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1

Surface enhanced Raman radiation of crystal violet dye with a SiO2 buffer  

NASA Astrophysics Data System (ADS)

Surface enhanced Raman radiation of crystal violet dye has been studied by modulating the localized surface plasmon effect of silver nanoparticles. In the experiment, a buffer layer of silicon dioxide (SiO2) was established between crystal violet dye and silver nanoparticles. With a probe of laser beam of 532 nm in wavelength, it was found that the intensity of the Raman scattering significantly depended on the thickness of SiO2 layer. A maximum Raman-radiation intensity occurred with a 10nm-thicked SiO2 layer. The experimental observation shows a possible modulation of surface enhanced Raman radiation by a proper dielectric buffer.

Liu, Tung-Kai; Hung, Wen-Chi; Tsai, Ming-Shan; Lo, Chia-Ling; Lin, Yu-Sung; Kuo, Chie-Tong; Jiang, I.-Min

2011-02-01

2

Studies on the utility of plant cellulose waste for the bioadsorption of crystal violet dye.  

PubMed

Several synthetic dyes employed in textile and food industries are discharged into aquatic environment. These visible pollutants in water damage environment, as they are carcinogenic and toxic to humans. The use of cost effective and ecofriendly plant cellulose based adsorbents have been studied in batch experiments as an alternative and effective substitution of activated carbon for the removal of toxic dyes from waste water. Adsorbents prepared from sugarcane baggase, were successfully used to remove certain textile dye such as crystal violet from an aqueous solution. The present investigation potentiate the use of sugarcane baggase, pretreated with formaldehyde (referred as Raw Baggase) and sulphuric acid (referred as Chemically Activated Baggase), for the removal of crystal violet dye from simulated waste water. Experiments were carried out at neutral pH with various parameters like dye concentration, temperature, contact time and adsorbent dosage. Efficiency of raw baggase was found better than chemically activated baggase for adsorption of crystal violet dye. The data obtained perfectly fits in the Freundlich adsorption isotherm. PMID:21046996

Mahesh, S; Kumar, G Vijay; Agrawal, Pushpa

2010-05-01

3

INHIBITING EFFECT OF CRYSTAL VIOLET DYE ON ALUMINUM CORROSION IN ACIDIC AND ALKALINE MEDIA  

Microsoft Academic Search

Crystal violet dye (CV) was studied as a corrosion inhibitor for aluminum in hydrochloric acid (1 mol dm) and potassium hydroxide (0.5 mol dm) solutions in the temperature range 30°–60°C using the gravimetric technique. The effect of iodide ions on the inhibiting efficacy of CV was also assessed. CV was found to inhibit Al corrosion in both aggressive media, exhibiting greater inhibition efficiency

Emeka E. Oguzie

2008-01-01

4

Measuring the Photocatalytic Breakdown of Crystal Violet Dye using a Light Emitting Diode Approach  

NASA Technical Reports Server (NTRS)

A simple method to estimate the photocatalytic reactivity performance of spray-on titanium dioxide coatings for transmissive glass surfaces was developed. This novel technique provides a standardized method to evaluate the efficiency of photocatalytic material systems over a variety of illumination levels. To date, photocatalysis assessments have generally been conducted using mercury black light lamps. Illumination levels for these types of lamps are difficult to vary, consequently limiting their use for assessing material performance under a diverse range of simulated environmental conditions. This new technique uses an ultraviolet (UV) gallium nitride (GaN) light emitting diode (LED) array instead of a traditional black light to initiate and sustain photocatalytic breakdown. This method was tested with a UV-resistant dye (crystal violet) applied to a titanium dioxide coated glass slide. Experimental control is accomplished by applying crystal violet to both titanium dioxide coated slides and uncoated control slides. A slide is illuminated by the UV LED array, at various light levels representative of outdoor and indoor conditions, from the dye side of the slide. To monitor degradation of the dye over time, a temperature-stabilized white light LED, whose emission spectrum overlaps with the dye absorption spectrum, is used to illuminate the opposite side of the slide. Using a spectrometer, the amount of light from the white light LED transmitted through the slide as the dye degrades is monitored as a function of wavelength and time and is subsequently analyzed. In this way, the rate of degradation for photocatalytically coated versus uncoated slide surfaces can be compared. Results demonstrate that the dye absorption decreased much more rapidly on the photocatalytically coated slides than on the control uncoated slides, and that dye degradation is dependent on illumination level. For photocatalytic activity assessment purposes, this experimental configuration and methodology minimizes many external variable effects and enables small changes in absorption to be measured. This research also compares the advantages of this innovative LED light source design over traditional mercury black light systems and non- LED lamp approaches. This novel technology begins to address the growing need for a standard method that can assess the performance of photocatalytic materials before deployment for large scale, real world use.

Ryan, Robert E.; Underwood, Lauren W.; O'Neal, Duane; Pagnutti, Mary; Davis, Bruce A.

2009-01-01

5

Equilibrium, kinetics and mechanism modeling and simulation of basic and acid dyes sorption onto jute fiber carbon: Eosin yellow, malachite green and crystal violet single component systems  

Microsoft Academic Search

Batch experiments were carried out for the sorption of eosin yellow, malachite green and crystal violet onto jute fiber carbon (JFC). The operating variables studied are the initial dye concentration, initial solution pH, adsorbent dosage and contact time. Experimental equilibrium data were fitted to Freundlich, Langmuir and Redlich–Peterson isotherm by non-linear regression method. Langmuir isotherm was found to be the

K. Porkodi; K. Vasanth Kumar

2007-01-01

6

Energy transfer in solid-state dye lasers based on methyl methacrylate co-doped with sulforhodamine B and crystal violet  

NASA Astrophysics Data System (ADS)

Laser action in methyl methacrylate (MMA) co-doped with sulforhodamine B and crystal violet dyes was investigated. The dye mixture was incorporated into a solid polymeric matrix and was pumped by a 532-nm Nd:YAG laser. Distributed feedback dye laser (DFDL) action was induced in the dye mixture using a prism arrangement both in the donor and acceptor regions by an energy transfer mechanism. Theoretically, the characteristics of acceptor and donor DFDLs, and the dependence of their pulse widths and output powers on acceptor—donor concentrations and pump power, were studied. Experimentally, the output energy of DFDL was measured at the emission peaks of donor and acceptor dyes for different pump powers and different acceptor—donor concentrations. Tuning of the output wavelength was achieved by varying the period of the gain modulation of the laser medium. The laser wavelength showed continuous tunability from 563 nm to 648 nm.

Geethu Mani, R. G.; Basheer, Ahamed M.

2013-11-01

7

Triplet-sensitized photobleaching of crystal violet  

Microsoft Academic Search

Crystal violet (CV+) and five related triarylmethane dyes quench triplet benzophenone (3K) in acetonitrile at diffusion-controlled rates (kq ? 1 × 1010 M?1 s?1). The interaction with CV+ results in bleaching of CV+ with a quantum yield, K?(?CV+), dependent on the concentration of CV+ with a limiting value of 0.2 at high [CV+. Benzopinacol (K2H2) is also formed in this

Yousry M. A. Naguib; Colin Steel; Saul G. Cohen; Michael A. Young

1996-01-01

8

IncP-1? plasmids of Comamonas sp. and Delftia sp. strains isolated from a wastewater treatment plant mediate resistance to and decolorization of the triphenylmethane dye crystal violet.  

PubMed

The application of toxic triphenylmethane dyes such as crystal violet (CV) in various industrial processes leads to large amounts of dye-contaminated sludges that need to be detoxified. Specific bacteria residing in wastewater treatment plants (WWTPs) are able to degrade triphenylmethane dyes. The objective of this work was to gain insights into the genetic background of bacterial strains capable of CV degradation. Three bacterial strains isolated from a municipal WWTP harboured IncP-1? plasmids mediating resistance to and decolorization of CV. These isolates were assigned to the genera Comamonas and Delftia. The CV-resistance plasmid pKV29 from Delftia sp. KV29 was completely sequenced. In addition, nucleotide sequences of the accessory regions involved in conferring CV resistance were determined for plasmids pKV11 and pKV36 from the other two isolates. Plasmid pKV29 contains typical IncP-1? backbone modules that are highly similar to those of previously sequenced IncP-1? plasmids that confer antibiotic resistance, degradative capabilities or mercury resistance. The accessory regions located between the conjugative transfer (tra) and mating pair formation modules (trb) of all three plasmids analysed share common modules and include a triphenylmethane reductase gene, tmr, that is responsible for decolorization of CV. Moreover, these accessory regions encode other enzymes that are dispensable for CV degradation and hence are involved in so-far-unknown metabolic pathways. Analysis of plasmid-mediated degradation of CV in Escherichia coli by ultra-high-performance liquid chromatography-electrospray ionization-quadrupole-time-of-flight MS revealed that leuco crystal violet was the first degradation product. Michler's ketone and 4-dimethylaminobenzaldehyde appeared as secondary degradation metabolites. Enzymes encoded in the E. coli chromosome seem to be responsible for cleavage of leuco crystal violet. Plasmid-mediated degradation of triphenylmethane dyes such as CV is an option for the biotechnological treatment of sludges contaminated with these dyes. PMID:22653947

Stolze, Yvonne; Eikmeyer, Felix; Wibberg, Daniel; Brandis, Gerrit; Karsten, Christina; Krahn, Irene; Schneiker-Bekel, Susanne; Viehöver, Prisca; Barsch, Aiko; Keck, Matthias; Top, Eva M; Niehaus, Karsten; Schlüter, Andreas

2012-08-01

9

Biodegradation of crystal violet by the white rot fungus Phanerochaete chrysosporium.  

PubMed Central

Biodegradation of crystal violet (N,N,N',N',N'',N''-hexamethylpararosaniline) in ligninolytic (nitrogen-limited) cultures of the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance of crystal violet and by the identification of three metabolites (N,N,N',N',N''-pentamethylpararosaniline, N,N,N',N''-tetramethylpararosaniline, and N,N',N''-trimethylpararosaniline) formed by sequential N-demethylation of the parent compound. Metabolite formation also occurred when crystal violet was incubated with the extracellular fluid obtained from ligninolytic cultures of this fungus, provided that an H2O2-generating system was supplied. This, as well as the fact that a purified ligninase catalyzed N-demethylation of crystal violet, demonstrated that biodegradation of crystal violet by this fungus is dependent, at least in part, upon its lignin-degrading system. In addition to crystal violet, six other triphenylmethane dyes (pararosaniline, cresol red, bromphenol blue, ethyl violet, malachite green, and brilliant green) were shown to be degraded by the lignin-degrading system of this fungus. An unexpected result was the finding that substantial degradation of crystal violet also occurred in nonligninolytic (nitrogen-sufficient) cultures of P. chrysosporium, suggesting that in addition to the lignin-degrading system, another mechanism exists in this fungus which is also able to degrade crystal violet. PMID:3389809

Bumpus, J A; Brock, B J

1988-01-01

10

Biodegradation of crystal violet by the white rot fungus phanerochaete chrysosporium  

SciTech Connect

Biodegradation of crystal violet (N,N,N',N',N',N''- hexamethylpararosaniline) in ligninolytic (nitrogen-limited) cultures of the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance of crystal violet and by the identification of three metabolites (N,N,N',N',N'' -pentamethylpararosaniline, N,N,N',N'' -tetramethylpararosaniline, and N,N',N'' -trimethylpararosaniline) formed by sequential N-demethylation of the parent compound. Metabolite formation also occurred when crystal violet was incubated with the extracellular fluid obtained from ligninolytic cultures of this fungus, provided that an H2O2-generating system was supplied. This, as well as the fact that a purified ligninase catalyzed N-demethylation of crystal violet, demonstrated that biodegradation of crystal violet by this fungus is dependent, at least in part, upon its lignin-degrading system. In addition to crystal violet, six other triphenylmethane dyes (pararosaniline, cresol red, bromphenol blue, ethyl violet, malachite green, and brilliant green) were shown to be degraded by the lignin-degrading system of this fungus.

Bumpus, J.A.; Brock, B.J.

1988-01-01

11

SERS and DFT study of crystal violet  

NASA Astrophysics Data System (ADS)

Six silver colloids were prepared by the reduction of silver nitrate with different amounts of sodium citrate. The obtained silver colloids were characterised by UV-vis spectroscopy, transmission electron microscopy and zeta potential measurements. The surface-enhanced Raman scattering (SERS) activities of these silver colloids were investigated using crystal violet (CV) as a SERS probe. Based on density functional theory (DFT) calculations at the level of B3LYP, the Raman spectra and the optimised geometry of CV were analysed. The results show that the sodium citrate content strongly influences the sizes, zeta potentials and SERS activities of the silver colloids. As the sodium citrate content increases in the preparation of silver colloids, the mean diameters of the silver nanoparticles decrease. The most intense SERS of CV on the silver colloids is obtained when 3 mL of 1% sodium citrate is used. CV has D3 point group symmetry, and the Raman vibrational modes belong to A1 or E irreducible representations. The non-totally symmetric vibrational modes E are selectively enhanced in the SERS of CV through a Herzberg-Teller vibronic coupling mechanism, indicating a considerable charge transfer between CV and the silver nanoparticles.

Meng, Wei; Hu, Fang; Zhang, Ling-Yan; Jiang, Xiao-Hong; Lu, Lu-De; Wang, Xin

2013-03-01

12

INHIBITION OF LACTIC STREPTOCOCCUS BACTERIOPHAGE BY CRYSTAL VIOLET AND OTHER AGENTS  

PubMed Central

Ninety-nine selected compounds and eleven antibiotic-producing organisms were tested for antiphage activity and host toxicity. A paper disc-agar diffusion method was used for primary screening and quantitative methods were employed for confirmatory investigation. Most of the agents tested, although previously reported as inhibitory to one or more other virus-host systems, did not selectively prevent multiplication of lactic streptococcus bacteriophage. Several compounds which prevented mass lysis were extremely toxic to host bacteria. Crystal violet suppressed growth of two phage strains at a level (1.0 x 10–7 M) which permitted normal growth of the host cells. Failure of crystal violet to prevent multiplication of many phage strains suggested possible variations in the multiplication mechanisms of different strains of virus. Virustatic levels of crystal violet did not destroy unadsorbed virus, reduce adsorption, or prevent invasion; increase of virus was reduced in one-step growth experiments; mass lysis was prevented or delayed in long time experiments. Addition and removal of crystal violet at various intervals during the latent period resulted in virus yields directly related to the portion of the latent period during which no dye was present. Duration of the latent period was unaffected. Single burst experiments indicated that the yield of plaque-forming particles per infected bacterium was reduced; the proportion of infected bacteria giving rise to active progeny did not appear to be influenced to a significant degree. Crystal violet apparently interferes with intracellular multiplication of the virus, possibly by combination of the dye with phage DNA or fractions thereof at some critical stage in the incorporation of DNA into the virus particle. PMID:13084896

Graham, D. M.; Nelson, F. E.

1953-01-01

13

TOXICITY OF AN ANTHRAQUINONE VIOLET DYE MIXTURE FOLLOWING INHALATION EXPOSURE, INTRACHEAL INSTILLATION, OR GAVAGE  

EPA Science Inventory

Anthraquinone dyes in a variety of functions from drug formulations fabric colorative to area markings as might be used of the military. he effects of a prototype violet dye mixture (VDM) consisting of: Disperse Red 11 (DR11) 1,4-diamino-2-methoxy-anthraquinone and Disperse Blue ...

14

[NBI magnifying endoscopic classification using crystal violet staining].  

PubMed

NBI magnifying imaging with crystal violet (CV-NBI magnifying imaging) makes recognition of micro-vascular pattern and grandular structure in the gastric mucosa better. NBI image emphasizes micro-vascular structure in mucosal surface. Magnification endoscopy with crystal violet staining delineates surface grandular structure better than without it. Crystal violet stained epithelium is clearly observed as cobalt green with NBI imaging. In the classification of CV-NBI magnification findings, 71% of differentiated type lesion was classified into ILL (intralobular loop pattern), and the rest (29%) was diagnosed as FNP (fine network pattern) which was originally advocated by Nakayoshi, et al. ILL is the new category of magnifying endoscopy. ILL corresponded mainly to differentiated-type adenocarcinoma, but it also includes undifferentiated-type adenocarcinoma. Corkscrew pattern is corresponding well to undifferentiated-type adnocarcinoma (Nakayoshi, et al). CV-NBI magnifying classification is considered to be related to tissue characterization in gastric cancer. PMID:18464526

Inoue, Haruhiro; Kodama, Kenta; Minami, Hitomi; Wada, Yoshiki; Kaga, Makoto; Sato, Yoshitaka; Sugaya, Satoshi; Kudo, Sinei

2008-05-01

15

Insight into biosorption equilibrium, kinetics and thermodynamics of crystal violet onto Ananas comosus (pineapple) leaf powder  

NASA Astrophysics Data System (ADS)

Biosorption performance of pineapple leaf powder (PLP) for removal of crystal violet (CV) from its aqueous solutions was investigated. To this end, the influence of operational parameters such as pH, biosorbent dose, initial dye concentration and temperature were studied employing a batch experimental setup. The biosorption process followed the Langmuir isotherm model with high correlation coefficients ( R 2 > 0.99) at different temperatures. The maximum monolayer biosorption capacity was found to be 78.22 mg g-1 at 293 K. The kinetic data conformed to the pseudo-second-order kinetic model. The activation energy of the system was calculated as 58.96 kJ mol- 1 , indicating chemisorption nature of the ongoing biosorption process. A thermodynamic study showed spontaneous and exothermic nature of the biosorption process. Owing to its low cost and high dye uptake capacity, PLP has potential for application as biosorbent for removal of CV from aqueous solutions.

Chakraborty, Sagnik; Chowdhury, Shamik; Saha, Papita Das

2012-06-01

16

Non-radiative excitation decay of cresyl violet on TiO 2: variation with dye-surface separation  

NASA Astrophysics Data System (ADS)

Dye-to-surface non-radiative excitation transfer is verified to be an important decay mode for S 1 state cresyl violet separated from a TiO 2 surface by distances between 80 and 509 Å. Fluorescence profiles have also been obtained for cresyl violet adsorbed directly onto TiO 2.

Crackel, Robert L.; Struve, Walter S.

1985-10-01

17

Coherent amplification in fluorescent dye solutions. I. The fluorescence gain spectrum of cresyl violet  

NASA Astrophysics Data System (ADS)

The gain spectrum of cresyl violet has been recorded over the wavelength range 590-650 nm using a synchronously-pumped mode-locked dye laser system. The measured gain spectrum is compared with that calculated using data derived from a conventional absorption spectrum. The value of the polarization techniques developed for measuring orientational and state lifetimes of dye molecules is demonstrated. By locating the probe laser in the spectral region associated with absorption or emission it is shown that it is possible to derive information on the ground or excited electronic states. Fluorescence lifetimes and orientational decay times for cresyl violet in methanol and ethanol are determined for the states S 0 and S 1.

Baran, Jan; Langley, Andrew J.; Jeremy Jones, W.

1984-06-01

18

Antibody labeling with Remazol Brilliant Violet 5R, a vinylsulphonic reactive dye.  

PubMed

Colloidal gold is the first choice for labeling antibodies to be used in Point Of Care Testing. However, there are some recent reports on a family of textile dyes-named "reactive dyes"-being suitable for protein labeling. In the present article, protein labeling conditions were optimized for Remazol Brilliant Violet 5R, and the sensitivity of the labeled antibodies was assessed and compared with that of colloidal-gold labeled antibodies. Also, the accelerated stability was explored. Optimal conditions were pH 10.95, dye:Ab molar ratio of 264 and an incubation time of 132 min. Labeled antibodies were stable, and could be successfully used in a slot blot assay, detecting as low as 400 ng/mL. Therefore, the present work demonstrates that vinylsulphonic reactive dyes can be successfully used to label antibodies, and are excellent candidates for the construction of a new generation of Point of Care Testing kits. PMID:23859783

Ferrari, Alejandro; Friedrich, Adrián; Weill, Federico; Wolman, Federico; Leoni, Juliana

2013-01-01

19

Fast analysis of malachite green, leucomalachite green, crystal violet and leucocrystal violet in fish tissue based on a modified QuEChERS procedure.  

PubMed

Triphenylmethane dyes malachite green (MG) and crystal violet (CV) have been used as antimicrobial, antiparasitic and antiseptic agents in aquaculture. However, MG and CV, as well as their metabolites leucomalachite green (LMG) and leucocrystal violet (LCV) are potential mutagens and carcinogens. Thus, the efficient determination of dye residues is of great concern. Considering the complexity of the aquatic products, the sample pretreatment is significant for decreasing matrix interference and improving detection sensitivity. In this study, a simple and rapid QuEChERS procedure was developed and combined with HPLC analysis for the simultaneous determination of the four dyes in fish tissue. An XCharge C18 column was applied in HPLC analysis to achieve good peak shape and selectivity. The pretreatment method involved the extraction of dyes from fish tissue and further clean-up with dispersive solid phase extraction (d-SPE) material. The extraction volume, extraction time as well as d-SPE materials were systematically optimized. The results indicated that reversed-phase/strong anion exchange (C18SAX) adsorbent in the d-SPE procedure could effectively improve the recovery compared with conventional C18 or C18 incorporated with primary secondary amine (PSA) material. Under optimized conditions, good linearity was achieved in the concentration range of 0.5-100 mg/L with R2 greater than 0. 998. The recoveries were 73%-91% and the precisions were 0.66%-5.41%. The results demonstrated the feasibility and efficiency of QuEChERS procedure incorporated with HPLC for dye monitoring. PMID:25069333

Zhu, Chengyun; Wei, Jie; Dong, Xuefang; Guo, Zhimou; Liu, Mingyang; Liang, Xinmiao

2014-04-01

20

Batch Removal of Crystal Violet from Aqueous Solution by H2SO4 Modified Sugarcane Bagasse: Equilibrium, Kinetic, and Thermodynamic Profile  

Microsoft Academic Search

Batch adsorption studies were carried out using H2SO4 modified sugarcane bagasse (HMSB) for the removal of hazardous Crystal Violet (CV) dye from aqueous solutions. The effects of initial solution pH, adsorbent dose, and temperature on the adsorption process were investigated. The Langmuir isotherm model well described the equilibrium dye uptake while the pseudo-second-order kinetic model showed good agreement with the

Sagnik Chakraborty; Shamik Chowdhury; Papita Das Saha

2012-01-01

21

Batch Removal of Crystal Violet From Aqueous Solution by H2SO4 Modified Sugarcane Bagasse: Equilibrium, Kinetic and Thermodynamic Profile  

Microsoft Academic Search

Batch adsorption studies were carried out using H2SO4 modified sugarcane bagasse (HMSB) for removal of hazardous Crystal Violet (CV) dye from aqueous solutions. Effects of initial solution pH, adsorbent dose and temperature on the sorption process were investigated. The Langmuir isotherm model well described the equilibrium dye uptake while the pseudo-second-order kinetic model showed good agreement with the experimental kinetic

Sagnik Chakraborty; Shamik Chowdhury; Papita Das Saha

2012-01-01

22

Vibrational spectroscopic studies on the dyes cresyl violet and coumarin 152  

NASA Astrophysics Data System (ADS)

Infrared, Raman and SERS spectra of two cationic dyes—cresyl violet perchlorate and coumarin 152—were measured. Density function theory calculations were performed in order to support the vibrational spectra assignment. The data obtained indicate that cresyl violet is weakly physisorbed on the silver surface. The molecule is attached to the metal in a "vertical" configuration with its molecular plane perpendicular to the surface. Both amino groups of the molecule are in proximity to the metal surface. Coumarin 152 interacts with the silver surface through the carbonyl group. The C?O bond is weakened by the adsorption. The interaction with the metal also influences the adjacent double bonds in the lactone ring. Coumarin 152 is bonded to silver in a "vertical" configuration with its molecular plane perpendicular to the surface as well.

Vogel, E.; Gbureck, A.; Kiefer, W.

2000-09-01

23

BIODEGRADATION OF CRYSTAL VIOLET BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOPORIUM  

EPA Science Inventory

Biodegradation of crystal violet (N,N,N',N',N",N"-hexamethylpararosaniline) in ligninolytic (nitrogen-limited) cultures of the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance of crystal violet and by the identification of three metabolites (N,N,...

24

Photonic crystal reflectance switching by dye electrophoresis  

NASA Astrophysics Data System (ADS)

Reflectivity of a photonic crystal device fabricated by glancing angle deposition may be reversibly altered by infiltration with an absorbing dye solution. An electric field controls the dye ion motion through the photonic crystal. Rapid reflectance changes up to 0.4 in the crystal's optical band gap are demonstrated. The time evolution of the dye movement process is examined and its operation described. This work may have applications for a passive optical display.

Krabbe, Joshua D.; Brett, Michael J.

2010-07-01

25

Synthesis of CarAlg/MMt nanocomposite hydrogels and adsorption of cationic crystal violet.  

PubMed

CarAlg/MMt nanocomposite hydrogels composed of kappa-carrageenan (Car) and sodium alginate (Alg) biopolymers were synthesized by incorporation of sodium montmorillonite (Na-MMt) nanoclay. Acrylamide (AAm), methylenebisacrylamide (MBA), and ammonium persulfate (APS) were used as monomer, crosslinker, and initiator, respectively. The structure and morphology of nanocomposites were characterized by XRD, SEM, and TEM techniques. The XRD results showed exfoliated MMt nanoclay and exfoliation of MMt was confirmed by TEM graph. The resulting nanocomposites were evaluated to remove cationic crystal violet (CV) dye from water. According to data, the adsorption capacity of nanocomposites was enhanced as the clay content was increased. The experimental data were analyzed according to both Langmuir and Freundlich models and experimental maximum adsorption capacity was obtained 88.8 mg g(-1). By studying the effect of pH on the dye adsorption capacity of nanocomposites, it was revealed that the adsorption capacity of nanocomposites was enhanced at acidic pHs as the Na-MMt nanoclay and kappa-carrageenan components were increased. PMID:23987355

Mahdavinia, Gholam Reza; Aghaie, Huriyeh; Sheykhloie, Hossein; Vardini, Mohammad Taghi; Etemadi, Hossein

2013-10-15

26

Catalytic Activity of Biomorphic ?-MoO3 in the Degradation of Methyl Violet Dye  

PubMed Central

Abstract A network of fibers comprising orthorhombic molybdenum trioxide (?-MoO3) crystals were synthesized using paper as template via a biomorphic approach. The template was completely removed by annealing the sample at 600°C for 5?min. Monoclinic MoO3 was formed and consequently converted into orthorhombic ?-MoO3 after prolonged annealing. Three milligrams of the biomorphic ?-MoO3 could degrade up to 90% of a methyl violet aqueous solution with a concentration of 20?mg/L under normal visible light. The size of the ?-MoO3 grains and the porosity of the biomorphic sample affected catalytic performance. PMID:22969268

Diao, Zhenyu; Kwong, Fung-Luen; Li, Jia; Lian, Jiabiao; Lai, Kwing-To; Ng, Dickon H.L.

2012-01-01

27

Molecular Spectra and Optical Relaxation of Oxazine Dyes Nile Blue and Cresyl Violet.  

NASA Astrophysics Data System (ADS)

Using fluorescence-line-narrowing and hole-burning techniques I obtain molecular spectra of the oxazine dye nile blue at 5 K under a wide range of experimental conditions. These data are analyzed by constructing a single site molecular lineshape function and the corresponding 0-0 transition frequency distribution which, taken together, enable me to explain the various results. I also perform time-delayed-four-wave-mixing experiments (TDFWM) on nile blue and cresyl violet at 5 K using incoherent laser radiation. The response depends dramatically on the bandwidth and frequency of the radiation source. Fast (femtosecond) and slow (picosecond) processes, variable peak shifts, and type I and II quantum beats are observed in varying degrees according to the character of the laser excitation. I calculate the TDFWM response of nile blue on the basis of the single site lineshape function and the inhomogeneous distribution function with information from fluorescence-line-narrowing and hole-burning experiments and find that I can explain the wide range of behavior observed here. TDFWM experiments are also carried out on nile blue and cresyl violet at room temperature, using an intense incoherent laser. The response contains a modulated component which bears no relation to the dyes' energy level structures. I explain the observed modulation as a result of a destructive interference between induced high order polarizations. This modulation is a consequence of irradiating the sample at high intensities and, in contrast to modulation arising from quantum beats, disappears when the intensity of the laser excitation is reduced.

Zhang, Yiping

1995-01-01

28

Fixed-bed column studies on biosorption of crystal violet from aqueous solution by Citrullus lanatus rind and Cyperus rotundus  

NASA Astrophysics Data System (ADS)

In this study, fixed-bed column experiments were performed to investigate the biosorption potential of two agricultural wastes, Citrullus lanatus rind and Cyperus rotundus to remove Crystal violet (CV) from aqueous solution. The experiments were conducted to study the effects of important parameters such as bed depth (10-30 cm), flow rate (10-20 mL min-1) and initial dye concentration (10-25 mg L-1). Different models like Bed Depth Service Time (BDST) model, Thomas model and Yoon-Nelson model were applied to the experimental sorption data. In the biosorption of Crystal violet by both the sorbents, the BDST model fitted well with the experimental data in the initial region of the breakthrough curve. Also, Yoon-Nelson model was found to show good agreement with the experimental kinetic results as compared to the Thomas model. The sorbents were found to be very potential, as it showed good sorption capacities of 46.68 and 54.24 mg g-1 for CV biosorption by Citrullus lanatus rind and Cyperus rotundus. Recovery of dye was made by eluting 1 N CH3COOH through the exhausted column in downward direction.

Bharathi, Kandaswamy Suyamboo; Ramesh, SriKrishna Perumal Thanga

2013-12-01

29

Isolation and Characterization of Paracoccus sp. GSM2 Capable of Degrading Textile Azo Dye Reactive Violet 5  

PubMed Central

A potential bacterial strain GSM2, capable of degrading an azo dye Reactive Violet 5 as a sole source of carbon, was isolated from textile mill effluent from Solapur, India. The 16S rDNA sequence and phenotypic characteristics indicated an isolated organism as Paracoccus sp. GSM2. This strain exhibited complete decolorization of Reactive Violet 5 (100?mg/L) within 16?h, while maximally it could decolorize 800?mg/L of dye within 38 h with 73% decolorization under static condition. For color removal, the most suitable pH and temperature were pH 6.0–9.0 and 25–40°C, respectively. The isolate was able to decolorize more than 70% of five structurally different azo dyes within 38 h. The isolate is salt tolerant as it can bring out more than 90% decolorization up to a salt concentration of 2% (w/v). UV-Visible absorption spectra before and after decolorization suggested that decolorization was due to biodegradation and was further confirmed by FT-IR spectroscopy. Overall results indicate the effectiveness of the strain GSM2 explored for the treatment of textile industry effluents containing various azo dyes. To our knowledge, this could be the first report on biodegradation of Reactive Violet 5 by Paracoccus sp. GSM2. PMID:24883397

Bheemaraddi, Mallikarjun C.; Shivannavar, Channappa T.; Gaddad, Subhashchandra M.

2014-01-01

30

[Active carbon from Thalia dealbata residues: its preparation and adsorption performance to crystal violet].  

PubMed

By using phosphoric acid as activation agent, active carbon was prepared from Thalia dealbata residues. The BET specific surface area of the active carbon was 1174.13 m2 x g(-1), micropore area was 426.99 m2 x g(-1), and average pore diameter was 3.23 nm. An investigation was made on the adsorption performances of the active carbon for crystal violet from aqueous solution under various conditions of pH, initial concentration of crystal violet, contact time, and contact temperature. It was shown that the adsorbed amount of crystal violet was less affected by solution pH, and the adsorption process could be divided into two stages, i. e., fast adsorption and slow adsorption, which followed the pseudo-second-order kinetics model. At the temperature 293, 303, and 313 K, the adsorption process was more accordance with Langmuir isotherm model, and the maximum adsorption capacity was 409.83, 425.53, and 438.59 mg x g(-1), respectively. In addition, the adsorption process was spontaneous and endothermic, and the randomness of crystal violet molecules increased. PMID:24066559

Chu, Shu-Yi; Yang, Min; Xiao, Ji-Bo; Zhang, Jun; Zhu, Yan-Ping; Yan, Xiang-Jun; Tian, Guang-Ming

2013-06-01

31

Modification of the photocatalytic activity of TiO2 by ?-Cyclodextrin in decoloration of ethyl violet dye  

PubMed Central

The photocatalytic decoloration of an organic dye, ethyl violet (EV), has been studied in the presence of TiO2 and the addition of ?-Cyclodextrin (?-CD) with TiO2 (TiO2-?-CD) under UV-A light irradiation. The different operating parameters like initial concentration of dye, illumination time, pH and amount of catalyst used have also been investigated. The photocatalytic decoloration efficiency is more in the TiO2-?-CD/UV-A light system than TiO2/UV-A light system. The mineralization of EV has been confirmed by Chemical Oxygen Demand (COD) measurements. The complexation patterns have been confirmed with UV–Visible and FT-IR spectral data and the interaction between TiO2 and ?-CD have been characterized by powder XRD analysis and UV–Visible diffuse reflectance spectroscopy. PMID:25685468

Velusamy, Ponnusamy; Pitchaimuthu, Sakthivel; Rajalakshmi, Subramanian; Kannan, Nagarathinam

2012-01-01

32

Batch and continuous (fixed-bed column) biosorption of crystal violet by Artocarpus heterophyllus (jackfruit) leaf powder.  

PubMed

In this study, batch and fixed-bed column experiments were performed to investigate the biosorption potential of Artocarpus heterophyllus (jackfruit) leaf powder (JLP) to remove crystal violet (CV) from aqueous solutions. Batch biosorption studies were carried out as a function of solution pH, contact time, initial dye concentration and temperature. The biosorption equilibrium data showed excellent fit to the Langmuir isotherm model with maximum monolayer biosorption capacity of 43.39 mg g(-1) at pH 7.0, initial dye concentration=50 mg L(-1), temperature=293 K and contact time=120 min. According to Dubinin-Radushkevich (D-R) isotherm model, biosorption of CV by JLP was chemisorption. The biosorption kinetics followed the pseudo-second-order kinetic model. Thermodynamic analysis revealed that biosorption of CV from aqueous solution by JLP was a spontaneous and exothermic process. In order to ascertain the practical applicability of the biosorbent, fixed-bed column studies were also performed. The breakthrough time increased with increasing bed height and decreased with increasing flow rate. The Thomas model as well as the BDST model showed good agreement with the experimental results at all the process parameters studied. It can be concluded that JLP is a promising biosorbent for removal of CV from aqueous solutions. PMID:22221460

Saha, Papita Das; Chakraborty, Sagnik; Chowdhury, Shamik

2012-04-01

33

Loss of crystal violet binding activity in stationary phase Yersinia enterocolitica following gamma irradiation  

Microsoft Academic Search

Ionizing radiation can eliminate virulent Yersinia enterocolitica from meat. It is possible, however unlikely, that a small number of Y. enterocolitica could survive the pasteurization process. The virulence ofY. enterocolitica is dependent upon the presence of a 70 kb plasmid. The effect of low-dose ionizing radiation on the plasmid-associated virulence trait of crystal violet binding was investigated. Y. enterocolitica strains

Christopher H. Sommers; Saumya Bhaduri

2001-01-01

34

Effectiveness of photochemical and sonochemical processes in degradation of Basic Violet 16 (BV16) dye from aqueous solutions  

PubMed Central

In this study, degradation of Basic Violet 16 (BV16) by ultraviolet radiation (UV), ultrasonic irradiation (US), UV/H2O2 and US/H2O2 processes was investigated in a laboratory-scale batch photoreactor equipped with a 55W immersed-type low-pressure mercury vapor lamp and a sonoreactor with high frequency (130kHz) plate type transducer at 100W of acoustic power. The effects of initial dye concentration, concentration of H2O2 and solution pH and presence of Na2SO4 was studied on the sonochemical and photochemical destruction of BV16 in aqueous phase. The results indicated that in the UV/H2O2 and US/H2O2 systems, a sufficient amount of H2O2 was necessary, but a very high H2O2 concentration would inhibit the reaction rate. The optimum H2O2 concentration was achieved in the range of 17 mmol/L at dye concentration of 30 mg/L. A degradation of 99% was obtained with UV/H2O2 within 8 minutes while decolorization efficiency by using UV (23%), US (<6%) and US/H2O2(<15%) processes were negligible for this kind of dye. Pseudo-first order kinetics with respect to dyestuffs concentrations was found to fit all the experimental data. PMID:23369268

2012-01-01

35

Effectiveness of photochemical and sonochemical processes in degradation of Basic Violet 16 (BV16) dye from aqueous solutions.  

PubMed

In this study, degradation of Basic Violet 16 (BV16) by ultraviolet radiation (UV), ultrasonic irradiation (US), UV/H2O2 and US/H2O2 processes was investigated in a laboratory-scale batch photoreactor equipped with a 55W immersed-type low-pressure mercury vapor lamp and a sonoreactor with high frequency (130kHz) plate type transducer at 100W of acoustic power. The effects of initial dye concentration, concentration of H2O2 and solution pH and presence of Na2SO4 was studied on the sonochemical and photochemical destruction of BV16 in aqueous phase. The results indicated that in the UV/H2O2 and US/H2O2 systems, a sufficient amount of H2O2 was necessary, but a very high H2O2 concentration would inhibit the reaction rate. The optimum H2O2 concentration was achieved in the range of 17 mmol/L at dye concentration of 30 mg/L. A degradation of 99% was obtained with UV/H2O2 within 8 minutes while decolorization efficiency by using UV (23%), US (<6%) and US/H2O2(<15%) processes were negligible for this kind of dye. Pseudo-first order kinetics with respect to dyestuffs concentrations was found to fit all the experimental data. PMID:23369268

Rahmani, Zahra; Kermani, Majid; Gholami, Mitra; Jafari, Ahmad Jonidi; Mahmoodi, Niyaz Mohammad

2012-01-01

36

Burkholderia vietnamiensis C09V as the functional biomaterial used to remove crystal violet and Cu(II).  

PubMed

Burkholderia vietnamiensis C09V (B.V. C09V) was used to remove both crystal violet (CV) and Cu(II) because dye effluents often contain dyes and metal ions. Inhibiting the strain?s growth through the biosorption of Cu(II) on B.V. C09V and promoting its growth by using CV as a carbon source led to the degradation of CV (30mg/L). It fell to 36.9 percent and the amount of Cu(II) (50mg/L) removed rose to 34.9 percent in the presence of both CV and Cu(II). This outcome is comparable to the single presence of CV and Cu(II). EDS analysis showed that Cu(II) was adsorbed onto the strain (the atomic percentage of Cu(II) was 1.9 percent), while kinetic studies indicated that firstly, the decolorization of CV fitted well to the pseudo first-order degradation kinetic model and secondly, the biosorption of Cu(II) fitted well to the pseudo second-order kinetic model. The degradation rate constants of CV were stable in the 0.101-0.0068/h range and R(2) was both higher than 0.981 when Cu(II) concentrations were present. Furthermore, the biosorption capacity of Cu(II) ranged from 38.8 to 20.3mg/g at the CV concentration of 30mg/L (both R(2)>0.96). This suggests that the strain has the potential to degrade CV and facilitate the biosorption of Cu(II) in dye effluent. PMID:24780226

Zhou, Fengfei; Cheng, Ying; Gan, Li; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

2014-07-01

37

Determination of crystal violet in water by direct solid phase spectrophotometry after rotating disk sorptive extraction.  

PubMed

The microextraction of crystal violet (CV) from water samples into polydimethylsiloxane (PDMS) using the rotating disk sorptive extraction (RDSE) technique was performed. The extracting device was a small Teflon disk that had an embedded miniature magnetic stirring bar and a PDMS (560 ?L) film attached to one side of the disk using double-sided tape. The extraction involves a preconcentration of CV into the PDMS, where the analyte is then directly quantified using solid phase spectrophotometry at 600 nm. Different chemical and extraction device-related variables were studied to achieve the best sensitivity for the determination. The optimum extraction was performed at pH 14 because under this condition, CV is transformed to the neutral and colorless species carbinol, which can be quantitatively transferred to the PDMS phase. Although the colorless species is the chemical form extracted in the PDMS, an intense violet coloration appeared in the phase because the -OH bond in the carbinol molecule is weakened through the formation of hydrogen bonds with the oxygen atoms of the PDMS, allowing the resonance between the three benzene rings to compensate for the charge deficit on the central carbon atom of the molecule. The accuracy and precision of the method were evaluated in river water samples spiked with 10 and 30 ?g L(-1) of CV, yielding a relative standard deviation of 6.2% and 8.4% and a recovery of 98.4% and 99.4%, respectively. The method detection limit was 1.8 ?g L(-1) and the limit of quantification was 5.4 ?g L(-1), which can be decreased if the sample volume is increased. PMID:23598132

Manzo, Valentina; Navarro, Orielle; Honda, Luis; Sánchez, Karen; Inés Toral, M; Richter, Pablo

2013-03-15

38

Live cell cycle analysis of Drosophila tissues using the Attune Acoustic Focusing Cytometer and Vybrant DyeCycle violet DNA stain.  

PubMed

Flow cytometry has been widely used to obtain information about DNA content in a population of cells, to infer relative percentages in different cell cycle phases. This technique has been successfully extended to the mitotic tissues of the model organism Drosophila melanogaster for genetic studies of cell cycle regulation in vivo. When coupled with cell-type specific fluorescent protein expression and genetic manipulations, one can obtain detailed information about effects on cell number, cell size and cell cycle phasing in vivo. However this live-cell method has relied on the use of the cell permeable Hoechst 33342 DNA-intercalating dye, limiting users to flow cytometers equipped with a UV laser. We have modified this protocol to use a newer live-cell DNA dye, Vybrant DyeCycle Violet, compatible with the more common violet 405nm laser. The protocol presented here allows for efficient cell cycle analysis coupled with cell type, relative cell size and cell number information, in a variety of Drosophila tissues. This protocol extends the useful cell cycle analysis technique for live Drosophila tissues to a small benchtop analyzer, the Attune Acoustic Focusing Cytometer, which can be run and maintained on a single-lab scale. PMID:23712023

Flegel, Kerry; Sun, Dan; Grushko, Olga; Ma, Yiqin; Buttitta, Laura

2013-01-01

39

Adsorption of basic dyes from aqueous solution onto pumice powder  

Microsoft Academic Search

The adsorption of methylene blue and crystal violet on pumice powder samples of varying compositions was investigated using a batch adsorption technique. The effects of various experimental parameters, such as adsorbent dosage, initial dye concentration, and contact time, were also investigated. The extent of dye removal increased with decreased initial concentration of the dye and also increased with increased contact

Feryal Akbal

2005-01-01

40

Determination of polyhexamethylene biguanide hydrochloride using photometric colloidal titration with crystal violet as a color indicator.  

PubMed

A solution of polyhexamethylene biguanide hydrochloride (PHMB-HCl) was titrated with a standard solution of potassium poly(vinyl sulfate) (PVSK) using crystal violet (CV) as an photometric indicator cation. The end point was detected by a sharp absorbance change due to an abrupt decrease in the concentration of CV. A linear relationship between the concentration of PHMB-HCl and the end-point volume of the titrant existed in the concentration range from 2 to 10 × 10(-6) eq mol L(-1). Back-titration was based on adding an excess amount of PVSK to a sample solution containing CV, which was titrated with a standard solution of poly(diallyldimethylammonium chloride) (PDADMAC). The calibration curve of the PHMB-HCl concentration to the end point volume of the titrant was also linear in the concentration range from 2 to 8 × 10(-6) eq mol L(-1). Both photometric titrations were applied to the determination of PHMB-HCl in a few contact-lens detergents. Back-titration showed a clear end point, but direct titration showed an unclear end point. The results of the back-titration of PHMB-HCl were compared with the content registered in its labels. PMID:21828919

Masadome, Takashi; Miyanishi, Takaaki; Watanabe, Keita; Ueda, Hiroshi; Hattori, Toshiaki

2011-01-01

41

Quenching of fluorescence by crystal violet and its use to differentiate between surface-bound and internalized bacteria  

NASA Astrophysics Data System (ADS)

Phagocytosis is a complex process involving attachment, ingestion and intracellular processing of bacteria by phagocytes. A great difficulty in the evaluation of this process is to differentiate between attachment of the particles to the cell surface and internalization of the particles by the cells. Various techniques have been used to differentiate internalized and surface-attached bacteria in cultured cells, but only a few permit differentiations between surface-bound and internalized bacteria. In this study the quenching of fluorescence by crystal violet on acridine orange stained bacterial biofilm and planktonic bacterial cells is used to differentiate between surface-bound and internalized bacteria within macrophages. Method: One week old Enterococcus faecalis biofilm was grown on perspex and glass substrates in All-Culture medium (nutrient-rich condition) and phosphate buffered saline (nutrient-deprived condition). As model systems, human monocytic (THP-1) and histiocytic (U937) cell lines were used. These cell lines were incubated with the biofilm bacteria for 4 hrs in CO II incubator at 37 °C. The cells and bacteria were stained with acridine orange and quenched with crystal violet to distinguish between surface-bound and internalized bacteria. Results: The presence of green-fluorescing internalized bacteria was detected within the macrophages under the planktonic, nutrient-rich and nutrient-deprived biofilm conditions. All infecting bacteria take up acridine orange and fluoresced green, crystal violet quenched the fluorescence of extra-cellular adhering bacteria so that only fluorescent intracellular bacteria would be visible under fluorescent light microscopy.

Mathew, S.; Lim, Y. C.; Kishen, A.

2008-06-01

42

Application of LC-MS and LC-MS-MS to the analysis of photo-decomposed crystal violet in the investigation of cultural heritage materials aging.  

PubMed

In this work, the accurate liquid chromatography-ultraviolet-visible (LC-UV-Vis), LC-mass spectrometry (MS) and LC-MS-MS analysis of the photo-degradation products of crystal violet (CV) is reported. CV is a light fugitive early synthetic dye which had a widespread diffusion into the market starting from the end of the XIX century and was used among others by V. Van Gogh and P. Gauguin in their writings, drawings or paintings. On-line photodiode array detector enabled simultaneous UV-Vis spectra acquisition. Many degradation compounds were identified through their exact mass (2?ppm accuracy) and MS-MS technique. In particular, all CV demethylated products, demethylated Michler's ketone and particularly some compounds that most likely contain oxygen, such as N-oxides, were found. Fragmentation products are all justified by the proposed fragmentation scheme, in term of precursor exact mass and isotopic profile, characteristic losses in fragmentation and rebuilt structure formula. In particular, we hypothesized the presence of N-imido oxides and hydroxylamine derivates, never reported before, together with the demethylated derivatives of the studied dyes. All these compounds, although at trace level in our samples, contribute to the discoloration and fading of works of arts made with CV. In particular, demethylation of CV by UV light leads to formation of compounds absorbing at shorter wavelengths than CV (blue shift) or no-absorbing in visible range (yellow-colourless) with an overall effect that may appear reddish-brown. This phenomenon justifies drawings appearing grey or brown on aged yellowed paper, when CV-based inks or paints were used. The final aim was to better characterize the photo-degradation of early synthetic dyes (in particular of CV) and to gain a better insight into the discoloration and fading of purple ink strokes made of CV. PMID:23280755

Favaro, Gabriella; Confortin, Daria; Pastore, Paolo; Brustolon, Marinarosa

2012-12-01

43

Molecular mechanisms and binding site location for the noncompetitive antagonist crystal violet on nicotinic acetylcholine receptors.  

PubMed

We investigated the molecular mechanisms and the binding site location for the fluorophor crystal violet (CrV), a noncompetitive antagonist of the nicotinic acetylcholine receptor (AChR). To this end, radiolabeled competition binding, fluorescence spectroscopy, Schild-type analysis, patch-clamp recordings, and molecular dynamics approaches were used. The results indicate that (i) CrV interacts with the desensitized Torpedo AChR with higher affinity than with the resting state at several temperatures (5-37 degrees C); (ii) CrV-induced inhibition of the phencyclidine (PCP) analogue [(3)H]thienylcyclohexylpiperidine binding to the desensitized or resting AChR is mediated by a steric mechanism; (iii) tetracaine inhibits CrV binding to the resting AChR, probably by a steric mechanism; (iv) barbiturates modulate CrV binding to the resting AChR by an allosteric mechanism; (v) CrV itself induces AChR desensitization; (vi) CrV decreases the peak of macroscopic currents by acting on the resting AChR but without affecting the desensitization rate from the open state; and (vii) two tertiary amino groups from CrV may bind to the alpha1-Glu(262) residues (located at position 20') in the resting state. We conclude that the CrV binding site overlaps the PCP locus in the resting and desensitized state. The noncompetitive action of CrV may be explained by an allosteric mechanism in which the binding of CrV to the extracellular mouth of the resting receptor leads to an inhibition of channel opening. Binding of CrV probably increases desensitization of the resting channel and stabilizes the desensitized state. PMID:16475790

Arias, Hugo R; Bhumireddy, Pankaj; Spitzmaul, Guillermo; Trudell, James R; Bouzat, Cecilia

2006-02-21

44

Effects of sonochemical parameters and inorganic ions during the sonochemical degradation of crystal violet in water.  

PubMed

This work deals with the ultrasonic degradation (800 kHz) of crystal violet (CV) under different experimental conditions. The effects of saturating gas (argon, carbon dioxide and air), CV concentration (2.45-1225 ?mol L(-1)), pH (3-9) and power (20-80 W) were evaluated. The best performances were obtained at 80 W with argon as a saturating gas. The pH had no significant effect. The influence of several water matrices containing anions (chloride, sulphate and bicarbonate) and cations (Fe(2+)) on the sonolytic degradation of CV was also investigated. Significant differences were not observed with the presence of chloride and sulphate. However, at relatively low pollutant concentration (2.45 ?mol L(-1)) bicarbonate showed a particular effect: a high bicarbonate concentration (350 mmol L(-1)) produced a detrimental effect, while a low bicarbonate concentration (3 mmol L(-1)) increased the efficiency of the process. The presence of Fe(2+) (1 mmol L(-1)) also increased the CV (49 ?mol L(-1)) degradation by 32% after 180 min. Analyses of intermediates by GC-MS led to the identification of several sonochemical by-products: N,N-dimethylaminobenzene, 4-(N,N-dimethylamino)-4'-(N',N'-dimethylamino)benzophenone, and N,N,N',N'-tetramethyl-4,4'-diaminodiphenylmethane. The presence of these aromatic structures showed that the main ultrasonic CV degradation pathway is linked to the reaction with *OH radicals. At the end of the treatment, these early products were converted into biodegradable organic by-products which could be easily treated in a subsequent biological treatment. PMID:20797896

Guzman-Duque, Fernando; Pétrier, Christian; Pulgarin, Cesar; Peñuela, Gustavo; Torres-Palma, Ricardo A

2011-01-01

45

Aggregation behavior and chromonic liquid crystal properties of an anionic monoazo dye Viva R. Horowitz,1  

E-print Network

Aggregation behavior and chromonic liquid crystal properties of an anionic monoazo dye Viva R the aggregation process and chromonic liquid crystal phase of the anionic monoazo dye Sunset Yellow FCF. The x undergoing a phase transition to an orientationally ordered chromonic liquid crystal phase at high dye

Collings, Peter

46

Photonic crystal switching by the electrophoretic movement of dye ions  

NASA Astrophysics Data System (ADS)

Glancing angle deposition (GLAD) facilitates the fabrication of nanostructured thin films with varying density, using a motion control algorithm governing substrate movements during film growth, which engineerings the film structure. Film architectures for specific optical applications including photonic crystals are easily produced with GLAD. A challenge in the photonic crystal field has been the realization of in-situ control of optical characteristics. We have demonstrated partial control of stopband optical characteristics using an electric field in a GLAD 1D photonic crystal by the electrophoretic movement of absorbing dye ions.

Krabbe, Joshua D.; Brett, Michael J.

2010-02-01

47

Optically switchable gratings based on azo-dye-doped, polymer-dispersed liquid crystals  

E-print Network

Optically switchable gratings based on azo-dye-doped, polymer-dispersed liquid crystals Yan Jun Liu, optically switchable grating using azo-dye-doped, polymer-dispersed liquid crystals (LCs). Our experiments.1150. Holographic polymer-dispersed liquid crystals (H-PDLCs) [1] have been developed for a wide range of photonic

48

Photoluminescence analysis of self induced planer alignment in azo dye dispersed nematic liquid crystal complex  

SciTech Connect

We have developed azo dye doped nematic liquid crystal complex for advanced photonic liquid crystal display technology aspects. Disperse orange azo dye self introduced planer alignment in the nematic liquid crystal without any surface anchoring treatment. Planer alignment was characterized by optical polarizing microscopy. The electro-optical switching response of dye disperse planer aligned nematic cell was investigated as a function of applied voltage with the help of photoluminescence spectrophotometer for the tuning of photoluminescence contrast.

Kumar, Rishi, E-mail: kkraina@gmail.com; Sood, Srishti, E-mail: kkraina@gmail.com; Raina, K. K., E-mail: kkraina@gmail.com [School of Physics and Materials Science, Thapar University, Patiala-147004 (India)

2014-04-24

49

Efficient degradation of crystal violet in magnetic CuFe2O4 aqueous solution coupled with microwave radiation.  

PubMed

Nanoscale copper ferrite was prepared by co-precipitation method, while citrate acid assisted method was used as reference. Microwave-induced degradation of crystal violet was performed with synthesized copper ferrite, and the behavior of copper ferrite in this process was studied by X-ray photoelectron spectroscopy, SEM/EDS and vector network analyzer. Microwave radiation could greatly enhance the activity of copper ferrite in organic oxidation. The variant of copper and iron on the surface and in the inner core of copper ferrite was studied here. Copper ferrite presents relatively low dielectric loss. Meanwhile, microwave radiation makes a faster degradation than conventional heating process, indicating an indispensable non-thermal effect of microwave with copper ferrite in the process. Microwave induced holes could be responsible for the efficient degradation. The effect of annealing on crystallization and degradation process was considered here, and the intermediates and products were studied by GC-MS and LC-MS to provide a comprehensively evaluation of degradation. PMID:22704206

Chen, Hongzhe; Yang, Shaogui; Chang, Jiao; Yu, Kai; Li, Dongfang; Sun, Cheng; Li, Aimin

2012-09-01

50

Removal of triphenylmethane dyes by bacterial consortium.  

PubMed

A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50?mg/L) and malachite green (50?mg/L) dyes within 24?h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2?h. The rate of chemical oxygen demand (COD) removal increases after 24?h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes. PMID:22623907

Cheriaa, Jihane; Khaireddine, Monia; Rouabhia, Mahmoud; Bakhrouf, Amina

2012-01-01

51

Removal of Triphenylmethane Dyes by Bacterial Consortium  

PubMed Central

A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50?mg/L) and malachite green (50?mg/L) dyes within 24?h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2?h. The rate of chemical oxygen demand (COD) removal increases after 24?h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes. PMID:22623907

Cheriaa, Jihane; Khaireddine, Monia; Rouabhia, Mahmoud; Bakhrouf, Amina

2012-01-01

52

Aggregation Behavior and Chromonic Liquid Crystal Phase of a Dye Derived from Naphthalenecarboxylic Acid  

E-print Network

Aggregation Behavior and Chromonic Liquid Crystal Phase of a Dye Derived from Naphthalenecarboxylic and chromonic liquid crystal of the anionic compound Bordeaux dye, a product of the sulfonation and a columnar phase with hexagonal packing have been observed. These systems have been named chromonic liquid

Collings, Peter

53

Kinetics of the reaction of crystal violet with hydroxide ion in the critical solution of 2-butoxyethanol + water.  

PubMed

The kinetics of alkaline fading of crystal violet (CV) has been studied by UV spectrophotometry and microcalorimetry in the critical binary solution of 2-butoxyethanol + water at the initial reaction stage and various temperatures. It was found that the first-order rate constants obtained from these two methods are well accorded with each other, and the temperature dependence of the rate constant obeyed the Arrhenius equation in a temperature region far from the critical point. The critical slowing down was detected by both methods near the critical point. A simple empirical crossover model was proposed and used to analyze the experimental data to obtain the critical exponents, which were 0.158 ± 0.013 and 0.133 ± 0.012 from UV spectrophotometry and microcalorimetry, respectively, and the former was in good agreement with the theoretical prediction of 0.151. The slight lower value derived from microcalorimetry was attributed to the stirring in the microcalorimeter, which weakened the critical reduction of the diffusion coefficient. PMID:23276229

Du, Zhongyu; Mao, Shiyan; Chen, Zhiyun; Shen, Weiguo

2013-01-17

54

The molecular ordering phenomenon in dye-doped nematic liquid crystals  

NASA Astrophysics Data System (ADS)

The experimental results of this work point out the role of the guest dye molecules in the molecular ordering of nematic liquid crystals. We have discussed the changes in the energies of interactions between rod-like nematic molecules and anthraquinone dye by considering the presence of steric and dipole-dipole interactions in the dye-doped system. The concentration of the dye plays an important role in the determination of molecular ordering in such dye-doped systems. Below a certain concentration of dye (known as the critical concentration), where the interaction between the dye molecules can be neglected, the addition of dye molecules introduces some disorder into the system in the form of domain formation. Above this critical concentration, this disorder is small.

Yadav, Satya Prakash; Pandey, Kamal Kumar; Misra, Abhishek Kumar; Tripathi, Pankaj Kumar; Manohar, Rajiv

2011-03-01

55

Aggregation in Two Dye Systems That Form Chromonic Liquid Crystals  

NASA Astrophysics Data System (ADS)

X-ray scattering and various optical techniques are utilized to study the aggregation process and aggregate structure for two water-soluble dyes that form chromonic liquid crystal phases. The x-ray measurements indicate that the molecules stack in columns with a cross-section approximately equal to the area of a single molecule. The optical measurements point to an aggregation process that occurs at all concentrations, with the distribution of aggregate size shifting to larger and larger aggregates as the concentration is increased. A simple theory based on the law of mass action and an isodesmic aggregation process is in excellent agreement with the experimental data, yielding a value for the ``bond energy'' between the molecules in an aggregate.

Collings, Peter J.; Horowitz, Viva R.; Tomasik, Michelle R.

2006-03-01

56

A nano-patterned photonic crystal laser with a dye-doped liquid crystal  

NASA Astrophysics Data System (ADS)

Covering a nano-patterned titanium dioxide photonic crystal (PC) within a well-oriented film of dye-doped liquid crystal (LC), a distributed feedback laser is constructed whereby the emission characteristics can be manipulated in-situ using an electric field. This hybrid organic-inorganic structure permits simultaneous selectivity of both the beam pattern and laser wavelength by electrical addressing of the LC director. In addition, laser emission is obtained both in the plane and normal to the PC. Along with experimental data, a theoretical model is presented that is based upon an approximate calculation of the band structure of this birefringent, tuneable laser device.

Ko, Doo-Hyun; Morris, Stephen M.; Lorenz, Alexander; Castles, Flynn; Butt, Haider; Gardiner, Damian J.; Qasim, Malik M.; Wallikewitz, Bodo; Hands, Philip J. W.; Wilkinson, Timothy D.; Amaratunga, Gehan A. J.; Coles, Harry J.; Friend, Richard H.

2013-07-01

57

Self-orienting liquid crystal doped with polymer-azo-dye complex  

E-print Network

Self-orienting liquid crystal doped with polymer-azo-dye complex Elena Ouskova,* Jaana Vapaavuori stabilized liquid crystals," in ACS Symposium Series 632: Recent Advances in Liquid Crystalline Polymers, A-00076 AALTO, Finland *olena.uskova@aalto.fi Abstract: We investigate into a new type of liquid crystal

Reznikov, Yuri

58

Surface Binding and Organization of Sensitizing Dyes on Metal Oxide Single Crystal Surfaces  

SciTech Connect

Even though investigations of dye-sensitized nanocrystalline semiconductors in solar cells has dominated research on dye-sensitized semiconductors over the past two decades. Single crystal electrodes represent far simpler model systems for studying the sensitization process with a continuing train of studies dating back more than forty years. Even today single crystal surfaces prove to be more controlled experimental models for the study of dye-sensitized semiconductors than the nanocrystalline substrates. We analyzed the scientific advances in the model sensitized single crystal systems that preceded the introduction of nanocrystalline semiconductor electrodes. It then follows the single crystal research to the present, illustrating both their striking simplicity of use and clarity of interpretation relative to nanocrystalline electrodes. Researchers have employed many electrochemical, photochemical and scanning probe techniques for studying monolayer quantities of sensitizing dyes at specific crystallographic faces of different semiconductors. These methods include photochronocoulometry, electronic spectroscopy and flash photolysis of dyes at potential-controlled semiconductor electrodes and the use of total internal reflection methods. In addition, we describe the preparation of surfaces of single crystal SnS2 and TiO2 electrodes to serve as reproducible model systems for charge separation at dye sensitized solar cells. This process involves cleaving the SnS2 electrodes and a photoelectrochemical surface treatment for TiO2 that produces clean surfaces for sensitization (as verified by AFM) resulting in near unity yields for electron transfer from the molecular excited dyes into the conduction band.

Parkinson, Bruce

2010-06-04

59

Room temperature single-photon Source:Single-dye molecule fluorescence in Liquid Crystal host  

Microsoft Academic Search

We report on new approaches toward an implementation of an efficient, room temperature, deterministically polarized, single-photon source (SPS) on demand-a key hardware element for quantum information and quantum communication. Operation of a room temperature SPS is demonstrated via photon antibunching in the fluorescence from single terrylene-dye molecules embedded in a cholesteric liquid crystal host. Using oxygen-depleted liquid crystal hosts, dye-bleaching

Svetlana G. Lukishova; Ansgar W. Schmid; Andrew J. McNamara; Robert W. Boyd; Carlos R. Stroud

2003-01-01

60

Nonlinear refractive index of some anthraquinone dyes in 1294-1b liquid crystal  

NASA Astrophysics Data System (ADS)

Third order nonlinear refractive index of three anthraquinone dyes, i.e., Solvent Blue 59, Solvent Blue 35 and Solvent Green 3 doped in 1294-1b nematic liquid crystal (NLC) were studied by the single beam Z-scan technique using a continuous-wave He-Ne laser at 632.8 nm. The negative nonlinear refractive index (n 2) in the order of 10 - 5 cm 2/w for all samples was obtained. We believe that, this large nonlinearity is owing to Janossy effect and the difference in the nonlinear refractive index of our dyes can be described by the structures of dyes and the interactions between dyes and 1294-1b molecules. So as to understand the effect of dye structure on nonlinearity enhancement, the dichroic ratio of these dyes in 1294-1b was measured using polarized spectroscopy.

Milanchian, K.; Abdi, E.; Tajalli, H.; Ahmadi K., S.; Zakerhamidi, M. S.

2012-03-01

61

Trityl Dyes Patent Blue V and Brilliant Blue G - Clinical Relevance and in vitro Analysis of the Function of the Outer Blood-Retinal Barrier  

Microsoft Academic Search

The use of vital dyes during vitrectomy allows easier removal of less recognizable structures like epiretinal membranes or the internal limiting membrane (ILM). In recent years, numerous studies have investigated the use of indocyanine green (ICG), trypan blue (Membrane Blue™), triamcinolone, autologous blood and presently trityl dyes such as patent blue V (PBV, Blueron™), crystal violet and brilliant blue G

S. Mennel; C. Meyer; J. Schmidt; S. Kaempf; G. Thumann

2008-01-01

62

Characteristics of color optical shutter with dye-doped polymer network liquid crystal.  

PubMed

The optical properties and the theoretical prediction of color optical shutter with dye-doped polymer network liquid crystal (PNLC) were investigated. The view-angle dependence of reflectance according to the bias conditions showed distinctive characteristics, which could be explained from the effects of dye absorption and path length. It was also shown that the thickness dependence of reflectance was strongly influenced by the light-scattering coefficient. Our experimental results matched up well with the theoretical prediction based on the light scattering of liquid crystals in polymer network and the absorption of dichroic dye. This work indicates potential to improve the optical device using dye-doped liquid crystal-polymer composite. PMID:21368972

Lee, G H; Hwang, K Y; Jang, J E; Jin, Y W; Lee, S Y; Jung, J E

2011-03-01

63

Liquid Crystals, 2002, Vol. 29, No. 10, 13211327 Synthesis and properties of azo dye aligning layers for liquid  

E-print Network

and the formation of by-products that may contaminateangles for the liquid crystal display (LCD) [3]. Photo- the LC of azo dyes as aligning layers in active matrix liquid crystal displays. The thermal stabilityLiquid Crystals, 2002, Vol. 29, No. 10, 1321­1327 Synthesis and properties of azo dye aligning

64

27 CFR 21.111 - Gentian violet.  

Code of Federal Regulations, 2011 CFR

...violet (methyl violet, methylrosaniline chloride) occurs as a dark green powder or crystals having metallic luster. (b) Arsenic...brown, then to green, and finally to blue. (d) Insoluble matter. Not to exceed 0.25 percent when tested by the...

2011-04-01

65

27 CFR 21.111 - Gentian violet.  

Code of Federal Regulations, 2014 CFR

...violet (methyl violet, methylrosaniline chloride) occurs as a dark green powder or crystals having metallic luster. (b) Arsenic...brown, then to green, and finally to blue. (d) Insoluble matter. Not to exceed 0.25 percent when tested by the...

2014-04-01

66

27 CFR 21.111 - Gentian violet.  

Code of Federal Regulations, 2012 CFR

...violet (methyl violet, methylrosaniline chloride) occurs as a dark green powder or crystals having metallic luster. (b) Arsenic...brown, then to green, and finally to blue. (d) Insoluble matter. Not to exceed 0.25 percent when tested by the...

2012-04-01

67

27 CFR 21.111 - Gentian violet.  

Code of Federal Regulations, 2013 CFR

...violet (methyl violet, methylrosaniline chloride) occurs as a dark green powder or crystals having metallic luster. (b) Arsenic...brown, then to green, and finally to blue. (d) Insoluble matter. Not to exceed 0.25 percent when tested by the...

2013-04-01

68

Sensitized Fluorescence of Dichroic Dye in Emissive Type Liquid Crystal Displays  

Microsoft Academic Search

Sensitization effects in a fluorescent nematic liquid crystal display (LCD) have been studied using a fluorescent dichroic dye or a fluorescent liquid crystal as a sensitizer. The sensitized fluorescence intensity can be increased by ten times and a dichroic ratio of the fluorescence is also increased. Moreover, the sensitized fluorescence intensity is controlled by applying the voltage across the cell.

Rumiko Yamaguchi; Hidekazu Nagato; Hasurul Hafiz; Susumu Sato

2004-01-01

69

Light-induced rotation of dye-doped liquid crystal droplets  

NASA Astrophysics Data System (ADS)

We investigate both theoretically and experimentally the rotational dynamics of micrometric droplets of dye-doped and pure liquid crystal induced by circularly and elliptically polarized laser light. The droplets are dispersed in water and trapped in the focus of the laser beam. Since the optical torque acting on the molecular director is known to be strongly enhanced in light-absorbing dye-doped materials, the question arises whether a similar enhancement takes place also for the overall optical torque acting on the whole droplets. We searched for such enhancement by measuring and comparing the rotation speed of dye-doped droplets induced by a laser beam having a wavelength either inside or outside the dye absorption band, and also comparing it with the rotation of pure liquid crystal droplets. No enhancement was found, confirming that photoinduced dye effects are only associated with an internal exchange of angular momentum between orientational and translational degrees of freedom of matter. Our result provides also direct experimental proof of the existence of a photoinduced stress tensor in the illuminated dye-doped liquid crystal. Finally, peculiar photoinduced dynamical effects are predicted to occur in droplets in which the molecular director is not rigidly locked to the flow, but so far they could not be observed.

Manzo, C.; Paparo, D.; Marrucci, L.; Jánossy, I.

2006-05-01

70

Light-induced rotation of dye-doped liquid crystal droplets  

E-print Network

We investigate both theoretically and experimentally the rotational dynamics of micrometric droplets of dye-doped and pure liquid crystal induced by circularly and elliptically polarized laser light. The droplets are dispersed in water and trapped in the focus of the laser beam. Since the optical torque acting on the molecular director is known to be strongly enhanced in light-absorbing dye-doped materials, the question arises whether a similar enhancement takes place also for the overall optical torque acting on the whole droplets. We searched for such enhancement by measuring and comparing the rotation speed of dye-doped droplets induced by a laser beam having a wavelength either inside or outside the dye absorption band, and also comparing it with the rotation of pure liquid crystal droplets. No enhancement was found, confirming that photoinduced dye effects are only associated with an internal exchange of angular momentum between orientational and translational degrees of freedom of matter. Our result provides also the first direct experimental proof of the existence of a photoinduced stress tensor in the illuminated dye-doped liquid crystal. Finally, peculiar photoinduced dynamical effects are predicted to occur in droplets in which the molecular director is not rigidly locked to the flow, but so far they could not be observed.

C. Manzo; D. Paparo; L. Marrucci; I. Janossy

2007-12-05

71

Spatially tunable laser emission in dye-doped photonic liquid crystals Yuhua Huang, Ying Zhou, and Shin-Tson Wua  

E-print Network

Spatially tunable laser emission in dye-doped photonic liquid crystals Yuhua Huang, Ying Zhou laser emission of the dye-doped cholesteric liquid crystal CLC cell using a one-dimensional temperature wavelength by external factors including electric, magnetic, acoustic fields, temperature, and light

Wu, Shin-Tson

72

Derivatives of oxazine 17 as laser dyes for liquid-crystal matrices  

SciTech Connect

It is proposed to activate liquid-crystal matrices with 3-acyloxy derivatives of oxazine 17 which are highly soluble in such matrices and exhibit a high degree of order. The results are reported of an investigation of lasing of these dyes in isotropic and mesomorphic phases.

Alekseev, N.N.; Gorelenko, A.Y.; Grozhik, V.A.; Kalosha, I.I.; Kovalev, A.A.; Loiko, L.S.; Tolkachev, V.A.

1985-10-01

73

Enhancement of the fluorescence of triphenylmethane dyes caused by their interaction with nanoparticles from ?-diketonate complexes  

NASA Astrophysics Data System (ADS)

We have studied the absorption and fluorescence spectra of Malachite Green and Crystal Violet in aqueous and alcoholic-aqueous solutions in which nanoparticles from Ln(III) and Sc(III) diketonates are formed at concentrations of complexes in a solution of 5-30 ?M. We have shown that, if the concentrations of the dyes in the solution are lower than 0.5 ?M, dye molecules are incorporated completely into nanoparticles or are precipitated onto their surface. The fluorescence intensity of these incorporated and adsorbed Malachite Green and Crystal Violet molecules increases by several orders of magnitude compared to the solution, which takes place because of a sharp increase in the fluorescence quantum yields of these dyes and at the expense of the sensitization of their fluorescence upon energy transfer from ?-diketonate complexes entering into the composition of nanoparticles. We have shown that, if there is no concentration quenching, the values of the fluorescence quantum yield of the Crystal Violet dye incorporated into nanoparticles and adsorbed on their surface vary from 0.06 to 0.13, i.e., are close to the fluorescence quantum yield of this dye in solid solutions of sucrose acetate at room temperature. The independence of the fluorescence quantum yield of Crystal Violet on the morphology of nanoparticles testifies to a high binding constant of complexes and the dye. The considerable fluorescence quantum yields of triphenylmethane dyes in nanoparticles and sensitization of their fluorescence by nanoparticle-forming complexes make it possible to determine the concentration of these dyes in aqueous solutions by the luminescent method in the range of up to 1 nM.

Sveshnikova, E. B.; Ermolaev, V. L.

2014-08-01

74

Dye-concentration-dependent lasing behaviors and spectral characteristics of cholesteric liquid crystals  

NASA Astrophysics Data System (ADS)

The laser behavior and spectral changes occurring in cholesteric liquid crystals with varying dye-doped concentrations were investigated when pumped at 532 nm. It was found that the long-wavelength band edge and the laser line exhibit a blue shift over 21 nm with increasing dye concentration. The circularly polarized fluorescence spectra were examined, and the location of the sense reversion of circular polarization was determined to coincide well with the discrete lasing lines. The blue shift can be ascribed to the decrease in average refractive index and pitch of the dye-doped cholesteric liquid crystals. The dependence of the slope efficiency and threshold energy on the dye concentration can be attributed to the shift in photonic stopband and the change in penetration depth of excitation. The temperature and incident angle of pumping beam also have a significant impact on the lasing properties. The optimal dye concentration is found to be 0.5 wt% at 30.5 °C with an incident angle of 10°. The laser emission located at 601.4 nm with slope efficiency of 4 % was achieved above the threshold energy of 14.3 ?J.

Wang, Zhongyang; Yang, Can; Li, Wensong; Chen, Lujian; Wang, Xiaozhong; Cai, Zhiping

2014-06-01

75

Dye-Induced Enhancement of Optical Nonlinearity in Liquids and Liquid Crystals  

SciTech Connect

Optical nonlinearity of liquid crystals (LC) in the isotropic phase can be enhanced by 1 order of magnitude by dissolving 0.1{percent} of anthraquinone dye in the LC. The enhancement decreases by {approximately}30{percent} when the LC transforms into the nematic phase. The same guest-host effect also exists in non-LC liquids. It can be explained by a model based on the change of guest-host interaction induced by optical excitations of the dye. {copyright} {ital 1996} {ital The American Physical Society}

Muenster, R.; Jarasch, M.; Zhuang, X.; Shen, Y. [Department of Physics, University of California, Berkeley, California 94720-7300 (United States)] [Department of Physics, University of California, Berkeley, California 94720-7300 (United States)

1997-01-01

76

Enhancement of crystallization with nucleotide ligands identified by dye-ligand affinity chromatography.  

PubMed

Ligands interacting with Mycobacterium tuberculosis recombinant proteins were identified through use of the ability of Cibacron Blue F3GA dye to interact with nucleoside/nucleotide binding proteins, and the effects of these ligands on crystallization were examined. Co-crystallization with ligands enhanced crystallization and enabled X-ray diffraction data to be collected to a resolution of atleast 2.7 Å for 5 of 10 proteins tested. Additionally, clues about individual proteins’ functions were obtained from their interactions with each of a panel of ligands. PMID:22286688

Kim, Heungbok; Webster, Cecelia; Roberts, Justin K M; Kositsawat, Juthamas; Hung, Li-Wei; Terwilliger, Thomas C; Kim, Chang-Yub

2012-06-01

77

Molecular Assembly and Liquid Crystal Properties of a Near-IR Absorbing Dye  

NASA Astrophysics Data System (ADS)

The molecules of the near-IR absorbing dye IR-806 spontaneously assemble in water at very low concentrations, forming a liquid crystal phase at room temperature when the concentration is above 0.6 wt%. Unlike most chromonic liquid crystal systems, macroscopic phase separation between the isotropic and liquid crystal phases is not observed. Also unlike most chromonic liquid crystal systems, the absorption spectrum of IR-806 changes dramatically as the concentration increases and molecular assembly proceeds. Analysis of the absorption spectra provides evidence of an isodesmic assembly process at an extremely low concentration, followed by a second non-isodesmic assembly process at a higher concentration just before the liquid crystal phase appears.

Collings, Peter; Mills, Elizabeth

2012-02-01

78

Transition Metal Dithiolene Near-IR Dyes and Their Applications in Liquid Crystal Devices  

Microsoft Academic Search

Numerous commercial and military applications exist for guest–host liquid crystal (LC) devices operating in the near- to mid-IR region. Progress in this area has been hindered by the severe lack of near-IR dyes with good solubility in the LC host, low impact on the inherent order of the LC phase, good thermal and chemical stability, and a large absorbance maximum

K. L. Marshall; K. Lotito; A. G. Noto; P. Chang

2006-01-01

79

Transition metal dithiolene complexes as near-IR dyes for liquid crystal device applications  

Microsoft Academic Search

Both commercial and military applications (e.g., free-space IR communications and sensor protection) exist for guest-host liquid crystal (LC) devices operating in the near- to mid-IR region. Progress in this area has been hindered by the severe lack of near-IR dyes with good solubility in the LC host, low impact on the inherent order of the LC phase, good thermal and

Kenneth L. Marshall; Benjamin Schudel; Irene A. Lippa

2003-01-01

80

Transition metal dithiolene complexes as near-IR dyes for liquid crystal device applications  

Microsoft Academic Search

Both commercial and military applications (e.g., free-space IR communications and sensor protection) exist for guest-host liquid crystal (LC) devices operating in the near- to mid-IR region. Progress in this area has been hindered by the severe lack of near-IR dyes with good solubility in the LC host, low impact on the inherent order of the LC phase, good thermal and

Kenneth L. Marshall; Benjamin Schudel; Irene A. Lippa

2004-01-01

81

Nonlinear optical organic co-crystals of merocyanine dyes and phenolic derivatives with short hydrogen bonds  

NASA Astrophysics Data System (ADS)

We investigated the co-crystallization of merocyanine dyes M ( M: R-N +C 5H 4-CH?CH-C 6H 4O -, M1: R=CH 3, M2: R=HO-CH 2-CH 2-) with phenolic and aniline derivatives and show that the short or very short hydrogen bond between the two phenolic oxygen atoms which lead to a self-assembly of the M dyes and phenol derivatives is the key steering force for the co-crystallization process. The co-crystal formation was studied by melting point determination, by second-harmonic generation using the Kurtz and Perry powder test, and X-ray structural analysis. We present detailed results on the growth, polymorphism, and nonlinear optical properties of co-crystals of derivatives of M1 ( M2) and m-nitrophenol (mNP) and co-crystals of M2 and methyl 2,4-dihydroxybenzoate (MDB). Three phases of the co-crystal M2·mNP and three phases of the co-crystal M2·MDB were found. Both M2·MDB(I) and (II) have the same crystal structure (space group symmetry Cc determined by X-ray diffraction), but show different linear and nonlinear optical properties. This unusual property in the co-crystals of M2·MDB(I) and (II) may be caused by a different proton location of the short hydrogen bond (O-H-O) in the aggregation between M2 and MDB which could not be resolved by X-ray diffraction.

Bosshard, Christian; Pan, Feng; Wong, Man Shing; Manetta, Sabine; Spreiter, Rolf; Cai, Chengzhi; Günter, Peter; Gramlich, Volker

1999-07-01

82

Influence of dye molecules on the birefringence of liquid crystal mixtures at near infrared frequencies.  

PubMed

The optical properties of nematic liquid crystals have been extensively exploited in the production of devices working in the visible range of the spectrum. These same properties can be employed to make devices that function in the near infrared as required for telecommunications applications. However, it is generally observed that the birefringence of liquid crystal mixtures decreases with increasing wavelength, making it important to identify new materials, optimized for use in the near infrared region. One route to high birefringence is to operate close to an absorption band edge, which in the present context implies choosing highly conjugated materials which are potentially colored and, thus, not suited to traditional display applications. In this paper we explore the usefulness of dye molecules as birefringence enhancers in mixtures with conventional nematic liquid crystals. The optical properties, in particular, the absorption edge, polarizability, and birefringence, of families of known dyes are calculated at optical (589 nm) and infrared (1550 nm) wavelengths, using electronic density functional theory. We demonstrate the expected correlation between the proximity of the absorption edge and the magnitude of the birefringence, and estimate the birefringence enhancement occurring when each dye is incorporated in a guest-host system. PMID:17867774

Simpson, S H; Richardson, R M; Hanna, S

2007-09-14

83

Aggregation behavior and chromonic liquid crystal properties of an anionic monoazo dye  

NASA Astrophysics Data System (ADS)

X-ray scattering and various optical techniques are utilized to study the aggregation process and chromonic liquid crystal phase of the anionic monoazo dye Sunset Yellow FCF. The x-ray results demonstrate that aggregation involves ?-? stacking of the molecules into columns, with the columns undergoing a phase transition to an orientationally ordered chromonic liquid crystal phase at high dye concentration. Optical absorption measurements on dilute solutions reveal that the aggregation takes place at all concentrations, with the average aggregation number increasing with concentration. A simple theory based on the law of mass action and an isodesmic aggregation process is in excellent agreement with the experimental data and yields a value for the “bond” energy between molecules in an aggregate. Measurements of the birefringence and order parameter are also performed as a function of temperature in the chromonic liquid crystal phase. The agreement between these results and a more complicated theory of aggregation is quite reasonable. Overall, these results both confirm that the aggregation process for some dyes is isodesmic and provide a second example of a well-characterized chromonic system.

Horowitz, Viva R.; Janowitz, Lauren A.; Modic, Aaron L.; Heiney, Paul A.; Collings, Peter J.

2005-10-01

84

Aggregation behavior and chromonic liquid crystal properties of an anionic monoazo dye.  

PubMed

X-ray scattering and various optical techniques are utilized to study the aggregation process and chromonic liquid crystal phase of the anionic monoazo dye Sunset Yellow FCF. The x-ray results demonstrate that aggregation involves pi-pi stacking of the molecules into columns, with the columns undergoing a phase transition to an orientationally ordered chromonic liquid crystal phase at high dye concentration. Optical absorption measurements on dilute solutions reveal that the aggregation takes place at all concentrations, with the average aggregation number increasing with concentration. A simple theory based on the law of mass action and an isodesmic aggregation process is in excellent agreement with the experimental data and yields a value for the "bond" energy between molecules in an aggregate. Measurements of the birefringence and order parameter are also performed as a function of temperature in the chromonic liquid crystal phase. The agreement between these results and a more complicated theory of aggregation is quite reasonable. Overall, these results both confirm that the aggregation process for some dyes is isodesmic and provide a second example of a well-characterized chromonic system. PMID:16383405

Horowitz, Viva R; Janowitz, Lauren A; Modic, Aaron L; Heiney, Paul A; Collings, Peter J

2005-10-01

85

Aggregation behavior and chromonic liquid crystal properties of an anionic monoazo dye  

SciTech Connect

X-ray scattering and various optical techniques are utilized to study the aggregation process and chromonic liquid crystal phase of the anionic monoazo dye Sunset Yellow FCF. The x-ray results demonstrate that aggregation involves {pi}-{pi} stacking of the molecules into columns, with the columns undergoing a phase transition to an orientationally ordered chromonic liquid crystal phase at high dye concentration. Optical absorption measurements on dilute solutions reveal that the aggregation takes place at all concentrations, with the average aggregation number increasing with concentration. A simple theory based on the law of mass action and an isodesmic aggregation process is in excellent agreement with the experimental data and yields a value for the 'bond' energy between molecules in an aggregate. Measurements of the birefringence and order parameter are also performed as a function of temperature in the chromonic liquid crystal phase. The agreement between these results and a more complicated theory of aggregation is quite reasonable. Overall, these results both confirm that the aggregation process for some dyes is isodesmic and provide a second example of a well-characterized chromonic system.

Horowitz, Viva R.; Janowitz, Lauren A.; Modic, Aaron L. [Department of Physics and Astronomy, Swarthmore College, Swarthmore, Pennsylvania 19081 (United States); Heiney, Paul A. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Collings, Peter J. [Department of Physics and Astronomy, Swarthmore College, Swarthmore, Pennsylvania 19081 (United States); Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

2005-10-01

86

Immobilization of Laccase in Alginate-Gelatin Mixed Gel and Decolorization of Synthetic Dyes  

PubMed Central

Alginate-gelatin mixed gel was applied to immobilized laccase for decolorization of some synthetic dyes including crystal violet. The immobilization procedure was accomplished by adding alginate to a gelatin solution containing the enzyme and the subsequent dropwise addition of the mixture into a stirred CaCl2 solution. The obtained data showed that both immobilized and free enzymes acted optimally at 50°C for removal of crystal violet, but the entrapped enzyme showed higher thermal stability compared to the free enzyme. The immobilized enzyme represented optimum decolorization at pH 8. Reusability of the entrapped laccase was also studied and the results showed that ca. 85% activity was retained after five successive cycles. The best removal condition was applied for decolorization of seven other synthetic dyes. Results showed that the maximum and minimum dye removal was related to amido black 10B and eosin, respectively. PMID:22899898

Mogharabi, Mehdi; Nassiri-Koopaei, Nasser; Bozorgi-Koushalshahi, Maryam; Nafissi-Varcheh, Nastaran; Bagherzadeh, Ghodsieh; Faramarzi, Mohammad Ali

2012-01-01

87

Emission property of inverse opal photonic crystal TiO2 infiltrated by laser dye  

NASA Astrophysics Data System (ADS)

Photonic crystal has received much attention due to their unique structure and optical property. Photonic crystal which has photonic bandgap can be used to manipulate propagation of light and can be apply in designing integrated optical devices to realize all-optical circuits. Three dimensional photonic crystals which have complete photonic bandgap give more potential in application since they can manipulate propagation of light in all direction. Modified opal photonic crystal by infiltrating matrix material into voids between particles produce inverse opal photonic crystal which has complete photonic bandgap. In this experiment, opal photonic crystal formed from particles polystyrene was used as template material to produce inverse opal photonic crystal. Material dielectric TiO2 which has refractive index about 2,5-2,8 was used as matrix material to fill voids between particles. Simple method that was used to infiltrate precursor TiO2 dielectric is dipping method. Calcination as the final process was done at 550°C to remove all template material to form an air hole structure called inverse opal photonic crystal. To investigate inverse opal photonic crystal TiO2as an optical devices, DCMlaser dye wasinfiltrated into inverse opal TiO2. Based on emission measurement, there is a sharp peak at 808 nm that is identified as amplified spontaneous emission (ASE).

Safriani, Lusi; Wahid, Abdul; Hidayat, Sahrul

2013-09-01

88

Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal Denis Fedorenko,1,* Kostyantyn Slyusarenko,1  

E-print Network

of the easy axis of dye-doped nematic liquid crystal on an aligning polymer surface. The observed driftLight-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal Denis. INTRODUCTION The traditional description of reorientation of the liquid crystal LC director in an electric

Reznikov, Yuri

89

Analytical and preparative chromatographic procedures for obtaining pure cresyl violet and cresyl red from commercial cresyl violet.  

PubMed

Cresyl violet and cresyl red, components of commercial cresyl violet acetate, were separated and purified using preparative column liquid chromatography. The stationary phase was silica gel and gradient elution was carried out using chloroform:methanol. The purified dyes were obtained in high yield; 51% of the original lot was recovered as cresyl violet and 40% as cresyl red. Separated materials were characterized by nuclear magnetic resonance and mass spectroscopy; UV-visible and Fourier-transform infrared spectra also were obtained for samples of pure cresyl violet and cresyl red. The colored constituents of the commercial dye lot were identified using thin layer chromatography and reverse phase high performance liquid chromatography. Both methodologies were suitable for routine testing; reverse phase high performance liquid chromatography is an appropriate tool for quality control and high resolution identification of these compounds. PMID:25358291

Urrutia, M N; Ortiz, C S

2015-04-01

90

Electrically and all-optically controllable random lasers based on dye-doped liquid crystal films  

NASA Astrophysics Data System (ADS)

This study elucidates electrically and all-optically controllable random lasers in dye-doped liquid crystals with adding a photoisomerizable dye. The lasing intensities and the energy thresholds of the random lasers can be electrically controlled below the Fréedericksz transition threshold or all-optically controlled sequentially with a two-step exposure of UV and green beams. The below-threshold-electric- and all-optical controllabilities of the random lasers are attributable to the effective change of the spatial fluctuation of the orientational order and thus of the dielectric tensor of LCs by changing the electric-field-aligned order of LCs below the threshold and via the isothermal nematic-isotropic phase transition of LCs, respectively; thereby changing the diffusion constant and thus the scattering strength of the fluorescence photons in their recurrent multiple scattering. This can result in the change in the lasing intensity and thus the energy threshold of the random lasers.

Lee, Chia-Rong; Lin, Jia-De; Huang, Bo-Yuang

2012-03-01

91

Transition Metal Dithiolene Complexes as Near-IR Dyes for Liquid Crystal Device Applications  

SciTech Connect

(B204)Both commercial and military applications (e.g., free-space IR communications and sensor protection) exist for guest-host liquid crystal (LC) devices operating in the near- to mid-IR region. Progress in this area has been hindered by the severe lack of near-IR dyes with good solubility in the LC host, low impact on the inherent order of the LC phase, good thermal and chemical stability, and a large absorbance maximum tunable by structural modification over a broad range of the near-IR region. Transition metal complexes based on nickel, palladium, or platinum dithiolene cores show substantial promise in meeting these requirements. These new dye complexes are extraordinarily stable, possess liquid crystalline phases in their own right with the proper terminal functional groups, and can have melting points below room temperature. The latter property is especially significant for producing liquid crystal/dye mixtures with both high dye concentration and good resistance to phase separation. Because they are zerovalent, they can exhibit high solubility in LC hosts (up to 10 wt%). The lmax in these materials can range from 600 nm to 1600 nm, depending on structure. With enantiomerically enriched terminal substituents, nickel dithiolenes can induce a chiral mesophase in a nonchiral nematic host. This finding opens the possibility of generating novel LC mixtures with two degrees of tunability: an electronic absorbance band tunable by synthesis, and a selective reflection band tunable by temperature or applied electric field. Such a materials system would be particularly advantageous in sensor protection for dealing with frequency-agile laser threats.

Marshall, K.L.; Schudel, B.; Lippa, I.A.

2003-12-31

92

Tunable WGM resonators from optically trapped dye doped liquid crystal emulsion droplets  

NASA Astrophysics Data System (ADS)

We have built a complex apparatus for optical trapping, stretching, heating and concurrent whispering gallery mode (WGM) lasing excitation of liquid crystal (LC) emulsion micro-droplets doped with various fluorescent dyes. We have explored the changes of WGM lasing wavelength when the LC droplets were optically stretched or electrically heated beyond the transition to the isotropic phase. We have found that the range of lasing wavelengths was in some cases considerably higher than when we optically stretched ordinary fluorescent oil droplets in our previous experiments.

Šerý, Mojmír.; Pilát, Zden?k.; Ježek, Jan; Aas, Mehdi; Kiraz, Alper; Zemánek, Pavel

2014-09-01

93

Low threshold and coherent random lasing from dye-doped cholesteric liquid crystals using oriented cells  

NASA Astrophysics Data System (ADS)

We demonstrate the realization of a coherent random laser in a strongly scattering medium, which contained a dispersive solution of Ag nanoparticles and laser dye 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) in cholesteric liquid crystals that was injected into an oriented cell. Multiple scattering of Ag nanoparticles and helical domains greatly enhanced by the oriented cell confinement effect was experimentally verified to account for the coherent lasing observed in our oriented system. Based on non-oriented cells and oriented cells, this paper extends the active and scattering media-based random lasers from the incoherent regime to the coherent regime.

Li, Longwu; Deng, Luogen

2013-08-01

94

All-optical switchable holographic Fresnel lens based on azo-dye-doped polymer-dispersed liquid crystals.  

PubMed

Fabrication of an all-optical switchable holographic liquid crystal (LC) Fresnel lens based on azo-dye-doped polymer-dispersed LCs is reported using a Michelson interferometer. It is found that, upon circularly polarized photoirradiation, the diffraction efficiency of the fabricated Fresnel lens was increased significantly in a reversible manner. We believe this is due to the anisotropy induced by reorientation of the LC molecules coupled with azo-dye molecule orientation due to trans-cis-trans photoisomerization, which modulates the refractive index of the LC-rich regions. We also studied the effect of azo dye on the polarization dependency of the fabricated lens. PMID:21833102

Jashnsaz, Hossein; Nataj, Nahid Hosain; Mohajerani, Ezeddin; Khabbazi, Amir

2011-08-01

95

Aggregation Properties and Liquid Crystal Phase of a Dye Based on Naphthalenetetracarboxylic Acid  

NASA Astrophysics Data System (ADS)

R003 is a dye produced for thin film optical components by Optiva, Inc.^1 made from the sulfonation of the dibenzimidazole derivative of naphthalenetetracarboxylic acid. Its molecular structure is very different from the aggregating food dye previously investigated in our laboratory^2 and R003 forms a liquid crystal phase at significantly lower concentrations. We have performed polarizing microscopy, absorption spectroscopy, and x-ray diffraction experiments in order to determine the phase diagram and aggregate structure. In addition, we have included both translational and orientational entropy in the theoretical analysis of the aggregation process, and have used a more realistic lineshape in analyzing the absorption data. Our results indicate that the ``bond energy'' for molecules in an aggregate is even larger than for the previously studied dye and that the aggregate structure has a cross-sectional area equal to two or three molecular areas rather than one.^1Lazarev, P., N. Ovchinnikova, M. Paukshto, SID Int. Symp. Digest of Tech. Papers, San Jose, California, June XXXII, 571 (2001).^2V. R. Horowitz, L. A. Janowitz, A. L. Modic, P. A. Heiney, and P. J. Collings, Phys. Rev. E 72, 041710 (2005).

Tomasik, Michelle; Collings, Peter

2007-03-01

96

Single-mode lasing from dye-doped holographic polymer-dispersed liquid crystal transmission gratings  

NASA Astrophysics Data System (ADS)

We demonstrate single-mode laser operation in dye-doped holographic polymer-dispersed liquid crystal (HPDLC) transmission gratings. The gratings are fabricated in cells made from specifically chosen glass substrates to decrease the refractive index difference between the waveguide core layer and cladding layer. The phase separation degree of liquid crystal after holographic recording is further optimized to confine only the lowest propagation mode in the device. The mode selection mechanism is explained under the framework of the waveguide distributed feedback (DFB) theory. The wavelength of single-mode lasing can be tuned between 620 and 660 nm by varying the grating period. Our results show the HPDLC technique could provide single-mode organic DFB lasers in a tunable, simple, and large-area manner.

Huang, Wenbin; Liu, Quan; Xuan, Li; Chen, Linsen

2014-12-01

97

Biphotonic-induced reorientation inversion in azo-dye-doped liquid crystal films.  

PubMed

The reorientation inversion of liquid crystal molecules in azo-dye-doped liquid crystal (ADDLC) films irradiated by biphotonic (green and red light) lasers is studied using the self-phase-modulation method. The results show that the induced change of refractive index (?n) in an ADDLC cell illuminated with a fixed intensity of green light increases with the red-light intensity. Notably, the value of ?n is initially negative, and becomes positive when the intensity of the red laser is increasing. It is due to the fact that an extra positive torque is exerted on the LCs, which is produced by cis-isomers upon absorbing red light to compensate the negative torque induced by the excitation of the green light. PMID:21747464

Lin, Hui-Chi; Chu, Chia-Wei; Li, Ming-Shian; Fuh, Andy Ying-Guey

2011-07-01

98

Security devices based on liquid crystals doped with a colour dye  

NASA Astrophysics Data System (ADS)

Liquid crystal properties make them useful for the development of security devices in applications of authentication and detection of fakes. Induced orientation of liquid crystal molecules and birefringence are the two main properties used in security devices. Employing liquid crystal and dichroic colorants, we have developed devices that show, with the aid of a polarizer, multiple images on each side of the device. Rubbed polyimide is used as alignment layer on each substrate of the LC cell. By rubbing the polyimide in different directions in each substrate it is possible to create any kind of symbols, drawings or motifs with a greyscale; the more complex the created device is, the more difficult is to fake it. To identify the motifs it is necessary to use polarized light. Depending on whether the polarizer is located in front of the LC cell or behind it, different motifs from one or the other substrate are shown. The effect arises from the dopant colour dye added to the liquid crystal, the induced orientation and the twist structure. In practice, a grazing reflection on a dielectric surface is polarized enough to see the effect. Any LC flat panel display can obviously be used as backlight as well.

Carrasco-Vela, C.; Quintana, X.; Otón, E.; Geday, M. A.; Otón, J. M.

2011-12-01

99

Concentration and pump intensity dependent gain studies for disodium flourescein (FDS), cresyl violet (CV), and rhodamine- 590 (Cl) and cresyl violet mixture  

NASA Astrophysics Data System (ADS)

The dye concentration dependence gain spectra for disodium fluorescein (FDS) cresyl violet (CV) and a dye mixture [Rh 590 (Cl)+CV] dissolved in methanol have been studied by amplified spontaneous emission (ASE) technique under pulsed N 2-laser excitation. On comparing the efficiency curves, the dominant role of photoquenching (excited state absorption) was clearly observed in the non-rigid dye FDS, whereas it is non-existent in rigid dye CV at the same concentration. In case of a dye mixture, the energy transfer excitation was found to overcome the inner filter effect and other losses. The various energy transfer mechanisms in these dyes have also been discussed.

Gaur, Arun; Taneja, L.; Sharma, A. K.; Mohan, D.; Singh, R. D.

1991-06-01

100

Picosecond rotational reorientation of cresyl violet in polymer solution  

NASA Astrophysics Data System (ADS)

Picosecond absorption spectroscopy has been used to study the rotational reorientation of cresyi violet in methanol solutions containing poly(ethylene oxide). The increase in the rotational reorientation time with increasing polymer concentration can be attributed to the short-range hydrodynamic interactions between the dye and entangled polymer chains.

Quitevis, E. L.; Casey, K. G.; Sinor, T. W.

1986-11-01

101

SORPTION AND TOXICITY OF AZO AND TRIPHENYLMETHANE DYES TO AQUATIC MICROBIAL POPULATIONS  

EPA Science Inventory

Toxicity and sorption of five azo and triphenylmethane dyes to freshwater microbiota were determined to assessment, in part, the risks that these dyes may pose to the aquatic environment. The toxicities of Basic Violet 1, Basic Violet 2, Basic Violet 3, Basic Green 4 and Tropaeol...

102

Light-induced rotation of dye-doped liquid crystal droplets C. Manzo, D. Paparo, and L. Marrucci*  

E-print Network

crystal induced by circularly and elliptically polarized laser light. The droplets are dispersed in water to be strongly enhanced in light-absorbing dye-doped materials, the question arises whether a similar enhancement of freedom of matter. Our result provides also direct experimental proof of the existence of a photo- induced

Marrucci, Lorenzo

103

Violet root rot  

Technology Transfer Automated Retrieval System (TEKTRAN)

The fungus causing violet root rot, Helicobasidium brebissonii (anamorph Rhizoctonia crocorum), is widely distributed in Europe and North America but is rarely of much economic importance on alfalfa. The disease has also been reported in Australia, Argentina, and Iran. The disease is characterized b...

104

Compositional changes in red and violet smoke mixes after combustion  

SciTech Connect

Anthraquinone-derived dyes are commonly used in colored dye mixes prepared for signal smoke grenades. Biological studies have shown, however, that a number of these dyes exhibit bacterial mutagenicity. In addition, these dyes are similar in structure to several polycyclic aromatic hydrocarbons which are well-known carcinogens. The grenades contain not only anthraquinone-derived dyes, but also a pyrotechnic fuel and cooling and starting mixes consisting primarily of potassium chlorate and nitrate, sodium bicarbonate, and sulfur. These dyes are volatilized at temperatures up to 550/sup 0/C during the detonation of the grenade, which could subject the dyes to oxidative and pyrolytic reactions that could result in a variety of reaction by-products. As part of a program to investigate possible environmental and occupational risks of the colored smoke dyes and in signal grenades, two colored smoke mixes, red and violet, have been studied both before and after detonation to evaluate any differences in composition due to the combustion process. This report focuses primarily on the separation and identification of the components of the original and combusted red and violet smoke mixes. The conditions for the detonation of the smoke grenades and sampling of the combusted smoke mixes are also discussed.

Buchanan, M.V.; Rubin, I.B.; Moneyhun, J.H.

1983-01-01

105

Highly Efficient Plastic Crystal Ionic Conductors for Solid-state Dye-sensitized Solar Cells  

PubMed Central

We have developed highly efficient, ambient temperature, solid-state ionic conductors (SSICs) for dye-sensitized solar cells (DSSCs) by doping a molecular plastic crystal, succinonitrile (SN), with trialkyl-substituted imidazolium iodide salts. High performance SSICs with enhanced ionic conductivity (2–4?mScm?1) were obtained. High performance solid-state DSSCs with power conversion efficiency of 7.8% were fabricated using our SSICs combined with unique hierarchically nanostructured TiO2 sphere (TiO2-SP) photoelectrodes; these electrodes have significant macroporosity, which assists penetration of the solid electrolyte into the electrode. The performance of our solid-state DSSCs is, to the best of our knowledge, the highest reported thus far for cells using plastic crystal-based SSICs, and is comparable to that of the state-of-the-art DSSCs which use ionic liquid type electrolytes. This report provides a logical strategy for the development of efficient plastic crystal-based SSICs for DSSCs and other electrochemical devices. PMID:24343425

Hwang, Daesub; Kim, Dong Young; Jo, Seong Mu; Armel, Vanessa; MacFarlane, Douglas R.; Kim, Dongho; Jang, Sung-Yeon

2013-01-01

106

Aggregation behavior and chromonic liquid crystal phase of a dye derived from naphthalenecarboxylic acid.  

PubMed

Polarizing microscopy, X-ray scattering, and absorption spectroscopy are used to investigate the aggregation process and chromonic liquid crystal of the anionic compound Bordeaux dye, a product of the sulfonation of the dibenzimidazole derivative of naphthalenetetracarboxylic acid. Polarizing microscopy reveals that the liquid crystal phase forms at room temperature when the concentration is only about 6 wt%, a value lower than what is found in many aggregating systems. The X-ray results indicate that the aggregation is via columns, with a cross-sectional area about 2.5 times larger than the individual molecule. Absorption spectroscopy shows a significant change in the absorption spectrum due to aggregation, which is nicely explained by a simple theory of isodesmic aggregation and excitonic coupling between the molecules in an aggregate. The "stacking free energy change" for a molecule in an aggregate relative to a molecule in solution is estimated to be about 9 kBT, a larger value than that found in the one other system where it has been estimated. PMID:18646804

Tomasik, Michelle R; Collings, Peter J

2008-08-14

107

Synchronously pumped double mode-locking of a rhodamine 6G-Cresyl violet mixture  

NASA Astrophysics Data System (ADS)

Rhodamine 6G-Cresyl violet dye mixtures are synchronously pumped to obtain double mode-locking. Subpicosecond pulses are obtained at two wavelengths in an experimental setup that is easy to implement into existing conventional synchronously pumped systems. In addition, the excitation mechanisms of the secondary dye are discussed and evidence for resonant energy transfer is presented.

Selfridge, R.; Dienes, A.

1985-05-01

108

Optical tuning of extraordinary optical transmission through a metallic hole array using azobenzene dye-doped nematic liquid crystal  

NASA Astrophysics Data System (ADS)

Optical tuning of extraordinary optical transmission (EOT) through a metallic hole array is achieved using an azobenzene dye-doped nematic liquid crystal. The liquid crystal is aligned homeotropically on the hole array and is sandwiched by a counter substrate placed at a distance of approximately 1 µm from the hole array. Upon UV irradiation, the azobenzene dye photo-isomerizes from the trans conformation to the cis conformation and disturbs the liquid crystalline order, causing a decrease in the effective refractive index. The tuning range achieved was 80 nm, and corresponded to a refractive index shift of 0.086. Optical tuning of EOT properties is potentially important for future all-optical processing of signals.

Kobashi, Junji; Yoshida, Hiroyuki; Matsui, Takayuki; Miura, Atsushi; Ikeda, Naoki; Sugimoto, Yoshimasa; Fujikawa, Hisayoshi; Ozaki, Masanori

2014-01-01

109

Self-alignment of dye molecules in micelles and lamellae for three-dimensional imaging of lyotropic liquid crystals.  

PubMed

We report alignment of anisotropic amphiphilic dye molecules within oblate and prolate anisotropic micelles and lamellae, the basic building blocks of surfactant-based lyotropic liquid crystals. Absorption and fluorescence transition dipole moments of these dye molecules orient either parallel or orthogonal to the liquid crystal director. This alignment enables three-dimensional visualization of director structures and defects in different lyotropic mesophases by means of fluorescence confocal polarizing microscopy and two-photon excitation fluorescence polarizing microscopy. The studied structures include nematic tactoids, Schlieren texture with disclinations in the calamitic nematic phase, oily streaks in the lamellar phase, developable domains in the columnar hexagonal phase, and various types of line defects in the discotic cholesteric phase. Orientational three-dimensional imaging of structures in the lyotropic cholesterics reveals large Burgers vector dislocations in cholesteric layering with singular disclinations in the dislocation cores that are not common for their thermotropic counterparts. PMID:21598933

Liu, Qingkun; Beier, Corinne; Evans, Julian; Lee, Taewoo; He, Sailing; Smalyukh, Ivan I

2011-06-21

110

Rutile TiO 2 microspheres with exposed nano-acicular single crystals for dye-sensitized solar cells  

Microsoft Academic Search

Uniquely structured rutile TiO2 microspheres with exposed nano-acicular single crystals have been successfully synthesized via a facile hydrothermal method.\\u000a After calcination at 450 °C for 2 h, the rutile TiO2 microspheres with a high surface area of 132 m2\\/g have been utilized as a light harvesting enhancement material for dye-sensitized solar cells (DSSCs). The resultant DSSCs\\u000a exhibit an overall light

Haimin Zhang; Hua Yu; Yanhe Han; Porun Liu; Shanqing Zhang; Peng Wang; Yibing Cheng; Huijun Zhao

111

Laser kinetic processes in dye mixtures  

SciTech Connect

Radiation from rhodamine 6G+cresyl violet and rhodamine B+cresyl violet dye mixtures in ethyl alcohol pumped by N/sub 2/ laser light were studied. The rate constants of resonant transfer in the mixtures were determined. The radiative transfer processes are discussed.

Lei Jie; Fu Honglang

1988-11-01

112

Novel pyridinium inner salt dye and its complexes: synthesis, crystal structures and photophysical properties.  

PubMed

Two novel metal complexes, namely [Tb2(L)6(H2O)4][Symbol: see text](NO3)6[Symbol: see text]L2[Symbol: see text](H2O)18 (1) and [Hg(L)Cl2]n (2), were obtained by the reaction of D-?-A (D?=?donor, ??=?conjugated spacer, A?=?acceptor) type pyridinium inner salt dye, trans-4-[(p-N,N-dimethylamino)styryl]-N-(2-propanoic-acid) pyridinium (L) with corresponding metal salts. Single crystal X-ray diffraction analyses reveal that compound 1 possesses dinuclear motif in which two Tb(III) ions are linked by four carboxylate groups while complex 2 exhibits 1D chain structure based on Hg(II) ions bridged by carboxylate groups. The linear and non-linear optical properties of complexes 1 and 2 have been studied. Both 1 and 2 exhibit intense single-photon excited fluorescence (SPEF) and two-photon excited fluorescence (TPEF) in the red range. Results show that the replacement of central ions from Hg(2+) to Tb(3+) influence the two-photon absorption cross-section significantly through increasing the density of the chromophore. However, the peak positions of two-photon excited fluorescence are only slightly affected. Compared with L molecule, complex 1 shows enhanced two-photon absorption cross-section and decreased fluorescent lifetime. PMID:25731815

Zhou, Yong-Hong; Wang, Na-Li; Miao, Ti-Fang; Wang, Juan-Gang; Wang, Zhe-Yu

2015-03-01

113

Synthesis and analysis of nickel dithiolene dyes in a nematic liquid crystal host. 1998 summer research program for high school juniors at the University of Rochester`s Laboratory for Laser Energetics: Student research reports  

SciTech Connect

The Liquid Crystal Point Diffraction Interferometer (LCPDI) can be employed to evaluate the Omega Laser system for optimum firing capabilities. This device utilizes a nickel dithiolene infrared absorbing liquid crystal dye dissolved in a liquid crystal host medium (Merck E7). Three nickel dithiolene dyes were characterized for both their solubility in the E7 host and their infrared spectral absorption.

Lippa, I. [Byron-Bergen High School, NY (United States)

1999-03-01

114

Back focal plane imaging of directional emission from dye molecules coupled to one-dimensional photonic crystals.  

PubMed

Bloch surface waves (BSWs) on one-dimensional photonic crystals (1DPCs) have been used to beam the fluorescence emission from the dye molecules. All dielectric 1DPC displays its low propagating loss, narrow resonance and the absence of absorption or quenching. In this paper, back focal plane imaging reveals that in addition to the BSW mode, a guided mode and a cavity mode also exist in the 1DPC which all couple with the excited dye molecules. The appearance of these modes is sensitive to the wavelength of the fluorescence and alters the beaming effect by the 1DPC. Numerical simulations verify the existence of these modes which are consistent with the experimental results. Comparisons between the Bloch surface wave coupled emission and surface plasmon coupled emission are also presented for a clearer understanding of the multilayered film enabled directional emission. PMID:24621990

Zhang, Douguo; Badugu, Ramachandram; Chen, Yikai; Yu, Sisheng; Yao, Peijun; Wang, Pei; Ming, Hai; Lakowicz, Joseph R

2014-04-11

115

Back focal plane imaging of directional emission from dye molecules coupled to one-dimensional photonic crystals  

PubMed Central

Bloch surface waves (BSWs) on one-dimensional photonic crystals (1DPC) have been used to beam the fluorescence emission from the dye molecules. All dielectric 1DPC displays its low propagating loss, narrow resonance and the absence of absorption or quenching. In this letter, back focal plane imaging reveals that in addition to the BSW mode, a guided mode and cavity mode also exist in the 1DPC which all couple with the excited dye molecules. The appearance of these modes is sensitive to the wavelength of the fluorescence and alters the beaming effect by the 1DPC. Numerical simulations verify the existence of these modes which are consistent with the experimental results. Comparisons between the Bloch surface wave-coupled emission (BWCE) and surface plasmon-coupled emission (SPCE) are also presented for a more clear understanding of the multilayered film-enabled directional emission. PMID:24621990

Zhang, Douguo; Badugu, Ramachandram; Chen, Yikai; Yu, Sisheng; Yao, Peijun; Wang, Pei; Ming, Hai; Lakowicz, Joseph R.

2014-01-01

116

The potential application of activated carbon from sewage sludge to organic dyes removal.  

PubMed

The objective of this research work was to study the potential application of activated carbon from sewage sludge to organic dye removal. Methylene blue and crystal violet were the two dyes investigated in the present study. Three activated carbons were produced from the exclusive sewage sludge (referred to as DS), the sludge with the additive of coconut husk (DC) and sludge with the additive of peanut shell (DP) respectively. They were characterized by their surface area and porosity and their surface chemistry structure. Adsorption studies were performed by the batch technique to obtain kinetic and equilibrium data. The results show that the three sludge-derived activated carbons had a developed porosity and marked content of surface functional groups. They exhibited a rapid three-stage adsorption process for both methylene blue and crystal violet. Their adsorption capacities for the two dyes were high, the carbon DP performed best in the adsorption whereas the carbon DC performed worst. It is therefore concluded that the activated carbons made from sewage sludge and its mixtures are promising for dye removal from aqueous streams. PMID:11380186

Graham, N; Chen, X G; Jayaseelan, S

2001-01-01

117

Plant-mediated synthesis of silver-nanocomposite as novel effective azo dye adsorbent  

NASA Astrophysics Data System (ADS)

Toxicity of textile effluent is a globally alarming issue nowadays. In order to address this problem, a cost-effective and environment-friendly technique for adsorption of toxic dyes has been introduced in this research. Firstly in this study, green synthesis of silver nanoparticles (AgNPs) having antibacterial efficacy, had been carried out using leaf extracts of Azadirachta indica as reducing as well as capping agent. This research idea was further extended for the development and application of a novel method of preparation of silver-nanocomposite using synthesized microwave-assisted AgNPs with soil as a novel nanocomposite to adsorb hazardous dyes. However, this nanocomposite was found to possess higher efficiency and adsorption capacity in comparison to soil as adsorbent for the removal of crystal violet dye under same experimental conditions. Additionally, it was also observed that use of this Ag-nanocomposite as adsorbent helped in achieving about 97.2 % removal of crystal violet dye from the effluent solution.

Satapathy, Mantosh Kumar; Banerjee, Priya; Das, Papita

2015-01-01

118

Pulse Modulation Of An Excimer Pumped Dye Laser  

NASA Astrophysics Data System (ADS)

The generation of subnanosecond dye laser pulses from an excimer pumped dye laser, using a saturable absorber, is investigated. Subnanosecond pulses from rhodamine 610 and rhodamine 640 dye lasers, using cresyl violet as a saturable absorber, are reported. Self-pulse modulation was also observed.

Efthimiopoulos, T.

1985-08-01

119

Enhanced light harvesting in dye-sensitized solar cells coupled with titania nanotube photonic crystals: a theoretical study.  

PubMed

Herein we present a theoretical analysis on the optical properties and the photocurrent enhancement of nanotube-based dye-sensitized solar cells (DSSCs) coupled with a TiO2 nanotube (NT) photonic crystal (PC). It is found that the introduction of a TiO2 nanotube PC produces both Bragg mirror effect and Fabry-Perot cavity behavior, leading to a significant enhancement of light harvesting for photons in the photonic bandgap and at the two band edges. In addition, an increased amount of surface-anchored dye due to the larger surface area in the NT PC layer also causes absorption enhancement in the whole visible spectrum. The effects of structural parameters of the PC, such as the thickness of the PC layer, the axial lattice constant, the diameter of the nanotube, and light incident angle, on the optical properties and photocurrent magnification are thoroughly studied. The optimum structural parameters are proposed, which not only provide guidance but also offer further opportunities in the design and applications of TiO2 nanotube photonic crystals. PMID:24313334

Guo, Min; Yong, Zehui; Xie, Keyu; Lin, Jia; Wang, Yu; Huang, Haitao

2013-12-26

120

Effect of some operational parameters on textile dye biodegradation in a sequential batch reactor  

Microsoft Academic Search

The combination of anaerobic and aerobic periods in the operation cycle of a Sequencing Batch Reactor (SBR) was chosen to study biological color removal from simulated textile effluents containing reactive, sulfonated, monoazo and diazo dyes, respectively, Remazol Brilliant Violet 5R and Remazol Black B. 90% color removal was obtained for the violet dye in a 24-h cycle with a Sludge

N. D Lourenço; J. M Novais; H. M Pinheiro

2001-01-01

121

Ultrafast electron injection from excited dye molecules into semiconductor electrodes  

NASA Astrophysics Data System (ADS)

Fluorescence decay of adsorbed dye molecules is measured on semiconductor electrodes where their stationary photoelectrochemical current approaches the yield of one electron per absorbed photon, also on solids where injection cannot occur and finally on a semiconductor where the current yield is low. At very low coverages, ?·~10 -2, the fluorescence decay of an efficiently injecting ruthenium complex is faster than 10 ps on a polycrystalline TiO 2 electrode and also that of the efficiently injecting cresyl violet monomer on single crystal n-SnS 2. At higher coverage ??0,1, fluorescence decay is not only controlled by electron injection, exhibiting a very different dependence on dye coverage for different dye/semiconductor combinations with high injection yields at low coverages. Ultrafast and fast electron injection from vibronic excited dye monomers into the wide conduction band of semiconductors is discussed. The yield of stationary photoelectrochemical injection currents is discussed for different dye coverages taking into account the measured fluorescence decay behavior.

Eichberger, R.; Willig, F.

1990-02-01

122

Electrophoretic deposition of TiO2 nanoparticles using organic dyes.  

PubMed

Electrophoretic deposition method has been developed for the deposition of TiO(2) nanoparticles modified with organic dyes. Alizarin red, alizarin yellow and pyrocatechol violet dyes were used for the dispersion and charging of TiO(2) in ethanol and anodic electrophoretic deposition of TiO(2) films. The deposition yield was varied by the variation of dye concentration in suspensions and deposition time. Aurintricarboxylic acid dye was used for the deposition of TiO(2) from aqueous suspensions. It was found that thin films of pure aurintricarboxylic acid and composite aurintricarboxylic acid TiO(2) films can be obtained. The deposition yield was studied by quartz crystal microbalance. Dye film thickness was varied in the range of 0.1-2 ?m by variation in the deposition time at a constant voltage. The composition of the films and the amount of the deposited material can be varied by the variation of TiO(2) and dye concentration in suspensions and deposition time. The films were studied by Fourier transform infrared spectroscopy, thermogravimetric analysis, differential thermal analysis and electron microscopy. The deposition mechanisms were discussed. The electrophoretic deposition method offers advantages for the fabrication of dye-sensitized TiO(2) films. PMID:22204967

Sun, Y; Ata, M S; Zhitomirsky, I

2012-03-01

123

Photo-patterning micro-mirror devices using azo dye-doped cholesteric liquid crystals  

E-print Network

cholesteric liquid crystal display," J. Appl. Phys., 81, 1063-1066 (1997). 5. S. T. Wu and D. K. Yang, Reflective Liquid Crystal Displays (Wiley, New York, 2001). 6. I. Shiyanovskaya, A. Khan, S. Green, G. Magyar. Capurso, "Single-substrate cholesteric liquid crystal displays by colloidal self-assembly," Appl. Phys

Wu, Shin-Tson

124

Rapid Charge Transport in Dye-Sensitized Solar Cells Made from Vertically Aligned Single-Crystal Rutile TiO2 Nanowires  

SciTech Connect

A rapid solvothermal approach was used to synthesize aligned 1D single-crystal rutile TiO2 nanowire (NW) arrays on transparent conducting substrates as electrodes for dye-sensitized solar cells. The NW arrays showed a more than 200 times faster charge transport (see picture) and a factor four lower defect state density than conventional rutile nanoparticle films.

Feng, X.; Zhu, K.; Frank, A. J.; Grimes, C. A.; Mallouk, T. E.

2012-03-12

125

Fluorescence screening of leucomalachite green and leucogentian violet residues in catfish  

Technology Transfer Automated Retrieval System (TEKTRAN)

The tripheylmethane dyes malachite green (MG) and gentian violet (GV) are effective fungicides, ectoparasiticides and disinfectants in aquaculture. This practice may leave toxic residues in seafood which is not allowed by FDA and many regulatory agencies worldwide. In this work, residues of their me...

126

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2012 CFR

...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity...Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in...

2012-04-01

127

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2011 CFR

...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity...Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in...

2011-04-01

128

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2013 CFR

...OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2775 Manganese violet. (a) Identity...Manganese violet is safe for use in coloring cosmetics generally, including cosmetics applied to the area of the eye, in...

2013-04-01

129

Enhanced optical, dielectric and piezoelectric behavior in dye doped zinc tris-thiourea sulphate (ZTS) single crystals  

NASA Astrophysics Data System (ADS)

Pure and 0.1 mol% amaranth dye doped zinc tris-thiourea sulphate (ZTS) crystals were grown by slow evaporation technique. Orthorhombic structures with changed morphology were observed. Various functional groups present were identified by FTIR and Raman analysis. UV-Vis spectra shows wide transmittance and increased optical band gap from 4.54 to 4.59 eV, with lower extinction coefficient in doped case. In photoluminescence measurement, an intense peak at 416 nm was observed for doped ZTS. Dielectric constant value increases from 3.28 to 9.40 at 1 kHz with doping. Piezoelectric coefficient d33 is also enhanced from 0.24 to 3 pC/N.

Bhandari, Sonia; Sinha, Nidhi; Ray, Geeta; Kumar, Binay

2014-01-01

130

Conducting glasses recovered from thin film transistor liquid crystal display wastes for dye-sensitized solar cell cathodes.  

PubMed

Transparent conductive glasses such as thin film transistor (TFT) array and colour filter glasses were recovered from the TFT-liquid crystal display panel wastes by dismantling and sonic cleaning. Noble metals (i.e. platinum (Pt)) and indium tin oxide (ITO) are generally used in the cathode of a dye-sensitized solar cell (DSSC). To reduce the DSSC cost, Pt was replaced with nano nickel-encapsulated carbon-shell (Ni@C) nanoparticles, which were prepared by carbonization of Ni(2+)-?-cyclodextrin at 673?K for 2?h. The recovered conductive glasses were used in the DSSC electrodes in the substitution of relatively expensive ITO. Interestingly, the efficiency of the DSSC having the Ni@C-coated cathode is as high as 2.54%. Moreover, the cost of the DSSC using the recovered materials can be reduced by at least 24%. PMID:25399759

Chen, C-C; Chang, F-C; Peng, C Y; Wang, H Paul

2014-11-27

131

Light-scattering experiments in dye-doped liquid crystals both to determine crystal parameters and to construct consistent neural network empirical physical formulas for scattering amplitudes  

NASA Astrophysics Data System (ADS)

The aim of this paper is two-fold. Firstly, static laser light-scattering amplitude measurements in azo-dye doped nematic liquid crystals (NLCs) were made versus scattering angle, temperature and applied bias voltage. Three NLC parameters were determined: the elastic constant ratios K11/K22 by regression, phase transition temperatures, and Freedericksz voltages from the graphs. They were all doping ratio dependent. Secondly, as a novel approach, by a nonlinear universal function approximator layered feedforward neural network (LFNN) we constructed an explicit form of empirical physical formulas (EPFs) for theoretically unknown nonlinear azo-dye doped NLC scattering amplitude functions. Excellent LFNN test set (i.e. yet-to-be measured experimental data) predictions prove that the constructed LFNN-EPPs estimate unknown amplitude functions consistently. The LFFN-EPFs, too, confirmed the doping-ratio dependency. Also, comparing LFNN and regression amplitude fits, the LFNN fits were significantly better. In conclusion, physical laws embedded in the physical data can be consistently extracted by LFNN. One major potential application in the nonlinear optics domain is that these LFNN-EPFs, by differentiation, integration, minimization, etc., can be used to obtain further NLC scattering amplitude related molecular structural physical quantities. This could in turn help us to develop new nonlinear optical materials.

Yildiz, Nihat; San, Sait Eren; Polat, Ömer

2011-04-01

132

All-optical switching of diffraction gratings infiltrated with dye-doped liquid crystals  

NASA Astrophysics Data System (ADS)

We report the realization and the characterization of an all-optical switching device based on a transmission grating recorded in a polymeric substrate infiltrated with a methyl red-doped liquid crystal. The properties of this highly nonlinear mixture are exploited to modulate the diffraction of the grating by a pump beam when a static electric field is applied. The behavior of the device is in agreement with the existing model for methyl red-doped liquid crystals.

Lucchetta, D. E.; Vita, F.; Simoni, F.

2010-12-01

133

Optimization of lasing in an inverted-opal titania photonic crystal cavity as an organic solid-state dye-doped laser.  

PubMed

Lasing performance of a dye-doped laser by encapsulating orange fluorescent dye 4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) with different concentrations in a highly ordered three-dimensional (3D) inverted-opal titania (TiO2) photonic crystal (PC) microcavity was studied. The lasing threshold and laser quality were improved by optimizing the concentration of the laser dye DCM. When the concentration of DCM is optimized to 10-4??mol/l, the photoluminescence (PL) efficiency of DCM is sufficient to achieve lasing emission and meanwhile no fluorescence quantum quenching occurs. Therefore, the emission spectrum was greatly narrowed and the threshold was significantly improved, which reached 0.8??mJ?pulse-1?cm-2. Our findings are promising results toward the realization of fabricating a highly efficient low-threshold organic laser. PMID:25402981

Zhang, Dingke; Chen, Shijian; Jiang, Maohua; Ye, Lijuan

2014-11-10

134

Light-controlled electric Freedericksz threshold in dye doped liquid crystals  

SciTech Connect

We report the results of measurements of the threshold of Freedericksz transition in a nematic liquid crystal doped by Methyl-red. We show that in case of dc field the threshold voltage can decrease or increase depending on the light dose, due to the light-induced desorption and adsorption of charge complexes from and on the irradiated surface, that has been recently demonstrated. This effect has the potential to be exploited in optical devices such as liquid crystal microlenses and spatial light modulators.

Lucchetti, L.; Catani, L.; Simoni, F. [Dipartimento di Scienze e Ingegneria della Materia, dell'Ambiente ed Urbanistica and CNISM Università Politecnica delle Marche, Ancona (Italy)

2014-05-28

135

Method for colorimetric detection of double-stranded nucleic acid using leuco triphenylmethane dyes.  

PubMed

Because loop-mediated isothermal amplification (LAMP) can amplify substantial amounts of DNA under isothermal conditions, its applications for simple genetic testing have attracted considerable attention. A positive LAMP reaction is indicated by the turbidity caused by by-products or by the color change after adding a metallochromic indicator to the reaction solution, but these methods have certain limitations. Leuco crystal violet (LCV), a colorless dye obtained after sodium sulfite treatment of crystal violet (CV), was used as a new colorimetric method for detecting LAMP. LCV is reconverted into CV through contact with double-stranded DNA (dsDNA). Therefore, the positive reaction of LAMP is indicated by color change from colorless to violet. The assay is sensitive enough to detect LAMP products, with a detection limit of 7.1ng/?l for dsDNA. It is also highly selective to dsDNA, and interference with single-stranded DNA and deoxynucleotide triphosphates (dNTPs) is not observed. LCV facilitates direct colorimetric detection of the main product rather than a by-product of the LAMP reaction; therefore, this method can be used under various reaction conditions such as those with added pyrophosphatase in solution. This colorimetric LAMP detection method using LCV is useful for point-of-care genetic testing given its simplicity. PMID:25575759

Miyamoto, Shigehiko; Sano, Sotaro; Takahashi, Koji; Jikihara, Takaaki

2015-03-15

136

In vivo multispectral photoacoustic and photothermal flow cytometry with multicolor dyes: a potential for real-time assessment of circulation, dye-cell interaction, and blood volume.  

PubMed

Recently, photoacoustic (PA) flow cytometry (PAFC) has been developed for in vivo detection of circulating tumor cells and bacteria targeted by nanoparticles. Here, we propose multispectral PAFC with multiple dyes having distinctive absorption spectra as multicolor PA contrast agents. As a first step of our proof-of-concept, we characterized high-speed PAFC capability to monitor the clearance of three dyes (Indocyanine Green [ICG], Methylene Blue [MB], and Trypan Blue [TB]) in an animal model in vivo and in real time. We observed strong dynamic PA signal fluctuations, which can be associated with interactions of dyes with circulating blood cells and plasma proteins. PAFC demonstrated enumeration of circulating red and white blood cells labeled with ICG and MB, respectively, and detection of rare dead cells uptaking TB directly in bloodstream. The possibility for accurate measurements of various dye concentrations including Crystal Violet and Brilliant Green were verified in vitro using complementary to PAFC photothermal (PT) technique and spectrophotometry under batch and flow conditions. We further analyze the potential of integrated PAFC/PT spectroscopy with multiple dyes for rapid and accurate measurements of circulating blood volume without a priori information on hemoglobin content, which is impossible with existing optical techniques. This is important in many medical conditions including surgery and trauma with extensive blood loss, rapid fluid administration, and transfusion of red blood cells. The potential for developing a robust clinical PAFC prototype that is safe for human, and its applications for studying the liver function are further highlighted. PMID:21905207

Proskurnin, Mikhail A; Zhidkova, Tatyana V; Volkov, Dmitry S; Sarimollaoglu, Mustafa; Galanzha, Ekaterina I; Mock, Donald; Nedosekin, Dmitry A; Zharov, Vladimir P

2011-10-01

137

Chlorophyll J-aggregates: from bioinspired dye stacks to nanotubes, liquid crystals, and biosupramolecular electronics.  

PubMed

Among the natural light-harvesting (LH) systems, those of green sulfur and nonsulfur photosynthetic bacteria are exceptional because they lack the support of a protein matrix. Instead, these so-called chlorosomes are based solely on "pigments". These are self-assembled bacteriochlorophyll c, d, and e derivatives, which consist of a chlorophyll skeleton bearing a 3(1)-hydroxy functional group. Chemists consider the latter as an essential structural unit to direct the formation of light-harvesting self-assembled dye aggregates with J-type excitonic coupling. The intriguing properties of chlorosomal J-type aggregates, particularly narrow red-shifted absorption bands, compared with monomers and their ability to delocalize and migrate excitons, have inspired intense research activities toward synthetic analogues in this field. The ultimate goal of this research field is the development of (opto-)electronic devices based on the architectural principle of chlorosomal LH systems. In this regard, the challenge is to develop small, functional building blocks with appropriate substituents that are preprogrammed to self-assemble across different length scales and to emulate functions of natural LH systems or to realize entirely new functions beyond those found in nature. In this Account, we highlight our achievements in the past decade with semisynthetic zinc chlorins (ZnChls) as model compounds of bacteriochlorophylls obtained from the naturally most abundant chlorin precursor: chlorophyll a. To begin, we explore how supramolecular strategies involving ?-stacking, hydrogen bonding, and metal-oxygen coordination can be used to design ZnChl-based molecular stack, tube, and liquid crystalline assemblies conducive to charge and energy transport. Our design principle is based on the bioinspired functionalization of the 3(1)-position of ZnChl with a hydroxy or methoxy group; the former gives rise to tubular assemblies, whereas the latter induces stack assemblies. Functionalization of the 17(2)-position with esterified hydrophilic or hydrophobic chains, dendron-wedge substituents, and chromophores having complementary optical properties such as naphthalene bisimides (NBIs) is used to modulate the self-assembly of ZnChl dyes. The resulting assemblies exhibit enhanced charge transport and energy transfer abilities. We have used UV/vis, circular dichroism (CD), fluorescence spectroscopy, and dynamic light scattering (DLS) for the characterization of these assemblies in solution. In addition, we have studied assembly morphologies by atomic force microscopy (AFM), scanning tunneling microscopy (STM), transmission electron microscopy (TEM), and cryogenic-TEM. Crystallographic techniques such as powder X-ray and solid-state NMR have been used to explain the precise long- and short-range packing of dyes in these assemblies. Finally, functional properties such as charge and energy transport have been explored by pulse radiolysis time-resolved microwave conductivity (PR-TRMC), conductive AFM, and time-resolved fluorescence spectroscopy. The design principles discussed in this Account are important steps toward the utilization of these materials in biosupramolecular electronics and photonics in the future. PMID:23865851

Sengupta, Sanchita; Würthner, Frank

2013-11-19

138

Inhalation toxicology of red and violet mixtures. Chamber concentration and particle-size distribution report  

SciTech Connect

An inhalation exposure facility was developed at the U.S. EPA, RTP, NC to conduct inhalation exposures of rodents and guinea pigs to dye mixtures used by the U.S. Army in the manufacture of smoke munitions. Initially, an evaluation of the prototype chamber aerosol homogeneity was conducted to determine the uniformity and reproducibility of the concentration and particle size of dye aerosol throughout the breathing zone of the test animals. The three dyes, DR11, SR1, and DB3, were chemically analyzed for purity and optically examined for size and shape. All pure dyes appeared to be stable at room temperature except DB3, which decomposes if not stored at 4 C. The particle size ranges varied for each pure dye and structures were either amorphous (azo dye) or crystalline (anthraquinone dyes). The bulk red and violet dye mixtures were analyzed for composition. The chemical analysis of the relative composition of each dye mixture, collected by cascade impactor sampling, revealed fractionation of the mixtures into component dyes.

Higuchi, M.A.; Davies, D.W.

1991-07-01

139

Decolorization of Alizarin Red and other synthetic dyes by a recombinant laccase from Pichia pastoris.  

PubMed

A cDNA encoding for a laccase was isolated from the white-rot fungus Lenzites gibbosa by RT-PCR and expressed in the Pichia pastoris. The laccase native signal peptide efficiently directed the secretion of the recombinant laccase in an active form. Factors influencing laccase expression, such as pH, cultivation temperature, copper concentration and methanol concentration, were optimized. The recombinant enzyme was purified to electrophoretic homogeneity, and was estimated to have a MW of ~61.5 kDa. The purified enzyme behaved similarly to the native laccase produced by L. gibbosa and efficiently decolorized Alizarin Red, Neutral Red, Congo Red and Crystal Violet, without the addition of redox mediators. The decolorization capacity of this recombinant enzyme suggests that it could be a useful biocatalyst for the treatment of dye-containing effluents. This study is the first report on the synthetic dye decolorization by a recombinant L. gibbosa laccase. PMID:24078122

Zheng, Miaomiao; Chi, Yujie; Yi, Hongwei; Shao, Shuli

2014-01-01

140

Ferrofluid based dispersive-solid phase extraction for spectrophotometric determination of dyes.  

PubMed

For the first time, ferrofluid based dispersive-solid phase extraction (D-SPE) has been applied for determination of trace levels of dyes in aqueous and fish samples. The contaminant used as a model compound was crystal violet (CV), a cationic dye, and was preconcentrated without any derivatization or ion-pair formation. The method is based on rapid injection of ferrofluid into the aqueous sample by a syringe. The sample preparation time is decreased by the fact that the sorbent dispersed in the bulk solution and extraction can be achieved very fast. In this way, the separation of sorbent from the aqueous bulk was achieved by a magnet, and no centrifugation is required. These significant features which obtained with this method are of key interest for routine trace laboratory analysis. The influence of different variables on D-SPE was investigated. Under optimum conditions, the calibration graph was linear over the range of 3.3-90 ?g L(-1), and the enrichment factor (EF) 267 was obtained. Detection limit was 1.51 ?g L(-1) (n=7), and the relative standard deviation of 5.6% at 50 ng mL(-1) was obtained (n=7). The proposed method was successfully applied for the determination of crystal violet in various samples. PMID:23849184

Davudabadi Farahani, Malihe; Shemirani, Farzaneh

2013-10-01

141

Microgap ultra-violet detector  

DOEpatents

A microgap ultra-violet detector of photons with wavelengths less than 400 run (4,000 Angstroms) which comprises an anode and a cathode separated by a gas-filled gap and having an electric field placed across the gap is disclosed. Either the anode or the cathode is semi-transparent to UV light. Upon a UV photon striking the cathode an electron is expelled and accelerated across the gap by the electric field causing interactions with other electrons to create an electron avalanche which contacts the anode. The electron avalanche is detected and converted to an output pulse. 2 figs.

Wuest, C.R.; Bionta, R.M.

1994-09-20

142

Colour removal from a simulated dye wastewater using a two-phase Anaerobic packed bed reactor  

Microsoft Academic Search

In recent years, rapid technological advances in the textile and dyeing industry have yielded benefits to society but have also generated new and significant environmental problems. The treatment alternatives applicable for the removal of colour vary, depending upon the type of dye wastewater. A synthetic, simulated mixed dye waste (Basic Yellow 28, Basic Yellow 21, Basic Red 18.1, Basic Violet

A. Mahdavi Talarposhti; T. Donnelly; G. K. Anderson

2001-01-01

143

Dye adsorption on mesoporous activated carbon fiber obtained from pitch containing yttrium complex  

Microsoft Academic Search

The adsorption of acid dyes (Acid Blue 9, Acid Blue 74, Acid Orange 10, and Acid Orange 51), direct dyes (Direct Black 19, Direct Yellow 11, and Direct Yellow 50), and basic dyes (Basic Brown 1 and Basic Violet 3) on a highly mesoporous activated carbon fiber (Y-ACF) obtained from pitch containing yttrium acetylacetonate was investigated in terms of size

Hisashi Tamai; Takeshi Yoshida; Masahiko Sasaki

1999-01-01

144

Bichromophoric dyes for wavelength shifting of dye-protein fluoromodules.  

PubMed

Dye-protein fluoromodules consist of fluorogenic dyes and single chain antibody fragments that form brightly fluorescent noncovalent complexes. This report describes two new bichromophoric dyes that extend the range of wavelengths of excitation or emission of existing fluoromodules. In one case, a fluorogenic thiazole orange (TO) was attached to an energy acceptor dye, Cy5. Upon binding to a protein that recognizes TO, red emission due to efficient energy transfer from TO to Cy5 replaces the green emission observed for monochromophoric TO bound to the same protein. Separately, TO was attached to a coumarin that serves as an energy donor. The same green emission is observed for coumarin-TO and TO bound to a protein, but efficient energy transfer allows violet excitation of coumarin-TO, versus longer wavelength, blue excitation of monochromophoric TO. Both bichromophores exhibit low nanomolar KD values for their respective proteins, >95% energy transfer efficiency and high fluorescence quantum yields. PMID:25679477

Pham, Ha H; Szent-Gyorgyi, Christopher; Brotherton, Wendy L; Schmidt, Brigitte F; Zanotti, Kimberly J; Waggoner, Alan S; Armitage, Bruce A

2015-03-11

145

Pulsed electric linear dichroism of triphenylmethane dyes adsorbed on montmorillonite K10 in aqueous media  

SciTech Connect

Electric linear dichroism (ELD) spectra of two cationic triphenylmethane dyes, crystal violet (CV) and malachite green (MG), bound to sodium montmorillonite K10 (MK-10) were studied at 20 C in aqueous media at two mixing ratios, D/S, of 0.10 and 0.24 in the 700- to 400 nm wavelength region and in the applied electric field strength range between 0 and 3 kV/cm. The specific parallel and perpendicular dichroism ({Delta}A{sub {parallel}}/A and {Delta}A{sub {perpendicular}}/A) spectra of dye-adsorbed MK-10 suspension were measured at a fixed field strength with an apparatus equipped with a 512-channel photodiode array detector. By changing the field strength over a wide range, a series of the reduced dichroism values of the bound dyes were measured at a fixed wavelength. By fitting these dichroism values to theoretical orientation functions, the intrinsic reduced dichroism ({Delta}A/A){sub int} spectra at the limiting high fields (ELD spectrum) were determined for CV and MG bound to MK-10. No appreciable difference was observed at the two D/S values. The ELD spectra of these bound dyes are undulatory but never constant, throughout their absorption region; thus, the dye plane does not lie flatly either on the surface or between layers of MK-10 particle.

Yamaoka, Kiwamu; Sasai, Ryo

2000-05-01

146

Copper-ligand complex for the decolorization of synthetic dyes.  

PubMed

The reaction system containing Cu(II), hydrogen peroxide and D-arabinono-1,4-lactone was found to be effective in the decolorization and reduction of toxicity of azo, thiazine-, triphenylmethane- and anthraquinone-based synthetic dyes. More than 85% decolorization was obtained with 100ppm Acridine Orange, Azure B, Chicago Sky Blue 6B, Crystal Violet, Evans Blue, Poly B-411, Reactive Blue 2, Reactive Blue 5, and Remazol Brilliant Blue R incubated for 24h in the presence of 10mM CuSO(4), 20mM D-arabinono-1,4-lactone and 80 mM H(2)O(2). The rate of decolorization was not affected by pH in the range of 3-9. The rapid decolorization was accompanied by a fast decomposition of H(2)O(2) in the reaction mixture and by a fast production of hydroxyl radicals. PMID:15504481

Verma, Pradeep; Baldrian, Petr; Gabriel, Jirí; Trnka, Tomás; Nerud, Frantisek

2004-12-01

147

Distributed feedback lasing from electrically tunable dye-doped polymer–liquid crystal transmission gratings  

NASA Astrophysics Data System (ADS)

In the present work we report low-threshold distributed feedback (DFB) lasing from electrically tunable holographic polymer–liquid crystal transmission gratings of POLIPHEM type doped with pyrromethene 567. Due to their uniform droplet-free micro-morphology, the POLIPHEM gratings possess high diffraction efficiency and excellent optical quality. Second-order lasing with a threshold of ~0.8?µJ/pulse and a bandwidth of ~1?nm was achieved under the excitation of a frequency-doubled Nd:YAG laser operating at 532?nm. The laser emission wavelength was tuned from 572–625?nm by varying the grating period. Application of an electric field switches off or tunes the lasing intensity. An electrically-induced blue-shift of the output laser emission was observed.

Sakhno, O. V.; Gritsai, Y.; Stumpe, J.

2014-11-01

148

Fast Optical Recording of Polarization Holographic Grating Based on an Azo-Dye-Doped Polymer-Ball-Type Polymer-Dispersed Liquid Crystal Film  

NASA Astrophysics Data System (ADS)

This work reports a fast optical recording material based on an azo-dye-doped polymer-ball-type polymer-dispersed liquid crystal film. A memory polarization holographic grating is written on the film and formed in ˜2 ms using two writing beams derived from a Q-switched Nd:YAG SHG pulse laser (?w=532 nm) with duration of 20 ns and a total energy density of ˜15 mJ/cm2. The polarization grating (PG) is created from the photo-excited dye molecules. These photo-excited dye molecules undergo three-dimensional rotation, diffusion, then adsorb on the surface of the polymer balls, and finally induce the reorientation of the LCs. Polarization analysis of the PG reveals that it diffracts the linearly polarized incident light into beams with different polarizations. A model based on the Jones matrix method is also proposed and closely fits the experiment results. Experimental results indicate that the PG is electrically switched (˜3 V/?m). The PG can be erased partially by thermal treatment. We speculate that the weakly-adsorbed dyes desorb from the surfaces of the polymer balls owing to thermal disturbance, causing partial grating erasion.

Fuh, Andy Ying-Guey; Lee, Chia-Rong; Cheng, Ko-Ting

2003-07-01

149

Electronic absorption spectra of cresyl violet acetate in anisotropic and isotropic solvents  

NASA Astrophysics Data System (ADS)

The isotropic and anisotropic solvation characteristics of cresyl violet acetate (CVA) were investigated in isotropic liquid solutions and in polar nematic matrices as a function of the solvent type and concentration. The interaction of the ionic dye with the anisotropic surrounding and with that of the isotropic solvents was investigated and compared. The experimental result suggests that the nematic liquid crystalline solvents might create stronger solvation than the isotropic solvents. The spectral shifts were correlated by the solvent permittivity and Kamlet-Taft parameters. The polarized absorption spectra of cresyl violet acetate were measured between 400 and 800 nm and the dichroic ratio R and degree of anisotropy S of this dye in the liquid crystalline host determined.

Jafari, A.; Ghanadzadeh, A.; Tajalli, H.; Yeganeh, M.; Moghadam, M.

2007-03-01

150

Femtosecond excited state relaxation of dye molecules in solution  

NASA Astrophysics Data System (ADS)

The bleaching dynamics of organic dye molecules in solution have been investigated using 70 fs pulses from a colliding pulse mode-locked ring dye laser. In addition to ground state relaxation on a nanosecond time scale, a fast partial recovery is observed. For the dyes Nile blue, oxazine 720, cresyl violet and rhodamine 640, this recovery is exponential, with relaxation times in the range 190-480 fs.

Weiner, A. M.; Ippen, E. P.

1985-03-01

151

Adsorption of dyes from aqueous solutions on activated charcoal  

Microsoft Academic Search

Adsorption of industrially important dyes namely bromophenol blue, alizarine red-S, methyl blue, methylene blue, eriochrome black-T, malachite green, phenol red and methyl violet from aqueous media on activated charcoal has been investigated. The effect of shaking time, pH and temperature on the adsorption behaviour of these dyes has been studied. It was noted that adsorption of all the dyes on

Muhammad J. Iqbal; Muhammad N. Ashiq

2007-01-01

152

Toxicity of imine-iminium dyes and pigments: electron transfer, radicals, oxidative stress and other physiological effects.  

PubMed

Although conjugation is well known as an important contributor to color, there is scant recognition concerning involvement of imine and iminium functions in the physiological effects of this class of dyes and pigments. The group includes the dyes methylene blue, rhodamine, malachite green, fuchsin, crystal violet, auramine and cyanins, in addition to the pigments consisting of pyocyanine, phthalocyanine and pheophytin. The physiological effects consist of both toxicity and beneficial aspects. The unifying theme of electron transfer-reactive oxygen species-oxidative stress is used as the rationale in both cases. Toxicity is frequently prevented or alleviated by antioxidants. The apparent dichotomy of methylene blue action as both oxidant and antioxidant is rationalized based on similar previous cases. This mechanistic approach may have practical benefit. This review is important in conveying, for the first time, a unifying mechanism for toxicity based on electron transfer-reactive oxygen species-oxidative stress arising from imine-iminium. PMID:24852913

Kovacic, Peter; Somanathan, Ratnasamy

2014-08-01

153

Photoinduced reordering in thin azo-dye films and light-induced reorientation dynamics of the nematic liquid-crystal easy axis.  

PubMed

We theoretically study the kinetics of photoinduced reordering triggered by linearly polarized (LP) reorienting light in thin azo-dye films that were initially illuminated with LP ultraviolet pumping beam. The process of reordering is treated as a rotational diffusion of molecules in the light intensity-dependent mean-field potential. The two-dimensional diffusion model which is based on the free energy rotational Fokker-Planck equation and describes the regime of in-plane reorientation is generalized to analyze the dynamics of the azo-dye order parameter tensor at varying polarization azimuth of the reorienting light. It is found that, in the photosteady state, the intensity of LP reorienting light determines the scalar order parameter (the largest eigenvalue of the order parameter tensor), whereas the steady state orientation of the corresponding eigenvector (the in-plane principal axis) depends solely on the polarization azimuth. We show that, under certain conditions, reorientation takes place only if the reorienting light intensity exceeds its critical value. Such threshold behavior is predicted to occur in the bistability region provided that the initial principal axis lies in the polarization plane of reorienting light. The model is used to interpret the experimental data on the light-induced azimuthal gliding of the liquid-crystal easy axis on photoaligned azo-dye substrates. PMID:23005436

Kiselev, Alexei D; Chigrinov, V G; Pasechnik, S V; Dubtsov, A V

2012-07-01

154

Biodegradation of azo and phthalocyanine dyes by Trametes versicolor and Bjerkandera adusta  

Microsoft Academic Search

Eighteen fungal strains, known for their ability to degrade lignocellulosic material or lignin derivatives, were screened\\u000a for their potential to decolorize commercially used reactive textile dyes. Three azo dyes, Reactive Orange 96, Reactive Violet\\u000a 5 and Reactive Black 5, and two phthalocyanine dyes, Reactive Blue 15 and Reactive Blue 38, were chosen as representatives\\u000a of commercially used reactive dyes. From

A. Heinfling; M. Bergbauer; U. Szewzyk

1997-01-01

155

21 CFR 73.2775 - Manganese violet.  

Code of Federal Regulations, 2014 CFR

...Identity. The color additive manganese violet...be avoided by good manufacturing practice: Ash...filtrate of 10 grams color additive (shaken occasionally...consistent with good manufacturing practice. (d) Labeling. The color additive and any mixture...

2014-04-01

156

Fluorescence Dynamics of Dye Probes in Micelles Nakul C. Maiti, M. M. G. Krishna, P. J. Britto, and N. Periasamy*  

E-print Network

depolarization dynamics of organic fluorescent dye probes (nile red, cresyl violet, DODCI, rhodamine B, and rhodamine DPPE) were studied in cationic, anionic, and neutral micelles by picosecond time-resolved single

Mallela, Krishna M. G.

157

Origin and evolution of a peraluminous silicic ignimbrite suite: The Violet Town Volcanics  

Microsoft Academic Search

The Violet Town Volcanics are a 373 Ma old, comagmatic, S-type volcanic sequence mainly comprising crystal-rich intracaldera ignimbrites. Rock types vary from rhyolites to rhyodacites, all containing magmatic cordierite and garnet phenocrysts. Variation in the suite is primarily due to fractionation of early-crystallized quartz, plagioclase and biotite (plus minor accessory phases) in a high-level magma chamber prior to eruption. Early

John D. Clemens; Victor J. Wall

1984-01-01

158

Dye-Sensitized Approaches to Photovoltaics  

NASA Astrophysics Data System (ADS)

Sensitization of wide band-gap semiconductors to photons of energy less than the band-gap is a key step in two technically important processes - panchromatic photography and photoelectrochemical solar cells. In both cases the photosensitive species is not the semiconductor - silver halide or metal oxide - but rather an electrochemically active dye. The gap between the highest occupied molecular level (HOMO) and the lowest unoccupied molecular level (LUMO) is less than the band-gap of the semiconductor with which it is associated. It can therefore absorb light of a wavelength longer than that to which the semiconductor itself is sensitive. The electrochemical process is initiated when the dye molecule relaxes from its photoexcited level by electron injection into the semiconductor, which therefore acts as a photoanode. If the dye is in contact with a redox electrolyte, the negative charge represented by the lost electron can be recovered from the reduced state of the redox system, which in return is regenerated by charge transfer from a cathode. An external load completes the electrical circuit. The system therefore represents a conversion of the energy of absorbed photons into an electrical current by a regenerative device in every functional respect analogous to a solid-state photovoltaic cell. As in any engineering system, choice of materials, their optimization and their synergy are essential to efficient operation. While a semiconductor-electrolyte contact is analogous to a Schottky contact, in that a barrier is established between two materials of different conduction mechanism, with the possibility of optical absorption, charge carrier pair generation and separation, it should be remembered that the photogenerated valence band hole in the semiconductor represents a powerful oxidizing agent. Given that the band-gap is related to the strength and therefore the stability of chemical bonding within the semiconductor, for narrow-gap materials the most likely reaction of such a hole is the photocorrosion of the semiconductor itself. However, only relatively narrow band-gap materials have an effective optical absorption through the visible spectrum, towards and into the infra-red. Materials with an optimal band-gap match to the solar spectrum, of the order of 1.5eV, are therefore electrochemically unstable. A stable photoelectrochemical cell, without some process of optical sensitization, and necessarily using a wide-gap semiconductor is sensitive only to the ultra-violet limit of the visible spectrum. Over recent years a suitable combination of semiconductor and sensitizer has been identified and optimized, so that now a solar spectrum conversion efficiency of over 11% has been verified in a sensitized photoelectrochemical device. One key to such an efficient system is the suppression of recombination losses. When the excited dye relaxes by electron loss, the separated charge carriers find themselves on opposite sides of a phase barrier -- the electron within the solid-state semiconductor, the positive charge externally, in association with the dye molecule. There is no valence---band involvement in the process, so the system represents a majority-carrier device, avoiding one of the major loss mechanisms in conventional photovoltaics. In consequence also a highly-disordered, even porous, semiconductor structure is acceptable, enabling surface adsorption of a sufficient concentration of the dye to permit total optical absorption of incident light of photon energy greater than the HOMO-LUMO gap of the dye molecule. The accepted wide-band semiconductor for photoelectrochemical applications is titanium dioxide in the anatase crystal structure. The size of the nanocrystals making up the semiconductor photoanode can be determined by hydrothermal processing of a precursor sol, and the film can be deposited on a transparent conducting oxide (TCO) substrate by any convenient thin-film process such as screen printing or tape casting. The preferred dye system is inspired by the natural processes involving chlorophyll, the coloring

Grätzel, Michael

2008-03-01

159

Potential use of low-cost lignocellulosic waste for the removal of direct violet 51 from aqueous solution: equilibrium and breakthrough studies.  

PubMed

An efficient biosorbent, sugarcane bagasse was used in native, HCl-treated, and Na-alginate immobilized form for the removal of Direct Violet 51 dye from aqueous solutions. Batch study was performed to optimize important process parameters, such as pH, contact time, biosorbent dose, initial dye concentration, and temperature. Removal of Direct Violet 51 was found to be favorable at pH 2 with the biosorbent dose of 0.05 g. Biosorption process was found to be exothermic in nature. Maximum dye biosorption (39.6 mg/g) was achieved by using HCl-treated biomass. The pseudo-second-order kinetic and Langmuir adsorption isotherm models showed best fitness to the experimental data. Thermodynamic study was also performed to determine the feasibility of biosorption process. Continuous mode study was performed to optimize the important process parameters, such as bed height, flow rate, and initial dye concentration for maximum removal of Direct Violet 51 dye. The higher bed height, low flow rate, and high initial dye concentration were found to be the better conditions for maximum dye biosorption (17.28 mg/g). The linearized form of the Thomas model equation fitted well to the experimental data. The bed depth service time model was used to express the effect of bed height on breakthrough curves. Characterization of biosorbent was performed by scanning electron microscopy and Fourier transform infrared (FT-IR) analysis. The FT-IR spectral analyses showed the involvement of hydroxyl, carbonyl, and carboxyl groups in biosorption process. These results indicated that sugarcane bagasse biomass could be used as a novel biosorbent for the removal of Direct Violet 51 dye from real textile and related industries. PMID:24468968

Sadaf, Sana; Bhatti, Haq Nawaz; Nausheen, Sana; Noreen, Saima

2014-05-01

160

Adsorption behaviors of acid and basic dyes on crosslinked amphoteric starch  

Microsoft Academic Search

Crosslinked amphoteric starch with carboxymethyl and quaternary ammonium groups is investigated as an adsorbent for removal of both acid and basic dyes in solution. Acid Light Yellow 2G, Acid Red G, Methyl Green and Methyl Violet were used to study the adsorption behaviors under various parameters such as pH, dose of amphoteric starches, initial dye concentration, adsorption time and adsorption

Shimei Xu; Jingli Wang; Ronglan Wu; Jide Wang; Hong Li

2006-01-01

161

Use of cellulose-based wastes for adsorption of dyes from aqueous solutions  

Microsoft Academic Search

Low-cost banana and orange peels were prepared as adsorbents for the adsorption of dyes from aqueous solutions. Dye concentration and pH were varied. The adsorption capacities for both peels decreased in the order methyl orange (MO) > methylene blue (MB) > Rhodamine B (RB) > Congo red (CR) > methyl violet (MV) > amido black 10B (AB). The isotherm data

Gurusamy Annadurai; Ruey-Shin Juang; Duu-Jong Lee

2002-01-01

162

Resonant Rayleigh scattering for the determination of trace amounts of mercury (II) with thiocyanate and basic triphenylmethane dyes  

SciTech Connect

Intense resonance Rayleigh scattering (RRS) appears when mercury (II) reacts with thiocyanate and a basic triphenylmethane dye (BTPMD), such as crystal violet (CV), ethyl violet (EV), brilliant green (BG), malachite green (MG) or indine green (IG), to form an ion-association complex of the type (BTPMD){sub 2}[Hg(SCN){sub 4}]. The characteristics of RRS spectra of the ion-association complexes and suitable conditions for the reactions were investigated. The intensity of RRS is directly proportional to the concentration of mercury (II) in the range of 0--2.0 {micro}g/25 ml. The RRS methods have very high sensitivities for determination of mercury (II); their detection limits are between 1.68 ng/ml and 6.00 ng/ml on different dye systems. The effects of foreign ions and ways to improve the selectivity were studied. The new highly sensitive methods for the determination of trace amounts of mercury based on the RRS of the ion-association complexes have been developed.

Liu, S.; Liu, Z.; Zhou, G. [Southwest Normal Univ., Chongqing (China). Inst. of Environmental Chemistry

1998-05-01

163

Reversible suppression of second harmonic generation in dye-doped liquid crystal by light-induced thermal phase transition on sub-micrometer scale  

NASA Astrophysics Data System (ADS)

Optically controllable signals are fundamental to various applications from communication to super-resolution imaging. However, literature on non-fluorescent, nonlinear optical signals that can be reversibly turned on/off on a sub-micrometer scale is scant. In this work, we experimentally demonstrate a scheme for the reversible suppression of second harmonic generation (SHG) based on dye-doped nematic liquid crystal molecules. Under a pump (suppressing SHG) and probe (generating SHG) setup with a tightly focusing microscope and a time-gated detection, outstanding modulation depth (>80%) has been realized. Surprisingly, the mechanism of liquid crystal SHG switch on a sub-micrometer scale was found to be light-induced thermal phase transition as against optical Frederick's transition. Quantitative analysis of the optical nonlinearity ? ( 2 ) versus local heating shows an excellent agreement of SHG signal suppression as well as its dependence on the liquid crystal molecular order and phase change. Our work provides an innovative example of applying nonlinear optical properties of soft materials, and can be further optimized for all-optical modulation applications.

Zhuo, Guan-Yu; Chen, Kuan-Chieh; Lai, Kai-Wen; Wang, Chao-Ran; Chao, Chih-Yu; Chu, Shi-Wei

2015-02-01

164

Synthesis and application of TiO2 single-crystal nanorod arrays grown by multicycle hydrothermal for dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

TiO2 is a wide band gap semiconductor with important applications in photovoltaic cells. Vertically aligned TiO2 nanorod arrays (NRs) are grown on the fluorine-doped tin oxide (FTO) substrates by a multicycle hydrothermal synthesis process. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and selected-area electron diffraction (SAED). It is found that dye-sensitized solar cells (DSSCs) assembled by the as-prepared TiO2 single-crystal NRs exhibit different trends under the condition of different nucleation and growth concentrations. Optimum cell performance is obtained with high nucleation concentration and low growth cycle concentration. The efficiency enhancement is mainly attributed to the improved specific surface area of the nanorod.

Zhu, Jian-Jing; Zhao, Yu-Long; Zhu, Lei; Gu, Xiu-Quan; Qiang, Ying-Huai

2014-04-01

165

Dye Painting!  

ERIC Educational Resources Information Center

This resource provides practical instructions for applying color and design directly to fabric. Basic information about the dye painting process is given. The guide addresses the technical aspects of fabric dye and color use and offers suggestions for fabric manipulation and dye application in order to achieve various design effects. This…

Johnston, Ann

166

Role of Laccase and Low Molecular Weight Metabolites from Trametes versicolor in Dye Decolorization  

PubMed Central

The studies regarding decolorization of dyes by laccase may not only inform about the possible application of this enzyme for environmental purposes, but also may provide important information about its reaction mechanism and the influence of several factors that could be involved. In this paper, decolorization of crystal violet and phenol red was carried out with different fractions of extracellular liquids from Trametes versicolor cultures, in order to describe the role of laccase in this reaction. Moreover, the possible role of the low molecular weight metabolites (LMWMs) also produced by the fungus was evaluated. The results confirm the existence of a nonenzymatic decolorization factor, since the nonprotein fraction of the extracellular liquids from cultures of T. versicolor has shown decolorization capability. Several experiments were performed in order to identify the main compounds related to this ability, which are probably low molecular weight peroxide compounds. PMID:22566767

Moldes, Diego; Fernández-Fernández, María; Sanromán, M. Ángeles

2012-01-01

167

Role of laccase and low molecular weight metabolites from Trametes versicolor in dye decolorization.  

PubMed

The studies regarding decolorization of dyes by laccase may not only inform about the possible application of this enzyme for environmental purposes, but also may provide important information about its reaction mechanism and the influence of several factors that could be involved. In this paper, decolorization of crystal violet and phenol red was carried out with different fractions of extracellular liquids from Trametes versicolor cultures, in order to describe the role of laccase in this reaction. Moreover, the possible role of the low molecular weight metabolites (LMWMs) also produced by the fungus was evaluated. The results confirm the existence of a nonenzymatic decolorization factor, since the nonprotein fraction of the extracellular liquids from cultures of T. versicolor has shown decolorization capability. Several experiments were performed in order to identify the main compounds related to this ability, which are probably low molecular weight peroxide compounds. PMID:22566767

Moldes, Diego; Fernández-Fernández, María; Sanromán, M Ángeles

2012-01-01

168

Neighborhood competition in several violet populations  

Microsoft Academic Search

Research into local (neighborhood) competition has heretofore focused on either natural populations of long-lived woody plants or artifical populations of herbaceous annuals. To explore the usefulness of these techniques for herbaceous perennials, 1 applied them to 11 natural populations of 4 species of violet (Viola blanda, V. pallens, and V. incognita, alone and with V. adunca). Ramet density ranged from

D. M. Waller

1981-01-01

169

Effect of crystallization of Cu?ZnSnSxSe?-x counter electrode on the performance for efficient dye-sensitized solar cells.  

PubMed

Cu2ZnSnSxSe4-x (CZTSSe) counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) are commonly developed with porous structures, but their high surface area could also retard electron transport processes owing to the abundant grain boundaries. Herein, we employed a convenient solution method and a rapid heating process to prepare well crystalline CZTSSe CEs in DSSCs. The influence of crystallization of CZTSSe film on DSSCs performances was discussed in depth. The thermogravimetric analysis, phase morphology, conductivity, and electrochemical characteristics of CZTSSe films were performed. It is found that the rapid heating process is beneficial to the formation of well crystalline film with large grains. As the porosity and grain boundaries in the bulk film are dramatically reduced with the enhanced crystallization, the charge transport process is gradually improved. Using cyclic voltammogram and electrochemical impedance spectroscopy measurements, we propose that the accelerating charge transport is of great importance to the photovoltaic performances of DSSCs due to their superior electrocatalytic activities. As the highest cell efficiency was achieved, well crystalline CZTSSe is an efficient CE catalytic material. PMID:25382857

Chen, Hongli; Kou, Dongxing; Chang, Zhixian; Zhou, Wenhui; Zhou, Zhengji; Wu, Sixin

2014-12-10

170

Continuously tunable energy transfer laser operation in four-dye mixture systems  

NASA Astrophysics Data System (ADS)

Theoretical as well as experimental investigation of the energy transfer dye laser (ETDL) operation has been performed, aimed at development of a dye laser which covers a wide wavelength range without exchanging a dye mixture. The following two dye mixtures are shown to be very effective: Rhodamine 6(R6G)-Safrain T(ST)-Cresyl Violet (CV)-Nile Blue(NB) and Coumarin 1 (C1)-Acriflavine(A)-Uranine(U)-R6G. Their desirable dye concentrations are derived and the tuning characteristics are measured. Continuous tuning was achieved over 130 nm in either case, and hence almost the entire visible range is covered with these two ETDL's.

Muto, S.; Ito, C.; Inaba, H.

1983-11-01

171

Hevea brasiliensis cell suspension peroxidase: purification, characterization and application for dye decolorization  

PubMed Central

Peroxidases are oxidoreductase enzymes produced by most organisms. In this study, a peroxidase was purified from Hevea brasiliensis cell suspension by using anion exchange chromatography (DEAE-Sepharose), affinity chromatography (Con A-agarose) and preparative SDS-PAGE. The obtained enzyme appeared as a single band on SDS-PAGE with molecular mass of 70 kDa. Surprisingly, this purified peroxidase also had polyphenol oxidase activity. However, the biochemical characteristics were only studied in term of peroxidase because similar experiments in term of polyphenol oxidase have been reported in our pervious publication. The optimal pH of the purified peroxidase was 5.0 and its activity was retained at pH values between 5.0–10.0. The enzyme was heat stable over a wide range of temperatures (0–60°C), and less than 50% of its activity was lost at 70°C after incubation for 30 min. The enzyme was completely inhibited by ?-mercaptoethanol and strongly inhibited by NaN3; in addition, its properties indicated that it was a heme containing glycoprotein. This peroxidase could decolorize many dyes; aniline blue, bromocresol purple, brilliant green, crystal violet, fuchsin, malachite green, methyl green, methyl violet and water blue. The stability against high temperature and extreme pH supported that the enzyme could be a potential peroxidase source for special industrial applications. PMID:23402438

2013-01-01

172

Hevea brasiliensis cell suspension peroxidase: purification, characterization and application for dye decolorization.  

PubMed

Peroxidases are oxidoreductase enzymes produced by most organisms. In this study, a peroxidase was purified from Hevea brasiliensis cell suspension by using anion exchange chromatography (DEAE-Sepharose), affinity chromatography (Con A-agarose) and preparative SDS-PAGE. The obtained enzyme appeared as a single band on SDS-PAGE with molecular mass of 70 kDa. Surprisingly, this purified peroxidase also had polyphenol oxidase activity. However, the biochemical characteristics were only studied in term of peroxidase because similar experiments in term of polyphenol oxidase have been reported in our pervious publication. The optimal pH of the purified peroxidase was 5.0 and its activity was retained at pH values between 5.0-10.0. The enzyme was heat stable over a wide range of temperatures (0-60°C), and less than 50% of its activity was lost at 70°C after incubation for 30 min. The enzyme was completely inhibited by ?-mercaptoethanol and strongly inhibited by NaN3; in addition, its properties indicated that it was a heme containing glycoprotein. This peroxidase could decolorize many dyes; aniline blue, bromocresol purple, brilliant green, crystal violet, fuchsin, malachite green, methyl green, methyl violet and water blue. The stability against high temperature and extreme pH supported that the enzyme could be a potential peroxidase source for special industrial applications. PMID:23402438

Chanwun, Thitikorn; Muhamad, Nisaporn; Chirapongsatonkul, Nion; Churngchow, Nunta

2013-01-01

173

Size-controlled anatase titania single crystals with octahedron-like morphology for dye-sensitized solar cells.  

PubMed

A simple hydrothermal method with titanium tetraisopropoxide (TTIP) as a precursor and triethanolamine (TEOA) as a chelating agent enabled growth in the presence of a base (diethylamine, DEA) of anatase titania nanocrystals (HD1-HD5) of controlled size. DEA played a key role to expedite this growth, for which a biphasic crystal growth mechanism is proposed. The produced single crystals of titania show octahedron-like morphology with sizes in a broad range of 30-400 nm; a typical, extra large, octahedral single crystal (HD5) of length 410 nm and width 260 nm was obtained after repeating a sequential hydrothermal treatment using HD3 and then HD4 as a seed crystal. The nanocrystals of size ~30 nm (HD1) and ~300 nm (HD5) served as active layer and scattering layer, respectively, to fabricate N719-sensitized solar cells. These HD devices showed greater V(OC) than devices of conventional nanoparticle (NP) type; the overall device performance of HD attained an efficiency of 10.2% power conversion at a total film thickness of 28 ?m, which is superior to that of a NP-based reference device (? = 9.6%) optimized at a total film thickness of 18-20 ?m. According to results obtained from transient photoelectric and charge extraction measurements, this superior performance of HD devices relative to their NP counterparts is due to the more rapid electron transport and greater TiO(2) potential. PMID:23116194

Shiu, Jia-Wei; Lan, Chi-Ming; Chang, Yu-Cheng; Wu, Hui-Ping; Huang, Wei-Kai; Diau, Eric Wei-Guang

2012-12-21

174

The nonlinear refraction sign turned to reverse by intercalating cresyl violent dye into layered titanate nanosheets  

NASA Astrophysics Data System (ADS)

Solid-state dye-doped materials are an attractive alternative to conventional liquid dye solution. In this study, the spectral characteristics of dye cresyl violet before and after intercalating into layered titanate nanosheets and forming a nanohybrid thin film were investigated by measuring absorption and fluorescence spectra. In addition, their nonlinear optical properties were studied using single beam z-scan technique under irradiation of low power continuous wave (CW) produced by DPSS laser with a wavelength of 532 nm. The nonlinear studying results reveal that the dye cresyl violet in solution has a negative nonlinear refractive index, but it reverses to positive after the dye is intercalated into layered titanate nanosheets with a negative nonlinear refractive index forming CV/HTO nanohybrid thin film. This method can provide a way to turn to reverse nonlinear refraction sign of the materials.

Dou, Chunsheng; Wen, Puhong; Kong, Xingang; Nakanishi, Shunsuke; Feng, Qi

2011-02-01

175

Blue/red linear dichroic emission from a highly anisotropic crystal of triarylmethane dye conjugated with phenoxo-zinc complexes.  

PubMed

We have developed a novel triphenylmethane-based hexanuclear zinc complex that exhibits peculiar photochemical and photophysical properties. Upon UV irradiation, the compound turned from colorless to reddish purple, while the color of emission turned from blue to red. The color change was attributed to an oxidation of the ligand part. It was suggested that an intramolecular energy-transfer mechanism operates to give rise to the red emission. The UV treatment of a single crystal results in simultaneous emission of orthogonally polarized blue and red light. This color switching, namely linear dichroic emission was so distinct that one can recognize with by sight through optical microscope. The columnar arrangement of molecules in the crystal clearly accounts for the observed polarization of the emission. PMID:21243678

Houjou, Hirohiko; Takezawa, Shunpei; Oyamada, Issei; Matsumura, Kazunari; Seino, Hidetake; Yoshikawa, Isao; Mizobe, Yasushi; Araki, Koji

2011-01-24

176

Bactericidal installation using combined microwave and ultra-violet radiation  

Microsoft Academic Search

Summary form only given. The applications of independent microwave and ultra-violet radiation and ozone treatment for erasure of microbe flora are known. The results of the development of a combined microwave and ultra-violet irradiation and ozone treatment installation of a new type are presented. In this installation ultra-violet radiation is generated by electrodeless lamp with microwave excitation of electrodeless discharge.

A. Bezlepkin; V. Perevodchikov; E. Shlifer

2000-01-01

177

Orientation and electronic structure of ion exchanged dye molecules on mica: An X-ray absorption study  

SciTech Connect

Dye molecules are frequently used to determine the specific surface area and the ion exchange capacity of high-surface-area materials such as mica. The organic molecules are often considered to be planar and to adsorb in a flat orientation. In the present study the authors have investigated the orientation and electronic structure of crystal violet (CV) and malachite green (MG) on muscovite mica, prepared by immersing the substrates for extended periods into aqueous solutions of the dyes of various concentrations. The K{sup +} ions of the mica surface are replaced by the organic cations via ion exchange. X-ray photoelectron spectroscopy reveals that only one amino group is involved in the interaction of CV and MG with the muscovite surface, i.e., certain resonance structures are abolished upon adsorption. With near edge X-ray absorption fine structure spectroscopy a significant tilt angle with respect to the surface was found for all investigated species. A flat orientation, as has often been proposed before, can effectively be ruled out. Hence, results are in marked contrast to the often quoted orientation and suggest that the specific surface areas determined with dyes may, in general, be overestimated.

Fischer, D.; Caseri, W.R.; Haehner, G. [ETH Zuerich (Switzerland)] [ETH Zuerich (Switzerland)

1998-02-15

178

Influence of hole injection layer and work function of cathode on the performance of light-emitting liquid crystal cells with fluorescent dye-doped nematic liquid crystal  

NASA Astrophysics Data System (ADS)

We investigated the properties of rubrene-doped nematic-liquid-crystal cells to help determine the appropriate structure and material of electrodes for inducing light emission. In particular, we addressed the influence of the insertion of a hole injection layer (HIL) and the work function of the cathode on device performance. As a result, the employment of a HIL and a lower-work-function material was revealed to be effective in obtaining higher luminance and external quantum efficiency. We concluded that this improvement is caused by the facilitated carrier injection on the HIL and cathode surface, as is true for common organic light-emitting diodes.

Honma, Michinori; Horiuchi, Takao; Watanabe, Kyoko; Nose, Toshiaki

2014-11-01

179

Light-scattering determination of visco-elastic and electro-optic parameters of azo and anthraquinone dye-doped liquid crystal molecules and consistent neural network empirical physical formula construction for scattering intensities  

NASA Astrophysics Data System (ADS)

In this paper, we achieved two aims. Firstly, laser light-scattering intensities in methyl red (MR) azo and disperse red (DR) anthraquinone dye-doped nematic liquid crystal (NLC) molecules were measured versus scattering angle and applied bias voltage. The following three NLC molecular structure parameters were determined: the visco-elastic constant ratios K11/ K22 and K33/ K22 by data-regression and Freedericksz voltages from the graphs drawn. All these NLC parameters were found to be dependent on the kind of the dye used. As the second aim, by nonlinear universal function approximator layered feedforward neural network (LFNN), we constructed explicitform of empirical physical formulas (EPFs) for theoretically unknown nonlinear azo and anthraquinone dye-doped NLC scattering intensity functions. Excellent LFNN test set (i.e. yet-to-be measured experimental data) predictions prove that the constructed LFNN-EPFs estimate unknown intensity functions consistently. The LFNN-EPFs, too, confirmed the dependency on the kind of dye used. In conclusion, physical laws embedded in the scattering data can be consistently extracted by LFNN. One significant potential application in molecular nonlinear optics domain is that these LFNN-EPFs, by various mathematical tools such as differentiation, integration, and minimization, can be used to obtain further NLC scattering intensity knowledge related molecular structural parameters. Such knowledge in turn may prove useful in developing new optical materials.

Yildiz, Nihat; Polat, Ömer; San, Sait Eren; Kaya, Nihan

2011-04-01

180

Fluorescence enhancement of dyes embedded in nanoparticles of Lu, Eu, Al, and Sc diketonates of different composition and concentration  

NASA Astrophysics Data System (ADS)

We have studied the effect of central ions (Lu(III), Eu(III), Sc(III), and Al(III)), organic ligands (2-naphthoyltrifluoroacetone (NTA) and p-phenylbenzoyltrifluoroacetone (PhBTA)), and their concentration in a water-alcohol solution on the fluorescence of ?-diketonate complexes formed and nanoparticles (NPs) generated by the self-assembly of these complexes. The fluorescence quenching of ligands of the complexes of nanoparticles because of the introduction of molecules of dyes, such as Nile Blue (NB), Lissamine Rhodamine RB-200 (RB), and Crystal Violet (CV), in these nanoparticles is investigated, and the NP-sensitization of the fluorescence of these dyes is explored. The dependence of the intensity of the NP-sensitized fluorescence of NB on its concentration in nanoparticles consisting of complexes that differ in composition and concentration is studied. By analyzing this dependence for the nanoparticles consisting of Sc(NTA)3, the size of the studied nanoparticles is evaluated. It is shown that the nature of this dependence is determined by a competition of two processes: the migration of the excitation energy over complexes to dyes and the migration of the excitation energy of dyes to impurities or dimer of dyes. The size of nanoparticles is compared to the estimated values of the exciton diffusion length and the critical radius of energy transfer from complexes to NB. An energy transfer of close to 100% from the nanoparticles formed of 10 ?M of Sc(NTA)3 to 50 nM of NB molecules embedded therein is observed. The introduction of NB molecules into nanoparticles leads to a 200-fold increase in fluorescence intensity compared to their direct excitation in solution.

Mironov, L. Yu.; Sveshnikova, E. B.; Ermolaev, V. L.

2014-12-01

181

Probing and fluorescence enhanc with single gold nanorods  

E-print Network

antenna and can enhance fluorescence of a weak dye (crystal violet) by 1000-fold. The enhancement fac antenna and can enhance fluorescence of a weak dye (crystal violet) fold. The enhancement factor strongly is an efficient antenna and can enhance fluorescence of a weak dye (crystal violet) tor strongly depends

Shyamasundar, R.K.

182

Laser Oscillation of Energy Transfer Solid-State Dye Laser with a Thin-Film Ring Resonator  

NASA Astrophysics Data System (ADS)

We fabricated an energy transfer solid-state dye laser with a thin-film ring resonator. We combined several organic dyes, such as stilbene 3, coumarin 153, rhodamine B, and cresyl violet. The mixed dyes were embedded into the xerogel thin film by the sol-gel method. We pumped the dye molecules with a pulsed Nd:YAG laser third-harmonic generation (THG). Using the mixed-dye doped thin-film ring resonator, we obtained laser oscillation at four different wavelengths with one pumping source.

Fukuda, Makoto; Mito, Keiichi

2000-06-01

183

Single-molecule Fluorescence Spectroelectrochemistry of Cresyl Violet  

SciTech Connect

We coupled scanning fluorescence microscopy with a potentiostat via a three-electrode electrochemical cell to enable single-molecule fluorescence spectroelectrochemistry of cresyl violet in aqueous solution, where the single-molecule fluorescence intensity of cresyl violet is modulated synchronously with the cyclic voltammetric potential scanning.

Lei, Chenghong; Hu, Dehong; Ackerman, Eric J.

2008-11-21

184

Purification and characterization of a novel laccase from Coprinus cinereus and decolorization of different chemically dyes.  

PubMed

Laccase is a blue copper oxidase with multiple copper ions and widely distributed in higher plant and fungi. To date, numerous fungal laccases have been reported by many researchers. In present work, a new laccase gene, named CcLCC5I, from Coprinus cinereus was synthesized chemically according to the yeast bias codon and integrated into Pichia pastoris GS115 genome by electroporation. SDS-PAGE analysis showed that the recombinant laccase has a molecular mass of approximately 56.8 kDa. Its biochemical properties was carried out using substrate 2-2(')-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS). It was showed that the optimum pH and temperature of the laccase is 3.0 and 55 °C, respectively. Except for copper ions, most metal ions inhibited the laccase activity at a high concentration about 10 mM. Sodium sulfite can also highly inhibit laccase activity whereas EDTA had no inhibitory effect on the laccase activity. The CcLCC5I have high ability to decolor not only azo but also aryl methane dyes. The recombinant laccase decolored 44.6 % orange G, 54.8 % Crystal Violet, and 87.2 % Malachite green at about 2.6 h. The novel laccase may be a good candidate for breeding engineering strains used in the treatment of industrial effluent containing azo and aryl methane dyes. PMID:23073779

Lin, Yaqiu; Zhang, Zhen; Tian, Yongsheng; Zhao, Wei; Zhu, Bo; Xu, Zhisheng; Peng, Rihe; Yao, Quanhong

2013-02-01

185

75 FR 14468 - Carbazole Violet Pigment 23 From China and India  

Federal Register 2010, 2011, 2012, 2013, 2014

...Carbazole Violet Pigment 23 From China and India AGENCY: United States International Trade...order on carbazole violet pigment 23 from India and the antidumping duty orders on carbazole violet pigment 23 from China and...

2010-03-25

186

Electronic excitation transfer and lasing characteristics of mixed dye solutions under conditions of inhomogeneous broadening of their molecular spectra  

NASA Astrophysics Data System (ADS)

The effect of excitation energy transfer from rhodamine 6G (donor) to cresyl violet (acceptor) during lasing in their binary solutions under conditions of the inhomogeneous broadening of the electronic spectra of both components was investigated. The inhomogeneous spectral broadening was found to increase the lasing power of the acceptor dye. The lasing power of cresyl violet in a mixed solution increased both as a result of nonradiative energy transfer (about 20%) and by a radiative mechanism (about 80%).

Akimov, A. I.; Levshin, L. V.; Saletskii, A. M.; Iuzhakov, V. I.

1981-11-01

187

Study of photocatalytic activity of ZnS quantum dots as efficient nanoparticles for removal of methyl violet: Effect of ferric ion doping  

NASA Astrophysics Data System (ADS)

Zinc sulfide quantum dots (QDs), as pure and doped with Fe3+, were prepared for photodecolorization of methyl violet (MV), as a model dye, under UV light irradiation. The syntheses of QDs were carried out using a simple chemical co-precipitation method. The prepared samples were characterized by various techniques including X-ray diffraction, transmission electron microscopy, UV-Vis spectrophotometry and flame atomic absorption spectroscopy. The influences of operational parameters on the decolorization of MV such as dopant content, pH, dosage of nanophotocatalyst, UV irradiation time and initial dye concentration were studied. The results showed that the QDs presented high efficiency for MV decolorization, and doping of ZnS QDs with Fe3+ enhanced the efficiency and rate of dye removal. Finally, the reproducibility and kinetic model of the dye degradation were discussed.

Shamsipur, Mojtaba; Rajabi, Hamid Reza

2014-03-01

188

Study of photocatalytic activity of ZnS quantum dots as efficient nanoparticles for removal of methyl violet: effect of ferric ion doping.  

PubMed

Zinc sulfide quantum dots (QDs), as pure and doped with Fe(3+), were prepared for photodecolorization of methyl violet (MV), as a model dye, under UV light irradiation. The syntheses of QDs were carried out using a simple chemical co-precipitation method. The prepared samples were characterized by various techniques including X-ray diffraction, transmission electron microscopy, UV-Vis spectrophotometry and flame atomic absorption spectroscopy. The influences of operational parameters on the decolorization of MV such as dopant content, pH, dosage of nanophotocatalyst, UV irradiation time and initial dye concentration were studied. The results showed that the QDs presented high efficiency for MV decolorization, and doping of ZnS QDs with Fe(3+) enhanced the efficiency and rate of dye removal. Finally, the reproducibility and kinetic model of the dye degradation were discussed. PMID:24316540

Shamsipur, Mojtaba; Rajabi, Hamid Reza

2014-03-25

189

Determination of textile dyes in organs of Oncorhynchus mykiss W. after in vitro exposure  

Microsoft Academic Search

The quantitative determination in organs of Oncorhynchus mykiss W. of a premetallized dye (C.I. Acid Violet 66) and the azoic base (C.I. Acid Red 217), used in wool dyeing, is studied in this paper. UV-VIS Spectrophotometry was used for the chromatic quantification and atomic absorption spectrophotometry for the detection of the metal. The method described here is as satisfactory for

M. C. Riva; R. Flos; M. Crespi; M. Pepió

1992-01-01

190

The Fenton Chemistry and Its Combination with Coagulation for Treatment of Dye Solutions  

Microsoft Academic Search

Aqueous solutions of Acid Blue 74, Acid Orange 10, and Acid Violet 19 were subjected to Fenton\\/Fenton?like oxidation and its combination with lime coagulation. The analysis indicated no dependence of chemical oxidation efficacy on dye concentration in the range of 0.1–1 g L. Complete or nearly complete (higher than 95%) color removal of all treated samples was observed. Dye:H2O2 weight ratio of

Niina Kulik; Yekaterina Panova; Marina Trapido

2007-01-01

191

Crystals  

NSDL National Science Digital Library

In this earth science/math/art activity, learners use simple ingredients to grow crystals and examine the repeating geometric shapes and patterns. Learners compare the growth of crystals from four types of crystal-starters (table salt, Borax, sand, and Epsom salt) to see which starter grows the most crystals in 14 days. Learners report their results online and find out what other learners discovered. Afterward, learners can use the crystals they grew to create works of art.

Lawrence Hall of Science

2009-01-01

192

``Fast'' amplifying optical Kerr gate using stimulated emission of organic non-linear dyes  

NASA Astrophysics Data System (ADS)

We describe a "fast" optical Kerr gate (OKG) which can act at the same time as light amplifier. As a Kerr medium we used different laser dyes (Cresyl violet, Nile blue, Rhodamine 640). The most efficient at available wavelengths (595 nm and 297 nm) was Cresyl violet dissolved in methanol. With a classical OKG arrangement we obtained a maximum transmission of 4000% at 650 nm (strong amplification of the tramsmitted signal), this wavelength corresponding to a gain maximum of Cresyl violet. The opening time of the OKG was 15 ps limited by the reorientation time of the dye molecule in methanol solvent. With a special OKG arrangement based on the use of two delayed opening pulses, we obtained 240% transmission at the same wavelength with an opening time of 2.5 ps. Possible improvements of the method are described.

Jonusauskas, G.; Oberlé, J.; Abraham, E.; Rullière, C.

1997-02-01

193

Enhanced biodegradation of Reactive Violet 5R manufacturing wastewater using down flow fixed film bioreactor.  

PubMed

The present study emphasizes on the development of bioprocess for biodegradation and bioremediation of Reactive Violet 5R (RV5) manufacturing industry's wastewater in laboratory scale indigenously designed down flow fixed film bioreactor (DFFR). Process was investigated in DFFR, packed with furnace charcoal as a support material. During the batch and continuous operation of DFFR more than 95% degradation, 88% COD reduction and 99% copper remediation was obtained in less than 8h of contact time. Continuous mode treatment gave degradation of more than 2500mg dye in only 1h of contact time. Addition of 0.25% peptone enhanced biodegradation rate more than three-fold. The biologically treated wastewater was found to stimulate the growth of selected soil bacteria. Degradation of major components of the wastewater was confirmed by HPTLC. DFFR was operated successfully for 750d continuously, during which 716 cycles of batch treatment were operated. PMID:20638273

Sheth, Niraj; Dave, Shailesh

2010-11-01

194

Metallo-hydrazone complexes immobilized in zeolite Y: Synthesis, identification and acid violet-1 degradation  

NASA Astrophysics Data System (ADS)

Copper(II), cobalt(II) and nickel(II) complexes of hydrazone ligand (SAPH) derived from salicylaldehyde and phenylhydrazine have been encapsulated in zeolite-Y super cages via ship-in-a-bottle synthesis. Detailed characterization of the intrazeolitic complexes were performed by elemental analysis, spectral (FT-IR, UV-Vis.) studies, magnetic measurements and X-ray diffraction. Furthers, surface texture and thermal analysis (TG, DTG, DTA) have provided further evidence for successful immobilization of the metal complexes inside zeolite Y. Investigation of the stereochemistry of these incorporated chelates pointed out that, SAPH ligand is capable to coordinate with the central metal through the (C dbnd N), phenolic (OH) and (NH) groups forming polynuclear structures. The involvement of zeolite oxygen in coordination was postulated in the hybrid materials. The intrazeolitic copper, cobalt and nickel-SAPH complexes have distorted tetrahedral, octahedral and square-pyramidal configurations, respectively. The zeolite encapsulated complexes are thermally stable up to 800 °C except Cu(II) sample which is thermally stable up to midpoint 428 °C. The assessment of the catalytic activity was performed by the use of the photo-degradation of acid violet-1 dye as a probe reaction in presence of H 2O 2 as an oxidant. Decolorization of acid violet-1 dye was examined under the same conditions whereas the unpromoted zeolite and Cu II, Co II, Ni II-hydrazone complexes supported on zeolite showed 13% and 76%, 53%, 43% color removal, respectively. The results revealed that, the zeolite encapsulated Cu(II) complex generally exhibited better catalytic efficiency (76%) compared with other investigated zeolite encapsulated metal-hydrazone samples.

Ahmed, Ayman H.; Thabet, M. S.

2011-12-01

195

A comparative study on the properties, mechanisms and process designs for the adsorption of non-ionic or anionic dyes onto cationic-polymer\\/bentonite  

Microsoft Academic Search

The adsorption properties and mechanisms of a cationic-polymer\\/bentonite complex (EPI-DMA\\/bentonite), prepared from polyepicholorohydrin-dimethylamine and bentonite, for non-ionic dyes (Disperse Blue SBL and Vat Scarlet R) and anionic dyes (Reactive Violet K-3R and Acid Dark Blue 2G) were investigated in this study. The solution pH, presence of salt and surfactant can significantly affect the dye removal efficiency. The equilibrium data were

Qian Li; Qin-Yan Yue; Hong-Jian Sun; Yuan Su; Bao-Yu Gao

2010-01-01

196

Picosecond dynamics of cresyl violet H-aggregates adsorbed on SiO2 and SnO2 nanocrystallites  

NASA Astrophysics Data System (ADS)

The H-aggregates of cresyl violet dye which are formed on the negatively charged SiO2 and SnO2 nanocrystallites, exhibit relatively short-lived excitonic singlet state with a lifetime of about 35 ps. The difference absorption maximum (?max=470 nm) is blue shifted compared to the corresponding singlet excited state of monomer (?max=515 nm). Time-resolved transient absorption measurements show that these dye aggregates are capable of injecting electrons from the triplet excited state into SnO2 nanocrystallites. The rate constant for heterogeneous electron transfer as measured from the formation of cation radical and electron trapping in SnO2 nanocrystallites was 2.0×108 s-1.

Liu, Di; Kamat, Prashant V.

1996-07-01

197

Venus in Violet and Near Infrared Light  

NASA Technical Reports Server (NTRS)

These images of the Venus clouds were taken by Galileo's Solid State Imaging System February 13,1990, at a range of about 1 million miles. The smallest detail visible is about 20 miles. The two right images show Venus in violet light, the top one at a time six hours later than the bottom one. They show the state of the clouds near the top of Venus's cloud deck. A right to left motion of the cloud features is evident and is consistent with westward winds of about 230 mph. The two left images show Venus in near infrared light, at the same times as the two right images. Sunlight penetrates through the clouds more deeply at the near infrared wavelengths, allowing a view near the bottom of the cloud deck. The westward motion of the clouds is slower (about 150 mph) at the lower altitude. The clouds are composed of sulfuric acid droplets and occupy a range of altitudes from 30 to 45 miles. The images have been spatially filtered to bring out small scale details and de-emphasize global shading. The filtering has introduced artifacts (wiggly lines running north/south) that are faintly visible in the infrared image. The Galileo Project is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory; its mission is to study Jupiter and its satellites and magnetosphere after multiple gravity assist flybys at Venus and Earth.

1990-01-01

198

Determining the degradation efficiency and mechanisms of ethyl violet using HPLC-PDA-ESI-MS and GC-MS  

PubMed Central

Background The discharge of wastewater that contains high concentrations of reactive dyes is a well-known problem associated with dyestuff activities. In recent years, semiconductor photocatalysis has become more and more attractive and important since it has a great potential to contribute to such environmental problems. One of the most important aspects of environmental photocatalysis is in the selection of semiconductor materials like ZnO and TiO2, which are close to being two of the ideal photocatalysts in several respects. For example, they are relatively inexpensive, and they provide photo-generated holes with high oxidizing power due to their wide band gap energy. In this work, nanostructural ZnO film on the Zn foil of the Alkaline-Manganese Dioxide-Zinc Cell was fabricated to degrade EV dye. The major innovation of this paper is to obtain the degradation mechanism of ethyl violet dyes resulting from the HPLC-PDA-ESI-MS analyses. Results The fabrication of ZnO nanostructures on zinc foils with a simple solution-based corrosion strategy and the synthesis, characterization, application, and implication of Zn would be reported in this study. Other objectives of this research are to identify the reaction intermediates and to understand the detailed degradation mechanism of EV dye, as model compound of triphenylmethane dye, with active Zn metal, by HPLC-ESI-MS and GC-MS. Conclusions ZnO nanostructure/Zn-foils had an excellent potential for future applications on the photocatalytic degradation of the organic dye in the environmental remediation. The intermediates of the degradation process were separated and characterized by the HPLC-PDA-ESI-MS and GC-MS, and twenty-six intermediates were characterized in this study. Based on the variation of the amount of intermediates, possible degradation pathways for the decolorization of dyes are also proposed and discussed. PMID:22748361

2012-01-01

199

Iron complexed afterchrome dyes  

Microsoft Academic Search

The possibility of elimination of chromium in dye effluents during application of afterchrome dyes has been investigated. Eight commercially available azo mordant dyes were used in dyeing of wood fabric and aftertreated with iron (II) and iron (III) salts. Colour and lightfastness of received dyeings was compared with those obtained with the use of traditional chromium-aftertreated method. The structure of

Wojciech Czajkowski; Ma?gorzata Szymczyk

1998-01-01

200

Dye laser amplifier  

DOEpatents

An improved dye laser amplifier is disclosed. The efficiency of the dye laser amplifier is increased significantly by increasing the power of a dye beam as it passes from an input window to an output window within the dye chamber, while maintaining the intensity of the dye beam constant. 3 figs.

Moses, E.I.

1992-12-01

201

Genotoxicity studies on the removal of a direct textile dye by a fungal strain, in vivo, using micronucleus and RAPD-PCR techniques on male rats.  

PubMed

The genotoxicity of the azo dye 'Direct Violet' and the removal of this dye by Aspergillus niger strain at different conditions have been investigated in male rats. Two genotoxicity techniques, namely bone marrow micronucleus assay and RAPD fingerprinting pattern, were used in this study for the direct dye and its removal by the fungal strain. Sixty male rats were divided into six treatment groups including a control group and other groups which were exposed for 2 or 8 weeks to Direct Violet dye, Direct Violet dye treated with A. niger at pH 2 or pH 9 or without agitation and acrylamide (30 mg/kg b.w.). A potent dose-dependent response was observed following oral gavage of the dye up to 1000 mg kg(-1), after which significant toxicity to the erythroid compartment was observed. Acrylamide and Direct Violet treatments increased the number of micronucleated polychromatic erythrocytes (MnPCEs) with respect to the controls. This increase was statistically significant in the two time intervals (2 and 8 weeks treatment, P < 0.0001). Fungi treatments at pH 2 and without agitation were able to reduce the number of MnPCEs induced by Direct Violet administration in all duration groups. Fungi treatment at pH 9 was only able to inhibit the genotoxicity of Direct Violet after 8 weeks treatment. The RAPD fingerprinting pattern indicated that most DNA of the samples treated with dye alone or acrylamide revealed polymorphic bands including the appearance and disappearance of the bands, which did not appear in the DNA samples of normal or fungi protected rats. The implications of these findings for the health and safety of occupationally exposed workers are discussed. PMID:17879240

El-Rahim, Wafaa M Abd; Khalil, Wagdy K B; Eshak, Mariam G

2008-05-01

202

Dye Sensitized Tandem Photovoltaic Cells  

SciTech Connect

This work provided a new way to look at photoelectrochemical cells and their performance. Although thought of as low efficiency, a the internal efficiency of a 9% global efficiency dye sensitized solar cell is approximately equal to an 18% efficient silicon cell when each is compared to their useful spectral range. Other work undertaken with this contract also reported the first growth oriented titania and perovskite columns on a transparent conducting oxide. Other work has shown than significant performance enhancement in the performance of dye sensitized solar cells can be obtained through the use of coupling inverse opal photonic crystals to the nanocrystalline dye sensitized solar cell. Lastly, a quick efficient method was developed to bond titanium foils to transparent conducting oxide substrates for anodization.

Barber, Greg D.

2009-12-21

203

Sensitization of nanostructured TiO2 by electrostatic coupling of ionic dyes to ionic absorbates.  

PubMed

It is shown that an ionic dye Y can be electrostatically bonded to an ionic molecule X of opposite charge anchored to a TiO2 surface via suitable ligands. Dye-sensitized solid-state photovoltaic cells of the configuration n-TiO2/X-Y/p-CuSCN were constructed with X = trihydroxybenzoic acid or mercurochrome and Y = methyl violet. Cells of this configuration were found to be more efficient and delivered higher short-circuit photocurrents and open-circuit photovoltages compared to the cells based only on methyl violet or mercurochrome. It is suggested that this technique would be a means of extending the spectral response of dye-sensitized photovoltaic devices. The formation of a wider barrier by coupling of anionic and cationic species also improves the cell performance by suppression of recombination. PMID:15984273

Pitigala, P K D D P; Seneviratne, M K I; Perera, V P S; Tennakone, K

2004-06-01

204

Fully resonant CARS of cresyl violet in polyacrylic acid polymer films  

NASA Astrophysics Data System (ADS)

Multi-resonant CARS data for ground and excited electronic state resonances (593.585 cm -1) of cresyl violet perchlorate in polyacrylic acid are reported. The intensity of the excited state resonance (585 cm -1) depends on the location of the ? 1-field (? as = 2? 1 - ? 2) within the severely inhomogeneously broadened absorption profile of the dye. Non-photochemical hole burning is used to determine the vibronic transitions which contribute to the absorption profile. It is argued that the linear electron-phonon interaction is an important mechanism for producing an egalitarian distribution of excited dye sites with a population sufficiently high to permit observation of the excited state resonance. A marked non-photochemical hole burning effect on the intensities of the CARS resonances is used for the assignment of 585 cm -1 as an excited state resonance. The absence of line narrowing in the CARS and CSRS spectra is reported and discussed. Finally, a novel narrowing of the 593 cm -1 ground state resonance with increasing temperature is reported and shown to occur only for restricted values (frequency) of ? 1.

Chang, Ta-Chau; Small, Gerald J.

1985-11-01

205

A rapid and simple method for simultaneous determination of triphenylmethane dye residues in rainbow trouts by liquid chromatography-tandem mass spectrometry.  

PubMed

A rapid and simple LC-MS/MS method was developed and optimized for screening and confirmation of triphenylmethane dyes including malachite green (MG), leucomalachite green (LMG), crystal violet (CV), leucocrystal violet (LCV) and brilliant green (BG) in fish muscle with skin. Leucocrystal violet D6 (LCV-D6) and leucomalachite green-D5 (LMG D5) was used as internal standards. Sample preparation is a simple procedure based on solid-liquid extraction with acetonitrile containing 1% acetic acid, followed by centrifugation and evaporation of the supernatant. The residue was dissolved in acetonitrile with 0.1% acetic acid and centrifuged prior to LC-MS/MS analysis. Chromatographic separation of analytes was performed on an Inertsil ODS-4 C18 column with ammonium acetate buffer in acetonitrile gradient. The mass detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode via electrospray ionization (ESI+). The developed method was validated according to the criteria set in Commission Decision 2002/657/EC. The decision limit (CC?) was 0.43, 0.24, 0.33, 0.28 and 0.17?gkg(-1) for MG, LMG, CV, LCV and BG respectively. The detection capability (CC?) values obtained were 0.56, 0.31, 0.43, 0.37 and 0.22?gkg(-1), respectively. The precision of the method, expressed as relative standard deviation (RSD) values for the within-day and inter-day laboratory reproducibility, for MG, LMG, CV, LCV and BG at the four levels of fortification (0.3, 0.5, 1, and 2?gkg(-1)), was less than 16 and 19% respectively. Accuracy of the method was confirmed by successful participation of a proficiency test organized by FAPAS. The method has been used for the analysis of 208 fish samples of which seven samples were found to be non-compliant containing low residues of LMG and LCV. PMID:24866565

Kaplan, Muammer; Olgun, Elmas O; Karaoglu, Oznur

2014-07-01

206

Tunable blue–violet Cr3+:LiCAF + BiBO compact laser  

NASA Astrophysics Data System (ADS)

We present a compact continuous wave (CW) external-cavity tunable Cr3+:LiCaAlF6 (Cr:LiCAF) laser which is intracavity frequency doubled using a BiB3O6 (BiBO) nonlinear crystal to obtain tunable blue–violet radiation. The generated second harmonic (SH) can be tuned by means of either angular or temperature variation of the nonlinear crystal. We have obtained SH radiation between 390–415 nm and a maximum output power of 34 mW at 400 nm. Future improvements on the SH tuning range and output power are addressed in the text. Our results may be applied in the design of compact tunable composite external-cavity solid-state lasers.

Maestre, H.; Torregrosa, A. J.; Capmany, J.

2015-03-01

207

crystal  

NASA Astrophysics Data System (ADS)

A Nd3+:Na2La4(WO4)7 crystal with dimensions of ? 17 × 30 mm3 was grown by the Czochralski method. The thermal expansion coefficients of Nd3+:Na2La4(WO4)7 crystal are 1.32 × 10-5 K-1 along c-axis and 1.23 × 10-5 K-1 along a-axis, respectively. The spectroscopic characteristics of Nd3+:Na2La4(WO4)7 crystal were investigated. The Judd-Ofelt theory was applied to calculate the spectral parameters. The absorption cross sections at 805 nm are 2.17 × 10-20 cm2 with a full width at half maximum (FWHM) of 15 nm for ?-polarization, and 2.29 × 10-20 cm2 with a FWHM of 14 nm for ?-polarization. The emission cross sections are 3.19 × 10-20 cm2 for ?-polarization and 2.67 × 10-20 cm2 for ?-polarization at 1,064 nm. The fluorescence quantum efficiency is 67 %. The quasi-cw laser of Nd3+:Na2La4(WO4)7 crystal was performed. The maximum output power is 80 mW. The slope efficiency is 7.12 %. The results suggest Nd3+:Na2La4(WO4)7 crystal as a promising laser crystal fit for laser diode pumping.

Yu, Yi; Huang, Yisheng; Zhang, Lizhen; Lin, Zhoubin; Sun, Shijia; Wang, Guofu

2014-07-01

208

Dyes for Optical Recording  

Microsoft Academic Search

Dyes for optical recording systems such as laser optical recording systems, laser printing systems, cycolor and related systems, xerography and so on are reviewed. Infrared absorbing (IR) dyes are newly designed for laser optical recording systems such as DRAW and erasable type recording systems. The chemistry of IR dyes developed the new fields in dye chemistry. Many of functionalities in

Masaru Matsuoka

1993-01-01

209

21 CFR 74.2602 - D&C Violet No. 2.  

Code of Federal Regulations, 2010 CFR

...specifications. The color additive D&C Violet No. 2...restrictions. The color additive D&C Violet No. 2...consistent with good manufacturing practice. (c) Labeling...The label of the color additive shall conform to...

2010-04-01

210

21 CFR 74.2602 - D&C Violet No. 2.  

Code of Federal Regulations, 2013 CFR

...specifications. The color additive D&C Violet No. 2...restrictions. The color additive D&C Violet No. 2...consistent with good manufacturing practice. (c) Labeling...The label of the color additive shall conform to...

2013-04-01

211

21 CFR 74.2602 - D&C Violet No. 2.  

Code of Federal Regulations, 2011 CFR

...specifications. The color additive D&C Violet No. 2...restrictions. The color additive D&C Violet No. 2...consistent with good manufacturing practice. (c) Labeling...The label of the color additive shall conform to...

2011-04-01

212

21 CFR 74.2602 - D&C Violet No. 2.  

Code of Federal Regulations, 2014 CFR

...specifications. The color additive D&C Violet No. 2...restrictions. The color additive D&C Violet No. 2...consistent with good manufacturing practice. (c) Labeling...The label of the color additive shall conform to...

2014-04-01

213

21 CFR 74.2602 - D&C Violet No. 2.  

Code of Federal Regulations, 2012 CFR

...specifications. The color additive D&C Violet No. 2...restrictions. The color additive D&C Violet No. 2...consistent with good manufacturing practice. (c) Labeling...The label of the color additive shall conform to...

2012-04-01

214

MODIFICATION AND CHARACTERIZATION OF DRY MATERIAL FEEDER FOR DELIVERY OF RED AND VIOLET DYE MIXTURES  

EPA Science Inventory

Uniform delivery of dry material for stable concentrations of aerosols in inhalation exposure chambers is essential in inhalation experiments. his paper characterizes an AccuRate dry material feeder with modifications, for different helix sizes, actuation rates, nozzle types and ...

215

POLLINISATION DU TRFLE VIOLET DIPLOIDE (TRIFOLIUM PRATENSE L.)  

E-print Network

POLLINISATION DU TRÃ?FLE VIOLET DIPLOIDE (TRIFOLIUM PRATENSE L.) PAR LES APOIDES ET PARTICULIÃ?REMENT des diploiden Rotklees (Trifolium pratense L.) durch die Apoideen und besonders durch die Kreuzung der.A.P.F., 86600 Lusignan SUMMARY POLLINATION OF DIPLOID RED CLOVER (Trifolium pratense L.) BY APOIDEA

Boyer, Edmond

216

Nanorod-nanosheet hierarchically structured ZnO crystals on zinc foil as flexible photoanodes for dye-sensitized solar cells.  

PubMed

In this paper, ZnO nanorod-nanosheet hierarchical structures were fabricated using a facile method on zinc foil and used as flexible photoanodes in dye-sensitized solar cells (DSCs). Compared to nanorods (NRs) obtained by the dissolution-precipitation method, the nanorod-nanosheet (NR-NS) hierarchical structures obtained by a second-step homogeneous precipitation improved the performance of DSCs by increasing photocurrent density significantly. As a result, the power conversion efficiency of the devices based on such a NR-NS hierarchical structure reached up to 2.4% under 100 mW cm(-2) illumination condition. This represents an enhancement by 108% as compared to DSCs based on NR assembled nanoflowers, for which the efficiency was 1.1%. The enhancement of the photocurrent was due mainly to the much larger specific surface area and resulting dye-loading amount. The electron transport properties in this structure were also investigated by means of electrochemical impedance spectroscopy (EIS). Furthermore, the formation mechanism of the NR-NS hierarchical structures are discussed. PMID:23353672

Gao, Rui; Tian, Jianjun; Liang, Zhiqiang; Zhang, Qifeng; Wang, Liduo; Cao, Guozhong

2013-03-01

217

75 FR 33243 - Carbazole Violet Pigment 23 From India: Final Results of Countervailing Duty Administrative Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-839] Carbazole Violet Pigment 23 From India: Final Results of Countervailing Duty...order on carbazole violet pigment 23 from India for the period January 1, 2007, through...See Carbazole Violet Pigment 23 from India: Preliminary Results of...

2010-06-11

218

Diffusion controlled reactions: Fluorescence quenching of cationic dyes by charged quenchers  

NASA Astrophysics Data System (ADS)

Rate coefficients of diffusion-limited fast reactions of charged reactants are predicted to be time dependent or time independent in different theoretical approaches to solve the Debye-Smoluchowski equation. Different rate coefficient expressions are also predicted in different time domains. Fluorescence quenching experiments using two cationic dyes (rhodamine B and cresyl violet) and four efficient ionic quenchers (iron complexes) in aqueous solutions were carried out to verify the theoretical prediction. A detailed data analysis of the quenched fluorescence decay over a range of concentration of the quenchers supports the prediction that the ``long'' time rate coefficient is k(t)˜a+bt-1/2. Exact agreement with the theoretical predictions is not obtained in any of the fluorophore-quencher systems described in this work. Cresyl violet-ferrocyanide and cresyl violet-ferricyanide are two systems for which the experimental values of diffusion coefficient D and distance parameter RHN are justifiably close to theoretical expectation.

Periasamy, N.; Doraiswamy, S.; Maiya, G. B.; Venkataraman, B.

1988-02-01

219

Poly (Acrylamide-co-Acrylic Acid) Hydrogel Induced by Glow-Discharge Electrolysis Plasma and Its Adsorption Properties for Cationic Dyes  

NASA Astrophysics Data System (ADS)

In this paper, poly (acrylamide-co-acrylic acid) (P(AM-co-AA)) hydrogel was prepared in an aqueous solution by using glow-discharge electrolysis plasma (GDEP) induced copolymerization of acrylamide (AM) and acrylic acid (AA), in which N,N'-methylenebisacrylamide (MBA) was used as a crosslinker. A mechanism for the synthesis of P(AM-co-AA) hydrogel was proposed. To optimize the synthesis condition, the following parameters were examined in detail: the discharge voltage, discharge time, the content of the crosslinker, and the mass ratio of AM to AA. The results showed that the optimum pH range for cationic dyes removal was found to be 5.0-10.0. The P(AM-co-AA) hydrogel exhibits a very high adsorption potential and the experimental adsorption capacities for Crystal violet (CV) and Methylene blue (MB) were 2974.3 mg/g and 2303.6 mg/g, respectively. The adsorption process follows a pseudo-second-order kinetic model. In addition, the adsorption mechanism of P(AM-co-AA) hydrogel for cationic dyes was also discussed.

Yu, Jie; Yang, Gege; Pan, Yuanpei; Lu, Quanfang; Yang, Wu; Gao, Jinzhang

2014-08-01

220

High power CW dye laser emission around 888 nm M. Leduc and G. Trenec  

E-print Network

and the near IR using various classes of dyes and/or colour centres in crystals. CW laser emission near 900 nm has previously been reported in two cyanine dyes : HITC [1, 2] and IR 140 [3]. More recently colour355 High power CW dye laser emission around 888 nm M. Leduc and G. Trenec Laboratoire de

Paris-Sud XI, Université de

221

Achievement of a wide wavelength tuning range for lasing in the green and red spectral regions using new laser dyes  

NASA Astrophysics Data System (ADS)

The lasing characteristics of two new dyes related to the naphthalimide and benzantron classes were measured during pumping by second-harmonic ruby laser radiation. The tuning of the lasing wavelength was achieved in the range of about 100 nm (from 500 to 600 nm for naphthalimide and from 640 to 740 nm for benzantron). It is shown that the lasing energy of these compounds exceeds that of the widely used dyes coumarin 7 and uranin in the green region and cresyl violet in the red; moreover, their wavelength tuning range is substantially broader than that of conventional dyes.

Krymova, A. I.; Petukhov, V. A.

1986-03-01

222

crystal  

NASA Astrophysics Data System (ADS)

An eye-safe Raman laser is realized with BaTeMo2O9 (BTM) nonlinear crystal for the first time. By using a diode-end-pumped acousto-optically Q-switched Nd:YVO4 laser as the pumping source, the BTM crystal converts the fundamental laser at 1,342 nm to first-Stokes laser at 1,531 nm successfully. With an incident power of 10.8 W and a pulse repetition rate of 25 kHz, the average output power at 1,531 nm is obtained to be 0.83 W, corresponding to a diode-to-Stokes conversion efficiency of 7.7 %. The pulse width is 11 ns, and the peak power is 3.0 kW.

Bai, Fen; Wang, Qingpu; Tao, Xutang; Li, Ping; Zhang, Xingyu; Liu, Zhaojun; Shen, Hongbin; Lan, Weixia; Gao, Liang; Gao, Zeliang; Zhang, Junjie; Fang, Jiaxiong

2014-08-01

223

Decolorization of synthetic dyes by solid state cultures of Lentinula (Lentinus) edodes producing manganese peroxidase as the main ligninolytic enzyme.  

PubMed

The ability of the white-rot fungus Lentinula (Lentinus) edodes to decolorize several synthetic dyes was investigated using solid state cultures with corn cob as substrate. Cultures, containing amido black, congo red, trypan blue, methyl green, remazol brilliant blue R, methyl violet, ethyl violet and Poly R478 at 200 ppm, were completely decolorized after 18 days of incubation. Partial decolorization was observed in the cultures containing 200 ppm of brilliant cresyl blue and methylene blue. High manganese peroxidase activity (2600 U/g substrate), but very low lignin peroxidase (<10 U/g substrate) and laccase (<16 U/g substrate) activities were detected in the cultures. In vitro, the dye decolorization was markedly decreased by the absence of manganic ions and H2O2. These data suggest that manganese peroxidase appear to be the main responsible for the capability of L. edodes to decolorize synthetic dyes. PMID:15158501

Boer, Cinthia Gandolfi; Obici, Larissa; de Souza, Cristina Giatti Marques; Peralta, Rosane M

2004-09-01

224

Mercurochrome: a fluorescent and electron opaque dye.  

PubMed

Mercurochrome was applied to tissues and tissue sections in an attempt to examine structural components either in visible light, fluorescence or electron microscopy. Samples of bone marrow from rats were fixed in glutaraldehyde alone, embedded in Durcupan, and studied by using semi-thin and thin sections. After treatment with mercurochrome in acetone before embedding, the eosinophilic granules from leucocytes and chromatin masses showed electron opacity as well as a yellowish green fluorescence under excitation with violet-blue or blue light. An additional treatment of sections with an alkaline hydroalcoholic solution of the dye allowed to visualize these structures under bright-field illumination and to improve the contrast in the electron microscope. This method offers the possibility to examine specific cell components by using a compound which simultaneously possesses staining, fluorescence, and electron microscopic contrasting properties. PMID:6195509

Ferrer, J M; González Garrigues, M; Stockert, J C

1983-05-01

225

Photoconversion of DAPI following UV or violet excitation can cause DAPI to fluoresce with blue or cyan excitation.  

PubMed

4'-6-Diamidino-2-phenylindole is a fluorescent dye commonly used to visualize deoxyribonucleic acid or cell nuclei in fixed cell preparations, and is often used together with fluorescein or green fluorescent protein, which can be excited without exciting 4'-6-Diamidino-2-phenylindole. It is assumed that when using typical fluorescein or green fluorescent protein filter cubes, 4'-6-Diamidino-2-phenylindole will not be observed. In this paper, we show that following observation of 4'-6-Diamidino-2-phenylindole using UV or violet excitation, it may become sensitive to the blue/cyan excitation used in fluorescein/green fluorescent protein filter cubes. This has serious implications for the use of 4'-6-Diamidino-2-phenylindole together with widely used green fluorophores in double labelling experiments. PMID:22288651

Piterburg, M; Panet, H; Weiss, A

2012-04-01

226

Zeolite-dye micro lasers  

E-print Network

We present a new class of micro lasers based on nanoporous molecular sieve host-guest systems. Organic dye guest molecules of 1-Ethyl-4-(4-(p-Dimethylaminophenyl)-1,3-butadienyl)-pyridinium Perchlorat were inserted into the 0.73-nm-wide channel pores of a zeolite AlPO$_4$-5 host. The zeolitic micro crystal compounds where hydrothermally synthesized according to a particular host-guest chemical process. The dye molecules are found not only to be aligned along the host channel axis, but to be oriented as well. Single mode laser emission at 687 nm was obtained from a whispering gallery mode oscillating in a 8-$\\mu$m-diameter monolithic micro resonator, in which the field is confined by total internal reflection at the natural hexagonal boundaries inside the zeolitic microcrystals.

Vietze, U; Laeri, F; Ihlein, G; Schüth, F; Limburg, B; Abraham, M

1998-01-01

227

Laser dye stability  

Microsoft Academic Search

Lasing characteristics and bleaching of four Eastman Kodak ir dyes have been examined in dimethyl sulfoxide. These ir dyes\\u000a are shown to improve in performance in the absence of oxygen. Their photochemical stability was found to be comparable to\\u000a the quinolone laser dyes when exposed to flashlamp excitation. Photodecomposition of the ir dyes under lasing conditions was\\u000a found to vary

N. Fletcher

1980-01-01

228

Cyanine dyes in solid state organic heterojunction solar cells  

NASA Astrophysics Data System (ADS)

Today numerous cyanine dyes that are soluble in organic solvents are available, driven by more than a century of research and development of the photographic industry. Several properties specific to cyanine dyes suggest that this material class can be of interest for organic solar cell applications. The main absorption wavelength can be tuned from the ultra-violet to the near-infrared. The unparalleled high absorption coefficients allow using very thin films for harvesting the solar photons. Furthermore, cyanines are cationic polymethine dyes, offering the possibility to modify the materials by defining the counteranion. We here show specifically how counterions can be utilized to tune the bulk morphology when blended with fullerenes. We compare the performance of bilayer heterojunction and bulk heterojunction solar cells for two different dyes absorbing in the visible and the near-infrared. Light-induced Electron Spin Resonance (LESR) was used to study the charge transfers of light induced excitons between cyanine dyes and the archetype fullerene C60. LESR results show good correlation with the cell performance.

Heier, Jakob; Peng, Chuyao; Véron, Anna C.; Hany, Roland; Geiger, Thomas; Nüesch, Frank A.; Vismara, Marcus V. G.; Graeff, Carlos F. O.

2014-10-01

229

Dye Like A Natural  

NSDL National Science Digital Library

In this activity, learners stain fabrics--on purpose! Learners explore the art of natural dyeing by using dyes and substrates that are both derived from plant or animal sources as well as mordant solutions. Learners compare the color and effectiveness of different mordant/dye combinations on the different substrates.

Julie Yu

2010-01-01

230

Photoporation and cell transfection using a violet diode laser  

NASA Astrophysics Data System (ADS)

The introduction and subsequent expression of foreign DNA inside living mammalian cells (transfection) is achieved by photoporation with a violet diode laser. We direct a compact 405 nm laser diode source into an inverted optical microscope configuration and expose cells to 0.3 mW for 40 ms. The localized optical power density of ~1200 MW/m2 is six orders of magnitude lower than that used in femtosecond photoporation (~104 TW/m2). The beam perforates the cell plasma membrane to allow uptake of plasmid DNA containing an antibiotic resistant gene as well as the green fluorescent protein (GFP) gene. Successfully transfected cells then expand into clonal groups which are used to create stable cell lines. The use of the violet diode laser offers a new and simple poration technique compatible with standard microscopes and is the simplest method of laser-assisted cell poration reported to date.

Paterson, L.; Agate, B.; Comrie, M.; Ferguson, R.; Lake, T. K.; Morris, J. E.; Carruthers, A. E.; Brown, C. T. A.; Sibbett, W.; Bryant, P. E.; Gunn-Moore, F.; Riches, A. C.; Dholakia, Kishan

2005-01-01

231

Adsorption of Phenol and Basic Dye on Carbon Nanotubes\\/Carbon Fabric Composites from Aqueous Solution  

Microsoft Academic Search

The liquid-phase adsorption of phenol and dye (basic violet 10) onto carbon nanotube (CNT)-activated carbon fabric (ACF) composites, prepared by a catalytic chemical vapor deposition (CCVD) approach, has been investigated. The CCVD technique enables the decoration of CNTs on microscaled ACFs, creating a hierarchy CNT-ACF composite. The as-grown nanotubes were found to have a tortuous shape and to be several

Jung-Pin Wang; Hsi-Chi Yang; Chien-Te Hsieh

2010-01-01

232

Bioremediation of direct dyes in simulated textile effluents by a paramorphogenic form of Aspergillus oryzae.  

PubMed

Azo dyes are extensively used for coloring textiles, paper, food, leather, drinks, pharmaceutical products, cosmetics and inks. The textile industry consumes the largest amount of azo dyes, and it is estimated that approximately 10-15% of dyes used for coloring textiles may be lost in waste streams. Almost all azo dyes are synthetic and resist biodegradation, however, they can readily be reduced by a number of chemical and biological reducing systems. Biological treatment has advantages over physical and chemical methods due to lower costs and minimal environmental effect. This research focuses on the utilization of Aspergillus oryzae to remove some types of azo dyes from aqueous solutions. The fungus, physically induced in its paramorphogenic form (called 'pellets'), was used in the dye biosorption studies with both non-autoclaved and autoclaved hyphae, at different pH values. The goals were the removal of dyes by biosorption and the decrease of their toxicity. The dyes used were Direct Red 23 and Direct Violet 51. Their spectral stability (325-700 nm) was analyzed at different pH values (2.50, 4.50 and 6.50). The best biosorptive pH value and the toxicity limit, (which is given by the lethal concentration (LC(100)), were then determined. Each dye showed the same spectrum at different pH values. The best biosorptive pH was 2.50, for both non- autoclaved and autoclaved hyphae of A. oryzae. The toxicity level of the dyes was determined using the Trimmed Spearman-Karber Method, with Daphnia similis in all bioassays. The Direct Violet 51 (LC(100) 400 mg · mL(-1)) was found to be the most toxic dye, followed by the Direct Red 23 (LC(100) 900 mg · mL(-1)). The toxicity bioassays for each dye have shown that it is possible to decrease the toxicity level to zero by adding a small quantity of biomass from A. oryzae in its paramorphogenic form. The autoclaved biomass had a higher biosorptive capacity for the dye than the non-autoclaved biomass. The results show that bioremediation occurs with A. oryzae in its paramorphogenic form, and it can be used as a biosorptive substrate for treatment of industrial waste water containing azo dyes. PMID:22466598

Corso, C R; Almeida, E J R; Santos, G C; Morão, L G; Fabris, G S L; Mitter, E K

2012-01-01

233

A study of mode-locked argon ion-dye laser systems  

NASA Astrophysics Data System (ADS)

A new argon ion dye laser double mode locking cavity is presented that allows simultaneous pulse period variation in both laser pulse trains. The predicted number of pulses are analyzed and hence the period of pulses for different cavity length adjustments. A novel approach to creating synchronous picosecond pulse trains at two wavelengths is presented. The method uses a synchronously pumped argon ion laser to cause population inversion and lasing in a mixture of rhodamine 6G and cresyl violet dye. This synchronously pumped double mode locking is simpler to implement than other two wavelength methods. The pulses produced are superior to those generated in the widely used commercial synchronously pumped systems.

Selfridge, R. H.

1984-06-01

234

THE FLUORESCENCE EFFICIENCIES OF THE CN VIOLET BANDS IN COMETS  

SciTech Connect

We have carried out calculations of the fluorescent equilibrium of the CN molecule in the solar radiation field as a function of heliocentric radial velocity and distance. The detailed rotational line intensities of the CN violet 0-0 band have been recalculated for radial velocities between -60 and +60 km s{sup -1} and at 10 distances in steps of {radical}2 from 0.25 to 5.7 AU. Comparisons with observed CN violet 0-0 band profiles yield reasonable agreement and remaining discrepancies are well understood. Based on the derived equilibrium rotational level populations of the ground state, 1-1 band rotational line intensities were also calculated. Total band fluorescence efficiencies for the violet {Delta}{nu} = 0 sequence are tabulated for the above range of distances and velocities, permitting the interpolation to any given comet's observational circumstances. These fluorescence efficiencies, L/N, or 'g-factors', needed to reduce CN emission band fluxes to CN abundances, are also accessible via a Web-based service. The values at any heliocentric distance vary by about a factor of two with varying velocities, but the specific structure of this variation with velocity changes dramatically with distance.

Schleicher, David G., E-mail: dgs@lowell.ed [Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001 (United States)

2010-10-15

235

Tests and calibration on ultra violet imaging telescope (UVIT)  

NASA Astrophysics Data System (ADS)

Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of Far Ultra Violet (FUV; 130 - 180 nm), Near Ultra Violet (NUV; 200 - 300 nm) and Visible band (VIS; 320-550nm) imagers. ASTROSAT is a first multi wavelength mission of INDIA. UVIT will image the selected regions of the sky simultaneously in three channels & observe young stars, galaxies, bright UV Sources. FOV in each of the 3 channels is ~ 28 arc-minute. Targeted angular resolution in the resulting UV images is better than 1.8 arc-second (better than 2.0 arc-second for the visible channel). Two identical co-aligned telescopes (T1, T2) of Ritchey-Chretien configuration (Primary mirror of ~375 mm diameter) collect the celestial radiation and feed to the detector system via a selectable filter on a filter wheel mechanism; gratings are available in the filter wheels of FUV and NUV channels for slit-less low resolution spectroscopy. The detector system for each of the 3 channels is generically identical. One telescope images in the FUV channel, and other images in NUV and VIS channels. One time open-able mechanical cover on each telescope also works as Sun-shield after deployment. We will present the optical tests and calibrations done on the two telescopes. Results on vibrations test and thermo-vacuum tests on the engineering model will also be presented.

Kumar, Amit; Ghosh, S. K.; Kamath, P. U.; Postma, Joe; Kathiravan, S.; Mahesh, P. K.; Nagbhushana, S.; Navalgund, K. H.; Rajkumar, N.; Rao, M. N.; Sarma, K. S.; Sriram, S.; Stalin, C. S.; Tandon, S. N.

2012-09-01

236

Decolorization of Anthraquinonic Dyes from Textile Effluent Using Horseradish Peroxidase: Optimization and Kinetic Study  

PubMed Central

Two anthraquinonic dyes, C.I. Acid Blue 225 and C.I. Acid Violet 109, were used as models to explore the feasibility of using the horseradish peroxidase enzyme (HRP) in the practical decolorization of anthraquinonic dyes in wastewater. The influence of process parameters such as enzyme concentration, hydrogen peroxide concentration, temperature, dye concentration, and pH was examined. The pH and temperature activity profiles were similar for decolorization of both dyes. Under the optimal conditions, 94.7% of C.I. Acid Violet 109 from aqueous solution was decolorized (treatment time 15?min, enzyme concentration 0.15?IU/mL, hydrogen peroxide concentration 0.4?mM, dye concentration 30?mg/L, pH 4, and temperature 24°C) and 89.36% of C.I. Acid Blue 225 (32?min, enzyme concentration 0.15?IU/mL, hydrogen peroxide concentration 0.04?mM, dye concentration 30?mg/L, pH 5, and temperature 24°C). The mechanism of both reactions has been proven to follow the two substrate ping-pong mechanism with substrate inhibition, revealing the formation of a nonproductive or dead-end complex between dye and HRP or between H2O2 and the oxidized form of the enzyme. Both chemical oxygen demand and total organic carbon values showed that there was a reduction in toxicity after the enzymatic treatment. This study verifies the viability of use of horseradish peroxidase for the wastewaters treatment of similar anthraquinonic dyes. PMID:25685837

Šekuljica, Nataša Ž.; Prlainovi?, Nevena Ž.; Stefanovi?, Andrea B.; Žuža, Milena G.; ?i?kari?, Dragana Z.; Mijin, Dušan Ž.; Kneževi?-Jugovi?, Zorica D.

2015-01-01

237

Degradation of reactive, acid and basic textile dyes in the presence of ultrasound and rare earths [Lanthanum and Praseodymium].  

PubMed

Degradation of five textile dyes, namely Reactive Red 141 (RR 141), Reactive Blue 21 (RB 21), Acid Red 114 (AR 114), Acid Blue 113 (AB 113) and Basic Violet 16 (BV 16) in aqueous solution has been carried out with ultrasound (US) and in combination with rare earth ions (La(3+) and Pr(3+)). Kinetic analysis of the data showed a pseudo-first order degradation reaction for all the dyes. The rate constant (k), half life (t1/2) and the process efficiency (?) for various processes in degradation of dyes under different experimental conditions have been calculated. The influence of concentrations of dyes (16-40mg/L), pH (5, 7 and 9) and rare earth ion concentration (4, 12 and 20mg/L) on the degradation of dyes have also been studied. The degradation percentage increased with increasing rare earth amount and decreased with increasing concentration of dyes. Both horn and bath type sonicators were used at 20kHz and 250W for degradation. The sonochemical degradation rate of dyes in the presence of rare earths was related to the type of chromophoric groups in the dye molecule. Degradation sequence of dyes was further examined through LCMS and Raman spectroscopic techniques, which confirmed the sonochemical degradation of dyes to non-toxic end products. PMID:24491599

Srivastava, Pankaj; Goyal, Shikha; Patnala, Prem Kishore

2014-11-01

238

Silver nanoparticles doped agarose disk: highly sensitive surface-enhanced Raman scattering substrate for in situ analysis of ink dyes.  

PubMed

Raman spectroscopy is a preferred analytical tool for forensic trace analysis due to its non-invasive nature. This technique has been utilized in examination of organic colorants present in fibers and ink, but high fluorescent nature of these compounds is a problem. In the present study, silver-doped agarose gel disk, having property of quenching fluorescence and enhancing Raman signals, is found to be effective as surface-enhanced Raman scattering (SERS) substrates for analysis of rhodamine 6G (Rh 6G) and crystal violet (CV) dyes. As-prepared and well characterized by UV, TEM-EDAX and XRD techniques, the investigated silver-doped agarose gel disk proves to have minimal invasive as confirmed by the ATR-FTIR method and effective for in situ SERS analysis of blue and red ballpoint ink. The disk is stable upon storage and hence can be re-used and re-examined. The present method offers new possibilities in trace forensic analysis with minimal destruction. PMID:24314497

Raza, Ali; Saha, Basudeb

2013-12-10

239

Violet emission from flower-like bundle of ZnO nanosheets  

NASA Astrophysics Data System (ADS)

We report here the realization of a new flower-like bundle of zinc oxide (ZnO) nanosheets through a chemical synthesis route. For structural study and analysis, the fabricated nanostructures were characterized using the X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results of our investigation show a preferential growth by the selective capping of the different non-polar crystal planes in the ZnO nanocrystals. This is caused by the presence of hexamine that induces a preferred shape of the crystals. Our study of optical properties using photoluminescence and UV-visible spectroscopy reveals a strong violet emission which owes to the recombination of an electron in the zinc interstitial and a hole in the valance band. This structure is a new member in ZnO nanoresearch, and we demonstrate the visible emission properties of our chemically synthesized structures. These results should be useful in developing visible light-emitting and/nanophotonic devices.

Samanta, P. K.; Patra, S. K.; Roy Chaudhuri, P.

2009-02-01

240

TOPICAL REVIEW: InGaN-based violet laser diodes  

Microsoft Academic Search

High-efficiency light-emitting diodes emitting amber, green, blue and ultraviolet light have been obtained through the use of InGaN active layers instead of GaN active layers. The localized energy states caused by In composition fluctuation in the InGaN active layer seem to be related to the high efficiency of the InGaN-based emitting devices. Long-lifetime violet InGaN multi-quantum-well\\/GaN\\/AlGaN separate-confinement heterostructure laser diodes

S. Nakamura

1999-01-01

241

BRIEF COMMUNICATIONS: Attainment of a wide wavelength-tuning range in the green and red parts of the spectrum using new laser dyes  

NASA Astrophysics Data System (ADS)

A study was made of the lasing characteristics of two new dyes belonging to the naphthalimide and benzanthrone classes, when they were pumped with the second harmonic of ruby laser radiation. The emission wavelength could be tuned over a range of ~100 nm (from 500 to 600 nm in the case of naphthalimide and from 640 to 740 nm in the case of benzanthrone). The use of these compounds in lasers increased the output energy compared with the widely used coumarin 7 and uranin dyes in the green region or cresyl violet in the red region. Moreover, the new dyes ensured a considerably wider wavelength-tuning range.

Krymova, A. I.; Petukhov, V. A.

1986-03-01

242

Dyeing Wool with Fungi  

NSDL National Science Digital Library

In this activity (p.23 of PDF), learners dye wool with fungi. Learners discover that natural chemicals in fungi can dye wool different colors. Note: Natural dyeing normally requires a color fixative such as alum. This is not necessary if you use an aluminum, tin, or copper pot as the metal in the pot will take part in the dyeing reaction. However, if you use a non-stick saucepan you should add a few copper coins to the mix. Safety note: Always wash your hands after touching fungi! Adult supervision recommended.

Sue Assinder

2002-01-01

243

Hair Dye and Hair Relaxers  

MedlinePLUS

... For Consumers Consumer Information by Audience For Women Hair Dye and Hair Relaxers En Español Hair dye is used to ... products. If you have a bad reaction to hair dyes and relaxers, you should: Stop using the ...

244

Liquid crystal lasers Andrii Varanytsia  

E-print Network

Liquid crystal lasers Andrii Varanytsia Class: LC Optics and Photonics, Spring 2012 Instructor: Professor Peter Palffy-Muhoray 1 #12;Outline · Organic dye lasers and distributed feedback lasers · Liquid crystal laser · Methods of control and tuning liquid crystal laser emission · Methods of emission

Palffy-Muhoray, Peter

245

Tie-Dye Chemistry  

NSDL National Science Digital Library

In their travels to the indigo dye pits of northern Nigeria, the authors were struck by the beauty, history, and chemistry of indigo dyeing. They returned from Nigeria eager to develop a laboratory exercise that would expose students to the science of ind

Gretchen Cessna

2001-03-01

246

Oxazine laser dyes  

DOEpatents

New oxazine compounds useful as dye laser media in solution, are superiior to prior art materials. The oxazine dyes useful when pumped by the 578.2 nm copper line to operate in the 700-800 nm range are described by formula I ##STR1##

Hammond, Peter R. (Livermore, CA); Field, George F. (Danville, CA)

1992-01-01

247

Quasi-guest-host-effect liquid crystal displays: a new kind of positive contrast liquid crystal display device  

Microsoft Academic Search

A new kind of liquid crystal display (LCD) which positive dichroic dye disperses in LC is described in this paper. The quasi guest-host effect LCD is composed of a polarizer, twisted-nematic effect liquid crystal layer, and a guest- host effect liquid crystal layer which positive dichroic dye disperses in positive dielectric anisotropy nematic LC. Its multiplexing ability is as high

Jinggang Zhao; Zemin Yang; Zaigang Sun; Peng Sun; Junyu Sha; Jian Gao

1996-01-01

248

Monolithic dye laser amplifier  

DOEpatents

A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

Kuklo, T.C.

1993-03-30

249

Monolithic dye laser amplifier  

DOEpatents

A fluid dye laser amplifier for amplifying a dye beam by pump beams has a channel structure defining a channel through which a laseable fluid flows and the dye and pump beams pass transversely to one another through a lasing region. The channel structure is formed with two pairs of mutually spaced-apart and mutually confronting glass windows, which are interlocked and make surface-contacts with one another and surround the lasing region. One of the glass window pairs passes the dye beam and the other passes the pump beams therethrough and through the lasing region. Where these glass window pieces make surface-contacts, glue is used to join the pieces together to form a monolithic structure so as to prevent the dye in the fluid passing through the channel from entering the space between the mutually contacting glass window pieces.

Kuklo, Thomas C. (Ripon, CA)

1993-01-01

250

21 CFR 74.2602a - Ext. D&C Violet No. 2.  

Code of Federal Regulations, 2013 CFR

...Identity. The color additive Ext. D&C Violet...be avoided by good manufacturing practice: Sum of...restrictions. The color additive Ext. D&C Violet...consistent with good manufacturing practice. (d...label of the color additive shall conform to...

2013-04-01

251

21 CFR 74.2602a - Ext. D&C Violet No. 2.  

Code of Federal Regulations, 2014 CFR

...Identity. The color additive Ext. D&C Violet...be avoided by good manufacturing practice: Sum of...restrictions. The color additive Ext. D&C Violet...consistent with good manufacturing practice. (d...label of the color additive shall conform to...

2014-04-01

252

American Institute of Aeronautics and Astronautics Violet: A High-Agility Nanosatellite for Demonstrating  

E-print Network

American Institute of Aeronautics and Astronautics 092407 1 Violet: A High-Agility Nanosatellite University, Ithaca, NY, 14850 Violet is a highly agile nanosatellite whose primary mission-precision sensors, such as a star tracker and a fiber-optic rate gyroscope, with high-agility kinematics: 10 o /sec

Peck, Mason A.

253

Trend towards low cost, low power, ultra-violet (UV) based biological agent detectors  

Microsoft Academic Search

Ultra-violet fluorescence remains a corner stone technique for the detection of biological agent aerosols. Historically, these UV based detectors have employed relatively costly and power demanding lasers that have influenced the exploitation of the technology to wider use. Recent advancements from the Defense Advanced Research Project Agency's (DARPA) Solid-state Ultra Violet Optical Sources (SUVOS) program has changed this. The UV

David Sickenberger

2005-01-01

254

75 FR 977 - Carbazole Violet Pigment 23 From India: Preliminary Results of Countervailing Duty Administrative...  

Federal Register 2010, 2011, 2012, 2013, 2014

...C-533-839] Carbazole Violet Pigment 23 From India: Preliminary Results of Countervailing...carbazole violet pigment 23 (CVP-23) from India for the period January 1, 2007, through...production and export of CVP-23 from India. See ``Preliminary Results of...

2010-01-07

255

BRIEF COMMUNICATIONS: Investigation of the lasing characteristics of new laser dyes for the green and red parts of the spectrum  

NASA Astrophysics Data System (ADS)

An investigation was made of the lasing characteristics of solutions of various new dyes in the coumarin, naphthalimide, and benzanthrone classes pumped transversely by the second harmonic of ruby laser radiation. Lasing in the blue, green, and red parts of the spectrum was obtained for most of the compounds studied. A comparison was made between these materials and laser dyes widely used in these spectral ranges. The compounds studied included some with a lasing efficiency substantially higher than uranin in the green and cresyl violet in the red, and with a photostability not inferior to these two.

Krymova, A. I.; Petukhov, V. A.; Popov, M. B.

1985-10-01

256

Ultrafast photoinduced charge separation and recombination in weakly bound complexes between oxazine dyes and N,N-dimethylaniline  

NASA Astrophysics Data System (ADS)

The association constants between cresyl violet (CV) and oxazine 170 (OX) with N,N-dimethylaniline (DMA) were determined for methanolic solution to be 0.3±0.15 l/mol and 0.1±0.06 l/mol. One-colour pump—probe experiments showed a biphasic recovery of the ground state absorption. The short-lived component is assigned to the fast electron back-transfer within dye—amine complexes (1.4±0.2 ps for CV and 2.0±0.3 ps for OX), because the observed reduction in maximum bleaching parallels the amount of dye bound in weak complexes with DMA.

Schneider, Siegfried; Stammler, Wolfgang; Bierl, Rudolf; Jäger, Wighard

1994-03-01

257

Adaptation for improving lifetime of dye laser using coumarin dyes  

SciTech Connect

The effective lasing lifetime of laser dyes including coumarin dyes are significantly extended by the use of an inert cover gas for the laser dye solution such as argon in combination with the employment of a glass filter such as Pyrex disposed between the pumping flash lamp and the dye laser cavity capable of absorbing electromagnetic radiation of about 300 nanometers or shorter wavelength.

Fletcher, A.N.

1984-10-23

258

Dye system for dye laser applications  

DOEpatents

A dye of the DCM family, [2-methyl-6-[2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl]-4H-pyran -4-ylidene]-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

Hammond, Peter R. (Livermore, CA)

1991-01-01

259

The response characteristics of tetrazolium violet solutions to gamma irradiation  

NASA Astrophysics Data System (ADS)

The dosimetry characteristics of various solutions of tetrazolium violet, TV, (2,5-diphenyl-3-(1-naphthyl)-2H-tetrazolium chloride) to gamma irradiation are reported. The optical absorption spectra of these solutions show peaks between 400 and 600 nm with a shoulder at around 550 nm. The dose response of the optical absorbance values of aqueous and aqueous-alcoholic solutions containing different concentrations of TV was measured in the 250 Gy up to 75 kGy dose range. The formation of formazan product was observed due to radiolytic reduction in both solutions. Its formation was found more pronounced in N 2-saturated as well as in alkaline solutions. The results indicate that the 1 mM TV solution can be used for food irradiation and medical sterilization dosimetry at gamma irradiation facilities.

Emi-Reynolds, G.; Kovács, András; Fletcher, J. J.

2007-08-01

260

Ultra-violet indoor tanning addiction: a reinforcer pathology interpretation.  

PubMed

Ultra-violet indoor tanning (UVIT) is a pervasive issue that is increasing at record rates, despite obvious and well-publicized links to skin cancer. Recent studies on UVIT have found that frequent users face difficulty quitting and report symptomatology similar to substance-related disorders, causing the medical field to begin classifying excessive UVIT use as an addicting behavior. Despite calls for research, relatively little behavioral research has been aimed at determining the psychology of UVIT. This mini-review reinterprets the existing dermatology literature in light of the reinforcer pathology model of addiction. The relevancy of this model, in conjunction with the similarities between UVIT addiction and other substance-related addiction, suggests that behavioral economic research on UVIT is overdue. This mini-review concludes with directions for future research in this area. PMID:25452072

Reed, Derek D

2015-02-01

261

Investigation of picosecond relaxation processes in cresyl violet  

NASA Astrophysics Data System (ADS)

Picosecond population relaxation time of cresyl violet in methanol was measured by phase-conjugation type time-delayed four- wave mixing using incoherent light (TDFWM-IL). The excited state population relaxation time T1 is about 157 ps. Another important dynamical process, absorption recovery, was also studied by correlation technique of mode-locked picosecond coherent pulses with different intensities. The ground-state absorption recovery time Tar is about 162 ps. These results were analysed theoretically using the appropriate models. It is shown that the excited-state population relaxation and the ground-state absorption recovery occurred on a comparable time scale. When ? 32?0 especially, the medium becomes a two-level system, and the absorption recovery time is identical to the population relaxation time.

Liu, Junye; Huang, Shihua; Qin, Weiping; Yu, Jiaqi

1992-07-01

262

Vacuum ultra violet absorption spectroscopy of 193 nm photoresists  

NASA Astrophysics Data System (ADS)

193 nm photoresists which are methacrylate-based polymers are very sensitive to vacuum ultra violet (VUV) light (100 nm< ?<200 nm) generated by plasmas used for pattern transfer technologies. Upon plasma treatment the physical properties of the polymers can be deeply modified. To better understand the chemical changes involved, the absorption coefficient of a commercial 193 nm photoresist has been measured in the 120-280 nm wavelength range using a home built experimental set-up. The different contributions to the absorption were identified by also measuring the spectra of model polymers and simpler polymer chains. This knowledge was then used to identify the chemical changes in the photoresist upon heating up to 240°C.

Fouchier, M.; Pargon, E.; Azarnouche, L.; Menguelti, K.; Joubert, O.; Cardolaccia, T.; Bae, Y. C.

2011-11-01

263

VOLUME 88, NUMBER 14 P H Y S I C A L R E V I E W L E T T E R S 8 APRIL 2002 Broadband Fivefold Reduction of Vacuum Fluctuations Probed by Dyes in Photonic Crystals  

E-print Network

. P. Schriemer, Ad Lagendijk, and Willem L. Vos Van der Waals-Zeeman Instituut, Universiteit van, for which the dye emission is in the long wavelength limit. In this limit the DOS is quadratic in frequency

Vos, Willem L.

264

Chromonic liquid crystalline properties of dyes  

NASA Astrophysics Data System (ADS)

As a new class of lyotropic liquid crystals, chromonic liquid crystals (CLCs) can self-assemble into an ordered complex fluid, potentially useful for organic solar cells. Different from common amphiphilic lyotropic mesophases, CLCs have no optimum aggregation size, which implies the order parameter increases with concentration. We used capillary flow and magnetic field to induce alignment in chromonic dyes and studied the aggregation behavior by Vis-spectroscopy, the phase behavior by POM and DSC, and the order distribution by Raman Scattering. We also investigated how the molecular structures influence the structures of mesogens and the morphology in the dried film which will further influence the charge mobility in the solar cells.

Yao, Xuxia; Park, Jung; Srinivasarao, Mohan

2009-03-01

265

Hydrothermal synthesis, crystal structure, and vibrational and Mssbauer spectra of a new  

E-print Network

, Raman, and Mössbauer spectroscopy. The Fe(II) in the new orthophosphate salt must derive from leaching, and Janusz A. Kozinski Abstract: Crystals of a new potassium cobalt(II) iron(II) triorthophosphate salt, KCo3. The dark-violet crystals of the new salt have been characterized by single-crystal X-ray diffraction and IR

Ryan, Dominic

266

Azo dye biodecolorization enhanced by Echinodontium taxodii cultured with lignin.  

PubMed

Lignocellulose facilitates the fungal oxidization of recalcitrant organic pollutants through the extracellular ligninolytic enzymes induced by lignin in wood or other plant tissues. However, available information on this phenomenon is insufficient. Free radical chain reactions during lignin metabolism are important in xenobiotic removal. Thus, the effect of lignin on azo dye decolorization in vivo by Echinodontium taxodii was evaluated. In the presence of lignin, optimum decolorization percentages for Remazol Brilliant Violet 5R, Direct Red 5B, Direct Black 38, and Direct Black 22 were 91.75% (control, 65.96%), 76.89% (control, 43.78%), 43.44% (control, 17.02%), and 44.75% (control, 12.16%), respectively, in the submerged cultures. Laccase was the most important enzyme during biodecolorization. Aside from the stimulating of laccase activity, lignin might be degraded by E. taxodii, and then these degraded low-molecular-weight metabolites could act as redox mediators promoting decolorization of azo dyes. The relationship between laccase and lignin degradation was investigated through decolorization tests in vitro with purified enzyme and dozens of aromatics, which can be derivatives of lignin and can function as laccase mediators or inducers. Dyes were decolorized at triple or even higher rates in certain laccase-aromatic systems at chemical concentrations as low as 10 µM. PMID:25285777

Han, Yuling; Shi, Lili; Meng, Jing; Yu, Hongbo; Zhang, Xiaoyu

2014-01-01

267

Azo Dye Biodecolorization Enhanced by Echinodontium taxodii Cultured with Lignin  

PubMed Central

Lignocellulose facilitates the fungal oxidization of recalcitrant organic pollutants through the extracellular ligninolytic enzymes induced by lignin in wood or other plant tissues. However, available information on this phenomenon is insufficient. Free radical chain reactions during lignin metabolism are important in xenobiotic removal. Thus, the effect of lignin on azo dye decolorization in vivo by Echinodontium taxodii was evaluated. In the presence of lignin, optimum decolorization percentages for Remazol Brilliant Violet 5R, Direct Red 5B, Direct Black 38, and Direct Black 22 were 91.75% (control, 65.96%), 76.89% (control, 43.78%), 43.44% (control, 17.02%), and 44.75% (control, 12.16%), respectively, in the submerged cultures. Laccase was the most important enzyme during biodecolorization. Aside from the stimulating of laccase activity, lignin might be degraded by E. taxodii, and then these degraded low-molecular-weight metabolites could act as redox mediators promoting decolorization of azo dyes. The relationship between laccase and lignin degradation was investigated through decolorization tests in vitro with purified enzyme and dozens of aromatics, which can be derivatives of lignin and can function as laccase mediators or inducers. Dyes were decolorized at triple or even higher rates in certain laccase–aromatic systems at chemical concentrations as low as 10 µM. PMID:25285777

Meng, Jing; Yu, Hongbo; Zhang, Xiaoyu

2014-01-01

268

Molecular Models of Dyes  

NSDL National Science Digital Library

The paper on the synthesis of several dyes by James V. McCullagh and Kelly A. Daggett (1) provides us with the JCE Featured Molecules for this month. The authors mention various applications of these dyes, ranging from commercial dyeing to techniques for determining the course of complex biochemical processes. One of the reaction products, rhodamine B, is a member of a family of molecules that are widely used as tunable laser dyes. In this application, the rhodamines are most commonly encountered in a cationic form, rather than in the neutral form shown in the paper. In the cations, the carboxyl group is no longer part of a ring system. Several different members of the rhodamine family are included in the molecule collection because substituents have a marked effect on the effective lasing range of a given dye. Additionally, the solvent and the excitation source also influence the lasing range (2). Students can learn more about the relationship between structure, absorption and emission properties, and lasing ranges of various dyes by consulting ref 2 and from PhotochemCAD, Jonathan Lindsey's free application (3).

269

Solid hosts for dye laser rods: Part 1, Criteria for choosing a host material  

SciTech Connect

This paper will attempt to provide selection criteria for polymers as hosts for flashlamp-pumped dye laser rods. The properties of transparent polymer materials are compared with typical inorganic crystal and glass hosts. 2 figs., 1 tab.

Erickson, G.F.

1987-01-01

270

TOPICAL REVIEW: InGaN-based violet laser diodes  

NASA Astrophysics Data System (ADS)

High-efficiency light-emitting diodes emitting amber, green, blue and ultraviolet light have been obtained through the use of InGaN active layers instead of GaN active layers. The localized energy states caused by In composition fluctuation in the InGaN active layer seem to be related to the high efficiency of the InGaN-based emitting devices. Long-lifetime violet InGaN multi-quantum-well/GaN/AlGaN separate-confinement heterostructure laser diodes (LDs) were successfully fabricated using epitaxially laterally overgrown GaN by reducing a large number of threading dislocations originating from the interface between GaN and sapphire substrate. The threading dislocations shorten the lifetime of the LDs through an increase of the threshold current density. The LDs with cleaved mirror facets showed an output power as high as 30 mW under room-temperature continuous-wave (CW) operation with a stable fundamental transverse mode. The lifetime of the LDs at a constant output power of 5 mW was estimated to be approximately 3000 h under CW operation at an ambient temperature of 50 °C. These results indicate that these LDs already can be used for many real applications, such as digital versatile disks, laser printers, sensors and exciting light sources as a commercial product with a high output power and a high reliability.

Nakamura, S.

1999-06-01

271

Solar ultra-violet radiation changes in Bahrain  

NASA Astrophysics Data System (ADS)

Long-term changes in solar ultra-violet radiation (UV) of wavelengths 295 to 385 nm were measured in Bahrain. A tendency occurred towards a reduction in UV intensity during the months of June, July, August and September in each year. A calculation was made, and averaged, over several years regarding the ratio of UV intensity for each month to the average global solar radiation for that month, on a horizontal surface. The average annual ratio was found to be 3.87% with a lowest value of 3.3% and a highest value of 4.35%. The measured UV intensity in Bahrain was compared with those measured in countries in the Arabian Gulf, Middle East, Northern Europe and in Alaska. An empirical equation has been developed which estimates the monthly average UV intensity, with a maximum monthly percentage error of not more than 24%. This equation contains only three variables, namely humidity, sunshine fraction and extra-terrestrial solar radiation.

Alnaser, W. E.

1997-05-01

272

21 CFR 74.3602 - D&C Violet No. 2.  

Code of Federal Regulations, 2010 CFR

...LISTING OF COLOR ADDITIVES SUBJECT TO CERTIFICATION Medical Devices § 74.3602 D&C Violet No. 2. (a) Identity...Food, Drug, and Cosmetic Act with respect to the medical devices in which the color additive is used. (c)...

2010-04-01

273

Kinetics of azoreductase and assessment of toxicity of metabolic products from azo dyes by Pseudomonas luteola.  

PubMed

This is a continuous study on a decolorization strain, Pseudomonas luteola, which involves treating seven azo dyes with different structures. This study focuses mainly on determining both the mechanism of decolorization by P. luteola and the activity of azoreductase from P. luteola as well as identifying and assessing the toxicity of metabolic products of azo dyes. The growth of P. luteola reached the stationary phase after shaking incubation for 24 hours. Then, while being kept static, the color of seven tested azo dyes (100 mg/l) could be removed. The proportion of color removal was between 59-99%, which figure is related to the structure of the dye. Monoazo dyes (RP2B, V2RP and Red 22) showed the fastest rate of decolorization, i.e. from 0.23-0.44 mg dye-mg cell-1 hr-1. P. luteola could remove the color of V2RP and a leather dye at a concentration of 200 mg/l, and as to the rest of the azo dyes, it could remove at a concentration of up to 100 mg/l. Decolorization of RP2B and Red 22 required activation energy of 7.00 J/mol and 6.63 J/mole, respectively, indicating that it was easier for azoreductase to decolorize structurally simple dyes. The kinetics of azoreductase towards seven azo dyes suggested a competitive inhibition model be applied. Microtox was used to analyze the toxicity of the metabolic products of azo dyes. EC50 showed differences in toxicity before and after the azo dyes had been metabolized. Analysis revealed significant differences between the results obtained by EC50 with Blue 15 and those obtained with the leather dye, indicating that the toxicities of the metabolic products were increased. The differences obtained by EC50 with Red 22, RP2P and V2RP were small, and Black 22 showed no such difference. Sulfanic acid and orthanilic acid may be the intermediate products of Violet 9 and RP2B, respectively. However, according to FT-IR analysis, aromatic amines were present in the metabolic product. PMID:11380189

Hu, T L

2001-01-01

274

Solution processed multilayer cadmium-free blue/violet emitting quantum dots light emitting diodes  

NASA Astrophysics Data System (ADS)

We demonstrate blue/violet emitting devices based on cadmium-free zinc selenide/zinc sulfide core/shell quantum dots. Using poly(N-vinylcarbazole) with a low lying highest occupied molecular orbital energy for the hole transporting layer, enhanced hole injection was observed, resulting in efficient blue/violet emitting devices. The device charge balance was further enhanced by tuning the thicknesses of the hole transporting layer and quantum dot emitting layer.

Xiang, Chaoyu; Koo, Wonhoe; Chen, Song; So, Franky; Liu, Xiong; Kong, Xiangxing; Wang, Yunjun

2012-07-01

275

Propagation and chimeral characterization of two reverse pinwheel flowering African violet clones  

E-print Network

PROPAGATION AND CHIMERAL CHARACTERIZATION OF TWO REVERSE P~EL FLOWERING AFRICAN VIOLET CLONES A Thesis by SHARON KATRINA SANDALL Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 2002 Major Subject: Horticulture PROPAGATION AND CHIMERAL CHARACTERIZATION OF TWO REVERSE PINWHEEL FLOWERING AFRICAN VIOLET CLONES A Thesis by SHARON KATRINA SANDALL Submitted to Texas A&M University...

Sandall, Sharon Katrina

2002-01-01

276

Observation of vibronic quantum beat in dye-doped polymers using femtosecond accumulated photon echo  

NASA Astrophysics Data System (ADS)

Fourier-transform photon echo spectroscopy has been applied to the vibronic absorption band in dye molecule. The quantum beat between the vibronic lines has been observed in cresyl-violet and tetraphenyl-porphine doped in polymer films. The vibronic lines associated with the quantum beat have been identified with comparing the Fourier-transformed spectrum of the echo signal and the persistent hole-burning spectrum. The observed steep temperature dependence of the vibronic coherence has been discussed in comparison with the mild temperature dependence of vibrational coherence (sublevel coherence between vibronic states).

Saikan, S.; Nakabayashi, T.; Kanematsu, Y.; Imaoka, A.

1988-10-01

277

Water soluble laser dyes  

DOEpatents

Novel water soluble dyes of the formula 1 are provided by the formula described in the paper wherein R{sup 1} and R{sup 4} are alkyl of 1 to 4 carbon atoms or hydrogen; or R{sup 1}--R{sup 2} or R{sup 2}--R{sup 4} form part of aliphatic heterocyclic rings; R{sup 2} is hydrogen or joined with R{sup 1} or R{sup 4} as described above; R{sup 3} is --(CH{sub 2}){sub m}--SO{sub 3}{sup {minus}}, where m is 1 to 6; X is N, CH or formula 2 given in paper where Y is 2 --SO{sub 3}{sup {minus}} ; Z is 3, 4, 5 or 6 --SO{sub 3}{sup {minus}}. The novel dyes are particularly useful as the active media in water solution dye lasers.

Hammond, P.R.; Feeman, J.F.; Field, G.F.

1998-08-11

278

Hair cosmetics: dyes.  

PubMed

Hair plays a significant role in body image, and its appearance can be changed relatively easily without resort to surgical procedures. Cosmetics and techniques have therefore been used to change hair appearance since time immemorial. The cosmetics industry has developed efficient products that can be used on healthy hair or act on concomitant diseases of the hair and scalp. Dyes embellish the hair by bleaching or coloring it briefly, for temporary periods of longer duration, or permanently, depending on the composition of a dye (oxidative or nonoxidative) and its degree of penetration of the hair shaft. The dermatologist's knowledge of dyes, their use, and their possible side effects (contact eczema, cancer, increased porosity, brittleness) can extend to an understanding of cosmetic resources that also treat hair and scalp conditions. PMID:24656996

Guerra-Tapia, A; Gonzalez-Guerra, E

2014-11-01

279

Water soluble laser dyes  

DOEpatents

Novel water soluble dyes of the formula I are provided ##STR1## wherein R.sup.1 and R.sup.4 are alkyl of 1 to 4 carbon atoms or hydrogen; or R.sup.1 -R.sup.2 or R.sup.2 -R.sup.4 form part of aliphatic heterocyclic rings; R.sup.2 is hydrogen or joined with R.sup.1 or R.sup.4 as described above; R.sup.3 is --(CH.sub.2).sub.m --SO.sub.3.sup.-, where m is 1 to 6; X is N, CH or ##STR2## where Y is 2 --SO.sub.3.sup.- ; Z is 3, 4, 5 or 6 --SO.sub.3.sup.-. The novel dyes are particularly useful as the active media in water solution dye lasers.

Hammond, Peter R. (Livermore, CA); Feeman, James F. (Wyomissing, PA); Field, George F. (Santa Ana, CA)

1998-01-01

280

Dye-multilayer semiconductor nanostructures  

Microsoft Academic Search

Broadening of the spectral response of dye-sensitized semiconductor devices is one of the major issues confronting practical application of dye-sensitization. It is the main factor limiting the energy conversion efficiencies of dye-sensitized solar cells. Synthesis of dyes with broader spectral response has been attempted as a possible strategy. The other method is to adopt more than one pigment. However, the

P. K. D. Duleepa P. Pitigala; M. K. Indika Senevirathna; V. P. Susira Perera; Kirthi Tennakone

2006-01-01

281

Dye filled security seal  

DOEpatents

A security seal for providing an indication of unauthorized access to a sealed object includes an elongate member to be entwined in the object such that access is denied unless the member is removed. The elongate member has a hollow, pressurizable chamber extending throughout its length that is filled with a permanent dye under greater than atmospheric pressure. Attempts to cut the member and weld it together are revealed when dye flows through a rupture in the chamber wall and stains the outside surface of the member.

Wilson, Dennis C. W. (Tijeras, NM)

1982-04-27

282

Identification of methyl violet 2B as a novel blocker of focal adhesion kinase signaling pathway in cancer cells  

SciTech Connect

Highlights: •FAK signaling cascade in cancer cells is profoundly inhibited by methyl violet 2B. •Methyl violet 2B identified by virtual screening is a novel allosteric FAK inhibitor. •Methyl violet 2B possesses extremely high kinase selectivity. •Methyl violet 2B suppresses strongly the proliferation of cancer cells. •Methyl violet 2B inhibits focal adhesion, invasion and migration of cancer cells. -- Abstract: The focal adhesion kinase (FAK) signaling cascade in cancer cells was profoundly inhibited by methyl violet 2B identified with the structure-based virtual screening. Methyl violet 2B was shown to be a non-competitive inhibitor of full-length FAK enzyme vs. ATP. It turned out that methyl violet 2B possesses extremely high kinase selectivity in biochemical kinase profiling using a large panel of kinases. Anti-proliferative activity measurement against several different cancer cells and Western blot analysis showed that this substance is capable of suppressing significantly the proliferation of cancer cells and is able to strongly block FAK/AKT/MAPK signaling pathways in a dose dependent manner at low nanomolar concentration. Especially, phosphorylation of Tyr925-FAK that is required for full activation of FAK was nearly completely suppressed even with 1 nM of methyl violet 2B in A375P cancer cells. To the best of our knowledge, it has never been reported that methyl violet possesses anti-cancer effects. Moreover, methyl violet 2B significantly inhibited FER kinase phosphorylation that activates FAK in cell. In addition, methyl violet 2B was found to induce cell apoptosis and to exhibit strong inhibitory effects on the focal adhesion, invasion, and migration of A375P cancer cells at low nanomolar concentrations. Taken together, these results show that methyl violet 2B is a novel, potent and selective blocker of FAK signaling cascade, which displays strong anti-proliferative activities against a variety of human cancer cells and suppresses adhesion/migration/invasion of tumor cells.

Kim, Hwan [Chemical Kinomics Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of) [Chemical Kinomics Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Translational Research Center for Protein Function Control (TRCP), Department of Biotechnology and Department of Biomedical Sciences (WCU Program), Yonsei University, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kim, Nam Doo [Daegu-Gyeongbuk Medical Innovation Foundation, 2387 Dalgubeol-daero, Suseong-gu, Daegu 706-010 (Korea, Republic of)] [Daegu-Gyeongbuk Medical Innovation Foundation, 2387 Dalgubeol-daero, Suseong-gu, Daegu 706-010 (Korea, Republic of); Lee, Jiyeon [Chemical Kinomics Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)] [Chemical Kinomics Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Han, Gyoonhee [Translational Research Center for Protein Function Control (TRCP), Department of Biotechnology and Department of Biomedical Sciences (WCU Program), Yonsei University, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)] [Translational Research Center for Protein Function Control (TRCP), Department of Biotechnology and Department of Biomedical Sciences (WCU Program), Yonsei University, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Sim, Taebo, E-mail: tbsim@kist.re.kr [Chemical Kinomics Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of) [Chemical Kinomics Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); KU-KIST Graduate School of Converging Science and Technology, 145, Anam-ro, Seongbuk-gu, Seoul 136-713 (Korea, Republic of)

2013-07-26

283

Liquid Crystal Displays  

Microsoft Academic Search

This paper reviews the present status and art of liquid crystal displays. It discusses the fabrication and operational principles of dynamic scattering, twisted nematic, guest-host, dye phase change, tunable birefingence, thermally addressed smectic A mode, etc, displays. The potentialities of applications of these displays are examined critically. Twisted nematic mode displays, which capture over 99% of today's LCD market, is

Birendra Bahadur

1984-01-01

284

Investigation of ultra violet (UV) resistance for high strength fibers  

NASA Astrophysics Data System (ADS)

Ultra long duration balloons (ULDB), currently under development by the National Aeronautics and Space Administration (NASA), requires the use of high strength fibers in the selected super-pressure pumpkin design. The pumpkin shape balloon concept allows clear separation of the load transferring functions of the major structural elements of the pneumatic envelope, the tendons and the film. Essentially, the film provides the gas barrier and transfers only local pressure load to the tendons. The tendons, in the mean time, provide the global pressure containing strength. In that manner, the strength requirement for the film only depends on local parameters. The tendon is made of p-phenylene-2,6-benzobisoxazole (PBO) fibers, which is selected due to its high strength to weight ratio when compared to other high performance, commercially available, fibers. High strength fibers, however, are known to degrade upon exposure to light, particularly at short wavelengths. This paper reports the results of an investigation of the resistance of four commercial high strength fibers to ultra violet (UV) exposure. The results indicate that exposing high strength fibers in continuous yarn form to UV led to serious loss in strength of the fibers except for Spectra® fibers. The adverse changes in mechanical behavior occurred over short duration of exposure compared to the 100 day duration targeted for these missions. UV blocking finishes to improve the UV resistance of these fibers are being investigated. The application of these specially formulated coatings is expected to lead to significant improvement of the UV resistance of these high performance fibers. In this publication, we report on the mechanical behavior of the fibers pre- and post-exposure to UV, but without application of the blocking finishes.

Said, M. A.; Dingwall, Brenda; Gupta, A.; Seyam, A. M.; Mock, G.; Theyson, T.

285

Vegetable Dyeing of Wool  

ERIC Educational Resources Information Center

In keeping with the Bicentennial celebration, many art teachers will find themselves "looking back" to crafts of the American past. Dyeing is certainly one that was used extensively and here a professor in a Fine Arts Department details how the process takes place. (Author/RK)

Greenberg, Pearl

1976-01-01

286

Circularly polarized high-efficiency cholesteric liquid crystal lasers with a tunable  

E-print Network

of highly ordered polymer-dyes for lasing in chiral nematic liquid crystals," Jpn. J. Appl. Phys. 43(2), 631Circularly polarized high-efficiency cholesteric liquid crystal lasers with a tunable nematic phase-doped cholesteric liquid crystal (CLC) is demonstrated by optimizing the dye concentration and using an electrically

Wu, Shin-Tson

287

High efficiency cholesteric liquid crystal lasers with an external stable resonator  

E-print Network

, "Advantages of highly ordered polymer-dyes for lasing in chiral nematic liquid crystals," Jpn. J. Appl. PhysHigh efficiency cholesteric liquid crystal lasers with an external stable resonator Hamidreza cholesteric liquid crystal (CLC) laser performance is demonstrated by utilizing a binary-dye mixture (with 62

Richardson, Martin C.

288

Photochemistry of coumarin laser dyes  

SciTech Connect

Coumarin laser dyes are widely used in dye lasers for the generation of tunable laser light in the blue-green spectral region. As in the case with most laser dyes, coumarin dyes undergo photochemical reactions that interfere with simulated emission and result in loss of laser power output. This thesis describes the photochemistry of coumarin laser dyes under both anaerobic and aerobic conditions and some attempts to extend the useful lifetime of several dyes in dye lasers. Irradiation of Coumarin 311, 7-dimethylamino-4-methyl-coumarin (15), in oxygen-free ethanol solution results in the inefficient dye destruction. Products formed absorb light at the lasing wavelength of the dye, interfere with stimulated emission, and decrease the power output of the dye laser. Addition of the sulfur free radical chain transfer agents ethanethiol and ethyl disulfide retard the rate of formation of photoproducts absorbing at the lasing wavelengths. Deuterium incorporation, from the irradiation of Coumarin 311 in the presence of ethanethiol-S-d and ethyl disulfide, indicates that photoproducts most likely result from the reactions of free radicals which are generated in a bimolecular reaction between excited Coumarin 311 and ground state Coumarin 311. Ethanethiol and ethyl disulfide are shown to decrease the rate of power loss from a Coumarin 1 (3) dye laser. The naturally occurring amino acid cysteine acts similarly.

von Trebra, R.J.

1984-01-01

289

Intermittent Single-molecule Interfacial Electron Transfer Dynamics in Dye-TiO2 Nanoparticle systems  

NASA Astrophysics Data System (ADS)

Photosensitized interfacial electron transfer dynamics of single molecules of Coumarin 343 (C343) and Cresyl Violet (CV+) acetate dyes adsorbed at TiO2 nanoparticle (NP)-polymer and TiO2 NP-electrolyte interfaces are studied using single-molecule photon-stamping fluorescence spectroscopy. Fluorescence intensity trajectories of individual dye molecules adsorbed at a TiO2 NP-polymer interface in air showed intermittent 'on' and 'off' (blinking) fluorescence in sub-second to second time scales, which are well distinguished from blinking due to intersystem crossing to dark triplet state. Autocorrelation analyses of the intensity trajectories showed non-exponential fluctuation dynamics for the single molecules, and the average rates are of 5 s-1 for both the C343-TiO2 and CV+-TiO2 systems. We attribute the fluorescence intensity fluctuation to the intermittency of the single-molecule interfacial electron transfer reactivity and dynamics.

Biju, Vasudevanpillai; Micic, Miodrag; Hu, Dehong; Lu, H. Peter

2004-03-01

290

Studies of solvent-solute interactions in the photophysics of laser dyes  

SciTech Connect

The fluorescence lifetime of rhodamine B in the normal alcohols and normal nitriles was measured using a picosecond laser system. The lifetime-measuring technique is time-correlated single photon counting (TCSPC). Absorption and emission spectra of rhodamine B in the alcohols and nitriles have also been determined, thus allowing calculation of quantum yields, radiative, and nonradiative rates. The rotation of the dye's diethylamino groups is related to the nonradiative rate. A decreasing nonradiative rate corresponds to a greater energy barrier to rotation. Rotational relaxation times of two laser dyes (cresyl violet and oxazine-1) in polymer solution (poly(ethylene oxide) and methanol) was measured using the transient absorption spectroscopy (TAS) method. TAS is a pump-probe technique using a picosecond laser system. The pump beam optically bleaches the sample and the probe beam monitors the transient response. The effect of increasing polymer concentration is seen as an increasing rotational relaxation time.

Casey, K.G.

1988-01-01

291

Stark effect and spectral hole-burning: solvation of organic dyes in polymers  

NASA Astrophysics Data System (ADS)

Spectral hole-burning studies of nile red and cresyl violet in polyvinylbutyral and polyvinylformal films have been performed. From the shape of spectral holes under the influence of an electric field, the dipole moment difference between the ground and excited state of both dyes has been determined. The Stark effect was investigated at different positions in the inhomogeneously broadened absorption band of the guest molecules. The observed dipole moment difference decreases with increasing wavelength. This variation is caused by the matrix induced dipole moment. For nile red, which is a neutral and polar molecule, the distribution of induced dipole moments is strongly correlated with the orientation of its ground state dipole moment. In the case of cresyl violet perchlorate, which is a salt, this distribution is anisotropic for guests absorbing in the blue part of the inhomogeneous band but becomes more isotropic as the absorption wavelength increases. The wavelength dependence of the observed dipole moment is much stronger and is ascribed to the existence of the cresyl violet perchlorate salt in different states of solvation.

Vauthey, Eric; Holliday, Keith; Wei, Changjiang; Renn, Alois; Wild, Urs P.

1993-04-01

292

Dye-modified nanochannel materials for photoelectronic and optical devices.  

PubMed

Artificial photonic antenna systems have been realised by incorporating organic dyes into zeolite L. The size and aspect ratio of the cylindrically shaped zeolite crystals can be tuned over a wide range, adding to the versatility of this host material. A 600 nm sized crystal, for example, consists of about 96 000 one-dimensional channels oriented parallel to the cylinder axis. Geometrical constraints imposed by the host structure lead to supramolecular organisation of the guests, allowing high concentrations of non- or only very weakly interacting dye molecules. A special twist is added to these systems by plugging the channel openings with a second type of fluorescent dye, a so-called stopcock molecule. The two types of molecules are precisely tuned to each other; the stopcocks are able to accept excitation energy from the dyes in the channels, but cannot pass it back. The supramolecular organisation of dyes in the zeolite channels corresponds to a first stage of organisation, allowing light-harvesting within the volume of a cylindrical crystal and radiationless energy transport to either the cylinder ends or centre. The second stage of organisation represents the coupling to an external acceptor or donor stopcock fluorophore at the channel entrances, which can then trap or inject electronic excitation energy. The third stage of organisation is realised by interfacing the material to an external device through a stopcock intermediate. We observed that electronic-excitation-energy transfer in dye-zeolite L materials occurs mainly along the channel axis and we have shown that macroscopically organised materials can be prepared. The new materials offer unique possibilities as building blocks for optical, electro-optical and sensing devices. PMID:18626875

Calzaferri, Gion; Li, Huanrong; Brühwiler, Dominik

2008-01-01

293

A pilot plant study of the degradation of Brilliant Green dye using ozone microbubbles: mechanism and kinetics of reaction.  

PubMed

Oxidation of Brilliant Green dye was performed using ozone microbubbles in a pilot plant scale. Decolourisation was very effective at both acidic and alkaline pH. The colour of the aqueous solution was below detectable limit after 30?min at 1.7?mg/s ozone generation rate. The reaction between the dye and ozone was first-order in nature with respect to both ozone and the dye. The enhancement factor increased with increasing dye concentration. The samples were analysed by the ultra-violet-visible (UV-Vis) spectrophotometry, gas chromatography-mass spectrometry (GC-MS) and Fourier transform infra-red (FTIR) spectroscopy. From the GC-MS analysis, 13 intermediates were detected as oxidation products of this dye at various stages of oxidation. The changes in the FTIR spectra showed the destruction of the dye and the formation of new compounds. The oxidation mechanism was divided into two reaction pathways. The mineralisation of Brilliant Green was up to 80% in 60?min, as determined by total organic carbon analysis. PMID:25514135

Khuntia, Snigdha; Majumder, Subrata Kumar; Ghosh, Pallab

2015-02-01

294

Infrared multiple photon dissociation (IRMPD) spectroscopy of oxazine dyes.  

PubMed

The structure and energetic properties of four common oxazine dyes, Nile red, Nile blue A, Cresyl violet, and Brilliant cresyl blue, have been probed using a combination of infrared multiple-photon dissociation (IRMPD) spectroscopy and quantum chemical calculations. IRMPD spectra of the protonated dyes, as generated from an electrospray ionization (ESI) source, were collected in the range of 900-1800 cm(-1). Vibrational band assignments related to carbonyl and substituted-amine stretches were established from a comparison of the experimental spectra of these related systems as well as from a comparison with spectra generated by density functional theory (DFT) calculations. For Nile red, the thermochemical landscape for protonation at different basic sites was probed using DFT; comparison of IRMPD and calculated IR spectra reveals the site of protonation to be at the carbonyl oxygen. The structural information obtained here in the gas phase pertaining to these important fluorophores is anticipated to provide further insight into their associated intrinsic fluorescent properties in solution. PMID:23450155

Nieckarz, Robert J; Oomens, Jos; Berden, Giel; Sagulenko, Pavel; Zenobi, Renato

2013-04-14

295

Painting With Natural Dyes  

NSDL National Science Digital Library

This activity is part of an integrated elementary unit called "Painted Tipis." The unit is best taught in the fall in conjunction with the September celebration "American Indian Heritage Week." It integrates lessons on literature through legends and myths, language (Blackfeet), and mathematics through structural components of the tipi. The activity introduces the students to the art of dyeing as used in ancestral tipi paintings. Historical cultural ties are an integral part of the Native American students learning and this unit provides those connections. The purpose of this lesson is to provide elementary students with the opportunity to explore, identify and locate area plants. The inquiry cooperative learning component of this lesson will be to determine the color (dye) producing possibilities of the plant. Students will also plan and carry out an experiment to produce the dyestuff of the plant as well as create possible mordants, which is a chemical or metallic compound that will "fasten" the color to the fabric.

Barbara Arrowtop (Heart Butte School)

1999-07-01

296

Dyeing of wool with natural anthraquinone dyes from Fusarium oxysporum  

Microsoft Academic Search

Two anthraquinone compounds are described which were produced by liquid cultures of Fusarium oxysporum (isolate no. 4), isolated from the roots of citrus trees affected with root rot disease. These anthraquinone compounds are 2-acetyl-3,8-dihydroxy-6-methoxy anthraquinone or 3-acetyl-2,8-dihydroxy-6-methoxy anthraquinone. Dyeing of wool fabrics with these new anthraquinone compounds as natural dyes has been studied. The values of dyeing rate constant, half-time

F. A. Nagia; R. S. R. EL-Mohamedy

2007-01-01

297

Optimization of dyeing poly(lactic acid) fibers with vat dyes  

Microsoft Academic Search

Optimization of dyeing poly(lactic acid) fibers with vat dyes has been investigated. Conventional method for dyeing cellulose fibers with vat dyes was able to be applied for dyeing poly(lactic acid) fibers. It has become obvious that higher dyeing temperature and concentration of auxiliaries have negative effects on the dyeability of dyes on poly(lactic acid) fibers. Determination of optimal dyeing condition

K. Sawada; M. Ueda

2007-01-01

298

Cold Pad-Batch dyeing method for cotton fabric dyeing with reactive dyes using ultrasonic energy.  

PubMed

Reactive dyes are vastly used in dyeing and printing of cotton fibre. These dyes have a distinctive reactive nature due to active groups which form covalent bonds with -OH groups of cotton through substitution and/or addition mechanism. Among many methods used for dyeing cotton with reactive dyes, the Cold Pad Batch (CPB) method is relatively more environment friendly due to high dye fixation and non requirement of thermal energy. The dyed fabric production rate is low due to requirement of at least twelve hours batching time for dye fixation. The proposed CPB method for dyeing cotton involves ultrasonic energy resulting into a one third decrease in batching time. The dyeing of cotton fibre was carried out with CI reactive red 195 and CI reactive black 5 by conventional and ultrasonic (US) method. The study showed that the use of ultrasonic energy not only shortens the batching time but the alkalis concentrations can considerably be reduced. In this case, the colour strength (K/S) and dye fixation (%F) also enhances without any adverse effect on colour fastness of the dyed fabric. The appearance of dyed fibre surface using scanning electron microscope (SEM) showed relative straightening of fibre convolutions and significant swelling of the fibre upon ultrasonic application. The total colour difference values ?E (CMC) for the proposed method, were found within close proximity to the conventionally dyed sample. PMID:21550289

Khatri, Zeeshan; Memon, Muhammad Hanif; Khatri, Awais; Tanwari, Anwaruddin

2011-11-01

299

Dye-coated europium monosulfide  

SciTech Connect

Nanoparticles of EuS were synthesized using europium dithiocarbamate complexes. The resulting nanoparticles were coated with the dye, 1-pyrene carboxylic acid and the resulting material was characterized using X-ray powder diffraction, TEM, and UV-visible spectroscopy. Fluorescence spectroscopy was used to determine the relative energy of the conduction band edge to the excited state energy of the dye. -- Graphical abstract: Dye sensitized magnetic semiconductor materials were prepared by synthesizing EuS nanoparticles using single source precursors and coating with the dye, 1-pyrene carboxylic acid. Display Omitted highlights: > Synthesized EuS nanoparticles, 11{+-}2.4 nm characterized using XRD, TEM, and UV-vis. spect. > Grafted a dye to the surface and characterized the product using XRD, FTIR, UV-vis., and TEM. > Studied the photophysical properties using fluorescence spectroscopy. > Determined the relative dye excited state to the conduction band of the semiconductor.

Kar, Srotoswini [Department of Chemistry, Georgetown University, Washington D.C. 20057 (United States); Dollahon, Norman R. [Department of Biology, Villanova University, Villanova, PA 19085 (United States); Stoll, Sarah L., E-mail: sls55@georgetown.ed [Department of Chemistry, Georgetown University, Washington D.C. 20057 (United States)

2011-05-15

300

White light emission from polystyrene under pulsed ultra violet laser irradiation  

PubMed Central

This paper reports for the first time the luminescent property of polystyrene (PS), produced by pulsed ultra violet laser irradiation. We have discovered that, in air, ultra-violet (UV) irradiated PS nanospheres emit bright white light with the dominant peak at 510?nm, while in vacuum they emit in the near-blue region. From the comparison of PS nanospheres irradiated in vacuum and air, we suggest that the white luminescence is due to the formation of carbonyl groups on the surface of PS by photochemical oxidation. Our results potentially offer a new route and strategy for white light sources. PMID:24247038

Kim, Eunkyeom; Kyhm, Jihoon; Kim, Jung Hyuk; Lee, Gi Yong; Ko, Doo-Hyun; Han, Il Ki; Ko, Hyungduk

2013-01-01

301

A comparative study on the properties, mechanisms and process designs for the adsorption of non-ionic or anionic dyes onto cationic-polymer/bentonite.  

PubMed

The adsorption properties and mechanisms of a cationic-polymer/bentonite complex (EPI-DMA/bentonite), prepared from polyepicholorohydrin-dimethylamine and bentonite, for non-ionic dyes (Disperse Blue SBL and Vat Scarlet R) and anionic dyes (Reactive Violet K-3R and Acid Dark Blue 2G) were investigated in this study. The solution pH, presence of salt and surfactant can significantly affect the dye removal efficiency. The equilibrium data were analyzed using the Langmuir and Freundlich models. The Langmuir model is the most suitable to describe non-ionic dye adsorption, but for anionic dyes the Freundlich model is best. The kinetic data for the adsorption of different dyes were analyzed using pseudo first- and second-order equations, and the experimental data conformed to the pseudo second-order kinetic model better. The possibility of intraparticle diffusion was also examined by using the intraparticle diffusion equation. The single-stage batch adsorber design for the adsorption of both types of dyes onto EPI-DMA/bentonite was studied based on the Langmuir isotherm model for non-ionic dyes and the Freundlich isotherm model for anionic dyes. The results showed that the required amount of EPI-DMA/bentonite for 95% dye removal in 5 L dye solution with a concentration of 50 mg/L is 378.0 g for DB SBL, 126.5 g for VS R, 9.7 g for RV K-3R and 15.5 g for ADB 2G. PMID:20359811

Li, Qian; Yue, Qin-Yan; Sun, Hong-Jian; Su, Yuan; Gao, Bao-Yu

2010-07-01

302

Investigation on efficient adsorption of cationic dyes on porous magnetic polyacrylamide microspheres.  

PubMed

We report here the preparation of porous magnetic polyacrylamide microspheres for efficient removal of cationic dyes by a simple polymerization-induced phase separation method. Characterizations by various techniques indicate that the microspheres show porous structures and magnetic properties. They can adsorb methylene blue with high efficiency, with adsorption capacity increasing from 263 to 1977mg/g as the initial concentration increases from 5 to 300mg/L. Complete removal of methylene blue can be obtained even at very low concentrations. The equilibrium data is well described by the Langmuir isotherm models, exhibiting a maximum adsorption capacity of 1990mg/g. The adsorption capacity increases with increasing initial pH and reaches a maximum at pH 8, revealing an electrostatic interaction between the microspheres and the methylene blue molecules. The microspheres also show high adsorption capacities for neutral red and gentian violet of 1937 and 1850mg/g, respectively, as well as high efficiency in adsorption of mixed-dye solutions. The dye-adsorbed magnetic polyacrylamide microspheres can be easily desorbed, and can be repeatedly used for at least 6 cycles without losing the adsorption capacity. The adsorption capacity and efficiency of the microspheres are much higher than those of reported adsorbents, which exhibits potential practical application in removing cationic dyes. PMID:25797927

Yao, Tong; Guo, Song; Zeng, Changfeng; Wang, Chongqing; Zhang, Lixiong

2015-07-15

303

75 FR 12497 - Carbazole Violet Pigment 23 from India and the People's Republic of China: Final Results of the...  

Federal Register 2010, 2011, 2012, 2013, 2014

...A-570-892] Carbazole Violet Pigment 23 from India and the People's Republic of China...carbazole violet pigment 23 (CVP 23) from India and the People's Republic of China...antidumping duty orders on CVP 23 from India and the PRC\\1\\ pursuant to section...

2010-03-16

304

75 FR 29718 - Carbazole Violet Pigment 23 From India and the People's Republic of China: Continuation of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...A-570-892] Carbazole Violet Pigment 23 From India and the People's Republic of China...carbazole violet pigment 23 (CVP-23) from India and the People's Republic of China...antidumping duty orders on CVP-23 from India and the PRC \\1\\ pursuant to section...

2010-05-27

305

Blue-violet photoluminescence from amorphous Si-in-SiNx thin films with external quantum efficiency in percentages  

E-print Network

Blue-violet photoluminescence from amorphous Si-in-SiNx thin films with external quantum efficiency; published online 27 February 2006 Bright blue-violet photoluminescence centered at 428 nm was obtained.0% was measured in the as-deposited samples. Time-resolved photoluminescence spectra revealed decay times within

Zexian, Cao

306

The Chemistry of Plant and Animal Dyes.  

ERIC Educational Resources Information Center

Provides a brief history of natural dyes. Chemical formulas are provided for flavonoids, luteolin, genistein, brazilin, tannins, terpenes, naphthoquinone, anthraquinone, and dyes with an alkaloid structure. Also discusses chemical background of different dye processes. (CS)

Sequin-Frey, Margareta

1981-01-01

307

2nd International Symposium on Instrumentation Science and Technology Aug. 18~22, 2002, Jinan. China Stimulation of Violet Lasers to Traditional Chinese Medicine  

E-print Network

. China Stimulation of Violet Lasers to Traditional Chinese Medicine Photosensitizer for Diagnosis emission spectrum of the traditional Chinese medicine photosensitizer are measured, and two violet light exactly matches the absorption peak of the traditional Chinese medicine photosensitizer. Keywords: gastric

Bowers, John

308

Dye Sensitized Solar Cells  

PubMed Central

Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed. PMID:20480003

Wei, Di

2010-01-01

309

Gel Electrophoresis of Dyes  

NSDL National Science Digital Library

In this experiment related to plant biotechnology, learners discover how to prepare and load an electrophoresis gel. They will then run the gels in an electrophoresis system to separate several dyes that are of different molecular sizes and carry different charges. This technique is fundamental to many of the procedures used in biotechnology. This lesson guide includes background information for the educator, safety precautions, and questions with answers for learners. For safety reasons, adult supervision is recommended. Modifications for use with younger learners are described in a related PDF (see related resource).

Janice Stephens

2011-01-01

310

Photochemical damage to skin fibroblasts caused by protoporphyrin and violet light  

Microsoft Academic Search

Foreskin fibroblasts cultured in a medium containing protoporphyrin and exposed to violet light lose the capacity to proliferate. This phenomenon can be assessed on the basis of the ability of the irradiated cells to form colonies. Potentially lethal injuries can, however, be repaired during post-irradiation incubation under optimal growth conditions. We investigated the photodynamically induced transformations of certain molecular targets

A. A. Schothorst; C. A. C. De Haas; D. Suurmond

1980-01-01

311

21 CFR 74.1602 - D&C Violet No. 2.  

Code of Federal Regulations, 2010 CFR

...safe for use in color additive mixtures for coloring...be avoided by good manufacturing practice: Volatile...restrictions. The color additive D&C Violet No...consistent with good manufacturing practice. (d...label of the color additive and any mixtures...

2010-04-01

312

21 CFR 74.1602 - D&C Violet No. 2.  

Code of Federal Regulations, 2014 CFR

...safe for use in color additive mixtures for coloring...be avoided by good manufacturing practice: Volatile...restrictions. The color additive D&C Violet No...consistent with good manufacturing practice. (d...label of the color additive and any mixtures...

2014-04-01

313

21 CFR 74.1602 - D&C Violet No. 2.  

Code of Federal Regulations, 2012 CFR

...safe for use in color additive mixtures for coloring...be avoided by good manufacturing practice: Volatile...restrictions. The color additive D&C Violet No...consistent with good manufacturing practice. (d...label of the color additive and any mixtures...

2012-04-01

314

21 CFR 74.1602 - D&C Violet No. 2.  

Code of Federal Regulations, 2011 CFR

...safe for use in color additive mixtures for coloring...be avoided by good manufacturing practice: Volatile...restrictions. The color additive D&C Violet No...consistent with good manufacturing practice. (d...label of the color additive and any mixtures...

2011-04-01

315

21 CFR 74.1602 - D&C Violet No. 2.  

Code of Federal Regulations, 2013 CFR

...safe for use in color additive mixtures for coloring...be avoided by good manufacturing practice: Volatile...restrictions. The color additive D&C Violet No...consistent with good manufacturing practice. (d...label of the color additive and any mixtures...

2013-04-01

316

21 CFR 74.3602 - D&C Violet No. 2.  

Code of Federal Regulations, 2013 CFR

...color additive, D&C Violet No. 2, may be safely used for coloring absorbable meniscal tacks made from poly (L-lactic acid) at a level not to exceed 0.15 percent by weight of the tack material. (5) Authorization for these uses...

2013-04-01

317

21 CFR 500.30 - Gentian violet for animal drug use.  

Code of Federal Regulations, 2011 CFR

...and effective for any veterinary drug use in food animals and is a new animal drug subject to section 512 of the Federal Food, Drug, and...determined that gentian violet is not exempted from new animal drug status under the “grandfather”...

2011-04-01

318

21 CFR 500.30 - Gentian violet for animal drug use.  

Code of Federal Regulations, 2010 CFR

...and effective for any veterinary drug use in food animals and is a new animal drug subject to section 512 of the Federal Food, Drug, and...determined that gentian violet is not exempted from new animal drug status under the “grandfather”...

2010-04-01

319

21 CFR 500.30 - Gentian violet for animal drug use.  

Code of Federal Regulations, 2012 CFR

...and effective for any veterinary drug use in food animals and is a new animal drug subject to section 512 of the Federal Food, Drug, and...determined that gentian violet is not exempted from new animal drug status under the “grandfather”...

2012-04-01

320

21 CFR 500.30 - Gentian violet for animal drug use.  

Code of Federal Regulations, 2013 CFR

...and effective for any veterinary drug use in food animals and is a new animal drug subject to section 512 of the Federal Food, Drug, and...determined that gentian violet is not exempted from new animal drug status under the “grandfather”...

2013-04-01

321

21 CFR 500.30 - Gentian violet for animal drug use.  

Code of Federal Regulations, 2014 CFR

...and effective for any veterinary drug use in food animals and is a new animal drug subject to section 512 of the Federal Food, Drug, and...determined that gentian violet is not exempted from new animal drug status under the “grandfather”...

2014-04-01

322

Optical dephasing of cresyl violet in a polyvinyl alcohol polymer by non-photochemical hole burning  

NASA Astrophysics Data System (ADS)

A new burn—probe sequence is utilized with non-photochemical hole burning to study the optical dephasing of impurities in polymer films. For cresyl violet in polyvinyl alcohol the temperature dependence of dephasing is close to linear in the range studied. A burn time dependence of hole width is observed and discussed.

Carter, T. P.; Fearey, B. L.; Hayes, J. M.; Small, G. J.

1983-11-01

323

Monitoring the photobleaching of cresyl violet in polyvinyl alcohol using the photoacoustic effect  

NASA Astrophysics Data System (ADS)

Bleaching of cresyl violet in polyvinyl alcohol due to irradiation by a laser beam at three chopping frequencies is investigated using the photoacoustic technique. The results indicate that the bleaching rate decreases with increase in chopping frequency. This can be used as a potential medium for holographic recording and information storage.

Philip, Annieta; Radhakrishnan, P.; Nampoori, V. P.; Vallabhan, C. P.

1994-06-01

324

RECHERCHES SUR L'ABSORPTION DES RAYONS ULTRA-VIOLETS PAR DIVERSES SUBSTANCES;  

E-print Network

I45 RECHERCHES SUR L'ABSORPTION DES RAYONS ULTRA-VIOLETS PAR DIVERSES SUBSTANCES; PAR M. J travaux sur l'absorption de ces rayons. L'emploi du spectroscope à oculaire fluorescent que j'ai précé rayons invisibles. On sait que la partie directement visible du spectre comprend des radiations dont les

Boyer, Edmond

325

Children's School December 2013 Education Exchange in South Korea (Violet McGillen)  

E-print Network

Children's School December 2013 Education Exchange in South Korea (Violet McGillen) Mrs. Tomer and I spent a busy but enjoyable 9 days in Seoul, South Korea last month visiting Duksung Women divide between North and South Korea), the Korean Folk Village, which depicts Korea long ago, and we went

326

Differential inheritance of pepper (capsicum annum) fruit pigments results in black to violet fruit color  

Technology Transfer Automated Retrieval System (TEKTRAN)

Color and appearance of fruits and vegetables are critical determinants of product quality and may afford high-value market opportunities. Exploiting the rich genetic diversity in Capsicum, we characterized the inheritance of black and violet immature fruit color and chlorophyll, carotenoid and ant...

327

Decolorization Of Textile Dye Solutions  

Microsoft Academic Search

Results are presented on the use of ozone to decolorize textile dye solutions. The results describe the rates of reaction and the stoichiometry for the use of ozone to decolorize a simulated wastewater containing a bisazo acid dye (Acid Red 158). These rates of reaction are not sensitive to pH and are only mildly affected by temperature. The effects of

Julie Carrière; J. Peter Jones; Arthur D. Broadbent

1993-01-01

328

Hair Dyes and Cancer Risk  

MedlinePLUS

... Martinez A. Personal use of hair dyes and risk of cancer: a meta-analysis. JAMA: The Journal of the American Medical Association ... Buffler PA. Personal use of hair dyes and risk of bladder cancer: a meta-analysis of epidemiologic data. Cancer Causes and Control 2008; ...

329

Dye laser traveling wave amplifier  

NASA Technical Reports Server (NTRS)

A flash lamp pumped dye laser suitable for use as an amplifier stage was developed. The desired output laser pulses are of nanosecond duration, tunable in center frequency, and of good optical quality. Its usefulness as a laser oscillator is emphasized, because it constitutes a compact, relatively efficient source of tunable dye laser light.

Davidson, F.

1983-01-01

330

Studies of Solvent-Solute Interactions in the Photophysics of Laser Dyes.  

NASA Astrophysics Data System (ADS)

The fluorescence lifetime of rhodamine B in the normal alcohols (C_1-C_ {10}) and normal nitriles (C_2 ,C_5,C_6,C _8,C_9) has been measured using a picosecond laser system. The lifetime measuring technique is time-correlated single photon counting (TCSPC). Absorption and emission spectra of rhodamine B in the alcohols and nitriles have also been determined, thus allowing calculation of quantum yields, radiative, and nonradiative rates. The rotation of the dye's diethylamino groups is related to the nonradiative rate. A decreasing nonradiative rate corresponds to a greater energy barrier to rotation. The behavior of the nonradiative rates, and thus the rotational energy barrier, is modelled as a function of (1) solvent viscosity and (2) solvent polarity. The polarity-dependent model shows better correlation with the data. The nitrile data differs from the alcohol data in that the barrier appears to be constant and therefore independent of solvent viscosity and polarity. Hydrogen bonding is used to explain the differences between the alcohols and nitriles. Rotational relaxation times of two laser dyes (cresyl violet and oxazine-1) in polymer solution (poly(ethylene oxide) and methanol) has been measured using the transient absorption spectroscopy (TAS) method. TAS is a pump-probe technique using a picosecond laser system. The pump beam optically bleaches the sample and the probe beam monitors the transient response. The effect of increasing polymer concentration is seen as an increasing rotational relaxation time. This result is examined with respect to the Debye -Stokes-Einstein (DSE) equation governing viscosity-dependent, rotational reorientational times. The greater increase in the rotational times of cresyl violet is explained on the basis of increased polymer-dye interaction, specifically hydrogen bonding.

Casey, Kelly Gamble

331

Lyotropic Chromonic Liquid Crystals: Emerging Applications  

E-print Network

CHAPTER 14 Lyotropic Chromonic Liquid Crystals: Emerging Applications HEUNG-SHIK PARK and OLEG D interest in a distinct family of lyotropic liquid crystals (LCs), the so-called lyotropic chromonic liquid­7]. The range of materials which forms chromonic LC phases includes drugs [2, 3, 8­10], dyes [11­14], and DNA

Lavrentovich, Oleg D.

332

Albanian violets of the section Melanium, their morphological variability, genetic similarity and their adaptations to serpentine or chalk soils.  

PubMed

Violets of the section Melanium from Albanian serpentine and chalk soils were examined for their taxonomic affiliations, their ability to accumulate heavy metals and their colonization by arbuscular mycorrhizal fungi (AMF). The sequence analysis of the ITS1-5.8S rDNA-ITS2 region showed that all the sampled six Albanian violets grouped between Viola lutea and Viola arvensis, but not with Viola tricolor. The fine resolution of the ITS sequences was not sufficient for a further delimitation of the Albanian violets within the V. lutea-V. arvensis clade. Therefore, the Albanian violets were classified by a set of morphological characters. Viola albanica, Viola dukadjinica and Viola raunsiensis from serpentine soils as well as Viola aetolica from a chalk meadow were unambiguously identified, whereas the samples of Viola macedonica showed high morphological variability. All the violets, in both roots and shoots contained less than or similar levels of heavy metals as their harboring soils, indicating that they were heavy metal excluders. All the violets were strongly colonized by AMF with the remarkable exception of V. albanica. This violet lived as a scree creeper in shallow serpentine soil where the concentration of heavy metals was high but those of P, K and N were scarce. PMID:25462973

S?omka, Aneta; Godzik, Barbara; Szarek-?ukaszewska, Gra?yna; Shuka, Lulëzim; Hoef-Emden, Kerstin; Bothe, Hermann

2015-02-01

333

Soybean peroxidase-mediated degradation of an azo dye– a detailed mechanistic study  

PubMed Central

Background Peroxidases are emerging as an important class of enzymes that can be used for the efficient degradation of organic pollutants. However, detailed studies identifying the various intermediates produced and the mechanisms involved in the enzyme-mediated pollutant degradation are not widely published. Results In the present study, the enzymatic degradation of an azo dye (Crystal Ponceau 6R, CP6R) was studied using commercially available soybean peroxidase (SBP) enzyme. Several operational parameters affecting the enzymatic degradation of dye were evaluated and optimized, such as initial dye concentration, H2O2 dosage, mediator amount and pH of the solution. Under optimized conditions, 40 ppm dye solution could be completely degraded in under one minute by SBP in the presence of H2O2 and a redox mediator. Dye degradation was also confirmed using HPLC and TOC analyses, which showed that most of the dye was being mineralized to CO2 in the process. Conclusions Detailed analysis of metabolites, based on LC/MS results, showed that the enzyme-based degradation of the CP6R dye proceeded in two different reaction pathways- via symmetric azo bond cleavage as well as asymmetric azo bond breakage in the dye molecule. In addition, various critical transformative and oxidative steps such as deamination, desulfonation, keto-oxidation are explained on an electronic level. Furthermore, LC/MS/MS analyses confirmed that the end products in both pathways were small chain aliphatic carboxylic acids. PMID:24308857

2013-01-01

334

Large Assembly Formation via a Two-Step Process in a Chromonic Liquid Crystal  

E-print Network

of Pennsylvania, Philadelphia, Pennsylvania 19014, United States ABSTRACT: IR-806 is a near-infrared cyanine dye at concentrations as low as 0.5 wt %. Unlike many chromonic liquid crystals, the absorption spectrum of IR- 806 liquid crystals spontaneously assemble, a process ubiquitous in living systems. Since dyes, drugs

Collings, Peter

335

Dye-sensitized solar cells  

DOEpatents

A low-cost dye-sensitized Schottky barrier solar cell is comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent. 3 figs.

Skotheim, T.A.

1980-03-04

336

Dye-sensitized solar cells  

DOEpatents

A low-cost dye-sensitized Schottky barrier solar cell comprised of a substrate of semiconductor with an ohmic contact on one face, a sensitizing dye adsorbed onto the opposite face of the semiconductor, a transparent thin-film layer of a reducing agent over the dye, and a thin-film layer of metal over the reducing agent. The ohmic contact and metal layer constitute electrodes for connection to an external circuit and one or the other or both are made transparent to permit light to penetrate to the dye and be absorbed therein for generating electric current. The semiconductor material chosen to be the substrate is one having a wide bandgap and which therefore is transparent; the dye selected is one having a ground state within the bandgap of the semiconductor to generate carriers in the semiconductor, and a first excited state above the conduction band edge of the semiconductor to readily conduct electrons from the dye to the semiconductor; the reducing agent selected is one having a ground state above the ground state of the sensitizer to provide a plentiful source of electrons to the dye during current generation and thereby enhance the generation; and the metal for the thin-film layer of metal is selected to have a Fermi level in the vicinity of or above the ground state of the reducing agent to thereby amply supply electrons to the reducing agent.

Skotheim, Terje A. [Berkeley, CA

1980-03-04

337

Liquid Crystals Tunable Optical Metamaterials  

Microsoft Academic Search

A critical discussion with detailed calculations for the complex refractive indexes of metamaterials of various nanoconstituent makeups, sizes, shapes and concentrations, and periodic nanostructured patterns\\/geometry are presented. These metamaterials possess tunable subunity, zero, or negative refractive indexes, on account of the large birefringence of their nematic liquid crystal constituent. We also studied the special case involving laser dye-doped nematic liquid

Iam Choon Khoo; Andres Diaz; Justin Liou; Michael V. Stinger; Junbin Huang; Yi Ma

2010-01-01

338

Dielectric and thermal effects on the optical properties of natural dyes: a case study on solvated cyanin.  

PubMed

The optical properties of the flavylium state of the cyanin dye are simulated numerically by combining Car-Parrinello molecular dynamics and linear-response time-dependent density functional theory calculations. The spectrum of the dye calculated in the gas phase is characterized by two peaks in the yellow and in the blue (green and violet), using a GGA-PBE (hybrid-B3LYP) DFT functional, which would bring about a greenish (bright orange) color incompatible with the dark purple hue observed in nature. Describing the effect of the water solvent through a polarizable continuum model does not modify qualitatively the resulting picture. An explicit simulation of both solvent and thermal effects using ab initio molecular dynamics results instead in a spectrum that is compatible with the observed coloration. This result is analyzed in terms of the spectroscopic effects of the molecular distortions induced by thermal fluctuations. PMID:21905678

Malc?o?lu, Osman Bari?; Calzolari, Arrigo; Gebauer, Ralph; Varsano, Daniele; Baroni, Stefano

2011-10-01

339

Never say dye  

PubMed Central

Recent years have seen a remarkable increase in the number of publications dealing with the application of epifluorescence microscopy in cell biology. This can be widely attributed to the development of state-of-the-art image processing programs, as well as the development of new reagents/probes, which allow the labeling of most cell structures, organelles and metabolites with high specificity. However, the use of a specific fluorescent dye, 3,3?-dihexyloxacarbocyanine iodide (DiOC6), has been recently revisited and several new application potentials have emerged. The goal of this mini-review is to provide an up-to-date overview of the multiple roles of this multifaceted probe. PMID:22476459

2012-01-01

340

Dyeing Properties of Natural Dye Syzygium cuminii on Silk  

NASA Astrophysics Data System (ADS)

Dyeing behavior of natural dye extracted from the bark of Syzygium cuminii L has been studied on silk fabric. Colour values and colour co-ordinates were examined in terms of K/S and L* a* b* C and h. A range of shades were obtained by using various mordants and mordanting techniques. Dye was tested for some of the eco-parameters using atomic absorption spectrophotometry and GC/MS. The test results were compared with the set standards to determine the eco-friendliness of natural dye. Their concentrations were much below the stipulated limits. Dyed samples were tested for antimicrobial activity against Gram-positive and Gram-negative bacteria and were found to possess antibacterial activity.

Narayana Swamy, V.; Ninge Gowda, K. N.; Sudhakar, R.

2014-04-01

341

Interaction between lyotropic chromonic liquid crystals and polymers  

Microsoft Academic Search

Lyotropic chromonic liquid crystals (LCLCs) consist of various dyes, drugs, etc., so their importance is self-evident. The interaction of chromonic molecules and polymers is involved in their real applications, such as the dyeing process of fibers, textiles and food, and the functionalization of drugs in vivo. In our research, polymer dispersed LCLC droplets and polymer coated LCLC cells have been

Xuxia Yao; Jung Park; Mohan Srinivasarao

2010-01-01

342

Enhancing cholesteric liquid crystal laser performance using a cholesteric reflector  

E-print Network

and lasing in dye-doped polymer cholesteric liquid crystal," Jpn. J. Appl. Phys. 43, 6142-6144 (2004). 10. HEnhancing cholesteric liquid crystal laser performance using a cholesteric reflector Ying Zhou-doped cholesteric liquid crystal (CLC) laser is demonstrated by incorporating a passive CLC reflector to the active

Wu, Shin-Tson

343

Oriented Monolayers Prepared from Lyotropic Chromonic Liquid Crystal  

E-print Network

Oriented Monolayers Prepared from Lyotropic Chromonic Liquid Crystal Tod Schneider, Kateryna from lyotropic chromonic liquid crystals (LCLCs) on mica substrates. The aqueous solutions of dye used layer-by-layer through electrostatic deposition from the so-called lyotropic chromonic liquid crystal

Lavrentovich, Oleg D.

344

Trend towards low cost, low power, ultra-violet (UV) based biological agent detectors  

NASA Astrophysics Data System (ADS)

Ultra-violet fluorescence remains a corner stone technique for the detection of biological agent aerosols. Historically, these UV based detectors have employed relatively costly and power demanding lasers that have influenced the exploitation of the technology to wider use. Recent advancements from the Defense Advanced Research Project Agency's (DARPA) Solid-state Ultra Violet Optical Sources (SUVOS) program has changed this. The UV light emitting diode (LED) devices based on Gallium Nitride offer a unique opportunity to produce small, low power, and inexpensive detectors. It may, in fact, be possible to extend the SUVOS technology into detectors that are potentially disposable. This report will present ongoing efforts to explore this possibility. It will present candidate UV fluorescence based detector designs along with the biological aerosol responses obtained from these designs.

Sickenberger, David

2005-11-01

345

Sixteen new IR laser dyes  

Microsoft Academic Search

Sixteen new IR laser dyes are reported. All lased successfully under excitation from a simple linear flashlamp of about 700-ns rise time. Untuned lasing wavelengths ranged from 810 to 972 nm. Laser output pulse energies from the four best of these dyes were 5-15 times greater than from diethylthiatricarbocyanine iodide (DTTC), with peak output of about 50 mJ obtained from

J. P. Webb; F. G. Webster; B. E. Plourde

1975-01-01

346

Development of an ultra-violet digital camera for volcanic SO2 imaging  

Microsoft Academic Search

In an effort to improve monitoring of passive volcano degassing, we have constructed and tested a digital camera for quantifying the sulfur dioxide (SO2) content of volcanic plumes. The camera utilizes a bandpass filter to collect photons in the ultra-violet (UV) region where SO2 selectively absorbs UV light. SO2 is quantified by imaging calibration cells of known SO2 concentrations. Images

G. J. S. Bluth; J. M. Shannon; I. M. Watson; A. J. Prata; V. J. Realmuto

2007-01-01

347

ELISPOT Analysis of Pulmonary and Systemic Cytokines in Ultra-Violet Attenuated Cercariae Vaccine Model  

Microsoft Academic Search

We have previously demonstrated that vaccination of mice with ultra-violet (uv) attenuated cercariae of Schismornu rnunsoni induces significant level of cell mediated immunity. Other in vivo and in vitro studies in similar vaccine models have demonstrated the predominance of the T he1 er-I (Thl) cytokine responses mainly interferon-gamma (IFN-y) in pulmonary immune mechanisms. he current study extends this analysis to

Abdel Ghaffar AB; Borai IH; Phillips SM

348

Possible detection of violet-shifted absorption and emission lines from HBV 475  

NASA Astrophysics Data System (ADS)

High-dispersion spectra of HBV 475 were obtained. In the spectrum taken in November, 1981 three possible absorption lines of Fe I and three emission lines of [Fe II] are detected. These absorption and emission lines are both shifted to the violet side by about 10 Å. However, in November, 1982 these lines disappeared. The appearance of these lines may suggest an explosive phenomenon in this object through its inhomogeneous chromosphere.

Tamura, S.

349

RESONANCE LIGHT SCATTERING FOR THE DETERMINATION OF NUCLEIC ACIDS WITH METHYL VIOLET  

Microsoft Academic Search

For the first time, methyl violet (MV) was used to determine nucleic acids with a resonance light scattering (RLS) technique. The interactions of MV with nucleic acids give strong signals of RLS at 327.0, 490.0 and 651.0 nm. Based on this reaction, a new quantitative determination method for nucleic acids in aqueous solutions has been developed. At pH 7.51 and

Wu Juan Zhang; Hong Ping Xu; Chun Xia Xue; Xing Guo Chen; Zhi De Hu

2001-01-01

350

Luminescence degradation of InGaN\\/GaN violet LEDs  

Microsoft Academic Search

The changes of optical output power and electrical property of InGaN\\/GaN violet light-emitting diodes (LEDs) with different indium compositions have been investigated, under injection current densities of 26.5 and 79.5A\\/cm2. When injection current density was 26.5A\\/cm2, output power of LEDs with low indium composition (2%) degraded more rapidly than the ones of 10% indium inside. At a large injection level

Tongjun Yu; Shuping Shang; Zhizhong Chen; Zhixin Qin; Liang Lin; Zhijian Yang; Guoyi Zhang

2007-01-01

351

Dye molecules in electrolytes: new approach for suppression of dye-desorption in dye-sensitized solar cells  

PubMed Central

The widespread commercialization of dye-sensitized solar cells remains limited because of the poor long-term stability. We report on the influence of dye-molecules added in liquid electrolyte on long-term stability of dye-sensitized solar cells. Dye-desorption from the TiO2 surface during long-term cycling is one of the decisive factors that degrade photocurrent densities of devices which in turn determine the efficiencies of the devices. For the first time, desorption of dye from the TiO2 surface could be suppressed by controlling thermodynamic equilibrium; by addition of dye molecules in the electrolyte. The dye molecules in the electrolyte can suppress the driving forces for the adsorbed dye molecules to be desorbed from TiO2 nanoparticles. As a result, highly enhanced device stabilities were achieved due to the reduction of dye-desorption although there was a little decrease in the initial efficiencies.

Heo, Nansra; Jun, Yongseok; Park, Jong Hyeok

2013-01-01

352

Nanoporous membranes with cellulose nanocrystals as functional entity in chitosan: removal of dyes from water.  

PubMed

Fully biobased composite membranes for water purification were fabricated with cellulose nanocrystals (CNCs) as functional entities in chitosan matrix via freeze-drying process followed by compacting. The chitosan (10 wt%) bound the CNCs in a stable and nanoporous membrane structure with thickness of 250-270 ?m, which was further stabilized by cross-linking with gluteraldehyde vapors. Scanning electron microscopy (SEM) studies revealed well-individualized CNCs embedded in a matrix of chitosan. Brunauer, Emmett and Teller (BET) measurements showed that the membranes were nanoporous with pores in the range of 13-10nm. In spite of the low water flux (64 Lm(-2) h(-1)), the membranes successfully removed 98%, 84% and 70% respectively of positively charged dyes like Victoria Blue 2B, Methyl Violet 2B and Rhodamine 6G, after a contact time of 24h. The removal of dyes was expected to be driven by the electrostatic attraction between negatively charged CNCs and the positively charged dyes. PMID:25129796

Karim, Zoheb; Mathew, Aji P; Grahn, Mattias; Mouzon, Johanne; Oksman, Kristiina

2014-11-01

353

A violet emission in ZnS:Mn,Eu: Luminescence and applications for radiation detection  

SciTech Connect

We prepared manganese and europium co-doped zinc sulfide (ZnS:Mn,Eu) phosphors and used them for radiation detection. In addition to the red fluorescence at 583?nm due to the d-d transition of Mn ions, an intense violet emission at 420?nm is newly observed in ZnS:Mn,Eu phosphors. The emission is related to Eu{sup 2+} doping but only appears at certain Eu{sup 2+} concentrations. It is found that the intensity of the 420?nm violet fluorescence is X-ray does-dependent, while the red fluorescence of 583?nm is not. The ratio of fluorescence intensities at 420?nm and 583?nm has been monitored as a function of X-ray doses that exposed upon the ZnS:Mn,Eu phosphors. Empirical formulas are provided to estimate the doses of applied X-ray irradiation. Finally, possible mechanisms of X-ray irradiation induced fluorescence quenching are discussed. The intense 420?nm emission not only provides a violet light for solid state lighting but also offers a very sensitive method for radiation detection.

Ma, Lun; Chen, Wei, E-mail: weichen@uta.edu [Department of Physics and the SAVANT Center, The University of Texas at Arlington, Arlington, Texas 76019-0059 (United States); Jiang, Ke [Center for Biofrontiers Institute, University of Colorado at Colorado Springs, 1420 Austin Bluffs Pkwy., Colorado Springs, Colorado 80918 (United States); Liu, Xiao-tang [Department of Physics and the SAVANT Center, The University of Texas at Arlington, Arlington, Texas 76019-0059 (United States); Department of Applied Chemistry, College of Science, South China Agricultural University, Guangzhou 510642 (China)

2014-03-14

354

Micro-mold fabrication by PET anisotropic ultra-violet assisted etching suitable for 3D structures on Si  

Microsoft Academic Search

Ultra-violet assisted vertical etching of PET polymers has been successfully exploited for the realization of micro-molds on silicon substrates. Vertical etching of PET substrate with an aspect ratio of 10:1 has been achieved, using DMF as a strong solvent in the presence of ultra-violet illumination. Etch rates as high as 80?m\\/h are obtained at a substrate temperature of 120°C and

S. Famini; B. Fallah; M. Sadeghi; M. Araghchini; S. Mohajerzadeh; M. Abdolhamidi; B. Sadeghi

2005-01-01

355

Production of laccase and manganese peroxidase by Pleurotus pulmonarius in solid-state cultures and application in dye decolorization.  

PubMed

The production of ligninolytic enzymes (laccase and Mn-dependent peroxidase) by the white-rot fungus Pleurotus pulmonarius (FR.) Quélet was studied in solid-state cultures using agricultural and food wastes as substrate. The highest activities of laccase were found in wheat bran (2,860?±?250 U/L), pineapple peel (2,450?±?230 U/L), and orange bagasse (2,100?±?270 U/L) cultures, all of them at an initial moisture level of 85 %. The highest activities of Mn peroxidase were obtained in pineapple peel cultures (2,200?±?205 U/L) at an initial moisture level of 75 %. In general, the condition of high initial moisture level (80-90 %) was the best condition for laccase activity, while the best condition for Mn peroxidase activity was cultivation at low initial moisture (50-70 %). Cultures containing high Mn peroxidase activities were more efficient in the decolorization of the industrial dyes remazol brilliant blue R (RBBR), Congo red, methylene blue, and ethyl violet than those containing high laccase activity. Also, crude enzymatic extracts with high Mn peroxidase activity were more efficient in the in vitro decolorization of methylene blue, ethyl violet, and Congo red. The dye RBBR was efficiently decolorized by both crude extracts, rich in Mn peroxidase activity or rich in laccase activity. PMID:23645502

dos Santos Bazanella, Gisele Cristina; de Souza, Daniela Farani; Castoldi, Rafael; Oliveira, Roselene Ferreira; Bracht, Adelar; Peralta, Rosane Marina

2013-11-01

356

Dye laser amplifier including a dye cell contained within a support vessel  

DOEpatents

A large (high flow rate) dye laser amplifier in which a continous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of greater than 30 gallons/minute at a static pressure greater than 150 pounds/square inch and a specifically designed support vessel for containing the dye cell.

Davin, James (Gilroy, CA)

1992-01-01

357

Dye laser amplifier including a dye cell contained within a support vessel  

DOEpatents

A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of greater than 30 gallons/minute at a static pressure greater than 150 pounds/square inch and a specifically designed support vessel for containing the dye cell. 6 figs.

Davin, J.

1992-12-01

358

Dye laser solutions  

SciTech Connect

This patent describes a composition of matter, a cyclodextrin inclusion compound of a fluorescent dye and an {alpha}- or {beta}-chclodextrin having a substituent bonded to an oxygen atom in a glucose unit in the cyclodextrin. The substituent is selected from the class consisting of: alkyl radicals having 1 to 6 carbon atoms, radicals having the formula {bond}CH{bond}CHR{sup 1}{bond}O{sub {ital n}}H wherein R{sup 1} is selected from hydrogen and alkyl radicals having up to about six carbon atoms, and n is equal to a small whole number up to six, and radicals having the formula {bond}CHR{sup 1}{bond}CHOH{bond}CHR{sup 1}{bond} wherein R{sup 1} has the same definition as above, such that the radicals bridge two cyclodextrin rings, and the number of the rings so bridged per molecule is from two to about six; the substituted cyclodextrin having not ore than two substituents per glucose unit.

Herkstroeter, W.G.

1990-06-12

359

Effect of nitrate on anaerobic azo dye reduction.  

PubMed

The aim of the study was to investigate the effect of nitrate on anaerobic color removal efficiencies. For this aim, anaerobic-aerobic sequencing batch reactor (SBR) fed with a simulated textile effluent including Remazol Brilliant Violet 5R azo dye was operated with a total cycle time of 12 h, including anaerobic (6 h) and aerobic cycles (6 h). Microorganism grown under anaerobic phase of the reactor was exposed to different amounts of competitive electron acceptor (nitrate) and performance of the system was determined by monitoring color removal efficiency, nitrate removal, nitrite formation and removal, oxidation reduction potential, color removal rate, chemical oxygen demand (COD), specific anaerobic enzyme (azo reductase) and aerobic enzyme (catechol 1,2 dioxygenase), and formation and removal of aromatic amines. Variations of population dynamics of microorganisms exposed to various amount of nitrate were identified by denaturing gradient gel electrophoresis (DGGE). It was found that nitrate has adverse effect on anaerobic color removal efficiency and color removal was achieved after denitrification process was completed. It was found that nitrate stimulates the COD removal efficiency and accelerates the COD removal in the first hour of anaerobic phase. About 90 % total COD removal efficiencies were achieved in which microorganism exposed to increasing amount of nitrate. Population dynamics of microorganisms exposed to various amount of nitrate were changed and diversity was increased. PMID:22836282

Cirik, Kevser; Kiti?, Mehmet; Çinar, Özer

2013-01-01

360

Preparation of nano-sized mixed crystal TiO2-coated Er3+:YAlO3 by sol-gel method for photocatalytic degradation of organic dyes under visible light irradiation.  

PubMed

In this work, an upconversion luminescence agent, crystallized Er(3 + ):YAlO(3), was synthesized and then coated by the nano-sized TiO(2) film through sol-gel technique. A novel TiO(2) photocatalyst, Er(3 + ):YAlO(3)/TiO(2), with high activity in visible light was subsequently prepared. The Er(3 + ):YAlO(3) and Er(3 + ):YAlO(3)/TiO(2) were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM). The photocatalytic activity of Er(3 + ):YAlO(3)/TiO(2) photocatalyst was tested by the degradation of acid red B in aqueous solution as the primary model compound under visible light irradiation. The experimental results proved that the prepared TiO(2)-coated crystallized Er(3 + ):YAlO(3) was able to decompose the acid red B efficiently, and it is promising to use the idea to develop new TiO(2) photocatalyst with high activity for photocatalytic degradation under visible light. PMID:19700830

Wang, Jun; Li, Jia; Liu, Bin; Xie, Yingpeng; Han, Guangxi; Li, Ying; Zhang, Liqun; Zhang, Xiangdong

2009-01-01

361

Sea dye marker provides visibility for 20 hours  

NASA Technical Reports Server (NTRS)

Sea dye marker block releases a visible slick which lasts at least twelve hours. The dye marker uses a fluorescent dye in a heat cured binder which, when immersed in seawater, releases the dye at a controlled rate.

De Laat, F.

1966-01-01

362

Dyes as tracers for vadose zone hydrology  

NASA Astrophysics Data System (ADS)

Dyes are important tracers to investigate subsurface water movement. For more than a century, dye tracers have provided clues about the hydrological cycle as well as flow and transport processes in the subsurface. Groundwater contamination often originates in the vadose zone. Agrochemicals applied to the soil surface, toxic compounds accidentally spilled by human activities, and contaminants released from waste repositories leach through the vadose zone and can ultimately pollute groundwater resources. Dyes are an important tool to assess flow pathways of such contaminants. This review compiles information on dyes used as hydrological tracers, with particular emphasis on vadose zone hydrology. We summarize briefly different human-applied tracers, including nondye tracers. We then provide a historical sketch of the use of dyes as tracers and describe newer developments in visualization and quantification of tracer experiments. Relevant chemical properties of dyes used as tracers are discussed and illustrated with dye intermediates and selected dye tracers. The types of dyes used as tracers in subsurface hydrology are summarized, and recommendations are made regarding the use of dye tracers. The review concludes with a toxicological assessment of dyes used as hydrological tracers. Many different dyes have been proposed as tracers for water movement in the subsurface. All of these compounds, however, are to some degree retarded by the subsurface medium. Nevertheless, dyes are useful tracers to visualize flow pathways.

Flury, Markus; Wai, Nu Nu

2003-03-01

363

Growth of GaN single crystals by a Ca and Ba-added Na flux method  

Microsoft Academic Search

GaN substrates are desirable for fabricating ultra-violet LEDs and LDs, and high-power and high-frequency transistors. High-quality GaN single crystals can be obtained by using Na flux method, but the growth habit of bulk crystals must be controlled. In this study, we investigated the effects of additives (Ca, Ba) on the growth habit and impurity concentration in the crystals. The aspect

H. Ukegawa; Y. Konishi; T. Fujimori; N. Miyoshi; M. Imade; M. Yoshimura; Y. Kitaoka; T. Sasaki; Y. Mori

2011-01-01

364

Rotational reorientation dynamics of polar dye molecular probes by picosecond laser spectroscopic technique  

NASA Astrophysics Data System (ADS)

Fluorescence lifetimes and rotational reorientation times for four structurally similar dye molecules—three monocations: cresyl violet, nile blue, and oxazine 720 and one neutral but polar: nile red—have been measured by picosecond time-resolved fluorescence depolarization spectroscopy using the single-photon counting technique, in a number of solvents, which included a wide range of alcohols, other hydrogen-bonding liquids, and a few aprotic liquids. The rotational reorientation of the dye probes (assumed to be oblate ellipsoids) are sought to be explained in terms of the Stokes-Einstein-Debye theory and dielectric friction. The individual contributions to the rotational friction due to the above two factors were calculated using reasonable values for the molecular volume and dipole moment of the solute. The rotational behavior of all the four dyes in amides and aprotic solvents is reasonably well explained in terms of the simple stick hydrodynamic model with the ``molecular volume'' obtained by using the measured rotational reorientation time in water. On the other hand, in order to describe the rotational reorientation dynamics of all the dye molecules in n-alcohols, it is necessary to include the friction contribution due to the dielectric properties of the solvent. It appears that a change in boundary condition, something intermediate between stick and slip or close to slip, is required to satisfactorily explain the rotational reorientation times of the dye molecules in polyalcohols like ethylene glycol and glycerol. Investigation of the rotational behavior of all the four dyes as a function of viscosity by varying the temperature has been carried out in three solvents: 1-heptanol, 1-undecanol, and ethylene glycol. While the rotational reorientation times had a good linear ?/T dependence, it was found that at a particular macroscopic viscosity value the rotational reorientation times obtained by the solvent variation and temperature variation are different. From the temperature variation study it was found that there is a satisfactory agreement between the solvent viscosity activation energy and the activation energy obtained for the reorientation rate of the dye probe molecules.

Dutt, G. B.; Doraiswamy, S.; Periasamy, N.; Venkataraman, B.

1990-12-01

365

Ultrafast Phenomena in Organic Dyes, Semiconductor Microcrystals, and Superconductors.  

NASA Astrophysics Data System (ADS)

This dissertation covers a small part of the vast field of "Ultrafast Phenomena", e.g. phase relaxation, which represents the very first and one of the most fundamental steps in light-matter interaction. In particular, we have adopted approaches somewhat different from the commonly used ones, which have proven to be as applicable and sometimes even superior in many ways. Based on the fact that in correlation-type experiments the temporal resolution is determined by the correlation time (tau_{rm c}) of the electric field of the laser pulses, rather than the pulse duration, we have taken advantage of a broadband amplified spontaneous emission (ASE) from a nitrogen laser -pumped dye oscillator-amplifier system and achieved a resolution as good as 40fs. Various organic dyes, Rhodamine 560, 575, 590, 640 and Cresyl Violet 670 have been studied systematically. Besides the observations of different phase relaxation behaviors for different dye molecules, interesting molecular vibrations in Rhodamine 560 and 575 have also been observed. In addition, we have measured the T_2 of semiconductor microcrystals in a few semiconductor doped glasses (SDG), Hoya Y-52, O-54 and O-56, which are unique in many ways. The temperature dependence of T_2 has been studied in detail and it has been concluded that phonon scattering and absorption are the dominant mechanisms for the temperature-dependence of the exciton phase relaxation. The optical response of high T_ {rm c} superconducting rm Y_1Ba_2Cu_3O_7 thin films has been investigated using a novel autocorrelation -like double-bridge technique, which eliminates the need for a fast oscilloscope, and the temporal resolution is limited only by the duration of the excitation pulses. This study examines the voltage pulses generated in current -biase thin films by short laser pulse excitation and their dependence on laser fluence, bias current, temperature, and especially film thickness. Voltage pulses as short as 40ps, one of the fastest reported so far, have been observed. It has been concluded that phonon escaping is the bottleneck process in the relaxation of the nonequilibrium system of quasiparticles and phonons.

Huang, Guolin

366

FATE OF COMMERCIAL DISPERSE DYES IN SEDIMENTS  

EPA Science Inventory

Kinetics of disappearance of seven different disperse dyes were determined in compacted sediments at room temperature. he commercial dyes (in dispersed solid form) were representative of nitroazo, anthraquinone, and quinoline structures that are widely used. eaction rates were fo...

367

Single mode pulsed dye laser oscillator  

DOEpatents

A single mode pulsed dye laser oscillator is disclosed. The dye laser oscillator provides for improved power efficiency by reducing the physical dimensions of the overall laser cavity, which improves frequency selection capability. 6 figs.

Hackel, R.P.

1992-11-24

368

Anaerobic\\/aerobic treatment of selected azo dyes in wastewater  

Microsoft Academic Search

Azo dyes represent the largest class of dyes in use today. Current environmental concern with these dyes revolves around the potential carcinogenic health risk presented by these dyes or their intermediate biodegradation products when exposed to microflora in the human digestive tract. These dyes may build up in the environment, since many wastewater treatment plants allow these dyes to pass

S. Seshadri; P. L. Bishop; A. M. Agha

1994-01-01

369

Synthesis and characterization of some perylene dyes for dye-based LCD color filters  

Microsoft Academic Search

Eight red perylene dyes were synthesized to improve the optical performance of LCD color filters. Among them, dyes with bulky functional substituents at the bay and terminal positions were highly soluble in cyclohexanone, the industrial solvent currently used in the pigment dispersion method. The spectral properties and thermal stability of the dye-based color filters with these dyes were examined by

Jun Choi; Chun Sakong; Jae-Hong Choi; Chun Yoon; Jae Pil Kim

2011-01-01

370

Self-Assembled Monolayers and Multilayered Stacks of Lyotropic Chromonic Liquid Crystalline Dyes with  

E-print Network

Self-Assembled Monolayers and Multilayered Stacks of Lyotropic Chromonic Liquid Crystalline Dyes and a lyotropic chromonic (nonamphiphilic) liquid crystal, which allows one to orient the molecules uniformly in the plane of deposition. The long-range in-plane orientation of the chromonic molecules determines

Lavrentovich, Oleg D.

371

High contrast switching of distributed-feedback lasing in dye-doped H-PDLC transmission  

E-print Network

structures Vincent K.S. Hsiao, Changgui Lu, Guang S. He, Michael Pan, Alexander N. Cartwright and Paras N is presented in a Pyrromethene 580 lasing dye-doped holographic polymer dispersed liquid crystal (H-PDLC) transmission grating structure. This design, when compared with the previously utilized H-PDLC reflection

Cartwright, Alexander N.

372

Reactive dye biosorption by Rhizopus arrhizus biomass  

Microsoft Academic Search

The biosorption of three commonly used reactive dyes, from aqueous solutions by oven-dried Rhizopus arrhizus biomass was studied in a batch system with respect to pH, initial dye concentration and initial metal ion concentration. The biomass exhibited maximum dye uptake at pH 2 due to its positively charged nature at acidic pH and the anionic nature of the reactive dyes.

T O’Mahony; E Guibal; J. M Tobin

2002-01-01

373

Dye laser amplifier including a low turbulence, stagnation-free dye flow configuration  

DOEpatents

A large (high flow rate) dye laser amplifier in which a continuous replenished supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a flow rate of for example 30 gallons/minute, a specifically designed support vessel for containing the dye cell and a screen device for insuring that the dye stream passes into the dye cell in a substantially turbulent free, stagnation-free manner. 9 figs.

Davin, J.

1992-12-01

374

Jupiter's Belt-Zone Boundary in Near-Infrared and Violet Light  

NASA Technical Reports Server (NTRS)

Mosaics of a belt-zone boundary near Jupiter's equator in violet (top panel) and near-infrared (bottom panel) light. The four images that make up each of these mosaics were taken within a few minutes of each other. Sunlight at 757 nanometers (near-infrared) penetrates deep into Jupiter's troposphere before being absorbed or scattered by clouds to the Galileo spacecraft. This wavelength reveals the features of the lower visible cloud deck. Sunlight at 415 nanometers (violet) is a scattered or absorbed to varying degrees in different parts of Jupiter's atmosphere depending on the types and concentrations of cloud particles and chemicals that color Jupiter's atmosphere. The near-infrared mosaic primarily shows cloud features. The violet mosaic has three distinct regions: it is brightest at the latitude of the jet (horizontally across the center of the mosaic), moderately bright north of the jet, and dark and patchy south of the jet.

North is at the top. The mosaic covers latitudes -13 to +3 degrees and is centered at longitude 282 degrees West. The smallest resolved features are tens of kilometers in size. These images were taken on November 5th, 1996, at a range of 1.2 million kilometers by the Solid State Imaging system aboard NASA's Galileo spacecraft.

The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

1997-01-01

375

Treatment of Helicobacter pylori Infection with Intra-Gastric Violet Light Phototherapy – a Pilot Clinical Trial  

PubMed Central

Background and Objective Helicobacter pylori infects the mucus layer of the human stomach and causes peptic ulcers and adenocarcinoma. We have previously shown that H. pylori accumulates photoactive porphyrins making the organism susceptible to inactivation by light, and that small spot endoscopic illumination with violet light reduced bacterial load in human stomachs. This study assessed the feasibility and safety of whole-stomach intra-gastric violet phototherapy for the treatment of H. pylori infection. Study Design/Materials and Methods A controlled, prospective pilot trial was conducted using a novel light source consisting of laser diodes and diffusing fibers to deliver 408-nm illumination at escalating total fluences to the whole stomach. Eighteen adults (10 female) with H. pylori infection were treated at 3 U.S. academic endoscopy centers. Quantitative bacterial counts were obtained from biopsies taken from the antrum, body and fundus, and serial urea breath tests. Results The largest reduction in bacterial load was in the antrum (>97%), followed by body (>95%) and fundus (>86%). There was a correlation between log reduction and initial bacterial load in the antrum. There was no dose-response seen with increasing illumination times. The urea breath test results indicated that the bacteria repopulated in days following illumination. Conclusion Intragastric violet light phototherapy is feasible and safe and may represent a novel approach to eradication of H. pylori, particularly in patients who have failed standard antibiotic treatment. This was a pilot study involving a small number of patients. Further research is needed to determine if phototherapy can be effective for eradicating H. pylori. PMID:19533762

Lembo, Anthony J; Ganz, Robert A; Sheth, Sunil; Cave, David; Kelly, Ciaran; Levin, Philip; Kazlas, Peter T; Baldwin, Paul C; Lindmark, William R; McGrath, Jonathan R; Hamblin, Michael R

2009-01-01

376

Tracking antigen-driven responses by flow cytometry: monitoring proliferation by dye dilution.  

PubMed

Cell-tracking reagents such as the green-fluorescent protein labeling dye CFSE and the red-fluorescent lipophilic membrane dye PKH26 are commonly used to monitor cell proliferation by flow cytometry in heterogeneous cell populations responding to immune stimuli. Both reagents stain cells with a bright homogeneous fluorescence, which is partitioned between daughter cells during each cell division. Because daughter cell fluorescence intensities are approximately halved after each division, the intensity of a cell relative to its intensity at the time of staining provides information about how many divisions it has undergone. Knowing how many rounds of division have occurred and the relative number of cells in each daughter generation, one can back-calculate the number of cells in the original population (i.e., cells present at the time of stimulus) that went on to respond by proliferating. Using this information, the precursor cell frequencies and extent of expansion to a specific antigen or mitogen of interest can be calculated. Concurrently, the phenotype of the cells can be determined, as well as their ability to bind antigen or synthesize cytokines, providing more detailed characterization of all cells responding to the antigen, not just effector cells. In multiparameter flow cytometric experiments to simultaneously analyze antigen-specific tetramer binding, cytokine production and T-cell proliferation, we found that only approximately half of the cells that exhibited specific binding to influenza tetramer also proliferated, as measured by dye dilution, and synthesized IFNgamma in response to antigen. We expect the advent of new cell tracking dyes emitting from the violet to the near infrared combined with the increasing number of lasers and detectors on contemporary flow cytometers to further expand the usefulness of this approach to characterization of complex antigen-driven immunological responses. PMID:18785636

Wallace, Paul K; Tario, Joseph D; Fisher, Jan L; Wallace, Stephen S; Ernstoff, Marc S; Muirhead, Katharine A

2008-11-01

377

Dye Doped Ormosil Materials for Solid State Dye Laser  

Microsoft Academic Search

Organically Modified Silicate (ORMOSIL) materials doped with organic dyes (Rhodamine 6G, Rhodamine B) have been prepared from sol-gel derived using Methyltrimethoxysilane (MTMS) as precursor. The synthesis process was investigated step by step using Raman spectroscopy, and the experimental results demonstrated that Methyl group bounds to silica oxide network remain in the final materials. Broadband laser emission of the materials has

Tran Hong Nhung; Nghiem Ha Lien; A. Brun; Vu Thi Bich; Nguyen Xuan Nghia; Do Quang Hoa; Truong Thi Anh Dao; Nguyen Dai Hung

2001-01-01

378

PHOTOLYSIS OF SMOKE DYES ON SOILS  

EPA Science Inventory

Photolysis of an azo, a quinophthalone, and several anthraquinone smoke dyes was studied on soil surfaces. nitially, rapid photodegradation of each dye occurred, followed by a period of much slower rate of loss, indicating that the remaining fraction of the dye was photochemicall...

379

Environmentally Friendly Natural Dyeing of Organic Cotton  

Microsoft Academic Search

In this study, organic cotton fabrics were dyed with different natural dye sources (madder root, walnut shell, henna, horse chestnut, pomegranate peel, berberis vulgaris root, thyme, and sage tea). The dyeing was carried out with different mordants (copper sulphate, potassium aluminum sulphate, potassium tartrate, and citric acid), using pre-mordanting dyeing methods. The color of the fabrics was investigated in terms

Mustafa Tutak; N. Ebru Korkmaz

2012-01-01

380

Microbial decolourisation and degradation of textile dyes  

Microsoft Academic Search

Dyes and dyestuffs find use in a wide range of industries but are of primary importance to textile manufacturing. Wastewater from the textile industry can contain a variety of polluting substances including dyes. Increasingly, environmental legislation is being imposed to control the release of dyes, in particular azo-based compounds, into the environment. The ability of microorganisms to decolourise and metabolise

G. McMullan; C. Meehan; A. Conneely; N. Kirby; T. Robinson; P. Nigam; I. M. Banat; R. Marchant; W. F. Smyth

2001-01-01

381

Extreme ultra-violet movie camera for imaging microsecond time scale magnetic reconnection  

SciTech Connect

An ultra-fast extreme ultra-violet (EUV) movie camera has been developed for imaging magnetic reconnection in the Caltech spheromak/astrophysical jet experiment. The camera consists of a broadband Mo:Si multilayer mirror, a fast decaying YAG:Ce scintillator, a visible light block, and a high-speed visible light CCD camera. The camera can capture EUV images as fast as 3.3 × 10{sup 6} frames per second with 0.5 cm spatial resolution. The spectral range is from 20 eV to 60 eV. EUV images reveal strong, transient, highly localized bursts of EUV radiation when magnetic reconnection occurs.

Chai, Kil-Byoung; Bellan, Paul M. [Applied Physics, Caltech, 1200 E. California Boulevard, Pasadena, California 91125 (United States)] [Applied Physics, Caltech, 1200 E. California Boulevard, Pasadena, California 91125 (United States)

2013-12-15

382

High light extraction efficiency in bulk-GaN based volumetric violet light-emitting diodes  

NASA Astrophysics Data System (ADS)

We report on the light extraction efficiency of III-Nitride violet light-emitting diodes with a volumetric flip-chip architecture. We introduce an accurate optical model to account for light extraction. We fabricate a series of devices with varying optical configurations and fit their measured performance with our model. We show the importance of second-order optical effects like photon recycling and residual surface roughness to account for data. We conclude that our devices reach an extraction efficiency of 89%.

David, Aurelien; Hurni, Christophe A.; Aldaz, Rafael I.; Cich, Michael J.; Ellis, Bryan; Huang, Kevin; Steranka, Frank M.; Krames, Michael R.

2014-12-01

383

Defect-engineered GaN:Mg nanowire arrays for overall water splitting under violet light  

NASA Astrophysics Data System (ADS)

We report that by engineering the intra-gap defect related energy states in GaN nanowire arrays using Mg dopants, efficient and stable overall neutral water splitting can be achieved under violet light. Overall neutral water splitting on Rh/Cr2O3 co-catalyst decorated Mg doped GaN nanowires is demonstrated with intra-gap excitation up to 450 nm. Through optimized Mg doping, the absorbed photon conversion efficiency of GaN nanowires reaches ˜43% at 375-450 nm, providing a viable approach to extend the solar absorption of oxide and non-oxide photocatalysts.

Kibria, M. G.; Chowdhury, F. A.; Zhao, S.; Trudeau, M. L.; Guo, H.; Mi, Z.

2015-03-01

384

Single crystal growth of LaCuOS by the flux method  

Microsoft Academic Search

Preparation of single crystals of LaCuOS, that is a transparent p-type semiconductor exhibiting violet-light emission, was demonstrated by the flux method using NaCl+KCl(1:1) as flux. The crystals were grown in an alumina tube inserted in an evacuated silica glass tube using the starting materials of La2O2S and Cu2S, as well as the flux and a small amount of K2S that

Yutaka Nakachi; Kazushige Ueda

2008-01-01

385

NMR Spectroscopy of Azo Dyes  

Microsoft Academic Search

The known NMR spectroscopy data on different types of synthetic azo and polyazo dyes, including metal complexes, are correlated. The fundamentally new opportunities in the NMR spectroscopy of 1H, 13C, and 15N nuclei in solving problems of structural chemistry in this field of industrial chemistry are demonstrated. The bibliography includes 124 references.

L A Fedorov

1988-01-01

386

NMR Spectroscopy of Azo Dyes  

NASA Astrophysics Data System (ADS)

The known NMR spectroscopy data on different types of synthetic azo and polyazo dyes, including metal complexes, are correlated. The fundamentally new opportunities in the NMR spectroscopy of 1H, 13C, and 15N nuclei in solving problems of structural chemistry in this field of industrial chemistry are demonstrated. The bibliography includes 124 references.

Fedorov, L. A.

1988-10-01

387

The chromonic phases of dyes  

Microsoft Academic Search

It has been shown that the lyotropic liquid-crystalline phases formed by certain dyes are structurally analogous to the chromonic N and M liquid-crystalline phases previously thought to be unique to certain anti-asthmatic\\/anti-allergic drugs. We suspect that these two groups of compounds will prove to be representatives of a large new class of mesogenic materials.

T. K. Attwood; J. E. Lydon; F. Jones

1986-01-01

388

Products of photodegradation for coumarin laser dyes  

NASA Astrophysics Data System (ADS)

The products of conventional photolysis of the coumarin laser dyes, Cl, C35, Cl53, and Cl52 have been investigated. The previously reported dealkylation of Cl is documented for the fluorinated dyes, C35, and Cl52 in deaerated solvents. In addition, a reduction product is identified for Cl, consistent with a radical mechanism for decomposition. Evidence is provided that the concentration quenching (self quenching) of singlet dye is important to the degradation mechanism. For the rigid dye, Cl53, a photooxidation product involving the amine functionality results from decomposition in aerated media. For several dyes, very low triplet yields have been measured.

Jones, G., II; Jackson, W. R.; Kanoktanaporn, S.; Bergmark, W. R.

1983-10-01

389

Products of photodegradation for coumarin laser dyes  

NASA Astrophysics Data System (ADS)

The products of conventional photolysis of the coumarin laser dyes, C1, C35, C153, and C152 have been investigated. The previously reported dealkylation of C1 is documented for the fluorinated dyes, C35, and C152 in deaerated solvents. In addition, a reduction product is identified for C1, consistent with a radical mechanism for decomposition. Evidence is provided that the concentration quenching (self quenching) of singlet dye is important to the degradation mechanism. For the rigid dye, C153, a photooxidation product involving the amine functionality results from decomposition in aerated media. For several dyes, very low triplet yields have been measured.

Jones, Guilford; Bergmark, W. R.; Jackson, W. R.

1984-07-01

390

Tailoring of UV/violet plasmonic properties in Ag, and Cu coated Al concaves arrays  

NASA Astrophysics Data System (ADS)

UV plasmonics is of particular interest because of large variety of applications, where the higher energy plasmon resonances would advance scientific achievements, including surface-enhanced Raman scattering (SERS) with UV excitation, ultrasensitive label-free detection of important biomolecules absorbing light in the UV, or the possibility for exerting control over photochemical reactions. Despite its potential, UV plasmonics is still in its infancy, mostly due to difficulties in fabrication of reproducible nanostructured materials operating in this high energy range. Here, we present a simple electrochemical method to fabricate regular arrays of aluminum concaves demonstrating plasmonic properties in UV/violet region. The method enables the preparation of concaves with well-controlled geometrical parameters such as interpore distance (Dc), and therefore, well controllable plasmon resonances. Moreover, the patterning is suitable for large scale production. The UV/violet properties of Al concaves can be further fine-tuned by Ag and Cu metals. The refractive index sensitivity (RIS) increases after the metals deposition as compared to RIS of pure Al nanohole arrays. The highest RIS of 404 nm/RIU was obtained for Cu coated Al nanoconcaves with the Dc = 460.8 nm, which is similar or better than the RIS values previously reported for other nanohole arrays, operating in visible/near IR range.

Norek, Ma?gorzata; W?odarski, Maksymilian; St?pniowski, Wojciech J.

2014-09-01

391

An analysis on effecting factors of ultra-violet imaging appliance in corona discharge  

NASA Astrophysics Data System (ADS)

In this paper, the operating principle of daylight UV imagers was introduced first, emphasizing the SBUV(solar blind UV) technology, which utilizes the fact that ultra violet between 240nm~280nm is being absorbed by the ozone so that signals detected on earth in this spectral range originate on earth. And then several influencing factors were explained, including observation distance, observing angle, imager gain settings and environmental conditions. Experimental data measured in the UHV(ultra high-voltage) DC converter station in Changzhi, Shanxi, China were analyzed using SRA(single regression analysis) method, and mathematical equations with acceptable deviation were calculated, with simulating curves plotted. The results show that environmental conditions including humidity and temperature, observation distance and imager gain settings all contribute to the measuring result, exhibiting as exponential function and convex function respectively. Concluded from the above analysis and calculation, observing conditions of a clear observing angle at the same observation distance with mediate gain settings on days of low humidity were recommended. This conclusion may guide further ultra-violet imaging appliance in high-voltage electrical devices corona discharge sensing.

Han, Xiao; Yang, Ning; Yuan, Shuai; Bi, Jiangang

2014-11-01

392

Violet laser acupuncture--part 4: acute effects on human arterial stiffness and wave reflection.  

PubMed

We investigated the effects of violet laser acupuncture on arterial stiffness and other important parameters of the functional state of the heart such as augmentation index (AIx). This investigation ties together the medical perspectives of Eastern and Western medical practitioners; the Western medical perspective of the functional states of the human heart including systolic and diastolic blood pressures, and the Eastern medical perspective regarding taking patients' pulses for diagnosis and using acupuncture for subsequent treatments. Pulse wave velocity (PWV) is a direct marker of arterial stiffness; AIx indicates wave reflection. Both parameters can be measured by cuff applied to the brachial artery. The first results from a pilot study of 10 healthy volunteers (M/F, 3/7; mean age ± SD, 27.8 ± 6.8 years) regarding violet laser acupuncture (405 nm; 110 mW; 500 ?m; 10 min) showed a marked but not statistically significant decrease in aortic PWV and an increase in brachial AIx during and after laser acupuncture at the acupoint Baihui. Further studies including control measurements are necessary. PMID:21981867

Litscher, Gerhard; Wang, Lu; Gaischek, Ingrid; Gao, Xin-Yan

2011-09-01

393

Decolourization of textile industry wastewater by the photocatalytic degradation process  

Microsoft Academic Search

The photocatalytic degradation of various dyes (Orange II, Orange G, Congo Red, Indigo Carmine, Crystal Violet, Malachite Green, Remazol Blue and Methyl Yellow) has been studied, using P25 Degussa as catalyst. All dye solutions underwent a decolourization. The kinetics of reaction have been studied and were found to be zero or first order with respect to the dyes. This was

C Hachem; F Bocquillon; O Zahraa; M Bouchy

2001-01-01

394

Bright, efficient, and color-stable violet ZnSe-based quantum dot light-emitting diodes  

NASA Astrophysics Data System (ADS)

In this paper, highly stable violet-blue emitting ZnSe/ZnS core/shell QDs have been synthesized by a novel ``low temperature injection and high temperature growth'' method. The resulting nearly monodisperse ZnSe/ZnS core/shell QDs exhibit excellent characteristics such as a high color saturation (typical spectral full width at half-maximum between 12 and 20 nm), good emission tunability in the violet-blue range of wavelengths from 400 to 455 nm, a high absolute PL quantum yield (up to 83%), and superior chemical and photochemical stability. By employing ZnSe/ZnS core/shell quantum dots (QDs) as emitters with a fully solution processable method, bright, efficient, and color-stable violet Cd-free quantum dot-based light-emitting diodes (QD-LEDs) with maximum luminance up to 2632 cd m-2 and a peak EQE of 7.83% have been demonstrated successfully. Considering the factors of the photopic luminosity function, the brightness and efficiency results of such violet QD-LEDs not only represent a 12-fold increase in device efficiency and an extraordinary 100 times increase in luminance compared with previous Cd-free QD-LEDs but also can be much superior to the best performance (1.7%) of their Cd-based violet counterparts. These results demonstrate significant progress in short-wavelength QD-LEDs and shed light on the acceleration of commercial application of environmentally-friendly violet QD-based displays and lighting.In this paper, highly stable violet-blue emitting ZnSe/ZnS core/shell QDs have been synthesized by a novel ``low temperature injection and high temperature growth'' method. The resulting nearly monodisperse ZnSe/ZnS core/shell QDs exhibit excellent characteristics such as a high color saturation (typical spectral full width at half-maximum between 12 and 20 nm), good emission tunability in the violet-blue range of wavelengths from 400 to 455 nm, a high absolute PL quantum yield (up to 83%), and superior chemical and photochemical stability. By employing ZnSe/ZnS core/shell quantum dots (QDs) as emitters with a fully solution processable method, bright, efficient, and color-stable violet Cd-free quantum dot-based light-emitting diodes (QD-LEDs) with maximum luminance up to 2632 cd m-2 and a peak EQE of 7.83% have been demonstrated successfully. Considering the factors of the photopic luminosity function, the brightness and efficiency results of such violet QD-LEDs not only represent a 12-fold increase in device efficiency and an extraordinary 100 times increase in luminance compared with previous Cd-free QD-LEDs but also can be much superior to the best performance (1.7%) of their Cd-based violet counterparts. These results demonstrate significant progress in short-wavelength QD-LEDs and shed light on the acceleration of commercial application of environmentally-friendly violet QD-based displays and lighting. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr06593j

Wang, Aqiang; Shen, Huaibin; Zang, Shuaipu; Lin, Qingli; Wang, Hongzhe; Qian, Lei; Niu, Jinzhong; Song Li, Lin

2015-02-01

395

Supramolecular order following binding of the dichroic birefringent sulfonic dye Ponceau SS to collagen fibers.  

PubMed

The optical anisotropies (linear dichroism or LD and birefringence) of crystalline aggregates of the sulfonic azo-dye Ponceau SS and of dye complexed with chicken tendon collagen fibers were investigated in order to assess their polarizing properties and similarity to liquid crystals. In some experiments, the staining was preceded by treatment with picric acid. Crystalline fibrous aggregates of the dye had a negative LD, and their electronic transitions were oriented perpendicular to the filamentary structures. The binding of Ponceau SS molecules to the collagen fibers altered the LD signal, with variations in the fiber orientation affecting the resulting dichroic ratios. The long axis of the rod-like dye molecule was assumed to be bound in register, parallel to the collagen fiber. Picric acid did not affect the oriented binding of the azo dye to collagen fibers. There were differences in the optical anisotropy of Ponceau SS-stained tendons from 21-day-old and 41-day-old chickens, indicating that Ponceau SS was able to distinguish between different ordered states of macromolecular aggregation in chicken tendon collagen fibers. In the presence of dichroic rod-like azo-dye molecules such as Ponceau SS, collagen also formed structures with a much higher degree of orientation. The presence of LD in the Ponceau SS-collagen complex even in unpolarized light indicated that this complex can act as a polarizer. PMID:15844217

Vidal, B C; Mello, M L S

2005-06-15

396

Bright, efficient, and color-stable violet ZnSe-based quantum dot light-emitting diodes.  

PubMed

In this paper, highly stable violet-blue emitting ZnSe/ZnS core/shell QDs have been synthesized by a novel "low temperature injection and high temperature growth" method. The resulting nearly monodisperse ZnSe/ZnS core/shell QDs exhibit excellent characteristics such as a high color saturation (typical spectral full width at half-maximum between 12 and 20 nm), good emission tunability in the violet-blue range of wavelengths from 400 to 455 nm, a high absolute PL quantum yield (up to 83%), and superior chemical and photochemical stability. By employing ZnSe/ZnS core/shell quantum dots (QDs) as emitters with a fully solution processable method, bright, efficient, and color-stable violet Cd-free quantum dot-based light-emitting diodes (QD-LEDs) with maximum luminance up to 2632 cd m(-2) and a peak EQE of 7.83% have been demonstrated successfully. Considering the factors of the photopic luminosity function, the brightness and efficiency results of such violet QD-LEDs not only represent a 12-fold increase in device efficiency and an extraordinary 100 times increase in luminance compared with previous Cd-free QD-LEDs but also can be much superior to the best performance (1.7%) of their Cd-based violet counterparts. These results demonstrate significant progress in short-wavelength QD-LEDs and shed light on the acceleration of commercial application of environmentally-friendly violet QD-based displays and lighting. PMID:25588101

Wang, Aqiang; Shen, Huaibin; Zang, Shuaipu; Lin, Qingli; Wang, Hongzhe; Qian, Lei; Niu, Jinzhong; Song Li, Lin

2015-02-21

397

Improving optical absorptivity of natural dyes for fabrication of efficient dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

Efficient and cheap dye-sensitized solar cells (DSSCs) were fabricated using natural dyes from Pastinaca sativa and Beta vulgaris. Natural dyes are environmentally and economically superior to ruthenium-based dyes because they are nontoxic and cheap. However, the conversion efficiency of dye-sensitized solar cells based on natural dyes is low. One way to improve the DSSC performance is to enhance the absorptivity of extracted dyes. We investigated the influence of various factors in the extraction process, such as utilization of different extraction approaches, the acidity of extraction solvent, and different compounds of solvents on the optical absorption spectra. It was found that we could considerably enhance the optical absorptivity of dye and consequently the performance of DSSC by choosing a proper mixture of ethanol and water for extracting solvent and also the acidity of dye solution.

Hemmatzadeh, Reza; Mohammadi, Ahmad

2013-11-01

398

Dyeing of Jute with Reactive Dyes: Optimisation of the Process Variables and Assessment of Colourfastness Characteristics  

NASA Astrophysics Data System (ADS)

This paper deals with the studies on the effect of dye concentration, electrolyte (common salt) concentration, dyeing time, dyeing temperature, soda ash concentration, pH of the dye solution and material to liquor ratio (MLR) on colour strength and other colour parameters after being dyed of jute fabrics with reactive dyes, namely, Turquoise blue, Lemon Yellow, Red CN colours. The dye absorption increases with increase in electrolyte (common salt) concentration, dyeing time, dyeing temperature, soda ash concentration, pH and decreases with increase of MLR. Colour fastness to wash, light and rubbing for the dyed samples has been studied and reported. It is observed that reactive dye gives overall good colour fastness to both washing and rubbing. But the light fastness has been found to be moderate only, due to the UV-light initiated fading of jute fibre itself change of the colour substrate, ie, undyed material. This colour fastness has been significantly resolved by post treatment with 1 % benzotriazole.

Samanta, A. K.; Chakraborty, Sharmistha; Guha Roy, T. K.

2012-08-01

399

Determination of dye intermediates in oxidative hair dyes by fused-silica capillary gas chromatography.  

PubMed

A fused-silica capillary gas chromatographic method is described for the determination of dye intermediates in oxidative hair dyes. An appropriate amount of hair dye sample is dissolved in 10 ml of methanol containing 0.25 g of ammonium thioglycolate and an appropriate amount of 2-amino-4-methylphenol as an internal standard. This solution is directly injected into a gas chromatograph. A fused-silica capillary column with cross-linked methyl silicone OV-1 or SE-54 as a liquid phase yields excellent resolution of dye intermediates. Some factors affecting the quantitation of dye intermediates are discussed. The proposed method gave good recoveries and reproducibilities, and permits simultaneous determination of various types of dye intermediates without any pretreatment. The use of a nitrogen-phosphorus detector allows the selective detection of nitrogen-containing dye intermediates. This simple and versatile method is applicable for the determination of dye intermediates in commercial hair dyes. PMID:3782349

Tokuda, H; Kimura, Y; Takano, S

1986-10-01

400

Characteristics of a Broadband Dye Laser Using Pyrromethene and Rhodamine Dyes  

NASA Technical Reports Server (NTRS)

A broadband dye laser pumped by a frequency-doubled Nd:YAG laser with a full-width half-maximum (FWHM) from 592 to 610 nm was created for the use in a dual-pump broadband CARS system called WIDECARS. The desired broadband dye laser was generated with a mixture of Pyrromethene dyes as an oscillator gain medium and a spectral selective optic in the oscillator cavity. A mixture of Rhodamine dyes were used in the amplifier dye cell. To create this laser a study was performed to characterize the spectral behavior of broadband dye lasers created with Rhodamine dyes 590, 610, and 640, Pyrromethene dyes 597 and 650 as well as mixture of these dyes.

Tedder, Sarah A.; Danehy, Paul M.; Wheeler, Jeffrey L.

2011-01-01

401

A critical comparison of molecular reorientation in the ground and excited electronic states: Cresyl violet in methanol  

NASA Astrophysics Data System (ADS)

Picosecond techniques were used to study the rotational diffusion of the ground and first excited electronic states of cresyl violet in methanol. The anisotropy decay was studied at five different wavelengths, three in the ground state and two in the excited state. It is known that the decay of the anisotropy is dependent on both the transition polarization and rotational diffusion constants. Experimentally, a different decay of the anisotropy is observed at each wavelength. The data are consistent with changes in the transition polarization but with the same diffusion constant in all cases. It is concluded that cresyl violet in methanol reorients identically in its ground and excited electronic states.

Blanchard, G. J.; Wirth, M. J.

1985-01-01

402

Induction, purification and characterization of a novel manganese peroxidase from Irpex lacteus CD2 and its application in the decolorization of different types of dye.  

PubMed

Manganese peroxidase (MnP) is the one of the important ligninolytic enzymes produced by lignin-degrading fungi which has the great application value in the field of environmental biotechnology. Searching for new MnP with stronger tolerance to metal ions and organic solvents is important for the maximization of potential of MnP in the biodegradation of recalcitrant xenobiotics. In this study, it was found that oxalic acid, veratryl alcohol and 2,6-Dimehoxyphenol could stimulate the synthesis of MnP in the white-rot fungus Irpex lacteus CD2. A novel manganese peroxidase named as CD2-MnP was purified and characterized from this fungus. CD2-MnP had a strong capability for tolerating different metal ions such as Ca2+, Cd2+, Co2+, Mg2+, Ni2+ and Zn2+ as well as organic solvents such as methanol, ethanol, DMSO, ethylene glycol, isopropyl alcohol, butanediol and glycerin. The different types of dyes including the azo dye (Remazol Brilliant Violet 5R, Direct Red 5B), anthraquinone dye (Remazol Brilliant Blue R), indigo dye (Indigo Carmine) and triphenylmethane dye (Methyl Green) as well as simulated textile wastewater could be efficiently decolorized by CD2-MnP. CD2-MnP also had a strong ability of decolorizing different dyes with the coexistence of metal ions and organic solvents. In summary, CD2-MnP from Irpex lacteus CD2 could effectively degrade a broad range of synthetic dyes and exhibit a great potential for environmental biotechnology. PMID:25412169

Qin, Xing; Zhang, Jie; Zhang, Xiaoyu; Yang, Yang

2014-01-01

403

Induction, Purification and Characterization of a Novel Manganese Peroxidase from Irpex lacteus CD2 and Its Application in the Decolorization of Different Types of Dye  

PubMed Central

Manganese peroxidase (MnP) is the one of the important ligninolytic enzymes produced by lignin-degrading fungi which has the great application value in the field of environmental biotechnology. Searching for new MnP with stronger tolerance to metal ions and organic solvents is important for the maximization of potential of MnP in the biodegradation of recalcitrant xenobiotics. In this study, it was found that oxalic acid, veratryl alcohol and 2,6-Dimehoxyphenol could stimulate the synthesis of MnP in the white-rot fungus Irpex lacteus CD2. A novel manganese peroxidase named as CD2-MnP was purified and characterized from this fungus. CD2-MnP had a strong capability for tolerating different metal ions such as Ca2+, Cd2+, Co2+, Mg2+, Ni2+ and Zn2+ as well as organic solvents such as methanol, ethanol, DMSO, ethylene glycol, isopropyl alcohol, butanediol and glycerin. The different types of dyes including the azo dye (Remazol Brilliant Violet 5R, Direct Red 5B), anthraquinone dye (Remazol Brilliant Blue R), indigo dye (Indigo Carmine) and triphenylmethane dye (Methyl Green) as well as simulated textile wastewater could be efficiently decolorized by CD2-MnP. CD2-MnP also had a strong ability of decolorizing different dyes with the coexistence of metal ions and organic solvents. In summary, CD2-MnP from Irpex lacteus CD2 could effectively degrade a broad range of synthetic dyes and exhibit a great potential for environmental biotechnology. PMID:25412169

Qin, Xing; Zhang, Jie; Zhang, Xiaoyu; Yang, Yang

2014-01-01

404

Infrared liquid crystal polymer micropolarizer.  

PubMed

The ability to create arbitrary patterned linear and circular infrared (IR) liquid crystal polymer (LCP) polarizers is demonstrated. The operating wavelength of the thin-film polarizer ranges from 700 to 4200 nm. The linear micropolarizer is fabricated using IR dichroic dye as a guest in LCP host with feature size as small as 4 ?m. The circular micropolarizer is fabricated using cholesteric LCPs with feature size as small as 6.2 ?m. PMID:25320936

Hsu, Wei-Liang; Balakrishnan, Kaushik; Ibn-Elhaj, Mohammed; Pau, Stanley

2014-08-10

405

Dye-sensitized solar cells based on axially ligated phosphorus-phthalocyanine dyes  

NASA Astrophysics Data System (ADS)

Dye-sensitized solar cells with axially anchored phosphorous-phthalocyanine dyes were fabricated for the first time. Although the phosphorus-phthalocyanine dyes do not have a conventional anchoring group (–COOH), these dyes could be absorbed on a TiO2 semiconductor surface. After the optimization of energy levels, a 24% incident photon-to-current efficiency (IPCE) was observed at 710 nm with an IPCE curve edge of 800 nm. The efficiency was 2.67%, which was higher than those of previously reported dye-sensitized solar cells with axially anchored phthalocyanine dyes (less than 1%).

Hayat, Azwar; Shivashimpi, Gururaj M.; Nishimura, Terumi; Fujikawa, Naotaka; Ogomi, Yuhei; Yamaguchi, Yoshihiro; Pandey, Shyam S.; Ma, Tingli; Hayase, Shuzi

2015-04-01

406

Studies on decolorization of reactive blue 19 textile dye by Coprinus plicatilis  

PubMed Central

Background Studies were carried on the decolorization of the textile dye reactive blue 19 (RB 19) by a novel isolate of Coprinus plicatilis (C. plicatilis) fungi. We describe an in vitro optimization process for decolorization and its behavior under different conditions of carbon and nitrogen sources, pH, temperature and substrate concentration. Results The optimal conditions for decolorization were obtained in media containing intermediate concentrations of ammonium oxalate and glucose (10 g/L) as nitrogen and carbon sources, respectively, at 26°C and pH?=?5.5. Maximum decolorization efficiency against RB 19 achieved in this study was around 99%. Ultra-violet and visible (UV-vis) spectrophotometric analyses, before and after decolorization, suggest that decolorization was due to biodegradation. Conclusions This effect was associated with laccase enzyme displaying good tolerance to a wide range of pH values, salt concentrations and temperatures, suggesting a potential role for this organism in the remediation of real dye containing effluents. In conclusion, laccase activity in C. plicatilis was firstly described in this study. PMID:24565535

2014-01-01

407

Dye alignment in luminescent solar concentrators: II. Horizontal alignment for energy harvesting in linear polarizers  

SciTech Connect

We describe Linearly Polarized Luminescent Solar Concentrators (LP-LSCs) to replace conventional, purely absorptive, linear polarizers in energy harvesting applications. As a proof of concept, we align 3-(2-Benzothiazolyl)-N,N-diethylumbelliferylamine (Coumarin 6) and 4-dicyanomethyl-6-dimethylaminostiryl-4H-pyran (DCM) dye molecules linearly in the plane of the substrate using a polymerizable liquid crystal host. We show that up to 38% of the photons polarized on the long axis of the dye molecules can be coupled to the edge of the device for an LP-LSC based on Coumarin 6 with an order parameter of 0.52.

Mulder, Carlijn L.; Reusswig, Phil D.; Beyler, A. P.; Kim, Heekyung; Rotschild, Carmel; Baldo, Marc

2010-01-01

408

Steady-state and time-resolved fluorescence study of some dyes in polymer microspheres showing morphology dependent resonances  

NASA Astrophysics Data System (ADS)

Fluorescence emission spectra of N,N'-bis(2,5-di-tert-butylphenyl)-3,4:9,10- Perylenebis(dicarboximide) (DBPI), rhodamine 6G (R6G), and cresyl violet (CV) in spherical polymer beads of less than 20 ?m diameter show sharp ripple structures. The observed peak positions and the intervals of the structures are consistent with the calculations of the morphology dependent resonances (MDR). Observed intensities of the MDR in the fluorescence emission spectra are found to show excitation energy dependence. The fluorescence spectra have also been measured as a function of the refractive indexes of the medium and the bead. These MDR in the beads up to 4 ?m diameter do not appear to affect the fluorescence decay of the dyes, since the fluorescence lifetime remains constant irrespective of the size of the bead and the refractive index of a surrounding medium. Simulations based on the Lorentz-Mie theory for the microspheres of different refractive indexes have been used to quantify the observed effect on the basis of the available data on the homogeneous widths of the dye molecules. A fluorescence study of microcrystals of DBPI is also presented here from the point of view of comparison with fluorescence decay of dye impregnated beads. The microcrystals exhibit a size effect in the fluorescence decay which has been attributed mainly to the self-absorption effect.

Bisht, Prem B.; Fukuda, Kazuhiro; Hirayama, Satoshi

1996-11-01

409

Site-selection spectroscopy and hole-burning of ionic dyes in amorphous hosts at low temperature  

NASA Astrophysics Data System (ADS)

The hole-burning (HB) mechanism of the ionic dyes resorufin and cresyl violet was investigated in various glasses and polymers at liquid helium temperature. By means of hole-filling experiments the spectral distance of the photoproduct absorption maximum to that of the original molecule ? max was determined. It was observed that ? max and the electron-phonon coupling strength, S, increase with host polarity, Z, in the ionic dyes studied, whereas ? max and S are both independent of Z in the neutral free-base porphin molecule. A linear relation between ? max and S was found for all cases. The results suggest that these ionic dye systems undergo intermolecular photochemical hole-burning with high HB efficiency. Furthermore, two differently solvated species of resorufin in alcoholic glasses (ethanol and glycerol) were identified, and the vibrational frequencies of ground and first excited singlet states were obtained for both species. It is inferred that one of the species is hydrogen bonded to the host, whereas the other is a "free" resorufin molecule. Although hydrogen-bonding solvents enhance the HB efficiency, they are not necessary for the hole-burning process to occur.

Van den berg, R.; Völker, S.

1988-12-01

410

Current Status of Dichroic Liquid Crystal Displays  

Microsoft Academic Search

This paper reviews the operational principle, construction and electro-optical performance of various types of dichroic liquid crystal displays such as Heilmeier, phase change, dye doped TN and polymer dispersed dichroic. It also discusses the double layer and positive mode dichroic LCDs. The impact of material properties such as birefringence, dielectric anisotropy, viscosity, elastic constant and cell construction such as alignment,

B. Bahadur

1991-01-01

411

BODIPY Dyes In Photodynamic Therapy  

PubMed Central

BODIPY dyes tends to be highly fluorescent, but their emissions can be attenuated by adding substituents with appropriate oxidation potentials. Substituents like these have electrons to feed into photoexcited BODIPYs, quenching their fluorescence, thereby generating relatively long-lived triplet states. Singlet oxygen is formed when these triplet states interact with 3O2. In tissues, this causes cell damage in regions that are illuminated, and this is the basis of photodynamic therapy (PDT). The PDT agents that are currently approved for clinical use do not feature BODIPYs, but there are many reasons to believe that this situation will change. This review summarizes the attributes of BODIPY dyes for PDT, and in some related areas. PMID:23014776

Kamkaew, Anyanee; Lim, Siang Hui; Lee, Hong Boon; Kiew, Lik Voon; Chung, Lip Yong

2012-01-01

412

BODIPY dyes in photodynamic therapy.  

PubMed

BODIPY dyes tend to be highly fluorescent, but their emissions can be attenuated by adding substituents with appropriate oxidation potentials. Substituents like these have electrons to feed into photoexcited BODIPYs, quenching their fluorescence, thereby generating relatively long-lived triplet states. Singlet oxygen is formed when these triplet states interact with (3)O(2). In tissues, this causes cell damage in regions that are illuminated, and this is the basis of photodynamic therapy (PDT). The PDT agents that are currently approved for clinical use do not feature BODIPYs, but there are many reasons to believe that this situation will change. This review summarizes the attributes of BODIPY dyes for PDT, and in some related areas. PMID:23014776

Kamkaew, Anyanee; Lim, Siang Hui; Lee, Hong Boon; Kiew, Lik Voon; Chung, Lip Yong; Burgess, Kevin

2013-01-01

413

Batchwise dyeing of bamboo cellulose fabric with reactive dye using ultrasonic energy.  

PubMed

Bamboo is a regenerated cellulose fiber usually dyed with reactive dyes. This paper presents results of the batchwise dyeing of bamboo fabric with reactive dyes by ultrasonic (US) and conventional (CN) dyeing methods. The study was focused at comparing the two methods for dyeing results, chemicals, temperature and time, and effluent quality. Two widely used dyes, CI Reactive Black 5 (bis-sulphatoethylsulphone) and CI Reactive Red 147 (difluorochloropyrimidine) were used in the study. The US dyeing method produced around 5-6% higher color yield (K/S) in comparison to the CN dyeing method. A significant savings in terms of fixation temperature (10°C) and time (15 min), and amounts of salt (10 g/L) and alkali (0.5-1% on mass of fiber) was realized. Moreover, the dyeing effluent showed considerable reductions in the total dissolved solids content (minimum around 29%) and in the chemical oxygen demand (minimum around 13%) for the US dyebath in comparison to the CN dyebath. The analysis of colorfastness tests demonstrated similar results by US and CN dyeing methods. A microscopic examination on the field emission scanning electron microscope revealed that the US energy did not alter the surface morphology of the bamboo fibers. It was concluded that the US dyeing of bamboo fabric produces better dyeing results and is a more economical and environmentally sustainable method as compared to CN dyeing method. PMID:25575805

Larik, Safdar Ali; Khatri, Awais; Ali, Shamshad; Kim, Seong Hun

2015-05-01

414

INHALATION TOXICOLOGY OF RED AND VIOLET MIXTURES - CHAMBER CONCENTRATION AND PARTICLE SIZE DISTRIBUTION REPORT  

EPA Science Inventory

An inhalation exposure facility was developed at the U.S. EPA, RTP, NC to conduct inhalation exposures of rodents and guinea pigs to dye mixtures used by the U.S. Army in the manufacture of smoke munitions. nitially, an evaluation of the prototype chamber aerosol homogeneity was ...

415

Dye laser traveling wave amplifier  

NASA Technical Reports Server (NTRS)

A flashlamp pumped dye laser suitable for use as a single stage amplifier is described. Particular emphasis is placed on the efforts to increase output pulse energy and improve the temporal profile of the injected pulse. By using high power thin film polarizers, output energies reach from 4 to 45 mJ. Various dispersive elements are used to develop an amplified pulse with an extremely clean temporal profile.

Davidson, F.; Hohman, J.

1984-01-01

416

Enzymatic decolorization of sulfonphthalein dyes  

Microsoft Academic Search

The white rot fungus (WRF) Pleurotus ostreatus produced manganese peroxidase (MnP) and manganese-independent peroxidase (MIP) activities during solid state fermentation of wheat straw, a natural lignocellulosic substrate. Most of the sulfonphthalein (SP) dyes were decolorized by MnP at pH 4.0. The higher Km for meta-cresol purple (40?M) and lower Km for ortho-cresol red (26?M) for MnP activities explained the preference

R. Shrivastava; V. Christian; B. R. M. Vyas

2005-01-01

417

Dye-Sensitized Solar Cells  

NSDL National Science Digital Library

This lesson from The Lawrence Hall of Science was taught in spring 2012 and teaches students about nano and environmental technologies. Students will create "dye-sensitized solar cells (DSSC) using nano-crystalline titanium dioxide." This page includes links to the Source Articles for the Hands-on Module and Project Staff Write-ups of the Hands-on Module. Additionally, five documents provide lecture and lab materials for instructor use.

418

Dye laser traveling wave amplifier  

NASA Technical Reports Server (NTRS)

Injection locking was applied to a cavity-dumped coaxial flashlamp pumped dye laser in an effort to obtain nanosecond duration pulses which have both high energy and narrow-linewidth. In the absence of an injected laser pulse, the cavity-dumped dye laser was capable of generating high energy (approx. 60mJ) nanosecond duration output pulses. These pulses, however, had a fixed center wavelength and were extremely broadband (approx. 6nm FWHM). Experimental investigations were performed to determine if the spectral properties of these outputs could be improved through the use of injection-locking techniques. A parametric study to determine the specific conditions under which the laser could be injection-locked was also carried out. Significant linewidth reduction to 0.0015nm) of the outputs was obtained through injection-locking but only at wavelengths near the peak lasing wavelength of the dye. It was found, however; that by inserting weakly dispersive tuning elements in the laser cavity, these narrow-linewidth outputs could be obtained over a wide (24nm) tuning range. Since the tuning elements had low insertion losses, the tunability of the output was obtained without sacrificing output pulse energy.

Davidson, F.; Hohman, J.

1985-01-01

419

Probing the regeneration process of triphenylamine-based organic dyes in dye-sensitized solar cells  

NASA Astrophysics Data System (ADS)

The regeneration processes of triphenylamine (TPA)-based dyes with cobalt redox mediator in dye-sensitized solar cells (DSSCs) have been investigated using density functional theory combined with the Marcus theory of electron transfer. Our results show that with the extension or rigidification of the oligothiophene conjugation linker the absorption spectra of TPA dyes exhibit observable red-shift in the maximum absorbance that favors light-harvesting, while the electron transfer rates for dye regeneration decrease in some degrees due to the increased activation free energies and the reduced electronic coupling energies which hampers the dye regeneration. Importantly, the undesirable influences on dye regeneration by extending the linker moiety are more significant than that by the way of rigidification. Thus, the rigidification is a better choice than the extension of the conjugated moiety for the design of D-?-A type dyes based on the properties of light-harvesting and the kinetics of dye regeneration.

Sun, Zhu-Zhu; Li, Quan-Song; Sun, Ping-Ping; Li, Ze-Sheng

2015-02-01

420

Bias Selectable Dual Band AlGaN Ultra-violet Detectors  

NASA Technical Reports Server (NTRS)

Bias selectable dual band AlGaN ultra-violet (UV) detectors, which can separate UV-A and UV-B using one detector in the same pixel by bias switching, have been designed, fabricated and characterized. A two-terminal n-p-n photo-transistor-like structure was used. When a forward bias is applied between the top electrode and the bottom electrode, the detectors can successfully detect W-A and reject UV-B. Under reverse bias, they can detect UV-B and reject UV-A. The proof of concept design shows that it is feasible to fabricate high performance dual-band UV detectors based on the current AlGaN material growth and fabrication technologies.

Yan, Feng; Miko, Laddawan; Franz, David; Guan, Bing; Stahle, Carl M.

2007-01-01

421

Gentian Violet: A 19th Century Drug Re-Emerges in the 21st Century  

PubMed Central

Gentian violet (GV) has a long and varied history as a medicinal agent. Historically used as an anti-bacterial and anti-fungal, recent reports have shown its utility as an anti-typranosomal, anti-viral and anti-angiogenic agent. The objective of this paper is to summarize evidence regarding the efficacy, and safety of GV use in dermatology. Recent discoveries have found novel targets of GV, namely NADPH oxidase in mammalian cells and thioredoxin reductase 2 in bacterial, fungal, and parasitic cells. These discoveries have expanded the use of GV in the 21st century. Given that GV is well tolerated, effective and inexpensive, its use in dermatology is predicted to increase. PMID:24118276

Maley, Alexander M.; Arbiser, Jack L.

2013-01-01

422

Avian ultraviolet/violet cones as magnetoreceptors: The problem of separating visual and magnetic information.  

PubMed

In a recent paper, we described the localization of cryptochrome 1a in the retina of domestic chickens, Gallus gallus, and European robins, Erithacus rubecula: Cryptochrome 1a was found exclusively along the membranes of the disks in the outer segments of the ultraviolet/violet single cones. Cryptochrome has been suggested to act as receptor molecule for the avian magnetic compass, which would mean that the UV/V cones have a double function: they mediate vision in the short-wavelength range and, at the same time, magnetic directional information. This has important implications and raises a number of questions, in particular, how the two types of input are separated. Here, we point out several possibilities how this could be achieved.  PMID:22446535

Bischof, Hans-Joachim; Nießner, Christine; Peichl, Leo; Wiltschko, Roswitha; Wiltschko, Wolfgang

2011-11-01

423

True covariance simulation of the EUVE (extreme ultra violet explorer) update filter  

NASA Technical Reports Server (NTRS)

This paper presents a covariance analysis of the performance and sensitivity of the attitude determination Extended Kalman Filter (EKF) used by the onboard computer (OBC) of the Extreme Ultra Violet Explorer (EUVE) spacecraft. The linearized dynamics and measurement equations of the error states are used in formulating the 'truth model' describing the order of the systems involved. The 'design model' used by the OBC EKF is then obtained by reducing the order of the truth model. The covariance matrix of the EKF which uses the reduced order model is not the correct covariance of the EKF estimation error. A 'true covariance analysis' has to be carried out in order to evaluate the correct accuracy of the OBC generated estimates. The results of such analysis are presented which indicate both the performance and the sensitivity of the OBC EKF.

Bar-Itzhack, I. Y.; Harman, R. R.

1990-01-01

424

Detection of biological warfare agents using ultra violet-laser induced fluorescence LIDAR  

NASA Astrophysics Data System (ADS)

This review has been written to highlight the threat of biological warfare agents, their types and detection. Bacterial biological agent Bacillus anthracis (bacteria causing the disease anthrax) which is most likely to be employed in biological warfare is being discussed in detail. Standoff detection of biological warfare agents in aerosol form using Ultra violet-Laser Induced Fluorescence (UV-LIF) spectroscopy method has been studied. Range-resolved detection and identification of biological aerosols by both nano-second and non-linear femto-second LIDAR is also discussed. Calculated received fluorescence signal for a cloud of typical biological agent Bacillus globigii (Simulants of B. anthracis) at a location of ˜5.0 km at different concentrations in presence of solar background radiation has been described. Overview of current research efforts in internationally available working UV-LIF LIDAR systems are also mentioned briefly.

Joshi, Deepti; Kumar, Deepak; Maini, Anil K.; Sharma, Ramesh C.

425

Violet electroluminescence from p-GaN thin film/n-GaN nanowire homojunction  

NASA Astrophysics Data System (ADS)

The difficulty associated with the precise positioning of nanowires has been one of the most significant issues hindering nanoelectronic integration. In this paper, we employed dielectrophoretic force to manipulate n-type GaN nano- and microwires onto a p-type GaN thin film to form a pristine p-n homojunction. The GaN wires were attracted to the n-type Ohmic metal in a direction parallel to the electric field, which was consistent with our simulation results. Violet electroluminescence emanated from the point of the n-GaN wire in contact with the p-GaN thin film. This p-n homojunction device displayed forward conduction above 6-9 V and current rectifying behavior down to a -20 V reverse bias. The current-voltage characteristics are distinctive of a p-n homojunction formed without deleterious damage or contamination.

Ahn, Jaehui; Mastro, Michael A.; Hite, Jennifer; Eddy, Charles R.; Kim, Jihyun

2010-03-01

426

Brain Responses to Violet, Blue, and Green Monochromatic Light Exposures in Humans: Prominent Role of Blue Light and the Brainstem  

Microsoft Academic Search

BackgroundRelatively long duration retinal light exposure elicits nonvisual responses in humans, including modulation of alertness and cognition. These responses are thought to be mediated in part by melanopsin-expressing retinal ganglion cells which are more sensitive to blue light than violet or green light. The contribution of the melanopsin system and the brain mechanisms involved in the establishment of such responses

Gilles Vandewalle; Christina Schmidt; Geneviève Albouy; Virginie Sterpenich; Annabelle Darsaud; Géraldine Rauchs; Pierre-Yves Berken; Evelyne Balteau; Christian Degueldre; André Luxen; Pierre Maquet; Derk-Jan Dijk; Sheng He

2007-01-01

427

HPLC Determination and MS Confirmation of Malachite Green, Gentian Violet, and Their Leuco Metabolites in Catfish Muscle  

Technology Transfer Automated Retrieval System (TEKTRAN)

Residues of malachite green (MG), gentian violet (GV), and their leuco metabolites in catfish muscle were individually determined by HPLC using visible and fluorescence detectors. This detection scheme obviated a PbO2 column that converts leuco forms to chromatic forms for visible detection, thus el...

428

Gold nanoparticles functionalized with cresyl violet and porphyrin via hyaluronic acid for targeted cell imaging and phototherapy.  

PubMed

Gold nanoparticles are functionalized as a nanoprobe with cresyl violet and porphyrin via hyaluronic acid. The nanoprobe becomes highly fluorescent in the presence of hyaluronidase or under ultraviolet irradiation, and can be used to target cancer cells via the overexpressed CD44 receptor for fluorescence imaging and phototherapy. PMID:25361440

Song, Yanchao; Wang, Zhe; Li, Lihong; Shi, Wen; Li, Xiaohua; Ma, Huimin

2014-12-25

429

Terrific Trichomes (and Other Specialised Cells) in African Violets: How to Get a Lot from One Plant in the Classroom  

ERIC Educational Resources Information Center

African violet (genus "Saintpaulia") was identified as a particularly suitable genus for the study of specialised plant cells in the classroom using microscopes. The techniques described here involve simple preparation without staining. The cells and structures that can be investigated include: trichomes (hairs); stomata; guard cells and…

Cottrell, Vicki M.

2013-01-01

430

The physics of dye laser amplifiers  

NASA Astrophysics Data System (ADS)

This paper describes a method for the complete analysis of the optical properties of a laser dye. The analysis uses direct measurements of the saturation intensities for absorption and emission. The complete analysis of an ultraviolet laser dye, 3,5,3,5-Tetra-t-butyl-p-sexiphenyl, demonstrates the power of the saturation analysis method. The dye TBS exhibits some unique optical properties which affect its emission wavelength range and photochemistry.

Jensen, C. C.

431

Residual contaminants in dye-penetrant testing  

SciTech Connect

Components of the dye-penetrant-testing process were characterized by microanalytical methods. Particulate material of a size range, which was small enough to plug the small leaks in thin-walled cans, was found. Testing of simulated leaks before and after dye-penetrant examination showed that the dye-penetrant testing had a high probability of plugging leaks < 1 x 10/sup -4/ atm-cm/sup 3//s of helium in size.

McLaughlin, J.F.; Schneider, P.G.; Eager, M.H.

1981-04-13

432

Physical and chemical investigations on natural dyes  

Microsoft Academic Search

Natural dyes have been used extensively in the past for many purposes, such us to colour fibers and to produce inks, watercolours\\u000a and paints, but their use declined rapidly after the discovery of synthetic colours. Nowadays we witness a renewed interest,\\u000a as natural dyes are neither toxic nor polluting.\\u000a \\u000a \\u000a In this work, physical and chemical properties of four selected dyes,

S. Acquaviva; E. D’Anna; M. L. De Giorgi; P. Baraldi

2010-01-01

433

Effectiveness of various UV-absorbers in dyeing of polyester with disperse dyes. Part III  

Microsoft Academic Search

The effect of various amounts of two benzotriazole (Tinuvin P and Tinuvin 327) and one benzophenone (2,4-dihydroxybenzophenone) type UV-absorbers in the dyeing of polyester fabrics with commercial samples of a red monoazo disperse dye and Viosperse Yellow GLFS was examined at various depths of dyeing (0.5, 1.75 and 3% o.w.f.). The UV-absorbers were applied to the fibre at various UV-absorber\\/dye

A. H Kehayoglou; E. G Tsatsaroni; I. C Eleftheriadis; K. C Loufakis; L. E Kyriazis

1997-01-01

434

Fluorene-based sensitizers with a phenothiazine donor: effect of mode of donor tethering on the performance of dye-sensitized solar cells.  

PubMed

Two types of fluorene-based organic dyes featuring T-shape/rod-shape molecular configuration with phenothiazine donor and cyanoacrylic acid acceptor have been synthesized and characterized as sensitizers for dye-sensitized solar cells. Phenothiazine is functionalized at either nitrogen (N10) or carbon (C3) to obtain T-shape and rod-like organic dyes, respectively. The effect of structural alternation on the optical, electrochemical, and the photovoltaic properties is investigated. The crystal structure determination of the dye containing phenyl linker revealed cofacial slip-stack columnar packing of the molecules. The trends in the optical properties of the dyes are interpreted using time-dependent density functional theory (TDDFT) computations. The rod-shaped dyes exhibited longer wavelength absorption and low oxidation potentials when compared to the corresponding T-shaped dyes attributable to the favorable electronic overlap between the phenothiazine unit and the rest of the molecule in the former dyes. However, the T-shaped dyes showed better photovoltaic properties due to the lowest unoccupied molecular orbital (LUMO) energy level favorable for electron injection into the conduction band of TiO2 and appropriate orientation of the phenothiazine unit rendering effective surface blocking to suppress the recombination of electrons between the electrolyte I3(-) and TiO2. The electrochemical impedance spectroscopy investigations provide further support for the variations in the electron injection and transfer kinetics due to the structural modifications. PMID:25557120

Baheti, Abhishek; Justin Thomas, K R; Li, Chun-Ting; Lee, Chuan-Pei; Ho, Kuo-Chuan

2015-02-01

435

Fabrication of SnO2-Reduced Graphite Oxide Monolayer-Ordered Porous Film Gas Sensor with Tunable Sensitivity through Ultra-Violet Light Irradiation.  

PubMed

A new graphene-based composite structure, monolayer-ordered macroporous film composed of a layer of orderly arranged macropores, was reported. As an example, SnO2-reduced graphite oxide monolayer-ordered macroporous film was fabricated on a ceramic tube substrate under the irradiation of ultra-violet light (UV), by taking the latex microsphere two-dimensional colloid crystal as a template. Graphite oxide sheets dispersed in SnSO4 aqueous solution exhibited excellent affinity with template microspheres and were in situ incorporated into the pore walls during UV-induced growth of SnO2. The growing and the as-formed SnO2, just like other photocatalytic semiconductor, could be excited to produce electrons and holes under UV irradiation. Electrons reduced GO and holes adsorbed corresponding negative ions, which changed the properties of the composite film. This film was directly used as gas-sensor and was able to display high sensitivity in detecting ethanol gas. More interestingly, on the basis of SnO2-induced photochemical behaviours, this sensor demonstrated tunable sensitivity when UV irradiation time was controlled during the fabrication process and post in water, respectively. This study provides efficient ways of conducting the in situ fabrication of a semiconductor-reduced graphite oxide film device with uniform surface structure and controllable properties. PMID:25758292

Xu, Shipu; Sun, Fengqiang; Yang, Shumin; Pan, Zizhao; Long, Jinfeng; Gu, Fenglong

2015-01-01

436

Fabrication of SnO2-Reduced Graphite Oxide Monolayer-Ordered Porous Film Gas Sensor with Tunable Sensitivity through Ultra-Violet Light Irradiation  

PubMed Central

A new graphene-based composite structure, monolayer-ordered macroporous film composed of a layer of orderly arranged macropores, was reported. As an example, SnO2-reduced graphite oxide monolayer-ordered macroporous film was fabricated on a ceramic tube substrate under the irradiation of ultra-violet light (UV), by taking the latex microsphere two-dimensional colloid crystal as a template. Graphite oxide sheets dispersed in SnSO4 aqueous solution exhibited excellent affinity with template microspheres and were in situ incorporated into the pore walls during UV-induced growth of SnO2. The growing and the as-formed SnO2, just like other photocatalytic semiconductor, could be excited to produce electrons and holes under UV irradiation. Electrons reduced GO and holes adsorbed corresponding negative ions, which changed the properties of the composite film. This film was directly used as gas-sensor and was able to display high sensitivity in detecting ethanol gas. More interestingly, on the basis of SnO2-induced photochemical behaviours, this sensor demonstrated tunable sensitivity when UV irradiation time was controlled during the fabrication process and post in water, respectively. This study provides efficient ways of conducting the in situ fabrication of a semiconductor-reduced graphite oxide film device with uniform surface structure and controllable properties. PMID:25758292

Xu, Shipu; Sun, Fengqiang; Yang, Shumin; Pan, Zizhao; Long, Jinfeng; Gu, Fenglong

2015-01-01

437

Fabrication of SnO2-Reduced Graphite Oxide Monolayer-Ordered Porous Film Gas Sensor with Tunable Sensitivity through Ultra-Violet Light Irradiation  

NASA Astrophysics Data System (ADS)

A new graphene-based composite structure, monolayer-ordered macroporous film composed of a layer of orderly arranged macropores, was reported. As an example, SnO2-reduced graphite oxide monolayer-ordered macroporous film was fabricated on a ceramic tube substrate under the irradiation of ultra-violet light (UV), by taking the latex microsphere two-dimensional colloid crystal as a template. Graphite oxide sheets dispersed in SnSO4 aqueous solution exhibited excellent affinity with template microspheres and were in situ incorporated into the pore walls during UV-induced growth of SnO2. The growing and the as-formed SnO2, just like other photocatalytic semiconductor, could be excited to produce electrons and holes under UV irradiation. Electrons reduced GO and holes adsorbed corresponding negative ions, which changed the properties of the composite film. This film was directly used as gas-sensor and was able to display high sensitivity in detecting ethanol gas. More interestingly, on the basis of SnO2-induced photochemical behaviours, this sensor demonstrated tunable sensitivity when UV irradiation time was controlled during the fabrication process and post in water, respectively. This study provides efficient ways of conducting the in situ fabrication of a semiconductor-reduced graphite oxide film device with uniform surface structure and controllable properties.

Xu, Shipu; Sun, Fengqiang; Yang, Shumin; Pan, Zizhao; Long, Jinfeng; Gu, Fenglong

2015-03-01

438

Decolorization of triphenylmethane dyes and textile and dye-stuff effluent by Kurthia sp  

Microsoft Academic Search

A number of soil and water samples were collected from the vicinity of effluent treatment plant of a textile and dyeing industry. Several organisms were screened for their ability to decolorize triphenylmethane group of dyes. A Kurthia sp. was selected on the basis of rapid dye decolorizing activity. Under aerobic conditions, 98% color was removed intracellularly by this strain. A

Rajesh Kumar Sani; Uttam Chand Banerjee

1999-01-01

439

The wash-off of reactive dyes on cellulosic fibres part 2. Monochlorotriazinyl dyes on cotton  

Microsoft Academic Search

One monochlorotriazinyl and two bis-monochlorotriazinyl dyes were applied to cotton fabric at 1, 2 and 4 % omf and the dyeings then washed-off using tap water, sodium carbonate and five commercial surfactants, the latter in both the presence and absence of sodium carbonate. The concentration of sodium carbonate was varied and its effects on both the extent of dye removal

S. M. Burkinshaw; D. Katsarelias

1997-01-01

440

Compact high flow dye cell for laser-pumped dye lasers  

SciTech Connect

The rotor of a split-pole asynchronous motor is used to circulate a dye solution in a cylindrical dye cell. A compact high flow dye cell which is suitable for high repetition rate (>100 Hz ) pumping has been thus developed.

Stankov, K.A.

1988-04-01

441

Photostability of low cost dye-sensitized solar cells based on natural and synthetic dyes  

NASA Astrophysics Data System (ADS)

This paper deals with the use of some natural pigments as well as synthetic dyes to act as sensitizers in dye-sensitized solar cells (DSSCs). Anthocyanin dye extracted from rosella (Hibiscus sabdariffa L.) flowers, the commercially available textile dye Remazole Red RB-133 (RR) and merocyanin-like dye based on 7-methyl coumarin are tested. The photostability of the three dyes is investigated under UV-Vis light exposure. The results show a relatively high stability of the three dyes. Moreover, the photostability of the solid dyes is studied over the TiO2 film electrodes. A very low decolorization rates are recorded as; rate constants k = 1.6, 2.1 and 1.9 × 10-3 min-1 for anthocyanin, RR and coumarin dyes, respectively. The stability results favor selecting anthocyanin as a promising sensitizer candidate in DSSCs based on natural products. Dyes-sensitized solar cells are fabricated and their conversion efficiency (?) is 0.27%, 0.14% and 0.001% for the anthocyanin, RR and coumarin dyes, respectively. Moreover, stability tests of the sealed cells based on anthocyanin and RR dyes are done under continuous light exposure of 100 mW cm-2, reveals highly stable DSSCs.

Abdou, E. M.; Hafez, H. S.; Bakir, E.; Abdel-Mottaleb, M. S. A.

2013-11-01

442

Preliminary investigation of the effects of dye concentration on the output of a multiwavelength dye laser  

NASA Technical Reports Server (NTRS)

The effects of dye concentration on the output wavelength and energy of a multiwavelength dye laser were investigated. The dyes tested were Coumarin 2 in methyl alcohol and Rhodomine 6G, Acridine Red, and 7-diethylamino-4-methyl Coumarin (7DA 4MC) in ethyl alcohol.

Clark, I. O.; Burney, L. G.

1974-01-01

443

Photostability of low cost dye-sensitized solar cells based on natural and synthetic dyes.  

PubMed

This paper deals with the use of some natural pigments as well as synthetic dyes to act as sensitizers in dye-sensitized solar cells (DSSCs). Anthocyanin dye extracted from rosella (Hibiscus sabdariffa L.) flowers, the commercially available textile dye Remazole Red RB-133 (RR) and merocyanin-like dye based on 7-methyl coumarin are tested. The photostability of the three dyes is investigated under UV-Vis light exposure. The results show a relatively high stability of the three dyes. Moreover, the photostability of the solid dyes is studied over the TiO2 film electrodes. A very low decolorization rates are recorded as; rate constants k=1.6, 2.1 and 1.9×10(-3)min(-1) for anthocyanin, RR and coumarin dyes, respectively. The stability results favor selecting anthocyanin as a promising sensitizer candidate in DSSCs based on natural products. Dyes-sensitized solar cells are fabricated and their conversion efficiency (?) is 0.27%, 0.14% and 0.001% for the anthocyanin, RR and coumarin dyes, respectively. Moreover, stability tests of the sealed cells based on anthocyanin and RR dyes are done under continuous light exposure of 100mWcm(-2), reveals highly stable DSSCs. PMID:23832227

Abdou, E M; Hafez, H S; Bakir, E; Abdel-Mottaleb, M S A

2013-11-01

444

Local thermal resonance control of GaInP photonic crystal membrane cavities using ambient gas cooling  

E-print Network

We perform a spatially dependent tuning of a GaInP photonic crystal cavity using a continuous wave violet laser. Local tuning is obtained by laser heating of the photonic crystal membrane. The cavity resonance shift is measured for different pump positions and for two ambient gases: helium and nitrogen. The use of high-conducting gas in combination with low-conducting semiconductor leads to a resonance control with a spatial resolution better than 4 microns.

Sokolov, Sergei; Yüce, Emre; Combrié, Sylvain; Lehoucq, Gaelle; De Rossi, Alfredo; Mosk, Allard P

2015-01-01

445

21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Dye and chemical solution stains. 864.1850 Section 864.1850 Food...HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

2012-04-01

446

21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Dye and chemical solution stains. 864.1850 Section 864.1850 Food...HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

2013-04-01

447

21 CFR 864.1850 - Dye and chemical solution stains.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Dye and chemical solution stains. 864.1850 Section 864.1850 Food...HEMATOLOGY AND PATHOLOGY DEVICES Biological Stains § 864.1850 Dye and chemical solution stains. (a) Identification. Dye and...

2014-04-01

448

Chromonic liquid crystals: properties and applications as functional materials.  

PubMed

Chromonic liquid crystals (or chromonics) are formed by the self-organization of aromatic compounds with ionic or hydrophilic groups in aqueous solutions. This review summarizes the research on chromonic liquid crystals in the last two decades. The research embraced the studies of commercially available chromonic dyes and drugs, the syntheses and investigations of molecularly designed mesogens, the invention of novel processes for aligning chromonic liquid crystals, and the development of new applications as functional materials and biosensors. PMID:18536789

Tam-Chang, Suk-Wah; Huang, Liming

2008-05-01

449

Photo-alignment of liquid crystals in micro capillaries with point-by-point irradiation  

NASA Astrophysics Data System (ADS)

A photo-alignment method for micro capillaries based on the SD-1 azo-dye is demonstrated. In this work a liquid-crystal molecules aligning layer is created by point-by-point irradiation of the azo-dye film by using an UV laser light. The method opens up new possibilities for an improved molecules' orientation control in both glass- and polymer-based photonic liquid crystal fibres.

Siarkowska, A.; Jó?wik, M.; Ertman, S.; Woli?ski, T. R.; Chigrinov, V. G.

2014-09-01

450

Thiophene-based dyes for probing membranes.  

PubMed

We report the synthesis of four new cationic dipolar push-pull dyes, together with an evaluation of their photophysical and photobiological characteristics pertinent to imaging membranes by fluorescence and second harmonic generation (SHG). All four dyes consist of an N,N-diethylaniline electron-donor conjugated to a pyridinium electron-acceptor via a thiophene bridge, with either vinylene (-CH[double bond, length as m-dash]CH-) or ethynylene (-C[triple bond, length as m-dash]C-) linking groups, and with either singly-charged or doubly-charged pyridinium terminals. The absorption and fluorescence behavior of these dyes were compared to a commercially available fluorescent membrane stain, the styryl dye FM4-64. The hyperpolarizabilities of all dyes were compared using hyper-Rayleigh scattering at 800 nm. Cellular uptake, localization, toxicity and phototoxicity were evaluated using tissue cell cultures (HeLa, SK-OV-3 and MDA-231). Replacing the central alkene bridge of FM4-64 with a thiophene does not substantially change the absorption, fluorescence or hyperpolarizability, whereas changing the vinylene-links to ethynylenes shifts the absorption and fluorescence to shorter wavelengths, and reduces the hyperpolarizability by about a factor of two. SHG and fluorescence imaging experiments in live cells showed that the doubly-charged thiophene dyes localize in plasma membranes, and exhibit lower internalization rates compared to FM4-64, resulting in less signal from the cell cytosol. At a typical imaging concentration of 1 ?M, the doubly-charged dyes showed no significant light or dark toxicity, whereas the singly-charged dyes are phototoxic even at 0.5 ?M. The doubly-charged dyes showed phototoxicity at concentrations greater than 10 ?M, although they do not generate singlet oxygen, indicating that the phototoxicity is type I rather than type II. The doubly-charged thiophene dyes are more effective than FM4-64 as SHG dyes for live cells. PMID:25703541

López-Duarte, Ismael; Chairatana, Phoom; Wu, Yilei; Pérez-Moreno, Javier; Bennett, Philip M; Reeve, James E; Boczarow, Igor; Kaluza, Wojciech; Hosny, Neveen A; Stranks, Samuel D; Nicholas, Robin J; Clays, Koen; Kuimova, Marina K; Anderson, Harry L

2015-03-11

451

Optimization of nanoparticle structure for improved conversion efficiency of dye solar cell  

NASA Astrophysics Data System (ADS)

Heavy dye loading and the ability to contain the light within the thin layer (typically ˜12 ?m) are the requirement needed for the photoelectrode material in order to enhance the harvesting efficiency of dye solar cell. This can be realized by optimizing the particle size with desirable crystal structure. The paper reports the investigation on the dependency of the dye loading and light scattering on the properties of nanostructured photoelectrode materials by comparing 4 different samples of TiO2 in the form of nanoparticles and micron-sized TiO2 aggregates which composed of nanocrystallites. Their properties were evaluated by using scanning electron microscopy, X-ray diffraction and UVVis spectroscopy while the performance of the fabricated test cells were measured using universal photovoltaic test system (UPTS) under 1000 W/cm2 intensity of radiation. Nano sized particles provide large surface area which allow for greater dye adsorption but have no ability to retain the incident light in the TiO2 film. In contrast, micron-sized particles in the form of aggregates can generate light scattering allowing the travelling distance of the light to be extended and increasing the interaction between the photons and dye molecules adsorb on TiO2nanocrystallites. This resulted in an improvement in the conversion efficiency of the aggregates that demonstrates the close relation between light scattering effect and the structure of the photolectrode film.

Mohamed, Norani Muti; Zaine, Siti Nur Azella

2014-10-01

452

Optimization of nanoparticle structure for improved conversion efficiency of dye solar cell  

SciTech Connect

Heavy dye loading and the ability to contain the light within the thin layer (typically ?12 ?m) are the requirement needed for the photoelectrode material in order to enhance the harvesting efficiency of dye solar cell. This can be realized by optimizing the particle size with desirable crystal structure. The paper reports the investigation on the dependency of the dye loading and light scattering on the properties of nanostructured photoelectrode materials by comparing 4 different samples of TiO{sub 2} in the form of nanoparticles and micron-sized TiO{sub 2} aggregates which composed of nanocrystallites. Their properties were evaluated by using scanning electron microscopy, X-ray diffraction and UVVis spectroscopy while the performance of the fabricated test cells were measured using universal photovoltaic test system (UPTS) under 1000 W/cm{sup 2} intensity of radiation. Nano sized particles provide large surface area which allow for greater dye adsorption but have no ability to retain the incident light in the TiO{sub 2} film. In contrast, micron-sized particles in the form of aggregates can generate light scattering allowing the travelling distance of the light to be extended and increasing the interaction between the photons and dye molecules adsorb on TiO{sub 2}nanocrystallites. This resulted in an improvement in the conversion efficiency of the aggregates that demonstrates the close relation between light scattering effect and the structure of the photolectrode film.

Mohamed, Norani Muti, E-mail: noranimuti-mohamed@petronas.com.my [Centre of Innovative Nanostructure and Nanodevices, Universiti Teknologi PETRONAS, Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Zaine, Siti Nur Azella, E-mail: ct.azella@gmail.com.my [Fundamental and Applied Sciences Department, Universiti Teknologi PETRONAS, Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

2014-10-24

453

Hyperbranched quasi-1D nanostructures for solid-state dye-sensitized solar cells.  

PubMed

In this work we demonstrate hyperbranched nanostructures, grown by pulsed laser deposition, composed of one-dimensional anatase single crystals assembled in arrays of high aspect ratio hierarchical mesostructures. The proposed growth mechanism relies on a two-step process: self-assembly from the gas phase of amorphous TiO2 clusters in a forest of tree-shaped hierarchical mesostructures with high aspect ratio; oriented crystallization of the branches upon thermal treatment. Structural and morphological characteristics can be optimized to achieve both high specific surface area for optimal dye uptake and broadband light scattering thanks to the microscopic feature size. Solid-state dye sensitized solar cells fabricated with arrays of hyperbranched TiO2 nanostructures on FTO-glass sensitized with D102 dye showed a significant 66% increase in efficiency with respect to a reference mesoporous photoanode and reached a maximum efficiency of 3.96% (among the highest reported for this system). This result was achieved mainly thanks to an increase in photogenerated current directly resulting from improved light harvesting efficiency of the hierarchical photoanode. The proposed photoanode overcomes typical limitations of 1D TiO2 nanostructures applied to ss-DSC and emerges as a promising foundation for next-generation high-efficiency solid-state devices comprosed of dyes, polymers, or quantum dots as sensitizers. PMID:24180577

Passoni, Luca; Ghods, Farbod; Docampo, Pablo; Abrusci, Agnese; Martí-Rujas, Javier; Ghidelli, Matteo; Divitini, Giorgio; Ducati, Caterina; Binda, Maddalena; Guarnera, Simone; Li Bassi, Andrea; Casari, Carlo Spartaco; Snaith, Henry J; Petrozza, Annamaria; Di Fonzo, Fabio

2013-11-26

454

Theory of pulsed dye lasers including dye-molecule rotational relaxation  

SciTech Connect

In this paper a phenomenological semiclassical theory of pulsed-laser-pumped dye-laser light amplifiers is presented. The theory accounts for the broadband radiation absorption and emission characteristics of dye molecules in liquid solvents. Dye-molecule fluorescence, vibrational, rotational, and electric polarization relaxation processes are represented by phenomenological relaxation rates. In general, it is found that due to dye-molecule rotational relaxation the laser-pumped dye medium is optically anisotropic. The pump- and dye-laser beams propagate through the dye medium as essentially transverse electromagnetic waves whose amplitude and polarization state changes. The theory is applicable to pulse durations {tau}{approx lt}10--100 ns including the ultrashort pulse regime. The regime {tau}{approx gt}1 ps in which the pump- and dye-laser pulse lengths are long compared to the dye-molecule vibrational and electric polarization relaxation times is considered in detail. Amplification of partially polarized quasimonochromatic light is described by a self-consistent set of equations for the components of the pump- and dye-laser light coherency matrices and the orientation populations of the lowest vibronic levels of the dye molecule's {ital S}{sub 0} and {ital S}{sub 1} electronic states.

Haas, R.A.; Rotter, M.D. (Department of Applied Science, University of California, Davis-Livermore, L-794, P.O. Box 808, Livermore, California 94550 (US) Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550)

1991-02-01

455

Dyeing behaviour of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves (Lawsonia inermis)  

NASA Astrophysics Data System (ADS)

Dyeing behavior of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves has been investigated. Cotton and dye powder are irradiated to different absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. The dyeing parameters such as dyeing time, electrolyte (salt) concentration and mordant concentrations using copper and iron as mordants are optimized. Dyeing is performed using un-irradiated and irradiated cotton with dye solutions and their color strength values are evaluated in CIE Lab system using Spectraflash -SF650. Methods suggested by International Standard Organization (ISO) have been employed to investigate the colourfastness properties such as colourfastness to light, washing and rubbing of irradiated dyed fabric. It is found that gamma ray treatment of cotton dyed with extracts of henna leaves has significantly improved the color strength as well as enhanced the rating of fastness properties.

Rehman, Fazal-ur; Adeel, Shahid; Qaiser, Summia; Ahmad Bhatti, Ijaz; Shahid, Muhammad; Zuber, Mohammad

2012-11-01

456

Fate of commercial disperse dyes in sediments  

SciTech Connect

Kinetics of disappearance of seven different disperse dyes were determined in compacted sediments at room temperature. The commercial dyes (in dispersed solid form) were representative of nitroazo, anthraquinone, and quinoline structures that are widely used. Reaction rates were found to be first order over at least two half-lives and were different for the three groups of dyes. Half-lives were on the order of hours, days and months for the nitroazobenzene, aminoanthraquinone, and quinoline dyes, respectively. Stability of the latter is consistent with detection of a quinoline dye in treatment plant sludge and in sediment from a water body receiving treated effluent. The azobenzene dyes are degraded by cleavage of the azo group to give anilines and ring-substituted phenylenediamines from the diazo component of the molecule. Products from the other portion (coupling component) of the molecule are unidentified, as yet, but are expected to be N,N-disubstituted phenylenediamines. Products of the anthraquinone dyes were unidentified, except for the case of a nitrated dye on which the nitro group was reduced.

Yen, C.P.C.; Perenich, T.A.; Baughman, G.L.

1991-01-01

457

Aromatic amines: use in azo dye chemistry.  

PubMed

This chapter provides an overview of the chemical structures and properties of aromatic amines and their role in the development and utility of azo dyes. Approaches to the design of environmentally benign alternatives to genotoxic primary aromatic amines, as azo dye precursors, are included. PMID:23276915

Freeman, Harold S

2013-01-01

458

Modeling of dye-laser photon statistics  

Microsoft Academic Search

We propose a model for dye lasers operating at resonance with a non-Gaussian fluctuating pump parameter. Analytical and numerical results are compared with recent experimental measurements on the intensity fluctuations of a dye laser and with previous theoretical predictions based on a fluctuating pump parameter of finite correlation time.

Fabio Marchesoni; Theoretische Physik

1986-01-01

459

Dye laser chain for laser isotope separation  

Microsoft Academic Search

Uranium enrichment by laser isotope separation uses a three step operation which requires four visible wavelengths to boost an individual U235 isotope from a low lying atomic energy level to an autoionizing state. The visible wavelengths are delivered by dye lasers pumped by copper vapor lasers (CVL). In this particular talk, a single dye chain consisting of a master oscillator

Denis Doizi; Jean Jaraudias; E. Pochon; G. Salvetat

1993-01-01

460

Fluorescence efficiency of four infrared polymethine dyes  

Microsoft Academic Search

We report on the fluorescence efficiency of four infrared (IR) polymethine dyes. These figures have been determined using an indirect method based on a fluorescence standard (Rhodamine B in ethanol). The fluorescence decay times have been measured too and their correlation with the quantum efficiency data has been shown. The optical behavior of the IR dyes in three solvents with

M. Casalboni; F. De Matteis; P. Prosposito; A. Quatela; F. Sarcinelli

2003-01-01

461

ORGANIC DYES AND PIGMENTS DATA BASE  

EPA Science Inventory

The objective of this research program was to compile a data base covering all the commercially significant dyes and pigments produced or imported in the United States. The Organic Dyes and Pigments Data Base (ODPDB) contains the following data elements: chemical-related data (co...

462

Fungal decolorization of dye wastewaters: a review  

Microsoft Academic Search

In recent years, there has been an intensive research on fungal decolorization of dye wastewater. It is becoming a promising alternative to replace or supplement present treatment processes. This paper examines various fungi, living or dead cells, which are capable of decolorizing dye wastewaters; discusses various mechanisms involved; reports some elution and regeneration methods for fungal biomass; summarizes the present

Yuzhu Fu; T Viraraghavan

2001-01-01

463

Dye biosorption sites in Aspergillus niger  

Microsoft Academic Search

Aspergillus niger is capable of removing dyes from an aqueous solution. In the study, the roles played by three major functional groups: carboxyl, amino and phosphate, and the lipid fraction in the biomass of A. niger in biosorption of four dyes, Basic Blue 9, Acid Blue 29, Congo Red and Disperse Red 1, were investigated. These functional groups in A.

Yuzhu Fu; T Viraraghavan

2002-01-01

464

Solid state dye laser for medical applications  

Microsoft Academic Search

The development of solid state dye lasers could lead to a major breakthrough in the cost and compactness of a medical device. Advantages include: elimination of the flow system for the gain medium; ease with which to implement wavelength agility or the replacement of a degraded rod or sheet; and toxicity and flammability become a non-issue. Dye lasers have played

Henry R. Aldag

1994-01-01

465

Use of slag for dye removal  

SciTech Connect

Adsorption techniques employing activated carbon have been found to be reasonably effective in the removal of some of the ionic impurities in water. However, economic considerations may require the use of inexpensive sorbents which are either naturally available or available as waste products from manufacturing processes. Slag is one such waste product obtained during the manufacture of steel, and the present study investigates dye removal characteristics of slag from colored waters. Aqueous solutions prepared from commercial grade acid, basic, and disperse dyes were used in this study, and batch pH, kinetic, and isotherm studies were undertaken on a laboratory scale. The data were evaluated for applicability to the Langmuir, Freundlich, and BET isotherm models, and the removal capacity of slag was compared with that of granular activated carbon. Results indicated approximately 94% removal of the disperse dye by slag, compared with a removal of approximately 49% achieved by activated carbon. Removal of acid dyes (dyes containing anionic groups) was reasonably good (approximately 47 and 74%), though not as good as obtained using activated carbon (approximately 100%). Column studies were conducted with a disperse dye (nonionic, slightly soluble in water), and analysis of data showed a sorption capacity of 1.3 mg of disperse dye per gram of slag. However, effluent dye concentrations were found to be higher than the permissible levels for discharge to receiving waters.

Ramakrishna, K.R.; Viraraghavan, T. [Univ. of Regina, Saskatchewan (Canada). Faculty of Engineering

1998-09-01

466

Curious Crystals  

NSDL National Science Digital Library

Learners carefully look at four known household crystals. After observing and describing the crystals, learners are given an unknown crystal, which is chemically the same as one of the four known crystals but looks different. When learners realize that they cannot identify this crystal by its appearance alone, they will suggest other tests and ways to compare the crystals to eventually identify the unknown crystal. The related activities are examples of tests learners can conduct on the crystals. After a series of these tests, learners will gather enough evidence to identify the unknown crystal.

James H. Kessler

2007-01-01

467

Synthesis, characterization and antimicrobial studies of 2-{(E)-[(2-hydroxy-5-methylphenyl)imino]methyl}-4-[(E)-phenyldiazenyl]phenol as a novel azo-azomethine dye  

NASA Astrophysics Data System (ADS)

A novel dye, 2-{(E)-[(2-hydroxy-5-methylphenyl)imino]methyl}-4-[(E)-phenyldiazenyl]phenol dye was synthesized by the condensation reaction of 2-hydroxy-5-[(E)-phenyldiazenyl]benzaldehyde with 2-amino-4-methylphenol in methanol. The title dye was characterized by its melting point, elemental analysis, FT-IR, 1H, 13C NMR and mass spectroscopic studies. Molecular structure of the title dye was determined by single crystal X-ray diffraction study. X-ray data showed that the dye crystallizes in the monoclinic space group P21/c with cell parameters a = 18.541(2) Å, b = 4.7091(5) Å, c = 20.586(2) Å, V = 1761.5(3) Å3 and Z = 4. The title dye adopts azo-enamine tautomer in the solid state. The molecules crystallises as dimers assembled by two molecules of methanol via intermolecular hydrogen bonding resulting in R64(18) hydrogen bonding motif. Additionally, there is an intramolecular keto-amine hydrogen bond (NH⋯O) with a distance of 2.6172(17) Å. Optimized structures of the three possible tautomers of the compound were obtained using B3LYP method with 6-311++G(d,p), 6-31G and 3-21G basis sets in the gas phase. Thermal properties of the prepared dye were examined by thermogravimetric analysis and results indicated that the framework of the dye is stable up to 172 °C. Furthermore, the pathogenic activities of the synthesized dye were tested in vitro against the sensitive organisms, Bacillus cereous (ATCC 33019) and Staphylococcus aureus (ATCC 25923) as gram positive bacteria, Escherichia coli (ATCC 11229), and Klebsiella pneumoniae (ATCC 13883) as gram negative bacteria and the results are discussed. The results indicated that the prepared dye had antibacterial activities against gram-positive bacteria (S. aureus and Bacillus cereuss), but it exhibited no activity against gram-negative bacteria (E. coli and K. pneumoniae).

Köse, Muhammet; Kurtoglu, Nurcan; Gümü?su, Özkan; Tutak, Mustafa; McKee, Vickie; Karaka?, Duran; Kurtoglu, Mukerrem

2013-12-01

468

Photolysis of smoke dyes on soils  

SciTech Connect

Photolysis of an azo, a quinophthalone, and several anthraquinone smoke dyes was studied on soil surfaces. Initially, rapid photodegradation of each dye occurred, followed by a period of much slower rate of loss, indicating that the remaining fraction of the dye was photochemically protected. The average mean depths of photolysis ranged from 0.33 to 0.68 mm for outdoor studies and from 0.42 to 0.73 mm for lab studies. The magnitude of the mean depths of photolysis suggests that photo-degradation of the dyes occurs through indirect photochemical processes. Photolysis products for only two of the dyes could be identified. Photolysis of Disperse Red 9 resulted in the formation of 1-aminoanthraquinone, whereas Solvent Yellow 33 photo-degraded to give 2-carboxyquinoline and phthalic anhydride. Reaction mechanisms involving sensitized photo-oxidation by singlet oxygen are consistent with the formation of these reaction products.

Adams, R.L. (Technology Applications Inc., Athens, GA (United States). Environmental Research Lab.); Weber, E.J.; Baughman, G.L. (Environmental Protection Agency, Athens, GA (United States). Environmental Research Lab.)

1994-06-01

469

Selective photochromic dye patterning using spiroxazine compound.  

PubMed

We have studied a selective dye patterning system using light stamping lithography (LSL) method, where the photochromic colorant was applied to confirm the prepared micro patterns. The steps of this process consist of substrate (glass slide) preparation, polydimethylsiloxane (PDMS) transfer and final photochromic dye deposition on the patterns. To determine the designed pattern images, the photochromic spiroxazine compound having rapid color absorption and desirable light fastness properties was selected and synthesized. The resulting deposition characteristics of this spiroxazine dye pattern were characterized using UV-spectrophotometer and image analysis. It is proposed that this selective photochromic dye pattern was obtained by physical and hydrophobic interactions between PDMS mold and spiroxazine molecules. This fabricated spiroxazine dye patterns show a good response with repeated UV light stimuli and visible light on-off test. PMID:19198458

Lee, Chang-Soo; Park, Young-Min; Kim, Bo-Yeol; Son, Young-A

2008-10-01

470

Dye removal by surfactant encapsulated polyoxometalates.  

PubMed

A novel surfactant encapsulated polyoxometalate (SEP) has been synthesized by using a simple ion-exchange reaction. The prepared SEP complex was found to self-assemble into nanospherical particles whose morphology and component were characterized by TEM and XPS. The SEP was further incorporated into polyvinylidene fluoride (PVDF) to fabricate SEP incorporated composite membrane (SEP-M). Both the SEP and SEP-M exhibited excellent dye removal activities, which is for the first time reported as an intriguing property of the SEP. A regeneration scheme for SEP-M was successfully proposed without any loss of dye removal efficiency. Detailed mechanism studies were carried out to elucidate the nature of dye decolorization. Ion exchange was revealed to play a dominant role in the dye removal process. The current research not only renders a new example for the simple and direct synthesis of SEP but more importantly provides an efficient dye removal methodology. PMID:25194560

Yao, Lei; Lua, Shun Kuang; Zhang, Lizhi; Wang, Rong; Dong, ZhiLi

2014-09-15

471

Random lasing in liquid and solid solutions oversaturated with organic laser dye  

NASA Astrophysics Data System (ADS)

We present the results of studies carried out for oversaturated solutions with common laser dye 4- (Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) and 3-(1,1-Dicyanoethenyl)-1-phenyl-4,5- dihydro-1H-pyrazole (DCNP) nonlinear chromophore. We show that oversaturating the solution leads to formation of crystals suspension resulting in strong Mie scattering and thus random laser operation can be observed. The formation of aggregates can be induced be oversaturating the solution or by injection of non-solvent to the dye solution, leading to reduction of solubility limit. Similar situation can be obtained for polymeric matrices for which small crystals are precipitated during layer formation (solvent evaporation) when film is casted from the solution.

Sznitko, Lech; Cyprych, Konrad; Szukalski, Adam; Miniewicz, Andrzej; Mysliwiec, Jaroslaw

2014-03-01

472

Multicolor fluorescence enhancement from a photonics crystal surface  

NASA Astrophysics Data System (ADS)

A photonic crystal substrate exhibiting resonant enhancement of multiple fluorophores has been demonstrated. The device, fabricated uniformly from plastic materials over a ˜3×5 in.2 surface area by nanoreplica molding, utilizes two distinct resonant modes to enhance electric field stimulation of a dye excited by a ? =632.8 nm laser (cyanine-5) and a dye excited by a ? =532 nm laser (cyanine-3). Resonant coupling of the laser excitation to the photonic crystal surface is obtained for each wavelength at a distinct incident angle. Compared to detection of a dye-labeled protein on an ordinary glass surface, the photonic crystal surface exhibited a 32× increase in fluorescent signal intensity for cyanine-5 conjugated streptavidin labeling, while a 25× increase was obtained for cyanine-3 conjugated streptavidin labeling. The photonic crystal is capable of amplifying the output of any fluorescent dye with an excitation wavelength in the 532