinear coloration of alkali-silicate glasses (the fundamental absorption edge is nearly 6 eV) takes place only as a result of two-photon absorption. Important efforts were aimed at the detection of three- or more photon matrix ionization of these glasses, but they were failed. However it was established that in the lead silicate glasses the long-wave carriers mobility boundary (> 5.6 eV) is placed considerably higher the fundamental absorption edge (∼ 3.5 eV) of material matrix. This results in that the linear color centers formation in the lead silicate glasses is not observed. The coloration of these glasses arises only from the two- or three-photon matrix ionization, and the excitation occurs through virtual states that are placed in the fundamental absorption region. In the report the available mechanisms of photo-induced changes of glasses optical parameters, and some applied aspects of this problem are discussed

Study of optical absorption in the ultraviolet region of mixed crystals ADA/ADP aiming to investigate defects and centers formed by ionizing radiation

International Nuclear Information System (INIS)

Schneider, S.

1978-01-01

The development of a crystal model to explain the ionizing radiation effect on the color centers is presented. The methods of crystal growth used in the sample preparation and the requirements necessary for an efficient optical study, such as area, thickness purity, etc, are described. The processes of color center production are analysed and the techniques used in the study of color centers, such as optical absorption, spectrometry and spin resonance, are described. The computer programs used in curve adjustment and the approximated calculation of centers per cm 3 are also presented. (M.C.K.) [pt

Is 24-color FISH detection of in-vitro radiation-induced chromosomal aberrations suited to determine individual intrinsic radiosensitivity?

International Nuclear Information System (INIS)

Kuechler, A.; Wendt, T.G.; Neubauer, S.; Grabenbauer, G.G.; Sauer, R.; Claussen, U.; Liehr, T.

2002-01-01

Background: Reliable determination of intrinsic radiosensitivity in individual patients is a serious need in radiation oncology. Chromosomal aberrations are sensitive indicators of a previous exposure to ionizing irradiation. Former molecular cytogenetic studies showed that such aberrations as an equivalent of intrinsic radiosensitivity can be detected by fluorescence in-situ hybridization (FISH) techniques using whole chromosome painting (wcp) probes. However, only one up to three randomly chosen wcp probes have been applied for such approaches until now. As a random distribution of chromosomal rearrangements along the chromosomes is up to now still controversial, the power of the 24-color FISH approach should be elucidated in the present study. Methods and Material: Lymphocytes derived from lymphoblastoid cell lines of one patient with Nijmegen breakage syndrome (NBS homozygote) and of two NBS heterozygotes and peripheral blood lymphocytes of two controls were analyzed. Samples of each patient/control were irradiated in vitro with 0.0 Gy, 0.7 Gy or 2.0 Gy prior to cultivation. Chromosomal aberrations were analyzed in detail and quantified by means of 24-color FISH as an expression of the individual intrinsic radiosensitivity. Results: 24-color FISH analyses were done in a total of 1,674 metaphases. After in-vitro irradiation, 21% (0.7 Gy) or 57% (2.0 Gy) of the controls' cells, 15% (0.7 Gy) or 53% (2.0 Gy) of the heterozygotes' cells and 54% (0.7 Gy) or 79% (2.0 Gy) of the homozygote's cells contained aberrations. The highest average rates of breaks per mitosis [B/M] (0.7 Gy: 1.80 B/M, 2.0 Gy: 4.03 B/M) and complex chromosomal rearrangements [CCR] (0.7 Gy: 0.20 CCR/M, 2.0 Gy: 0.47 CCR/M) were observed in the NBS patient. Moreover, the proportion of different aberration types after irradiation showed a distinct increase in the rate of CCR combined with a decrease in dicentrics in the NBS homozygote. Conclusion: To come to a more complete picture of radiation-induced

Coloring Rate of Phenolphthalein by Reaction with Alkaline Solution Observed by Liquid-Droplet Collision.

Science.gov (United States)

Takano, Yuuka; Kikkawa, Shigenori; Suzuki, Tomoko; Kohno, Jun-ya

2015-06-11

Many important chemical reactions are induced by mixing two solutions. This paper presents a new way to measure rates of rapid chemical reactions induced by mixing two reactant solutions using a liquid-droplet collision. The coloring reaction of phenolphthalein (H2PP) by a reaction with NaOH is investigated kinetically. Liquid droplets of H2PP/ethanol and NaOH/H2O solutions are made to collide, which induces a reaction that transforms H2PP into a deprotonated form (PP(2-)). The concentration of PP(2-) is evaluated from the RGB values of pixels in the colored droplet images, and is measured as a function of the elapsed time from the collision. The obtained rate constant is (2.2 ± 0.7) × 10(3) M(-1) s(-1), which is the rate constant for the rate-determining step of the coloring reaction of H2PP. This method was shown to be applicable to determine rate constants of rapid chemical reactions between two solutions.

Color and shade parameters of ultramarine zeolitic pigments synthesized from kaolin waste

International Nuclear Information System (INIS)

Menezes, Raquel Aranha de; Paz, Simone Patricia Aranha da; Angelica, Romulo Simoes; Neves, Roberto de Freitas; Pergher, Sibele Berenice Castella

2014-01-01

Ultramarine pigments were successful synthesized from zeolite A obtained from kaolin waste. This waste has been used as an excellent source of silicon and aluminum for zeolite synthesis because of its high kaolinite concentrations and low contents of other accessory minerals. The cost is naturally less than the industrialized product. Color additives (Sulfur and Sodium Carbonate) were mixed with different proportions of zeolite A and further calcined for 5 h at 500 °C. They were characterized by XRD and XRF in addition to visual classification by color and shade. These products show colors from blue to green at different shades, both influenced by the amount of additives and cooling rate after calcination. Thus, a different quantity of the same additives in the same zeolitic matrix provides an increase in the color intensity. Cooling rate after calcination induces the color change which is substantially important in the pigments production. (author)

Color and shade parameters of ultramarine zeolitic pigments synthesized from kaolin waste

Energy Technology Data Exchange (ETDEWEB)

Menezes, Raquel Aranha de; Paz, Simone Patricia Aranha da; Angelica, Romulo Simoes; Neves, Roberto de Freitas; Pergher, Sibele Berenice Castella, E-mail: raquel_arn@hotmail.com [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Inst. de Geociencias. Grupo de Mineralogia e Geoquimica Aplicada

2014-08-15

Ultramarine pigments were successful synthesized from zeolite A obtained from kaolin waste. This waste has been used as an excellent source of silicon and aluminum for zeolite synthesis because of its high kaolinite concentrations and low contents of other accessory minerals. The cost is naturally less than the industrialized product. Color additives (Sulfur and Sodium Carbonate) were mixed with different proportions of zeolite A and further calcined for 5 h at 500 °C. They were characterized by XRD and XRF in addition to visual classification by color and shade. These products show colors from blue to green at different shades, both influenced by the amount of additives and cooling rate after calcination. Thus, a different quantity of the same additives in the same zeolitic matrix provides an increase in the color intensity. Cooling rate after calcination induces the color change which is substantially important in the pigments production. (author)

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

Color Degree Sum Conditions for Rainbow Triangles in Edge-Colored Graphs

NARCIS (Netherlands)

Li, Ruonan; Ning, Bo; Zhang, Shenggui

Let G be an edge-colored graph and v a vertex of G. The color degree of v is the number of colors appearing on the edges incident to v. A rainbow triangle in G is one in which all edges have distinct colors. In this paper, we first prove that an edge-colored graph on n vertices contains a rainbow

Correlations between Abelian monopoles and center vortices

Energy Technology Data Exchange (ETDEWEB)

Hosseini Nejad, Seyed Mohsen, E-mail: smhosseininejad@ut.ac.ir; Deldar, Sedigheh, E-mail: sdeldar@ut.ac.ir

2017-04-15

We study the correlations between center vortices and Abelian monopoles for SU(3) gauge group. Combining fractional fluxes of monopoles, center vortex fluxes are constructed in the thick center vortex model. Calculating the potentials induced by fractional fluxes constructing the center vortex flux in a thick center vortex-like model and comparing with the potential induced by center vortices, we observe an attraction between fractional fluxes of monopoles constructing the center vortex flux. We conclude that the center vortex flux is stable, as expected. In addition, we show that adding a contribution of the monopole-antimonopole pairs in the potentials induced by center vortices ruins the Casimir scaling at intermediate regime.

What is Color Blindness?

Science.gov (United States)

... Color Blindness? Who Is at Risk for Color Blindness? Color Blindness Causes Color Blindness Diagnosis and Treatment How Color Blindness Is Tested What Is Color Blindness? Leer en Español: ¿Qué es el daltonismo? Written ...

Color Calibration for Colorized Vision System with Digital Sensor and LED Array Illuminator

Directory of Open Access Journals (Sweden)

Zhenmin Zhu

2016-01-01

Full Text Available Color measurement by the colorized vision system is a superior method to achieve the evaluation of color objectively and continuously. However, the accuracy of color measurement is influenced by the spectral responses of digital sensor and the spectral mismatch of illumination. In this paper, two-color vision system illuminated by digital sensor and LED array, respectively, is presented. The Polynomial-Based Regression method is applied to solve the problem of color calibration in the sRGB and CIE  L⁎a⁎b⁎ color spaces. By mapping the tristimulus values from RGB to sRGB color space, color difference between the estimated values and the reference values is less than 3ΔE. Additionally, the mapping matrix ΦRGB→sRGB has proved a better performance in reducing the color difference, and it is introduced subsequently into the colorized vision system proposed for a better color measurement. Necessarily, the printed matter of clothes and the colored ceramic tile are chosen as the application experiment samples of our colorized vision system. As shown in the experimental data, the average color difference of images is less than 6ΔE. It indicates that a better performance of color measurement is obtained via the colorized vision system proposed.

Animal Detection in Natural Images: Effects of Color and Image Database

Science.gov (United States)

Zhu, Weina; Drewes, Jan; Gegenfurtner, Karl R.

2013-01-01

The visual system has a remarkable ability to extract categorical information from complex natural scenes. In order to elucidate the role of low-level image features for the recognition of objects in natural scenes, we recorded saccadic eye movements and event-related potentials (ERPs) in two experiments, in which human subjects had to detect animals in previously unseen natural images. We used a new natural image database (ANID) that is free of some of the potential artifacts that have plagued the widely used COREL images. Color and grayscale images picked from the ANID and COREL databases were used. In all experiments, color images induced a greater N1 EEG component at earlier time points than grayscale images. We suggest that this influence of color in animal detection may be masked by later processes when measuring reation times. The ERP results of go/nogo and forced choice tasks were similar to those reported earlier. The non-animal stimuli induced bigger N1 than animal stimuli both in the COREL and ANID databases. This result indicates ultra-fast processing of animal images is possible irrespective of the particular database. With the ANID images, the difference between color and grayscale images is more pronounced than with the COREL images. The earlier use of the COREL images might have led to an underestimation of the contribution of color. Therefore, we conclude that the ANID image database is better suited for the investigation of the processing of natural scenes than other databases commonly used. PMID:24130744

Animal detection in natural images: effects of color and image database.

Directory of Open Access Journals (Sweden)

Weina Zhu

Full Text Available The visual system has a remarkable ability to extract categorical information from complex natural scenes. In order to elucidate the role of low-level image features for the recognition of objects in natural scenes, we recorded saccadic eye movements and event-related potentials (ERPs in two experiments, in which human subjects had to detect animals in previously unseen natural images. We used a new natural image database (ANID that is free of some of the potential artifacts that have plagued the widely used COREL images. Color and grayscale images picked from the ANID and COREL databases were used. In all experiments, color images induced a greater N1 EEG component at earlier time points than grayscale images. We suggest that this influence of color in animal detection may be masked by later processes when measuring reation times. The ERP results of go/nogo and forced choice tasks were similar to those reported earlier. The non-animal stimuli induced bigger N1 than animal stimuli both in the COREL and ANID databases. This result indicates ultra-fast processing of animal images is possible irrespective of the particular database. With the ANID images, the difference between color and grayscale images is more pronounced than with the COREL images. The earlier use of the COREL images might have led to an underestimation of the contribution of color. Therefore, we conclude that the ANID image database is better suited for the investigation of the processing of natural scenes than other databases commonly used.

Improved atom number with a dual color magneto—optical trap

International Nuclear Information System (INIS)

Cao Qiang; Luo Xin-Yu; Gao Kui-Yi; Wang Xiao-Rui; Wang Ru-Quan; Chen Dong-Min

2012-01-01

We demonstrate a novel dual color magneto—optical trap (MOT), which uses two sets of overlapping laser beams to cool and trap 87 Rb atoms. The volume of cold cloud in the dual color MOT is strongly dependent on the frequency difference of the laser beams and can be significantly larger than that in the normal MOT with single frequency MOT beams. Our experiment shows that the dual color MOT has the same loading rate as the normal MOT, but much longer loading time, leading to threefold increase in the number of trapped atoms. This indicates that the larger number is caused by reduced light induced loss. The dual color MOT is very useful in experiments where both high vacuum level and large atom number are required, such as single chamber quantum memory and Bose—Einstein condensation (BEC) experiments. Compared to the popular dark spontaneous-force optical trap (dark SPOT) technique, our approach is technically simpler and more suitable to low power laser systems. (rapid communication)

Clinical validation of a medical grade color monitor for chest radiology

Science.gov (United States)

Jacobs, J.; Zanca, F.; Verschakelen, J.; Marchal, G.; Bosmans, H.

2009-02-01

Until recently, the specifications of medical grade monochrome LCD monitors outperformed those of color LCD monitors. New generations of color LCD monitors, however, show specifications that are in many respects similar to those of monochrome monitors typically used in diagnostic workstations. The aim of present study was to evaluate the impact of different medical grade monitors in terms of detection of simulated lung nodules in chest x-ray images. Specifically, we wanted to compare a new medical grade color monitor (Barco Coronis 6MP color) to a medical grade grayscale monitor (Barco Coronis 3MP monochrome) and a consumer color monitor (Philips 200VW 1.7MP color) by means of an observer performance experiment. Using the free-response acquisition data paradigm, seven radiologists were asked to detect and locate lung nodules (170 in total), simulated in half of the 200 chest X-ray images used in the experiment. The jackknife free-response receiver operating characteristic (JAFROC) analysis of the data showed a statistically significant difference between at least two monitors, F-value=3.77 and p-value =0.0481. The different Figure of Merit values were 0.727, 0.723 and 0.697 for the new color LCD monitor, the medical grade monitor and the consumer color monitor respectively. There was no difference between the needed reading times but there was a difference between the mean calculated Euclidian distances between the position marked by the observers and the center of the simulated nodule, indicating a better accuracy with both medical grade monitors. Present data suggests that the new generation of medical grade color monitors could be used as diagnostic workstations.

Color change of tourmaline by heat treatment and electron beam irradiation: UV-Visible, EPR, and Mid-IR spectroscopic analyses

Science.gov (United States)

Maneewong, Apichate; Seong, Baek Seok; Shin, Eun Joo; Kim, Jeong Seog; Kajornrith, Varavuth

2016-01-01

The color of pink tourmaline gemstone changed to colorless when heating at temperature of 600 °C in air. This colorless tourmaline recovered its pink color when irradiated with an electron beam (e-beam) of 800 kGy. The origin of the color change was investigated in three types of tourmaline gemstones, two pink are from Afghanistan and one green are from Nigeria, by using Ultraviolet-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), Electron paramagnetic resonance (EPR), and Energy Dispersive X-ray Fluorescence (EDXRF). The UV-Vis absorption spectrum of the pink tourmaline with higher Mn concentration (T2, 0.24 wt%) showed characteristic absorption peaks originating from the Mn3+ color center: two absorption bands centered at wavelength of 396 and 520 nm, respectively. Both absorption bands disappeared when heated in air at 600 °C and then reappeared when irradiated with an e-beam at 800 kGy. EPR T2 spectra showed that the color change was related to the valence change of Mn3+ to Mn2+ and vice versa. The pink tourmaline of lower MnO content (T1, 0.08 wt%) also became colorless when heated, but the color was not recovered when the gemstone underwent e-beam irradiation. Instead, a yellow color was obtained. UV-Vis and FTIR spectra indicated that this yellow color originated from a decomposition of the hydroxyl group (-OH) into O- and Ho by the e-beam irradiation. Green tourmaline did not show any color change with either heat treatment or e-beam irradiation.

Color changes of vienna sausage by gamma irradiation

International Nuclear Information System (INIS)

Kume, Tamikazu; Aoki, Shohei; Sato, Tomotaro

1978-01-01

Color change of vienna sausage induced by gamma irradiation was investigated. Discoloration of irradiated vienna sausage was evaluated by use of the color difference meter and sensory test. The discoloration by irradiation was influenced by oxygen contents in packing pouches. In the case of commercial vienna sausage, significant difference from unirradiated control by 99% of probability was recognized at the doses of 1.0 Mrad in nitrogen, 0.5 Mrad in air and 0.3 Mrad in oxygen, respectively. The color change of the specially prepared vienna sausage (40% pork, 40% mutton, 20% beef, and no additional preservatives) was less than that of the commercial one. The absorbance at 540 nm of extracts from vienna sausages with 80% acetone decreased with increasing irradiation dose and oxygen content. While, change in absorbance at 340 nm was practically unaffected by the oxygen concentration. These results suggest that the degradation of nitroso-heme complex by irradiation causes mainly the discoloration of vienna sausage. (auth.)

Color of illumination during growth affects LHCII chiral macroaggregates in pea plant leaves.

Science.gov (United States)

Gussakovsky, Eugene E; Shahak, Yosepha; Schroeder, Dana F

2007-02-01

To determine whether the color of illumination under which plants are grown, affects the structure of photosynthetic antennae, pea plants were grown under either blue-enriched, red-enriched, or white light. Carotenoid content of isolated chloroplasts was found to be insensitive to the color of illumination during growth, while chlorophyll a/b ratio in chloroplasts isolated from young illuminated leaves showed susceptibility to color. Color of illumination affects the LHCII chiral macroaggregates in intact leaves and isolated chloroplasts, providing light-induced alteration of the handedness of the LHCII chiral macroaggregate, as measured with circular dichroism and circularly polarized luminescence. The susceptibility of handedness to current illumination (red light excitation of chlorophyll fluorescence) is dependent on the color under which the plants were grown, and was maximal for the red-enriched illumination. We propose the existence of a long-term (growth period) color memory, which influences the susceptibility of the handedness of LHCII chiral macroaggregates to current light.

Focal colors across languages are representative members of color categories.

Science.gov (United States)

Abbott, Joshua T; Griffiths, Thomas L; Regier, Terry

2016-10-04

Focal colors, or best examples of color terms, have traditionally been viewed as either the underlying source of cross-language color-naming universals or derived from category boundaries that vary widely across languages. Existing data partially support and partially challenge each of these views. Here, we advance a position that synthesizes aspects of these two traditionally opposed positions and accounts for existing data. We do so by linking this debate to more general principles. We show that best examples of named color categories across 112 languages are well-predicted from category extensions by a statistical model of how representative a sample is of a distribution, independently shown to account for patterns of human inference. This model accounts for both universal tendencies and variation in focal colors across languages. We conclude that categorization in the contested semantic domain of color may be governed by principles that apply more broadly in cognition and that these principles clarify the interplay of universal and language-specific forces in color naming.

Structural features of silver-doped phosphate glasses in zone of femtosecond laser-induced modification

Energy Technology Data Exchange (ETDEWEB)

Vasileva, A.A., E-mail: anvsilv@gmail.com [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation); Nazarov, I.A. [Saint-Petersburg State University, Department of Physics, Saint-Petersburg (Russian Federation); Olshin, P.K.; Povolotskiy, A.V. [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation); Sokolov, I.A. [St.Petersburg State Polytechnical University, St.Petersburg (Russian Federation); LTD “AtomTjazhMash”, St.Petersburg (Russian Federation); Manshina, A.A. [Saint-Petersburg State University, Institute of Chemistry, Saint-Petersburg (Russian Federation)

2015-10-15

Femtosecond (fs) laser writing of two-dimensional microstructures (waveguides) is demonstrated in bulk phosphate glasses doped with silver ions. Silver-content phosphate and silver-content niobium–phosphate glasses with high concentration of silver oxide 55 mol% were used as samples for fs laser writing. The chemical network structure of the synthesized samples is analyzed through Raman spectroscopy and was found to be strongly sensitive to Nb incorporation. It was found that the direct laser writing process enables not only reorganization of glass network, but also formation of color centers and silver nanoparticles that are revealed in appearance of luminescence signal and plasmon absorption. The process of NPs' formation is more efficient for Nb-phosphate glass, while color centers are preferably formed in phosphate glass. - Graphical abstract: Formation of silver NPs on the surface of 0.5Ag{sub 2}O–0.4P{sub 2}O{sub 5}–0,1Nb{sub 2}O{sub 5} glass induced by CW laser irradiation. - Highlights: • The structure of 0.5Ag{sub 2}O–0.1Nb{sub 2}O{sub 5}–0.4P{sub 2}O{sub 5} and 0.55Ag{sub 2}O–0.45P{sub 2}O{sub 5} glasses was investigated by Raman spectroscopy. • Fs laser writing induces formation of silver NPs in investigated glasses. • Surface plasmon resonance in the absorption spectra confirms the formation of NP. • The possibility of CW laser induced formation of silver NPs on the surface of sample with niobium is shown.

At-line cotton color measurements by portable color spectrophotometers

Science.gov (United States)

As a result of reports of cotton bales that had significant color changes from their initial Uster® High Volume Instrument (HVI™) color measurements, a program was implemented to measure cotton fiber color (Rd, +b) at-line in remote locations (warehouse, mill, etc.). The measurement of cotton fiber...

Effects of saturation and contrast polarity on the figure-ground organization of color on gray

OpenAIRE

Dresp-Langley, Birgitta; Reeves, Adam

2014-01-01

International audience; Poorly saturated colors are closer to a pure grey than strongly saturated ones and, therefore, appear less " colorful ". Color saturation is effectively manipulated in the visual arts for balancing conflicting sensations and moods and for inducing the perception of relative distance in the pictorial plane. While perceptual science has proven quite clearly that the luminance contrast of any hue acts as a self-sufficient cue to relative depth in visual images, the role o...

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...

Similarly shaped letters evoke similar colors in grapheme-color synesthesia.

Science.gov (United States)

Brang, David; Rouw, Romke; Ramachandran, V S; Coulson, Seana

2011-04-01

Grapheme-color synesthesia is a neurological condition in which viewing numbers or letters (graphemes) results in the concurrent sensation of color. While the anatomical substrates underlying this experience are well understood, little research to date has investigated factors influencing the particular colors associated with particular graphemes or how synesthesia occurs developmentally. A recent suggestion of such an interaction has been proposed in the cascaded cross-tuning (CCT) model of synesthesia, which posits that in synesthetes connections between grapheme regions and color area V4 participate in a competitive activation process, with synesthetic colors arising during the component-stage of grapheme processing. This model more directly suggests that graphemes sharing similar component features (lines, curves, etc.) should accordingly activate more similar synesthetic colors. To test this proposal, we created and regressed synesthetic color-similarity matrices for each of 52 synesthetes against a letter-confusability matrix, an unbiased measure of visual similarity among graphemes. Results of synesthetes' grapheme-color correspondences indeed revealed that more similarly shaped graphemes corresponded with more similar synesthetic colors, with stronger effects observed in individuals with more intense synesthetic experiences (projector synesthetes). These results support the CCT model of synesthesia, implicate early perceptual mechanisms as driving factors in the elicitation of synesthetic hues, and further highlight the relationship between conceptual and perceptual factors in this phenomenon. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Color calibration and color-managed medical displays: does the calibration method matter?

Science.gov (United States)

Roehrig, Hans; Rehm, Kelly; Silverstein, Louis D.; Dallas, William J.; Fan, Jiahua; Krupinski, Elizabeth A.

2010-02-01

Our laboratory has investigated the efficacy of a suite of color calibration and monitor profiling packages which employ a variety of color measurement sensors. Each of the methods computes gamma correction tables for the red, green and blue color channels of a monitor that attempt to: a) match a desired luminance range and tone reproduction curve; and b) maintain a target neutral point across the range of grey values. All of the methods examined here produce International Color Consortium (ICC) profiles that describe the color rendering capabilities of the monitor after calibration. Color profiles incorporate a transfer matrix that establishes the relationship between RGB driving levels and the International Commission on Illumination (CIE) XYZ (tristimulus) values of the resulting on-screen color; the matrix is developed by displaying color patches of known RGB values on the monitor and measuring the tristimulus values with a sensor. The number and chromatic distribution of color patches varies across methods and is usually not under user control. In this work we examine the effect of employing differing calibration and profiling methods on rendition of color images. A series of color patches encoded in sRGB color space were presented on the monitor using color-management software that utilized the ICC profile produced by each method. The patches were displayed on the calibrated monitor and measured with a Minolta CS200 colorimeter. Differences in intended and achieved luminance and chromaticity were computed using the CIE DE2000 color-difference metric, in which a value of ▵E = 1 is generally considered to be approximately one just noticeable difference (JND) in color. We observed between one and 17 JND's for individual colors, depending on calibration method and target.

Rising with De Colores: Tapping into the Resources of la Comunidad to Assist Under-Performing Chicano-Latino Students

Science.gov (United States)

Ordonez-Jasis, Rosario; Jasis, Pablo

2004-01-01

This article explores the dynamics and educational potential of De Colores Community Learning Center, an after-school program serving low-performing Chicano-Latino children. The article discusses the foundational characteristics of De Colores and its quest to become a model of empowerment, instead of a more traditional model of service. Finally,…

Analysis of color environment in nuclear power plants

International Nuclear Information System (INIS)

Natori, Kazuyuki; Akagi, Ichiro; Souma, Ichiro; Hiraki, Tadao; Sakurai, Yukihiro.

1996-01-01

This article reports the results of color and psychological analysis of the outlook of nuclear power plants and the visual environments inside of the plants. Study one was the color measurements of the outlook of nuclear plants and the visual environment inside of the plants. Study two was a survey of the impressions on the visual environments of nuclear plants obtained from observers and interviews of the workers. Through these analysis, we have identified the present state of, and the problems of the color environments of the nuclear plants. In the next step, we have designed the color environments of inside and outside of the nuclear plants which we would recommend (inside designs were about fuel handling room, operation floor of turbine building, observers' pathways, central control room, rest room for the operators). Study three was the survey about impressions on our design inside and outside of the nuclear plants. Nuclear plant observers, residents in Osaka city, residents near the nuclear plants, the operators, employees of subsidiary company and the PR center guides rated their impressions on the designs. Study four was the survey about the design of the rest room for the operators controlling the plants. From the results of four studies, we have proposed some guidelines and problems about the future planning about the visual environments of nuclear power plants. (author)

Quantitative measurement of binocular color fusion limit for non-spectral colors.

Science.gov (United States)

Jung, Yong Ju; Sohn, Hosik; Lee, Seong-il; Ro, Yong Man; Park, Hyun Wook

2011-04-11

Human perception becomes difficult in the event of binocular color fusion when the color difference presented for the left and right eyes exceeds a certain threshold value, known as the binocular color fusion limit. This paper discusses the binocular color fusion limit for non-spectral colors within the color gamut of a conventional LCD 3DTV. We performed experiments to measure the color fusion limit for eight chromaticity points sampled from the CIE 1976 chromaticity diagram. A total of 2480 trials were recorded for a single observer. By analyzing the results, the color fusion limit was quantified by ellipses in the chromaticity diagram. The semi-minor axis of the ellipses ranges from 0.0415 to 0.0923 in terms of the Euclidean distance in the u'v´ chromaticity diagram and the semi-major axis ranges from 0.0640 to 0.1560. These eight ellipses are drawn on the chromaticity diagram. © 2011 Optical Society of America

Color segmentation in the HSI color space using the K-means algorithm

Science.gov (United States)

Weeks, Arthur R.; Hague, G. Eric

1997-04-01

Segmentation of images is an important aspect of image recognition. While grayscale image segmentation has become quite a mature field, much less work has been done with regard to color image segmentation. Until recently, this was predominantly due to the lack of available computing power and color display hardware that is required to manipulate true color images (24-bit). TOday, it is not uncommon to find a standard desktop computer system with a true-color 24-bit display, at least 8 million bytes of memory, and 2 gigabytes of hard disk storage. Segmentation of color images is not as simple as segmenting each of the three RGB color components separately. The difficulty of using the RGB color space is that it doesn't closely model the psychological understanding of color. A better color model, which closely follows that of human visual perception is the hue, saturation, intensity model. This color model separates the color components in terms of chromatic and achromatic information. Strickland et al. was able to show the importance of color in the extraction of edge features form an image. His method enhances the edges that are detectable in the luminance image with information from the saturation image. Segmentation of both the saturation and intensity components is easily accomplished with any gray scale segmentation algorithm, since these spaces are linear. The modulus 2(pi) nature of the hue color component makes its segmentation difficult. For example, a hue of 0 and 2(pi) yields the same color tint. Instead of applying separate image segmentation to each of the hue, saturation, and intensity components, a better method is to segment the chromatic component separately from the intensity component because of the importance that the chromatic information plays in the segmentation of color images. This paper presents a method of using the gray scale K-means algorithm to segment 24-bit color images. Additionally, this paper will show the importance the hue

Manifestation of Color in Content and Form of Attar's Lyrics

Directory of Open Access Journals (Sweden)

fatemeh kolahchiyan

2016-12-01

Full Text Available Color is one of the most efficient tools of creating a literary art. Although this element lacks today's diversity in the history of literature, it has always had an important and determining role in inducing concepts to audiences and literary images. Understanding the meaning of different colors used in ancient and modern poetry a groundbreaking attempt to enter the worlds of emotion ad thought of poets and to know the level of their mastery in using literary and form techniques. Given the importance of the subject, the present article is to analyze the function of different colors on content and rhetorical aspect of Attar's lyric; as a follower of Sanaei and pioneer of Rumi, Attar plays a large part in the brightening ancient Persian poetry, including lyricism. Reviewing his lyrics of romance, mysticism, and Qalandar from this from this perspective may lead to understanding another significant dimension of his thought and poems. He mainly uses color to influence meaning and content of romantic poems. The most frequent colors of his poems are: black, red, and green. Simile and irony are the most common techniques he used on this ground

Solution-Grown ZnO Films toward Transparent and Smart Dual-Color Light-Emitting Diode.

Science.gov (United States)

Huang, Xiaohu; Zhang, Li; Wang, Shijie; Chi, Dongzhi; Chua, Soo Jin

2016-06-22

An individual light-emitting diode (LED) capable of emitting different colors of light under different bias conditions not only allows for compact device integration but also extends the functionality of the LED beyond traditional illumination and display. Herein, we report a color-switchable LED based on solution-grown n-type ZnO on p-GaN/n-GaN heterojunction. The LED emits red light with a peak centered at ∼692 nm and a full width at half-maximum of ∼90 nm under forward bias, while it emits green light under reverse bias. These two lighting colors can be switched repeatedly by reversing the bias polarity. The bias-polarity-switched dual-color LED enables independent control over the lighting color and brightness of each emission with two-terminal operation. The results offer a promising strategy toward transparent, miniaturized, and smart LEDs, which hold great potential in optoelectronics and optical communication.

The watercolor illusion and neon color spreading: a unified analysis of new cases and neural mechanisms

Science.gov (United States)

Pinna, Baingio; Grossberg, Stephen

2005-10-01

Coloration and figural properties of neon color spreading and the watercolor illusion are studied using phenomenal and psychophysical observations. Coloration properties of both effects can be reduced to a common limiting condition, a nearby color transition called the two-dot limiting case, which clarifies their perceptual similarities and dissimilarities. The results are explained by the FACADE neural model of biological vision. The model proposes how local properties of color transitions activate spatial competition among nearby perceptual boundaries, with boundaries of lower-contrast edges weakened by competition more than boundaries of higher-contrast edges. This asymmetry induces spreading of more color across these boundaries than conversely. The model also predicts how depth and figure-ground effects are generated in these illusions.

Colored leptons

International Nuclear Information System (INIS)

Harari, H.

1985-01-01

If leptons are composite and if they contain colored preons, one expects the existence of heavy color-octet fermions with quantum numbers similar to those of ordinary leptons. Such a ''colored lepton'' should decay into a gluon and a lepton, yielding a unique experimental signature. Charged ''colored leptons'' probably have masses of the order of the compositeness scale Λ > or approx. 1 TeV. They may be copiously produced at future multi-TeV e + e - , ep and hadron colliders. ''Colored neutrinos'' may have both Dirac and Majorana masses. They could be much lighter than Λ, possibly as light as 100 GeV or less. In such a case they should be readily produced at the CERN anti pp collider, yielding spectacular monojet and dijet events. They may also be produced at LEP and HERA. (orig.)

Mengkaji Penggunaan Software Apple Color untuk Color Grading saat Pasca Produksi

Directory of Open Access Journals (Sweden)

Ahmad Faisal Choiril Anam Fathoni

2011-04-01

Full Text Available In post-production process, there is one process that is not as well known as the video editing process, the addition of animation, special effects enrichment, motion graphics or audio editing and audio mixing, an important process which is rarely realized called Color Correction or Color Grading. Various software have been made to handle this process, ranging from additional filters are already available for free in any editing software, to high-end devices worth billions of dollars dedicated for specifically conducting Color Correction. Apple Color is one of the software included in the purchase of Final Cut Studio package which also include Final Cut Pro for Video Editing, Soundtrack Pro for Sound Editing and Mixing, and Motion for compositing. Apple's Color is specially designed for color correction tasks after previously edited in Final Cut Pro. This paper is designed to introduce Apple's software as well as analyze the feasibility of Apple Color as a professional device in the world of production, especially post-production. Some professional color correction software will be compared briefly with Apple Color to get an objective conclusion. 

Colors in Mind: A Novel Paradigm to Investigate Pure Color Imagery

OpenAIRE

Wantz, Andrea Laura; Borst, Grégoire; Mast, Fred; Lobmaier, Janek

2015-01-01

Mental color imagery abilities are commonly measured using paradigms that involve naming, judging, or comparing the colors of visual mental images of well-known objects (e.g., “Is a sunflower darker yellow than a lemon”?). Although this approach is widely used in patient studies, differences in the ability to perform such color comparisons might simply reflect participants’ general knowledge of object colors rather than their ability to generate accurate visual mental images of the colors of ...

The Disunity of Color

OpenAIRE

Matthen, Mohan

1999-01-01

What is color? What is color vision? Most philosophers answer by reference to humans: to human color qualia, or to the environmental properties or "quality spaces" perceived by humans. It is argued, with reference to empirical findings concerning comparative color vision and the evolution of color vision, that all such attempts are mistaken. An adequate definition of color vision must eschew reference to its outputs in the human cognition and refer only to inputs: color vision consists in...

Fear no colors? Observer clothing color influences lizard escape behavior.

Science.gov (United States)

Putman, Breanna J; Drury, Jonathan P; Blumstein, Daniel T; Pauly, Gregory B

2017-01-01

Animals often view humans as predators, leading to alterations in their behavior. Even nuanced aspects of human activity like clothing color affect animal behavior, but we lack an understanding of when and where such effects will occur. The species confidence hypothesis posits that birds are attracted to colors found on their bodies and repelled by non-body colors. Here, we extend this hypothesis taxonomically and conceptually to test whether this pattern is applicable in a non-avian reptile and to suggest that species should respond less fearfully to their sexually-selected signaling color. Responses to clothing color could also be impacted by habituation to humans, so we examine whether behavior varied between areas with low and high human activity. We quantified the effects of four T-shirt colors on flight initiation distances (FID) and on the ease of capture in western fence lizards (Sceloporus occidentalis), and we accounted for detectability against the background environment. We found no differences in lizard behavior between sites. However, lizards tolerated the closest approaches and were most likely to be captured when approached with the T-shirt that resembled their sexually-selected signaling color. Because changes in individual behavior affect fitness, choice of clothing color by people, including tourists, hikers, and researchers, could impact wildlife populations and research outcomes.

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.