Fixed-bed adsorption study of methylene blue onto pyrolytic tire char

NASA Astrophysics Data System (ADS)

Makrigianni, Vassiliki; Giannakas, Aris; Papadaki, Maria; Albanis, Triantafyllos; Konstantinou, Ioannis

2016-04-01

In this work, the adsorption efficiency of acid treated pyrolytic tire char to cationic methylene blue (MB) dye adsorption from aqueous solutions was investigated by fixed-bed adsorption column experiments. The effects of the initial dye concentration (10 - 40 mg L-1) and feed flow rate (50 - 150 mL min -1) with a fixed bed height (15 cm) were studied in order to determine the breakthrough characteristics of the adsorption system. The Adams-Bohart, Yoon-Nelson and Thomas model were applied to the adsorption of MB onto char at different operational conditions to predict the breakthrough curves and to determine the characteristic parameters of the column. The results showed that the maximum adsorbed quantities decreased with increasing flow rate and increased with increasing initial MB concentration. Breakthrough time and exhaustion time increased with decreasing inlet dye concentration and flow rate. In contrast with Adams-Bohart model, Yoon-Nelson model followed by Thomas model were found more suitable to describe the fixed-bed adsorption of methylene blue by char. The correlation coefficient values R2 for both models at different operating conditions are higher than 0.9 and the low average relative error values provided very good fittings of experimental data at different operating conditions. Higher adsorption capacity of 3.85 mg g -1 was obtained at 15 cm of adsorbent bed height, flow rate of 100 mL min -1and initial MB concentration of 40 mg L-1. Although that activated carbons exhibited higher adsorption capacities in the literature, acid-treated pyrolytic tire char was found to be considerably efficient adsorbent for the removal of MB dye column taking into account the advantages of the simpler production process compared to activated carbons, as well as, the availability of waste tire feedstock and concurrent waste tire management.

Influence of macroporosity on preferential solute and colloid transport in unsaturated field soils.

PubMed

Cey, Edwin E; Rudolph, David L; Passmore, Joanna

2009-06-26

Transport of solutes and colloids in soils, particularly those subject to preferential flow along macropores, is important for assessing the vulnerability of shallow groundwater to contamination. The objective of this study was to investigate flow and transport phenomena for dissolved and colloid tracers during large infiltration events in partially saturated, macroporous soils. Controlled tracer infiltration tests were completed at two field sites in southern Ontario. A tension infiltrometer (TI) was used to infiltrate water with dissolved Brilliant Blue FCF dye simultaneously with 3.7 microm and 0.53 microm diameter fluorescent microspheres. Infiltration was conducted under maximum infiltration pressure heads ranging from -5.2 to -0.4 cm. All infiltration test sites were excavated to examine and photograph dye-stained flow patterns, map soil features, and collect samples for microsphere enumeration. Results indicated that preferential transport of dye and microspheres via macropores occurred when maximum pressure heads were greater than -3.0 cm, and the corresponding infiltration rates exceeded 2.0 cm h(-1). Dye and microspheres were detected at depths greater than 70 cm under the highest infiltration rates from both sites. Microsphere concentrations in the top 5-10 cm of soil decreased by more than two orders of magnitude relative to input concentrations, yet remained relatively constant with depth thereafter. There was some evidence for increased retention of the 3.7 microm microspheres relative to the 0.53 microm microspheres, particularly at lower infiltration pressures where straining and attachment mechanisms are most prevalent. Microspheres were observed within dye stained soil matrix surrounding individual macropores, illustrating the significance of capillary pressures in controlling the vertical migration of both tracers in the vicinity of the macropores. Overall, microsphere distributions closely followed the dye patterns, with microsphere concentrations at all depths directly related to the intensity (or concentration) of dye staining. It is concluded that the flow system influenced transport to a much greater degree than differences between dissolved and colloidal species, and hence a dye tracer could serve as a reasonable surrogate for colloid distributions in the vadose zone following individual infiltration events.

Determination of fast ozone oxidation rate for textile dyes by using a continuous quench-flow system.

PubMed

Gomes, Arlindo C; Nunes, José C; Simões, Rogério M S

2010-06-15

To study the fast kinetic decolourisation of textile dyes by ozone a continuous quench-flow system was used. This system has not been used before for these purposes. Reaction times in the range of 7-3000 ms were explored. The reaction was quenched with potassium iodide, which proved to be very effective, and the indigo method was used to follow the ozone concentration. Dyes from the most representative chemical classes currently used in the textile industry, i.e. azo and anthraquinone, were selected. Using the initial slope method, the effect of dye and ozone concentrations was researched and the kinetic equations thus established. Using tert-butyl alcohol, as radical scavenger, and pH close to 2.5, the second-order rate constant of the reactant dyes at 280 K varies in the range of 1.20x10(4)-7.09x10(5)M(-1)s(-1); the Acid Orange 7 exhibiting thus its lowest value, the Acid Blue 45 its highest value and the Acid Green 25 and 27 and Direct Yellow 4 intermediate values (approximately 1.6x10(5)M(-1)s(-1)). Without radical scavenger and the pH close to 4, the reaction rate increases one order of magnitude, but, on the reverse, the efficiency of ozone to decolourisation decreases. Copyright 2010 Elsevier B.V. All rights reserved.

Automatic tracer-dilution method used for stage-discharge ratings and streamflow hydrographs on small Iowa streams

USGS Publications Warehouse

Soenksen, P.J.

1990-01-01

Tracer-dilution discharge measurements were made during 14 flow periods at six stations from 1986 through 1988 water years. Ratings were developed at three stations with the aid of these measurements. A loop rating was identified at one station during rapidly-changing flow conditions. Incomplete mixing and dye loss to sediment apparently were problems at some stations. Stage hydrographs were recorded for 38 flows at seven stations. Limited data on background fluorescence during high flows were also obtained.

Summary and interpretation of dye-tracer tests to investigate the hydraulic connection of fractures at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Kentucky

USGS Publications Warehouse

Taylor, Charles J.

1994-01-01

Dye-tracer tests were done during 1985-92 to investigate the hydraulic connection between fractures in Pennsylvanian coal-bearing strata at a ridge-and-valley-wall site near Fishtrap Lake, Pike County, Ky. Fluorescent dye was injected into a core hole penetrating near-surface and mining-induced fractures near the crest of the ridge. The rate and direction of migration of dye in the subsurface were determined by measuring the relative concentration of dye in water samples collected from piezometers completed in conductive fracture zones and fractured coal beds at various stratigraphic horizons within the ridge. Dye-concentration data and water-level measurements for each piezometer were plotted as curves on dye-recovery hydrographs. The dye-recovery hydrographs were used to evaluate trends in the fluctuation of dye concentrations and hydraulic heads in order to identify geologic and hydrologic factors affecting the subsurface transport of dye. The principal factors affecting the transport of dye in the subsurface hydrologic system were determined to be (1) the distribution, interconnection, and hydraulic properties of fractures; (2) hydraulic-head conditions in the near-fracture zone at the time of dye injection; and (3) subsequent short- and long-term fluctuations in recharge to the hydrologic system. In most of the dye-tracer tests, dye-recovery hydrographs are characterized by complex, multipeaked dye-concentration curves that are indicative of a splitting of dye flow as ground water moved through fractures. Intermittent dye pulses (distinct upward spikes in dye concentration) mark the arrivals of dye-labeled water to piezometers by way of discrete fracture-controlled flow paths that vary in length, complexity, and hydraulic conductivity. Dye injections made during relatively high- or increasinghead conditions resulted in rapid transport of dye (within several days or weeks) from near-surf ace fractures to piezometers. Injections made during relatively low- or decreasing-head conditions resulted in dye being trapped in hydraulically dead zones in water-depleted fractures. Residual dye was remobilized from storage and transported (over periods ranging from several months to about 2 years) by increased recharge to the hydrologic system. Subsequent fluctuations in hydraulic gradients, resulting from increases or decreases in recharge to the hydrologic system, acted to speed or slow the transport of dye along the fracture-controlled flow paths. The dye-tracer tests also demonstrated that mining-related disturbances significantly altered the natural fracture-controlled flow paths of the hydrologic system over time. An abandoned underground mine and subsidence-related surface cracks extend to within 250 ft of the principal dye-injection core hole. Results from two of the dye-tracer tests at the site indicate that the annular seal in the core hole was breached by subsurface propagation of the mining-induced fractures. This propagation of fractures resulted in hydraulic short-circuiting between the dye-injection zone in the core hole and two lower piezometer zones, and a partial disruption of the hydraulic connection between the injection core hole and downgradient piezometers on the ridge crest and valley wall. In addition, injected dye was detected in piezometers monitoring a flooded part of the abandoned underground mine. Dye was apparently transported into the mine through a hydraulic connection between the injection core hole and subsidence-related fractures.

Batch and fixed-bed adsorption of tartrazine azo-dye onto activated carbon prepared from apricot stones

NASA Astrophysics Data System (ADS)

Albroomi, H. I.; Elsayed, M. A.; Baraka, A.; Abdelmaged, M. A.

2017-07-01

This work describes the potential of utilizing prepared activated carbon from apricot stones as an efficient adsorbent material for tartrazine (TZ) azo-dye removal in a batch and dynamic adsorption system. The results revealed that activated carbons with well-developed surface area (774 m2/g) and pore volume (1.26 cm3/g) can be manufactured from apricot stones by H3PO4 activation. In batch experiments, effects of the parameters such as initial dye concentration and temperature on the removal of the dye were studied. Equilibrium was achieved in 120 min. Adsorption capacity was found to be dependent on the initial concentration of dye solution, and maximum adsorption was found to be 76 mg/g at 100 mg/L of TZ. The adsorption capacity at equilibrium ( q e) increased from 22.6 to 76 mg/g with an increase in the initial dye concentrations from 25 to 100 mg/L. The thermodynamic parameters such as change in free energy (Δ G 0), enthalpy (Δ H 0) and entropy (Δ S 0) were determined and the positive value of (Δ H) 78.1 (K J mol-1) revealed that adsorption efficiency increased with an increase in the process temperature. In fixed-bed column experiments, the effect of selected operating parameters such as bed depth, flow rate and initial dye concentration on the adsorption capacity was evaluated. Increase in bed height of adsorption columns leads to an extension of breakthrough point as well as the exhaustion time of adsorbent. However, the maximum adsorption capacities decrease with increases of flow rate. The breakthrough data fitted well to bed depth service time and Thomas models with high coefficient of determination, R 2 ≥ 94.

On-chip tunable optofluidic dye laser

NASA Astrophysics Data System (ADS)

Cai, Zengyan; Shen, Zhenhua; Liu, Haigang; Yue, Huan; Zou, Yun; Chen, Xianfeng

2016-11-01

We demonstrate a chip-scale tunable optofluidic dye laser with Au-coated fibers as microcavity. The chip is fabricated by soft lithography. When the active region is pumped, a relatively low threshold of 6.7 μJ/mm2 is realized with multimode emission due to good confinement of the cavity mirrors, long active region, as well as total reflectivity. It is easy to tune the lasing emission wavelength by changing the solvent of laser dye. In addition, the various intensity ratios of multicolor lasing can be achieved by controlling flow rates of two fluid streams carried with different dye molecules. Furthermore, the convenience in fabrication and directional lasing emission outcoupled by the fiber make the tunable optofluidic dye laser a promising underlying coherent light source in the integrated optofluidic systems.

Measured flow and tracer-dye data showing the anthropogenic effects on the hydrodynamics of south Sacramento-San Joaquin Delta, California, spring 1996 and 1997

USGS Publications Warehouse

Oltmann, Richard N.

1998-01-01

Tidal flows were measured using acoustic Doppler current profilers and ultrasonic velocity meters during spring 1996 and 1997 in south Sacramento-San Joaquin Delta, California, when (1) a temporary barrier was installed at the head of Old River to prevent the entrance of migrating San Joaquin River salmon smolts, (2) the rate of water export from the south Delta was reduced for an extended period of time, and (3) a 30-day pulse flow was created on the San Joaquin River to move salmon smolts north away from the export facilities during spring 1997. Tracer-dye measurements also were made under these three conditions.

Hydraulic characteristics of the New River in the New River Gorge National River, West Virginia

USGS Publications Warehouse

Wiley, J.B.; Appel, David H.

1989-01-01

Traveltime, dispersion, water-surface and streambed profiles, and cross-section data were collected for use in application of flow and solute-transport models to the New River in the New River Gorge National River, West Virginia. Dye clouds subjected to increasing and decreasing flow rates (unsteady flow) showed that increasing flows shorten the cloud and decreasing flows lengthen the cloud. After the flow rate was changed and the flow was again steady, traveltime and dispersion characteristics were determined by the new rate of flow. Seven stage/streamflow relations identified the general changes of stream geometry throughout the study reach. Channel cross sections were estimated for model input. Low water and streambed profiles were developed from surveyed water surface elevations and water depths. (USGS)

Characterizing Reactive Flow Paths in Fractured Cement

NASA Astrophysics Data System (ADS)

Wenning, Q. C.; Huerta, N. J.; Hesse, M. A.; Bryant, S. L.

2011-12-01

Geologic carbon sequestration can be a viable method for reducing anthropogenic CO2 flux into the atmosphere. However, the technology must be economically feasible and pose acceptable risk to stakeholders. One key risk is CO2 leakage out of the storage reservoir. Potential driving forces for leakage are the overpressure due to CO2 injection and the buoyancy of free phase CO2. Potential hazards of leakage are contamination of Underground Sources of Drinking Water or the atmosphere and would be deemed an unacceptable risk. Wells potentially provide a fast path for leakage from the reservoir. While the well's cement casing is reactive with CO2 and CO2-saturated brine, the low cement matrix permeability and slow diffusion rate make it unlikely that CO2 will escape through a properly constructed wellbore. However, highly permeable fractures with micrometer scale apertures can occur in cement casings. Reactions that occur in the flow in these fractures can either be self-limiting or self-enhancing. Therefore, understanding the reactive flow is critical to understanding of leakage evolution through these fractures. The goal of our work is to characterize the modification of the flow paths in the fracture due to reaction with acidic brine. With this aim we have characterized both the initial flow path of un-reactive flow and the final flow path after introduction of low-pH acid along the same fracture. Class H cement cores 3-6 cm in length and 2.5 cm diameter are created and a single natural and unique fracture is produced in each core using the Brazilian method. Our experimental fluid is injected at a constant rate into the cement core housed in a Hassler Cell under confining pressure. A solution of red dye and deionized water is pumped through the fracture to stain the un-reactive flow paths. Deionized water is then pumped through the core to limit diffusion of the dye into non-flowing portions of the fracture. After staining the initial flow path, low pH water due to hydrochloric acid (HCL), is pumped through the core at the same rate as the dye. The low pH water is used as a proxy for acidic CO2-saturated brine. Both staining from the un-reactive dye and acid produce visible permanent color alterations on the cement fracture plane. Results show that nearly the entire fracture width is stained by the red dye, with only a few asperities un-dyed. However the low pH HCl forms restricted reacted channels that are a subset of the area open to un-reactive flow, occupying only 10-50% of the entire fracture width. Low pH HCl is believed to be the driving force for the reaction that causes channeling. As acid flows through the fracture, calcium is stripped from the low pH high velocity flow front and precipitates along of the edges of the channel where pH is higher due to the lower flow velocities outside the channel. It is hypothesized that this mineral precipitation restricts the flow into localized channels within the plane of fractures having apertures of tens of micrometers. Reactions restrict the flow path to a smaller fraction of the surface, which may be an indication of self-limiting behavior.

Application of enhanced membrane bioreactor (eMBR) to treat dye wastewater.

PubMed

Rondon, Hector; El-Cheikh, William; Boluarte, Ida Alicia Rodriguez; Chang, Chia-Yuan; Bagshaw, Steve; Farago, Leanne; Jegatheesan, Veeriah; Shu, Li

2015-05-01

An enhanced membrane bioreactor (eMBR) consisting of two anoxic bioreactors (ARs) followed by an aerated membrane bioreactor (AMBR), UV-unit and a granular activated carbon (GAC) filter was employed to treat 50-100 mg/L of remazol blue BR dye. The COD of the feed was 2334 mg/L and COD:TN:TP in the feed was 119:1.87:1. A feed flow rate of 5 L/d was maintained when the dye concentration was 50 mg/L; 10 L/d of return activated sludge was recirculated to each AR from the AMBR. Once the biological system is acclimatised, 95% of dye, 99% of COD, 97% of nitrogen and 73% of phosphorus were removed at a retention time of 74.4 h. When the effluent from the AMBR was drawn at a flux rate of 6.5 L/m(2)h, the trans-membrane pressure reached 40 kPa in every 10 days. AMBR effluent was passed through the UV-unit and GAC filter to remove the dye completely. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simultaneous Preconcentration and Determination of Brilliant Blue and Sunset Yellow in Foodstuffs by Solid-Phase Extraction Combined UV-Vis Spectrophotometry.

PubMed

Bişgin, Abdullah Taner

2018-05-29

Background: Brilliant Blue and Sunset Yellow, two highly water-soluble synthetic food dyes, are the most popular food dyes used and consumed. Although they are not highly toxic, some health problems can be observed when excessive amounts of food products containing these dyes are consumed. Objectives: The aim of the study was to develop a simultaneous UV-Vis combined solid-phase extraction method, based on the adsorption onto Amberlite XAD-8 resin, for determination of Brilliant Blue and Sunset Yellow dyes. Methods: Sample solution was poured into the reservoir of the column and permitted to gravitationally pass through the column at 2 mL/min flow rate. Adsorbed dyes were eluted to 5 mL of final volume with 1 mol/L HNO₃ in ethanol solution by applying a 2 mL/min flow rate. Dye concentrations of the solution were determined at 483 and 630 nm for Sunset Yellow and Brilliant Blue, respectively. Results: The detection limits of the method for Brilliant Blue and Sunset Yellow were determined as 0.13 and 0.66 ng/mL, respectively. Preconcentration factor was 80. Brilliant Blue contents of real food samples were found to be between 11 and 240 μg/g. Sunset Yellow concentrations of foodstuffs were determined to be between 19 and 331 μg/g. Conclusions: Economical, effective, and simple simultaneous determination of Brilliant Blue and Sunset Yellow was achieved by using a solid-phase extraction combined UV-Vis spectrometry method. Highlights: The method is applicable and suitable for routine analysis in quality control laboratories without the need for expert personnel and high operational costs because the instrumentation is simple and inexpensive.

Flow visualization in long neck Helmholtz resonators with grazing flow

NASA Technical Reports Server (NTRS)

Baumeister, K. J.; Rice, E. J.

1976-01-01

Both oscillating and steady flows were applied to a single plexiglass resonator cavity with colored dyes injected in both the orifice and grazing flow field to record the motion of the fluid. For oscillatory flow, the instantaneous dye streamlines were similar for both the short and long-neck orifices. The orifice flow blockage appears to be independent of orifice length for a fixed amplitude of flow oscillation and magnitude of the grazing flow. The steady flow dye studies showed that the acoustic and steady flow resistances do not necessarily correspond for long neck orifices.

Laser velocimetry with fluorescent dye-doped polystyrene microspheres.

PubMed

Lowe, K Todd; Maisto, Pietro; Byun, Gwibo; Simpson, Roger L; Verkamp, Max; Danehy, Paul M; Tiemsin, Pacita I; Wohl, Christopher J

2013-04-15

Simultaneous Mie scattering and laser-induced fluorescence (LIF) signals are obtained from individual polystyrene latex microspheres dispersed in an air flow. Microspheres less than 1 μm mean diameter were doped with two organic fluorescent dyes, Rhodamine B (RhB) and dichlorofluorescein (DCF), intended either to provide improved particle-based flow velocimetry in the vicinity of surfaces or to provide scalar flow information (e.g., marking one of two fluid streams). Both dyes exhibit measureable fluorescence signals that are on the order of 10(-3) to 10(-4) times weaker than the simultaneously measured Mie signals. It is determined that at the conditions measured, 95.5% of RhB LIF signals and 32.2% of DCF signals provide valid laser-Doppler velocimetry measurements compared with the Mie scattering validation rate with 6.5 W of 532 nm excitation, while RhB excited with 1.0 W incident laser power still exhibits 95.4% valid velocimetry signals from the LIF channel. The results suggest that the method is applicable to wind tunnel measurements near walls where laser flare can be a limiting factor and monodisperse particles are essential.

Treatment of artificial wastewater containing two azo textile dyes by vertical-flow constructed wetlands.

PubMed

Hussein, Amjad; Scholz, Miklas

2018-03-01

The release of untreated dye textile wastewater into receiving streams is unacceptable not only for aesthetic reasons and its negative impacts on aquatic life but also because numerous dyes are toxic and carcinogenic to humans. Strategies, as of now, used for treating textile wastewaters have technical and economical restrictions. The greater part of the physico-chemical methods, which are used to treat this kind of wastewater, are costly, produce large amounts of sludge and are wasteful concerning some soluble dyes. In contrast, biological treatments such as constructed wetlands are cheaper than the traditional methods, environmental friendly and do not produce large amounts of sludge. Synthetic wastewater containing Acid Blue 113 (AB113) and Basic Red 46 (BR46) has been added to laboratory-scale vertical-flow construction wetland systems, which have been planted with Phragmites australis (Cav.) Trin. ex Steud. (common reed). The concentrations 7 and 208 mg/l were applied for each dye at the hydraulic contact times of 48 and 96 h. Concerning the low concentrations of BR46 and AB113, the unplanted wetlands are associated with significant (ρ < 0.05) reduction performances, if compared with planted wetlands concerning the removal of dyes. For the high concentrations of AB113, BR46 and a mixture of both of them, wetlands with long contact times were significantly (ρ < 0.05) better than wetlands that had short contact times in terms of dye, colour and chemical oxygen demand reductions. Regarding nitrate nitrogen (NO 3 -N), the reduction percentage rates of AB113, BR46 and a mixture dye of both of them were between 85 and 100%. For low and high inflow dye concentrations, best removals were generally recorded for spring and summer, respectively.

Development of a γ-alumina- nanoparticle-functionalized porous polymer monolith for the enrichment of Sudan dyes in red wine samples.

PubMed

Li, Wanjun; Zhou, Xiao; Ye, Juanjuan; Jia, Qiong

2013-10-01

Monolithic materials were synthesized in capillaries by in situ polymerization with N-isopropylacrylamide, glycidyl methacrylate, and ethylene dimethacrylate as the monomers, and methanol and PEG as the porogens. With γ-alumina nanoparticles attached to the surface of the porous monolithic column via epoxide groups, a novel polymer monolith microextraction (PMME) material was prepared with a good mechanical stability and a high extraction capacity. SEM and X-ray photoelectron spectroscopy were employed to characterize the modified monolithic column, demonstrating that γ-alumina nanoparticles were effectively functionalized onto the monolithic column. In addition, a new method was developed for the analysis of Sudan I-IV dyes using PMME coupled with HPLC. In order to obtain the optimum extraction efficiency, the PMME conditions including desorption solvent type, sample pH, sample volume, sample flow rate, and eluent flow rate were investigated. Under the optimum conditions, we obtained acceptable linearities, low LODs, and good intra- and interday RDSs. When applied to the determination of Sudan I-IV dyes in red wine samples, satisfactory recoveries were obtained in the range of 84.0-115.9%. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Movement and dispersion of soluble pollutants in the Northeast Cape Fear Estuary, North Carolina

USGS Publications Warehouse

Hubbard, E.F.; Stamper, William G.

1972-01-01

This report presents the results of a fluorescent-dye-tracing study to determine the concentrations of a pollutant that would be present in the Northeast Cape Fear Estuary at various rates of continuous waste injection and freshwater inflow. Rhodamine WT dye was introduced into the estuary at a constant rate over a 24.8-hour period (two tidal cycles) at a point 6.4 miles upstream from the mouth in Wilmington, N.C., and concentrations were monitored at several selected sections in the tide-affected part of the river for 17 days. The range between high and low tide in this reach of the estuary averages at-rut 3.5 feet, and there is usually strong flow in both directions. Results of the dye study indicate that if a pollutant were injected at a rate of 100 pounds per day under the conditions of relatively low inflow existing' at the time, concentrations would ultimately build up to 20 micrograms of dye per liter of water 1,000 feet downstream. The flushing time during the study is estimated to be 17 days. These results are extrapolated to include periods of lower or higher inflow. For example, at average intervals of 10 years, it is estimated that inflow is so low that 100 days are required for a pollutant to travel the 6.4 miles from the point of waste release to the mouth of the river. Under these conditions it is expected that 1,000 feet downstream from the point of waste discharge, daily maximum concentrations will average about 130 micrograms per liter for each 100 pounds of pollutant injected per day. Results of a continuous discharge measurement of flow made by current meter during a complete tidal cycle are presented as a part of this report. Data from this measurement and other evidence indicate that net upstream flow in the estuary is possible over a period of several days.

Formation and Fluorimetric Characterization of Micelles in a Micro-flow Through System with Static Micro Mixer

PubMed Central

Schuch, Michael; Gross, G. Alexander; Köhler, J. Michael

2007-01-01

The formation and behaviour of micelles of sodium dodecylsulfate in water by use of a static micro mixer were studied. Trisbipyridylruthenium(II) was applied as indicator dye, 9-methylanthracene was used for fluorescence quenching. All experiments were carried out by a micro fluid arrangement with three syringe pumps, a 2+1 two-step static micro mixer (IPHT Jena) and a on-line micro fluorimetry including a luminescence diode for excitation, a blue glass filter (BG 7, Linos), two edge filters (RG 630, Linos) and a photo counting module (MP 900, Perkin Elmer). It was possible to measure the fluorescence inside the PTFE tube (inner diameter 0.5 mm) directly. A linear dependence of fluorescence intensity from dye concentration was observed in absence of quencher and surfactant as expected. An aggregation number of about 62 was found in the flow rate range between 300 and 800 μL/min. The fluorescence intensity increases slightly, but significant with increasing flow rate, if no quencher is present. In the presence of quencher, the fluorescence intensity decreases with decreasing surfactant concentration and with enhanced flow rate. The strength of the flow rate effect on the fluorescence increases with decreasing surfactant concentration. The size of micelles was determined in micro channels by the micro fluorimetric method in analogy to the conventional system. The micelles extract the quencher from the solution and lower, this way, the quenching effect. The size of micelles was estimated and it could be shown, that the flow rate has only low effect on the aggregation number at the investigated flow rates. The effect of flow rate and surfactant concentration on the fluorescence in the presence of quencher was interpreted as a shift in the micelle concentration due to the shear forces. It is expected, that the fluorescence intensity is lowered, if more quencher molecules are molecular disperse distributed inside the solution. Obviously, the lowered fluorescence intensity at higher flow rates suggests a reduction of the micelle density causing an increase of quencher concentration outside the micelles. PMID:28903241

Effects of dissolved oxygen on dye removal by zero-valent iron.

PubMed

Wang, Kai-Sung; Lin, Chiou-Liang; Wei, Ming-Chi; Liang, Hsiu-Hao; Li, Heng-Ching; Chang, Chih-Hua; Fang, Yung-Tai; Chang, Shih-Hsien

2010-10-15

Effects of dissolved oxygen concentrations on dye removal by zero-valent iron (Fe(0)) were investigated. The Vibrio fischeri light inhibition test was employed to evaluate toxicity of decolorized solution. Three dyes, Acid Orange 7 (AO7, monoazo), Reactive Red 120 (RR120, diazo), and Acid Blue 9 (AB9, triphenylmethane), were selected as model dyes. The dye concentration and Fe(0) dose used were 100 mg L(-1) and 30 g L(-1), respectively. Under anoxic condition, the order for dye decolorization was AO7>RR120>AB9. An increase in the dissolved oxygen concentrations enhanced decolorization and chemical oxygen demand (COD) removal of the three dyes. An increase in gas flow rates also improved dye and COD removals by Fe(0). At dissolved oxygen of 6 mg L(-1), more than 99% of each dye was decolorized within 12 min and high COD removals were obtained (97% for AO7, 87% for RR120, and 93% for AB9). The toxicity of decolorized dye solutions was low (I(5)<40%). An increase in DO concentrations obviously reduced the toxicity. When DO above 2 mg L(-1) was applied, low iron ion concentration (13.6 mg L(-1)) was obtained in the decolorized AO7 solution. 2010 Elsevier B.V. All rights reserved.

Time of travel and dispersion in a selected reach of Roberts Creek, Clayton County, Iowa

USGS Publications Warehouse

Kolpin, D.W.; Kalkhoff, S.J.

1992-01-01

Time of travel was determined by dye tracing, using rhodamine WT as the tracer. One dyeinjection site and three sampling sites were used to measure time of travel. Two dye-tracing tests were conducted at discharges having flow-duration values of 48 and 80 percent. The discharges at the time of the two dye-tracing tests approximated medium- and low-flow conditions. The average stream velocity in the study area was 0.23 foot per second during medium-flow conditions, March 20 to 22,1990, and 0.07 foot per second during low-flow conditions, April 30 to May 12, 1990. The injected dye dispersed in a plume that lasted about 18 hours during medium flow and about 64 hours during low flow at the downstream site.

Tracer gauge: An automated dye dilution gauging system for ice‐affected streams

USGS Publications Warehouse

Clow, David W.; Fleming, Andrea C.

2008-01-01

In‐stream flow protection programs require accurate, real‐time streamflow data to aid in the protection of aquatic ecosystems during winter base flow periods. In cold regions, however, winter streamflow often can only be estimated because in‐channel ice causes variable backwater conditions and alters the stage‐discharge relation. In this study, an automated dye dilution gauging system, a tracer gauge, was developed for measuring discharge in ice‐affected streams. Rhodamine WT is injected into the stream at a constant rate, and downstream concentrations are measured with a submersible fluorometer. Data loggers control system operations, monitor key variables, and perform discharge calculations. Comparison of discharge from the tracer gauge and from a Cipoletti weir during periods of extensive ice cover indicated that the root‐mean‐square error of the tracer gauge was 0.029 m3 s−1, or 6.3% of average discharge for the study period. The tracer gauge system can provide much more accurate data than is currently available for streams that are strongly ice affected and, thus, could substantially improve management of in‐stream flow protection programs during winter in cold regions. Care must be taken, however, to test for the validity of key assumptions, including complete mixing and conservative behavior of dye, no changes in storage, and no gains or losses of water to or from the stream along the study reach. These assumptions may be tested by measuring flow‐weighted dye concentrations across the stream, performing dye mass balance analyses, and evaluating breakthrough curve behavior.

Dye tracing techniques used to determine ground-water flow in a carbonate aquifer system near Elizabethtown, Kentucky

USGS Publications Warehouse

Mull, D.S.; Smoot, J.L.; Liebermann, T.D.

1988-01-01

Because of the vulnerability of karst aquifers to contamination and the need for water managers to know recharge areas and groundwater flow characteristics for springs and wells used for public water supply, qualitative and quantitative dye tracing techniques were used during a groundwater investigation in the Elizabethtown area, Hardin County, in north-central Kentucky. The principal aquifer in the Elizabethtown area is thick, nearly horizontal beds of limestone, and thin beds of shale of Mississippi age. As much as 65% of all water pumped for the city water supply is obtained from two springs and two wells that obtain water from these rocks. Sinkholes were classified according to their ability to funnel runoff directly into the groundwater flow system, based primarily on the nature of the swallet draining the sinkhole. The presence of bedrock in the sinkhole nearly always ensured a well defined swallet leading to the subsurface. Qualitative and quantitative dye tracing techniques and equipment are discussed in detail. Qualitative dye tracing with fluorescein dye and passive dye detectors, consisting of activated coconut charcoal identified point to point connection between representative sinkholes, sinking streams, and karst windows and the city springs and wells. Qualitative tracing confirmed the presence of infiltrated surface water from a perennial stream, Valley Creek, in water from city wells and generally confirmed the direction of groundwater flow as shown by a water level contour map. Quantitative dye tracing with rhodamin WT, automatic samplers, discharge measurements, and fluorometric analyses were used to determine flow characteristics such as traveltime for arrival of the leading edge, peak concentration, trailing edge, and persistence of the dye cloud at the spring resurgence. Analyses of the dye recovery curves for quantitative dye traces completed between the same sinkholes and a city spring, and during different flow conditions showed that the arrival time of the leading edge of the dye cloud ranged from 5 to 24 hours and that the traveltime of the centroid of the dye cloud ranged from 6 to 31 hours when discharge was 4.6 and 0.53 cu ft/second, respectively. (Lantz-PTT)

Batch and column studies on biosorption of acid dyes on fresh water macro alga Azolla filiculoides.

PubMed

Padmesh, T V N; Vijayaraghavan, K; Sekaran, G; Velan, M

2005-10-17

The biosorption of Acid red 88 (AR88), Acid green 3 (AG3) and Acid orange 7 (AO7) by deactivated fresh water macro alga Azolla filiculoides was investigated in batch mode. Langmuir and Freundlich adsorption models were used for the mathematical description of the batch biosorption equilibrium data and model constants were evaluated. The adsorption capacity was pH dependent with a maximum value of 109.0 mg/g at pH 7 for AR88, 133.5 mg/g at pH 3 for AG3 and 109.6 mg/g at pH 3 for AO7, respectively, was obtained. The pseudo first and second order kinetic models were also applied to the experimental kinetic data and high correlation coefficients favor pseudo second order model for the present systems. The ability of A. filiculoides to biosorb AG3 in packed column was also investigated. The column experiments were conducted to study the effect of important design parameters such as initial dye concentration (50-100 mg/L), bed height (15-25 cm) and flow rate (5-15 mL/min) to the well-adsorbed dye. At optimum bed height (25 cm), flow rate (5 mL/min) and initial dye concentration (100 mg/L), A. filiculoides exhibited 28.1mg/g for AG3. The Bed Depth Service Time model and the Thomas model were used to analyze the experimental data and the model parameters were evaluated.

Dynamic Flow Velocity Mapping from Fluorescent Dye Transit Times in the Brain Surface Microcirculation of Anesthetized Rats and Mice.

PubMed

Hoshikawa, Ryo; Kawaguchi, Hiroshi; Takuwa, Hiroyuki; Ikoma, Yoko; Tomita, Yutaka; Unekawa, Miyuki; Suzuki, Norihiro; Kanno, Iwao; Masamoto, Kazuto

2016-08-01

This study aimed to develop a new method for mapping blood flow velocity based on the spatial evolution of fluorescent dye transit times captured with CLSFM in the cerebral microcirculation of anesthetized rodents. The animals were anesthetized with isoflurane, and a small amount of fluorescent dye was intravenously injected to label blood plasma. The CLSFM was conducted through a closed cranial window to capture propagation of the dye in the cortical vessels. The transit time of the dye over a certain distance in a single vessel was determined with automated image analyses, and average flow velocity was mapped in each vessel. The average flow velocity measured in the rat pial artery and vein was 4.4 ± 1.2 and 2.4 ± 0.5 mm/sec, respectively. A similar range of flow velocity to those of the rats was observed in the mice; 4.9 ± 1.4 and 2.0 ± 0.9 mm/sec, respectively, although the vessel diameter in the mice was about half of that in the rats. Flow velocity in the cerebral microcirculation can be mapped based on fluorescent dye transit time measurements with conventional CLSFM in experimental animals. © 2016 John Wiley & Sons Ltd.

In vitro performance of a perfusion and oxygenation optical sensor using a unique liver phantom

NASA Astrophysics Data System (ADS)

Akl, Tony J.; King, Travis J.; Long, Ruiqi; Ericson, M. N.; Wilson, Mark A.; McShane, Michael J.; Coté, Gerard L.

2012-03-01

Between the years 1999 and 2008, on average 2,052 people died per year on the waiting list for liver transplants. Monitoring perfusion and oxygenation in transplanted organs in the 7 to 14 days period post-transplant can enhance graft and patient survival rates, and resultantly increase the availability of organs. In this work, we present in vitro results using a unique liver phantom that support the ability of our sensor to detect perfusion changes in the portal vein at low levels (50 mL/min . 4.5% of normal level). Our sensor measures diffuse reflection from three wavelengths (735, 805 and 940 nm) around the hemoglobin isobestic point (805 nm) to determine perfusion and oxygenation separately. To assess the sensitivity of our sensor to flow changes in the low range, we used two peristaltic pumps to pump a dye solution mimicking the optical properties of oxygenated blood, at various rates, through a PDMS based phantom mimicking the optical properties of liver tissue. The collected pulsatile signal increased by 120% (2.2X) for every 100 mL/min flow rise for all three wavelengths in the range 50 to 500 mL/min. In addition, we used different dye mixtures to mimic oxygenation changes at constant perfusion/flow levels. The optical properties of the dye mixtures mimic oxygen saturations ranging between 0 and 100%. The sensor was shown to be sensitive to changes in oxygen saturations above 50%.

Microcolumn studies of dye adsorption onto manganese oxides modified diatomite.

PubMed

Al-Ghouti, M A; Khraisheh, M A M; Ahmad, M N; Allen, S J

2007-07-19

The method described here cannot fully replace the analysis of large columns by small test columns (microcolumns). The procedure, however, is suitable for speeding up the determination of adsorption parameters of dye onto the adsorbent and for speeding up the initial screening of a large adsorbent collection that can be tedious if a several adsorbents and adsorption conditions must be tested. The performance of methylene blue (MB), a basic dye, Cibacron reactive black (RB) and Cibacron reactive yellow (RY) was predicted in this way and the influence of initial dye concentration and other adsorption conditions on the adsorption behaviour were demonstrated. On the basis of the experimental results, it can be concluded that the adsorption of RY onto manganese oxides modified diatomite (MOMD) exhibited a characteristic "S" shape and can be simulated effectively by the Thomas model. It is shown that the adsorption capacity increased as the initial dye concentration increased. The increase in the dye uptake capacity with the increase of the adsorbent mass in the column was due to the increase in the surface area of adsorbent, which provided more binding sites for the adsorption. It is shown that the use of high flow rates reduced the time that RY in the solution is in contact with the MOMD, thus allowing less time for adsorption to occur, leading to an early breakthrough of RY. A rapid decrease in the column adsorption capacity with an increase in particle size with an average 56% reduction in capacity resulting from an increase in the particle size from 106-250 microm to 250-500 microm. The experimental data correlated well with calculated data using the Thomas equation and the bed depth-service time (BDST) equation. Therefore, it might be concluded that the Thomas equation and the BDST equations can produce accurate predication for variation of dye concentration, mass of the adsorbent, flow rate and particle size. In general, the values of adsorption isotherm capacity obtained in a batch system show the maximum values and are considerably higher than those obtained in a fixed-bed.

Fixed-bed adsorption of reactive azo dye onto granular activated carbon prepared from waste.

PubMed

Ahmad, A A; Hameed, B H

2010-03-15

In this work, the adsorption potential of bamboo waste based granular activated carbon (BGAC) to remove C.I. Reactive Black (RB5) from aqueous solution was investigated using fixed-bed adsorption column. The effects of inlet RB5 concentration (50-200mg/L), feed flow rate (10-30 mL/min) and activated carbon bed height (40-80 mm) on the breakthrough characteristics of the adsorption system were determined. The highest bed capacity of 39.02 mg/g was obtained using 100mg/L inlet dye concentration, 80 mm bed height and 10 mL/min flow rate. The adsorption data were fitted to three well-established fixed-bed adsorption models namely, Adam's-Bohart, Thomas and Yoon-Nelson models. The results fitted well to the Thomas and Yoon-Nelson models with coefficients of correlation R(2)>or=0.93 at different conditions. The BGAC was shown to be suitable adsorbent for adsorption of RB5 using fixed-bed adsorption column. (c) 2009 Elsevier B.V. All rights reserved.

Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor.

PubMed

Vallet, Ana; Besson, Michèle; Ovejero, Gabriel; García, Juan

2012-08-15

Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550°C. An increase in the reaction temperature (120-180°C), and a decrease in dye concentration (1000-3000 ppm) or liquid flow rate (0.1-0.7 mL min(-1)) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min(-1) and 180°C under 5 MPa air. Copyright © 2012 Elsevier B.V. All rights reserved.

Mineralization of reactive azo dyes present in simulated textile waste water using down flow microaerophilic fixed film bioreactor.

PubMed

Balapure, Kshama; Bhatt, Nikhil; Madamwar, Datta

2015-01-01

The present research emphasizes on degradation of azo dyes from simulated textile wastewater using down flow microaerophilic fixed film reactor. Degradation of simulated textile wastewater (COD 7200mg/L and dye concentration 300mg/L) was studied in a microaerophilic fixed film reactor using pumice stone as a support material under varying hydraulic retention time (HRT) and organic loading rate (OLR). The intense metabolic activity of the inoculated bacterial consortium in the reactor led to 97.5% COD reduction and 99.5% decolorization of simulated wastewater operated under OLR of 7.2kgCODm(3)/d and 24h of HRT. FTIR, (1)H NMR and GC-MS studies revealed the formation of lower molecular weight aliphatic compounds under 24h of HRT, leading to complete mineralization of simulated wastewater. The detection of oxido-reductive enzyme activities suggested the enzymatic reduction of azo bonds prior to mineralization. Toxicity studies indicated that microbial treatment favors detoxification of simulated wastewater. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Printing and dyeing wastewater treatment using combined process of anaerobic bioreactor and MBR].

PubMed

Zheng, Xiang; Liu, Jun-xin

2004-09-01

This paper describes a labor-scale experiment for printing and dyeing wastewater treatment of woolen mill using a combined process of an anaerobic reactor and a membrane bioreactor (MBR). The experimental results showed that when the concentration of COD, BOD5 and color in the influent were 128-321 mg/L, 36-95 mg/L and 40-70 dilution times (DT), the average concentrations of COD, BOD5, color and turbidity in the effluent were 36.9 mg/L, 3.7 mg/L, 21 DT and 0.24 NTU, respectively, and the corresponding removal rates were 80.3%, 95%, 59% and 99.3%, respectively. A new integrated membrane bioreactor by gravity drain of liquid level in the bioreactor was developed in this study. It not only lessens suction pump for effluent and controlling unit comparing to the traditional integrated membrane bioreactor, but also has the characters of high and continuous flux, concise configuration and simple operation and maintenance. According to the experimental results, the air flow rate through the membrane module is a significant factor to affect the flux rate and cake layer deposited on the membrane. With application of optimal air flow rate, it is effective to reduce membrane fouling and maintain high flux rate.

Determination of discharge during pulsating flow

USGS Publications Warehouse

Thompson, T.H.

1968-01-01

Pulsating flow in an open channel is a manifestation of unstable-flow conditions in which a series of translatory waves of perceptible magnitude develops and moves rapidly downstream. Pulsating flow is a matter of concern in the design and operation of steep-gradient channels. If it should occur at high stages in a channel designed for stable flow, the capacity of the channel may be inadequate at a discharge that is much smaller than that for which the channel was designed. If the overriding translatory wave carries an appreciable part of the total flow, conventional stream-gaging procedures cannot be used to determine the discharge; neither the conventional instrumentation nor conventional methodology is adequate. A method of determining the discharge during pulsating flow was tested in the Santa Anita Wash flood control channel in Arcadia, Calif., April 16, 1965. Observations of the dimensions and velocities of translatory waves were made during a period of controlled reservoir releases of about 100, 200, and 300 cfs (cubic feet per second). The method of computing discharge was based on (1) computation of the discharge in the overriding waves and (2) computation of the discharge in the shallow-depth, or overrun, part of the flow. Satisfactory results were obtained by this method. However, the procedure used-separating the flow into two components and then treating the shallow-depth component as though it were steady--has no theoretical basis. It is simply an expedient for use until laboratory investigation can provide a satisfactory analytical solution to the problem of computing discharge during pulsating flow. Sixteen months prior to the test in Santa Anita Wash, a robot camera had been designed .and programmed to obtain the data needed to compute discharge by the method described above. The photographic equipment had been installed in Haines Creek flood control channel in Los Angeles, Calif., but it had not been completely tested because of the infrequency of flow in that channel. Because the Santa Anita Wash tests afforded excellent data for analysis, further development of the photographic ,technique at Haines Creek was discontinued. Three methods for obtaining the data needed to compute discharge during pulsating flow are proposed. In two of the methods--the photographic method and the depth-recorder method--the dimensions and velocities of translatory waves are recorded, and discharge is then computed by the procedure developed in this report. The third method?the constant-rate-dye-dilution method--yields the discharge more directly. The discharge is computed from the dye-injection rate and the ratio of the concentration of dye in the injected solution to the concentration of dye in the water sampled at a site downstream. The three methods should be developed and tested in ,the Santa Anita Wash flood control channel under controlled conditions similar to those in the test of April 1965.

Measurement of blood flow through the retinal circulation of the cat during normoxia and hypoxemia using fluorescent microspheres.

PubMed

Ahmed, J; Pulfer, M K; Linsenmeier, R A

2001-09-01

The most successful method for measuring absolute blood flow rate through the retinal circulation has been the use of radioactive microspheres. The purpose of this study was to develop a microsphere method that did not have the drawbacks associated with radioactivity and to use this method to make measurements of retinal blood flow in the cat. Blood flow measurements were made by injecting 15-microm-diameter polystyrene microspheres into the left ventricle of anesthetized, artificially ventilated cats. These microspheres were labeled with one of three fluorescent dyes. Retinal blood flow measurements were made by determining the number of spheres that were embedded in the retina and comparing them to the number found in a reference sample. Spheres in the retina were counted by making retinal whole mounts and taking retinal images with a CCD camera mounted on an epifluorescence microscope equipped with filter sets appropriate for imaging the dyes used to label the spheres. Blood flow measurements made under normal conditions showed a mean retinal blood flow of 19.8 +/- 12.4 ml/min 100 g tissue (mean +/- SD; n = 15 cats). Since the retinal circulation perfuses only the inner half of the retina, the effective flow rate in that region is about twice this value. RBF increased during hypoxemia (P(a)O2 < 42 mm Hg) to 336% of the normoxic value on average. Analysis of sphere deposition patterns showed that the central retina had a higher blood flow than the peripheral retina, although this difference was significant only during hypoxemia. We conclude that even with a relatively small number of spheres deposited in the retina, the technique can reveal important properties of the retinal circulation. Copyright 2001 Academic Press.

Mineralization and Detoxification of the Carcinogenic Azo Dye Congo Red and Real Textile Effluent by a Polyurethane Foam Immobilized Microbial Consortium in an Upflow Column Bioreactor.

PubMed

Lade, Harshad; Govindwar, Sanjay; Paul, Diby

2015-06-16

A microbial consortium that is able to grow in wheat bran (WB) medium and decolorize the carcinogenic azo dye Congo red (CR) was developed. The microbial consortium was immobilized on polyurethane foam (PUF). Batch studies with the PUF-immobilized microbial consortium showed complete removal of CR dye (100 mg·L-1) within 12 h at pH 7.5 and temperature 30 ± 0.2 °C under microaerophilic conditions. Additionally, 92% American Dye Manufactureing Institute (ADMI) removal for real textile effluent (RTE, 50%) was also observed within 20 h under the same conditions. An upflow column reactor containing PUF-immobilized microbial consortium achieved 99% CR dye (100 mg·L-1) and 92% ADMI removal of RTE (50%) at 35 and 20 mL·h-l flow rates, respectively. Consequent reduction in TOC (83 and 79%), COD (85 and 83%) and BOD (79 and 78%) of CR dye and RTE were also observed, which suggested mineralization. The decolorization process was traced to be enzymatic as treated samples showed significant induction of oxidoreductive enzymes. The proposed biodegradation pathway of the dye revealed the formation of lower molecular weight compounds. Toxicity studies with a plant bioassay and acute tests indicated that the PUF-immobilized microbial consortium favors detoxification of the dye and textile effluents.

Mineralization and Detoxification of the Carcinogenic Azo Dye Congo Red and Real Textile Effluent by a Polyurethane Foam Immobilized Microbial Consortium in an Upflow Column Bioreactor

PubMed Central

Lade, Harshad; Govindwar, Sanjay; Paul, Diby

2015-01-01

A microbial consortium that is able to grow in wheat bran (WB) medium and decolorize the carcinogenic azo dye Congo red (CR) was developed. The microbial consortium was immobilized on polyurethane foam (PUF). Batch studies with the PUF-immobilized microbial consortium showed complete removal of CR dye (100 mg·L−1) within 12 h at pH 7.5 and temperature 30 ± 0.2 °C under microaerophilic conditions. Additionally, 92% American Dye Manufactureing Institute (ADMI) removal for real textile effluent (RTE, 50%) was also observed within 20 h under the same conditions. An upflow column reactor containing PUF-immobilized microbial consortium achieved 99% CR dye (100 mg·L−1) and 92% ADMI removal of RTE (50%) at 35 and 20 mL·h−l flow rates, respectively. Consequent reduction in TOC (83 and 79%), COD (85 and 83%) and BOD (79 and 78%) of CR dye and RTE were also observed, which suggested mineralization. The decolorization process was traced to be enzymatic as treated samples showed significant induction of oxidoreductive enzymes. The proposed biodegradation pathway of the dye revealed the formation of lower molecular weight compounds. Toxicity studies with a plant bioassay and acute tests indicated that the PUF-immobilized microbial consortium favors detoxification of the dye and textile effluents. PMID:26086710

Preparation and flow cytometry of uniform silica-fluorescent dye microspheres.

PubMed

Bele, Marjan; Siiman, Olavi; Matijević, Egon

2002-10-15

Uniform fluorescent silica-dye microspheres have been prepared by coating preformed monodispersed silica particles with silica layers containing rhodamine 6G or acridine orange. The resulting dispersions exhibit intense fluorescent emission between 500 and 600 nm, over a broad excitation wavelength range of 460 to 550 nm, even with exceedingly small amounts of dyes incorporated into the silica particles (10-30 ppm, expressed as weight of dye relative to weight of dry particles). The fluorescent particles can be prepared in micrometer diameters suitable for analyses using flow cytometry with 488-nm laser excitation.

Synthesis and photocatalytic property of Zinc Oxide (ZnO) fine particle using flame spray pyrolysis method

NASA Astrophysics Data System (ADS)

Widiyandari, Hendri; Ayu Ketut Umiati, Ngurah; Dwi Herdianti, Rizki

2018-05-01

Advance oxidation process (AOP) using photocatalysis constitute a promising technology for the treatment of wastewaters containing non-easily removable organic compound. Zinc oxide (ZnO) is one of efficient photocatalyst materials. This research reported synthesis of ZnO fine particle from zinc nitrate hexahydrate using Flame Spray Pyrolysis (FSP) method. In this method, oxygen (O2) gas were used as oxidizer and LPG (liquid petroleum gas) were used as fuel. The effect of O2 gas flow rate during ZnO particle fabrication to the microstructure, optical and photocatalytic properties were systematically discussed. The photocatalytic activity of ZnO was tested for the degradation of amaranth dye with initial concentration of 10 ppm under irradiation of solar simulator. The rate of decrease in amaranth concentration was measured using UV-Visible spectrophotometer. The ZnO synthesized using FSP has a hexagonal crystalline structure. Scanning electron microscope images showed that ZnO has a spherical formed which was the mixture of solid and hollow particles. The optimum condition for amaranth degradation was shown by ZnO produced at a flow rate of 1.5 L/min which able to degrade amaranth dye up to 95,3 % at 75 minutes irradiation.

The use of fluorescent indoline dyes for side population analysis.

PubMed

Kohara, Hiroshi; Watanabe, Kohei; Shintou, Taichi; Nomoto, Tsuyoshi; Okano, Mie; Shirai, Tomoaki; Miyazaki, Takeshi; Tabata, Yasuhiko

2013-01-01

Dye efflux assay evaluated by flow cytometry is useful for stem cell studies. The side population (SP) cells, characterized by the capacity to efflux Hoechst 33342 dye, have been shown to be enriched for hematopoietic stem cells (HSCs) in bone marrow. In addition, SP cells are isolated from various tissues and cell lines, and are also potential candidates for cancer stem cells. However, ultra violet (UV) light, which is not common for every flow cytometer, is required to excite Hoechst 33342. Here we showed that a fluorescent indoline dye ZMB793 can be excited by 488-nm laser, equipped in almost all the modern flow cytometers, and ZMB793-excluding cells showed SP phenotype. HSCs were exclusively enriched in the ZMB793-excluding cells, while ZMB793 was localized in cytosol of bone marrow lineage cells. The efflux of ZMB793 dye was mediated by ATP binding cassette (ABC) transporter Abcg2. Moreover, staining properties were affected by the side-chain structure of the dyes. These data indicate that the fluorescent dye ZMB793 could be used for the SP cell analysis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Numerical model of a tracer test on the Santa Clara River, Ventura County, California

USGS Publications Warehouse

Nishikawa, Tracy; Paybins, Katherine S.; Izbicki, John A.; Reichard, Eric G.

1999-01-01

To better understand the flow processes, solute-transport processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 45-km reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the lower Piru Creek and the middle Santa Clara River. The tracer-test data were used to calibrate a one-dimensional flow model (DAFLOW) and a solute-transport model (BLTM). The dye-arrival times at each sample location were simulated by calibrating the velocity parameters in DAFLOW. The simulations of dye transport indicated that (1) ground-water recharge explains the loss of mass in the ephemeral middle subreaches, and (2) groundwater recharge does not explain the loss of mass in the perennial uppermost and lowermost subreaches. The observed tracer curves in the perennial subreaches were indicative of sorptive dye losses, transient storage, and (or) photodecay - these phenomena were simulated using a linear decay term. However, analysis of the linear decay terms indicated that photodecay was not a dominant source of dye loss.To better understand the flow processes, solute-transport processes, and ground-water/surface-water interactions on the Santa Clara River in Ventura County, California, a 24-hour fluorescent-dye tracer study was performed under steady-state flow conditions on a 45-km reach of the river. The study reach includes perennial (uppermost and lowermost) subreaches and ephemeral subreaches of the lower Piru Creek and the middle Santa Clara River. The tracer-test data were used to calibrate a one-dimension-al flow model (DAFLOW) and a solute-transport model (BLTM). The dye-arrival times at each sample location were simulated by calibrating the velocity parameters in DAFLOW. The simulations of dye transport indicated that (1) ground-water recharge explains the loss of mass in the ephemeral middle subreaches, and (2) ground-water recharge does not explain the loss of mass in the perennial uppermost and lowermost subreaches. The observed tracer curves in the perennial subreaches were indicative of sorptive dye losses, transient storage, and (or) photodecay - these phenomena were simulated using a linear decay term. However, analysis of the linear decay terms indicated that photodecay was not a dominant source of dye loss.

Development of an activated carbon-packed microbial bioelectrochemical system for azo dye degradation.

PubMed

Cardenas-Robles, Arely; Martinez, Eduardo; Rendon-Alcantar, Idelfonso; Frontana, Carlos; Gonzalez-Gutierrez, Linda

2013-01-01

A microbial bioelectrochemical reactor (BER) was employed for the degradation of azo dyes without the use of an external electron donor, using activated carbon (GAC) as a redox mediator. Contribution of pH values, open circuit potential (OCP), dye concentration and applied current were individually studied. A batch system and an upflow fixed bed bioreactor were built for analyzing the effect of the applied current on biodegradation of the azo dye Reactive Red 272. The presence of GAC (20% w/v) regulated both pH and OCP values in solution and led to a removal efficiency of 98%. Cyclic voltammetry results indicate a dependence of the electron transfer mechanism with the concentration of the azo compound. With these results, a continuous flow reactor operating with J=0.045 mA cm(-2), led to removal rates of 95% (± 3.5%) in a half-residence time of 1 hour. Copyright © 2012 Elsevier Ltd. All rights reserved.

Passive Microfluidic device for Sub Millisecond Mixing

PubMed Central

McMahon, Jay; Mohamed, Hisham; Barnard, David; Shaikh, Tanvir R.; Mannella, Carmen A.; Wagenknecht, Terence; Lu, Toh-Ming

2009-01-01

We report the investigation of a novel microfluidic mixing device to achieve submillisecond mixing. The micromixer combines two fluid streams of several microliters per second into a mixing compartment integrated with two T- type premixers and 4 butterfly-shaped in-channel mixing elements. We have employed three dimensional fluidic simulations to evaluate the mixing efficiency, and have constructed physical devices utilizing conventional microfabrication techniques. The simulation indicated thorough mixing at flow rate as low as 6 µL/s. The corresponding mean residence time is 0.44 ms for 90% of the particles simulated, or 0.49 ms for 95% of the particles simulated, respectively. The mixing efficiency of the physical device was also evaluated using fluorescein dye solutions and FluoSphere-red nanoparticles suspensions. The constructed micromixers achieved thorough mixing at the same flow rate of 6 µL/s, with the mixing indices of 96% ± 1%, and 98% ± 1% for the dye and the nanoparticle, respectively. The experimental results are consistent with the simulation data. The device demonstrated promising capabilities for time resolved studies for macromolecular dynamics of biological macromolecules. PMID:20161619

Assessing Urinary Tract Junction Obstruction Defects by Methylene Blue Dye Injection.

PubMed

Yun, Kangsun

2017-10-12

Urinary tract junction obstruction defects are congenital anomalies inducing hydronephrosis and hydroureter. Murine urinary tract junction obstruction defects can be assessed by tracking methylene blue dye flow within the urinary system. Methylene blue dye is injected into the renal pelvis of perinatal embryonic kidneys and dye flow is monitored from the renal pelvis of the kidney through the ureter and into the bladder lumen after applying hydrostatic pressure. Dye accumulation will be evident in the bladder lumen of the normal perinatal urinary tract, but will be constrained between the renal pelvis and the end point of an abnormal ureter, if urinary tract obstructions occur. This method facilitates the confirmation of urinary tract junction obstructions and visualization of hydronephrosis and hydroureter. This manuscript describes a protocol for methylene blue dye injection into the renal pelvis to confirm urinary tract junction obstructions.

Cardiovascular system simulation in biomedical engineering education.

NASA Technical Reports Server (NTRS)

Rideout, V. C.

1972-01-01

Use of complex cardiovascular system models, in conjunction with a large hybrid computer, in biomedical engineering courses. A cardiovascular blood pressure-flow model, driving a compartment model for the study of dye transport, was set up on the computer for use as a laboratory exercise by students who did not have the computer experience or skill to be able to easily set up such a simulation involving some 27 differential equations running at 'real time' rate. The students were given detailed instructions regarding the model, and were then able to study effects such as those due to septal and valve defects upon the pressure, flow, and dye dilution curves. The success of this experiment in the use of involved models in engineering courses was such that it seems that this type of laboratory exercise might be considered for use in physiology courses as an adjunct to animal experiments.

Upscaling mixing in porous media from an experimental quantification of pore scale Lagrangian deformation statistics

NASA Astrophysics Data System (ADS)

Turuban, R.; Jimenez-Martinez, J.; De Anna, P.; Tabuteau, H.; Meheust, Y.; Le Borgne, T.

2014-12-01

As dissolved chemical elements are transported in the subsurface, their mixing with other compounds and potential reactivity depends on the creation of local scale chemical gradients, which ultimately drive diffusive mass transfer and reaction. The distribution of concentration gradients is in turn shaped by the spatial gradients of flow velocity arising from the random distribution of solid grains. We present an experimental investigation of the relationship between the microscale flow stretching properties and the effective large scale mixing dynamics in porous media. We use a flow cell that models a horizontal quasi two-dimensional (2D) porous medium, the grains of which are cylinders randomly positioned between two glass plates [de Anna et al. 2013]. In this setup, we perform both non diffusive and diffusive transport tests, by injecting respectively microsphere solid tracers and a fluorescent dye. While the dye front propagates through the medium, it undergoes in time a kinematic stretching that is controlled by the flow heterogeneity, as it encounters stagnation zones and high velocity channels between the grains. The spatial distribution of the dye can then be described as a set of stretched lamellae whose rate of diffusive smoothing is locally enhanced by kinematic stretching [Le Borgne et al., 2013]. We show that this representation allows predicting the temporal evolution of the mixing rate and the probability distribution of concentration gradients for a range of Peclet numbers. This upscaling framework hence provides a quantification of the dynamics of effective mixing from the microscale Lagrangian velocity statistics. References:[1] P. de Anna, J. Jimenez-Martinez, H. Tabuteau, R. Turuban, T. Le Borgne, M. Derrien,and Yves Méheust, Mixing and reaction kinetics in porous media : an experimental pore scale quantification, Environ. Sci. Technol. 48, 508-516, 2014. [2] Le Borgne, T., M. Dentz, E. Villermaux, Stretching, coalescence and mixing in porous media, Phys. Rev. Lett., 110, 204501 (2013)

Mixing-induced fluid destratification and ullage condensation

NASA Technical Reports Server (NTRS)

Meserole, Jere S.; Jones, Ogden S.; Fortini, Anthony F.

1987-01-01

In many applications, on-orbit storage and transfer of cryogens will require forced mixing to control tank pressure without direct venting to space. During a no-vent transfer or during operation of a thermodynamic vent system in a cryogen storage tank, pressure control is achieved by circulating cool liquid to the liquid-vapor interface to condense some of the ullage vapor. To measure the pressure and temperature response rates in mixing-induced condensation, an experiment has been developed using Freon 11 to simulate the two-phase behavior of a cryogen. A thin layer at the liquid surface is heated to raise the tank pressure, and then a jet mixer is turned on to circulate the liquid, cool the surface, and reduce the pressure. Many nozzle configurations and flow rates are used. Tank pressure and the temperature profiles in the ullage and the liquid are measured. Initial data from this ground test are shown correlated with normal-gravity and drop-tower dye-mixing data. Pressure collapse times are comparable to the dye-mixing times, whereas the times needed for complete thermal mixing are much longer than the dye-mixing times.

Positively charged microporous ceramic membrane for the removal of Titan Yellow through electrostatic adsorption.

PubMed

Cheng, Xiuting; Li, Na; Zhu, Mengfu; Zhang, Lili; Deng, Yu; Deng, Cheng

2016-06-01

To develop a depth filter based on the electrostatic adsorption principle, positively charged microporous ceramic membrane was prepared from a diatomaceous earth ceramic membrane. The internal surface of the highly porous ceramic membrane was coated with uniformly distributed electropositive nano-Y2O3 coating. The dye removal performance was evaluated through pressurized filtration tests using Titan Yellow aqueous solution. It showed that positively charged microporous ceramic membrane exhibited a flow rate of 421L/(m(2)·hr) under the trans-membrane pressure of 0.03bar. Moreover it could effectively remove Titan Yellow with feed concentration of 10mg/L between pH3 to 8. The removal rate increased with the enhancement of the surface charge properties with a maximum rejection of 99.6%. This study provides a new and feasible method of removing organic dyes in wastewater. It is convinced that there will be a broad market for the application of charged ceramic membrane in the field of dye removal or recovery from industry wastewater. Copyright © 2016. Published by Elsevier B.V.

Using dye tracing to establish groundwater flow paths in a limestone marble aquifer, University of California, Santa Cruz, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, J.; Bertschinger, V.; Aley, T.

1993-04-01

Areas underlain by karst aquifers are characterized by soluble rock with sinkholes, caves, and a complex underground drainage network. Groundwater issues such as flow direction, well pumping impacts, spring recharge areas, and potential contamination transport routes are greatly complicated by the unique structure of karst aquifers. Standard aquifer analysis techniques cannot be applied unless the structure of the karst aquifer is understood. Water soluble fluorescent dyes are a powerful tool for mapping the irregular subsurface connections and flow paths in karst aquifers. Mapping the subsurface connections allows reasonable estimates of the hydrologic behavior of the aquifer. Two different fluorescent dyesmore » were injected at two points in a limestone karst aquifer system beneath the University of California, Santa Cruz campus. Flow paths in the marble were thought to be closely tied to easily recognized geomorphic alignments of sinkholes associated with fault and fracture zones. The dye tests revealed unexpected and highly complex interconnections. These complex flow paths only partially corresponded to previous surface mapping and aerial photo analysis of fracture systems. Several interfingering but hydrologically unconnected flow paths evidently exist within the cavernous aquifer. For example, dye did not appear at some discharge springs close to the dye injection points, but did appear at more distant springs. This study shows how a dye tracing study in a small, well-defined limestone body can shed light on a variety of environmental and hydrological issues, including potential well pumping impact areas, wellhead protection and recharge areas, parking lot runoff injection to aquifers, and drainage routes from hazardous materials storage areas.« less

Monitoring Cell Proliferation by Dye Dilution: Considerations for Probe Selection

PubMed Central

Tario, Joseph D.; Conway, Alexis N.; Muirhead, Katharine A.; Wallace, Paul K.

2018-01-01

In the third edition of this series, we described protocols for labeling cell populations with tracking dyes, and addressed issues to be considered when combining two different tracking dyes with other phenotypic and viability probes for the assessment of cytotoxic effector activity and regulatory T cell functions. We summarized key characteristics of and differences between general protein and membrane labeling dyes, discussed determination of optimal staining concentrations, and provided detailed labeling protocols for both dye types. Examples of the advantages of two color cell tracking were provided in the form of protocols for: (a) independent enumeration of viable effector and target cells in a direct cytotoxicity assay; and (b) an in vitro suppression assay for simultaneous proliferation monitoring of effector and regulatory T cells. The number of commercially available fluorescent cell tracking dyes has expanded significantly since the last edition, with new suppliers and/or new spectral properties being added at least annually. In this fourth edition, we describe evaluations to be performed by the supplier and/or user when characterizing a new cell tracking dye and by the user when selecting one for use in multicolor proliferation monitoring. These include methods for: Assessment of the dye’s spectral profile on the laboratory’s flow cytometer(s) to optimize compatibility with other employed fluorochromes and minimize compensation problems;Evaluating the effect of labeling on cell growth rate;Testing the fidelity with which dye dilution reports cell division;Determining the maximum number of generations to be included when using dye dilution profiles to estimate fold population expansion or frequency of responder cells; andVerifying that relevant cell functions (e.g., effector activity) remain unaltered by tracking dye labeling. PMID:29071683

New method for measuring water seepage through salmon spawning gravel.

Treesearch

Richard D. Orchard

1988-01-01

A new method, with heat as a tracer, was developed for measuring rate and direction of intragravel waterflow through salmon spawning gravel. A commercial flowmeter was calibrated in the laboratory under controlled environmental conditions. Flow measurements comparing the flowmeter with a dye-tracer method were made in an artificial stream channel at Young Bay and in...

Co and Fe-catalysts supported on sepiolite: effects of preparation conditions on their catalytic behaviors in high temperature gas flow treatment of dye.

PubMed

Lin, Xiangfeng; Fang, Jian; Chen, Menglin; Huang, Zhi; Su, Chengyuan

2016-08-01

An efficient adsorbent/catalyst Co and Fe-catalysts loaded on sepiolite (Co-Fe/sepiolite) was successfully prepared for high temperature gas flow catalytic reaction by a simple impregnation method. The impact of preparation conditions (such as pH value of impregnation solution, impregnation time, calcination temperature, and time) on catalytic activity was studied. We found that the catalytic activity of Co-Fe/sepiolite was strongly influenced by all the investigated parameters. The regeneration efficiency (RE) was used to evaluate the catalytic activity. The RE is more noticeable at pH 5.0 of impregnation solution, impregnation time 18 h, calcination temperature 650 °C, and calcination time 3 h. This Co-Fe/sepiolite has great adsorption capacity in absorbing dye. It is used for an adsorbent to adsorb dye from wastewater solution under dynamic adsorption and saturated with dye, then regenerated with high temperature gas flow for adsorption/oxidation cycles. The Co-Fe/sepiolite acts as a catalyst to degrade the dye during regeneration under high temperature gas flow. Hence, the Co-Fe/sepiolite is not only an adsorbent but also a catalyst. The Co-Fe/sepiolite is more stable than sepiolite when applied in the treatment of plant's wastewater. The Co-Fe/sepiolite can be reused in adsorption-regeneration cycle. The results indicate the usability of the proposed combined process, dye adsorption on Co-Fe/sepiolite followed by the catalytic oxidation in high temperature gas flow.

Preferential flow and pesticide transport in a clay-rich till: Field, laboratory, and modeling analysis

NASA Astrophysics Data System (ADS)

JøRgensen, Peter R.; Hoffmann, Martin; Kistrup, Jens P.; Bryde, Claus; Bossi, Rossana; Villholth, Karen G.

2002-11-01

This study investigates vertical flow and pesticide transport along fractures in water saturated unoxidized clayey till. From two experimental fields, each 40 m2, 96% and 98%, respectively, of total vertical flow was conducted along fractures in the till, while the remaining 2-4% of flow occurred in the clay matrix at very slow flow rate. An applied dye tracer was observed only along 10-26% of the total fracture length measured on the horizontal surface of the experimental fields. In vertical sections the dyed fracture portions constituted root channels, which penetrated the till vertically along the fractures into the local aquifer at 5 m depth. No dye tracer was observed in the fractures without root channels or in the unfractured clay matrix, suggesting that root growth along the fracture surfaces was the principal agent of fracture aperture enhancement. Using hydraulic fracture aperture values determined from large undisturbed column (LUC) collected from one of the experimental fields, it was estimated that 94% of flow in the fractures was conducted along the fracture root channels, while only 6% of flow was conducted along the fracture sections without root channels. For natural vertical hydraulic gradients (0.8-2.3 at the site), flow rates of 0.8-2 km/d were determined for a fracture root channel, while fracture sections without root channels revealed flow rates of 9-22 m/d. Corresponding flow rates in the unfractured matrix were 7-19 mm/yr. For infiltrated bromide (nonreactive tracer) and mobile pesticides mecoprop (MCPP) and metsulfuron, very rapid migration (0.28-0.5 m/d) and high relative breakthrough concentrations (30-60%) into the aquifer were observed to occur along the fracture root channels using a constant hydraulic gradient of 1. Only traces were measured from infiltration of the strongly sorbed pesticide prochloraz. The concentrations of the bromide and pesticides in the monitoring wells were modeled with a discrete fracture matrix diffusion (DFDM) model coupled with a single porosity model (SP) for the till and aquifer, respectively. Using effective fracture spacings and mean fracture apertures for the fracture channel sections as modeling input parameters for the till, the concentrations observed in the wells of the aquifer could be reasonably approximated.

An Assessment of Aquifer/Well Flow Dynamics: Identification of Parameters Key to Passive Sampling and Application of Downhole Sensor Technologies

DTIC Science & Technology

2014-12-01

Simulated Solute Transport in a Numerical Replication of Britt’s 2005 Experiment Figure 44 In-Well Flow Inhibitor Figure 45 Results of a Preliminary Dye ...Tracer Experiment Conducted at INL Figure 46 Results Horizontally-Oriented Dye Tracer Experiment Conducted at INL ER-1704 Final Report 2014 vii...possible sources of well convection and mixing. Specifically, the modeling explored: • 2D and 3D physical tank models. Dye tracer testing was conducted

Flow through the nasal cavity of the spiny dogfish, Squalus acanthias

NASA Astrophysics Data System (ADS)

Timm-Davis, L. L.; Fish, F. E.

2015-12-01

The nasal cavity of spiny dogfish is a blind capsule with no internal connection to the oral cavity. Water is envisioned to flow through the cavity in a smooth, continuous flow pattern; however, this assumption is based on previous descriptions of the morphology of the olfactory cavity. No experimentation on the flow through the internal nasal cavity has been reported. Morphology of the head of the spiny dogfish ( Squalus acanthias) does not suggest a close external connection between the oral and nasal systems. However, dye visualization showed that there was flow through the nasal apparatus and from the excurrent nostril to the mouth when respiratory flows were simulated. The hydrodynamic flow through the nasal cavity was observed from flow tank experiments. The dorsum of the nasal cavity of shark heads from dead animals was exposed by dissection and a glass plate was glued over of the exposed cavity. When the head was placed in a flow, dye was observed to be drawn passively into the cavity showing a complex, three-dimensional hydrodynamic flow. Dye entered the incurrent nostril, flowed through the nasal lamellae, crossed over and under the nasal valve, and circulated around the nasal valve before exiting the excurrent nostril. When the nasal valve was removed, the dye became stagnant and back flowed out through the incurrent nostril. The single nasal valve has a hydrodynamic function that organizes a coherent flow of water through the cavity without disruption. The results suggest that the morphology of the nasal apparatus in concert with respiratory flow and ambient flows from active swimming can be used to draw water through the olfactory cavity of the shark.

Microencapsulated Fluorescent Dye Penetrant.

DTIC Science & Technology

1979-07-01

Microencapsulated fluorescent dye pentrant materials were evaluated for feasibility as a technique to detect cracks on metal surfaces when applied as...a free flowing dry powder. Various flourescent dye solutions in addition to a commercial penetrant (Zyglo ZL-30) were microencapsulated and tested on

Ni/MgAlO regeneration for catalytic wet air oxidation of an azo-dye in trickle-bed reaction.

PubMed

Vallet, Ana; Ovejero, Gabriel; Rodríguez, Araceli; Peres, José A; García, Juan

2013-01-15

Active nickel catalysts (7 wt%) supported over Mg-Al mixed oxides have been recently developed and it has also been demonstrated that they are also highly selective in Catalytic Wet air Oxidation (CWAO) of dyes. CWAO of Chromotrope 2R (C2R) has been studied using a trickle bed reactor employing temperatures from 100 to 180 °C, liquid flow rates from 0.1 to 0.7 mL min(-1) and initial dye concentration from 10 to 50 ppm. Total pressure and air flow were 25 bar and 300 mL min(-1), respectively. The catalyst showed a very stable activity up to 24 h on stream with an average TOC conversion of 82% at 150 °C and T(r)=0.098 g(Ni) min mL(-1). After the reaction, a 1.1 wt% C of carbonaceous deposit is formed onto the catalyst and a diminution of 30% of the surface area with respect of the fresh catalyst was observed. An increase in the space time gave higher TOC conversions up to T(r)=0.098 g(Ni) min mL(-1), attaining values of 80% at 180 °C. The performance of TOC and dye removal does not decrease after two regeneration cycles. In total, a 57 h effective reaction has been carried out with no loss of catalytic activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Hydrodynamic and kinetic study of a hybrid detoxification process with zero liquid discharge system in an industrial wastewater treatment.

PubMed

Abid, Mohammad Fadhil; Abdulrahman, Amir Aziz; Hamza, Noor Hussein

2014-01-01

This work focused on the degradation of toxic organic compounds such as methyl violet dye (MV) in water, using a combined photocatalysis/low pressure reverse osmosis (LPRO) system. The performance of the hybrid system was investigated in terms of the degradation efficiency of MV, COD and membrane separation of TiO2. The aim of the present study was to design a novel solar reactor and analyze its performance for removal of MV from water with titanium dioxide as the photocatalyst. Various operating parameters were studied to investigate the behavior of the designed reactor like initial dye concentration (C = 10-50 mg/L), loading of catalyst (CTiO2 = 200-800 mg/L), suspension flow rate (QL = 0.3-1.5 L/min), pH of suspension (5-10), and H2O2 concentration (CH2O2 = 200-1000 mg/L). The operating parameters were optimized to give higher efficiency to the reactor performance. Optimum parameters of the photocatalysis process were loading of catalyst (400 mg/L), suspension flow rate (0.5 L/min), H2O2 concentration (400 mg/L), and pH = 5. The designed reactor when operating at optimum conditions offered a degradation of MV up to 0.9527 within one hours of operation time, while a conversion of 0.9995 was obtained in three hours. The effluent from the photocatalytic reactor was fed to a LPRO separation system which produced permeate of turbidity value of 0.09 NTU which is closed to that of drinking water (i.e., 0.08 NTU). The product water was analyzed using UV-spectrophotometer and FTIR. The analysis results confirmed that the water from the Hybrid-System could be safely recycled and reuse. It was found that the kinetics of dye degradation was first order with respect to dye concentration and could be well described by Langmuir-Hinshelwood model. A power-law based empirical correlation was developed for the photocatalysis system, related the dye degradation (R) with studied operating conditions.

Kinetics of leather dyeing pretreated with enzymes: role of acid protease.

PubMed

Kanth, Swarna Vinodh; Venba, Rajangam; Jayakumar, Gladstone Christopher; Chandrababu, Narasimhan Kannan

2009-04-01

In the present investigation, kinetics of dyeing involving pretreatment with acid protease has been presented. Application of acid protease in dyeing process resulted in increased absorption and diffusion of dye into the leather matrix. Enzyme treatment at 1% concentration, 60 min duration and 50 degrees C resulted in maximum of 98% dye exhaustion and increased absorption rate constants. The final exhaustion (C(infinity)) for the best fit of CI Acid Black 194 dye has been 98.5% with K and r2 values from the modified Cegarra-Puente isotherm as 0.1033 and 0.0631. CI Acid Black 194 being a 2:1 metal complex acid dye exhibited higher absorption rate than the acid dye CI Acid Black 210. A reduction in 50% activation energy calculated from Arrhenius equation has been observed in enzyme assisted dyeing process of both the dyes that substantiates enhanced dye absorption. The absorption rate constant calculated with modified Cegarra-Puente equation confirm higher rate constants and faster kinetics for enzyme assisted dyeing process. Enzyme treated leather exhibited richness of color and shade when compared with control. The present study substantiates the essential role of enzyme pretreatment as an eco-friendly leather dyeing process.

Rapid multi-wavelength optical assessment of circulating blood volume without a priori data

NASA Astrophysics Data System (ADS)

Loginova, Ekaterina V.; Zhidkova, Tatyana V.; Proskurnin, Mikhail A.; Zharov, Vladimir P.

2016-03-01

The measurement of circulating blood volume (CBV) is crucial in various medical conditions including surgery, iatrogenic problems, rapid fluid administration, transfusion of red blood cells, or trauma with extensive blood loss including battlefield injuries and other emergencies. Currently, available commercial techniques are invasive and time-consuming for trauma situations. Recently, we have proposed high-speed multi-wavelength photoacoustic/photothermal (PA/PT) flow cytometry for in vivo CBV assessment with multiple dyes as PA contrast agents (labels). As the first step, we have characterized the capability of this technique to monitor the clearance of three dyes (indocyanine green, methylene blue, and trypan blue) in an animal model. However, there are strong demands on improvements in PA/PT flow cytometry. As additional verification of our proof-of-concept of this technique, we performed optical photometric CBV measurements in vitro. Three label dyes—methylene blue, crystal violet and, partially, brilliant green—were selected for simultaneous photometric determination of the components of their two-dye mixtures in the circulating blood in vitro without any extra data (like hemoglobin absorption) known a priori. The tests of single dyes and their mixtures in a flow system simulating a blood transfusion system showed a negligible difference between the sensitivities of the determination of these dyes under batch and flow conditions. For individual dyes, the limits of detection of 3×10-6 M‒3×10-6 M in blood were achieved, which provided their continuous determination at a level of 10-5 M for the CBV assessment without a priori data on the matrix. The CBV assessment with errors no higher than 4% were obtained, and the possibility to apply the developed procedure for optical photometric (flow cytometry) with laser sources was shown.

Determination of the mass transfer limiting step of dye adsorption onto commercial adsorbent by using mathematical models.

PubMed

Marin, Pricila; Borba, Carlos Eduardo; Módenes, Aparecido Nivaldo; Espinoza-Quiñones, Fernando R; de Oliveira, Silvia Priscila Dias; Kroumov, Alexander Dimitrov

2014-01-01

Reactive blue 5G dye removal in a fixed-bed column packed with Dowex Optipore SD-2 adsorbent was modelled. Three mathematical models were tested in order to determine the limiting step of the mass transfer of the dye adsorption process onto the adsorbent. The mass transfer resistance was considered to be a criterion for the determination of the difference between models. The models contained information about the external, internal, or surface adsorption limiting step. In the model development procedure, two hypotheses were applied to describe the internal mass transfer resistance. First, the mass transfer coefficient constant was considered. Second, the mass transfer coefficient was considered as a function of the dye concentration in the adsorbent. The experimental breakthrough curves were obtained for different particle diameters of the adsorbent, flow rates, and feed dye concentrations in order to evaluate the predictive power of the models. The values of the mass transfer parameters of the mathematical models were estimated by using the downhill simplex optimization method. The results showed that the model that considered internal resistance with a variable mass transfer coefficient was more flexible than the other ones and this model described the dynamics of the adsorption process of the dye in the fixed-bed column better. Hence, this model can be used for optimization and column design purposes for the investigated systems and similar ones.

Microwave atmospheric pressure plasma jets for wastewater treatment: Degradation of methylene blue as a model dye.

PubMed

García, María C; Mora, Manuel; Esquivel, Dolores; Foster, John E; Rodero, Antonio; Jiménez-Sanchidrián, César; Romero-Salguero, Francisco J

2017-08-01

The degradation of methylene blue in aqueous solution as a model dye using a non thermal microwave (2.45 GHz) plasma jet at atmospheric pressure has been investigated. Argon has been used as feed gas and aqueous solutions with different concentrations of the dye were treated using the effluent from plasma jet in a remote exposure. The removal efficiency increased as the dye concentration decreased from 250 to 5 ppm. Methylene blue degrades after different treatment times, depending on the experimental plasma conditions. Thus, kinetic constants up to 0.177 min -1 were obtained. The higher the Ar flow, the faster the degradation rate. Optical emission spectroscopy (OES) was used to gather information about the species present in the gas phase, specifically excited argon atoms. Argon excited species and hydrogen peroxide play an important role in the degradation of the dye. In fact, the conversion of methylene blue was directly related to the density of argon excited species in the gas phase and the concentration of hydrogen peroxide in the aqueous liquid phase. Values of energy yield at 50% dye conversion of 0.296 g/kWh were achieved. Also, the use of two plasma applicators in parallel has been proven to improve energy efficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Interfacial charge separation and photovoltaic efficiency in Fe(ii)-carbene sensitized solar cells.

PubMed

Pastore, Mariachiara; Duchanois, Thibaut; Liu, Li; Monari, Antonio; Assfeld, Xavier; Haacke, Stefan; Gros, Philippe C

2016-10-12

The first combined theoretical and photovoltaic characterization of both homoleptic and heteroleptic Fe(ii)-carbene sensitized photoanodes in working dye sensitized solar cells (DSSCs) has been performed. Three new heteroleptic Fe(ii)-NHC dye sensitizers have been synthesized, characterized and tested. Despite an improved interfacial charge separation in comparison to the homoleptic compounds, the heteroleptic complexes did not show boosted photovoltaic performances. The ab initio quantitative analysis of the interfacial electron and hole transfers and the measured photovoltaic data clearly evidenced fast recombination reactions for heteroleptics, even associated with un unfavorable directional electron flow, and hence slower injection rates, in the case of homoleptics. Notably, quantum mechanics calculations revealed that deprotonation of the not anchored carboxylic function in the homoleptic complex can effectively accelerate the electron injection rate and completely suppress the electron recombination to the oxidized dye. This result suggests that introduction of strong electron-donating substituents on the not-anchored carbene ligand in heteroleptic complexes, in such a way of mimicking the electronic effects of the carboxylate functionality, should yield markedly improved interfacial charge generation properties. The present results, providing for the first time a detailed understanding of the interfacial electron transfers and photovoltaic characterization in Fe(ii)-carbene sensitized solar cells, open the way to a rational molecular engineering of efficient iron-based dyes for photoelectrochemical applications.

Multimodal flow visualization and optimization of pneumatic blood pump for sorbent hemodialysis system.

PubMed

Shu, Fangjun; Parks, Robert; Maholtz, John; Ash, Steven; Antaki, James F

2009-04-01

Renal Solutions Allient Sorbent Hemodialysis System utilizes a two-chambered pneumatic pump (Pulsar Blood Pump, Renal Solutions, Inc., Warrendale, PA, USA) to avoid limitations associated with peristaltic pumping systems. Single-needle access is enabled by counter-pulsing the two pump chambers, thereby obviating compliance chambers or blood reservoirs. Each chamber propels 20 cc per pulse of 3 s (dual access) or 6 s (single access) duration, corresponding to a peak Reynolds number of approximately 8000 (based on inlet velocity and chamber diameter). A multimodal series of flow visualization studies (tracer particle, dye washout, and dye erosion) was conducted on a sequence of pump designs with varying port locations and diaphragms to improve the geometry with respect to risk of thrombogenesis. Experiments were conducted in a simplified flow loop using occluders to simulate flow resistance induced by tubing and dialyzer. Tracer visualization revealed flow patterns and qualitatively indicated turbulence intensity. Dye washout identified dwell volume and areas of flow stagnation for each design. Dye erosion results indicated the effectiveness and homogeneity of surface washing. Compared to a centered inlet which resulted in a fluid jet that produced two counter-rotating vortices, a tangential inlet introduced a single vortex, and kept the flow laminar. It also provided better surface washing on the pump inner surface. However, a tangential outlet did not present as much benefit as expected. On the contrary, it created a sharp defection to the flow when transiting from filling to ejection.

Use of dye tracing to determine ground-water movement to Mammoth Crystal Springs, Sylvan Pass area, Yellowstone National Park, Wyoming

USGS Publications Warehouse

Spangler, Lawrence E.; Susong, David D.

2006-01-01

At the request of and in cooperation with the Geology Program at Yellowstone National Park, the U.S. Geological Survey conducted a hydrologic investigation of the Sylvan Pass area in June 2005 to determine the relation between surface water and ground-water flow to Mammoth Crystal Springs. Results of a dye-tracing investigation indicate that streamflow lost into talus deposits on Sylvan Pass enters the ground-water system and moves to the southeast to discharge at Mammoth Crystal Springs. Ground-water travel times to the springs from a distance of 1.45 miles and a vertical relief of 500 feet were less than 1 day, indicating apparent rates of movement of at least 8,000 feet per day, values that are similar to those in karst aquifers. Peak dye concentrations were reached about 2 days after dye injection, and transit time of most of the dye mass through the system was about 3 weeks. High permeability and rapid travel times within this aquifer also are indicated by the large variation in springflow in response to snowmelt runoff and precipitation, and by the high concentration of suspended sediment (turbidity) in the water discharging into the spring-fed lake.

Extraction of dye from aqueous solution in rotating packed bed.

PubMed

Modak, Jayant B; Bhowal, Avijit; Datta, Siddhartha

2016-03-05

The influence of centrifugal acceleration on mass transfer rates in liquid-liquid extraction was investigated experimentally in rotating packed bed (RPB) contactor. The extraction of methyl red using xylene was studied in the equipment. The effect of rotational speed (300-900rpm), flow rate of the aqueous (4.17-20.8×10(-6)m(3)/s), and organic phase (0.83-2.5×10(-6)m(3)/s) on the mass transfer performance was examined. The maximum stage efficiency attained was ∼0.98 at aqueous to organic flow rate ratio of 10. The results suggest that contactor volume required to carry out a given separation can be reduced by an order of magnitude with RPB in comparison to conventional extractors. Copyright © 2015 Elsevier B.V. All rights reserved.

A rapid, reliable method of evaluating growth and viability of intraerythrocytic protozoan hemoparasites using fluorescence flow cytometry.

PubMed

Davis, W C; Wyatt, C R; Hamilton, M J; Goff, W L

1992-01-01

Fluorescence flow cytometry was employed to assess the potential of a vital dye, hydroethidine, for use in the detection and monitoring of the viability of hemoparasites in infected erythrocytes, using Babesia bovis as a model parasite. The studies demonstrated that hydroethidine is taken up by B. bovis and metabolically converted to the DNA binding fluorochrome, ethidium. Following uptake of the dye, erythrocytes containing viable parasites were readily distinguished and quantitated. Timed studies with the parasiticidal drug, Ganaseg, showed that it is possible to use the fluorochrome assay to monitor the effects of the drug on the rate of replication and viability of B. bovis in culture. The assay provides a rapid method for evaluation of the in vitro effect of drugs on hemoparasites and for analysis of the effect of various components of the immune response, such as lymphokines, monocyte products, antibodies, and effector cells (T, NK, LAK, ADCC) on the growth and viability of intraerythrocytic parasites.

A streaming birefringence study of the flow at the junction of the aorta and the renal arteries

NASA Astrophysics Data System (ADS)

Rankin, G. W.; Sabbah, H. N.; Stein, P. D.

1989-11-01

Streaming birefringence with an organic dye (Milling Yellow) was used to investigate the flow near the junction of the renal arteries and the descending aorta in a model of human vessels. The dye concentration was adjusted to give fluid rheological properties, typical of blood. Steady and pulsatile flow were investigated at branch-to-trunk flow ratios of 0.050 0.350. The flow ratio range over which flow separation and simple secondary flows were identified during systole near the renal ostia are reported. Streaming birefringence has the advantage of allowing visualization of the entire flow field. Also, the fluid rather than suspended particles are observed. An important disadvantage, however, is that three-dimensional flows make interpretation difficult.

Identification of runoff formation with two dyes in a mid-latitude mountain headwater

NASA Astrophysics Data System (ADS)

Vlcek, Lukas; Schneider, Philipp; Falatkova, Kristyna

2017-04-01

There have been numerous studies on subsurface flow in peat bog areas, as both water scarcity and floods have led to increased attention to this specific environment and its role within the hydrological cycle. In contrast, this experimental study identifies runoff formation at two opposite hillslopes in a peaty mountain headwater; a slope with organic soils (Peat / Histosol) and shallow groundwater ( 0.5 m below surface) complemented by a slope with mineral soils (Podzol) and no detectable groundwater within 2 m below surface. Differences in infiltration, percolation, and preferential flowpaths between both hillslopes could be identified by sprinkling experiments with two dyes - Brilliant Blue FCF and Fluorescein. By excavating dye-stained soil profiles parallel ("lateral") and perpendicular ("frontal") to the slopes' gradients - both within and downstream of the sprinkling plots - dye stained flow patterns in the soil could be clearly identified. The results show that biomat flow occurred at both hillslopes. The dye solutions infiltrated into the soil and continued either as lateral subsurface pipeflow (SSF), in the case of the Peat Bog, or percolated vertically towards the bedrock in the case of the Podzol. The study provides evidence that biomat flow (BMF) - shallow, lateral preferential flowpaths along decomposed tree roots or logs - is a major runoff formation process at the Peat Bog hillslope and in the adjacent riparian zone. This lateral flow through the organic soil hillslope (Peat Bog) towards the stream occurred mainly as shallow subsurface flow in organic layers above the groundwater level (BMF and SSF), but water partly percolates to the shallow groundwater via vertical macropores as well . In contrast, the mineral soil hillslope (Podzol) was mostly dominated by vertical percolation. Lateral flow occurred only on short distances in the organic topsoil as biomat flow (BMF). The sorptive tracer Brilliant Blue FCF successfully stained flowpaths in the soil at both hillslopes, whereas the identification of soil staining patterns by the relatively conservative tracer Fluorescein was limited on organic soil profiles.

[Characters of infiltration and preferential flow of black soil in Northeast China under different tillage patterns].

PubMed

Li, Wen-Feng; Zhang, Xiao-Ping; Liang, Ai-Zhen; Shen, Yan; Shi, Xiu-Huan; Luo, Jin-Ming; Yang, Xue-Ming

2008-07-01

By using dye tracer and double-ring infiltrometer techniques, the characters of infiltration and preferential flow of black soil under no-tillage (NT) and fall moldboard plow (MP) were compared after six years continuous management. The results showed that the infiltration rate was higher under NT than under MP. When the infiltration reached steady, the infiltration rate and accumulative infiltration capacity under NT were 1.35 and 1.44 times as high as those under MP, respectively. The penetration depth of methylene blue reached a depth of 43 cm in NT soil, being 16 cm deeper than that in MP soil. Comparing with MP soil, NT soil had better development of pore structure and more biological pores, and presented better preferential flow character, which were of importance for water infiltration and soil and water conservation.

Thermal modification of activated carbon surface chemistry improves its capacity as redox mediator for azo dye reduction.

PubMed

Pereira, L; Pereira, R; Pereira, M F R; van der Zee, F P; Cervantes, F J; Alves, M M

2010-11-15

The surface chemistry of a commercial AC (AC(0)) was selectively modified, without changing significantly its textural properties, by chemical oxidation with HNO(3) (AC(HNO3)) and O(2) (AC(O2)), and thermal treatments under H(2) (AC(H2)) or N(2) (AC(N2)) flow. The effect of modified AC on anaerobic chemical dye reduction was assayed with sulphide at different pH values 5, 7 and 9. Four dyes were tested: Acid Orange 7, Reactive Red 2, Mordant Yellow 10 and Direct Blue 71. Batch experiments with low amounts of AC (0.1 g L(-1)) demonstrated an increase of the first-order reduction rate constants, up to 9-fold, as compared with assays without AC. Optimum rates were obtained at pH 5 except for MY10, higher at pH 7. In general, rates increased with increasing the pH of point zero charge (pH(pzc)), following the trend AC(HNO3) < AC(O2) < AC(0) < AC(N2) < AC(H2). The highest reduction rate was obtained for MY10 with AC(H2) at pH 7, which corresponded to the double, as compared with non-modified AC. In a biological system using granular biomass, AC(H2) also duplicated and increase 4.5-fold the decolourisation rates of MY10 and RR2, respectively. In this last experiment, reaction rate was independent of AC concentration in the tested range 0.1-0.6 g L(-1). Copyright © 2010 Elsevier B.V. All rights reserved.

Rotating Rod Renewable Microcolumns for Automated, Solid-Phase DNA Hybridization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bruckner-Lea, Cynthia J.; Stottlemyre, Mark R.; Holman, David A.

1999-12-01

The development of a new temperature-controlled renewable microcolumn flow cell for solid-phase nucleic acid analysis in a sequential injection system is described. The flow cell includes a stepper motor-driven rotating rod with the working end cut to a 45 degree angle. In one position, the end of the rod prevents passage of microbeads while allowing fluid flow; rotation of the rod by 180 degrees release the beads. This system was used to rapidly test many hybridization and elution protocols to examine the temperature and solution conditions required for sequence specific nucleic acid hybridization. Target nucleic acids labeled with a near-infraredmore » fluorescent dye were detected immediately post-column using a flow-through fluorescence detector, with a detection limit of 40 pM dye concentration at a flow rate of 5 mu l/s. Temperature control of the column and the presence of Triton X-100 surfactant were critical for specific hybridization. Perfusion of the column with complementary oligonucleotide (200 mu l, 10nM) resulted in hybridization with 8% of the DNA binding sites on the microbeads with a solution residence time of less than a second and a total sample perfusion time of 40 seconds. The use of the renewable column system for detection of an unlabeled PCR product in a sandwich assay was also demonstrated.« less

Degradation of reactive blue 13 using hydrodynamic cavitation: Effect of geometrical parameters and different oxidizing additives.

PubMed

Rajoriya, Sunil; Bargole, Swapnil; Saharan, Virendra Kumar

2017-07-01

Decolorization of reactive blue 13 (RB13), a sulphonated azo dye, was investigated using hydrodynamic cavitation (HC). The aim of research article is to check the influence of geometrical parameters (total flow area, the ratio of throat perimeter to its cross-sectional area, throat shape and size, etc.) and configuration of the cavitating devices on decolorization of RB13 in aqueous solution. For this purpose, eight cavitating devices i.e. Circular and slit venturi, and six orifice plates having different flow area and perimeter were used in the present work. Initially, the effects of various operating parameters such as solution pH, initial dye concentration, operating inlet pressure and cavitation number on the decolorization of RB13 have been investigated, and the optimum operating conditions were found. Kinetic analysis revealed that the decolorization and mineralization of RB13 using HC followed first order reaction kinetics. Almost 47% decolorization of RB13 was achieved using only HC with slit venturi as a cavitating device at an optimum inlet pressure of 0.4MPa and pH of the solution as 2.0. It has been found that in case of orifice plates, higher decolorization rate of 4×10 -3 min -1 was achieved using orifice plate 2 (OP2) which is having higher flow area and perimeter (α=2.28). The effect of process intensifying agents (hydrogen peroxide and ferrous sulphate) and different gaseous additives (oxygen and ozone) on the extent of decolorization of RB13 were also examined. Almost 66% decolorization of RB13 was achieved using HC combined with 2Lmin -1 of oxygen and in combination with ferrous sulphate (1:3). Nearly 91% decolorization was achieved using HC combined with H 2 O 2 at an optimum molar ratio (dye:H 2 O 2 ) of 1:20 while almost complete decolorization was observed in 15min using a combination of HC and ozone at 3gh -1 ozone feed rate. Maximum 72% TOC was removed using HC coupled with 3gh -1 ozone feed rate. Copyright © 2017 Elsevier B.V. All rights reserved.

Infiltration in unsaturated layered fluvial deposits at Rio Bravo : photo essay and data summary.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brainard, James Robert; Glass, Robert John, Jr.

2007-08-01

An infiltration and dye transport experiment was conducted to visualize flow and transport processes in a heterogeneous, layered, sandy-gravelly fluvial deposit adjacent to Rio Bravo Boulevard in Albuquerque, NM. Water containing red dye followed by blue-green dye was ponded in a small horizontal zone ({approx}0.5 m x 0.5 m) above a vertical outcrop ({approx}4 m x 2.5 m). The red dye lagged behind the wetting front due to slight adsorption thus allowing both the wetting front and dye fronts to be observed in time at the outcrop face. After infiltration, vertical slices were excavated to the midpoint of the infiltrometermore » exposing the wetting front and dye distribution in a quasi three-dimensional manner. At small-scale, wetting front advancement was influenced by the multitude of local capillary barriers within the deposit. However at the scale of the experiment, the wetting front appeared smooth with significant lateral spreading {approx} twice that in the vertical, indicating a strong anisotropy due to the pronounced horizontal layering. The dye fronts exhibited appreciably more irregularity than the wetting front, as well as the influence of preferential flow features (a fracture) that moved the dye directly to the front, bypassing the fresh water between.« less

Calibration procedures for the quantitative determination of membrane potential in human cells using anionic dyes.

PubMed

Klapperstück, Thomas; Glanz, Dagobert; Hanitsch, Stefan; Klapperstück, Manuela; Markwardt, Fritz; Wohlrab, Johannes

2013-07-01

Quantitative determinations of the cell membrane potential of lymphocytes (Wilson et al., J Cell Physiol 1985;125:72-81) and thymocytes (Krasznai et al., J Photochem Photobiol B 1995;28:93-99) using the anionic dye DiBAC4 (3) proved that dye depletion in the extracellular medium as a result of cellular uptake can be negligible over a wide range of cell densities. In contrast, most flow cytometric studies have not verified this condition but rather assumed it from the start. Consequently, the initially prepared extracellular dye concentration has usually been used for the calculation of the Nernst potential of the dye. In this study, however, external dye depletion could be observed in both large IGR-1 and small LCL-HO cells under experimental conditions, which have often been applied routinely in spectrofluorimetry and flow cytometry. The maximum cell density at which dye depletion could be virtually avoided was dependent on cell size and membrane potential and definitely needed to be taken into account to ensure reliable results. In addition, accepted calibration procedures based on the partition of sodium and potassium (Goldman-Hodgkin-Katz equation) or potassium alone (Nernst equation) were performed by flow cytometry on cell suspensions with an appropriately low cell density. The observed extensive lack of concordance between the correspondingly calculated membrane potential and the equilibrium potential of DiBAC4 (3) revealed that these methods require the additional measurement of cation parameters (membrane permeability and/or intracellular concentration). In contrast, due to the linear relation between fluorescence and low DiBAC4 (3) concentrations, the Nernst potential of the dye for totally depolarized cells can be reliably used for calibration with an essentially lower effort and expense. Copyright © 2013 International Society for Advancement of Cytometry.

Chromatic shifts in the fluorescence emitted by murine thymocytes stained with Hoechst 33342.

PubMed

Petersen, Timothy W; Ibrahim, Sherrif F; Diercks, Alan H; van den Engh, Ger

2004-08-01

Many methods in flow cytometry rely on staining DNA with a fluorescent dye to gauge DNA content. From the relative intensity of the fluorescence signature, one can then infer position in cell cycle, amount of DNA (i.e., for sperm selection), or, as in the case of flow karyotyping, to distinguish individual chromosomes. This work examines the staining of murine thymocytes with a common DNA dye, Hoechst 33342, to investigate nonlinearities in the florescence intensity as well as chromatic shifts. Murine thymocytes were stained with Hoechst 33342 and measured in a flow cytometer at two fluorescence emission bands. In other measurements, cells were stained at different dye concentrations, and then centrifuged. The supernatant was then used for a second round of staining to test the amount of dye uptake. Finally, to test for resonant energy transfer, we measured fluorescence anisotropy at two different wavelengths. The fluorescence of cells stained with Hoechst 33342 is a nonlinear process that shows an overall decrease in intensity with increased dye uptake, and spectral shift to the red. Along with the spectral shift of the fluorescence to the longer wavelengths, we document decreases in the fluorescence anisotropy that may indicate resonant energy transfer. At low concentrations, Hoechst 33342 binds to the minor groove of DNA and shows an increase in fluorescence and a blue shift upon binding. At higher concentrations, at which the dye molecules can no longer bind without overlapping, the blue fluorescence decreases and the red fluorescence increases until there is approximately one dye molecule per DNA base pair. The ratio of the blue fluorescence to the red fluorescence is an accurate indicator of the cellular dye concentration.

Analysis of ground-water flow in the Madison aquifer using fluorescent dyes injected in Spring Creek and Rapid Creek near Rapid City, South Dakota, 2003-04

USGS Publications Warehouse

Putnam, Larry D.; Long, Andrew J.

2007-01-01

The Madison aquifer, which contains fractures and solution openings in the Madison Limestone, is used extensively for water supplies for the city of Rapid City and other suburban communities in the Rapid City, S. Dak., area. The 48 square-mile study area includes the west-central and southwest parts of Rapid City and the outcrops of the Madison Limestone extending from south of Spring Creek to north of Rapid Creek. Recharge to the Madison Limestone occurs when streams lose flow as they cross the outcrop. The maximum net loss rate for Spring and Rapid Creek loss zones are 21 and 10 cubic feet per second (ft3/s), respectively. During 2003 and 2004, fluorescent dyes were injected in the Spring and Rapid Creek loss zones to estimate approximate locations of preferential flow paths in the Madison aquifer and to measure the response and transit times at wells and springs. Four injections of about 2 kilograms of fluorescein dye were made in the Spring Creek loss zone during 2003 (sites S1, S2, and S3) and 2004 (site S4). Injection at site S1 was made in streamflow just upstream from the loss zone over a 12-hour period when streamflow was about equal to the maximum loss rate. Injections at sites S2, S3, and S4 were made in specific swallow holes located in the Spring Creek loss zone. Injection at site R1 in 2004 of 3.5 kilograms of Rhodamine WT dye was made in streamflow just upstream from the Rapid Creek loss zone over about a 28-hour period. Selected combinations of 27 wells, 6 springs, and 3 stream sites were monitored with discrete samples following the injections. For injections at sites S1-S3, when Spring Creek streamflow was greater than or equal to 20 ft3/s, fluorescein was detected in samples from five wells that were located as much as about 2 miles from the loss zone. Time to first arrival (injection at site S1) ranged from less than 1 to less than 10 days. The maximum fluorescein concentration (injection at site S1) of 120 micrograms per liter (ug/L) at well CO, which is located adjacent to the loss zone, was similar to the concentration in the stream. Fluorescein arrived at well NON (injection at site S1), which is located about 2 miles northeast of the loss zone, within about 1.6 days, and the maximum concentration was 44 ug/L. For injection at site S4, when streamflow was about 12 ft3/s, fluorescein was detected in samples from six wells and time to first arrival ranged from 0.2 to 16 days. Following injection at site S4 in 2004, the length of time that dye remained in the capture zone of well NON, which is located approximately 2 miles from the loss zone, was almost an order of magnitude greater than in 2003. For injection at site R1, Rhodamine WT was detected at well DRU and spring TI-SP with time to first arrival of about 0.5 and 1.1 days and maximum concentrations of 6.2 and 0.91 ug/L, respectively. Well DRU and spring TI-SP are located near the center of the Rapid Creek loss zone where the creek has a large meander. Measurable concentrations were observed for spring TI-SP as many as 109 days after the dye injection. The direction of a conduit flow path in the Spring Creek area was to the northeast with ground-water velocities that ranged from 770 to 6,500 feet per day. In the Rapid Creek loss zone, a conduit flow path east of the loss zone was not evident from the dye injection.

The Effects of Micromixing Two Solutions of Two Concentrations in a Two Tier PDMS Micromixer

NASA Astrophysics Data System (ADS)

Sundra, Sargunan; Fhong Soon, Chin; Zainal, Nurfarina; Sek Tee, Kian; Ahmad, Nornabihah; Gan, Siew Hua

2017-08-01

Micromixing technology has drastically advanced in the past few decades. Micromixers are one of the elements in integrated microfluidic systems for chemical, analytical chemistry, pharmaceutical, and biological applications. In this study, two tier micromixer was used to mix and dilute two solutions of similar and different concentration in order to investigate performance of micromixer’s mixing. This paper presents the fabrication of a designed micromixer using polydimethylsiloxane (PDMS) and vinyl tape methods which reduce time, cost and complexity of prototyping. The serpentine structure of the microchannels was designed to enhance both mixing and dilution. Two types of food dyes and distilled water were used to investigate the mixing performance of the micromixer followed by spectrophotometry analysis. It is observed that the single dye solution and distilled water shows better mixing performance compared to the micromixing of two dye solutions which was supported by the diffusion theory. 2.00 ml/min was the optimum flow rate that allow optimum mixing and dilution between two different concentrated liquids.

Growth of potassium sulfate crystals in the presence of organic dyes: in situ characterization by atomic force microscopy

NASA Astrophysics Data System (ADS)

Mauri, Andrea; Moret, Massimo

2000-01-01

In situ atomic force microscopy (AFM) has been used to observe potassium sulfate crystals growing in the presence of acid fuchsin and pyranine. These polysulfonated dyes are well known for their ability to adsorb onto the {1 1 0} and {0 1 0} (pyranine only) crystal faces. Using AFM, we analyzed the changes in surface micromorphology induced by the additives on advancing steps for the {1 1 0} and {0 1 0} surfaces. In situ AFM showed that layers grow by step flow at pre-existing steps by the addition of growth units at the step edges. It has been found that dye concentrations as low as ˜2×10 -6 M for pyranine and ˜4×10 -4 M for acid fuchsin produce significant changes in the step morphology and growth rates. The additive molecules attach to the terraces and pin the growing front. As a consequence, the edges of the growing steps become jagged as the dye molecules are adsorbed onto the crystal surface. At critical dye concentrations crystal growth is heavily hampered or even stopped along certain crystallographic directions producing, on a macroscopic scale, strong habit modifications. The formation of dye inclusions by means of macrosteps overgrowing the poisoned surface was also imaged. Interestingly, comparison of the in situ AFM experiments with previous habit modification studies showed acid fuchsin is also able to enter the {0 1 0} surfaces, a previously unnoticed phenomenon.

Preparation of demipermanent and semipermanent hair dyes gels from ethanol extract of Caesalpinia sappan L. using carbomer as gelling agent

NASA Astrophysics Data System (ADS)

Indrawati, T.; Syahrin, A.; Irpan

2017-07-01

Caesalpinia sappan L. (Cs L) contains of essential oils, saponin, brazilin, brazilein, alkaloids, flavonoids and tannins that have a function as cationic natural dyes. The aim of this research was to prepare the ethanol extract of Cs L wood and to prepare demi-permanent and semi-permanent of hair dye gels by using Carbomer of 2 % and 1.5 % as gelling agent and Cs L extract as cationic dyes. The Extract of Cs L was macerated by using ethanol of 96 % as the solvent, and then thickened. Three formula of demi-permanent hair dye gels were made by using Cs L extract of 3 %, 6% and 9 %. Three formula of semi-permanent hair dye gels were made by using Cs L extract of 2.50 %, 7.00 % and 10.50 %. Those hair dyes gels were prepared by swelling and mixing methods. All products of hair dyes gels were evaluated with organoleptic test, homogeneity test, pH test, consistency test, rheological properties test and dyeing effect test. The demi-permanent hair dye gels products had brown to brown dark black colors, pH of 5.05-5.43, homogeny, specific Cs L odor, and had pseudoplastic thixotropic flow characteristic. The semi-permanent hair dye gels products had red color pH of 6.5-6.25, homogeny, Cs L odor, and have pseudoplastic thixotropic flow characteristics. The optimum formula of demi-permanent was formula gel that contained of 6 % extract of Cs L and the optimum formula of permanent hair dyes gel was formula that contained of 10.50 % extract of Cs L.

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 Central

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

2011-01-01

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 (ICG, MB, and 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 CV and BG 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, 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

Automatic dilution gaging of rapidly varying flow

USGS Publications Warehouse

Duerk, M.D.

1983-01-01

The analysis showed that the discharges measured by dye-dilution techniques were generally within ± 10 percent of the discharges determined from ratings established by current-meter measurements. Larger differences were noted at the start of and on the rising limb of four hydrographs. Of the 20 storms monitored, dilution measurements on 17 were of acceptable accuracy. Peak discharges from the open-channel site ranged from 0 to 12 percent departures from the existing rating whereas the comparison of peak discharge at the storm sewer site ranged from 0 to 5 percent departures from the existing rating.

Observations from borehole dilution logging experiments in fractured crystalline rock under variable hydraulic conditions

USGS Publications Warehouse

Harte, Philip T.; Anderson, Alton; Williams, John H.

2014-01-01

Identifying hydraulically active fractures in low permeability, crystalline-bedrock aquifers requires a variety of geophysical and hydrogeophysical borehole tools and approaches. One such approach is Single Borehole Dilution Tests (SBDT), which in some low flow cases have been shown to provide greater resolution of borehole flow than other logging procedures, such as vertical differential Heat Pulse Flowmeter (HPFM) logging. Because the tools used in SBDT collect continuous profiles of water quality or dye changes, they can identify horizontal flow zones and vertical flow. We used SBDT with a food grade blue dye as a tracer and dual photometer-nephelometer measurements to identify low flow zones.SBDT were conducted at seven wells with open boreholes (exceeding 300 ft). At most of the wells HPFM logs were also collected. The seven wells are set in low-permeability, fractured granite and gneiss rocks underlying a former tetrachloroeythylene (PCE) source area at the Savage Municipal Well Superfund site in Milford, NH. Time series SBDT logs were collected at each of the seven wells under three distinct hydraulic conditions: (1) ambient conditions prior to a pump test at an adjacent well, (2) mid test, after 2-3 days of the start of the pump test, and (3) at the end of the test, after 8-9 days of the pump test. None of the SBDT were conducted under pumping conditions in the logged well. For each condition, wells were initially passively spiked with blue dye once and subsequent time series measurements were made.Measurement accuracy and precision of the photometer tool is important in SBDT when attempting to detect low rates of borehole flow. Tests indicate that under ambient conditions, none of the wells had detectable flow as measured with HPFM logging. With SBDT, 4 of the 7 showed the presence of some very low flow. None of 5 (2 of the 7 wells initially logged with HPFM under ambient conditions were not re-logged) wells logged with the HPFM during the pump test had detectable flow. However, 3 of the 5 wells showed the patterns of very low flow with SBDT during the pump test including pumping induced changes of inflow and outflow patterns at one well.

Identification of runoff formation with two dyes in a mid-latitude mountain headwater

NASA Astrophysics Data System (ADS)

Vlček, Lukáš; Falátková, Kristýna; Schneider, Philipp

2017-06-01

Subsurface flow in peat bog areas and its role in the hydrologic cycle has garnered increased attention as water scarcity and floods have increased due to a changing climate. In order to further probe the mechanisms in peat bog areas and contextualize them at the catchment scale, this experimental study identifies runoff formation at two opposite hillslopes in a peaty mountain headwater; a slope with organic peat soils and a shallow phreatic zone (0.5 m below surface), and a slope with mineral Podzol soils and no detectable groundwater (> 2 m below surface). Similarities and differences in infiltration, percolation and preferential flow paths between both hillslopes could be identified by sprinkling experiments with Brilliant Blue and Fluorescein sodium. To our knowledge, this is the first time these two dyes have been compared in their ability to stain preferential flow paths in soils. Dye-stained soil profiles within and downstream of the sprinkling areas were excavated parallel (lateral profiles) and perpendicular (frontal profiles) to the slopes' gradients. That way preferential flow patterns in the soil could be clearly identified. The results show that biomat flow, shallow subsurface flow in the organic topsoil layer, occurred at both hillslopes; however, at the peat bog hillslope it was significantly more prominent. The dye solutions infiltrated into the soil and continued either as lateral subsurface pipe flow in the case of the peat bog, or percolated vertically towards the bedrock in the case of the Podzol. This study provides evidence that subsurface pipe flow, lateral preferential flow along decomposed tree roots or logs in the unsaturated zone, is a major runoff formation process at the peat bog hillslope and in the adjacent riparian zone.

Production of Superoxide in Bacteria Is Stress- and Cell State-Dependent: A Gating-Optimized Flow Cytometry Method that Minimizes ROS Measurement Artifacts with Fluorescent Dyes.

PubMed

McBee, Megan E; Chionh, Yok H; Sharaf, Mariam L; Ho, Peiying; Cai, Maggie W L; Dedon, Peter C

2017-01-01

The role of reactive oxygen species (ROS) in microbial metabolism and stress response has emerged as a major theme in microbiology and infectious disease. Reactive fluorescent dyes have the potential to advance the study of ROS in the complex intracellular environment, especially for high-content and high-throughput analyses. However, current dye-based approaches to measuring intracellular ROS have the potential for significant artifacts. Here, we describe a robust platform for flow cytometric quantification of ROS in bacteria using fluorescent dyes, with ROS measurements in 10s-of-1000s of individual cells under a variety of conditions. False positives and variability among sample types (e.g., bacterial species, stress conditions) are reduced with a flexible four-step gating scheme that accounts for side- and forward-scattered light (morphological changes), background fluorescence, DNA content, and dye uptake to identify cells producing ROS. Using CellROX Green dye with Escherichia coli, Mycobacterium smegmatis , and Mycobacterium bovis BCG as diverse model bacteria, we show that (1) the generation of a quantifiable CellROX Green signal for superoxide, but not hydrogen peroxide-induced hydroxyl radicals, validates this dye as a superoxide detector; (2) the level of dye-detectable superoxide does not correlate with cytotoxicity or antibiotic sensitivity; (3) the non-replicating, antibiotic tolerant state of nutrient-deprived mycobacteria is associated with high levels of superoxide; and (4) antibiotic-induced production of superoxide is idiosyncratic with regard to both the species and the physiological state of the bacteria. We also show that the gating method is applicable to other fluorescent indicator dyes, such as the 5-carboxyfluorescein diacetate acetoxymethyl ester and 5-cyano-2,3-ditolyl tetrazolium chloride for cellular esterase and reductive respiratory activities, respectively. These results demonstrate that properly controlled flow cytometry coupled with fluorescent probes provides precise and accurate quantitative analysis of ROS generation and metabolic changes in stressed bacteria.

The state of the art of conventional flow visualization techniques for wind tunnel testing

NASA Technical Reports Server (NTRS)

Settles, G. S.

1982-01-01

Conventional wind tunnel flow visualization techniques which consist of surface flow methods, tracers, and optical methods are presented. Different surface flow methods are outlined: (1) liquid films (oil and fluorescent dye and UV lighting, renewable film via porous dispenser in model, volatile carrier fluid, cryogenic colored oil dots, oil film interferometry); (2) reactive surface treatment (reactive gas injection, reversible dye); (3) transition and heat transfer detectors (evaporation, sublimation, liquid crystals, phase change paints, IR thermography); and (4) tufts (fluorescent mini tufts, cryogenic suitability). Other methods are smoke wire techniques, vapor screens, and optical methods.

Effect of CO₂ flow rate on the Pinang frond-based activated carbon for methylene blue removal.

PubMed

Herawan, S G; Ahmad, M A; Putra, A; Yusof, A A

2013-01-01

Activated carbons are regularly used the treatment of dye wastewater. They can be produced from various organics materials having high level of carbon content. In this study, a novel Pinang frond activated carbon (PFAC) was produced at various CO₂ flow rates in the range of 150-600 mL/min at activation temperature of 800°C for 3 hours. The optimum PFAC sample is found on CO₂ flow rate of 300 mL/min which gives the highest BET surface area and pore volume of 958 m²/g and 0.5469 mL/g, respectively. This sample shows well-developed pore structure with high fixed carbon content of 79.74%. The removal of methylene blue (MB) by 95.8% for initial MB concentration of 50 mg/L and 72.6% for 500 mg/L is achieved via this sample. The PFAC is thus identified to be a suitable adsorbent for removing MB from aqueous solution.

Real-Time Monitoring of Azo Dye Interfacial Adsorption at Silica-Water Interface by Total Internal Reflection-Induced Surface Evanescent Wave.

PubMed

Xiong, Yan; Wang, Qing; Duan, Ming; Tan, Jun; Fang, Shenwen; Wu, Jiayi

2018-06-19

An interface research method based on total internal reflection induced evanescent wave (TIR-EW) is developed to monitor the adsorption behavior of azo dye at the silica-water interface. The monitoring system is constructed by employing silica optical fiber (SOF) as both charged substrate for dye adsorption and light transmission waveguide for evanescent wave production. According to the change of evanescent wave intensity and followed by Beer's law, the methylene blue (MB) adsorption behavior can be real-time monitored at the silica-water interface. Langmuir adsorption model and pseudo-first-order model are applied to obtain the related thermodynamic and kinetic data. The adsorption equilibrium constant ( K ads ) and adsorption free energy (Δ G) of MB at the silica-water interface are determined to be (3.3 ± 0.5) × 10 4 M -1 and -25.7 ± 1.7 kJ mol -1 . Meanwhile, this method is highlighted to isolate elementary processes of adsorption and desorption under steady-state conditions, and gives adsorption rate constant ( k a ) and desorption rate constant ( k d ) of 8585 ± 19.8 min -1 and 0.26 ± 0.0006 min -1 for 15 r/min flow rate. The surface interaction process is revealed and adsorption mechanism is proposed, indicating MB first adsorbed on Si-O - sites through electrostatic attraction and then on Si-OH sites through hydrogen bond with increasing MB concentrations. Our findings from this study provided molecular-level interpretation of azo dye adsorption at silica-water interface, and the results provide important insight into how MB adsorption can be controlled at the interface.

Continuous-wave organic dye lasers and methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shapira, Ofer; Chua, Song-Liang; Zhen, Bo

2014-09-16

An organic dye laser produces a continuous-wave (cw) output without any moving parts (e.g., without using flowing dye streams or spinning discs of solid-state dye media to prevent photobleaching) and with a pump beam that is stationary with respect to the organic dye medium. The laser's resonant cavity, organic dye medium, and pump beam are configured to excite a lasing transition over a time scale longer than the associated decay lifetimes in the organic dye medium without photobleaching the organic dye medium. Because the organic dye medium does not photobleach when operating in this manner, it may be pumped continuouslymore » so as to emit a cw output beam. In some examples, operation in this manner lowers the lasing threshold (e.g., to only a few Watts per square centimeter), thereby facilitating electrical pumping for cw operation.« less

Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system

NASA Astrophysics Data System (ADS)

Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

2016-04-01

In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m3·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment.

Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system

PubMed Central

Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

2016-01-01

In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m3·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment. PMID:27121278

Velocity, bathymetry, and transverse mixing characteristics of the Ohio River upstream from Cincinnati, Ohio, October 2004-March 2006

USGS Publications Warehouse

Koltun, G.F.; Ostheimer, Chad J.; Griffin, Michael S.

2006-01-01

Velocity, bathymetry, and transverse (cross-channel) mixing characteristics were studied in a 34-mile study reach of the Ohio River extending from the lower pool of the Captain Anthony Meldahl Lock and Dam, near Willow Grove, Ky, to just downstream from the confluence of the Licking and Ohio Rivers, near Newport, Ky. Information gathered in this study ultimately will be used to parameterize hydrodynamic and water-quality models that are being developed for the study reach. Velocity data were measured at an average cross-section spacing of about 2,200 feet by means of boat-mounted acoustic Doppler current profilers (ADCPs). ADCP data were postprocessed to create text files describing the three-dimensional velocity characteristics in each transect. Bathymetry data were measured at an average transect spacing of about 800 feet by means of a boat-mounted single-beam echosounder. Depth information obtained from the echosounder were postprocessed with water-surface slope and elevation information collected during the surveys to compute stream-bed elevations. The bathymetry data were written to text files formatted as a series of space-delimited x-, y-, and z-coordinates. Two separate dye-tracer studies were done on different days in overlapping stream segments in an 18.3-mile section of the study reach to assess transverse mixing characteristics in the Ohio River. Rhodamine WT dye was injected into the river at a constant rate, and concentrations were measured in downstream cross sections, generally spaced 1 to 2 miles apart. The dye was injected near the Kentucky shoreline during the first study and near the Ohio shoreline during the second study. Dye concentrations were measured along transects in the river by means of calibrated fluorometers equipped with flow-through chambers, automatic temperature compensation, and internal data loggers. The use of flow-through chambers permitted water to be pumped continuously out of the river from selected depths and through the fluorometer for measurement as the boat traversed the river. Time-tagged concentration readings were joined with horizontal coordinate data simultaneously captured from a differentially corrected Global Positioning System (GPS) device to create a plain-text, comma-separated variable file containing spatially tagged dye-concentration data. Plots showing the transverse variation in relative dye concentration indicate that, within the stream segments sampled, complete transverse mixing of the dye did not occur. In addition, the highest concentrations of dye tended to be nearest the side of the river from which the dye was injected. Velocity, bathymetry, and dye-concentration data collected during this study are available for Internet download by means of hyperlinks in this report. Data contained in this report were collected between October 2004 and March 2006.

Dynamic indocyanine green angiography measurements

NASA Astrophysics Data System (ADS)

Holmes, Timothy; Invernizzi, Alessandro; Larkin, Sean; Staurenghi, Giovanni

2012-11-01

Dynamic indocyanine green imaging uses a scanning laser ophthalmoscope and a fluorescent dye to produce movies of the dye-filling pattern in the retina and choroid of the eye. It is used for evaluating choroidal neovascularization. Movies are examined to identify the anatomy of the pathology for planning treatment and to evaluate progression or response to treatment. The popularity of this approach is affected by the complexity and difficulty in interpreting the movies. Software algorithms were developed to produce images from the movies that are easy to interpret. A mathematical model is formulated of the flow dynamics, and a fitting algorithm is designed that solves for the flow parameters. The images provide information about flow and perfusion, including regions of change between examinations. Imaged measures include the dye fill-time, temporal dispersion, and magnitude of the dye dilution temporal curves associated with image pixels. Cases show how the software can help to identify clinically relevant anatomy such as feeder vessels, drain vessels, capillary networks, and normal choroidal draining vessels. As a potential tool for research into the character of neovascular conditions and treatments, it reveals the flow dynamics and character of the lesion. Future varieties of this methodology may be used for evaluating the success of engineered tissue transplants, surgical flaps, reconstructive surgery, breast surgery, and many other surgical applications where flow, perfusion, and vascularity of tissue are important.

Sub-1min separation in sequential injection chromatography for determination of synthetic water-soluble dyes in pharmaceutical formulation.

PubMed

Davletbaeva, Polina; Chocholouš, Petr; Bulatov, Andrey; Šatínský, Dalibor; Solich, Petr

2017-09-05

Sequential Injection Chromatography (SIC) evolved from fast and automated non-separation Sequential Injection Analysis (SIA) into chromatographic separation method for multi-element analysis. However, the speed of the measurement (sample throughput) is due to chromatography significantly reduced. In this paper, a sub-1min separation using medium polar cyano monolithic column (5mm×4.6mm) resulted in fast and green separation with sample throughput comparable with non-separation flow methods The separation of three synthetic water-soluble dyes (sunset yellow FCF, carmoisine and green S) was in a gradient elution mode (0.02% ammonium acetate, pH 6.7 - water) with flow rate of 3.0mLmin -1 corresponding with sample throughput of 30h -1 . Spectrophotometric detection wavelengths were set to 480, 516 and 630nm and 10Hz data collection rate. The performance of the separation was described and discussed (peak capacities 3.48-7.67, peak symmetries 1.72-1.84 and resolutions 1.42-1.88). The method was represented by validation parameters: LODs of 0.15-0.35mgL -1 , LOQs of 0.50-1.25mgL -1 , calibration ranges 0.50-150.00mgL -1 (r>0.998) and repeatability at 10.0mgL -1 of RSD≤0.98% (n=6). The method was used for determination of the dyes in "forest berries" colored pharmaceutical cough-cold formulation. The sample matrix - pharmaceuticals and excipients were not interfering with vis determination because of no retention in the separation column and colorless nature. The results proved the concept of fast and green chromatography approach using very short medium polar monolithic column in SIC. Copyright © 2017 Elsevier B.V. All rights reserved.

Graphene-coated polystyrene-divinylbenzene dispersive solid-phase extraction coupled with supercritical fluid chromatography for the rapid determination of 10 allergenic disperse dyes in industrial wastewater samples.

PubMed

Lou, Chaoyan; Wu, Can; Zhang, Kai; Guo, Dandan; Jiang, Lei; Lu, Yang; Zhu, Yan

2018-05-18

Allergenic disperse dyes are a group of environmental contaminants, which are toxic and mutagenic to human beings. In this work, a method of dispersive solid-phase extraction (d-SPE) using graphene-coated polystyrene-divinylbenzene (G@PS-DVB) microspheres coupled with supercritical fluid chromatography (SFC) was proposed for the rapid determination of 10 allergenic disperse dyes in industrial wastewater samples. G@PS-DVB microspheres were synthesized by coating graphene (G) sheets onto polystyrene-divinylbenzene (PS-DVB) polymers. Such novel sorbents were employed in d-SPE for the purification and concentration of allergenic disperse dyes in wastewater samples prior to the determination by SFC with UV detection. To achieve the maximum extraction efficiency for the target dyes, several parameters influencing d-SPE process such as sorbent dosage, extraction time, desorption conditions were investigated. SFC conditions including stationary phase, modifier composition and percentage, column temperature, backpressure and flow rate were optimized to well separate the allergenic disperse dyes. Under the optimum conditions, satisfactory linear relationship (R ≥ 0.9989) was observed with the concentration of dyes ranging from 0.02 to 10.0 μg/mL. The limits of detection (LOD, S/N = 3) for the ten dyes were in the range of 1.1-15.6 ng/mL. Recoveries for the spiked samples were between 89.1% and 99.7% with relative standard deviations (RSD) lower than 10.5% in all cases. The proposed method is time-saving, green, precise and repeatable for the analysis of the target dyes. Furthermore, the application of G@PS-DVB based d-SPE process can be potentially expanded to isolate and concentrate other aromatic compounds in various matrices and supercritical fluid chromatography methodology featuring rapidity, accuracy and green will be an ideal candidate for the analysis of these compounds. Copyright © 2018 Elsevier B.V. All rights reserved.

Factors controlling charge recombination under dark and light conditions in dye sensitised solar cells.

PubMed

Barnes, Piers R F; Anderson, Assaf Y; Juozapavicius, Mindaugas; Liu, Lingxuan; Li, Xiaoe; Palomares, Emilio; Forneli, Amparo; O'Regan, Brian C

2011-02-28

A simple and powerful approach for assessing the recombination losses in dye sensitised solar cells (DSSCs) across the current voltage curve (j-V) as a function of TiO(2) electron concentration (n) is demonstrated. The total flux of electrons recombining with iodine species in the electrolyte and oxidised dye molecules can be thought of as a recombination current density, defined as j(rec) = j(inj)-j where j(inj) is the current of electrons injected from optically excited dye states and j is the current density collected at cell voltage (V). The electron concentration at any given operating conditions is determined by charge extraction. This allows comparison of factors influencing electron recombination rates at matched n. We show that j(rec) is typically 2-3 times higher under 1 sun equivalent illumination (j(inj) > 0) relative to dark (j(inj) = 0) conditions. This difference was increased by increasing light intensity, electrolyte iodine concentration and electrolyte solvent viscosity. The difference was reduced by increasing the electrolyte iodide concentration and increasing the temperature. These results allowed us to verify a numerical model of complete operational cells (Barnes et al., Phys. Chem. Chem. Phys., DOI: 10.1039/c0cp01554g) and to relate the differences in j(rec) to physical processes in the devices. The difference between j(rec) in the light and dark can be explained by two factors: (1) an increase in the concentration of electron acceptor species (I(3)(-) and/or I(2)) when current is flowing under illumination relative to dark conditions where the current is flowing in the opposite direction, and (2) a non-trivial contribution from electron recombination to oxidised dye molecules under light conditions. More generally, the technique helps to assign the observed relationship between the components, processing and performance of DSSCs to more fundamental physical processes.

Visualization studies of turbulent transition flows in a porous medium

NASA Technical Reports Server (NTRS)

Bilardo, V. J.

1983-01-01

Results are reported for flow-visualization studies of the flow regimes of water passing through a porous medium consisting of cylindrical glass and plexiglas rods arranged in a complex and fixed three-dimensional geometry. The Reynolds number (Re) varied from 50 to 700; the flow was visualized by injecting a 5% potassium permanganate dye solution into the pores and photographing the resulting dye streaklines with both a still camera and a movie camera. The results indicate that four distinct flow regimes exist in the porous medium: (1) Darcy or creeping flow up to Re = 3; (2) steady inertia-dominated laminar flow for Re = 3-150; (3) unsteady transitional laminar flow for Re = 150-250; and (4) fully turbulent flow for Re greater than 250. It is concluded that a laminar wake instability mechanism typical of the external flow about bluff bodies may be responsible for the overall transition from laminar to turbulent flow in porous media.

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

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

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. Copyright © 2011 International Society for Advancement of Cytometry.

ATP mediates flow-induced NO production in thick ascending limbs

PubMed Central

Hong, Nancy J.; Garvin, Jeffrey L.

2012-01-01

Mechanical stimulation caused by increasing flow induces nucleotide release from many cells. Luminal flow and extracellular ATP stimulate production of nitric oxide (NO) in thick ascending limbs. However, the factors that mediate flow-induced NO production are unknown. We hypothesized that luminal flow stimulates thick ascending limb NO production via ATP. We measured NO in isolated, perfused rat thick ascending limbs using the fluorescent dye DAF FM. The rate of increase in dye fluorescence reflects NO accumulation. Increasing luminal flow from 0 to 20 nl/min stimulated NO production from 17 ± 16 to 130 ± 37 arbitrary units (AU)/min (P < 0.02). Increasing flow from 0 to 20 nl/min raised ATP release from 4 ± 1 to 21 ± 6 AU/min (P < 0.04). Hexokinase (10 U/ml) plus glucose, which consumes ATP, completely prevented the measured increase in ATP. Luminal flow did not increase NO production in the presence of luminal and basolateral hexokinase (10 U/ml). When flow was increased with the ATPase apyrase in both luminal and basolateral solutions (5 U/ml), NO levels did not change significantly. The P2 receptor antagonist suramin (300 μmol/l) reduced flow-induced NO production by 83 ± 25% (P < 0.03) when added to both and basolateral sides. Luminal hexokinase decreased flow-induced NO production from 205.6 ± 85.6 to 36.6 ± 118.6 AU/min (P < 0.02). Basolateral hexokinase also reduced flow-induced NO production. The P2X receptor-selective antagonist NF023 (200 μmol/l) prevented flow-induced NO production when added to the basolateral side but not the luminal side. We conclude that ATP mediates flow-induced NO production in the thick ascending limb likely via activation of P2Y receptors in the luminal and P2X receptors in the basolateral membrane. PMID:22496412

Flow karyotyping and sorting of human chromosomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, J.W.; Lucas, J.; Peters, D.

1986-07-16

Flow cytometry and sorting are becoming increasingly useful as tools for chromosome classfication and for the detection of numerical and structural chromosome aberrations. Chromosomes of a single type can be purified with these tools to facilitate gene mapping or production of chromosome specific recombinant DNA libraries. For analysis of chromosomes with flow cytometry, the chromosomes are extracted from mitotic cells, stained with one or more fluorescent dyes and classified one-by-one according to their dye content(s). Thus, the flow approach is fundamentally different than conventional karyotyping where chromosomes are classified within the context of a metaphase spread. Flow sorting allows purificationmore » of chromosomes that can be distinguished flow cytometrically. The authors describe the basic principles of flow cytometric chromosome classification i.e. flow karyotyping, and chromosome sorting and describe several applications. 30 refs., 8 figs.« less

Basic dye decomposition kinetics in a photocatalytic slurry reactor.

PubMed

Wu, Chun-Hsing; Chang, Hung-Wei; Chern, Jia-Ming

2006-09-01

Wastewater effluent from textile plants using various dyes is one of the major water pollutants to the environment. Traditional chemical, physical and biological processes for treating textile dye wastewaters have disadvantages such as high cost, energy waste and generating secondary pollution during the treatment process. The photocatalytic process using TiO2 semiconductor particles under UV light illumination has been shown to be potentially advantageous and applicable in the treatment of wastewater pollutants. In this study, the dye decomposition kinetics by nano-size TiO2 suspension at natural solution pH was experimentally studied by varying the agitation speed (50-200 rpm), TiO2 suspension concentration (0.25-1.71 g/L), initial dye concentration (10-50 ppm), temperature (10-50 degrees C), and UV power intensity (0-96 W). The experimental results show the agitation speed, varying from 50 to 200 rpm, has a slight influence on the dye decomposition rate and the pH history; the dye decomposition rate increases with the TiO2 suspension concentration up to 0.98 g/L, then decrease with increasing TiO2 suspension concentration; the initial dye decomposition rate increases with the initial dye concentration up to a certain value depending upon the temperature, then decreases with increasing initial dye concentration; the dye decomposition rate increases with the UV power intensity up to 64 W to reach a plateau. Kinetic models have been developed to fit the experimental kinetic data well.

Isolation and Applications of Prostate Side Population Cells Based on Dye Cycle Violet Efflux

PubMed Central

Gangavarapu, Kalyan J.; Huss, Wendy J.

2011-01-01

This unit describes methods for the digestion of human prostate clinical specimens, dye cycle violet (DCV) staining procedure for the identification, isolation, and quantitation of radiolabeled dihydrotestosterone (DHT) retention of side population cells. The principle of the side population assay is based on differential efflux of DCV, a cell membrane permeable fluorescent dye, by cells with high ATP binding cassette (ABC) transporter activity. Cells with high ABC transporter activity efflux DCV and fall in the lower left quadrant of a flow cytograph are designated as “side population” cells. This unit emphasizes tissue digestion, DCV staining, flow settings for sorting side population cells and quantitation of radiolabeled DHT retention. PMID:21400686

Flow cytometric detection method for DNA samples

DOEpatents

Nasarabadi, Shanavaz [Livermore, CA; Langlois, Richard G [Livermore, CA; Venkateswaran, Kodumudi S [Round Rock, TX

2011-07-05

Disclosed herein are two methods for rapid multiplex analysis to determine the presence and identity of target DNA sequences within a DNA sample. Both methods use reporting DNA sequences, e.g., modified conventional Taqman.RTM. probes, to combine multiplex PCR amplification with microsphere-based hybridization using flow cytometry means of detection. Real-time PCR detection can also be incorporated. The first method uses a cyanine dye, such as, Cy3.TM., as the reporter linked to the 5' end of a reporting DNA sequence. The second method positions a reporter dye, e.g., FAM.TM. on the 3' end of the reporting DNA sequence and a quencher dye, e.g., TAMRA.TM., on the 5' end.

Flow cytometric detection method for DNA samples

DOEpatents

Nasarabadi, Shanavaz [Livermore, CA; Langlois, Richard G [Livermore, CA; Venkateswaran, Kodumudi S [Livermore, CA

2006-08-01

Disclosed herein are two methods for rapid multiplex analysis to determine the presence and identity of target DNA sequences within a DNA sample. Both methods use reporting DNA sequences, e.g., modified conventional Taqman.RTM. probes, to combine multiplex PCR amplification with microsphere-based hybridization using flow cytometry means of detection. Real-time PCR detection can also be incorporated. The first method uses a cyanine dye, such as, Cy3.TM., as the reporter linked to the 5' end of a reporting DNA sequence. The second method positions a reporter dye, e.g., FAM, on the 3' end of the reporting DNA sequence and a quencher dye, e.g., TAMRA, on the 5' end.

A study of the Coriolis effect on the fluid flow profile in a centrifugal bioreactor.

PubMed

Detzel, Christopher J; Thorson, Michael R; Van Wie, Bernard J; Ivory, Cornelius F

2009-01-01

Increasing demand for tissues, proteins, and antibodies derived from cell culture is necessitating the development and implementation of high cell density bioreactors. A system for studying high density culture is the centrifugal bioreactor (CCBR), which retains cells by increasing settling velocities through system rotation, thereby eliminating diffusional limitations associated with mechanical cell retention devices. This article focuses on the fluid mechanics of the CCBR system by considering Coriolis effects. Such considerations for centrifugal bioprocessing have heretofore been ignored; therefore, a simpler analysis of an empty chamber will be performed. Comparisons are made between numerical simulations and bromophenol blue dye injection experiments. For the non-rotating bioreactor with an inlet velocity of 4.3 cm/s, both the numerical and experimental results show the formation of a teardrop shaped plume of dye following streamlines through the reactor. However, as the reactor is rotated, the simulation predicts the development of vortices and a flow profile dominated by Coriolis forces resulting in the majority of flow up the leading wall of the reactor as dye initially enters the chamber, results are confirmed by experimental observations. As the reactor continues to fill with dye, the simulation predicts dye movement up both walls while experimental observations show the reactor fills with dye from the exit to the inlet. Differences between the simulation and experimental observations can be explained by excessive diffusion required for simulation convergence, and a slight density difference between dyed and un-dyed solutions. Implications of the results on practical bioreactor use are also discussed. (c) 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009.

A Study of the Coriolis Effect on the Fluid Flow Profile in a Centrifugal Bioreactor

PubMed Central

Detzel, Christopher J.; Thorson, Michael R.; Van Wie, Bernard J.; Ivory, Cornelius F.

2011-01-01

Increasing demand for tissues, proteins, and antibodies derived from cell culture is necessitating the development and implementation of high cell density bioreactors. A system for studying high density culture is the centrifugal bioreactor (CCBR) which retains cells by increasing settling velocities through system rotation, thereby eliminating diffusional limitations associated with mechanical cell retention devices. This paper focuses on the fluid mechanics of the CCBR system by considering Coriolis effects. Such considerations for centrifugal bioprocessing have heretofore been ignored; therefore a simpler analysis of an empty chamber will be performed. Comparisons are made between numerical simulations and bromophenol blue dye injection experiments. For the non-rotating bioreactor with an inlet velocity of 4.3 cm/s, both the numerical and experimental results show the formation of a teardrop shaped plume of dye following streamlines through the reactor. However, as the reactor is rotated the simulation predicts the development of vortices and a flow profile dominated by Coriolis forces resulting in the majority of flow up the leading wall of the reactor as dye initially enters the chamber, results confirmed by experimental observations. As the reactor continues to fill with dye, the simulation predicts dye movement up both walls while experimental observations show the reactor fills with dye from the exit to the inlet. Differences between the simulation and experimental observations can be explained by excessive diffusion required for simulation convergence, and a slight density difference between dyed and un-dyed solutions. Implications of the results on practical bioreactor use are also discussed. PMID:19455639

Combination of photocatalytic and membrane distillation hybrid processes for reactive dyes treatment.

PubMed

Yatmaz, H Cengiz; Dizge, Nadir; Kurt, Merve Sezen

2017-11-01

In this study, the degradation of azo dye solutions (Reactive Red 180 and Reactive Orange 16) of textile industry wastewater was investigated for using innovative hybrid process of photocatalytic and membrane distillation (MD) processes. Photocatalytic oxidation was conducted with semiconductor catalysts (ZnO and TiO2) and their mixture under UVA and UVC irradiation. More effective results were obtained under UVA at the initial stages of the reactions for both dye solutions. ZnO and TiO2 catalysts have given similar efficient results, but results with ZnO were better at initial stages. For the next stage, hybrid design of MD and photocatalytic processes was performed sequentially. Initially, the photocatalytic process was conducted for at least 1 h at initial values of 100 mg/L RR-180 dye solutions and 1 g/L ZnO catalyst loading under UVA irradiation and then treated solution was run through the distillation module at different temperatures (30°C and 40°C) and flow rates (210, 425, and 665 mL/min). Three types of membranes (polypropylene, polytetrafluoroethylene, and polyvinylidene fluoride) with different pore sizes (0.45 and 0.22 μm) were used in the module. Increasing temperature on the side of treated solution and decreasing the temperature on the other side has increased the distillate efficiency.

Characterization of Fluorescent Polystyrene Microspheres for Advanced Flow Diagnostics

NASA Technical Reports Server (NTRS)

Maisto, Pietro M. F.; Lowe, K. Todd; Byun, Guibo; Simpson, Roger; Vercamp, Max; Danley, Jason E.; Koh, Brian; Tiemsin, Pacita; Danehy, Paul M.; Wohl, Christopher J.

2013-01-01

Fluorescent dye-doped polystyrene latex microspheres (PSLs) are being developed for velocimetry and scalar measurements in variable property flows. Two organic dyes, Rhodamine B (RhB) and dichlorofluorescence (DCF), are examined to assess laser-induced fluorescence (LIF) properties for flow imaging applications and single-shot temperature measurements. A major interest in the current research is the application of safe dyes, thus DCF is of particular interest, while RhB is used as a benchmark. Success is demonstrated for single-point laser Doppler velocimetry (LDV) and also imaging fluorescence, excited via a continuous wave 2 W laser beam, for exposures down to 10 ms. In contrast, when exciting with a pulsed Nd:YAG laser at 200 mJ/pulse, no fluorescence was detected, even when integrating tens of pulses. We show that this is due to saturation of the LIF signal at relatively low excitation intensities, 4-5 orders of magnitude lower than the pulsed laser intensity. A two-band LIF technique is applied in a heated jet, indicating that the technique effectively removes interfering inputs such as particle diameter variation. Temperature measurement uncertainties are estimated based upon the variance measured for the two-band LIF intensity ratio and the achievable dye temperature sensitivity, indicating that particles developed to date may provide about +/-12.5 C precision, while future improvements in dye temperature sensitivity and signal quality may enable single-shot temperature measurements with sub-degree precision.

Comparison of static and shake culture in the decolorization of textile dyes and dye effluents by Phanerochaete chrysoporium.

PubMed

Sani, R K; Azmi, W; Banerjee, U C

1998-01-01

Decolorization of several dyes (Red HE-8B, Malachite Green, Navy Blue HE-2R, Magenta, Crystal Violet) and an industrial effluent with growing cells of Phanerochaete chrysosporium in shake and static culture was demonstrated. All the dyes and the industrial effluent were decolorized to some extent with varying percentages of decolorization (20-100%). The rate of decolorization was very rapid with Red HE-8B, an industrial dye. Decolorization rates for all the dyes in static condition were found to be less than the shake culture and also dependent on biomass concentration.

Measurements Of Coronary Mean Transit Time And Myocardial Tissue Blood Flow By Deconvolution Of Intravasal Tracer Dilution Curves

NASA Astrophysics Data System (ADS)

Korb, H.; Hoeft, A.; Hellige, G.

1984-10-01

Previous studies have shown that intramyocardial blood volume does not vary to a major extent even during extreme variation of hemodynamics and coronary vascular tone. Based on a constant intramyocardial blood volume it is therefore possible to calculate tissue blood flow from the mean transit time of an intravascular tracer. The purpose of this study was to develop a clinically applicable method for measurement of coronary blood flow. The new method was based on indocyanine green, a dye which is bound to albumin and intravasally detectable by means of a fiberoptic catheter device. One fiberoptic catheter was placed in the aortic root and another in the coronary sinus. After central venous dye injection the resulting arterial and coronary venous dye dilution curves were processed on-line by a micro-computer. The mean transit time as well as myocardial blood flow were calculated from the step response function of the deconvoluted arterial and coronary venous signals. Reference flow was determined with an extracorporeal electromagnetic flowprobe within a coronary sinus bypass system. 38 steady states with coronary blood flow ranging from 49 - 333 ml/min*100g were analysed in 5 dogs. Mean transit times varied from 2.9 to 16.6 sec. An average intracoronary blood volume of 13.9 -7 1.8 m1/100g was calculated. The correlation between flow determined by the dye dilution technique and flow measured with the reference method was 0.98. According to these results determination of coronary blood flow with a double fiberoptic system and indocyanine green should be possible even under clinical conditions. Furthermore, the arterial and coronary venous oxygen saturation can be monitored continuously by the fiberoptic catheters. Therefore, additional information about the performance of the heart such as myocardial oxygen consumption and myocardial efficiency is available with the same equipment.

Measurement of Zeta-Potential at Microchannel Wall by a Nanoscale Laser Induced Fluorescence Imaging

NASA Astrophysics Data System (ADS)

Kazoe, Yutaka; Sato, Yohei

A nanoscale laser induced fluorescence imaging was proposed by using fluorescent dye and the evanescent wave with total internal reflection of a laser beam. The present study focused on the two-dimensional measurement of zeta-potential at the microchannel wall, which is an electrostatic potential at the wall surface and a dominant parameter of electroosmotic flow. The evanescent wave, which decays exponentially from the wall, was used as an excitation light of the fluorescent dye. The fluorescent intensity detected by a CCD camera is closely related to the zeta-potential. Two kinds of fluorescent dye solution at different ionic concentrations were injected into a T-shaped microchannel, and formed a mixing flow field in the junction area. The two-dimensional distribution of zeta-potential at the microchannel wall in the pressure-driven flow field was measured. The obtained zeta-potential distribution has a transverse gradient toward the mixing flow field and was changed by the difference in the averaged velocity of pressure-driven flow. To understand the ion motion in the mixing flow field, the three-dimensional flow structure was analyzed by the velocity measurement using micron-resolution particle image velocimetry and the numerical simulation. It is concluded that the two-dimensional distribution of zeta-potential at the microchannel wall was dependent on the ion motion in the flow field, which was governed by the convection and molecular diffusion.

Spectroscopy and laser action of the "red perylimide dye" in various solvents

NASA Astrophysics Data System (ADS)

Gvishi, R.; Reisfeld, R.; Burshtein, Z.

1993-10-01

Optical properties of the red perylimide laser dye in various solvents are studied. The absorption spectrum exhibits two main bands, in the ranges 480-600 and 400-460 nm, due to the S 0-S 1 and S 0-S 2 transition. The fluorescence spectrum is a mirror image of the S 0-S 1 absorption (shift of ˜ 30-50 nm). The Stokes shift increases with solvent polarity. Such dye-solvent interactions are compared to theoretical predictions. The fluorescence quantum yields approaches unity in all the solvents studied. Laser tunability around 30 nm was obtained each time, covering the spectral range 580-640 nm. This interval is important for medical applications in photodynamic therapy and fluorescence diagnostics. The laser threshold energy varied from 0.35 mJ/pulse in cyclohexane to 1.87 mJ/pulse in methanol, and the slope efficiency from about 6.6% in methanol to 14% in xylenes. The laser output was stable for several hours of operation under an average pump energy of about 20 mJ/pulse at 1 Hz repetition rate, without flow.

Analysis of solvent dyes in refined petroleum products by electrospray ionization mass spectrometry

USGS Publications Warehouse

Rostad, C.E.

2010-01-01

Solvent dyes are used to color refined petroleum products to enable differentiation between gasoline, diesel, and jet fuels. Analysis for these dyes in the hydrocarbon product is difficult due to their very low concentrations in such a complex matrix. Flow injection analysis/electrospray ionization/mass spectrometry in both negative and positive mode was used to optimize ionization of ten typical solvent dyes. Samples of hydrocarbon product were analyzed under similar conditions. Positive electrospray ionization produced very complex spectra, which were not suitably specific for targeting only the dyes. Negative electrospray ionization produced simple spectra because aliphatic and aromatic moieties were not ionized. This enabled screening for a target dye in samples of hydrocarbon product from a spill.

Sonophotocatalytic degradation of trypan blue and vesuvine dyes in the presence of blue light active photocatalyst of Ag3PO4/Bi2S3-HKUST-1-MOF: Central composite optimization and synergistic effect study.

PubMed

Mosleh, S; Rahimi, M R; Ghaedi, M; Dashtian, K

2016-09-01

An efficient simultaneous sonophotocatalytic degradation of trypan blue (TB) and vesuvine (VS) using Ag3PO4/Bi2S3-HKUST-1-MOF as a novel visible light active photocatalyst was carried out successfully in a continuous flow-loop reactor equipped to blue LED light. Ag3PO4/Bi2S3-HKUST-1-MOF with activation ability under blue light illumination was synthesized and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), photoluminescence (PL) and diffuse reflectance spectra (DRS). The effect of operational parameters such as the initial TB and VS concentration (5-45mg/L), flow rate (30-110mL/min), irradiation and sonication time (10-30min), pH (3-11) and photocatalyst dosage (0.15-0.35g/L) has been investigated and optimized using central composite design (CCD) combined with desirability function (DF). Maximum sonophotodegradation percentage (98.44% and 99.36% for TB and VS, respectively) was found at optimum condition set as: 25mg/L of each dye, 70mL/min of solution flow rate, 25min of irradiation and sonication time, pH 6 and 0.25g/L of photocatalyst dosage. At optimum conditions, synergistic index value was obtained 2.53 that indicated the hybrid systems including ultrasound irradiation and photocatalysis have higher efficiency compared with sum of the individual processes. Copyright © 2016. Published by Elsevier B.V.

Photostability of low cost dye-sensitized solar cells based on natural and synthetic dyes

NASA Astrophysics Data System (ADS)

Abdou, E. M.; Hafez, H. S.; Bakir, E.; Abdel-Mottaleb, M. S. A.

2013-11-01

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 (η) 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.

Reversal in solvatochromism in some novel styrylpyridinium dyes having a hydrophobic cleft.

PubMed

Panigrahi, Mallika; Dash, Sukalyan; Patel, Sabita; Behera, P K; Mishra, B K

2007-11-01

The influence of solvent polarity on the electronic transition of four different N-hexadecyl styrylpyridinium dyes has been investigated in 15 solvents. The E(T)(30) scale has been used to propose a quantitative approach towards the relative stability of the electronic ground and excited state species. The extents of contribution of dipolar aprotic solvents towards the solvation of the excited species have been determined to be 42-48% for some of the dyes. Instead of a steady solvatochromism, all the dyes suffer a reversal in solvatochromism. The transitions of the solvatochromism, referred to as solvatochromic switches, are found to be at E(T)(30) values of approximately 50 for methyl and N,N-dimethylamino substituted dyes while at 37.6 for hydroxyl substituted dye and approximately 45 for 4-(1-methyl-2-phenylethenyl) pyridinium dye. A reversal in the trend of solvent effect in the later dye corresponding to 4-(4-methyl styryl)pyridinium dye has been attributed to an analogy of series and parallel electron flow.

Fixed-bed column performances of azure-II and auramine-O adsorption by Pinus eldarica stalks activated carbon and its composite with zno nanoparticles: Optimization by response surface methodology based on central composite design.

PubMed

Jafari, Maryam; Rahimi, Mahmood Reza; Ghaedi, Mehrorang; Javadian, Hamedreza; Asfaram, Arash

2017-12-01

A continuous adsorption was used for removal of azure II (AZ II) and auramine O (AO) from aqueous solutions using Pinus eldarica stalks activated carbon (PES-AC) from aqueous solutions. The effects of initial dye concentration, flow rate, bed height and contact time on removal percentage of AO and AZ II were evaluated and optimized by central composite design (CCD) at optimum pH = 7.0. ZnO nanoparticles loaded on activated carbon were also used to remove AO and AZ II at pH = 7.0 and other optimum conditions. The breakthrough curves were obtained at different flow rates, initial dye concentrations and bed heights and the experimental data were fitted by Thomas, Adams-Bohart and Yoon-Nelson models. The main parameters of fixed-bed column including its adsorption capacity at breakthrough point (q b ), adsorption capacity at saturation point (q s ), mass transfer zone (MTZ), total removal percentage (R%), and empty bed contact time (EBCT) were calculated. The removal percentages calculated for AZ II and AO II were in the range of 51.6-61.1% and 40.6-61.6%, respectively. Bed adsorption capacity (N 0 ) and critical bed depth (Z 0 ) were obtained by BDST model. Copyright © 2017 Elsevier Inc. All rights reserved.

Use of ground-water tracers to evaluate the hydraulic connection between Key Cave and the proposed industrial site near Florence, Alabama, 2000 and 2001

USGS Publications Warehouse

Kidd, Robert E.; Taylor, Charles J.; Stricklin, Victor E.

2001-01-01

In an effort to attract new industries and jobs, the city of Florence, Alabama has proposed development of an industrial park southwest of the city. Carbonate rock under-lines the area and sinkholes, springs, caves, and sinking streams are common. Key Cave, located about 5 miles southwest of the proposed park, is the only know habitat for the Alabama Cavefish (Speoplatyrhinus poulsoni). The Alabama Cavefish is a Federally designated Endangered Species, and Key Cave has been designated as Critical Habitat. The U.S. Geological Survey was requested by the city of Florence and the U.S. Fish and Wildlife Service to assist in determining if a hydraulic connection exists between the proposed industrial park and Key Cave. Dye tracing methods were used in the investigation to determine if a hydraulic connection exists. Dye tracing is a technique that involves labeling a discrete quantity of ground water with a fluorescent dye so that its flow in the subsurface can be tracked to a ground-water discharge point. Monitoring for dyes involved the use of passive dye detectors placed in springs, wells, caves and surface streams. During the passage of ground water containing fluorescent dye, the dye is absorbed and concentrated on the detectors. Spectrofluorometric analyses of the detectors determines the presence or absence of dye. Dye injected in well I-1 on January 10, 2001, was recovered from site 67, Cypress Creek at General John Coffee Highway (State Highway 20) on January 17, 2001. No dye was recovered from site 68, Cypress Creek at Waterloo Road (County Road 14), indicating an east-southeast flow path from well I-1 to Cypress Creek. No positive dye recovery was made from dye injected in well I-2 on January 10, 2001. Water samples collected from the well February 1 and 15, 2001, showed little movement into the ground-water system. Dye injected in well I-3 on January 10, 2001, was recovered at two sites in Key Cave and at other locations. This test indicates a hydraulic connection exists between Key Cave and the proposed industrial site.

Convection-Enhanced Transport into Open Cavities : Effect of Cavity Aspect Ratio.

PubMed

Horner, Marc; Metcalfe, Guy; Ottino, J M

2015-09-01

Recirculating fluid regions occur in the human body both naturally and pathologically. Diffusion is commonly considered the predominant mechanism for mass transport into a recirculating flow region. While this may be true for steady flows, one must also consider the possibility of convective fluid exchange when the outer (free stream) flow is transient. In the case of an open cavity, convective exchange occurs via the formation of lobes at the downstream attachment point of the separating streamline. Previous studies revealed the effect of forcing amplitude and frequency on material transport rates into a square cavity (Horner in J Fluid Mech 452:199-229, 2002). This paper summarizes the effect of cavity aspect ratio on exchange rates. The transport process is characterized using both computational fluid dynamics modeling and dye-advection experiments. Lagrangian analysis of the computed flow field reveals the existence of turnstile lobe transport for this class of flows. Experiments show that material exchange rates do not vary linearly as a function of the cavity aspect ratio (A = W/H). Rather, optima are predicted for A ≈ 2 and A ≈ 2.73, with a minimum occurring at A ≈ 2.5. The minimum occurs at the point where the cavity flow structure bifurcates from a single recirculating flow cell into two corner eddies. These results have significant implications for mass transport environments where the geometry of the flow domain evolves with time, such as coronary stents and growing aneurysms. Indeed, device designers may be able to take advantage of the turnstile-lobe transport mechanism to tailor deposition rates near newly implanted medical devices.

Adsorptive removal of direct azo dye from aqueous phase onto coal based sorbents: a kinetic and mechanistic study.

PubMed

Venkata Mohan, S; Chandrasekhar Rao, N; Karthikeyan, J

2002-03-01

This communication presents the results pertaining to the investigation conducted on color removal of trisazo direct dye, C.I. Direct Brown 1:1 by adsorption onto coal based sorbents viz. charfines, lignite coal, bituminous coal and comparing results with activated carbon (Filtrasorb-400). The kinetic sorption data indicated the sorption capacity of the different coal based sorbents. The sorption interaction of direct dye on to coal based sorbents obeys first-order irreversible rate equation and activated carbon fits with the first-order reversible rate equation. Intraparticle diffusion studies revealed the dye sorption interaction was complex and intraparticle diffusion was not only the rate limiting step. Isothermal data fit well with the rearranged Langmuir adsorption model. R(L) factor revealed the favorable nature of the isotherm of the dye-coal system. Neutral solution pH yielded maximum dye color removal. Desorption and interruption studies further indicated that the coal based sorbents facilitated chemisorption in the process of dye sorption while, activated carbon resulted in physisorption interaction.

Chromosome characterization using single fluorescent dye

DOEpatents

Crissman, Harry A.; Hirons, Gregory T.

1995-01-01

Chromosomes are characterized by fluorescent emissions from a single fluorescent dye that is excited over two different wavelengths. A mixture containing chromosomes is stained with a single dye selected from the group consisting of TOTO and YOYO and the stained chromosomes are placed in a flow cytometer. The fluorescent dye is excited sequentially by a first light having a wavelength in the ultraviolet range to excite the TOTO or YOYO to fluoresce at a first intensity and by a second light having a wavelength effective to excite the TOTO or YOYO dye to fluoresce at a second intensity. Specific chromosomes may be identified and sorted by intensity relationships between the first and second fluorescence emissions.

Photodecomposition of dyes on Fe-C-TiO(2) photocatalysts under UV radiation supported by photo-Fenton process.

PubMed

Tryba, B; Piszcz, M; Grzmil, B; Pattek-Janczyk, A; Morawski, A W

2009-02-15

Fe-C-TiO(2) photocatalysts were prepared by mechanical mixing of commercial anatase TiO(2) precursor with FeC(2)O(4) and heating at 500-800 degrees C under argon flow. These photocatalysts were tested for dyes decomposition: Methylene Blue (MB), Reactive Black (RB) and Acid Red (AR). The preliminary adsorption of dyes on the photocatalysts surface was performed. Modification of anatase by FeC(2)O(4) caused reducing of zeta potential of the photocatalyst surface from +12 to -7mV and decreasing of their adsorption ability towards RB and AR, which were negatively charged, -46.8 and -39.7, respectively. Therefore, unmodified TiO(2) showed the highest degree of RB and AR decompositions in the combination of dyes adsorption and UV irradiation. Methylene Blue, which had zeta potential of +4.3 in the aqueous solution was poorly adsorbed on all the tested photocatalysts and also slowly decomposed under UV irradiation. The high rate of dyes decomposition was noted on Fe-C-TiO(2) photocatalysts under UV irradiation with addition of H(2)O(2). It was observed, that at lower temperatures of heat treatment such as 500 degrees C higher content of carbon is remained in the sample, blocking the built in of iron into the TiO(2) lattice. This iron is reactive in the photo-Fenton process resulting in high production of OH radicals and also high activity of the photocatalyst. At higher temperatures of heat treatment, less active FeTiO(3) phase is formed, therefore Fe-C-TiO(2) sample prepared at 800 degrees C showed low photocatalytic activity for dyes decomposition. Fe-C-TiO(2) photocatalysts are active under visible light irradiation, however, the efficiency of a dye decomposition is lower than under UV light. In a dark Fenton process there is observed an insignificant generation of OH radicals and very little decomposition of a dye, what suggests the powerful of photo-Fenton process in the dyes decomposition.

Demonstration and Validation of a Fractured Rock Passive Flux Meter

DTIC Science & Technology

2015-04-01

impregnated with a visible dye . The core inflates separately from the two end packers to provide a mechanism for holding the one or ES-2 more reactive...typically 1 meter). Deploying the FRPFM in a borehole and exposing it to flowing groundwater for duration t [T] gradually leaches visible dyes and...tracers from the internal and external sorbent layers and produces residual dye and tracer distributions. Visual inspection of the external layer

KrF laser-induced OH fluorescence imaging in a supersonic combustion tunnel

NASA Technical Reports Server (NTRS)

Quagliaroli, T. M.; Laufer, G.; Hollo, S. D.; Krauss, R. H.; Whitehurst, R. B., III; Mcdaniel, J. C., Jr.

1992-01-01

Planar fluorescence images of OH in a continuous-flow, electrical-resistively heated, high enthalpy, hydrogen-air combustion tunnel, induced by a tunable KrF laser, were recorded. These images were compared to previously recorded fluorescence images induced by a doubled-dye laser under similar conditions. Images induced by the doubled-dye laser system demonstrated a severe distortion caused by absorption and fluorescence trapping. By contrast, images of the fluorescence induced by the tunable KrF laser retained the symmetry properties of the flow. Based on signal-to-noise ratio measurements the yield of the fluorescence induced by the doubled-dye laser is larger than the fluorescence yield induced by the KrF laser. The measurements in the present facility of OH fluorescence induced by the KrF laser were limited by the photon-statistical noise. Based 2 on this result, doubled-dye laser systems are recommended for OH imaging in small and OH lean (less than 10 exp 15/cu cm) facilities. KrF lasers should be selected otherwise.

Verification of a one-dimensional, unsteady-flow model for the Fox River in Illinois

USGS Publications Warehouse

Ishii, Audrey L.; Turner, Mary J.

1996-01-01

The previously-calibrated application of the Full EQuations (FEQ) model of one-dimensional, unsteady flow to a 30.7-mile reach of the Fox River in northeastern Illinois was verified with discharge, stage, and dye-transport data collected during a 12-day period in October-November 1990. The period included unsteady flow induced by the operation of a sluice gate dam located at the upstream end of the reach. The model flow field was input to the Branched Lagrangian Transport Model (BLTM) for the simulation of dye transport. The results of the FEQ and BLTM model simulations are compared with the measured data and sensitivity analyses of the model parameters for this application are presented.

Modeling highly transient flow, mass, and heat transport in the Chattahoochee River near Atlanta, Georgia

USGS Publications Warehouse

Jobson, Harvey E.; Keefer, Thomas N.

1979-01-01

A coupled flow-temperature model has been developed and verified for a 27.9-km reach of the Chattahoochee River between Buford Dam and Norcross, Ga. Flow in this reach of the Chattahoochee is continuous but highly regulated by Buford Dam, a flood-control and hydroelectric facility located near Buford, Ga. Calibration and verification utilized two sets of data collected under highly unsteady discharge conditions. Existing solution techniques, with certain minor improvements, were applied to verify the existing technology of flow and transport modeling. The linear, implicit finite-difference flow model was calibrated by use of a depth profile obtained at steady low flow and unsteady flow data obtained in March 1976. During the calibration period, the model was generally able to reproduce observed stages to within 0.15 m and discharges at less than 100 m 3 /s, to within 5 percent. Peak discharges of about 200 m 3 /s were under-estimated by about 20 percent. During the verification period, October 1975, the flow model reproduced observed stage changes to within about 0.15 m, and its timing and over-all performance was considered to be very good. Dye was added to the upstream end of the river reach at a constant rate while the river flow was highly unsteady. The numerical solution of either the conservative or nonconservative form of the mass-transport equation did an excellent job of simulating the observed concentrations of dye in the river. The temperature model was capable of predicting temperature changes through this reach of as large as 5.8?C with a RMS (root-mean-square) error of 0.32?C in October 1975 and 0.20?C in March 1976. Hydropulsation has a significant effect on the water temperature below Buford Dam. These effects are very complicated because they are quite dependent on the timing of the release with respect to both the time of day and past releases.

Analysis of nanoliter samples of electrolytes using a flow-through microfluorometer.

PubMed

Zhelyaskov, V R; Liu, S; Broderick, M P

2000-04-01

Several techniques have been developed to study the transport properties of nanoliter samples of renal tubule segments, such as continuous flow colorimetry and continuous fluorometry. We have extended the capability of the NANOFLO, a flow-through microfluorometer, designed for measurement of carbon dioxide, urea, ammonia, glucose, lactate, etc., to analyze sodium, calcium and chloride ions, using three commercially available fluorescent indicators for intracellular and extracellular measurements. The selection of fluorescent indicator for each electrolyte was dependent on the optimal match of the dissociation constant and the analyte concentration range of interest. Using Fluo-3 dye we achieved a detection limit for Ca2+ of 0.1 pmol and selectivity over Mg2+ of between 7:1 to 10:1. Using sodium green dye we achieved detection limit for Na+ of 12 pmol and a selectivity over K+ of 40:1. The detection limit for Cl- using lucigenin dye was 10 pmol. This technique can be readily adapted for the measurement of other physiologically important ultralow volume.

Preparation, Characterization of Coal Ash Adsorbent and Orthogonal Experimental Rsearch on Treating Printing and Dyeing Wastewater

NASA Astrophysics Data System (ADS)

Wang, Qingyu; He, Lingfeng; Shi, Liang; Chen, Xiaogang; Chen, Xin; Xu, Zizhen; Zhang, Yongli

2018-03-01

Using high temperature activated sodium flying ash and carboxymethyl chitosan as raw material to prepare carboxymethylchitosan wrapping fly-ash adsorbent (CWF), combined with iron-carbon micro-electrolysis treatment of simulated and actual printing and dyeing wastewater. The conditions for obtaining are from the literature: the best condition for CWF to treat simulated printing and dyeing wastewater pretreated with iron-carbon micro-electrolysis is that the mixing time is 10min, the resting time is 30 min, pH=6, and the adsorbent dosage is 0.75 g/L. The results showed that COD removal efficiency and decoloration rate were above 97 %, and turbidity removal rate was over 90 %. The optimum dyeing conditions were used to treat the dyeing wastewater. The decolorization rate was 97.30 %, the removal efficiency of COD was 92.44 %, and the turbidity removal rate was 90.37 %.

[Exclusive use of blue dye to detect sentinel lymph nodes in breast cancer].

PubMed

Bühler H, Simón; Rojas P, Hugo; Cayazzo M, Daniela; Cunill C, Eduardo; Vesperinas A, Gonzalo; Hamilton S, James

2008-08-01

The use of a dye and radiocolloid to detect sentinel lymph nodes in breast cancer increases the detection rates. However the use of either method alone does not modify the false negative rate. Therefore there is no formal contraindication for the exclusive use of dye to detect nodes. To report a prospective analysis of the exclusive blue dye technique for sentinel node biopsy in patients with early breast cancer. We analyzed the first 100 women with pathologically proven breast cancer who met the inclusion criteria. Patent blue dye was used as colorant. In the first 25 cases sentinel node was identified using radiocolloid and blue dye an then an axillary dissection performed. In the next 25 women, blue dye was used exclusively for detection and an axillary dissection was performed. In the next 50 cases, blue dye was used and only isolated sentinel node biopsy was performed. In 92 of the 100 women a sentinel node was successfully detected. In the first 50 women, the false negative rate of sentinel lymph node detection was 6.9%. No complications occurred. During follow-up, lasting three to 29 months, no axillary relapse was observed. Sentinel node biopsy in patients with early breast cancer using exclusively blue dye is feasible and safe.

Efficient removal of Acid Green 25 dye from wastewater using activated Prunus Dulcis as biosorbent: Batch and column studies.

PubMed

Jain, Suyog N; Gogate, Parag R

2018-03-15

Biosorbent synthesized from dead leaves of Prunus Dulcis with chemical activation during the synthesis was applied for the removal of Acid Green 25 dye from wastewater. The obtained biosorbent was characterized using Brunauer-Emmett-Teller analysis, Fourier transform-infrared spectroscopy and scanning electron microscopy measurements. It was demonstrated that alkali treatment during the synthesis significantly increased surface area of biosorbent from 67.205 to 426.346 m 2 /g. The effect of various operating parameters on dye removal was investigated in batch operation and optimum values of parameters were established as pH of 2, 14 g/L as the dose of natural biosorbent and 6 g/L as the dose of alkali treated biosorbent. Relative error values were determined to check fitting of obtained data to the different kinetic and isotherm models. It was established that pseudo-second order kinetic model and Langmuir isotherm fitted suitably to the obtained batch experimental data. Maximum biosorption capacity values were estimated as 22.68 and 50.79 mg/g for natural biosorbent and for alkali activated Prunus Dulcis, respectively. Adsorption was observed as endothermic and activation energy of 6.22 kJ/mol confirmed physical type of adsorption. Column experiments were also conducted to probe the effectiveness of biosorbent for practical applications in continuous operation. Breakthrough parameters were established by studying the effect of biosorbent height, flow rate of dye solution and initial dye concentration on the extent of dye removal. The maximum biosorption capacity under optimized conditions in the column operation was estimated as 28.57 mg/g. Thomas and Yoon-Nelson models were found to be suitably fitted to obtained column data. Reusability study carried out in batch and continuous column operations confirmed that synthesized biosorbent can be used repeatedly for dye removal from wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

Diazo dye Congo Red degradation using a Boron-doped diamond anode: An experimental study on the effect of supporting electrolytes.

PubMed

Jalife-Jacobo, H; Feria-Reyes, R; Serrano-Torres, O; Gutiérrez-Granados, S; Peralta-Hernández, Juan M

2016-12-05

Diazo dye Congo Red (CR) solutions at 100mg/L, were degraded using different supporting electrolytes in an electrochemical advanced oxidation process (EAOPs), like the anodic oxidation (AOx/BDD). All experiments were carried out in a 3L flow reactor with a Boron-doped diamond (BDD) anode and stainless steel cathode (AISI 304), at 7.5, 15, 30 and 50mA/cm(2) current densities (j). Furthermore, each experiment was carried out under a flow rate of 7L/min. Additionally, HClO4, NaCl, Na2SO4, and H2SO4 were tested as supporting electrolytes at a 50mM concentration. The degradation process was at all times considerably faster in NaCl medium. Solutions containing SO4(2-) or ClO4(-) ions were less prompted to degradation due to the low oxidation power of these species into the bulk. Dissolved organic carbon (DOC) analysis, was carried out to evaluate the mineralization of CR. The degradation of CR, was evaluated with the HPLC analysis of the treated solutions. Copyright © 2016 Elsevier B.V. All rights reserved.

Monolithic dye laser amplifier

DOEpatents

Kuklo, T.C.

1993-03-30

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.

Monolithic dye laser amplifier

DOEpatents

Kuklo, Thomas C.

1993-01-01

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.

Comparison of sentinel lymph node biopsy guided by blue dye with or without indocyanine green in early breast cancer.

PubMed

Shen, Songjie; Xu, Qianqian; Zhou, Yidong; Mao, Feng; Guan, Jinghong; Sun, Qiang

2018-05-22

There were limited data available for a head-to-head comparison of the identification rate and survival between the combined method of indocyanine green fluorescence and blue dye versus the traditional blue dye alone method for sentinel lymph node (SLN) biopsy. From January 2013 to December 2015, 523 eligible breast cancer patients were included in this nonrandomized prospective analysis. The identification rates, the number of SLNs identified, and the disease-free survival (DFS) between the two mapping methods were compared. The identification rate of SLNs was significantly higher with the combined method than that with the blue dye alone method (99.2% vs 93.3%, respectively; P < 0.001). The average number of SLNs identified per patient in the combined method group was 3.7 ± 2.4, which was more than that in the blue dye alone group (3.2 ± 1.6; P = 0.004). With a median follow-up of 29 months, 0.5% patients in the combined group, and 1.3% patients in the blue dye group had axillary recurrences. The DFS between the two groups showed no significant difference (P = 0.161). The combined method achieved a higher identification rate and lower rate of axillary recurrence compared to the blue dye alone method. © 2018 Wiley Periodicals, Inc.

Dye lasing arrangement including an optical assembly for altering the cross-section of its pumping beam and method

DOEpatents

O'Neil, Richard W.; Sweatt, William C.

1992-01-01

An optical assembly is disclosed herein along with a method of operation for use in a dye lasing arrangement, for example a dye laser oscillator or a dye amplifier, in which a continuous stream of dye is caused to flow through a given zone in a cooperating dye chamber while the zone is being illuminated by light from a pumping beam which is directed into the given zone. This in turn causes the dye therein to lase and thereby produce a new dye beam in the case of a dye laser oscillator or amplify a dye beam in the case of a dye amplifier. The optical assembly so disclosed is designed to alter the pump beam such that the beam enters the dye chamber with a different cross-sectional configuration, preferably one having a more uniform intensity profile, than its initially produced cross-sectional configuration. To this end, the assembly includes a network of optical components which first act on the beam while the latter retains its initially produced cross-sectional configuration for separating it into a plurality of predetermined segments and then recombines the separated components in a predetermined way which causes the recombined beam to have the different cross-sectional configuration.

Internal waves and rectification in a linearly stratified fluid

NASA Astrophysics Data System (ADS)

Pérenne, Nicolas; Renouard, Dominique P.

Laboratory experiments were performed in a 13-m diameter rotating tank equipped with a continuous shelf break geometry and a central piston-like plunger. The fluid density was linearly stratified. The amplitude and period of the plunger, the rotation rate of the platform and the stratification are the parameters of the problem. The density fluctuations at six stations above and at mid-depth of the slope, along with dye visualization of the flow, were recorded. A limited set of experiments showed that a barotropic periodical forcing generated a first mode baroclinic wave which initially appears at the slope and propagates offshore. The likely presence of internal energy rays either slightly above, or immediately along the slope, is in agreement with previous analytical, laboratory and selected oceanic observations. In the former case, the stratification was such that the slope flow at mid-depth was supercritical while in the latter case, slope flow at mid-depth was critical. Rotation tended to decrease the amplitude of the generated internal wave. Also, non-linear processes were likely to act upon these waves for their normalized amplitude tended to decrease as the forcing increased (for similar forcing period, rotation rate and stratification). After the internal wave reflected from the plunger reaches the slope, there is a complex non-stationary regime with an occurrence of internal wave breaking in the vicinity of the slope. Thus there was an appearance of localized patches of turbulence and mixing. These events appeared both in dye visualization and in density fluctuations records. The subsequent mixing, or else the combined effect of topographical rectification and mixing, led to the appearance of a distinct Lagrangian transport, localized in the first few centimeters above the slope and oriented so as to leave the shallow waters on the right of its displacement.

Impingement of Cloud Droplets on 36.5-Percent-Thick Joukowski Airfoil at Zero Angle of Attack and Discussion of Use as Cloud Measuring Instrument in Dye-Tracer Technique

NASA Technical Reports Server (NTRS)

Brun, R. J.; Vogt, Dorothea E.

1957-01-01

The trajectories of droplets i n the air flowing past a 36.5-percent-thick Joukowski airfoil at zero angle of attack were determined. The amount of water i n droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were calculated from the trajectories and cover a large range of flight and atmospheric conditions. With the detailed impingement information available, the 36.5-percent-thick Joukowski airfoil can serve the dual purpose of use as the principal element in instruments for making measurements in clouds and of a basic shape for estimating impingement on a thick streamlined body. Methods and examples are presented for illustrating some limitations when the airfoil is used as the principal element in the dye-tracer technique.

LANTHANIDE ENHANCE LUMINESCENCE (LEL) WITH ONE AND TWO PHOTON EXCITATION OF QUANTUM DYES LANTHANIDE (III) - MACROCYCLES

EPA Science Inventory

Title: Lanthanide Enhance Luminescence (LEL) with one and two photon excitation of Quantum Dyes? Lanthanide(III)-Macrocycles
Principal Author:
Robert C. Leif, Newport Instruments
Secondary Authors:
Margie C. Becker, Phoenix Flow Systems
Al Bromm, Virginia Commonw...

CALCULATION OF ELAPSED DECIMAL TIME FOR DYE-TRACING STUDIES: APPLICATION OF A BASELINE TIME STANDARD (Journal Article)

EPA Science Inventory

Calculation of time of travel from dye-tracing studies in karstic aquifers is critical to establishing pollutant arrival times from points of inflow to resurgences, calculation of subsurface flow velocities, and determining other important transport parameters such as longitudin...

Simultaneous three-dimensional velocity and mixing measurements by use of laser Doppler velocimetry and fluorescence probes in a water tunnel

NASA Technical Reports Server (NTRS)

Neuhart, Dan H.; Wing, David J.; Henderson, Uleses C., Jr.

1994-01-01

A water tunnel investigation was conducted to demonstrate the capabilities of a laser-based instrument that can measure velocity and fluorescence intensity simultaneously. Fluorescence intensity of an excited fluorescent dye is directly related to concentration level and is used to indicate the extent of mixing in flow. This instrument is a three-dimensional laser Doppler velocimeter (LDV) in combination with a fluorometer for measuring fluorescence intensity variations. This capability allows simultaneous flow measurements of the three orthogonal velocity components and mixing within the same region. Two different flows which were generated by two models were studied: a generic nonaxisymmetric nozzle propulsion simulation model with an auxiliary internal water source that generated a jet flow and an axisymmetric forebody model with a circular sector strake that generated a vortex flow. The off-body flow fields around these models were investigated in the Langley 16- by 24-Inch Water Tunnel. The experimental results were used to calculate 17 quantities that included mean and fluctuating velocities, Reynolds stresses, mean and fluctuating dye fluorescence intensities (proportional to concentration), and fluctuating velocity and dye concentration correlations. An uncertainty analysis was performed to establish confidence levels in the experimental results. In general, uncertainties in mean velocities varied between 1 and 7 percent of free-stream velocity; uncertainties in fluctuating velocities varied between 1 and 5 percent of reference values. The results show characteristics that are unique to each type of flow.

Characterization of vertical mixing in oscillatory vegetated flows

NASA Astrophysics Data System (ADS)

Abdolahpour, M.; Ghisalberti, M.; Lavery, P.; McMahon, K.

2016-02-01

Seagrass meadows are primary producers that provide important ecosystem services, such as improved water quality, sediment stabilisation and trapping and recycling of nutrients. Most of these ecological services are strongly influenced by the vertical exchange of water across the canopy-water interface. That is, vertical mixing is the main hydrodynamic process governing the large-scale ecological and environmental impact of seagrass meadows. The majority of studies into mixing in vegetated flows have focused on steady flow environments whereas many coastal canopies are subjected to oscillatory flows driven by surface waves. It is known that the rate of mass transfer will vary greatly between unidirectional and oscillatory flows, necessitating a specific investigation of mixing in oscillatory canopy flows. In this study, we conducted an extensive laboratory investigation to characterise the rate of vertical mixing through a vertical turbulent diffusivity (Dt,z). This has been done through gauging the evolution of vertical profiles of concentration (C) of a dye sheet injected into a wave-canopy flow. Instantaneous measurement of the variance of the vertical concentration distribution ( allowed the estimation of a vertical turbulent diffusivity (). Two types of model canopies, rigid and flexible, with identical heights and frontal areas, were subjected to a wide and realistic range of wave height and period. The results showed two important mechanisms that dominate vertical mixing under different conditions: a shear layer that forms at the top of the canopy and wake turbulence generated by the stems. By allowing a coupled contribution of wake and shear layer mixing, we present a relationship that can be used to predict the rate of vertical mixing in coastal canopies. The results further showed that the rate of vertical mixing within flexible vegetation was always lower than the corresponding rigid canopy, confirming the impact of plant flexibility on canopy-flow interactions.

Dye filled security seal

DOEpatents

Wilson, Dennis C. W.

1982-04-27

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.

High Power Dye Lasers

DTIC Science & Technology

1975-09-30

sphere is greatly reduced when compared to the axial flow dye cell. This is because the focusing optics can only direct light from a limited angle into...Distribution in Flashlamp . . . „ [ [ TTIH Flashlamp Cooling and Thermal Limits [ [ [ ii~ik Optical Characteristics ’,,: •*••••••••••• il-ib...Tracing Program e Dye Pumping System Laser Tests ! 1 i * * TTT’I Laser Output Fall Off !!!.’!!!" ’ TTT’H Single Shot Optical Distortion TTT’I

Solar photocatalytic degradation of mono azo methyl orange and diazo reactive green 19 in single and binary dye solutions: adsorbability vs photodegradation rate.

PubMed

Ong, Soon-An; Min, Ohm-Mar; Ho, Li-Ngee; Wong, Yee-Shian

2013-05-01

The objective of this study was to examine the effects of adsorbability and number of sulfonate group on solar photocatalytic degradation of mono azo methyl orange (MO) and diazo Reactive Green 19 (RG19) in single and binary dye solutions. The adsorption capacity of MO and RG19 onto the TiO₂ was 16.9 and 26.8 mg/g, respectively, in single dye solution, and reduced to 5.0 and 23.1 mg/g, respectively, in the binary dye solution. The data obtained for photocatalytic degradation of MO and RG19 in single and binary dye solution were well fitted with the Langmuir-Hinshelwood kinetic model. The pseudo-first-order rate constants of diazo RG19 were significant higher than the mono azo MO either in single or binary dye solutions. The higher number of sulfonate group in RG19 contributed to better adsorption capacity onto the surface of TiO₂ than MO indicating greater photocatalytic degradation rate.

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

PubMed

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

2002-06-10

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 could be well described by the Freundlich and Langmuir equations in the concentration range of 10-120 mg/l. An alkaline pH was favorable for the adsorption of dyes. Based on the adsorption capacity, it was shown that banana peel was more effective than orange peel. Kinetic parameters of adsorption such as the Langergren rate constant and the intraparticle diffusion rate constant were determined. For the present adsorption process intraparticle diffusion of dyes within the particle was identified to be rate limiting. Both peel wastes were shown to be promising materials for adsorption removal of dyes from aqueous solutions.

Decolorization pathways of anthraquinone dye Disperse Blue 2BLN by Aspergillus sp. XJ-2 CGMCC12963.

PubMed

Pan, Huiran; Xu, Xiaolin; Wen, Zhu; Kang, Yanshun; Wang, Xinhao; Ren, Youshan; Huang, Danqi

2017-09-03

Anthraquinone dye represents an important group of recalcitrant pollutants in dye wastewater. Aspergillus sp XJ-2 CGMCC12963 showed broad-spectrum decolorization ability, which could efficiently decolorize and degrade various anthraquinone dyes (50 mg L -1 ) under microaerophilic condition. And the decolorization rate of 93.3% was achieved at 120 h with Disperse Blue 2BLN (the target dye). Intermediates of degradation were detected by FTIR and GC-MS, which revealed the cleavage of anthraquinone chromophoric group and partial mineralization of target dye. In addition, extracellular manganese peroxidase showed the most closely related to the increasing of decolorization rate and biomass among intracellular and extracellular ligninolytic enzymes. Given these results, 2 possible degraded pathways of target dye by Aspergillus sp XJ-2 CGMCC12963 were proposed first in this work. The degradation of Disperse Blue 2BLN and broad spectrum decolorization ability provided the potential for Aspergillus sp XJ-2 CGMCC12963 in the treatment of wastewater containing anthraquinone dyes.

The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors.

PubMed

Akwi, Faith M; Watts, Paul

2016-01-01

In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 minutes and a small library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic systems. The scaled up synthesis of these compounds in PTFE tubing (i.d. 1.5 mm) was also investigated, where good reaction conversions ranging between 66-91% were attained.

Removal of dissolved textile dyes from wastewater by a compost sorbent

USGS Publications Warehouse

Tsui, L.S.; Roy, W.R.; Cole, M.A.

2003-01-01

The objective of this study was to evaluate the potential for treating dye-contaminated waste streams by sorption using compost as a low-cost sorbent. A mature, thermophilic compost sample was used to sorb CI Acid Black 24, CI Acid Orange 74, CI Basic Blue 9, CI Basic Green 4, CI Direct Blue 71, CI Direct Orange 39, CI Reactive Orange 16 and CI Reactive Red 2 from solution using a batch-sorption method. With the exception of the two reactive dyes, the sorption kinetics were favourable for a continuous-flow treatment process with the compost-dye mixtures reaching a steady state within 3-5 h. Based on limited comparisons, the affinity of the compost for each dye appeared to be competitive with other non-activated carbon sorbents. The results suggest that additional research on using compost as a sorbent for dye-contaminated solutions is warranted.

Calibration of a water-quality model for low-flow conditions on the Red River of the North at Fargo, North Dakota, and Moorhead, Minnesota, 2003

USGS Publications Warehouse

Lundgren, Robert F.; Nustad, Rochelle A.

2008-01-01

A time-of-travel and reaeration-rate study was conducted by the U.S. Geological Survey, in cooperation with the North Dakota Department of Health, the Minnesota Pollution Control Agency, and the cities of Fargo, North Dakota, and Moorhead, Minnesota, to provide information to calibrate a water-quality model for streamflows of less than 150 cubic feet per second. Data collected from September 24 through 27, 2003, were used to develop and calibrate the U.S. Environmental Protection Agency Water Quality Analysis Simulation Program model (hereinafter referred to as the Fargo WASP water-quality model) for a 19.2-mile reach of the Red River of the North. The Fargo WASP water-quality model was calibrated for the transport of dye by fitting simulated time-concentration dye curves to measured time-concentration dye curves. Simulated peak concentrations were within 10 percent of measured concentrations. Simulated traveltimes of the dye cloud centroid were within 7 percent of measured traveltimes. The variances of the simulated dye concentrations were similar to the variances of the measured dye concentrations, indicating dispersion was reproduced reasonably well. Average simulated dissolved-oxygen concentrations were within 6 percent of average measured concentrations. Average simulated ammonia concentrations were within the range of measured concentrations. Simulated dissolved-oxygen and ammonia concentrations were affected by the specification of a single nitrification rate in the Fargo WASP water-quality model. Data sets from August 1989 and August 1990 were used to test traveltime and simulation of dissolved oxygen and ammonia. For streamflows that ranged from 60 to 407 cubic feet per second, simulated traveltimes were within 7 percent of measured traveltimes. Measured dissolved-oxygen concentrations were underpredicted by less than 15 percent for both data sets. Results for ammonia were poor; measured ammonia concentrations were underpredicted by as much as 70 percent for both data sets. Overall, application of the Fargo WASP water-quality model to the 1989 and 1990 data sets resulted in poor agreement between measured and simulated concentrations. This likely is a result of changes in the waste-load composition for the Fargo and Moorhead wastewater-treatment plants as a result of improvements to the wastewater-treatment plants since 1990. The change in waste-load composition probably resulted in a change in decay rates and in dissolved oxygen no longer being substantially depressed downstream from the Moorhead and Fargo wastewater-treatment plants. The Fargo WASP water-quality model is valid for the current (2008) treatment processes at the wastewater-treatment plants.

Blue dye for identification of sentinel nodes in breast cancer and malignant melanoma: a systematic review and meta-analysis.

PubMed

Peek, Mirjam Cl; Charalampoudis, Petros; Anninga, Bauke; Baker, Rose; Douek, Michael

2017-02-01

The combined technique (radioisotope and blue dye) is the gold standard for sentinel lymph node biopsy (SLNB) and there is wide variation in techniques and blue dyes used. We performed a systematic review and meta-analysis to assess the need for radioisotope and the optimal blue dye for SLNB. A total of 21 studies were included. The SLNB identification rates are high with all the commonly used blue dyes. Furthermore, methylene blue is superior to iso-sulfan blue and Patent Blue V with respect to false-negative rates. The combined technique remains the most accurate and effective technique for SLNB. In order to standardize the SLNB technique, comparative trials to determine the most effective blue dye and national guidelines are required.

Combined biodegradation and ozonation for removal of tannins and dyes for the reduction of pollution loads.

PubMed

Kanagaraj, James; Mandal, Asit Baran

2012-01-01

Tannins and dyes pose major threat to the environment by generating huge pollution problem. Biodegradation of wattle extract, chrome tannin and dye compounds using suitable fungal culture namely Aspergillus niger, Penicillium sp. were carried out. In addition to these, ozone treatment was carried out to get higher degradation rate. The results were monitored by carrying out chemical oxygen demand (COD), total organic carbon (TOC), and UV-Vis analysis. The results showed that wattle extract (vegetable tannin) gave better biodegradation rate than dye and chromium compounds. Biodegradation plus ozone showed degradation rates of 92-95%, 94-95%, and 85-87% for the wattle extract, dyes, chromium compounds, respectively. UV-Vis showed that there were no peaks observed for biodegraded samples indicating better degradation rates as compared to the control samples. FT-IR spectra analysis suggested that the formation of flavanoid derivatives, chromic oxide and NH(2) compounds during degradation of wattle extract, chromium and dye compounds, respectively, at the peaks of 1,601-1,629 cm(-1), 1,647 cm(-1), and 1,610-1,680 cm(-1). The present investigation shows that combination of biodegradation with ozone is the effective method for the removal of dyes and tannins. The biodegradation of the said compounds in combination with ozonation showed better rate of degradation than by chemical methods. The combination of biodegradation with ozone helps to reduce pollution problems in terms of COD, TOC, total dissolved solids and total suspended solids.

Residualization Rates of Near Infrared Dyes for the Rational Design of Molecular Imaging Agents

PubMed Central

Cilliers, Cornelius; Liao, Jianshan; Atangcho, Lydia; Thurber, Greg M.

2016-01-01

Purpose Near infrared (NIR) fluorescence imaging is widely used for tracking antibodies and biomolecules in vivo. Clinical and preclinical applications include intraoperative imaging, tracking therapeutics, and fluorescent labeling as a surrogate for subsequent radiolabeling. Despite their extensive use, one of the fundamental properties of NIR dyes, the residualization rate within cells following internalization, has not been systematically studied. This rate is required for the rational design of probes and proper interpretation of in vivo results. Procedures In this brief report, we measure the cellular residualization rate of eight commonly used dyes encompassing three core structures (cyanine, BODIPY, and oxazine/thiazine/carbopyronin). Results We identify residualizing (half-life > 24 hrs) and non-residualizing dyes (half-life < 24 hrs) in both the far red (~650-680 nm) and near infrared (~740-800 nm) regions. Conclusions This data will allow researchers to independently and rationally select the wavelength and residualizing nature of dyes for molecular imaging agent design. PMID:25869081

Residualization Rates of Near-Infrared Dyes for the Rational Design of Molecular Imaging Agents.

PubMed

Cilliers, Cornelius; Liao, Jianshan; Atangcho, Lydia; Thurber, Greg M

2015-12-01

Near-infrared (NIR) fluorescence imaging is widely used for tracking antibodies and biomolecules in vivo. Clinical and preclinical applications include intraoperative imaging, tracking therapeutics, and fluorescent labeling as a surrogate for subsequent radiolabeling. Despite their extensive use, one of the fundamental properties of NIR dyes, the residualization rate within cells following internalization, has not been systematically studied. This rate is required for the rational design of probes and proper interpretation of in vivo results. In this brief report, we measure the cellular residualization rate of eight commonly used dyes encompassing three core structures (cyanine, boron-dipyrromethene (BODIPY), and oxazine/thiazine/carbopyronin). We identify residualizing (half-life >24 h) and non-residualizing (half-life <24 h) dyes in both the far-red (~650-680 nm) and near-infrared (~740-800 nm) regions. This data will allow researchers to independently and rationally select the wavelength and residualizing nature of dyes for molecular imaging agent design.

Rhodamine-WT dye losses in a mountain stream environment

USGS Publications Warehouse

Bencala, Kenneth E.; Rathburn, Ronald E.; Jackman, Alan P.; Kennedy, Vance C.; Zellweger, Gary W.; Avanzino, Ronald J.

1983-01-01

A significant fraction of rhodamine WT dye was lost during a short term multitracer injection experiment in a mountain stream environment. The conservative anion chloride and the sorbing cation lithium were concurrently injected. In-stream rhodamine WT concentrations were as low as 45 percent of that expected, based on chloride data. Concentration data were available from shallow‘wells’dug near the stream course and from a seep of suspected return flow. Both rhodamine WT dye and lithium were nonconservative with respect to the conservative chloride, with rhodamine WT dye closely following the behavior of the sorbing lithium.Nonsorption and sorption mechanisms for rhodamine WT loss in a mountain stream were evaluated in laboratory experiments. Experiments evaluating nonsorption losses indicated minimal losses by such mechanisms. Laboratory experiments using sand and gravel size streambed sediments show an appreciable capacity for rhodamine WT sorption.The detection of tracers in the shallow wells and seep indicates interaction between the stream and the flow in the surrounding subsurface, intergravel water, system. The injected tracers had ample opportunity for intimate contact with materials shown in the laboratory experiments to be potentially sorptive. It is suggested that in the study stream system, interaction with streambed gravel was a significant mechanism for the attenuation of rhodamine WT dye (relative to chloride).

Time of travel and dispersion of solutes in a 36.4-mile reach of the North Platte River downstream from Casper, Wyoming

USGS Publications Warehouse

Armentrout, G.W.; Larson, L.R.

1984-01-01

Time-of-travel and dispersion measurements made during a dye study November 7-8, 1978, are presented for a reach of the North Platte River from Casper, Wyo., to a bridge 2 miles downstream from below the Dave Johnston Power Plant. Rhodamine WT dye was injected into the river at Casper, and the resultant dye cloud was traced by sampling as it moved downstream. Samples were taken in three equal-flow sections of the river 's lateral transect at three sites, then analyzed in a fluorometer. The flow in the river was 940 cubic feet per second. The data consist of measured stream mileages and time, distance, and concentration graphs of the dye cloud. The peak concentration traveled through the reach in 24 hours, averaging 1.5 miles per hour; the leading edge took about 22 hours, averaging 1.7 miles per hour; and the trailing edge took 35 hours, averaging 1.0 mile per hour. Data from this study were compared with methods for estimating time of travel for a range of stream discharges.

Near-ultraviolet laser diodes for brilliant ultraviolet fluorophore excitation.

PubMed

Telford, William G

2015-12-01

Although multiple lasers are now standard equipment on most modern flow cytometers, ultraviolet (UV) lasers (325-365 nm) remain an uncommon excitation source for cytometry. Nd:YVO4 frequency-tripled diode pumped solid-state lasers emitting at 355 nm are now the primary means of providing UV excitation on multilaser flow cytometers. Although a number of UV excited fluorochromes are available for flow cytometry, the cost of solid-state UV lasers remains prohibitively high, limiting their use to all but the most sophisticated multilaser instruments. The recent introduction of the brilliant ultraviolet (BUV) series of fluorochromes for cell surface marker detection and their importance in increasing the number of simultaneous parameters for high-dimensional analysis has increased the urgency of including UV sources in cytometer designs; however, these lasers remain expensive. Near-UV laser diodes (NUVLDs), a direct diode laser source emitting in the 370-380 nm range, have been previously validated for flow cytometric analysis of most UV-excited probes, including quantum nanocrystals, the Hoechst dyes, and 4',6-diamidino-2-phenylindole. However, they remain a little-used laser source for cytometry, despite their significantly lower cost. In this study, the ability of NUVLDs to excite the BUV dyes was assessed, along with their compatibility with simultaneous brilliant violet (BV) labeling. A NUVLD emitting at 375 nm was found to excite most of the available BUV dyes at least as well as a UV 355 nm source. This slightly longer wavelength did produce some unwanted excitation of BV dyes, but at sufficiently low levels to require minimal additional compensation. NUVLDs are compact, relatively inexpensive lasers that have higher power levels than the newest generation of small 355 nm lasers. They can, therefore, make a useful, cost-effective substitute for traditional UV lasers in multicolor analysis involving the BUV and BV dyes. Published 2015 Wiley Periodicals Inc. on behalf of ISAC.

Particle Image Velocimetry Applications Using Fluorescent Dye-Doped Particles

NASA Technical Reports Server (NTRS)

Petrosky, Brian J.; Maisto, Pietro; Lowe, K. Todd; Andre, Matthieu A.; Bardet, Philippe M.; Tiemsin, Patsy I.; Wohl, Christopher J.; Danehy, Paul M.

2015-01-01

Polystyrene latex sphere particles are widely used to seed flows for velocimetry techniques such as Particle Image Velocimetry (PIV) and Laser Doppler Velocimetry (LDV). These particles may be doped with fluorescent dyes such that signals spectrally shifted from the incident laser wavelength may be detected via Laser Induced Fluorescence (LIF). An attractive application of the LIF signal is achieving velocimetry in the presence of strong interference from laser scatter, opening up new research possibilities very near solid surfaces or at liquid/gas interfaces. Additionally, LIF signals can be used to tag different fluid streams to study mixing. While fluorescence-based PIV has been performed by many researchers for particles dispersed in water flows, the current work is among the first in applying the technique to micron-scale particles dispersed in a gas. A key requirement for such an application is addressing potential health hazards from fluorescent dyes; successful doping of Kiton Red 620 (KR620) has enabled the use of this relatively safe dye for fluorescence PIV for the first time. In this paper, basic applications proving the concept of PIV using the LIF signal from KR620-doped particles are exhibited for a free jet and a twophase flow apparatus. Results indicate that while the fluorescence PIV techniques are roughly 2 orders of magnitude weaker than Mie scattering, they provide a viable method for obtaining data in flow regions previously inaccessible via standard PIV. These techniques have the potential to also complement Mie scattering signals, for example in multi-stream and/or multi-phase experiments.

Application of flow cytometry to wine microorganisms.

PubMed

Longin, Cédric; Petitgonnet, Clément; Guilloux-Benatier, Michèle; Rousseaux, Sandrine; Alexandre, Hervé

2017-04-01

Flow cytometry (FCM) is a powerful technique allowing detection and enumeration of microbial populations in food and during food process. Thanks to the fluorescent dyes used and specific probes, FCM provides information about cell physiological state and allows enumeration of a microorganism in a mixed culture. Thus, this technique is increasingly used to quantify pathogen, spoilage microorganisms and microorganisms of interest. Since one decade, FCM applications to the wine field increase greatly to determine population and physiological state of microorganisms performing alcoholic and malolactic fermentations. Wine spoilage microorganisms were also studied. In this review we briefly describe FCM principles. Next, a deep revision concerning enumeration of wine microorganisms by FCM is presented including the fluorescent dyes used and techniques allowing a yeast and bacteria species specific enumeration. Then, the last chapter is dedicated to fluorescent dyes which are used to date in fluorescent microscopy but applicable in FCM. This chapter also describes other interesting "future" techniques which could be applied to study the wine microorganisms. Thus, this review seeks to highlight the main advantages of the flow cytometry applied to wine microbiology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-modal in vivo imaging of brain blood oxygenation, blood flow and neural calcium dynamics during acute seizures

NASA Astrophysics Data System (ADS)

Ringuette, Dene; Jeffrey, Melanie A.; Carlen, Peter L.; Levi, Ofer

2016-03-01

Dysfunction of the vascular endothelium has been implicated in the development of epilepsy. To better understand the relation between vascular function and seizure and provide a foundation for interpreting results from functional imaging in chronic disease models, we investigate the relationship between intracellular calcium dynamics and local cerebral blood flow and blood oxygen saturation during acute seizure-like events and pharmacological seizure rescue. To probe the relation between the aforementioned physiological markers in an acute model of epilepsy in rats, we integrated three different optical modalities together with electrophysiological recordings: Laser speckle contrast imaging (LSCI) was used to study changes in flow speeds, Intrinsic optical signal imaging (IOSI) was used to monitor changes in oxygenated, de-oxygenated, and total hemoglobin concentration, and Calcium-sensitive dye imaging was used to monitor intracellular calcium dynamics. We designed a dedicated cortical flow chamber to remove superficial blood and dye resulting from the injection procedure, which reduced spurious artifacts. The near infrared light used for IOSI and LSCI was delivered via a light pipe integrated with the flow chamber to minimize the effect of fluid surface movement on illumination stability. Calcium-sensitive dye was injected via a glass electrode used for recording the local field potential. Our system allowed us to observe and correlate increases in intracellular calcium, blood flow and blood volume during seizure-like events and provide a quantitative analysis of neurovascular coupling changes associated with seizure rescue via injection of an anti-convulsive agent.

Visualization of Pulmonary Clearance Mechanisms via Noninvasive Optical Imaging Validated by Near-Infrared Flow Cytometry

PubMed Central

Zhou, Haiying; Gunsten, Sean P.; Zhegalova, Natalia G.; Bloch, Sharon; Achilefu, Samuel; Holley, J. Christopher; Schweppe, Daniel; Akers, Walter; Brody, Steven L.; Eades, William; Berezin, Mikhail Y.

2016-01-01

In vivo optical imaging with near-infrared (NIR) probes is an established method of diagnostics in preclinical and clinical studies. However, the specificities of these probes are difficult to validate ex vivo due to the lack of NIR flow cytometry. To address this limitation, we modified a flow cytometer to include an additional NIR channel using a 752 nm laser line. The flow cytometry system was tested using NIR microspheres and cell lines labeled with a combination of visible range and NIR fluorescent dyes. The approach was verified in vivo in mice evaluated for immune response in lungs after intratracheal delivery of the NIR contrast agent. Flow cytometry of cells obtained from the lung bronchoalveolar lavage demonstrated that the NIR dye was taken up by pulmonary macrophages as early as four-hours post-injection. This combination of optical imaging with NIR flow cytometry extends the capability of imaging and enables complementation of in vivo imaging with cell-specific studies. PMID:25808737

Free flow isotachophoresis in an injection moulded miniaturised separation chamber with integrated electrodes.

PubMed

Stone, Victoria N; Baldock, Sara J; Croasdell, Laura A; Dillon, Leonard A; Fielden, Peter R; Goddard, Nick J; Thomas, C L Paul; Treves Brown, Bernard J

2007-07-06

An injection moulded free flow isotachophoresis (FFITP) microdevice with integrated carbon fibre loaded electrodes with a separation chamber of 36.4mm wide, 28.7 mm long and 100 microm deep is presented. The microdevice was completely fabricated by injection moulding in carbon fibre loaded polystyrene for the electrodes and crystal polystyrene for the remainder of the chip and was bonded together using ultrasonic welding. Two injection moulded electrode designs were compared, one with the electrode surface level with the separation chamber and one with a recessed electrode. Separations of two anionic dyes, 0.2mM each of amaranth and acid green and separations of 0.2mM each of amaranth, bromophenol blue and glutamate were performed on the microdevice. Flow rates of 1.25 ml min(-1) for the leading and terminating electrolytes were used and a flow rate of 0.63 ml min(-1) for the sample. Electric fields of up to 370 V cm(-1) were applied across the separation chamber. Joule heating was not found to be significant although out-gassing was observed at drive currents greater than 3 mA.

Experimental quantification of solute transport through the vadose zone under dynamic boundary conditions with dye tracers and optical methods.

NASA Astrophysics Data System (ADS)

Cremer, Clemens; Neuweiler, Insa

2017-04-01

Knowledge of subsurface solute transport processes is vital to investigate e.g. groundwater contamination, nutrient uptake by plant roots and to implement remediation strategies. Beside field measurements and numerical simulations, physical laboratory experiments represent a way to establish process understanding and furthermore validate numerical schemes. Atmospheric forcings, such as erratically varying infiltration and evaporation cycles, subject the shallow subsurface to local and temporal variations in water content and associated hydraulic conductivity of the prevailing porous media. Those variations in material properties can cause flow paths to differ between upward and downward flow periods. Thereby, the unsaturated subsurface presents a highly complicated, dynamic system. Following an extensive systematical numerical investigation of flow and transport through bimodal, unsaturated porous media under dynamic boundary conditions (Cremer et al., 2016), we conduct physical laboratory experiments in a 22 cm x 8 cm x 1 cm flow cell where we introduce structural heterogeneity in the form sharp material interfaces between different porous media. In all experiments, a constant pressure head is implemented at the lower boundary, while cyclic infiltration-evaporation phases are applied at the soil surface. As a reference case a stationary infiltration with a rate corresponding to the cycle-averaged infiltration rate is applied. By initial application of dye tracers, solute transport within the domain is visualized such that transport paths and redistribution processes can be observed in a qualitative manner. Solute leaching is quantified at the bottom outlet, where breakthrough curves are obtained via spectroscopy. Liquid and vapor flow in and out of the domain is obtained from multiple balances. Thereby, the interplay of material structural heterogeneity and alternating flow (transport) directions and flow (transport) paths is investigated. Results show lateral transport through the material interface which differs between the stationary (unilateral) and dynamic cases (bilateral). This qualitative observation is confirmed by breakthrough curves for dynamic experiments which generally show the trend of faster initial breakthrough and increased tailing when compared to stationary infiltration results. Literature Cremer, C.J.M., I. Neuweiler, M. Bechtold, J. Vanderborght (2016): Solute Transport in Heterogeneous Soil with Time-Dependent Boundary Conditions, Vadose Zone Journal 15 (6) DOI: 10.2136/vzj2015.11.0144

Assessment of existing roadside swales with engineered filter soil: II. Treatment efficiency and in situ mobilization in soil columns.

PubMed

Ingvertsen, Simon T; Cederkvist, Karin; Jensen, Marina B; Magid, Jakob

2012-01-01

Use of roadside infiltration systems using engineered filter soil for optimized treatment has been common practice in Germany for decades, but little documentation is available regarding their long-term treatment performance. Here we present the results of laboratory leaching experiments with intact soil columns (15 cm i.d., 25-30 cm length) collected from two German roadside infiltration swales constructed in 1997. The columns were irrigated with synthetic solutions of unpolluted or polluted (dissolved heavy metals and fine suspended solids) road runoff, as well as a soluble nonreactive tracer (bromide) and a dye (brilliant blue). The experiments were performed at two irrigation rates corresponding to catchment rainfall intensities of approximately 5.1 and 34 mm/h. The bromide curves indicated that preferential flow was more pronounced at high irrigation rates, which was supported by the flow patterns revealed in the dye tracing experiment. Nonetheless, the soils seemed to be capable of retaining most of the dissolved heavy metals from the polluted road runoff at both low and high irrigation rates, except for Cr, which appears to pass through the soil as chromate. Fluorescent microspheres (diameter = 5 μm) used as surrogates for fine suspended solids were efficiently retained by the soils (>99%). However, despite promising treatment abilities, internal mobilization of heavy metals and P from the soil was observed, resulting in potentially critical effluent concentrations of Cu, Zn, and Pb. This is mainly ascribed to high concentrations of in situ mobilized dissolved organic carbon (DOC). Suggestions are provided for possible improvements and further research to minimize DOC mobilization in engineered filter soils. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

In silico designing of power conversion efficient organic lead dyes for solar cells using todays innovative approaches to assure renewable energy for future

NASA Astrophysics Data System (ADS)

Kar, Supratik; Roy, Juganta K.; Leszczynski, Jerzy

2017-06-01

Advances in solar cell technology require designing of new organic dye sensitizers for dye-sensitized solar cells with high power conversion efficiency to circumvent the disadvantages of silicon-based solar cells. In silico studies including quantitative structure-property relationship analysis combined with quantum chemical analysis were employed to understand the primary electron transfer mechanism and photo-physical properties of 273 arylamine organic dyes from 11 diverse chemical families explicit to iodine electrolyte. The direct quantitative structure-property relationship models enable identification of the essential electronic and structural attributes necessary for quantifying the molecular prerequisites of 11 classes of arylamine organic dyes, responsible for high power conversion efficiency of dye-sensitized solar cells. Tetrahydroquinoline, N,N'-dialkylaniline and indoline have been least explored classes under arylamine organic dyes for dye-sensitized solar cells. Therefore, the identified properties from the corresponding quantitative structure-property relationship models of the mentioned classes were employed in designing of "lead dyes". Followed by, a series of electrochemical and photo-physical parameters were computed for designed dyes to check the required variables for electron flow of dye-sensitized solar cells. The combined computational techniques yielded seven promising lead dyes each for all three chemical classes considered. Significant (130, 183, and 46%) increment in predicted %power conversion efficiency was observed comparing with the existing dye with highest experimental %power conversion efficiency value for tetrahydroquinoline, N,N'-dialkylaniline and indoline, respectively maintaining required electrochemical parameters.

Use of LysoTracker dyes: a flow cytometric study of autophagy.

PubMed

Chikte, Shaheen; Panchal, Neelam; Warnes, Gary

2014-02-01

The flow cytometric use of LysoTracker dyes was employed to investigate the autophagic process and to compare this with the upregulation of autophagy marker, the microtubule-associated protein LC3B. Although the mechanism of action of LysoTracker dyes is not fully understood, they have been used in microscopy to image acidic spherical organelles, and their use in flow cytometry has not been thoroughly investigated in the study of autophagy. This investigation uses numerous autophagy-inducing agents including chloroquine (CQ), rapamycin, low serum (<1%) RPMI, and nutrient starvation to induce autophagy in Jurkat T-cell leukemia and K562 erythromyeloid cell lines. LC3B showed an increase with CQ treatment although this was different to LysoTracker signals in terms of dose and time. Rapamycin, low serum (<1%) RPMI, and nutrient starvation induction of autophagy also induced an increase in LysoTracker and LC3B signals. CQ also induced apoptosis in cell lines, which was blocked by pan-caspase inhibitor z-VAD resulting in a reduction in cells undergoing apoptosis and a subsequent upregulation of autophagic markers LC3B and lysosomal dye signals. Given that LC3B and LysoTracker are measuring different biological events in the autophagic process, they surprisingly both upregulated during autophagic process. This study, however, shows that although LysoTracker dyes do not specifically label lysosomes or autophagosomes within the cell, they allow the simultaneous measurement of an autophagy-related process and other live-cell functions, which are not possible with the standard LC3B antibody-labeling technique. This method has the advantage of other live-cell LCB-GFP-tagged experiments in that be used to analyze patient cells as well as easier to use and significantly less costly. Copyright © 2013 International Society for Advancement of Cytometry.

On-line SPE-UHPLC method using fused core columns for extraction and separation of nine illegal dyes in chilli-containing spices.

PubMed

Khalikova, Maria A; Satínský, Dalibor; Smidrkalová, Tereza; Solich, Petr

2014-12-01

The presented work describes the development of a simple, fast and effective on-line SPE-UHPLC-UV/vis method using fused core particle columns for extraction, separation and quantitative analysis of the nine illegal dyes, most frequently found in chilli-containing spices. The red dyes Sudan I-IV, Sudan Red 7B, Sudan Red G, Sudan Orange G, Para Red, and Methyl Red were separated and analyzed in less than 9 min without labor-consuming pretreatment procedure. The chromatographic separation was performed on Ascentis Express RP-Amide column with gradient elution using mixture of acetonitrile and water, as a mobile phase at a flow rate of 1.0 mL min(-1) and 55°C of temperature. As SPE sorbent for cleanup and pre-concentration of illegal dyes short guard fused core column Ascentis Express F5 was used. The applicability of proposed method was proven for three different chilli-containing commercial samples. Recoveries for all compounds were between 90% and 108% and relative standard deviation ranged from 1% to 4% for within- and from 2% to 6% for between-day. Limits of detection showed lower values than required by European Union regulations and were in the range of 3.3-10.3 µg L(-1) for standard solutions, 5.6-235.6 µg kg(-1) for chilli-containing spices. Copyright © 2014 Elsevier B.V. All rights reserved.

Time of travel of the Flint River, Utah Dam to highway M-13, Michigan, August 4-8, 1981

USGS Publications Warehouse

Cummings, T. Ray; Miller, John B.

1982-01-01

Tracing of rhodamine WT dye has provided time-of-travel data for waste-load allocation studies of a 42.8-mile reach of the Flint River at low flow. A discharge equaled or exceeded about 90 percent of the time was measured at Grand Traverse Street in Flint before dye injection. Dye was injected at two locations in Flint--at Utah Dam and at Grand Traverse Street, From Utah Dam to Grand Traverse Street, the mean velocity of flow was about 0.1 foot per second; time-of-travel was 35.3 hours. From Grand Traverse Street to Highway M-13, mean velocity was about 0.7 foot per second; time-of-travel was 78.8 hours. Time-of-travel for the reach between Utah Dam and Highway M-13 was thus 114 hours.

Efficient 7-J flashlamp-pumped dye laser at 500-nm wavelength

DOE Office of Scientific and Technical Information (OSTI.GOV)

Everett, P.N.; Aldag, H.R.; Ehrlich, J.J.

1986-07-01

An existing transverse flow flashlamp-pumped dye laser capable of operation at 500 pps for extended periods of time has been modified and optimized for operation at 502 nm using coumarin 504. Energies of over 7 J/ pulse and efficiencies of over 1% have been demonstrated in single-shot operation. This has been achieved by using a spectral transfer dye in the flashlamp coolant to increase the useful output of the flashlamps. Flashlamps were tested at up to 400-J input per lamp for extended periods to develop lamp life data.

Infiltration pattern in a regolith-fractured bedrock profile: field observation of a dye stain pattern

NASA Astrophysics Data System (ADS)

Kim, Jae Gon; Lee, Gyoo Ho; Lee, Jin-Soo; Chon, Chul-Min; Kim, Tack Hyun; Ha, Kyoochul

2006-02-01

We examined the infiltration pattern of water in a regolith-bedrock profile consisting of two overburdens (OB1 and OB2), a buried rice paddy soil (PS), two texturally distinctive weathered materials (WM1 and WM2) and a fractured sedimentary rock (BR), using a Brilliant Blue FCF dye tracer. A black-coloured coating in conducting fractures in WM1, WM2 and BR was analysed by X-ray diffraction and scanning electron microscopy. The dye tracer penetrated to greater than 2 m depth in the profile. The macropore flow and saturated interflow were the major infiltration patterns in the profile. Macropore flow and saturated interflow were observed along fractures in WM1, WM2 and BR and at the dipping interfaces of PS-WM1, PS-WM2 and PS-BR respectively. Heterogeneous matrix flow occurred in upper overburden (OB1) and PS. Compared with OB1, the coarser textured OB2 acted as a physical barrier for vertical flow of water. The PS with low bulk density and many fine roots was another major conducting route of water in the profile. Manganese oxide and iron oxide were positively identified in the black coating material and had low crystallinity and high surface area, indicating their high reactivity with conducting contaminants.

Microbial fuel cell operation using monoazo and diazo dyes as terminal electron acceptor for simultaneous decolourisation and bioelectricity generation.

PubMed

Oon, Yoong-Sin; Ong, Soon-An; Ho, Li-Ngee; Wong, Yee-Shian; Oon, Yoong-Ling; Lehl, Harvinder Kaur; Thung, Wei-Eng; Nordin, Noradiba

2017-03-05

Monoazo and diazo dyes [New coccine (NC), Acid orange 7 (AO7), Reactive red 120 (RR120) and Reactive green 19 (RG19)] were employed as electron acceptors in the abiotic cathode of microbial fuel cell. The electrons and protons generated from microbial organic oxidation at the anode which were utilized for electrochemical azo dye reduction at the cathodic chamber was successfully demonstrated. When NC was employed as the electron acceptor, the chemical oxygen demand (COD) removal and dye decolourisation efficiencies obtained at the anodic and cathodic chamber were 73±3% and 95.1±1.1%, respectively. This study demonstrated that the decolourisation rates of monoazo dyes were ∼50% higher than diazo dyes. The maximum power density in relation to NC decolourisation was 20.64mW/m 2 , corresponding to current density of 120.24mA/m 2 . The decolourisation rate and power output of different azo dyes were in the order of NC>AO7>RR120>RG19. The findings revealed that the structure of dye influenced the decolourisation and power performance of MFC. Azo dye with electron-withdrawing group at para substituent to azo bond would draw electrons from azo bond; hence the azo dye became more electrophilic and more favourable for dye reduction. Copyright © 2016 Elsevier B.V. All rights reserved.

Assimilable organic carbon (AOC) determination using GFP-tagged Pseudomonas fluorescens P-17 in water by flow cytometry.

PubMed

Tang, Peng; Wu, Jie; Liu, Hou; Liu, Youcai; Zhou, Xingding

2018-01-01

One of the newly developed methods for Assimilable organic carbon (AOC) determination is leveraged on the cell enumeration by flow cytometry (FC) which could provide a rapid and automated solution for AOC measurement. However, cell samples staining with fluorescence dye is indispensable to reduce background and machine noise. This step would bring additional cost and time consuming for this method. In this study, a green fluorescence protein (GFP) tagged strain derived of AOC testing strain Pseudomonas fluorescens P-17 (GFP-P17) was generated using Tn5 transposon mutagenesis. Continuous culture of this mutant GFP-P17 showed stable expression of eGFP signal detected by flow cytometry without staining step. In addition, this GFP-P17 strain displayed faster growth rate and had a wider range of carbon substrate utilization patterns as compared with P17 wild-type. With this strain, the capability of a new FC method with no dye staining was explored in standard acetate solution, which suggests linear correlation of counts with acetate carbon concentration. Furthermore, this FC method with GFP-P17 strain is applicable in monitoring GAC/BAC efficiency and condition as similar trends of AOC level in water treatment process were measured by both FC method and conventional spread plating count method. Therefore, this fast and easily applicable GFP-P17 based FC method could serve as a tool for routine microbiological drinking water monitoring.

The in situ generation and reactive quench of diazonium compounds in the synthesis of azo compounds in microreactors

PubMed Central

Akwi, Faith M

2016-01-01

Summary In this paper, a micro-fluidic optimized process for the continuous flow synthesis of azo compounds is presented. The continuous flow synthesis of Sudan II azo dye was used as a model reaction for the study. At found optimal azo coupling reaction temperature and pH an investigation of the optimum flow rates of the reactants for the diazotization and azo coupling reactions in Little Things Factory-MS microreactors was performed. A conversion of 98% was achieved in approximately 2.4 minutes and a small library of azo compounds was thus generated under these reaction conditions from couplers with aminated or hydroxylated aromatic systems. The scaled up synthesis of these compounds in PTFE tubing (i.d. 1.5 mm) was also investigated, where good reaction conversions ranging between 66–91% were attained. PMID:27829903

Dye-induced aggregation of single stranded RNA: a mechanistic approach.

PubMed

Biver, Tarita; Ciatto, Carlo; Secco, Fernando; Venturini, Marcella

2006-08-15

The binding of proflavine (D) to single stranded poly(A) (P) was investigated at pH 7.0 and 25 degrees C using T-jump, stopped-flow and spectrophotometric methods. Equilibrium measurements show that an external complex PD(I) and an internal complex PD(II) form upon reaction between P and D and that their concentrations depend on the polymer/dye concentration ratio (C(P)/C(D)). For C(P)/C(D)<2.5, cooperative formation of stacks external to polymer strands prevails (PD(I)). Equilibria and T-jump experiments, performed at I=0.1M and analyzed according to the Schwarz theory for cooperative binding, provide the values of site size (g=1), equilibrium constant for the nucleation step (K( *)=(1.4+/-0.6)x10(3)M(-1)), equilibrium constant for the growth step (K=(1.2+/-0.6)x10(5)M(-1)), cooperativity parameter (q=85) and rate constants for the growth step (k(r)=1.2x10(7)M(-1)s(-1), k(d)=1.1 x 10(2)s(-1)). Stopped-flow experiments, performed at low ionic strength (I=0.01 M), indicate that aggregation of stacked poly(A) strands do occur provided that C(P)/C(D)<2.5.

Determining the Discharge Rate from a Submerged Oil Leaks using ROV Video and CFD study

NASA Astrophysics Data System (ADS)

Saha, Pankaj; Shaffer, Frank; Shahnam, Mehrdad; Savas, Omer; Devites, Dave; Steffeck, Timothy

2016-11-01

The current paper reports a technique to measure the discharge rate by analyzing the video from a Remotely Operated Vehicle (ROV). The technique uses instantaneous images from ROV video to measure the velocity of visible features (turbulent eddies) along the boundary of an oil leak jet and subsequently classical theory of turbulent jets is imposed to determine the discharge rate. The Flow Rate Technical Group (FRTG) Plume Team developed this technique that manually tracked the visible features and produced the first accurate government estimates of the oil discharge rate from the Deepwater Horizon (DWH). For practical application this approach needs automated control. Experiments were conducted at UC Berkeley and OHMSETT that recorded high speed, high resolution video of submerged dye-colored water or oil jets and subsequently, measured the velocity data employing LDA and PIV software. Numerical simulation have been carried out using experimental submerged turbulent oil jets flow conditions employing LES turbulence closure and VOF interface capturing technique in OpenFOAM solver. The CFD results captured jet spreading angle and jet structures in close agreement with the experimental observations. The work was funded by NETL and DOI Bureau of Safety and Environmental Enforcement (BSEE).

Photodegradation of an azo dye of the textile industry.

PubMed

Cisneros, Rosario López; Espinoza, Abel Gutarra; Litter, Marta I

2002-07-01

An advanced oxidation treatment, UV/H2O2, was applied to an azo dye, Hispamin Black CA, widely used in the Peruvian textile industry. Rates of color removal and degradation of the dye have been evaluated. A strongly absorbing solution was completely decolorized after 35 min of treatment, and after 60 min an 82% reduction of the total organic carbon (TOC) was obtained. It has been found that the degradation rate increased until an optimum value, beyond which the reagent exerted an inhibitory effect. The degradation rate was also function of pH.

Wax Modeling and Image Analysis for Classroom-Scale Lava Flow Simulations.

NASA Astrophysics Data System (ADS)

Rader, E. L.; Clarke, A. B.; Vanderkluysen, L.

2016-12-01

The use of polyethylene glycol wax (PEG 600) as an analog for lava allows for a visual representation of the complex physical process occurring in natural lava flows, including cooling, breakouts, and crust and lobe formation. We used a series of cameras positioned around a tank filled with chilled water as a lab bench to observe and quantify lava flow morphology and motion. A peristaltic pump connected to a vent at the base of the tank delivered dyed wax simulating effusive eruptions similar to those of Kilauea in Hawai`i. By varying the eruptive conditions such as wax temperature and eruption rate, students can observe how the crust forms on wax flows, how different textures result, and how a flow field evolves with time. Recorded footage of the same `eruption' can then be quantitatively analyzed using free software like ImageJ and Tracker to quantify time-series of spreading rate, change in height, and appearance of different surface morphologies. Additional dye colors can be added periodically to further illustrate how lava is transported from the vent to the periphery of a flow field (e.g., through a tube system). Data collected from this activity can be compared to active lava flow footage from Hawai`i and with numerical models of lava flow propagation, followed by discussions of the application of these data and concepts to predicting the behavior of lava in hazard management situations and interpreting paleomagnetic, petrologic, and mapping of older eruptions.

Copper atom based measurements of velocity and turbulence in arc jet flows

NASA Technical Reports Server (NTRS)

Marinelli, William J.; Kessler, William J.; Allen, Mark G.; Arepalli, Sivaram; Scott, Carl D.

1991-01-01

Laboratory and field measurements were combined with a modeling effort to explore the feasibility of using atomic copper laser-induced fluorescence to measure velocity, turbulence, and temperature in arcjet flows. Both CW and pulsed frequency-doubled dye lasers were used to demonstrate the ability to measure velocity with 10 percent accuracy at rates of 200,000 cm/s in a rarefied flow of Cu atoms seeded in He. The pulsed laser established a threshold energy for power-broadening of the absorption line at 3.5 x 10 to the -8th J/sq cm. Field measurements at the NASA/JSC 10-MW arcjet facility demonstrated the ability to perform these measurements under actual test conditions. The use of this technique to measure freestream temperatures in the flow was examined for the 0.08/cm linewidth laser used in the NASA/JSC effort. Finally, single-shot turbulence measurements at the USAF/AEDC 35-MW H2 arcjet facility were measured with 4 percent accuracy using the laser/absorption line-overlap technique.

Detection Limits for Spectro-fluorometry: A Case Study in the Region of Finstersee, Canton Zug, Northern Switzerland

NASA Astrophysics Data System (ADS)

Otz, M. H.; Otz, H. K.; Keller, P.

2002-05-01

Synthetic fluorescent dyes, applied below the visual detection limit (< 0.1 mg/L), have been used as tracers of ground water flow paths since the beginning of the 1950s. Since 1965, we have used spectro-fluorometers with photomultipliers to measure low concentrations of fluorescent dyes in ground water in Switzerland. In collaboration with the Engineering Geology Department of the ETH, we have separated uranine at 0.1 ng/L and Na-naphtionate at 1 ng/L from background fluorescence of spring water in the Finstersee region. These values are 10-100 times lower than postulated detection limits in the literature. The use of low dye concentrations prevents a study region from being contaminated by increased background levels due to remnant dye within the aquifer, thereby leaving the region available for future dye tracing studies. Lower detection limits also can solve particular hydraulic problems where conventional methods fail and enhance the possibility for using artificial dyes in environmentally sensitive aquifer settings.

Fluorophore:dendrimer ratio impacts cellular uptake and intracellular fluorescence lifetime.

PubMed

Dougherty, Casey A; Vaidyanathan, Sriram; Orr, Bradford G; Banaszak Holl, Mark M

2015-02-18

G5-NH2-TAMRAn (n = 1-4, 5+, and 1.5(avg)) were prepared with n = 1-4 as a precise dye:dendrimer ratio, 5+ as a mixture of dendrimers with 5 or more dye per dendrimer, and 1.5(avg) as a Poisson distribution of dye:dendrimer ratios with a mean of 1.5 dye per dendrimer. The absorption intensity increased sublinearly with n whereas the fluorescence emission and lifetime decreased with an increasing number of dyes per dendrimer. Flow cytometry was employed to quantify uptake into HEK293A cells. Dendrimers with 2-4 dyes were found to have greater uptake than dendrimer with a single dye. Fluorescence lifetime imaging microscopy (FLIM) showed that the different dye:dendrimer ratio alone was sufficient to change the fluorescence lifetime of the material observed inside cells. We also observed that the lifetime of G5-NH2-TAMRA5+ increased when present in the cell as compared to solution. However, cells treated with G5-NH2-TAMRA1.5(avg) did not exhibit the high lifetime components present in G5-NH2-TAMRA1 and G5-NH2-TAMRA5+. In general, the effects of the dye:dendrimer ratio on fluorescence lifetime were of similar magnitude to environmentally induced lifetime shifts.

Measurement of atmospheric OH by titration of near-IR fluorescent dyes

NASA Technical Reports Server (NTRS)

Betterton, Eric A.; Gast, Karl

1994-01-01

Recent research has shown that certain polymethine dyes can be detected at ultratrace levels (greater than or equal to 6x10(exp -14) M) in solution by fluorimetry. These detection limits are possible because of the inherent sensitivity of fluorescence techniques, because the dyes fluoresce in the near infrared region where background interference is negligible, and because powerful infrared diode lasers are now available to improve the signal to noise ratio. Other work has shown that the hydroxyl radical destroys the ability of polymethine dyes to fluoresce. These observations form the basis for a new hydroxyl radical detector that is essentially a fluorometric titrator. Theoretically, the detector should show an acceptable sensitivity and response time. Assuming that the atmospheric HO concentration is about 10(exp -11) moles m(exp -3) (i.e. 10(exp 6) molecules cm(exp -3)), then 10 L of air 'titrated' with 20 mL of 10(exp -11) M dye solution (an easily detected concentration) should result in a drop in the fluorescent signal of 50 percent - a readily detectable change. At a flow rate of 3 L min(exp -1) the sampling time would be 3 minutes. The biggest potential problem is selectivity: other oxidants may also cause the fluorescence signal to be lost. The chemistry of polymethine dyes has not been studied in detail and so no quantitative data are available. However, a survey of the literature suggests that in general HO should react up to six orders of magnitude faster than HO2 and other radicals such as RO2 and RO. It should also react much more rapidly than H2O2 and O3. Thus it may be possible to discriminate kinetically against potential interfering substances. It was shown in the laboratory that 10(exp -4) M H2O2 has little effect on the absorption spectrum of the dye IR125 over a period of hours but that the band at 780 nm is slowly lost in water over a period of days even under argon in the dark. By contrast, DMSO solutions of IR125 are stable.

Photocatalytic degradation of organic dyes using composite nanofibers under UV irradiation

NASA Astrophysics Data System (ADS)

Salama, Ahmed; Mohamed, Alaa; Aboamera, Nada M.; Osman, T. A.; Khattab, A.

2018-02-01

In this work, photocatalytic degradation of organic dyes such as methylene blue (MB) and indigo carmine (IC) have been studied by composite nanofibers systems containing cellulose acetate (CA), multiwall carbon nanotubes (CNT) and TiO2 nanoparticles under UV light. The amino factionalized TiO2-NH2 NPs cross-linked to the CA/CNT composite nanofibers works as a semiconductor catalyst. The morphology and crystallinity were characterized by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, and Fourier transform infrared spectroscopy. It was also seen that many factors affected the photodegradation rate, mainly the pH of the solution and the dye concentration, temperature, etc. The study demonstrated that IC degrades at a higher rate than MB. The maximum photodegradation rate of both organic dyes was achieved at a pH 2. In comparison to other studies, this work achieved high photodegradation rate in lower time and using less power intensity.

Photocatalytic degradation of Maxilon C.I. basic dye using CS/CoFe2O4/GONCs as a heterogeneous photo-Fenton catalyst prepared by gamma irradiation.

PubMed

Al-Kahtani, Abdullah A; Abou Taleb, Manal F

2016-05-15

CS/CF/GONCs were synthesized via gamma irradiation cross-linking method with the aid of sonication. The nanocomposites exhibited a photo-Fenton catalytic feature for the degradation of Maxilon C.I. basic dye in aqueous medium using sunlight. The effects of pH, H2O2 concentration, and dosage of the catalyst, on the degradation rates of the dyes were examined. The optimal degradation rate was reached with 10mM H2O2 at pH 9.5. It was verified that the Maxilon C.I. basic dye degradation rate fits a pseudo-first-order kinetics for different initial concentrations of Maxilon C.I. dye. Fourth cyclic tests for Maxilon C.I. degradation showed that the magnetic catalyst was very stable, recoverable, highly active, and easy to separate using an external magnet. Hence, this magnetic catalyst has potential use in organic pollutant removal. Copyright © 2016 Elsevier B.V. All rights reserved.

A Hand-held Fiber-optic Implement for the Site-specific Delivery of Photosensitizer and Singlet Oxygen

PubMed Central

Mahendran, Adaickapillai; Kopkalli, Yasemin; Ghosh, Goutam; Ghogare, Ashwini; Minnis, Mihaela; Kruft, Bonnie I.; Zamadar, Matibur; Aebisher, David; Davenport, Lesley; Greer, Alexander

2012-01-01

We have constructed a fiber optic device that internally flows triplet oxygen and externally produces singlet oxygen, causing a reaction at the (Z)-1,2-dialkoxyethene spacer group, freeing a pheophorbide sensitizer upon the fragmentation of a reactive dioxetane intermediate. The device can be operated and sensitizer photorelease observed using absorption and fluorescence spectroscopy. We demonstrate the preference of sensitizer photorelease when the probe tip is in contact with octanol or lipophilic media. A first-order photocleavage rate constant of 1.13 h−1 was measured in octanol where dye desorption was not accompanied by readsorption. When the probe tip contacts aqueous solution, the photorelease was inefficient because most of the dye adsorbed on the probe tip, even after the covalent ethene spacer bonds have been broken. The observed stability of the free sensitizer in lipophilic media is reasonable even though it is a pyropheophorbide-a derivative that carries a p-formylbenzylic alcohol substituent at the carboxylic acid group. In octanol or lipid systems, we found that the dye was not susceptible to hydrolysis to pyropheophorbide-a, otherwise a pH effect was observed in a binary methanol-water system (9:1) at pH below 2 or above 8. PMID:21790616

Assessing flow paths in a karst aquifer based on multiple dye tracing tests using stochastic simulation and the MODFLOW-CFP code

NASA Astrophysics Data System (ADS)

Assari, Amin; Mohammadi, Zargham

2017-09-01

Karst systems show high spatial variability of hydraulic parameters over small distances and this makes their modeling a difficult task with several uncertainties. Interconnections of fractures have a major role on the transport of groundwater, but many of the stochastic methods in use do not have the capability to reproduce these complex structures. A methodology is presented for the quantification of tortuosity using the single normal equation simulation (SNESIM) algorithm and a groundwater flow model. A training image was produced based on the statistical parameters of fractures and then used in the simulation process. The SNESIM algorithm was used to generate 75 realizations of the four classes of fractures in a karst aquifer in Iran. The results from six dye tracing tests were used to assign hydraulic conductivity values to each class of fractures. In the next step, the MODFLOW-CFP and MODPATH codes were consecutively implemented to compute the groundwater flow paths. The 9,000 flow paths obtained from the MODPATH code were further analyzed to calculate the tortuosity factor. Finally, the hydraulic conductivity values calculated from the dye tracing experiments were refined using the actual flow paths of groundwater. The key outcomes of this research are: (1) a methodology for the quantification of tortuosity; (2) hydraulic conductivities, that are incorrectly estimated (biased low) with empirical equations that assume Darcian (laminar) flow with parallel rather than tortuous streamlines; and (3) an understanding of the scale-dependence and non-normal distributions of tortuosity.

A diffusion based long-range and steady chemical gradient generator on a microfluidic device for studying bacterial chemotaxis

NASA Astrophysics Data System (ADS)

Murugesan, Nithya; Singha, Siddhartha; Panda, Tapobrata; Das, Sarit K.

2016-03-01

Studies on chemotaxis in microfluidics device have become a major area of research to generate physiologically similar environment in vitro. In this work, a novel micro-fluidic device has been developed to study chemo-taxis of cells in near physiological condition which can create controllable, steady and long-range chemical gradients using various chemo-effectors in a micro-channel. Hydrogels like agarose, collagen, etc, can be used in the device to maintain exclusive diffusive flux of various chemical species into the micro-channel under study. Variations of concentrations and flow rates of Texas Red dextran in the device revealed that an increase in the concentration of the dye in the feed from 6 to 18 μg ml-1, causes a steeper chemical gradient in the device, whereas the flow rate of the dye has practically no effect on the chemical gradient in the device. This observation confirms that a diffusion controlled chemical gradient is generated in the micro-channel. Chemo-taxis of E. coli cells were studied under the steady gradient of a chemo-attractant and a chemo-repellent separately in the same chemical gradient generator. For sorbitol and NiSO4·6H2O, the bacterial cells exhibit a steady distribution in the micro channel after 1 h and 30 min, respectively. From the distribution of bacterial population chemo-tactic strength of the chemo-effectors was estimated for E. coli. In a long microfluidic channel, migration behavior of bacterial cells under diffusion controlled chemical gradient showed chemotaxis, random movement, aggregation, and concentration dependent reverse chemotaxis.

Is blue dye still required during sentinel lymph node biopsy for breast cancer?

PubMed

Peek, Mirjam Cl; Kovacs, Tibor; Baker, Rose; Hamed, Hisham; Kothari, Ash; Douek, Michael

2016-01-01

In early breast cancer, the optimal technique for sentinel lymph node biopsy (SLNB) is the combined technique (radioisotope and Patent Blue V) which achieves high identification rates. Despite this, many centres have decided to stop using blue dye due to blue-dye-related complications (tattoo, anaphylaxis). We evaluated the SLNB identification rate using the combined technique with and without Patent Blue V and the blue-dye-related complication rates. Clinical and histological data were analysed on patients undergoing SLNB between March 2014 and April 2015. SLNB was performed following standard hospital protocols using the combined technique. A total of 208 patients underwent SLNB and 160 patients (342 nodes) with complete operation notes were available for final analysis. The identification rate with the combined technique was 98.8% ( n = 158/160), with blue dye alone 92.5% ( n = 148/160) and with radioisotope alone 97.5% ( n = 156/160). A total of 76.9% (263/342) of nodes were radioactive and blue, 15.5% (53/342) only radioactive and 2.3% (8/342) only blue, 5.3% (18/342) were neither radioactive nor blue. No anaphylactic reactions were reported and blue skin staining was reported in six (3.8%) patients. The combined technique should continue be the preferred technique for SLNB and should be standardised. Radioisotope alone (but not blue dye alone) has comparable sentinel node identification rates in experienced hands. National guidelines are required to optimise operative documentation.

Raman Enhancement and Photo-Bleaching of Organic Dyes in the Presence of Chemical Vapor Deposition-Grown Graphene.

PubMed

Weng, Jiaxin; Zhao, Shichao; Li, Zhiting; Ricardo, Karen B; Zhou, Feng; Kim, Hyojeong; Liu, Haitao

2017-10-19

Fluorescent organic dyes photobleach under intense light. Graphene has been shown to improve the photo-stability of organic dyes. In this paper, we investigated the Raman spectroscopy and photo-bleaching kinetics of dyes in the absence/presence of chemical vapor deposition (CVD)-grown graphene. We show that graphene enhances the Raman signal of a wide range of dyes. The photo-bleaching of the dyes was reduced when the dyes were in contact with graphene. In contrast, monolayer hexagonal boron nitride (h-BN) was much less effective in reducing the photo-bleaching rate of the dyes. We attribute the suppression of photo-bleaching to the energy or electron transfer from dye to graphene. The results highlight the potential of CVD graphene as a substrate for protecting and enhancing Raman response of organic dyes.

Time-of-travel data for Nebraska streams, 1968 to 1977

USGS Publications Warehouse

Petri, L.R.

1984-01-01

This report documents the results of 10 time-of-travel studies, using ' dye-tracer ' methods, conducted on five streams in Nebraska during the period 1968 to 1977. Streams involved in the studies were the North Platte, North Loup, Elkhorn, and Big Blue Rivers and Salt Creek. Rhodamine WT dye in a 20 percent solution was used as the tracer for all 10 time-of-travel studies. Water samples were collected at several points below each injection site. Concentrations of dye in the samples were measured by determining fluorescence of the sample and comparing that value to fluorescence-concentration curves. Stream discharges were measured before and during each study. Results of each time-by-travel study are shown on two tables and on graph. The first table shows water discharge at injection and sampling sites, distance between sites, and time and rate of travel of the dye between sites. The second table provides descriptions of study sites, amounts of dye injected in the streams, actual sampling times, and actual concentrations of dye detected. The graphs for each time-of-travel study provide indications of changing travel rates between sampling sites, information on length of dye clouds, and times for dye passage past given points. (USGS)

Optimization of photocatalytic degradation of sulphonated diazo dye C.I. Reactive Green 19 using ceramic-coated TiO2 nanoparticles.

PubMed

Rastegar, M; Shadbad, K Rahmati; Khataee, A R; Pourrajab, R

2012-01-01

Optimization of photocatalytic degradation of C.I. Reactive Green 19 (RG 19) under UV light irradiation using ceramic-coated TiO2 nanoparticles in a continuous circulation rectangular photoreactor was studied. The used catalyst was TiO2 Millennium PC-500 (crystallite mean size 8 nm) immobilized on ceramic plates. A central composite design was used for optimization of the UV/TiO2 process. Predicted values of decolorization efficiency were found to be in good agreement with experimental values (R2 = 0.97 and Adj-R2 = 0.91). Optimization results showed that maximum decolorization efficiency was achieved at the optimum conditions of: initial dye concentration 10 mg/L, UV light intensity 47.2 W/m2, flow rate 150 mL/min and reaction time 240 min. Photocatalytic mineralization of RG 19 was monitored by chemical oxygen demand (COD) decrease and changes in the UV-Vis spectrum.

Decolorization and degradation of reactive yellow HF aqueous solutions by electrochemical advanced oxidation processes.

PubMed

Bedolla-Guzman, A; Feria-Reyes, R; Gutierrez-Granados, S; Peralta-Hernández, Juan M

2017-05-01

Textile manufacturing is the one responsible for water bodies' contamination through the discharge of colored wastes. This work presents the study of reactive yellow HF (RYHF) dye degradation under two different electrochemical advanced oxidation processes (EAOP), namely anodic oxidation (AO) and electro-Fenton (EF)/boron-doped diamond (BDD) process. For the AO, 100 and 300 mg/L solutions using Pt and BDD as anodes in a 100 mL stirred tank cell were used, with a supporting electrolyte of 0.05 mol/L of Na 2 SO 4 at pH 3 under 30 and 50 mA/cm 2 current density. The EF/BDD process was carried out in a flow reactor at 4 and 7 L/min to degrade 100, 200, and 300 mg/L RYHF solutions under 50 and 80 mA/cm 2 . UV-Vis determinations were used for decolorization evaluation, while high-performance liquid chromatography (HPLC) method provided information on dye degradation rate.

Electron beam treatment of textile dyeing wastewater: operation of pilot plant and industrial plant construction.

PubMed

Han, B; Kim, J; Kim, Y; Choi, J S; Makarov, I E; Ponomarev, A V

2005-01-01

A pilot plant for treating 1000 m3/day of dyeing wastewater with e-beam has been constructed and operated since 1998 in Daegu, Korea together with the biological treatment facility. The wastewater from various stages of the existing purification process has been treated with an electron beam in this plant, and it gave rise to elaborating the optimal technology of the electron beam treatment of wastewater with increased reliability for instant changes in the composition of wastewater. Installation of the e-beam pilot plant resulted in decolorizing and destructive oxidation of organic impurities in wastewater, appreciable reduction of chemical reagent consumption, in reduction of the treatment time, and in increase in the flow rate limit of existing facilities by 30-40%. Industrial plant for treating 10,000 m3/day each, based upon the pilot experimental result, is under construction and will be finished by 2005. This project is supported by the International Atomic Energy Agency (IAEA) and Korean Government.

Influence of aromatic substitution patterns on azo dye degradability by Streptomyces spp. and Phanerochaete chrysosporium.

PubMed Central

Pasti-Grigsby, M B; Paszczynski, A; Goszczynski, S; Crawford, D L; Crawford, R L

1992-01-01

Twenty-two azo dyes were used to study the influence of substituents on azo dye biodegradability and to explore the possibility of enhancing the biodegradabilities of azo dyes without affecting their properties as dyes by changing their chemical structures. Streptomyces spp. and Phanerochaete chrysosporium were used in the study. None of the actinomycetes (Streptomyces rochei A10, Streptomyces chromofuscus A11, Streptomyces diastaticus A12, S. diastaticus A13, and S. rochei A14) degraded the commercially available Acid Yellow 9. Decolorization of monosulfonated mono azo dye derivatives of azobenzene by the Streptomyces spp. was observed with five azo dyes having the common structural pattern of a hydroxy group in the para position relative to the azo linkage and at least one methoxy and/or one alkyl group in an ortho position relative to the hydroxy group. The fungus P. chrysosporium attacked Acid Yellow 9 to some extent and extensively decolorized several azo dyes. A different pattern was seen for three mono azo dye derivatives of naphthol. Streptomyces spp. decolorized Orange I but not Acid Orange 12 or Orange II. P. chrysosporium, though able to transform these three azo dyes, decolorized Acid Orange 12 and Orange II more effectively than Orange I. A correlation was observed between the rate of decolorization of dyes by Streptomyces spp. and the rate of oxidative decolorization of dyes by a commercial preparation of horseradish peroxidase type II, extracellular peroxidase preparations of S. chromofuscus A11, or Mn(II) peroxidase from P. chrysosporium. Ligninase of P. chrysosporium showed a dye specificity different from that of the other oxidative enzymes.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1482183

Impact of Indocyanine Green for Sentinel Lymph Node Mapping in Early Stage Endometrial and Cervical Cancer: Comparison with Conventional Radiotracer (99m)Tc and/or Blue Dye.

PubMed

Buda, Alessandro; Crivellaro, Cinzia; Elisei, Federica; Di Martino, Giampaolo; Guerra, Luca; De Ponti, Elena; Cuzzocrea, Marco; Giuliani, Daniela; Sina, Federica; Magni, Sonia; Landoni, Claudio; Milani, Rodolfo

2016-07-01

To compare the detection rate (DR) and bilateral optimal mapping (OM) of sentinel lymph nodes (SLNs) in women with endometrial and cervical cancer using indocyanine green (ICG) versus the standard technetium-99m radiocolloid ((99m)Tc) radiotracer plus methylene or isosulfan blue, or blue dye alone. From October 2010 to May 2015, 163 women with stage I endometrial or cervical cancer (118 endometrial and 45 cervical cancer) underwent SLN mapping with (99m)Tc with blue dye, blue dye alone, or ICG. DR and bilateral OM of ICG were compared respectively with the results obtained using the standard (99m)Tc radiotracer with blue dye, or blue dye alone. SLN mapping with (99m)Tc radiotracer with blue dye was performed on 77 of 163 women, 38 with blue dye only and 48 with ICG. The overall DR of SLN mapping was 97, 89, and 100 % for (99m)Tc with blue dye, blue dye alone, and ICG, respectively. The bilateral OM rate for ICG was 85 %-significantly higher than the 58 % obtained with (99m)Tc with blue dye (p = 0.003) and the 54 % for blue dye (p = 0.001). Thirty-one women (19 %) had positive SLNs. Sensitivity and negative predictive value of SLN were 100 % for all techniques. SLNs mapping using ICG demonstrated higher DR compared to other modalities. In addition, ICG was significantly superior to (99m)Tc with blue dye in terms of bilateral OM in women with early stage endometrial and cervical cancer. The higher number of bilateral OM may consequently reduce the overall number of complete lymphadenectomies, reducing the duration and additional costs of surgical treatment.

Catalytic reduction of organic dyes at gold nanoparticles impregnated silica materials: influence of functional groups and surfactants

NASA Astrophysics Data System (ADS)

Azad, Uday Pratap; Ganesan, Vellaichamy; Pal, Manas

2011-09-01

Gold nanoparticles (Au NPs) in three different silica based sol-gel matrixes with and without surfactants are prepared. They are characterized by UV-vis absorbance and transmission electron microscopic (TEM) studies. The size and shape of Au NPs varied with the organo-functional group present in the sol-gel matrix. In the presence of mercaptopropyl functionalized organo-silica, large sized (200-280 nm) spherical Au NPs are formed whereas in the presence of aminopropyl functionalized organo-silica small sized (5-15 nm) Au NPs are formed inside the tube like organo-silica. Further, it is found that Au NPs act as efficient catalyst for the reduction of organic dyes. The catalytic rate constant is evaluated from the decrease in absorbance of the dye molecules. Presence of cationic or anionic surfactants greatly influences the catalytic reaction. The other factors like hydrophobicity of the organic dyes, complex formation of the dyes with anionic surfactants, repulsion between dyes and cationic surfactant, adsorption of dyes on the Au NPs also play important role on the reaction rate.

On the flow through the normal fetal aortic arc at late gestation

NASA Astrophysics Data System (ADS)

Pekkan, Kerem; Nourparvar, Paymon; Yerneni, Srinivasu; Dasi, Lakshmi; de Zelicourt, Diane; Fogel, Mark; Yoganathan, Ajit

2006-11-01

During the fetal stage, the aortic arc is a complex junction of great vessels (right and left ventricular outflow tracks (RVOT, LVOT), pulmonary arteries (PA), ductus, head-neck vessels, decending aorta (Dao)) delicately distributing the oxygenated blood flow to the lungs and the body -preferential to the brain. Experimental and computational studies are performed in idealized models of the fetal aorta to understand and visualize the unsteady hemodynamics. Unsteady in vitro flow, generated by two peristaltic pumps (RVOT and LVOT) is visualized with two colored dyes and a red laser in a rigid glass model with physiological diameters. Helical flow patterns at the PA's and ductal shunting to the Dao are visualized. Computational fluid dynamics of the same geometry is modeled using the commercial code Fidap with porous boundary conditions representing systemic and pulmonary resistances (˜400000 tetrahedral elements). Combined (RVOT+LVOT) average flow rates ranging from 1.9 to 2.1-L/min for 34 to 38-weeks gestation were simulated with the Reynolds and Womersly numbers (Dao) of 500 and 8. Computational results are compared qualitatively with the flow visualizations at this target flow condition. Understanding fetal hemodynamics is critical for congenital heart defects, tissue engineering, fetal cardiac MRI and surgeries.

Visualizing Vector Fields Using Line Integral Convolution and Dye Advection

NASA Technical Reports Server (NTRS)

Shen, Han-Wei; Johnson, Christopher R.; Ma, Kwan-Liu

1996-01-01

We present local and global techniques to visualize three-dimensional vector field data. Using the Line Integral Convolution (LIC) method to image the global vector field, our new algorithm allows the user to introduce colored 'dye' into the vector field to highlight local flow features. A fast algorithm is proposed that quickly recomputes the dyed LIC images. In addition, we introduce volume rendering methods that can map the LIC texture on any contour surface and/or translucent region defined by additional scalar quantities, and can follow the advection of colored dye throughout the volume.

Visualizing dissolved oxygen transport for liquid ventilation in an in vitro model of the human airways

NASA Astrophysics Data System (ADS)

Janke, T.; Bauer, K.

2017-04-01

Up until to now, the measurement of dissolved oxygen concentrations during liquid ventilation is limited to the determination of averaged concentrations of the liquid entering or leaving the body. The work presented in this paper aims to extend the possible measurement techniques in the research of liquid ventilation. Therefore optical measurements of the dissolved oxygen concentration, using a luminescent sensor dye, are performed. The preparation of a suitable sensor liquid, based on the metal complex Dichlorotris(1,10)-(phenanthroline)ruthenium(II), is presented. A transparent simplified human lung geometry is used for conducting the experiments. Inspiratory as well as expiratory flow at three different constant flow rates is investigated, covering the flow regimes \\text{Re}=83 -333 and \\text{Pe}=33 300 -133 000. The applied measurement technique is capable to reveal distinctive concentration patterns during inspiration and expiration caused by the laminar flow characteristics. Allowing a sufficiently long flow duration, local concentration inhomogeneities disappear and an exponential rise and decay of the mean values can be observed for inspiration and expiration.

Effect of simulated hyperemia on the flow field in a mildly atherosclerotic coronary artery casting of man

NASA Technical Reports Server (NTRS)

Cho, Y. I.; Back, L. H.; Crawford, D. W.

1985-01-01

Changes in an arterial flow field due to mild atherosclerosis were determined using a main coronary artery casting with a maximum obstruction of about 50 percent by area. Local pressure changes were measured using six pressure tap holes along the wall of the casting. The test-fluid was a 33 percent sugar-water solution of approximately the same viscosity as human blood. Flow visualization results were obtained by injecting blue-dye through the pressure tap holes. Measurement of local pressure demonstrated a significant Reynolds number effect. At Reynolds numbers of 80-710, a local pressure rise was observed downstream of the mild atherosclerotic constriction due to momentum changes. The Reynolds number necessary for flow separation in the divergent region of the coronary casting was about 330. The experimental results can be used to obtain a quantitative relation between coronary morphology and the fluid dynamic consequences of mild diffuse disease under conditions of maximum cardiac demand i.e., higher coronary flow rates and Reynolds numbers associated with space and atmospheric flight.

Overhead Projection Cell for Streamline Flow

ERIC Educational Resources Information Center

Waage, Harold M.

1969-01-01

Describes the construction and operation of an overhead projection apparatus designed to demonstrate streamline flow of a liquid. The apparatus consists of a Plexiglass tank containing water in which plates forming the cell are submerged, a constant level reservoir, an overflow device and a system for marking the flow lines with a dye. (LC)

A Process Dynamics and Control Experiment for the Undergraduate Laboratory

ERIC Educational Resources Information Center

Spencer, Jordan L.

2009-01-01

This paper describes a process control experiment. The apparatus includes a three-vessel glass flow system with a variable flow configuration, means for feeding dye solution controlled by a stepper-motor driven valve, and a flow spectrophotometer. Students use impulse response data and nonlinear regression to estimate three parameters of a model…

Formic acid enhanced effective degradation of methyl orange dye in aqueous solutions under UV-Vis irradiation.

PubMed

Wang, Jingjing; Bai, Renbi

2016-09-15

Developing efficient technologies to treat recalcitrant organic dye wastewater has long been of great research and practical interest. In this study, a small molecule, formic acid (FA), was applied as a process enhancer for the degradation of methyl orange (MO) dye as a model recalcitrant organic pollutant in aqueous solutions under the condition of UV-Vis light irradiation and air aeration at the ambient temperature of 25 °C. It was found that the decolouration of the dye solutions can be rapidly achieved, reducing the time, for example, from around 17.6 h without FA to mostly about less than 2 h with the presence of FA. The mineralization rate of MO dye reached as high as 81.8% in 1.5 h in the case of initial MO dye concentration at 25 mg L(-1), which is in contrast to nearly no mineralization of the MO dye for a similar system without the FA added. The study revealed that the generation of the H2O2 species in the system was enhanced and the produced OH radicals effectively contributed to the degradation of the MO dye. Process parameters such as the initial concentration of MO dye, FA dosage and solution pH were all found to have some effect on the degradation efficiency under the same condition of UV-Vis light irradiation and air aeration. The MO dye degradation performance was found to follow a first-order reaction rate to the MO dye concentration in most cases and there existed a positive correlation between the reaction rate constant and the initial FA concentration. Compared to the traditional H2O2/UV-Vis oxidation system, the use of FA as a process-enhancing agent can have the advantages of low cost, easy availability, and safe to use. The study hence demonstrates a promising approach to use a readily available small molecule of FA to enhance the degradation of recalcitrant organic pollutants, such as MO dye, especially for their pre-treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rapid Dye Regeneration Mechanism of Dye-Sensitized Solar Cells.

PubMed

Jeon, Jiwon; Park, Young Choon; Han, Sang Soo; Goddard, William A; Lee, Yoon Sup; Kim, Hyungjun

2014-12-18

During the light-harvesting process of dye-sensitized solar cells (DSSCs), the hole localized on the dye after the charge separation yields an oxidized dye, D(+). The fast regeneration of D(+) using the redox pair (typically the I(-)/I3(-) couple) is critical for the efficient DSSCs. However, the kinetic processes of dye regeneration remain uncertain, still promoting vigorous debates. Here, we use molecular dynamics simulations to determine that the inner-sphere electron-transfer pathway provides a rapid dye regeneration route of ∼4 ps, where penetration of I(-) next to D(+) enables an immediate electron transfer, forming a kinetic barrier. This explains the recently reported ultrafast dye regeneration rate of a few picoseconds determined experimentally. We expect that our MD based comprehensive understanding of the dye regeneration mechanism will provide a helpful guideline in designing TiO2-dye-electrolyte interfacial systems for better performing DSSCs.

Study of the sonophotocatalytic degradation of basic blue 9 industrial textile dye over slurry titanium dioxide and influencing factors.

PubMed

González, Antonia Sandoval; Martínez, Susana Silva

2008-09-01

The sonophotocatalytic degradation of basic blue 9 industrial textile dye has been studied in the presence of ultrasound (20 kHz) over a TiO(2) slurry employing an UV lamp (15 W, 352 nm). It was observed that the color removal efficiency was influenced by the pH of the solution, initial dye concentration and TiO(2) amount. It was found that the dye degradation followed apparent first order kinetics. The rate constant increased by decreasing dye concentration and was affected by the pH of the solution with the highest degradation obtained at pH 7. The first order rate constants obtained with sonophotocatalysis were twofold and tenfold than those obtained under photocatalysis and sonolysis, respectively. The chemical oxygen demand was abated over 80%.

Surface activity of branched alkylamino-compounds and their influence on phase transfer behavior in water solutions of dyes

NASA Astrophysics Data System (ADS)

Li, Cuiqin; Guo, Suyue; Lin, Zhiyu; Wang, Jun; Ge, Tengjie

2016-02-01

Two branched alkylamino-compounds (AAC, R12-0.5G, and R12-1.0G), were synthesized from dodecylamine, methyl acrylate and ethylenediamine. The surface tension measurements on branched alkylamino- compounds demonstrated that surface activity of R12-1.0G is superior to that of R12-0.5G at 25°C. It has been found that the self-assembly of R12-1.0G and lauric acid formed by electrostatic interaction and the self-assembly of the molecule might transfer water-soluble dyes from water to toluene. These AAC might be applied for treating dyes in wastewater. The mass ratio of lauric to toluene, the concentration of R12-1.0G, and hydrophilic groups of dyes affected the transfer rate of the water-soluble dyes. The transfer rates of the watersoluble dyes by R12-1.0G were higher than that of 1.0G polyacrylamide-acrylamide.

Evaluation between ultrahigh pressure liquid chromatography and high-performance liquid chromatography analytical methods for characterizing natural dyestuffs.

PubMed

Serrano, Ana; van Bommel, Maarten; Hallett, Jessica

2013-11-29

An evaluation was undertaken of ultrahigh pressure liquid chromatography (UHPLC) in comparison to high-performance liquid chromatography (HPLC) for characterizing natural dyes in cultural heritage objects. A new UHPLC method was optimized by testing several analytical parameters adapted from prior UHPLC studies developed in diverse fields of research. Different gradient elution programs were tested on seven UHPLC columns with different dimensions and stationary phase compositions by applying several mobile phases, flow rates, temperatures, and runtimes. The UHPLC method successfully provided more improved data than that achieved by the HPLC method. Indeed, even though carminic acid has shown circa 146% higher resolution with HPLC, UHPLC resulted in an increase of 41-61% resolution and a decrease of 91-422% limit of detection, depending on the dye compound. The optimized method was subsequently assigned to analyse 59 natural reference materials, in which 85 different components were ascribed with different physicochemical properties, in order to create a spectral database for future characterization of dyes in cultural heritage objects. The majority of these reference samples could be successfully distinguished with one single method through the examination of these compounds' retention times and their spectra acquired with a photodiode array detector. These results demonstrate that UHPLC analyses are extremely valuable for the acquisition of more precise chromatographic information concerning natural dyes with complex mixtures of different and/or closely related physicochemical properties, essential for distinguishing similar species of plants and animals used to colour cultural heritage objects. Copyright © 2013 Elsevier B.V. All rights reserved.

Mapping of cavitational activity in a pilot plant dyeing equipment.

PubMed

Actis Grande, G; Giansetti, M; Pezzin, A; Rovero, G; Sicardi, S

2015-11-01

A large number of papers of the literature quote dyeing intensification based on the application of ultrasound (US) in the dyeing liquor. Mass transfer mechanisms are described and quantified, nevertheless these experimental results in general refer to small laboratory apparatuses with a capacity of a few hundred millilitres and extremely high volumetric energy intensity. With the strategy of overcoming the scale-up inaccuracy consequent to the technological application of ultrasounds, a dyeing pilot-plant prototype of suitable liquor capacity (about 40 L) and properly simulating several liquor to textile hydraulic relationships was designed by including US transducers with different geometries. Optimal dyeing may be obtained by optimising the distance between transducer and textile material, the liquid height being a non-negligible operating parameter. Hence, mapping the cavitation energy in the machinery is expected to provide basic data on the intensity and distribution of the ultrasonic field in the aqueous liquor. A flat ultrasonic transducer (absorbed electrical power of 600 W), equipped with eight devices emitting at 25 kHz, was mounted horizontally at the equipment bottom. Considering industrial scale dyeing, liquor and textile substrate are reciprocally displaced to achieve a uniform colouration. In this technology a non uniform US field could affect the dyeing evenness to a large extent; hence, mapping the cavitation energy distribution in the machinery is expected to provide fundamental data and define optimal operating conditions. Local values of the cavitation intensity were recorded by using a carefully calibrated Ultrasonic Energy Meter, which is able to measure the power per unit surface generated by the cavitation implosion of bubbles. More than 200 measurements were recorded to define the map at each horizontal plane positioned at a different distance from the US transducer; tap water was heated at the same temperature used for dyeing tests (60°C). Different liquid flow rates were tested to investigate the effect of the hydrodynamics characterising the equipment. The mapping of the cavitation intensity in the pilot-plant machinery was performed to achieve with the following goals: (a) to evaluate the influence of turbulence on the cavitation intensity, and (b) to determine the optimal distance from the ultrasound device at which a fabric should be positioned, this parameter being a compromise between the cavitation intensity (higher next to the transducer) and the US field uniformity (achieved at some distance from this device). By carrying out dyeing tests of wool fabrics in the prototype unit, consistent results were confirmed by comparison with the mapping of cavitation intensity. Copyright © 2015 Elsevier B.V. All rights reserved.

Biphasic reduction model for predicting the impacts of dye-bath constituents on the reduction of tris-azo dye Direct Green-1 by zero valent iron (Fe0).

PubMed

Kumar, Raja; Sinha, Alok

2017-02-01

Influence of common dye-bath additives, namely sodium chloride, ammonium sulphate, urea, acetic acid and citric acid, on the reductive decolouration of Direct Green 1 dye in the presence of Fe 0 was investigated. Organic acids improved dye reduction by augmenting Fe 0 corrosion, with acetic acid performing better than citric acid. NaCl enhanced the reduction rate by its 'salting out' effect on the bulk solution and by Cl - anion-mediated pitting corrosion of iron surface. (NH 4 ) 2 SO 4 induced 'salting out' effect accompanied by enhanced iron corrosion by SO 4 2- anion and buffering effect of NH 4 + improved the reduction rates. However, at 2g/L (NH 4 ) 2 SO 4 concentration, complexating of SO 4 2- with iron oxides decreased Fe 0 reactivity. Urea severely compromised the reduction reaction, onus to its chaotropic and 'salting in' effect in solution, and due to it masking the Fe 0 surface. Decolouration obeyed biphasic reduction kinetics (R 2 >0.993 in all the cases) exhibiting an initial rapid phase, when more than 95% dye reduction was observed, preceding a tedious phase. Maximum rapid phase reduction rate of 0.955/min was observed at pH2 in the co-presence of all dye-bath constituents. The developed biphasic model reckoned the influence of each dye-bath additive on decolouration and simulated well with the experimental data obtained at pH2. Copyright © 2016. Published by Elsevier B.V.

High Temperature Aquifer Storage

NASA Astrophysics Data System (ADS)

Ueckert, Martina; Niessner, Reinhard; Baumann, Thomas

2016-04-01

Combined heat and power generation (CHP) is highly efficient because excess heat is used for heating and/or process energy. However, the demand of heat energy varies considerably throughout the year while the demand for electrical energy is rather constant. It seems economically and ecologically highly beneficial for municipalities and large power consumers such as manufacturing plants to store excess heat in groundwater aquifers and to recuperate this energy at times of higher demand. Within the project High Temperature Aquifer Storage, scientists investigate storage and recuperation of excess heat energy into the bavarian Malm aquifer. Apart from high transmissivity and favorable pressure gradients, the hydrochemical conditions are crucial for long-term operation. An enormous technical challenge is the disruption of the carbonate equilibrium - modeling results indicated a carbonate precipitation of 10 - 50 kg/d in the heat exchangers. The test included five injection pulses of hot water (60 °C up to 110 °C) and four tracer pulses, each consisting of a reactive and a conservative fluorescent dye, into a depth of about 300 m b.s.l. resp. 470 m b.s.l. Injection and production rates were 15 L/s. To achieve the desired water temperatures, about 4 TJ of heat energy were necessary. Electrical conductivity, pH and temperature were recorded at a bypass where also samples were taken. A laboratory container at the drilling site was equipped for analysing the concentration of the dyes and the major cations at sampling intervals of down to 15 minutes. Additional water samples were taken and analysed in the laboratory. The disassembled heat exchanger prooved that precipitation was successfully prevented by adding CO2 to the water before heating. Nevertheless, hydrochemical data proved both, dissolution and precipitation processes in the aquifer. This was also suggested by the hydrochemical modelling with PhreeqC and is traced back to mixture dissolution and changing temperatures. Optimising the addition of CO2 might help to reduce hydrochemical processes in the aquifer. As a side effect of the extremely good hydraulic conditions, the research well was flowing freely with up to 19.4 L/s which resulted in a significant mixing of the injected water with formation waters during production. Due to the hydrochemical contrast of the sodium concentration, quantification of inflowing reservoir water was possible. Therefore, prognosis of the temperature development during the operation with flow rates of up to 60 L/s can be stated. Energy recovery consituted at the end of the heat storage test almost 50 % - without considering the influx of the cold reservoir water. Recovery rates of the fluorescent dyes are linked to their different sorption behaviour and variied between 23 % up to 79 %. The tracers are an additional tool for interpreting the groundwater flows and matrix interaction in the aquifer.

[Application of natural plant pigment in hair dyes].

PubMed

Hu, Yu-Li; Luo, Jiao-Yang; Zhao, Hong-Zheng; Zhang, Shan-Shan; Yang, Shi-Hai; Yang, Mei-Hua

2016-09-01

With the development of living condition, more and more people tend to show unique personality, thus hair dyes as hair cosmetics are highly favored. By the year 2012, the global sales of hair dye had exceeded $15 billion, with a sustained growth at a rate of 8%-10% annually. However, the harm caused by long-term use of hair dyes has aroused widespread public concern, so people begin to seek non-toxic or low toxic natural plant hair dyes. The types of commonly used hair dyes and the corresponding dyeing mechanisms were summarized in this manuscript, and the representative natural botanic dyes were listed. Thereafter, their effective fractions, constituents and application status were described. In addition, the values of botanic hair dyes and their broad market prospect were discussed. Finally, the problems that exist in the research and development of plant hair dyes were issued. This review may help to provide thought for developing novel, green and ecological natural plant hair dyes. Copyright© by the Chinese Pharmaceutical Association.

Spectroscopic detection of halogen bonding resolves dye regeneration in the dye-sensitized solar cell.

PubMed

Parlane, Fraser G L; Mustoe, Chantal; Kellett, Cameron W; Simon, Sarah J; Swords, Wesley B; Meyer, Gerald J; Kennepohl, Pierre; Berlinguette, Curtis P

2017-11-24

The interactions between a surface-adsorbed dye and a soluble redox-active electrolyte species in the dye-sensitized solar cell has a significant impact on the rate of regeneration of photo-oxidized dye molecules and open-circuit voltage of the device. Dyes must therefore be designed to encourage these interfacial interactions, but experimentally resolving how such weak interactions affect electron transfer is challenging. Herein, we use X-ray absorption spectroscopy to confirm halogen bonding can exist at the dye-electrolyte interface. Using a known series of triphenylamine-based dyes bearing halogen substituents geometrically positioned for reaction with halides in solution, halogen bonding was detected only in cases where brominated and iodinated dyes were photo-oxidized. This result implies that weak intermolecular interactions between photo-oxidized dyes and the electrolyte can impact device photovoltages. This result was unexpected considering the low concentration of oxidized dyes (less than 1 in 100,000) under full solar illumination.

Theoretical study of electronic transfer current rate at dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

AL-Agealy, Hadi J. M.; AlMaadhede, Taif Saad; Hassooni, Mohsin A.; Sadoon, Abbas K.; Ashweik, Ahmed M.; Mahdi, Hind Abdlmajeed; Ghadhban, Rawnaq Qays

2018-05-01

In this research, we present a theoretical study of electronic transfer kinetics rate in N719/TiO2 and N719/ZnO dye-sensitized solar cells (DSSC) systems using a simple model depending on the postulate of quantum mechanics theory. The evaluation of the electronic transition current rate in DSSC systems are function of many parameters such that; the reorientation transition energies ΛSe m D y e , the transition coupling parameter ℂT(0), potential exponential effect e-(E/C-EF ) kBT , unit cell volume VSem, and temperature T. Furthermore, the analysis of electronic transfer current rate in N719/TiO2 and N719/ZnO systems show that the rate upon dye-sensitization solar cell increases with increases of transition coupling parameter, decreasing potential that building at interface a results of different material in this devices and increasing with reorientation transition energy. On the other hand, we can find the electronic transfer behavior is dependent of the dye absorption spectrum and mainly depending on the reorientation of transition energy. The replacement of the solvents in both DSSC system caused increasing of current rates dramatically depending on polarity of solvent in subset devices. This change in current rate of electron transfer were attributed to much more available of recombination sites introduced by the solvents medium. The electronic transfer current dynamics are shown to occurs in N719/TiO2 system faster many time compare to ocuures at N719/ZnO system, this indicate that TiO2 a is a good and active material compare with ZnO to using in dye sensitized solar cell devices. In contrast, the large current rate in N719/TiO2 comparing to ZnO of N719/ZnO systems indicate that using TiO2 with N719 dye lead to increasing the efficiency of DSSC.

Synthesis and swelling characteristics of chitosan and CMC grafted sodium acrylate-co-acrylamide using modified nanoclay and examining its efficacy for removal of dyes.

PubMed

Nagarpita, M V; Roy, Pratik; Shruthi, S B; Sailaja, R R N

2017-09-01

Chitosan/carboxy methyl chitosan (CMC) grafted sodium acrylate-co-acrylamide/nanoclay superabsorbent nanocomposites have been synthesized in this study by following conventional and microwave assisted grafting methods. Microwave assisted grafting method showed higher grafting yield with enhanced reaction rate. Effect of nanoclay on water adsorption and swelling behaviour of both the composites in acidic, neutral and alkaline medium has been studied. Results showed enhanced swelling rate and water adsorption of both composites after adding 5% of silane treated nanoclay. Dye adsorption capacity of both the composites has been investigated for crystal violet, napthol green and sunset yellow dyes. It was observed that addition of 5% nanoclay enhanced the dye adsorption in both the composites. Langmuir and Freundlich isotherm models have been used to explain the dye adsorption capabilities. The chitosan and CMC nanocomposites follow both the models with R 2 value more than 0.97. Both the composites showed enhanced dye adsorption with 5% nanoclay. Effect of pH on dye adsorption has also been studied in both the composites. Chitosan nanocomposites showed better performance in dye removal as compared to CMC nanocomposites. Copyright © 2017 Elsevier B.V. All rights reserved.

The factors influencing nonlinear characteristics of the short-circuit current in dye-sensitized solar cells investigated by a numerical model.

PubMed

Shi, Yushuai; Dong, Xiandui

2013-06-24

A numerical model for interpretation of the light-intensity-dependent nonlinear characteristics of the short-circuit current in dye-sensitized solar cells is suggested. The model is based on the continuity equation and includes the influences of the nongeminate recombination between electrons and electron acceptors in the electrolyte and the geminate recombination between electrons and oxidized dye molecules. The influences of the order and rate constant of the nongeminate recombination reaction, the light-absorption coefficient of the dye, the film thickness, the rate constant of geminate recombination, and the regeneration rate constant on the nonlinear characteristics of the short-circuit current are simulated and analyzed. It is proposed that superlinear and sublinear characteristics of the short-circuit current should be attributed to low electron-collection efficiency and low dye-regeneration efficiency, respectively. These results allow a deep understanding of the origin of the nonlinear characteristics of the short-circuit current in solar cells. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A measurement and modeling study of temperature in living and fixed tissue during and after radiofrequency exposure.

PubMed

Bermingham, Jacqueline F; Chen, Yuen Y; McIntosh, Robert L; Wood, Andrew W

2014-04-01

Fluorescent intensity of the dye Rhodamine-B (Rho-B) decreases with increasing temperature. We show that in fresh rat brain tissue samples in a custom-made radiofrequency (RF) tissue exposure device, temperature rise due to RF radiation as measured by absorbed dye correlates well with temperature measured nearby by fiber optic probes. Estimates of rate of initial temperature rise (using both probe measurement and the dye method) accord well with estimates of local specific energy absorption rate (SAR). We also modeled the temperature characteristics of the exposure device using combined electromagnetic and finite-difference thermal modeling. Although there are some differences in the rate of cooling following cessation of RF exposure, there is reasonable agreement between modeling and both probe measurement and dye estimation of temperature. The dye method also permits measurement of regional temperature rise (due to RF). There is no clear evidence of local differential RF absorption, but further refinement of the method may be needed to fully clarify this issue. © 2014 Wiley Periodicals, Inc.

An Improved Flow Cytometry Method For Precise Quantitation Of Natural-Killer Cell Activity

NASA Technical Reports Server (NTRS)

Crucian, Brian; Nehlsen-Cannarella, Sandra; Sams, Clarence

2006-01-01

The ability to assess NK cell cytotoxicity using flow cytometry has been previously described and can serve as a powerful tool to evaluate effector immune function in the clinical setting. Previous methods used membrane permeable dyes to identify target cells. The use of these dyes requires great care to achieve optimal staining and results in a broad spectral emission that can make multicolor cytometry difficult. Previous methods have also used negative staining (the elimination of target cells) to identify effector cells. This makes a precise quantitation of effector NK cells impossible due to the interfering presence of T and B lymphocytes, and the data highly subjective to the variable levels of NK cells normally found in human peripheral blood. In this study an improved version of the standard flow cytometry assay for NK activity is described that has several advantages of previous methods. Fluorescent antibody staining (CD45FITC) is used to positively identify target cells in place of membranepermeable dyes. Fluorescent antibody staining of target cells is less labor intensive and more easily reproducible than membrane dyes. NK cells (true effector lymphocytes) are also positively identified by fluorescent antibody staining (CD56PE) allowing a simultaneous absolute count assessment of both NK cells and target cells. Dead cells are identified by membrane disruption using the DNA intercalating dye PI. Using this method, an exact NK:target ratio may be determined for each assessment, including quantitation of NK target complexes. Backimmunoscatter gating may be used to track live vs. dead Target cells via scatter properties. If desired, NK activity may then be normalized to standardized ratios for clinical comparisons between patients, making the determination of PBMC counts or NK cell percentages prior to testing unnecessary. This method provides an exact cytometric determination of NK activity that highly reproducible and may be suitable for routine use in the clinical setting.

Adsorption of dissolved Reactive red dye from aqueous phase onto activated carbon prepared from agricultural waste.

PubMed

Senthilkumaar, S; Kalaamani, P; Porkodi, K; Varadarajan, P R; Subburaam, C V

2006-09-01

The adsorption of Reactive red dye (RR) onto Coconut tree flower carbon (CFC) and Jute fibre carbon (JFC) from aqueous solution was investigated. Adsorption studies were carried out at different initial dye concentrations, initial solution pH and adsorbent doses. The kinetic studies were also conducted; the adsorption of Reactive red onto CFC and JFC followed pseudosecond-order rate equation. The effective diffusion coefficient was evaluated to establish the film diffusion mechanism. Quantitative removal of Reactive red dye was achieved at strongly acidic conditions for both the carbons studied. The adsorption isotherm data were fitted well to Langmuir isotherm and the adsorption capacity were found to be 181.9 and 200 mg/g for CFC and JFC, respectively. The overall rate of dye adsorption appeared to be controlled by chemisorption, in this case in accordance with poor desorption studies.

Preparation of ZnO Photocatalyst for the Efficient and Rapid Photocatalytic Degradation of Azo Dyes.

PubMed

Chen, Xiaoqing; Wu, Zhansheng; Liu, Dandan; Gao, Zhenzhen

2017-12-01

Zinc oxide (ZnO) photocatalysts were synthesized by sol-gel method using zinc acetate as precursor for degradation of azo dyes under UV irradiation. The resultant samples were characterized by different techniques, such as XRD, SEM, and EDX. The influence of preparation conditions such as calcination temperature and composite ratio on the degradation of methyl orange (MO) was investigated. ZnO prepared with a composite ratio of 4:1 and calcination temperature of 400 °C exhibited 99.70% removal rate for MO. The effect of operation parameters on the degradation was also studied. Results showed that the removal rate of azo dyes increased with the increased dosage of catalyst and decreased initial concentration of azo dyes and the acidic condition is favorable for degradation. Furthermore, the kinetics and scavengers of the reactive species during the degradation were also investigated. It was found that the degradation of azo dyes fitted the first-order kinetics and superoxide ions were the main species. The proposed photocatalyst can efficiently and rapidly degrade azo dyes; thus, this economical and environment-friendly photocatalyst can be applied to the treatment of wastewater contaminated with synthetic dyes.

UV reactor flow visualization and mixing quantification using three-dimensional laser-induced fluorescence.

PubMed

Gandhi, Varun; Roberts, Philip J W; Stoesser, Thorsten; Wright, Harold; Kim, Jae-Hong

2011-07-01

Three-dimensional laser-induced fluorescence (3DLIF) was applied to visualize and quantitatively analyze mixing in a lab-scale UV reactor consisting of one lamp sleeve placed perpendicular to flow. The recirculation zone and the von Karman vortex shedding that commonly occur in flows around bluff bodies were successfully visualized. Multiple flow paths were analyzed by injecting the dye at various heights with respect to the lamp sleeve. A major difference in these pathways was the amount of dye that traveled close to the sleeve, i.e., a zone of higher residence time and higher UV exposure. Paths away from the center height had higher velocities and hence minimal influence by the presence of sleeve. Approach length was also characterized in order to increase the probability of microbes entering the region around the UV lamp. The 3DLIF technique developed in this study is expected to provide new insight on UV dose delivery useful for the design and optimization of UV reactors. Copyright © 2011 Elsevier Ltd. All rights reserved.

Thermal injury decreases hepatic blood flow and the intrinsic clearance of indocyanine green in the rat.

PubMed

Pollack, G M; Brouwer, K L

1991-01-01

The influence of severe thermal injury (full-thickness burns involving 50% of the body surface area) on hepatic blood flow in the rat was assessed using the tricarbocyanine dye indocyanine green (ICG). In a randomized crossover fashion, rats received sequential infusions of ICG through both the femoral vein and the portal vein, allowing the estimation of total hepatic plasma clearance and transhepatic extraction of the dye. These two parameters, along with the hematocrit, were used to calculate intrinsic hepatic clearance of ICG and hepatic blood flow. Animals were examined at 0 (control), 0.5, 12, or 24 hr following infliction of scald burns. Hepatic blood flow was decreased significantly by 0.5 hr postburn and remained approximately 20% below normal throughout the remainder of the study. The intrinsic efficiency of the liver in removing ICG from the systemic circulation was also decreased by thermal injury. The potential mechanisms involved in these two physiologic perturbations are discussed.

Experimental studying of local characteristics of gas-liquid flow in microchannels by optical methods

NASA Astrophysics Data System (ADS)

Bartkus, German V.; Kuznetsov, Vladimir V.

2018-03-01

The local characteristics of the gas-liquid two-phase flow in rectangular microchannels 420 × 280 μm and 395 × 205 μm with T-shaped mixer inlet were experimentally investigated in this work. Visualization of flow regimes and measurement of local characteristics were carried out using a high-speed video camera Optronis CX600x2 and laser-induced fluorescence (LIF) method. Deionized water and ethanol were used as the liquid phase, and nitrogen - as the gas phase. The Rhodamine 6G dye was added to the liquid. The location of the microchannel in space (horizontal, vertical) was changed. The profiles of the liquid film along the long side of the microchannel were obtained, the local film thickness was measured in the channel`s central section for the elongated bubble flow and the transition flow of the deionized water-nitrogen mixture. The unevenness of liquid film thickness at the channel cross-section and along the bubble was experimentally shown. The temporal dynamics of two-phase flow for the ethanol-nitrogen mixture was shown. It was found that most of the liquid flows in the meniscus on the short side of the microchannel for the present gas and liquid flow rates.

A simple method for purification of vestibular hair cells and non-sensory cells, and application for proteomic analysis.

PubMed

Herget, Meike; Scheibinger, Mirko; Guo, Zhaohua; Jan, Taha A; Adams, Christopher M; Cheng, Alan G; Heller, Stefan

2013-01-01

Mechanosensitive hair cells and supporting cells comprise the sensory epithelia of the inner ear. The paucity of both cell types has hampered molecular and cell biological studies, which often require large quantities of purified cells. Here, we report a strategy allowing the enrichment of relatively pure populations of vestibular hair cells and non-sensory cells including supporting cells. We utilized specific uptake of fluorescent styryl dyes for labeling of hair cells. Enzymatic isolation and flow cytometry was used to generate pure populations of sensory hair cells and non-sensory cells. We applied mass spectrometry to perform a qualitative high-resolution analysis of the proteomic makeup of both the hair cell and non-sensory cell populations. Our conservative analysis identified more than 600 proteins with a false discovery rate of <3% at the protein level and <1% at the peptide level. Analysis of proteins exclusively detected in either population revealed 64 proteins that were specific to hair cells and 103 proteins that were only detectable in non-sensory cells. Statistical analyses extended these groups by 53 proteins that are strongly upregulated in hair cells versus non-sensory cells and vice versa by 68 proteins. Our results demonstrate that enzymatic dissociation of styryl dye-labeled sensory hair cells and non-sensory cells is a valid method to generate pure enough cell populations for flow cytometry and subsequent molecular analyses.

Measuring Solvent Content of Macromolecular Crystals Using Fluorescence Recovery after Photobleaching

NASA Astrophysics Data System (ADS)

Siewny, Matthew; Kmetko, Jan

2010-10-01

We work out a novel protocol for measuring the solvent content (the fraction of crystal volume occupied by solvent) in biological crystals by the technique of fluorescence recovery after photobleaching (FRAP). Crystals of proteins with widely varying known solvent content (lysozyme, thaumatin, catalase, and ferritin) were grown in their native solution doped with sodium fluorescein dye and hydroxylamine (to prevent dye from binding to amine groups of the proteins.) The crystals were irradiated by a broadband, high intensity light through knife slits, leaving a rectangular area of bleached dye within the crystals. Measuring the flow of dye out of the bleached area allowed us to construct a curve relating the diffusion coefficient of dye to the channel size within the crystals, by solving the diffusion equation analytically. This curve may be used to measure the solvent content of any biological crystal in its native solution and help determine the number of proteins in the crystallographic asymmetric unit cell in x-ray structure solving procedures.

Vortex scale of unsteady separation on a pitching airfoil.

PubMed

Fuchiwaki, Masaki; Tanaka, Kazuhiro

2002-10-01

The streaklines of unsteady separation on two kinds of pitching airfoils, the NACA65-0910 and a blunt trailing edge airfoil, were studied by dye flow visualization and by the Schlieren method. The latter visualized the discrete vortices shed from the leading edge. The results of these visualization studies allow a comparison between the dynamic behavior of the streakline of unsteady separation and that of the discrete vortices shed from the leading edge. The influence of the airfoil configuration on the flow characteristics was also examined. Furthermore, the scale of a discrete vortex forming the recirculation region was investigated. The non-dimensional pitching rate was k = 0.377, the angle of attack alpha(m) = 16 degrees and the pitching amplitude was fixed to A = +/-6 degrees for Re = 4.0 x 10(3) in this experiment.

Measured flow and tracer-dye data for spring 1996 and 1997 for the south Sacramento-San Joaquin Delta, California

USGS Publications Warehouse

Oltmann, Richard N.

1999-01-01

During the spring of years when the flow of the San Joaquin River is less than 7,000 cubic feet per second (ft3/s) a temporary rock barrier is installed by the California Department of Water Resources (DWR) at the head of Old River (HOR) in the south Sacramento-San Joaquin Delta to prevent out migrating salmon in the San Joaquin River from entering Old River and being drawn to the State and federal pumping facilities (Figure 1). The export rate of the pumping facilities also is reduced during these migration periods to minimize the draw of fish to the export facilities through the other channels connected to the San Joaquin River north of the HOR such as Turner Cut, Columbia Cut, and Middle River.

Numerical simulation of double‐diffusive finger convection

USGS Publications Warehouse

Hughes, Joseph D.; Sanford, Ward E.; Vacher, H. Leonard

2005-01-01

A hybrid finite element, integrated finite difference numerical model is developed for the simulation of double‐diffusive and multicomponent flow in two and three dimensions. The model is based on a multidimensional, density‐dependent, saturated‐unsaturated transport model (SUTRA), which uses one governing equation for fluid flow and another for solute transport. The solute‐transport equation is applied sequentially to each simulated species. Density coupling of the flow and solute‐transport equations is accounted for and handled using a sequential implicit Picard iterative scheme. High‐resolution data from a double‐diffusive Hele‐Shaw experiment, initially in a density‐stable configuration, is used to verify the numerical model. The temporal and spatial evolution of simulated double‐diffusive convection is in good agreement with experimental results. Numerical results are very sensitive to discretization and correspond closest to experimental results when element sizes adequately define the spatial resolution of observed fingering. Numerical results also indicate that differences in the molecular diffusivity of sodium chloride and the dye used to visualize experimental sodium chloride concentrations are significant and cause inaccurate mapping of sodium chloride concentrations by the dye, especially at late times. As a result of reduced diffusion, simulated dye fingers are better defined than simulated sodium chloride fingers and exhibit more vertical mass transfer.

Simultaneous velocity and pressure quantification using pressure-sensitive flow tracers in air

NASA Astrophysics Data System (ADS)

Zhang, Peng; Peterson, Sean; Porfiri, Maurizio

2017-11-01

Particle-based measurement techniques for assessing the velocity field of a fluid have advanced rapidly over the past two decades. Full-field pressure measurement techniques have remained elusive, however. In this work, we aim to demonstrate the possibility of direct simultaneous planar velocity and pressure measurement of a high speed aerodynamic flow by employing novel pressure-sensitive tracer particles for particle image velocimetry (PIV). Specifically, the velocity and pressure variations of an airflow through a converging-diverging channel are studied. Polystyrene microparticles embedded with a pressure-sensitive phosphorescent dye-platinum octaethylporphyrin (PtOEP)-are used as seeding particles. Due to the oxygen quenching effect, the emission lifetime of PtOEP is highly sensitive to the oxygen concentration, that is, the partial pressure of oxygen, in the air. Since the partial pressure of oxygen is linearly proportional to the air pressure, we can determine the air pressure through the phosphorescence emission lifetime of the dye. The velocity field is instead obtained using traditional PIV methods. The particles have a pressure resolution on the order of 1 kPa, which may be improved by optimizing the particle size and dye concentration to suit specific flow scenarios. This work was supported by the National Science Foundation under Grant Number CBET-1332204.

Polyester Fabric's Fluorescent Dyeing in Supercritical Carbon Dioxide and its Fluorescence Imaging.

PubMed

Xiong, Xiaoqing; Xu, Yanyan; Zheng, Laijiu; Yan, Jun; Zhao, Hongjuan; Zhang, Juan; Sun, Yanfeng

2017-03-01

As one of the most important coumarin-like dyes, disperse fluorescent Yellow 82 exhibits exceptionally large two-photon effects. Here, it was firstly introduced into the supercritical CO 2 dyeing polyester fabrics in this work. Results of the present work showed that the dyeing parameters such as the dyeing time, pressure and temperature had remarkable influences on the color strength of fabrics. The optimized dyeing condition in supercritical CO 2 dyeing has been proposed that the dyeing time was 60 min; the pressure was 25 MPa and the temperature was 120 °C. As a result, acceptable products were obtained with the wash and rub fastness rating at 5 or 4-5. The polyester fabrics dyed with fluorescent dyes can be satisfied for the requirement of manufacturing warning clothing. Importantly, the confocal microscopy imaging technology was successfully introduced into textile fields to observe the distribution and fluorescence intensity of disperse fluorescent Yellow 82 on polyester fabrics. As far as we know, this is the first report about supercritical CO 2 dyeing polyester fabrics based on disperse fluorescent dyes. It will be very helpful for the further design of new fluorescent functional dyes suitable for supercritical CO 2 dyeing technique.

Kinetics of zero-valent iron reductive transformation of the anthraquinone dye Reactive Blue 4.

PubMed

Epolito, William J; Yang, Hanbae; Bottomley, Lawrence A; Pavlostathis, Spyros G

2008-12-30

The effect of operational conditions and initial dye concentration on the reductive transformation (decolorization) of the textile dye Reactive Blue 4 (RB4) using zero-valent iron (ZVI) filings was evaluated in batch assays. The decolorization rate increased with decreasing pH and increasing temperature, mixing intensity, and addition of salt (100gL(-1) NaCl) and base (3gL(-1) Na2CO3 and 1gL(-1) NaOH), conditions typical of textile reactive dyebaths. ZVI RB4 decolorization kinetics at a single initial dye concentration were evaluated using a pseudo first-order model. Under dyebath conditions and at an initial RB4 concentration of 1000mgL(-1), the pseudo first-order rate constant (kobs) was 0.029+/-0.006h(-1), corresponding to a half-life of 24.2h and a ZVI surface area-normalized rate constant (kSA) of 2.9x10(-4)Lm(-2)h(-1). However, as the initial dye concentration increased, the kobs decreased, suggesting saturation of ZVI surface reactive sites. Non-linear regression of initial decolorization rate values as a function of initial dye concentration, based on a reactive sites saturation model, resulted in a maximum decolorization rate (Vm) of 720+/-88mgL(-1)h(-1) and a half-saturation constant (K) of 1299+/-273mgL(-1). Decolorization of RB4 via a reductive transformation, which was essentially irreversible (2-5% re-oxidation), is believed to be the dominant decolorization mechanism. However, some degree of RB4 irreversible sorption cannot be completely discounted. The results of this study show that ZVI treatment is a promising technology for the decolorization of commercial, anthraquinone-bearing, spent reactive dyebaths.

Measurements of atmospheric nitrous acid and nitric acid

NASA Astrophysics Data System (ADS)

Huang, Gu; Zhou, Xianliang; Deng, Guohong; Qiao, Huancheng; Civerolo, Kevin

A highly sensitive technique for the measurement of atmospheric HONO and HNO 3 is reported. The technique is based on aqueous scrubbing using two coil samplers, followed by conversion of HNO 3 to nitrite, derivatization of nitrite to a highly light-absorbing azo dye with sulfanilamide (SA) and N-(1-naphthyl) ethylenediamine (NED), and high performance liquid chromatography (HPLC) analysis. HNO 3 concentration was obtained by the difference of the two channels. Two scrubbing solutions were used for sampling the two species: a 1-mM phosphate buffer solution (pH 7) for the measurement of HONO and a 180 mM NH 4Cl/NH 3 buffer solution (pH 8.5) for the measurement of HONO+HNO 3. The scrubbing solution flow rate was 0.24 ml min -1 and the gas sampling flow rate was 2 l min -1. HNO 3 in the NH 4Cl/NH 3 buffer solution was quantitatively reduced to nitrite along an on-line 0.8-cm Cd reductor column. Nitrite in both channels was derivatized with 2 mM SA and 0.2 mM NED in 25 mM HCl. Quantitative derivatization was achieved within 5 min at 55°C. The azo dye derivative was then separated from the SA/NED reagent by reversed-phase HPLC and detected with a UV-vis detector at 540 nm. With an on-line SEP-PAK C-18 cartridge for the reagent purification, the method detection limit is estimated to be better than 1 pptv for HONO and about 20 pptv for HNO 3. The sample integration time was about 2 min and the sampling frequency is every 10 min. Data collected in downtown Albany and Whiteface Mountain, NY, are shown as examples of applications of this technique in both urban and remote clean environments.

Water Tunnel Flow Visualization Study Through Poststall of 12 Novel Planform Shapes

NASA Technical Reports Server (NTRS)

Gatlin, Gregory M.; Neuhart, Dan H.

1996-01-01

To determine the flow field characteristics of 12 planform geometries, a flow visualization investigation was conducted in the Langley 16- by 24-Inch Water Tunnel. Concepts studied included flat plate representations of diamond wings, twin bodies, double wings, cutout wing configurations, and serrated forebodies. The off-surface flow patterns were identified by injecting colored dyes from the model surface into the free-stream flow. These dyes generally were injected so that the localized vortical flow patterns were visualized. Photographs were obtained for angles of attack ranging from 10' to 50', and all investigations were conducted at a test section speed of 0.25 ft per sec. Results from the investigation indicate that the formation of strong vortices on highly swept forebodies can improve poststall lift characteristics; however, the asymmetric bursting of these vortices could produce substantial control problems. A wing cutout was found to significantly alter the position of the forebody vortex on the wing by shifting the vortex inboard. Serrated forebodies were found to effectively generate multiple vortices over the configuration. Vortices from 65' swept forebody serrations tended to roll together, while vortices from 40' swept serrations were more effective in generating additional lift caused by their more independent nature.

Electrochemical oxidation of bio-refractory dye in a simulated textile industry effluent using DSA electrodes in a filter-press type FM01-LC reactor.

PubMed

Rodríguez, Francisca A; Mateo, María N; Aceves, Juan M; Rivero, Eligio P; González, Ignacio

2013-01-01

This work presents a study on degradation of indigo carmine dye in a filter-press type FM01-LC reactor using Sb2O5-doped Ti/IrO2-SnO2 dimensionally stable anode (DSA) electrodes. Micro- and macroelectrolysis studies were carried out using solutions of 0.8 mM indigo carmine in 0.05 M NaCl, which resemble blue denim laundry industrial wastewater. Microelectrolysis results show the behaviour of DSA electrodes in comparison with the behaviour of boron-doped diamond (BDD) electrodes. In general, dye degradation reactions are carried out indirectly through active chlorine generated on DSA, whereas in the case of BDD electrodes more oxidizing species are formed, mainly OH radicals, on the electrode surface. The well-characterized geometry, flow pattern and mass transport of the FM01-LC reactor used in macroelectrolysis experiments allowed the evaluation of the effect of hydrodynamic conditions on the chlorine-mediated degradation rate. Four values of Reynolds number (Re) (93, 371, 464 and 557) at four current densities (50, 100, 150 and 200 A/m2) were tested. The results show that the degradation rate is independent of Re at low current density (50 A/m2) but becomes dependent on the Re at high current density (200 A/m2). This behaviour shows the central role of mass transport and the reactor parameters and design. The low energy consumption (2.02 and 9.04 kWh/m3 for complete discolouration and chemical oxygen demand elimination at 50 A/m2, respectively) and the low cost of DSA electrodes compared to BDD make DSA electrodes promising for practical application in treating industrial textile effluents. In the present study, chlorinated organic compounds were not detected.

Thin Crystal Film Polarizer for Display Application

NASA Astrophysics Data System (ADS)

Paukshto, Michael

2003-03-01

Optiva Inc. has pioneered the development of nano-thin crystalline film (TCF) optical coatings for use in information displays and other applications. TCF is a material based on water-based dichroic dye solutions. Disk-like dye molecules aggregate in a ``plane-to-plane" manner; this self-assembly results in formation of highly anisometric rod-like stacks. These stacks have an aspect ratio of approximately 200:1. At a certain threshold of dye concentration, a nematic ordering of the rod-like stacks appears. Such a system acquires polarizing properties according to the following mechanism. Flow-induced alignment is known to occur in the lyotropic systems in a shear flow. In our case, the material undergoes shear alignment while being coated onto a glass or plastic substrate. In the coated thin film, the long molecular stacks are oriented in the flow direction parallel to the flow direction and substrate plane. The planes of the dye molecules are perpendicular to the substrate plane with the optical transition oscillators lying in the molecule plane. After the coating, as the thin film dries, crystallization occurs due to water evaporation. In a dry film, the molecular planes maintain their orthogonal orientation with respect to the substrate surface. TCF is known to possess properties of an E-mode polarizer. TCF technology has now migrated out of the R stage into manufacturing and is currently being incorporated into new display products. This presentation will provide an overview of TCF technology. The first part of the presentation will describe material structure, optical properties and characterization, material processing and associated coating equipment. This will be followed by a presentation on optical modeling and simulation of display performance with TCF components. Comparisons of display performance will be made for exemplar configurations of a variety of LCDs, including TN, STN and AMLCD designs in both transmissive and reflective modes.

Mediator-assisted decolorization and detoxification of textile dyes/dye mixture by Cyathus bulleri laccase.

PubMed

Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, T R

2008-12-01

Laccase from basidiomycete fungus Cyathus bulleri was evaluated for its ability to decolorize a number of reactive and acidic dyes in the presence of natural and synthetic mediators. The extent of decolorization was monitored at different mediator/dye concentrations and incubation time. Among the synthetic mediators, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) was effective at low mediator/dye ratios and resulted in 80-95% decolorization at rates that varied from 226 +/- 4 nmol min(-1) mg(-1) for Reactive Orange 1 to 1,333 +/- 15 nmol min(-1) mg(-1) for Reactive Red 198. Other synthetic mediators like 1-hydroxybenzotriazole and violuric acid showed both concentration- and time-dependent increases in percent decolorization. Natural mediators like vanillin, on the other hand, were found to be less effective on all the dyes except Reactive Orange 1. Computed rates of decolorization were about twofold lower than that with ABTS. The laccase-ABTS system also led to nearly 80% decolorization for the simulated dye mixture. No clear correlation between laccase activity on the mediator and its ability to decolorize dyes was found, but pH had a significant effect: Optimum pH for decolorization coincided with the optimum pH for mediator oxidation. The treated samples were also evaluated for toxicity in model microbial systems. The laccase-mediator system appears promising for treatment of textile wastewaters.

Trinity Bay Study: Dye tracing experiments

NASA Technical Reports Server (NTRS)

Ward, G. H., Jr.

1972-01-01

An analysis of the heat balance and temperature distribution within Trinity Bay near Galveston, Texas is presented. The effects of tidal currents, wind driven circulations, and large volume inflows are examined. Emphasis is placed on the effects of turbulent diffusion and local shears in currents. The technique of dye tracing to determine the parameters characterizing dispersion is described. Aerial photographs and maps are provided to show the flow conditions existing at different times and seasons.

Characterization of ground-water flow and water quality for the Madison and Minnelusa aquifers in northern Lawrence County, South Dakota

USGS Publications Warehouse

Putnam, Larry D.; Long, Andrew J.

2007-01-01

The Madison and Minnelusa aquifers are used extensively for water supplies for the city of Spearfish and other users in northern Lawrence County, South Dakota. Ground water in the Madison and Minnelusa aquifers in the study area generally flows north from outcrop areas where recharge from sinking streams and infiltration of precipitation occurs. Ground water that moves northward and eastward around the Black Hills enters the study area from the west and results in hydraulic heads that are several hundred feet higher on the western side of the study area than on the eastern side. The estimated average recharge rate of 38 cubic feet per second (ft3/s) on outcrops of the Madison Limestone and Minnelusa Formation is less than the total estimated average spring discharge rate of 51 ft3/s in the northwestern part of the study area. Sixteen pounds of fluorescein dye were injected into Spearfish Creek on March 25, 2003, when streamflow was 6.6 ft3/s. The dye was detected in water samples from four wells completed in the Madison aquifer ranging from 2.6 to 4.5 miles north of the injection site. First arrival times ranged from 5 to 169 days, and ground-water velocities ranged from about 0.1 to 0.5 mile per day. Sixty-four pounds of Rhodamine WT was injected into Spearfish Creek at the same location on May 9, 2003, when streamflow was 5.6 ft3/s. Rhodamine WT dye concentrations measured in samples from the same four wells were about an order of magnitude less than measured fluorescein concentrations. Oxygen- and deuterium-isotope values for samples from Cox Lake and McNenny Pond springs indicated a probable component of spring discharge that originates from outcrops of the Madison Limestone and Minnelusa Formation on the Limestone Plateau south of the study area. Oxygen- and deuterium-isotope values for samples from Mirror Lake spring indicated possible contributions from overlying aquifers and local recharge. Oxygen- and deuterium-isotope values for the combined springflow contributing to Crow Creek in the northwestern part of the study area indicated that the primary source of water is the Madison and Minnelusa aquifers. Oxygen- and deuterium-isotope values for Old Hatchery and Higgins Gulch springs, located north of Spearfish, indicated a source water originating from the outcrops of the Madison Limestone and Minnelusa Formation within the study area. Concentrations of three chlorofluorocarbons (CFC-11, CFC-12, and CFC-113) were used to characterize ground-water residence times in the study area. For the four wells where dye was detected, CFC-11 apparent ages ranged from 12 to 26 years, indicating that the wells contained months-old water mixed with years- to decades-old water. Logarithmic regression analysis of the CFC-11 apparent ages for water from 10 wells and distance to a possible conduit trending north through the area where dye was detected, yielded an r2 value of 0.71. Straight-line regression analysis of the CFC-11 apparent ages for the six wells closest to the possible conduit had an r2 value of 0.96. Two wells located relatively close to the outcrop areas had no or very low tritium values indicating relatively long residence times and diffuse ground-water flow. The tritium value of 7.2 TU in water from well COL where dye was detected, indicated that the water probably is a bimodal mixture, with a substantial portion that is older than 50 years. Water from well ELL, where dye was detected, had a tritium value of 19.7 TU and a CFC apparent age of 15 years, indicating that the sample from this well probably is a unimodal mixture with very little water older than 50 years. Comparison of the CFC apparent age for three spring sites (Cox Lake, 26 years; McNenny Pond, 26 years; Mirror Lake, 13 years) also indicated that Mirror Lake spring probably has a component of local recharge from formations that overlie the Minnelusa Formation. In the Madison aquifer, specific conductance ranges from 18 to 945 microsiemens per cen

Voltage-sensitive styryl dyes as singlet oxygen targets on the surface of bilayer lipid membrane.

PubMed

Sokolov, V S; Gavrilchik, A N; Kulagina, A O; Meshkov, I N; Pohl, P; Gorbunova, Yu G

2016-08-01

Photosensitizers are widely used as photodynamic therapeutic agents killing cancer cells by photooxidation of their components. Development of new effective photosensitive molecules requires profound knowledge of possible targets for reactive oxygen species, especially for its singlet form. Here we studied photooxidation of voltage-sensitive styryl dyes (di-4-ANEPPS, di-8-ANEPPS, RH-421 and RH-237) by singlet oxygen on the surface of bilayer lipid membranes commonly used as cell membrane models. Oxidation was induced by irradiation of a photosensitizer (aluminum phthalocyanine tetrasulfonate) and monitored by the change of dipole potential on the surface of the membrane. We studied the drop of the dipole potential both in the case when the dye molecules were adsorbed on the same side of the lipid bilayer as the photosensitizer (cis-configuration) and in the case when they were adsorbed on the opposite side (trans-configuration). Based on a simple model, we determined the rate of oxidation of the dyes from the kinetics of change of the potential during and after irradiation. This rate is proportional to steady-state concentration of singlet oxygen in the membrane under irradiation. Comparison of the oxidation rates of various dyes reveals that compounds of ANEPPS series are more sensitive to singlet oxygen than RH type dyes, indicating that naphthalene group is primarily responsible for their oxidation. Copyright © 2016 Elsevier B.V. All rights reserved.

Hydrogeological characterization of flow system in a karstic aquifer, Seymareh dam, Iran

NASA Astrophysics Data System (ADS)

Behrouj Peely, Ahmad; Mohammadi, Zargham; Raeisi, Ezzatollah; Solgi, Khashayar; Mosavi, Mohammad J.; Kamali, Majid

2018-07-01

In order to determine the characteristics of the flow system in a karstic aquifer, an extensive hydrogeological study includes dye tracing test was conducted. The aquifer suited left abutment of Seymareh Dam, in Ravandi Anticline and discharges by more than 50 springs in the southern flank. Flow system in the aquifer is mainly controlled by the reservoir of Seymareh Dam. Time variations of the spring discharge and water table in the observation wells were highly correlated with the reservoir water level. The average groundwater velocity ranges from 0.2 to more than 14 m/h based on the dye tracing test. The probable flow paths were differentiated in two groups including the flow paths in the northern and southern flanks of Ravandi Anticline. Types of groundwater flow in the proposed flow paths are determined as diffuse or conduit flow type considering groundwater velocity and shape of the breakthrough curves. An index is proposed for differentiation of diffuse and conduit flow system based on relationship of groundwater velocity and hydraulic gradient. Dominant geometry of the flow routs (e.g., conduit diameter and fracture aperture) is estimated for the groundwater flow paths toward the springs. Based on velocity variations and variance coefficient of the water table and discharge of springs on map view a major karst conduit was probably developed in the aquifer. This research emphasizes applying of an extensive hydrogeological study for characterization of flow system in the karst aquifer.

Photodegradation mechanism and rate improvement of chlorinated aromatic dye in non-ionic surfactant solutions.

PubMed

Ma, C W; Chu, W

2001-07-01

A typical insoluble chlorinated aromatic dye (CAD), disperse red (DR), was used to explore the reaction mechanism and kinetics of photodegradation in non-ionic surfactant solutions. The use of an additional hydrogen source and photosensitizer is also studied to improve the decay rates. The decay rate of dye in surfactants depends on the Km of surfactants and their ability to offering an effective hydrogen source. The photodegradation of CAD can be divided into three stages: the initial lag stage. the fast degradation stage and the final retardation stage. The lag stage will vanish and the decay rates of dye can be greatly improved by 2.5-3.6 times after adding an additional hydrogen source (NaBH4) or photosensitizer (acetone) to the surfactant micellar solution. However, the use of an additional hydrogen source or photosensitizer has dosage limitations in such applications. The photoreduction of DR is the main reaction mechanism, in which photodechlorination is observed first with the generation of HCI as the final product, then followed by photodecolorization by breaking the azo bond of the chromophore.

Effect of location and ionic interaction on photocatalytic activity of silver nanoparticles stabilized with polyDOPA

NASA Astrophysics Data System (ADS)

Cheon, Ja Young; Park, Won Ho

2018-05-01

PVA nanofibrous webs containing silver nanoparticles (Ag NPs) stabilized with poly(3,4-dihydroxyphenylalanine) (polyDOPA) were prepared using either the electrospinning or coating methods. The Ag NPs incorporated in the nanofibers were identified using SEM, TEM, TGA, and XRD. The catalytic reactions of the PVA nanofibrous webs containing the Ag NPs were compared using organic dyes under UV-vis spectroscopy. The location (inside and outside) of the Ag NPs in the nanofibers and the charge interaction between the dye and the Ag NPs had a significant effect on the catalytic reaction rate. When the Ag NPs existed in the outside of the nanofiber due to the coating method, the reaction rate was increased due to the presence of more contact sites with respect to the organic dye. Also, an electrostatic attraction between the organic dye and the pDA surrounding the Ag NPs increased the catalytic reaction rate. Therefore, it was demonstrated that the location and the surface charge of the Ag NPs in the nanofibrous web should be considered as crucial factors in terms of the catalytic performance of the Ag NPs for model dyes.

The construction, fouling and enzymatic cleaning of a textile dye surface.

PubMed

Onaizi, Sagheer A; He, Lizhong; Middelberg, Anton P J

2010-11-01

The enzymatic cleaning of a rubisco protein stain bound onto Surface Plasmon Resonance (SPR) biosensor chips having a dye-bound upper layer is investigated. This novel method allowed, for the first time, a detailed kinetic study of rubisco cleanability (defined as fraction of adsorbed protein removed from a surface) from dyed surfaces (mimicking fabrics) at different enzyme concentrations. Analysis of kinetic data using an established mathematical model able to decouple enzyme transfer and reaction processes [Onaizi, He, Middelberg, Chem. Eng. Sci. 64 (2008) 3868] revealed a striking effect of dyeing on enzymatic cleaning performance. Specifically, the absolute rate constants for enzyme transfer to and from a dye-bound rubisco stain were significantly higher than reported previously for un-dyed surfaces. These increased transfer rates resulted in higher surface cleanability. Higher enzyme mobility (i.e., higher enzyme adsorption and desorption rates) at the liquid-dye interface was observed, consistent with previous suggestions that enzyme surface mobility is likely correlated with overall enzyme cleaning performance. Our results show that reaction engineering models of enzymatic action at surfaces may provide insight able to guide the design of better stain-resistant surfaces, and may also guide efforts to improve cleaning formulations. Copyright 2010 Elsevier Inc. All rights reserved.

Criteria for selecting fluorescent dye tracers for soil hydrological applications using Uranine as an example

EPA Science Inventory

Calibrating and verifying 2-D and 3-D vadose zone flow and transport models requires detailed information on water and solute redistribution. Among the different water flow and mass transfer determination methods, staining tracers have the best spatial resolution allowing visuali...

Direct Methanol Fuel Cell (DMFC) Battery Replacement Program

DTIC Science & Technology

2013-01-29

selection of the Reynold’s number enables use of water for simulation of gas or liquid flow. Introduction of dye to the flow stream, with video...calibrated using a soap -film flow meter (Bubble-o-meter, Dublin, OH). Eleven Array system temperature regions were set as follows prior to start of...expected. The ar- ray flow proceeds down the columns: column effects would be more likely than row effects from a design of experiments perspective

Fragile X Mental Retardation Protein Restricts Small Dye Iontophoresis Entry into Central Neurons

PubMed Central

2017-01-01

Fragile X mental retardation protein (FMRP) loss causes Fragile X syndrome (FXS), a major disorder characterized by autism, intellectual disability, hyperactivity, and seizures. FMRP is both an RNA- and channel-binding regulator, with critical roles in neural circuit formation and function. However, it remains unclear how these FMRP activities relate to each other and how dysfunction in their absence underlies FXS neurological symptoms. In testing circuit level defects in the Drosophila FXS model, we discovered a completely unexpected and highly robust neuronal dye iontophoresis phenotype in the well mapped giant fiber (GF) circuit. Controlled dye injection into the GF interneuron results in a dramatic increase in dye uptake in neurons lacking FMRP. Transgenic wild-type FMRP reintroduction rescues the mutant defect, demonstrating a specific FMRP requirement. This phenotype affects only small dyes, but is independent of dye charge polarity. Surprisingly, the elevated dye iontophoresis persists in shaking B mutants that eliminate gap junctions and dye coupling among GF circuit neurons. We therefore used a wide range of manipulations to investigate the dye uptake defect, including timed injection series, pharmacology and ion replacement, and optogenetic activity studies. The results show that FMRP strongly limits the rate of dye entry via a cytosolic mechanism. This study reveals an unexpected new phenotype in a physical property of central neurons lacking FMRP that could underlie aspects of FXS disruption of neural function. SIGNIFICANCE STATEMENT FXS is a leading heritable cause of intellectual disability and autism spectrum disorders. Although researchers established the causal link with FMRP loss >;25 years ago, studies continue to reveal diverse FMRP functions. The Drosophila FXS model is key to discovering new FMRP roles, because of its genetic malleability and individually identified neuron maps. Taking advantage of a well characterized Drosophila neural circuit, we discovered that neurons lacking FMRP take up dramatically more current-injected small dye. After examining many neuronal properties, we determined that this dye defect is cytoplasmic and occurs due to a highly elevated dye iontophoresis rate. We also report several new factors affecting neuron dye uptake. Understanding how FMRP regulates iontophoresis should reveal new molecular factors underpinning FXS dysfunction. PMID:28887386

Assessment of gamete quality for the eastern oyster (Crassostrea virginica) by use of fluorescent dyes

USGS Publications Warehouse

Paniagua-Chavez, C. G.; Jenkins, J.; Segovia, M.; Tiersch, T.R.

2006-01-01

Evaluation of sperm motility is the single most widely used parameter to determine semen quality in mammals and aquatic species. While a good indicator for fresh sperm viability, post-thaw motility is not always effective at predicting fertilizing ability. Techniques using fluorescent dyes can assess functionality of mammalian sperm, but have not been widely applied in aquatic organisms. The eastern oyster Crassostrea virginica is an important mollusk in the United States, and cryopreservation protocols have been developed to preserve sperm and larvae to assist research and hatchery production. In this study, protocols were developed to assess sperm cell membrane integrity and mitochondrial function by flow cytometry and to assess viability of eggs by fluorescence microscopy. The fluorescent dyes SYBR 14 and propidium iodide (PI) (to assess membrane integrity) and rhodamine 123 (R123) (to assess mitochondrial membrane potential) were used to evaluate the quality of thawed oyster sperm previously cryopreserved with different cryoprotectant and thawing treatments. Membrane integrity results were correlated with motility of thawed sperm and mitochondrial membrane potential with fertilizing ability. Fluorescein diacetate (FDA) was used to assess cytotoxicity of cryoprotectant solutions and post-thaw damage to oyster eggs. The results indicated that membrane integrity (P = 0.004) and thawing treatments (P = 0.04), and mitochondrial membrane potential (P = 0.0015) were correlated with motility. Fertilizing ability was correlated with cryoprotectant treatments (P = 0.0258) and with mitochondrial membrane potential (P = 0.001). The dye FDA was useful in indicating structural integrity of fresh and thawed eggs. Exposure of eggs, without freezing, to dimethyl sulfoxide yielded higher percentages of stained eggs and fertilization rate than did exposure to propylene glycol (P = 0.002). Thawed eggs were not stained with FDA (<1%) and larvae were not produced. ?? 2006 Elsevier Inc. All rights reserved.

Development of a ROV Deployed Video Analysis Tool for Rapid Measurement of Submerged Oil/Gas Leaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savas, Omer

Expanded deep sea drilling around the globe makes it necessary to have readily available tools to quickly and accurately measure discharge rates from accidental submerged oil/gas leak jets for the first responders to deploy adequate resources for containment. We have developed and tested a field deployable video analysis software package which is able to provide in the field sufficiently accurate flow rate estimates for initial responders in accidental oil discharges in submarine operations. The essence of our approach is based on tracking coherent features at the interface in the near field of immiscible turbulent jets. The software package, UCB_Plume, ismore » ready to be used by the first responders for field implementation. We have tested the tool on submerged water and oil jets which are made visible using fluorescent dyes. We have been able to estimate the discharge rate within 20% accuracy. A high end WINDOWS laptop computer is suggested as the operating platform and a USB connected high speed, high resolution monochrome camera as the imaging device are sufficient for acquiring flow images under continuous unidirectional illumination and running the software in the field. Results are obtained over a matter of minutes.« less

Multiple sort flow cytometer

DOEpatents

Van den Engh, Ger; Esposito, Richard J.

1996-01-01

A flow cytometer utilizes multiple lasers for excitation and respective fluorescence of identified dyes bonded to specific cells or events to identify and verify multiple events to be sorted from a sheath flow and droplet stream. Once identified, verified and timed in the sheath flow, each event is independently tagged upon separation from the flow by an electrical charge of +60, +120, or +180 volts and passed through oppositely charged deflection plates with ground planes to yield a focused six way deflection of at least six events in a narrow plane.

Flow Cytometric Analysis of Presynaptic Nerve Terminals Isolated from Rats Subjected to Hypergravity

NASA Astrophysics Data System (ADS)

Borisova, Tatiana

2008-06-01

Flow cytometric studies revealed an insignificant decrease in cell size heterogeneity and cytoplasmic granularity of rat brain nerve terminals (synaptosomes) isolated from animals subjected to centrifuge-induced hypergravity as compared to control ones. The analysis of plasma membrane potential using the potentiometric optical dye rhodamine 6G showed a decrease in fluorescence intensity by 10 % at steady state level in hypergravity synaptosomes. To monitor synaptic vesicle acidification we used pH-sensitive fluorescent dye acridine orange and demonstrated a lower fluorescence intensity level at steady state (10%) after hypergravity as compared to controls. Thus, exposure to hypergravity resulted in depolarization of the synaptosomal plasma membrane and diminution in synaptic vesicle acidification that may be a cause leading to altered synaptic neurotransmission.

Dispersion of a Nanoliter Bolus in Microfluidic Co-Flow.

PubMed

Conway, A J; Saadi, W M; Sinatra, F L; Kowalski, G; Larson, D; Fiering, J

2014-03-01

Microfluidic systems enable reactions and assays on the scale of nanoliters. However, at this scale nonuniformities in sample delivery become significant. To determine the fundamental minimum sample volume required for a particular device, a detailed understanding of mass transport is required. Co-flowing laminar streams are widely used in many devices, but typically only in the steady-state. Because establishing the co-flow steady-state consumes excess sample volume and time, there is a benefit to operating devices in the transient state, which predominates as the volume of the co-flow reactor decreases. Analysis of the co-flow transient has been neglected thus far. In this work we describe the fabrication of a pneumatically controlled microfluidic injector constructed to inject a discrete 50nL bolus into one side of a two-stream co-flow reactor. Using dye for image analysis, injections were performed at a range of flow rates from 0.5-10μL/min, and for comparison we collected the co-flow steady-state data for this range. The results of the image analysis were also compared against theory and simulations for device validation. For evaluation, we established a metric that indicates how well the mass distribution in the bolus injection approximates steady-state co-flow. Using such analysis, transient-state injections can approximate steady-state conditions within predefined errors, allowing straight forward measurements to be performed with reduced reagent consumption.

Near-IR squaraine dye–loaded gated periodic mesoporous organosilica for photo-oxidation of phenol in a continuous-flow device

PubMed Central

Borah, Parijat; Sreejith, Sivaramapanicker; Anees, Palapuravan; Menon, Nishanth Venugopal; Kang, Yuejun; Ajayaghosh, Ayyappanpillai; Zhao, Yanli

2015-01-01

Periodic mesoporous organosilica (PMO) has been widely used for the fabrication of a variety of catalytically active materials. We report the preparation of novel photo-responsive PMO with azobenzene-gated pores. Upon activation, the azobenzene gate undergoes trans-cis isomerization, which allows an unsymmetrical near-infrared squaraine dye (Sq) to enter into the pores. The gate closure by cis-trans isomerization of the azobenzene unit leads to the safe loading of the monomeric dye inside the pores. The dye-loaded and azobenzene-gated PMO (Sq-azo@PMO) exhibits excellent generation of reactive oxygen species upon excitation at 664 nm, which can be effectively used for the oxidation of phenol into benzoquinone in aqueous solution. Furthermore, Sq-azo@PMO as the catalyst was placed inside a custom-built, continuous-flow device to carry out the photo-oxidation of phenol to benzoquinone in the presence of 664-nm light. By using the device, about 23% production of benzoquinone with 100% selectivity was achieved. The current research presents a prototype of transforming heterogeneous catalysts toward practical use. PMID:26601266

Characterization of a BODIPY Dye as an Active Species for Redox Flow Batteries.

PubMed

Kosswattaarachchi, Anjula M; Friedman, Alan E; Cook, Timothy R

2016-12-08

An all-organic redox flow battery (RFB) employing a fluorescent boron-dipyrromethene (BODIPY) dye (PM567) was investigated. In a RFB, the stability of the electrolyte in all charged states is critically linked to coulombic efficiency. To evaluate stability, bulk electrolysis and cyclic voltammetry (CV) experiments were performed. Oxidized and reduced, PM567 does not remain intact; however, the products of bulk electrolysis evolve over time to show stable redox behavior, making the dye a precursor for the active species of an RFB. A theoretical cell potential of 2.32 V was predicted from CV experiments with a working discharge voltage of approximately 1.6 V in a static test cell. Mass spectrometry was used to identify the products of bulk electrolysis. Related experiments were carried out using ferrocene and cobaltocenium hexafluorophosphate as redox-stable benchmarks to further explain the stability results. The coulombic efficiency of a model cell using PM567 as a precursor for charge carriers stabilized around 73 %. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An evaluation of the hydrologic relevance of lateral flow in snow at hillslope and catchment scales

Treesearch

David Eiriksson; Michael Whitson; Charles H. Luce; Hans Peter Marshall; John Bradford; Shawn G. Benner; Thomas Black; Hank Hetrick; James P. McNamara

2013-01-01

Lateral downslope flow in snow during snowmelt and rain-on-snow (ROS) events is a well-known phenomenon, yet its relevance to water redistribution at hillslope and catchment scales is not well understood. We used dye tracers, geophysical methods, and hydrometric measurements to describe the snow properties that promote lateral flow, assess the relative velocities of...

Decolorization and Detoxification of Textile Dyes with a Laccase from Trametes hirsuta

PubMed Central

Abadulla, Elias; Tzanov, Tzanko; Costa, Silgia; Robra, Karl-Heinz; Cavaco-Paulo, Artur; Gübitz, Georg M.

2000-01-01

Trametes hirsuta and a purified laccase from this organism were able to degrade triarylmethane, indigoid, azo, and anthraquinonic dyes. Initial decolorization velocities depended on the substituents on the phenolic rings of the dyes. Immobilization of the T. hirsuta laccase on alumina enhanced the thermal stabilities of the enzyme and its tolerance against some enzyme inhibitors, such as halides, copper chelators, and dyeing additives. The laccase lost 50% of its activity at 50 mM NaCl while the 50% inhibitory concentration (IC50) of the immobilized enzyme was 85 mM. Treatment of dyes with the immobilized laccase reduced their toxicities (based on the oxygen consumption rate of Pseudomonas putida) by up to 80% (anthraquinonic dyes). Textile effluents decolorized with T. hirsuta or the laccase were used for dyeing. Metabolites and/or enzyme protein strongly interacted with the dyeing process indicated by lower staining levels (K/S) values than obtained with a blank using water. However, when the effluents were decolorized with immobilized laccase, they could be used for dyeing and acceptable color differences (ΔE*) below 1.1 were measured for most dyes. PMID:10919791

A multilevel reuse system with source separation process for printing and dyeing wastewater treatment: A case study.

PubMed

Wang, Rui; Jin, Xin; Wang, Ziyuan; Gu, Wantao; Wei, Zhechao; Huang, Yuanjie; Qiu, Zhuang; Jin, Pengkang

2018-01-01

This paper proposes a new system of multilevel reuse with source separation in printing and dyeing wastewater (PDWW) treatment in order to dramatically improve the water reuse rate to 35%. By analysing the characteristics of the sources and concentrations of pollutants produced in different printing and dyeing processes, special, highly, and less contaminated wastewaters (SCW, HCW, and LCW, respectively) were collected and treated separately. Specially, a large quantity of LCW was sequentially reused at multiple levels to meet the water quality requirements for different production processes. Based on this concept, a multilevel reuse system with a source separation process was established in a typical printing and dyeing enterprise. The water reuse rate increased dramatically to 62%, and the reclaimed water was reused in different printing and dyeing processes based on the water quality. This study provides promising leads in water management for wastewater reclamation. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of the textile industry dye bath additive EDTMPA on colour removal characteristics by ozone oxidation.

PubMed

Olmez, T; Kabdaşli, I; Tünay, O

2007-01-01

In this study, the effects of the phosphonic acid based sequestering agent EDTMPA used in the textile dye baths on colour and organic matter removal by ozone oxidation was experimentally investigated. Procion Navy HEXL dyestuff that has been commonly used for the reactive dyeing of cellulose fibers was selected as the model component. The organic matter oxidation by ozone was determined to obey the pseudo-first order kinetics as they are treated singly or in combination. COD removal rates obtained from pseudo-first order reaction kinetics showed that oxidation of Navy HEXL alone (0.0947 L/min) was faster than that of EDTMPA (0.0171 L/min) and EDTMPA with dye (0.0155 L/min) at pH 3.0. It was also found that reaction rates of single EDTMPA removal and EDTMPA and dye mixture removal increased as the reaction pH was increased from 3.0 to 10.5.

Biosorption of Azo dyes by spent Rhizopus arrhizus biomass

NASA Astrophysics Data System (ADS)

Salvi, Neeta A.; Chattopadhyay, S.

2017-10-01

In the present study, spent Rhizopus arrhizus biomass was used for the removal of six azo dyes from aqueous solutions. The dye removal capacity of the biomass was evaluated by conducting batch tests as a function of contact time, biomass dosage, pH and initial dye concentrations. The pseudo-second-order kinetic model fitted well with the experimental data with correlation coefficients greater than 0.999, suggesting that chemisorptions might be the rate limiting step. The equilibrium sorption data showed good fit to the Langmuir isotherm model. Among the six dyes tested, the maximum monolayer adsorption capacity for fast red A and metanil yellow was found to be 108.8 and 128.5 mg/g, respectively. These encouraging results suggest that dead Rhizopus arrhizus biomass could be a potential biomaterial for the removal of azo dyes from aqueous dye solution.

Traveltime and dispersion in the Shenandoah River and its tributaries, Waynesboro, Virginia, to Harpers Ferry, West Virginia

USGS Publications Warehouse

Taylor, K.R.; James, R.W.; Helinsky, B.M.

1986-01-01

Two traveltime and dispersion measurements using rhodamin dye were conducted on a 178-mile reach of the Shenandoah River between Waynesboro, Virginia, and Harpers Ferry, West Virginia. The flows during the two measurements were at approximately the 85% and 45% flow durations. The two sets of data were used to develop a generalized procedure for predicting traveltimes and downstream concentrations resulting from spillage of water soluble substances at any point along the river reach studied. The procedure can be used to calculate traveltime and concentration data for almost any spillage that occurs during relatively steady flow between a 40% to 95% flow duration. Based on an analogy between the general shape of a time concentration curve and a scalene triangle, the procedures can be used on long river reaches to approximate the conservative time concentration curve for instantaneous spills of contaminants. The triangular approximation technique can be combined with a superposition technique to predict the approximate, conservative time concentration curve for constant rate and variable rate injections of contaminants. The procedure was applied to a hypothetical situation in which 5,000 pounds of contaminants is spilled instantaneously at Island Ford, Virginia. The times required for the leading edge, the peak concentration, and the trailing edge of the contaminant cloud to reach the water intake at Front Royal, Virginia (85 miles downstream), are 234,280, and 340 hrs, respectively, for a flow at an 80% flow duration. The conservative peak concentration would be approximately 940 micrograms/L at Front Royal. The procedures developed cannot be depended upon when a significant hydraulic wave or other unsteady flow condition exists in the flow system or when the spilled material floats or is immiscible in water. (Author 's abstract)

Optically based quantification of absolute cerebral metabolic rate of oxygen (CMRO2) with high spatial resolution in rodents

NASA Astrophysics Data System (ADS)

Yaseen, Mohammad A.; Srinivasan, Vivek J.; Sakadžić, Sava; Vinogradov, Sergei A.; Boas, David A.

2010-02-01

Measuring oxygen delivery in brain tissue is important for identifying the pathophysiological changes associated with brain injury and various diseases such as cancer, stroke, and Alzheimer's disease. We have developed a multi-modal imaging system for minimally invasive measurement of cerebral oxygenation and blood flow in small animals with high spatial resolution. The system allows for simultaneous measurement of blood flow using Fourier-domain optical coherence tomography, and oxygen partial pressure (pO2) using either confocal or multiphoton phosphorescence lifetime imaging with exogenous porphyrin-based dyes sensitive to dissolved oxygen. Here we present the changes in pO2 and blood flow in superficial cortical vessels of Sprague Dawley rats in response to conditions such as hypoxia, hyperoxia, and functional stimulation. pO2 measurements display considerable heterogeneity over distances that cannot be resolved with more widely used oxygen-monitoring techniques such as BOLD-fMRI. Large increases in blood flow are observed in response to functional stimulation and hypoxia. Our system allows for quantification of cerebral metabolic rate of oxygen (CMRO2) with high spatial resolution, providing a better understanding of metabolic dynamics during functional stimulation and under various neuropathologies. Ultimately, better insight into the underlying mechanisms of neuropathologies will facilitate the development of improved therapeutic strategies to minimize damage to brain tissue.

[Adsorption of the TiO2 @ yeast composite microspheres for adsorbing Fluorescent Whitening Agent-VBL in fixed bed].

PubMed

Wu, Fei; Zhang, Kai-Qiang; Bai, Bo; Wang, Hong-Lun; Suo, You-Rui

2015-02-01

In this work, the adsorption potential of TiO2@ yeast composite microspheres to remove Fluorescent Whitening Agent-VBL (FWA-VBL) from aqueous solution was investigated using fixed-bed adsorption column. The effects of pH(2.0-8.0), bed height (1-3 cm), inlet concentration (20-80 mg x L(-1)) and feed flow rate (5-11 mL x min(-1)) on the breakthrough characteristics of the adsorption system were determined. The results showed that the highest bed capacity of 223.80 mg x g(-1) was obtained under the condition of pH 2.0, 80 mg x L(-1) inlet dye concentration, 1.0 cm bed height and 5 mL x min(-1) flow rate. The adsorption data were fitted to three well-established fixed-bed adsorption models, namely, BDST model, Thomas model and Yoon-Nelson model. The results fitted well to the three models with coefficients of correlation R2 > 0.980 in different conditions. The TiO2 @ yeast composite microspheres have desired regeneration ability and could be reused for four times.

Evidence for significantly enhancing reduction of Azo dyes in Escherichia coli by expressed cytoplasmic Azoreductase (AzoA) of Enterococcus faecalis.

PubMed

Feng, J; Heinze, T M; Xu, H; Cerniglia, C E; Chen, H

2010-05-01

Although cytoplasmic azoreductases have been purified and characterized from various bacteria, little evidence demonstrating that these azoreductases are directly involved in azo dye reduction in vivo is known. In order to evaluate the contribution of the enzyme to azo dye reduction in vivo, experiments were conducted to determine the effect of a recombinant cytoplasmic azoreductase (AzoA) from Enterococcus faecalis expressed in Escherichia coli on the rate of metabolism of Methyl Red, Ponceau BS and Orange II. The intact cells that contained IPTG induced AzoA had a higher rate of dye reduction with increases of 2 (Methyl Red), 4 (Ponceau BS) and 2.6 (Orange II)-fold compared to noninduced cells, respectively. Metabolites of Methyl Red isolated from induced cultures were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid through liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) analyses. In conclusion, our data demonstrate that AzoA from Ent. faecalis is capable of increasing the reduction of azo dyes in intact E. coli cells and that cytoplasmic azoreductase is involved in bacterial dye degradation in vivo.

Evidence for Significantly Enhancing Reduction of Azo Dyes in Escherichia coli by Expressed Cytoplasmic Azoreductase (AzoA) of Enterococcus faecalis

PubMed Central

Feng, Jinhui; Heinze, Thomas M.; Xu, Haiyan; Cerniglia, Carl E.; Chen, Huizhong

2018-01-01

Although cytoplasmic azoreductases have been purified and characterized from various bacteria, little evidence demonstrating that these azoreductases are directly involved in azo dye reduction in vivo is known. In order to evaluate the contribution of the enzyme to azo dye reduction in vivo, experiments were conducted to determine the effect of a recombinant cytoplasmic azoreductase (AzoA) from Enterococcus faecalis expressed in Escherichia coli on the rate of metabolism of Methyl Red, Ponceau BS and Orange II. The intact cells that contained IPTG induced AzoA had a higher rate of dye reduction with increases of 2 (Methyl Red), 4 (Ponceau BS) and 2.6 (Orange II)-fold compared to noninduced cells, respectively. Metabolites of Methyl Red isolated from induced cultures were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid through liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) analyses. In conclusion, our data demonstrate that AzoA from Ent. faecalis is capable of increasing the reduction of azo dyes in intact E. coli cells and that cytoplasmic azoreductase is involved in bacterial dye degradation in vivo. PMID:19663804

Effects of a Red Marker Dye on Aedes and Culex Larvae: Are There Implications for Operational Mosquito Control?

PubMed

Unlu, Isik; Leisnham, Paul T; Williams, Gregory M; Klingler, Kim; Dow, Garrett W; Kirchoff, Nicole; Jin, Sophie; Delisi, Nicholas; Montenegro, Katherine; Faraji, Ary

2015-12-01

Marker dyes are often mixed with liquid insecticide formulations prior to field applications to accurately determine the characteristics and penetration of droplets into targeted habitats. We have been using FD&C Red 40 Granular DM food dye at the rate of 20 g/liter in liquid solutions of Bacillus thuringiensis israelensis (Bti) for area-wide larvicide applications against the Asian tiger mosquito, Aedes albopictus. The Bti and dye mix ratio has been recommended by pesticide manufacturers for testing under operational conditions, but no data exist on the effects of the dye itself on mosquito larvae. We tested the effects of the FD&C Red 40 food dye in laboratory bioassays against different strains of Ae. albopictus (New Jersey and Maryland) and Culex pipiens pipiens (Utah) at rates of 0.039 to 80.0 g/liter. We also conducted field application trials to measure dye concentrations up to 100 m downwind when mixed and applied according to manufacturer instructions. In laboratory bioassays, we found that mean survival in cups with dye were significantly different from the controls beginning at 10.0 g/liter for New Jersey Ae. albopictus and at 20.0 g/liter for Maryland Ae. albopictus and Utah Cx. p. pipiens. In field application trials, we recorded a maximum volume density of 1,152.8 nl/cm(2) and calculated the maximum concentration of dye at 9.09 × 10(-3) g/liter. Our results showed that although we detected greater effects of dye on Ae. albopictus in New Jersey experiments than Ae. albopictus in Maryland and Cx. p. pipiens from Utah, concentrations of the dye during operational applications were at least 1,100 times below concentrations that exhibited toxic effects for either species in the laboratory, suggesting that the dye will not interfere with accuracy of field bioassays. Our results conclusively demonstrate that the addition of the FD&C Red 40 marker dye does not alter the efficacy of the pesticide formulation by skewing results, but rather provides a valuable addition to accurately determine pesticide penetration and spectrum by discriminating between intended pesticide and other potential pollutants.

Feasibility study: Atmospheric general circulation experiment, volume 1

NASA Technical Reports Server (NTRS)

Homsey, R. J. (Editor)

1981-01-01

The atmospheric general circulation experiment (AGCE) uses a rotating fluid flow cell assembly. The key technical areas affecting the feasibility of the design and operation of the AGCE are investigated. The areas investigated include materials for the flow cell assembly, thermal design, high voltage power supply design, effective retrieval and handling of experiment data and apparatus configuration. Several materials, DMSO and m-tolunitrile, were selected as candidate fluids for the flow cell principally for their high dielectric constant which permits the high voltage power supply design to be held to 15 kV and still simulate terrestrial gravity. Achievement of a low dissipation factor in the fluid to minimize internal heating from the applied electrical field depends strongly on purification and handling procedures. The use of sapphire as the outer hemisphere for the flow cell provides excellent viewing conditions without a significant impact on attaining the desired thermal gradients. Birefringent effects from sapphire can be held to acceptably low limits. Visualization of flow fluid is achieved through the motion of a dot matrix formed by photochromic dyes. Two dyes found compatible with the candidate fluids are spiropyran and triarylmethane. The observation of the dot motion is accomplished using a flying spot scanner.

Aerobic Biodegradation Characteristic of Different Water-Soluble Azo Dyes.

PubMed

Sheng, Shixiong; Liu, Bo; Hou, Xiangyu; Wu, Bing; Yao, Fang; Ding, Xinchun; Huang, Lin

2017-12-26

This study investigated the biodegradation performance and characteristics of Sudan I and Acid Orange 7 (AO7) to improve the biological dye removal efficiency in wastewater and optimize the treatment process. The dyes with different water-solubility and similar molecular structure were biologically treated under aerobic condition in parallel continuous-flow mixed stirred reactors. The biophase analysis using microscopic examination suggested that the removal process of the two azo dyes is different. Removal of Sudan I was through biosorption, since it easily assembled and adsorbed on the surface of zoogloea due to its insolubility, while AO7 was biodegraded incompletely and bioconverted, the AO7 molecule was decomposed to benzene series and inorganic ions, since it could reach the interior area of zoogloea due to the low oxidation-reduction potential conditions and corresponding anaerobic microorganisms. The transformation of NH₃-N, SO₄ 2- together with the presence of tryptophan-like components confirm that AO7 can be decomposed to non-toxic products in an aerobic bioreactor. This study provides a theoretical basis for the use of biosorption or biodegradation mechanisms for the treatment of different azo dyes in wastewater.

Pollination of pima pineapple cactus (Coryphantha sheeri var. robustispina): does pollen flow limit abundance of this endangered species?

Treesearch

Christopher J. McDonald; Guy R. McPherson

2005-01-01

Pima pineapple cactus (PPC) (Coryphantha sheeri var. robustispina), a federally listed endangered species, occurs throughout southeastern Arizona and has relatively low population densities. To determine whether pollination limits reproduction of PPC we used florescent dye to quantify pollen flow between individuals in a PPC...

Biomat Flow: From Field Experiments with Dyes to Pore-Scale Modeling of Transport Properties and Flow Models

EPA Science Inventory

Recent studies highlight the important role that the upper litter layer in forest soils (biomat) plays in hillslope and catchment runoff generation. This biomat layer is a very loose material with high porosity and organic content. Direct sampling is usually problematic due to li...

Measurement of Interfacial Profiles of Wavy Film Flow on Inclined Wall

NASA Astrophysics Data System (ADS)

Rosli, N.; Amagai, K.

2016-02-01

Falling liquid films on inclined wall present in many industrial processes such as in food processing, seawater desalination and electronic devices manufacturing industries. In order to ensure an optimal efficiency of the operation in these industries, a fundamental study on the interfacial flow profiles of the liquid film is of great importance. However, it is generally difficult to experimentally predict the interfacial profiles of liquid film flow on inclined wall due to the instable wavy flow that usually formed on the liquid film surface. In this paper, the liquid film surface velocity was measured by using a non-intrusive technique called as photochromic dye marking method. This technique utilizes the color change of liquid containing the photochromic dye when exposed to the UV light source. The movement of liquid film surface marked by the UV light was analyzed together with the wave passing over the liquid. As a result, the liquid film surface was found to slightly shrink its gradual movement when approached by the wave before gradually move again after the intersection with the wave.

A microfluidic needle for sampling and delivery of chemical signals by segmented flows

NASA Astrophysics Data System (ADS)

Feng, Shilun; Liu, Guozhen; Jiang, Lianmei; Zhu, Yonggang; Goldys, Ewa M.; Inglis, David W.

2017-10-01

We have developed a microfluidic needle-like device that can extract and deliver nanoliter samples. The device consists of a T-junction to form segmented flows, parallel channels to and from the needle tip, and seven hydrophilic capillaries at the tip that form a phase-extraction region. The main microchannel is hydrophobic and carries segmented flows of water-in-oil. The hydrophilic capillaries transport the aqueous phase with a nearly zero pressure gradient but require a pressure gradient of 19 kPa for mineral oil to invade and flow through. Using this device, we demonstrate the delivery of nanoliter droplets and demonstrate sampling through the formation of droplets at the tip of our device. During sampling, we recorded the fluorescence intensities of the droplets formed at the tip while varying the concentration of dye outside the tip. We measured a chemical signal response time of approximately 3 s. The linear relationship between the recorded fluorescence intensity of samples and the external dye concentration (10-40 μg/ml) indicates that this device is capable of performing quantitative, real-time measurements of rapidly varying chemical signals.

Enhanced model-based design of a high-throughput three dimensional micromixer driven by alternating-current electrothermal flow.

PubMed

Wu, Yupan; Ren, Yukun; Jiang, Hongyuan

2017-01-01

We propose a 3D microfluidic mixer based on the alternating current electrothermal (ACET) flow. The ACET vortex is produced by 3D electrodes embedded in the sidewall of the microchannel and is used to stir the fluidic sample throughout the entire channel depth. An optimized geometrical structure of the proposed 3D micromixer device is obtained based on the enhanced theoretical model of ACET flow and natural convection. We quantitatively analyze the flow field driven by the ACET, and a pattern of electrothermal microvortex is visualized by the micro-particle imaging velocimetry. Then, the mixing experiment is conducted using dye solutions with varying solution conductivities. Mixing efficiency can exceed 90% for electrolytes with 0.2 S/m (1 S/m) when the flow rate is 0.364 μL/min (0.728 μL/min) and the imposed peak-to-peak voltage is 52.5 V (35 V). A critical analysis of our micromixer in comparison with different mixer designs using a comparative mixing index is also performed. The ACET micromixer embedded with sidewall 3D electrodes can achieve a highly effective mixing performance and can generate high throughput in the continuous-flow condition. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative investigation of resolution increase of free-flow electrophoresis via simple interval sample injection and separation.

PubMed

Shao, Jing; Fan, Liu-Yin; Cao, Cheng-Xi; Huang, Xian-Qing; Xu, Yu-Quan

2012-07-01

Interval free-flow zone electrophoresis (FFZE) has been used to suppress sample band broadening greatly hindering the development of free-flow electrophoresis (FFE). However, there has been still no quantitative study on the resolution increase of interval FFZE. Herein, we tried to make a comparison between bandwidths in interval FFZE and continuous one. A commercial dye with methyl green and crystal violet was well chosen to show the bandwidth. The comparative experiments were conducted under the same sample loading of the model dye (viz. 3.49, 1.75, 1.17, and 0.88 mg/h), the same running time (viz. 5, 10, 15, and 20 min), and the same flux ratio between sample and background buffer (= 10.64 × 10⁻³). Under the given conditions, the experiments demonstrated that (i) the band broadening was evidently caused by hydrodynamic factor in continuous mode, and (ii) the interval mode could clearly eliminate the hydrodynamic broadening existing in continuous mode, greatly increasing the resolution of dye separation. Finally, the interval FFZE was successfully used for the complete separation of two-model antibiotics (herein pyoluteorin and phenazine-1-carboxylic acid coexisting in fermentation broth of a new strain Pseudomonas aeruginosa M18), demonstrating the feasibility of interval FFZE mode for separation of biomolecules. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fast simultaneous assessment of renal and liver function using polymethine dyes in animal models of chronic and acute organ injury.

PubMed

Press, A T; Butans, M J; Haider, T P; Weber, C; Neugebauer, S; Kiehntopf, M; Schubert, U S; Clemens, M G; Bauer, M; Kortgen, A

2017-11-13

Simultaneous assessment of excretory liver and kidney function is still an unmet need in experimental stress models as well as in critical care. The aim of the study was to characterize two polymethine-dyes potentially suitable for this purpose in vivo. Plasma disappearance rate and elimination measurements of simultaneously injected fluorescent dyes DY-780 (hepato-biliary elimination) and DY-654(renal elimination) were conducted using catheter techniques and intravital microscopy in animals subjected to different organ injuries, i.e. polymicrobial sepsis by peritoneal contamination and infection, ischemia-reperfusion-injury and glycerol-induced acute kidney-injury. DY-780 and DY-654 showed organ specific and determined elimination routes in both healthy and diseased animals. They can be measured simultaneously using near-infrared imaging and spectrophotometry. Plasma-disappearance rates of DY-780 and DY-654 are superior to conventional biomarkers in indicating hepatic or kidney dysfunction in different animal models. Greatest impact on liver function was found in animals with polymicrobial sepsis whereas glomerular damage due to glycerol-induced kidney-injury had strongest impact on DY-654 elimination. We therefore conclude that hepatic elimination and renal filtration can be assessed in rodents measuring plasma-disappearance rates of both dyes. Further, assessment of organ dysfunction by polymethine dyes correlates with, but outperforms conventional biomarkers regarding sensitivity and the option of spatial resolution if biophotonic strategies are applied. Polymethine-dye clearance thereby allows sensitive point-of-care assessment of both organ functions simultaneously.

Color Degradation of Textiles with Natural Dyes and of Blue Scale Standards Exposed to White LED Lamps:Evaluation of White LED Lamps for Effectiveness as Museum Lighting

NASA Astrophysics Data System (ADS)

Ishii, Mie; Moriyama, Takayoshi; Toda, Masahiro; Kohmoto, Kohtaro; Saito, Masako

White light-emitting diodes (LED) are well suited for museum lighting because they emit neither UV nor IR radiation, which damage artifacts. The color degradation of natural dyes and blue scale standards (JIS L 0841) by white LED lamps are examined, and the performance of white LED lamps for museum lighting is evaluated. Blue scale standard grades 1-6 and silk fabrics dyed with 22 types of natural dyes classified as mid to highly responsive in a CIE technical report (CIE157:2004) were exposed to five types of white LED lamps using different luminescence methods and color temperatures. Color changes were measured at each 15000 lx·hr (500 lx at fabric surface × 300 hr) interval ten times. The accumulated exposure totaled 150000 lx·hr. The data on conventional white LED lamps and previously reported white fluorescent (W) and museum fluorescent (NU) lamps was evaluated. All the white LED lamps showed lower fading rates compared with a W lamp on a blue scale grade 1. The fading rate of natural dyes in total was the same between an NU lamp (3000 K) and a white LED lamp (2869 K). However, yellow natural dyes showed higher fading rates with the white LED lamp. This tendency is due to the high power characteristic of the LED lamp around 400-500 nm, which possibly contributes to the photo-fading action on the dyes. The most faded yellow dyes were Ukon (Curcuma longa L.) and Kihada (Phellodendron amurense Rupr.), and these are frequently used in historic artifacts such as kimono, wood-block prints, and scrolls. From a conservation point of view, we need to continue research on white LED lamps for use in museum lighting.

Predicting signatures of anisotropic resonance energy transfer in dye-functionalized nanoparticles† †Electronic supplementary information (ESI) available: Molecular structure and TDM of Cy3B. Table of dielectric constants. Dielectric mismatch at the surface of the NP: excitonic states and TEF of the NP. Additional data in RET rates calculation. Experimental absorption and PL spectra of the dye and the NP. Master equations and time-dependent populations. Steady-state rates and spectra. Blocking and back-transfer effects. Octahedral tessellation. Average RET rates. Details on Fig. 5 inset of the main text. Poisson distribution of the number of dyes per NP. See DOI: 10.1039/c6ra22433d Click here for additional data file.

PubMed Central

Corni, Stefano; Delgado, Alain; Bertoni, Andrea; Goldoni, Guido

2016-01-01

Resonance energy transfer (RET) is an inherently anisotropic process. Even the simplest, well-known Förster theory, based on the transition dipole–dipole coupling, implicitly incorporates the anisotropic character of RET. In this theoretical work, we study possible signatures of the fundamental anisotropic character of RET in hybrid nanomaterials composed of a semiconductor nanoparticle (NP) decorated with molecular dyes. In particular, by means of a realistic kinetic model, we show that the analysis of the dye photoluminescence difference for orthogonal input polarizations reveals the anisotropic character of the dye–NP RET which arises from the intrinsic anisotropy of the NP lattice. In a prototypical core/shell wurtzite CdSe/ZnS NP functionalized with cyanine dyes (Cy3B), this difference is predicted to be as large as 75% and it is strongly dependent in amplitude and sign on the dye–NP distance. We account for all the possible RET processes within the system, together with competing decay pathways in the separate segments. In addition, we show that the anisotropic signature of RET is persistent up to a large number of dyes per NP. PMID:28066545

Counterion-enhanced cyanine dye loading into lipid nano-droplets for single-particle tracking in zebrafish.

PubMed

Kilin, Vasyl N; Anton, Halina; Anton, Nicolas; Steed, Emily; Vermot, Julien; Vandamme, Thierry F; Mely, Yves; Klymchenko, Andrey S

2014-06-01

Superior brightness of fluorescent nanoparticles places them far ahead of the classical fluorescent dyes in the field of biological imaging. However, for in vivo applications, inorganic nanoparticles, such as quantum dots, are limited due to the lack of biodegradability. Nano-emulsions encapsulating high concentrations of organic dyes are an attractive alternative, but classical fluorescent dyes are inconvenient due to their poor solubility in the oil and their tendency to form non-fluorescent aggregates. This problem was solved here for a cationic cyanine dye (DiI) by substituting its perchlorate counterion for a bulky and hydrophobic tetraphenylborate. This new dye salt, due to its exceptional oil solubility, could be loaded at 8 wt% concentration into nano-droplets of controlled size in the range 30-90 nm. Our 90 nm droplets, which contained >10,000 cyanine molecules, were >100-fold brighter than quantum dots. This extreme brightness allowed, for the first time, single-particle tracking in the blood flow of live zebrafish embryo, revealing both the slow and fast phases of the cardiac cycle. These nano-droplets showed minimal cytotoxicity in cell culture and in the zebrafish embryo. The concept of counterion-based dye loading provides a new effective route to ultra-bright lipid nanoparticles, which enables tracking single particles in live animals, a new dimension of in vivo imaging. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of coloring efficacy of lac dye in comminuted meat product.

PubMed

Divya; Singh, R P; Baboo, B; Prasad, K M

2011-06-01

Effect of incorporation of graded levels (4, 6, 8, 10, 25 ppm) of lac dye on coloring efficacy and possible use of this natural color in processed meat products was studied. Inclusion of lac dye at different concentrations did not affect the pH significantly whereas a linear increase in the Lovibond red color unit of chicken nuggets was noted with raising the level of lac dye from 4 to 10 ppm. The sensory rating for color was highest at addition level of 25 ppm of lac dye and it was comparable to color score of the product containing 200 ppm sodium nitrite. Lac dye inclusion in nuggets at all concentrations studied had better antimicrobial properties as compared to 200 ppm sodium nitrite. It was concluded that lac dye from 10 to 25 ppm could be incorporated in comminuted meat products as a natural colorant with antimicrobial action.

Leaching of Br-, metolachlor, alachlor, atrazine, deethylatrazine and deisopropylatrazine in clayey vadoze zone: a field scale experiment in north-east Greece.

PubMed

Vryzas, Zisis; Papadakis, Emmanuel Nikolaos; Papadopoulou-Mourkidou, E

2012-04-15

An extensive four-year research program has been carried out to explore and acquire knowledge about the fundamental agricultural practices and processes affecting the mobility and bioavailability of pesticides in soils under semi-arid Mediterranean conditions. Pesticide leaching was studied under field conditions at five different depths using suction cups. Monitoring of metolachlor, alachlor, atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), and bromide ions in soil water, as well as dye patterns made apparent the significant role of preferential flow to the mobility of the studied compounds. Irrespective to their adsorption capacities and degradation rates, atrazine, metolachlor and bromide ions were simultaneously detected to 160 cm depth. Following 40 mm irrigation, just after their application, both alachlor and atrazine were leached to 160 cm depth within 18 h, giving maximum concentrations of 211 and 199 μg L(-1), respectively. Metolachlor was also detected in all depth when its application was followed by a rainfall event (50 mm) two weeks after its application. The greatest concentrations of atrazine, alachlor and metolachlor in soil water were 1795, 1166 and 845 μg L(-1), respectively. The greatest concentrations of atrazine's degradation products (both DEA and DIA) appeared later in the season compared to the parent compound. Metolachlor exhibited the greatest persistence with concentrations up to 10 μg L(-1) appearing in soil water 18 months after its application. Brilliant blue application followed by 40 mm irrigation clearly depict multi-branching network of preferential flow paths allowing the fast flow of the dye down to 150 cm within 24 h. This network was created by soil cracks caused by shrinking of dry soils, earthworms and plant roots. Chromatographic flow of the stained soil solution was evident only in the upper 10-15 cm of soil. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessment of the Dyeing Properties of the Pigments Produced by Talaromyces spp.

PubMed Central

Oliveira, Jorge; Sousa-Gallagher, Maria; Montañez, Julio Cesar

2017-01-01

The high production yields of pigments by Talaromyces spp. and their high thermal stability have implied that industrial application interests may emerge in the food and textile industries, as they both involve subjecting the colourants to high temperatures. The present study aimed to assess the potential application of the pigments produced by Talaromyces spp. in the textile area by studying their dyeing properties. Dyeing studies were performed on wool. The dyeing process consisted of three stages: scouring, mordanting, and dyeing. Two different mordants (alum, A; ferric chloride, F) were tested at different concentrations on fabric weight (A: 5, 10, 15%; F: 10, 20, 30%). The mordanting process had a significant effect on the final colour of the dyed fabrics obtained. The values of dyeing rate constant (k), half-time of dyeing (t1/2), and sorption kinetics behaviour were evaluated and discussed. The obtained results showed that pigments produced by Talaromyces spp. could serve as a source for the natural dyeing of wool textiles. PMID:29371555

Effect of TiO2 nanoparticles on some photophysical characteristics of ketocyanine dyes.

PubMed

Thipperudrappa, Javuku; Raghavendra, U P; Basanagouda, Mahantesha

2017-11-01

The effect of titanium dioxide (TiO 2 ) nanoparticles (NPs) on photophysical characteristics of 2,5-di[(E)-1-(4-dimethylaminophenyl) methylidine]-1-cyclopentanone (2,5-DMAPMC) and 2,5-di[(E)-1-(4-diethylaminophenyl)methylidine]-1-cyclopentanone (2,5-DEAPMC) ketocyanine dyes has been studied using absorption, steady-state and time-resolved fluorescence spectroscopy. The magnitudes of association constants determined based on modified absorption spectrum of dyes due to the presence of TiO 2 NPs indicate the interaction of TiO 2 NPs with dye molecules. The quenching of fluorescence intensity of dyes by TiO 2 NPs is observed and it follows linear Stern-Volmer (S-V) equation. The magnitude of quenching rate parameter suggests the involvement of static quenching mechanism. The involvement of electron transfer process in reducing fluorescence intensity of dyes has been discussed. Also, varying influence of TiO 2 NPs on two dyes is explained based on the presence of different alkyl substituent in two dyes. Copyright © 2017 John Wiley & Sons, Ltd.

Characterization of Nanoparticles by Capillary Electrophoresis and Trapping of Nanoparticles in Microfluidics Device

DTIC Science & Technology

2009-08-01

tubular mode driven by electroosmotic flow and the inherent electrophoretic mobility of the analytes under the influence of an applied electric field...could be due to unlabeled beads. Figure 3 (C and D) also shows electropherogram of a neutral electroosmotic flow (EOF) marker dye BODIPY and...internal turbulent mixing . The current microfabricated electromagnets cannot produce sufficient fields to trap the NPs against a large flow forces

Concentration Measurements in a Cold Flow Model Annular Combustor Using Laser Induced Fluorescence

NASA Technical Reports Server (NTRS)

Morgan, Douglas C.

1996-01-01

A nonintrusive concentration measurement method is developed for determining the concentration distribution in a complex flow field. The measurement method consists of marking a liquid flow with a water soluble fluorescent dye. The dye is excited by a two dimensional sheet of laser light. The fluorescent intensity is shown to be proportional to the relative concentration level. The fluorescent field is recorded on a video cassette recorder through a video camera. The recorded images are analyzed with image processing hardware and software to obtain intensity levels. Mean and root mean square (rms) values are calculated from these intensity levels. The method is tested on a single round turbulent jet because previous concentration measurements have been made on this configuration by other investigators. The previous results were used to comparison to qualify the current method. These comparisons showed that this method provides satisfactory results. 'Me concentration measurement system was used to measure the concentrations in the complex flow field of a model gas turbine annular combustor. The model annular combustor consists of opposing primary jets and an annular jet which discharges perpendicular to the primary jets. The mixing between the different jet flows can be visualized from the calculated mean and rms profiles. Concentration field visualization images obtained from the processing provide further qualitative information about the flow field.

Degradation of environment pollutant dyes using phytosynthesized metal nanocatalysts

NASA Astrophysics Data System (ADS)

MeenaKumari, M.; Philip, Daizy

2015-01-01

We present for the first time biogenic reduction and stabilization of gold and silver ions at room temperature using fruit juice of Punica granatum. The formation, morphology and crystalline structure of the synthesized nanoparticles are determined using UV-Visible, XRD and TEM. An attempt to reveal the partial role of phenolic hydroxyls in the reduction of Au3+ and Ag+ is done through FTIR analysis. The synthesized nanoparticles are used as potential catalysts in the degradation of a cationic phenothiazine dye, an anionic mono azo dye and a cationic fluorescent dye. The calculated values of percentage removal of dyes and the rate constants from pseudo first order kinetic data fit give a comparative study on degradation of organic dyes in presence of prepared gold and silver nanoparticles.

Axillary lymph node recurrence after sentinel lymph node biopsy performed using a combination of indocyanine green fluorescence and the blue dye method in early breast cancer.

PubMed

Inoue, Tomoo; Nishi, Toshio; Nakano, Yoshiaki; Nishimae, Ayaka; Sawai, Yuka; Yamasaki, Masaru; Inaji, Hideo

2016-03-01

There is limited information on indocyanine green (ICG) fluorescence and blue dye for detecting sentinel lymph node (SLN) in early breast cancer. A retrospective study was conducted to assess the feasibility of an SLN biopsy using the combination of ICG fluorescence and the blue dye method. Seven hundred and fourteen patients with clinically node-negative breast cancer were included in this study. They underwent SLN biopsy using a combination of ICG fluorescence and the blue dye method from March 2007 to February 2014. The ICG (a fluorescence-emitting source) and patent blue (the blue dye) were injected into the patients' subareolar region. The removed lymph nodes that had ICG fluorescence and/or blue dye uptake were defined as SLNs. The results of the SLN biopsies and follow-up results of patients who underwent SLN biopsy alone were investigated. In 711 out of 714 patients, SLNs were identified by a combination of ICG fluorescence and the blue dye method (detection rate, 99.6 %). The average number of SLNs was 2.4 (range 1-7), and the average number of resected swollen para-SLNs was 0.4 (range 0-5). Ninety-nine patients with an SLN and/or para-SLN involvement during the intraoperative pathological diagnosis underwent axillary lymph node resection (ALND). In addition, two of three patients whose SLN was not identified also underwent ALND. In 46 of 101 patients with an ALND, non-SLN involvement was not found. Follow-up results were analyzed in 464 patients with invasive carcinoma excluding those with ductal carcinoma in situ (n = 148) and those who underwent ALND (n = 101). During the follow-up period (range 4.4-87.7 months; median, 38 months), two patients (0.4 %) developed axillary lymph node recurrence. They were successfully salvaged, and to date, no further locoregional recurrence has been observed. A high rate of SLN detection and low rate of axillary lymph node recurrence were confirmed by an SLN biopsy using a combination of ICG fluorescence and the blue dye method. Therefore, it is suggested that this method may replace the combination of dye and radioisotope methods.

Investigation on Large Molecule Permeation through Liposome Lipid Bilayer Induced by Microplasma Irradiation

NASA Astrophysics Data System (ADS)

Nagaiwa, Hidenori; Aibara, Daijiro; Ikeda, Yoshihisa; Motomura, Hideki; Kido, Yugo; Satoh, Susumu; Tachibana, Kunihide; Jinno, Masahumi

2015-09-01

The authors have been developing a novel gene transfection method using microplasma irradiation. In order to clarify the mechanism of large molecule permeation process through the lipid bilayer, plasma induced outflow of hydrophilic fluorescent dye molecules, which were encapsulated in the liposome, was observed. By microplasma irradiation on the liposome suspension, the dyes flowed out from the inside of the liposomes. The outflow of the dyes was enhanced by longer plasma irradiation time. Investigation of the outflow mechanism, i.e. permeation enhancement of the lipid bilayer or burst of the liposome, is under progress. This work was partly supported by JSPS KAKENHI Grant-in-Aid for Scientific Research on Innovative Areas (Number 25108509,15H00896) and a grant from Ehime University.

Photolysis of Diazo Dye in Aqueous Solutions of Metal Nitrates

NASA Astrophysics Data System (ADS)

Volkova, N. A.; Evstrop'ev, S. K.; Istomina, O. V.; Kolobkova, E. V.

2018-04-01

The photolysis of Chicago Blue Sky diazo dye is studied. It is experimentally shown that the presence of metal nitrates in aqueous solutions changes the photolysis mechanism and sharply increases the photolysis rate.

Fragile X Mental Retardation Protein Restricts Small Dye Iontophoresis Entry into Central Neurons.

PubMed

Kennedy, Tyler; Broadie, Kendal

2017-10-11

Fragile X mental retardation protein (FMRP) loss causes Fragile X syndrome (FXS), a major disorder characterized by autism, intellectual disability, hyperactivity, and seizures. FMRP is both an RNA- and channel-binding regulator, with critical roles in neural circuit formation and function. However, it remains unclear how these FMRP activities relate to each other and how dysfunction in their absence underlies FXS neurological symptoms. In testing circuit level defects in the Drosophila FXS model, we discovered a completely unexpected and highly robust neuronal dye iontophoresis phenotype in the well mapped giant fiber (GF) circuit. Controlled dye injection into the GF interneuron results in a dramatic increase in dye uptake in neurons lacking FMRP. Transgenic wild-type FMRP reintroduction rescues the mutant defect, demonstrating a specific FMRP requirement. This phenotype affects only small dyes, but is independent of dye charge polarity. Surprisingly, the elevated dye iontophoresis persists in shaking B mutants that eliminate gap junctions and dye coupling among GF circuit neurons. We therefore used a wide range of manipulations to investigate the dye uptake defect, including timed injection series, pharmacology and ion replacement, and optogenetic activity studies. The results show that FMRP strongly limits the rate of dye entry via a cytosolic mechanism. This study reveals an unexpected new phenotype in a physical property of central neurons lacking FMRP that could underlie aspects of FXS disruption of neural function. SIGNIFICANCE STATEMENT FXS is a leading heritable cause of intellectual disability and autism spectrum disorders. Although researchers established the causal link with FMRP loss >;25 years ago, studies continue to reveal diverse FMRP functions. The Drosophila FXS model is key to discovering new FMRP roles, because of its genetic malleability and individually identified neuron maps. Taking advantage of a well characterized Drosophila neural circuit, we discovered that neurons lacking FMRP take up dramatically more current-injected small dye. After examining many neuronal properties, we determined that this dye defect is cytoplasmic and occurs due to a highly elevated dye iontophoresis rate. We also report several new factors affecting neuron dye uptake. Understanding how FMRP regulates iontophoresis should reveal new molecular factors underpinning FXS dysfunction. Copyright © 2017 the authors 0270-6474/17/379844-15$15.00/0.

Multiple sort flow cytometer

DOEpatents

Engh, G. van den; Esposito, R.J.

1996-01-09

A flow cytometer utilizes multiple lasers for excitation and respective fluorescence of identified dyes bonded to specific cells or events to identify and verify multiple events to be sorted from a sheath flow and droplet stream. Once identified, verified and timed in the sheath flow, each event is independently tagged upon separation from the flow by an electrical charge of +60, +120, or +180 volts and passed through oppositely charged deflection plates with ground planes to yield a focused six way deflection of at least six events in a narrow plane. 8 figs.

Advanced oxidation of acridine orange by aqueous alkaline iodine.

PubMed

Azmat, Rafia; Qamar, Noshab; Naz, Raheela; Khursheed, Anum

2016-11-01

The advanced oxidation process is certainly used for the dye waste water treatment. In this continuation a new advanced oxidation via aqueous alkaline iodine was developed for the oxidation of acridine orange (AO) {3, 6 -bis (dimethylamino) acridine zinc chloride double salt}. Oxidation Kinetics of AO by alkaline solution of iodine was investigated spectrophotometrically at λ max 491 nm. The reaction was monitored at various operational parameters like several concentrations of dye and iodine, pH, salt electrolyte and temperature. The initial steps of oxidation kinetics followed fractional order reaction with respect to the dye while depend upon the incremental amount of iodine to certain extent whereas maximum oxidation of AO was achieved at high pH. Decline in the reaction rate in the presence of salt electrolyte suggested the presence of oppositely charged species in the rate determining step. Kinetic data revealed that the de-colorization mechanism involves triodate (I 3 - ) species, instead of hypoidate (OI - ) and hypiodous acid (HOI), in alkaline medium during the photo-excitation of hydrolyzed AO. Alleviated concentration of alkali result in decreasing of rate of reaction, clearly indicate that the iodine species are active oxidizing species instead of OH radical. Activation parameters at elevated temperatures were determined which revealed that highly solvated state of dye complex existed into solution. Reaction mixture was subjected to UV/Visible and GC mass spectrum analysis that proves the secondary consecutive reaction was operative in rate determining step and finally dye complex end into smaller fragments.

Method for enhancing cell penetration of Gd3+-based MRI contrast agents by conjugation with hydrophobic fluorescent dyes.

PubMed

Yamane, Takehiro; Hanaoka, Kenjiro; Muramatsu, Yasuaki; Tamura, Keita; Adachi, Yusuke; Miyashita, Yasushi; Hirata, Yasunobu; Nagano, Tetsuo

2011-11-16

Gadolinium ion (Gd(3+)) complexes are commonly used as magnetic resonance imaging (MRI) contrast agents to enhance signals in T(1)-weighted MR images. Recently, several methods to achieve cell-permeation of Gd(3+) complexes have been reported, but more general and efficient methodology is needed. In this report, we describe a novel method to achieve cell permeation of Gd(3+) complexes by using hydrophobic fluorescent dyes as a cell-permeability-enhancing unit. We synthesized Gd(3+) complexes conjugated with boron dipyrromethene (BDP-Gd) and Cy7 dye (Cy7-Gd), and showed that these conjugates can be introduced efficiently into cells. To examine the relationship between cell permeability and dye structure, we further synthesized a series of Cy7-Gd derivatives. On the basis of MR imaging, flow cytometry, and ICP-MS analysis of cells loaded with Cy7-Gd derivatives, highly hydrophobic and nonanionic dyes were effective for enhancing cell permeation of Gd(3+) complexes. Furthermore, the behavior of these Cy7-Gd derivatives was examined in mice. Thus, conjugation of hydrophobic fluorescent dyes appears to be an effective approach to improve the cell permeability of Gd(3+) complexes, and should be applicable for further development of Gd(3+)-based MRI contrast agents.

Optimization and mechanisms for biodecoloration of a mixture of dyes by Trichosporon akiyoshidainum HP 2023.

PubMed

Martorell, María M; Rosales Soro, María Del M; Pajot, Hipólito F; de Figueroa, Lucía I C

2017-09-16

Trichosporon akiyoshidainum HP2023 is a basidiomycetous yeast isolated from Las Yungas rainforest (Tucumán, Argentina) and selected based on its outstanding textile-dye-decolorizing ability. In this work, the decolorization process was optimized using Reactive Black 5 as dye model. Lactose and urea were chosen as carbon and nitrogen sources through a one-at-time approach. Afterwards, factorial designs were employed for medium optimization, leading to the formulation of a simpler optimized medium which contains in g L -1 : lactose 10, yeast extract 1, urea 0.5, KH 2 PO 4 1 and MgSO 4 1. Temperature and agitation conditions were also optimized. The optimized medium and incubation conditions for dye removal were extrapolated to other dyes individually and a mixture of them. Dye removal process happened through both biosorption and biodegradation mechanisms, depending primarily on the dye structure. A positive relation between initial inoculum and dye removal rate and a negative relation between initial dye concentration and final dye removal percentages were found. Under optimized conditions, T. akiyoshidainum HP2023 was able to completely remove a mixture of dyes up to a concentration of 300 mg L -1 , a concentration much higher than those expected in real effluents.

Clinical utility of the additional use of blue dye for indocyanine green for sentinel node biopsy in breast cancer.

PubMed

Ji, Yinan; Luo, Ningbin; Jiang, Yi; Li, Qiuyun; Wei, Wei; Yang, Huawei; Liu, Jianlun

2017-07-01

Indocyanine green (ICG) is widely used as a tracer in sentinel lymph node biopsy (SLNB) of patients with breast cancer. Whether SLNB performance can be improved by supplementing ICG with methylene blue dye remains controversial. This study compared the performance of SLNB when ICG was used alone or with blue dye. Consecutive patients with T1-3 primary breast cancer at our hospital were recruited into our study and randomized to undergo SLNB with ICG alone (n = 62) or with the combination of ICG and blue dye (n = 65). We compared the two methods in terms of identification rate, number and detection time of sentinel lymph nodes (SLNs) removed. SLN identification rate were similar in the absence (95.2%) or presence of blue dye (98.5%, P = 0.578) but significantly, more average nodes were removed when blue dye was used (3.8 ± 1.5 versus 2.7 ± 1.2, P = 0.000), and the average time for detecting each SLN was significantly shorter (3.91 ± 1.87 versus 5.65 ± 2.95 min; P = 0.000). No patient in the study experienced severe adverse reactions or complications. Recurrence of axillary node was detected in one patient (1.6%) using ICG alone but not in any patients using ICG and blue dye. The efficiency and sensitivity of SLNB can be improved by combining ICG with blue dye. Copyright © 2017 Elsevier Inc. All rights reserved.

Gold Decorated Graphene for Rapid Dye Reduction and Efficient Electro Catalytic Oxidation of Ethanol

NASA Astrophysics Data System (ADS)

Siddhardha, R. S.; Kumar v, Lakshman; Kaniyoor, A.; Podila, R.; Kumar, V. S.; Venkataramaniah, K.; Ramaprabhu, S.; Rao, A.; Ramamurthy, S. S.; Clemson University Team; Sri Sathya Sai Institute of Higher Learning Team; IITMadras Team

2013-03-01

A well known disadvantage in fabrication of metal-graphene composite is the use of surfactants that strongly adsorb on the surface and reduce the performance of the catalyst. Here, we demonstrate a novel one pot synthesis of gold nanoparticles (AuNPs) by laser ablation of gold strip and simultaneous decoration of these on functionalized graphene derivatives. Not only the impregnation of AuNPs was linker free, but also the synthesis by itself was surfactant free. This resulted in in-situ decoration of pristine AuNPs on functionalized graphene derivatives. These materials were well characterized and tested for catalytic applications pertaining to dye reduction and electrooxidation. The catalytic reduction rates are 1.4 x 102 and 9.4x102 times faster for Rhodamine B and Methylene Blue dyes respectively, compared to earlier reports. The enhanced rate involves synergistic interplay of electronic relay between AuNPs and the dye, also charge transfer between the graphene system and dye. In addition, the onset potential for ethanol oxidation was found to be more negative ~ 100 mV, an indication of its promising application in direct ethanol fuel cells.

The Comparative Study on the Rapid Decolorization of Azo, Anthraquinone and Triphenylmethane Dyes by Anaerobic Sludge

PubMed Central

Cui, Daizong; Zhang, Hao; He, Rubao; Zhao, Min

2016-01-01

An anaerobic sludge (AS), capable of decolorizing a variety of synthetic dyes, was acclimated and is reported here. The sludge presented a much better dye decolorizing ability than that of different individual strains. A broad spectrum of dyes could be decolorized by the sludge. Continuous decolorization tests showed that the sludge exhibited the ability to decolorize repeated additions of dye. The chemical oxygen demand (COD) removal rate of the dye wastewater reached 52% after 12 h of incubation. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) profiles revealed that the microbial community changed as a result of varying initial concentrations of dyes. Phylogenetic analysis indicated that microbial populations in the sludge belonged to the phyla Acidobacteria, Firmicutes, Bacteroidetes, Chloroflexi and Proteobacteria. The degradation products of the three types of dye were identified. For azo dyes, the anaerobic sludge converted Methyl Orange to N,N-dimethylbenzene-1,4-diamine and 4-aminobenzenesulfonic acid; for triphenylmethane dyes, after Malachite Green was decolorized, the analyzed products were found to be a mixture of N,N-dimethylbenzenamine, 3-dimethyl-aminophenol and 4-dimethylaminobenzophenone; for anthraquinone dyes, two products (acetophenone and 2-methylbenzoic acid) were observed after Reactive Blue 19 decolorization. Together, these results suggest that the anaerobic sludge has promising potential for use in the treatment of industrial wastewater containing various types of dyes. PMID:27801853

Travel times, streamflow velocities, and dispersion rates in the Missouri River upstream from Canyon Ferry Lake, Montana

USGS Publications Warehouse

Whiteman, Aroscott

2012-01-01

In 2010, the U.S. Geological Survey, in cooperation with the Montana Department of Environmental Quality, initiated a dye-tracer study to determine travel times, streamflow velocities, and longitudinal dispersion rates for the Missouri River upstream from Canyon Ferry Lake. For this study, rhodamine WT (RWT) dye was injected at two locations, Missouri River Headwaters State Park in early September and Broadwater-Missouri Dam (Broadwater Dam) in late August 2010. Dye concentrations were measured at three sites downstream from each dye-injection location. The study area was a 41.2-mile reach of the Missouri River from Trident, Montana, at the confluence of the Jefferson, Madison, and Gallatin Rivers (Missouri River Headwaters) at river mile 2,319.40 downstream to the U.S. Route 12 Bridge (Townsend Bridge), river mile 2,278.23, near Townsend, Montana. Streamflows were reasonably steady and ranged from 3,070 to 3,700 cubic feet per second. Mean velocities were calculated for each subreach between measurement sites for the leading edge, peak concentration, centroid, and trailing edge at 10 percent of the peak concentration of the dye plume. Calculated velocities for the centroid of the dye plume ranged from 0.80 to 3.02 feet per second within the study reach from Missouri River Headwaters to Townsend Bridge, near Townsend. The mean velocity of the dye plume for the entire study reach, excluding the subreach between the abandoned Milwaukee Railroad bridge at Lombard, Montana (Milwaukee Bridge) and Broadwater-Missouri Dam (Broadwater Dam), was 2.87 feet per second. The velocity of the centroid of the dye plume for the subreach between Milwaukee Bridge and Broadwater Dam (Toston Reservoir) was 0.80 feet per second. The residence time for Toston Reservoir was 8.2 hours during this study. Estimated longitudinal dispersion rates of the dye plume for this study ranged from 0.72 feet per second for the subreach from Milwaukee Bridge to Broadwater Dam to 2.26 feet per second for the subreach from the U.S. Route 287 Bypass Bridge over the Missouri River north of Toston, Montana to Yorks Islands. A relation was determined between travel time of the peak concentration and the time for the dye plume to pass a site (duration of the dye plume). This relation can be used to estimate when the decreasing concentration of a potential contaminant is reduced to 10 percent of its peak concentration for accidental (contaminant or chemical) spills into the upper Missouri River.

Interdye Hole Transport Accelerates Recombination in Dye Sensitized Mesoporous Films.

PubMed

Moia, Davide; Szumska, Anna; Vaissier, Valérie; Planells, Miquel; Robertson, Neil; O'Regan, Brian C; Nelson, Jenny; Barnes, Piers R F

2016-10-12

Charge recombination between oxidized dyes attached to mesoporous TiO 2 and electrons in the TiO 2 was studied in inert electrolytes using transient absorption spectroscopy. Simultaneously, hole transport within the dye monolayers was monitored by transient absorption anisotropy. The rate of recombination decreased when hole transport was inhibited selectively, either by decreasing the dye surface coverage or by changing the electrolyte environment. From Monte Carlo simulations of electron and hole diffusion in a particle, modeled as a cubic structure, we identify the conditions under which hole lifetime depends on the hole diffusion coefficient for the case of normal (disorder free) diffusion. From simulations of transient absorption and transient absorption anisotropy, we find that the rate and the dispersive character of hole transport in the dye monolayer observed spectroscopically can be explained by incomplete coverage and disorder in the monolayer. We show that dispersive transport in the dye monolayer combined with inhomogeneity in the TiO 2 surface reactivity can contribute to the observed stretched electron-hole recombination dynamics and electron density dependence of hole lifetimes. Our experimental and computational analysis of lateral processes at interfaces can be applied to investigate and optimize charge transport and recombination in solar energy conversion devices using electrodes functionalized with molecular light absorbers and catalysts.

Hydrogen production and metal-dye bioremoval by a Nostoc linckia strain isolated from textile mill oxidation pond.

PubMed

Mona, Sharma; Kaushik, Anubha; Kaushik, C P

2011-02-01

Biohydrogen production by Nostoc linckia HA-46, isolated from a textile-industry oxidation-pond was studied by varying light/dark period, pH, temperature and ratio of carbon-dioxide and argon in the gas-mixture. Hydrogen production rates were maximum under 18 h of light and 6 h of darkness, pH 8.0, 31°C, a CO(2):Ar ratio 2:10. Hydrogen production of the strain acclimatized to 20 mg/L of chromium/cobalt and 100 mg/L of Reactive red 198/crystal violet dye studied in N-supplemented/deficient medium was 6-10% higher in the presence of 1.5 g/L of NaNO(3). Rates of hydrogen production in the presence of dyes/metals by the strain (93-105 μmol/h/mg Chlorophyll) were significantly higher than in medium without metals/dyes serving as control (91.3 μmol/h/mg Chlorophyll). About 58-60% of the two metals and 35-73% of dyes were removed by cyanobacterium. Optimal conditions of temperature, pH and metals/dyes concentration for achieving high hydrogen production and wastewater treatment were found practically applicable as similar conditions are found in the effluent of regional textile-mills. Copyright © 2010 Elsevier Ltd. All rights reserved.

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

PubMed

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

2011-11-01

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 ΔE (CMC) for the proposed method, were found within close proximity to the conventionally dyed sample. Copyright © 2011 Elsevier B.V. All rights reserved.

Optimization of the C11-BODIPY(581/591) dye for the determination of lipid oxidation in Chlamydomonas reinhardtii by flow cytometry.

PubMed

Cheloni, Giulia; Slaveykova, Vera I

2013-10-01

Lipid oxidation is a recognized end point for the study of oxidative stress and is an important parameter to describe the mode of micropollutant action on aquatic microorganisms. Therefore, the development of quick and reliable methodologies probing the oxidative stress and damage in living cells is highly sought. In the present proof-of-concept work, we examined the potential of the fluorescent dye C11-BODIPY(591/581) to probe lipid oxidation in the green microalga Chlamydomonas reinhardtii. C11-BODIPY(591/581) staining was combined with flow cytometry measurements to obtain multiparameter information on cellular features and oxidative stress damage within single cells. First, staining conditions were optimized by exploring the capability of the dye to stain algal cells under increasing cell and dye concentrations and different staining procedures. Then lipid oxidation in algae induced by short- and long-term exposures to the three metallic micropollutants, copper, mercury, and nanoparticulate copper oxide, and the two organic contaminants, diethyldithiocarbamate (DDC) and diuron was determined. In this work we pointed out C11-BODIPY(591/581) applicability in a wide range of exposure conditions, including studies of oxidation as a function of time and that it is suitable for in vivo measurements of lipid oxidation due to its high permeation and stability in cells and its low interference with algal autofluorescence. © 2013 International Society for Advancement of Cytometry. Copyright © 2013 International Society for Advancement of Cytometry.

Optical tracer size differences allow quantitation of active pumping rate versus Stokes-Einstein diffusion in lymphatic transport

NASA Astrophysics Data System (ADS)

DSouza, Alisha V.; Marra, Kayla; Gunn, Jason R.; Samkoe, Kimberley S.; Pogue, Brian W.

2016-10-01

Lymphatic uptake of interstitially administered agents occurs by passive convective-diffusive inflow driven by interstitial concentration and pressure, while the downstream lymphatic transport is facilitated by active propulsive contractions of lymphatic vessel walls. Near-infrared fluorescence imaging in mice was used to measure these central components of lymphatic transport for the first time, using two different-sized molecules-methylene blue (MB) and fluorescence-labeled antibody immunoglobulin G (IgG)-IRDye 680RD. This work confirms the hypothesis that lymphatic passive inflow and active propulsion rates can be separated based upon the relative differences in Stokes-Einstein diffusion coefficient. This coefficient specifically affects the passive-diffusive uptake when the interstitial volume and pressure are constant. Parameters such as mean time-to-peak signal, overall fluorescence signal intensities, and number of active peristaltic pulses, were estimated from temporal imaging data. While the mean time to attain peak signal representative of diffusion-dominated flow in the lymph vessels was 0.6±0.2 min for MB and 8±6 min for IgG, showing a size dependence, the active propulsion rates were 3.4±0.8 pulses/min and 3.3±0.5 pulses/min, respectively, appearing size independent. The propulsion rates for both dyes decreased with clearance from the interstitial injection-site, indicating intrinsic control of the smooth muscles in response to interstitial pressure. This approach to size-comparative agent flow imaging of lymphatic function can enable noninvasive characterization of diseases related to uptake and flow in lymph networks.

Atomic Force Microscope Mediated Chromatography

NASA Technical Reports Server (NTRS)

Anderson, Mark S.

2013-01-01

The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a sliding plate system, consisting of two flat surfaces, one of which has a recessed channel. A fluid flow is produced by axially sliding one plate past another, where the fluid has mechanical shear forces imposed at each point along the channel length. The shear-induced flow rates are very reproducible, and do not have pressure or voltage gradient limitations. SDC opens up a new range of enhanced separation kinetics by permitting the sample confinement with submicron dimensions. Small, highly confined liquid is advantageous for chromatographic separation because the separation rate is known to scale according to the square of the confined sample diameter. In addition, because shear-driven flows are not limited by fluid velocity, shear-driven liquid chromatography may provide up to 100,000 plate efficiency.

Two-Photon Flow Cytometry

NASA Technical Reports Server (NTRS)

Zhog, Cheng Frank; Ye, Jing Yong; Norris, Theodore B.; Myc, Andrzej; Cao, Zhengyl; Bielinska, Anna; Thomas, Thommey; Baker, James R., Jr.

2004-01-01

Flow cytometry is a powerful technique for obtaining quantitative information from fluorescence in cells. Quantitation is achieved by assuring a high degree of uniformity in the optical excitation and detection, generally by using a highly controlled flow such as is obtained via hydrodynamic focusing. In this work, we demonstrate a two-beam, two- channel detection and two-photon excitation flow cytometry (T(sup 3)FC) system that enables multi-dye analysis to be performed very simply, with greatly relaxed requirements on the fluid flow. Two-photon excitation using a femtosecond near-infrared (NIR) laser has the advantages that it enables simultaneous excitation of multiple dyes and achieves very high signal-to-noise ratio through simplified filtering and fluorescence background reduction. By matching the excitation volume to the size of a cell, single-cell detection is ensured. Labeling of cells by targeted nanoparticles with multiple fluorophores enables normalization of the fluorescence signal and thus ratiometric measurements under nonuniform excitation. Quantitative size measurements can also be done even under conditions of nonuniform flow via a two-beam layout. This innovative detection scheme not only considerably simplifies the fluid flow system and the excitation and collection optics, it opens the way to quantitative cytometry in simple and compact microfluidics systems, or in vivo. Real-time detection of fluorescent microbeads in the vasculature of mouse ear demonstrates the ability to do flow cytometry in vivo. The conditions required to perform quantitative in vivo cytometry on labeled cells will be presented.

Biodecolorization of a food azo dye by the deep sea Dermacoccus abyssi MT1.1(T) strain from the Mariana Trench.

PubMed

Lang, Weeranuch; Sirisansaneeyakul, Sarote; Martins, Lígia O; Ngiwsara, Lukana; Sakairi, Nobuo; Pathom-aree, Wasu; Okuyama, Masayuki; Mori, Haruhide; Kimura, Atsuo

2014-01-01

This study reports the characterization of the ability of Dermacoccus spp. isolated from the deepest point of the world's oceans for azo dye decolorization. A detailed investigation of Dermacoccus abyssi MT1.1(T) with respect to the azoreductase activity and enzymatic mechanism as well as the potential role of the bacterial strain for biocleaning of industrial dye baths is reported. Resting cells with oxygen-insensitive azoreductase resulted in the rapid decolorization of the polysulfonated dye Brilliant Black BN (BBN) which is a common food colorant. The highest specific decolorization rate (vs) was found at 50 °C with a moderately thermal tolerance for over 1 h. Kinetic analysis showed the high rates and strong affinity of the enzymatic system for the dye with a Vmax = 137 mg/g cell/h and a Km = 19 mg/L. The degradation of BBN produces an initial orange intermediate, 8-amino-5-((4-sulfonatophenyl)diazenyl)naphthalene-2-sulfonic acid, identified by mass spectrometry which is later converted to 4-aminobenzene sulfonic acid. Nearly 80% of the maximum vs is possible achieved in resting cell treatment with the salinity increased up to 5.0% NaCl in reaction media. Therefore, this bacterial system has potential for dye decolorization bioprocesses occurring at high temperature and salt concentrations e.g. for cleaning dye-containing saline wastewaters. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biconcave micro-optofluidic lens with low-refractive-index liquids.

PubMed

Song, Chaolong; Nguyen, Nam-Trung; Asundi, Anand Krishna; Low, Cassandra Lee-Ngo

2009-12-01

One of the current problems of micro-optofluidics is the choice of a suitable liquid with a high refractive index (RI). We report the use of a low-RI liquid in a biconcave liquid-core liquid-cladding lens for focusing light. For the characterization of the lens, a telescope system was constructed from polydimethylsiloxane lenses to collimate and expand a light beam emitted from an optical fiber. The tunable optofluidic biconcave lens focuses the parallel beam. Fluorescent dye diluted in an index-matching liquid was used for the visualization of the light rays in a beam-tracing chamber. The focused beam is tuned by adjusting the flow rate ratio between core and cladding streams.

Verification of Embolic Channel Causing Blindness Following Filler Injection.

PubMed

Tansatit, Tanvaa; Moon, Hyoung Jin; Apinuntrum, Prawit; Phetudom, Thavorn

2015-02-01

Ocular complications following cosmetic filler injections are serious situations. This study provided scientific evidence that filler in the facial and the superficial temporal arteries could enter into the orbits and the globes on both sides. We demonstrated the existence of an embolic channel connecting the arterial system of the face to the ophthalmic artery. After the removal of the ocular contents from both eyes, liquid dye was injected into the cannulated channel of the superficial temporal artery in six soft embalmed cadavers and different color dye was injected into the facial artery on both sides successively. The interior sclera was monitored for dye oozing from retrograde ophthalmic perfusion. Among all 12 globes, dye injections from the 12 superficial temporal arteries entered ipsilateral globes in three and the contralateral globe in two arteries. Dye from the facial artery was infused into five ipsilateral globes and in three contralateral globes. Dye injections of two facial arteries in the same cadaver resulted in bilateral globe staining but those of the superficial temporal arteries did not. Direct communications between the same and different arteries of the four cannulated arteries were evidenced by dye dripping from the cannulating needle hubs in 14 of 24 injected arteries. Compression of the orbital rim at the superior nasal corner retarded ocular infusion in 11 of 14 arterial injections. Under some specific conditions favoring embolism, persistent interarterial anastomoses between the face and the eye allowed filler emboli to flow into the globe causing ocular complications.

Fast adsorption kinetics of highly dispersed ultrafine nickel/carbon nanoparticles for organic dye removal

NASA Astrophysics Data System (ADS)

Kim, Taek-Seung; Song, Hee Jo; Dar, Mushtaq Ahmad; Lee, Hack-Jun; Kim, Dong-Wan

2018-05-01

Magnetic metal/carbon nano-materials are attractive for pollutant adsorption and removal. In this study, ultrafine nickel/carbon nanoparticles are successfully prepared via electrical wire explosion processing in ethanol media for the elimination of pollutant organic dyes such as Rhodamine B and methylene blue in aqueous solutions. High specific surface areas originating from both the nano-sized particles and the existence of carbon on the surface of Ni nanoparticles enhance dye adsorption capacity. In addition to this, the excellent dispersity of Ni/C nanoparticles in aqueous dye solutions leads to superior adsorption rates. The adsorption kinetics for the removal of organic dyes by Ni/C nanoparticles agree with a pseudo-second-order model and follow Freundlich adsorption isotherm behavior.

Effect of light on the kinetics and equilibrium of the textile dye (Reactive Red 120) adsorption by Helianthus annuus hairy roots.

PubMed

Srikantan, Chitra; Suraishkumar, G K; Srivastava, Smita

2018-06-01

The study demonstrates for the first time that light influences the adsorption equilibrium and kinetics of a dye by root culture system. The azo dye (Reactive Red 120) adsorption by the hairy roots of H. annuus followed a pseudo first-order kinetic model and the adsorption equilibrium parameters were best estimated using Langmuir isotherm. The maximum dye adsorption capacity of the roots increased 6-fold, from 0.26 mg g -1 under complete dark conditions to 1.51 mg g -1 under 16/8 h light/dark photoperiod. Similarly, adsorption rate of the dye and removal (%) also increased in the presence of light, irrespective of the initial concentration of the dye (20-110 mg L -1 ). The degradation of the azo dye upon adsorption by the hairy roots of H. annuus was also confirmed. In addition, a strategy for simultaneous dye removal and increased alpha-tocopherol (industrially relevant) production by H. annuus hairy root cultures has been proposed and demonstrated. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ozonation of exhausted dark shade reactive dye bath for reuse.

PubMed

Sundrarajan, M; Vishnu, G; Joseph, Kurian

2006-10-01

Exhausted reactive dye bath of dark shades were collected from cotton knit wear dyeing units in Tirupur. Ozonation was conducted in a column reactor system fed with ozone at the rate of 0.16 g/min to assess its efficiency in reducing the color, chemical oxygen demand and total organic carbon. The potential of the decolorized dye bath for its repeated reuse was also analyzed. The results from the reusability studies indicate that the dyeing quality was not affected by the reuse of decolorized dye bath for two successive cycles. Complete decolorization of the effluent was achieved in 60 minutes contact time at an ozone consumption of 183 mg/L for Red, 175 for Navy Blue and 192 for Green shades respectively. The corresponding COD removal was 60%, 54% and 63% for the three shades while TOC removal efficiency was 59%, 55% and 62% respectively. It is concluded that ozonation is efficient in decolorization of exhausted dye bath effluents containing conventional reactive dyes. However, the corresponding removal of COD from the textile effluent was not significant.

Stereo-PIV study of flow inside an eye under cataract surgery

NASA Astrophysics Data System (ADS)

Sakakibara, Jun; Yamashita, Masaki; Kobayashi, Tatsuya; Kaji, Yuichi; Oshika, Tetsuro

2012-04-01

We measured velocity distributions in the anterior chamber of porcine eyes under simulated cataract surgery using stereoscopic particle image velocimetry (stereo-PIV). The surface of the cornea was detected based on the images of laser-induced fluorescent light emitted from fluorescent dye solution introduced in a posterior chamber. A coaxial phacoemulsification procedure was simulated with standard size (standard coaxial phacoemulsification) and smaller (micro coaxial phacoemulsification) surgical instruments. In both cases, an asymmetric flow rate of irrigation was observed, although both irrigation ports had the same dimensions prior to insertion into the eye. In cases where the tip of the handpiece was placed farther away from the top of the cornea, i.e., closer to the crystalline lens, direct impingement of irrigation flow onto the cornea surface was avoided and the flow turned back toward the handpiece along the surface of the corneal endothelium. Viscous shear stress on the corneal endothelium was computed based on the measured mean velocity distribution. The maximum shear stress for most cases exceeded 0.1 Pa, which is comparable to the shear stress that caused detachment of the corneal endothelial cells reported by Kaji et al. in Cornea 24:S55-S58, (2005). When direct impingement of the irrigation flow was avoided, the shear stress was reduced considerably.

Quantitative fluorescence angiography for neurosurgical interventions.

PubMed

Weichelt, Claudia; Duscha, Philipp; Steinmeier, Ralf; Meyer, Tobias; Kuß, Julia; Cimalla, Peter; Kirsch, Matthias; Sobottka, Stephan B; Koch, Edmund; Schackert, Gabriele; Morgenstern, Ute

2013-06-01

Present methods for quantitative measurement of cerebral perfusion during neurosurgical operations require additional technology for measurement, data acquisition, and processing. This study used conventional fluorescence video angiography--as an established method to visualize blood flow in brain vessels--enhanced by a quantifying perfusion software tool. For these purposes, the fluorescence dye indocyanine green is given intravenously, and after activation by a near-infrared light source the fluorescence signal is recorded. Video data are analyzed by software algorithms to allow quantification of the blood flow. Additionally, perfusion is measured intraoperatively by a reference system. Furthermore, comparing reference measurements using a flow phantom were performed to verify the quantitative blood flow results of the software and to validate the software algorithm. Analysis of intraoperative video data provides characteristic biological parameters. These parameters were implemented in the special flow phantom for experimental validation of the developed software algorithms. Furthermore, various factors that influence the determination of perfusion parameters were analyzed by means of mathematical simulation. Comparing patient measurement, phantom experiment, and computer simulation under certain conditions (variable frame rate, vessel diameter, etc.), the results of the software algorithms are within the range of parameter accuracy of the reference methods. Therefore, the software algorithm for calculating cortical perfusion parameters from video data presents a helpful intraoperative tool without complex additional measurement technology.

Comparative Evaluation of Sealing Ability of Three Newer Root Canal Obturating Materials Guttaflow, Resilon and Thermafil: An In Vitro Study

PubMed Central

H Bhandi, Shilpa; T S, Subhash

2013-01-01

Introduction: Microleakage continues to be a main reason for failure of root canal treatment where the challenge has been to achieve an adequate seal between the internal structure and the main obturating material. The objective of this study is to compare the sealing ability of 3 newer obturating materials GuttaFlow, Resilon/Epiphany system (RES) and Thermafil, using silver nitrate dye and observing under stereomicroscope. Methodology: Thirty single rooted teeth were divided into following groups. Group I : GuttaFlow ;Group II : Resilon /Epiphany sealer Group III : Thermafil with AH-Plus sealer. Teeth were decoronated and instrumented with profile rotary system and obturated with specified materials. Apical seal was determined by dye penetration method using silver nitrate. Then the specimens were transversely sectioned at each mm till 3 mm from the apex. Dye leakage was determined using stereomicroscope. Statistical analysis of the results was performed using Kruskall-Wallis test. Results: The results showed that Group II i.e., Resilon with Epiphany sealer showed the least amount of microleakage when compared to Group I i.e., GuttaFlow and Group III i.e., Thermafil with AH-plus sealer. Conclusion: Based on the results of this study it can be concluded that RES had higher sealing ability followed by Thermafil and GuttaFlow in vitro but further studies have to be carried out to make a direct correlation between these results and invivo situation. How to cite this article: Bhandi S H, Subhash T S. Comparative Evaluation of Sealing Ability of Three Newer Root Canal Obturating Materials Guttaflow, Resilon and Thermafil: An In Vitro Study. J Int Oral Health 2013; 5(1):54-65. PMID:24155579

Experimental Study on Treatment of Dyeing Wastewater by Activated Carbon Adsorption, Coagulation and Fenton Oxidation

NASA Astrophysics Data System (ADS)

Xiaoxu, SUN; Jin, XU; Xingyu, LI

2017-12-01

In this paper dyeing waste water was simulated by reactive brilliant blue XBR, activated carbon adsorption process, coagulation process and chemical oxidation process were used to treat dyeing waste water. In activated carbon adsorption process and coagulation process, the water absorbance values were measured. The CODcr value of water was determined in Fenton chemical oxidation process. Then, the decolorization rate and COD removal rate were calculated respectively. The results showed that the optimum conditions of activated carbon adsorption process were as follows: pH=2, the dosage of activated carbon was 1.2g/L, the adsorption reaction time was 60 min, and the average decolorization rate of the three parallel experiments was 85.30%. The optimum conditions of coagulation experiment were as follows: pH=8~9, PAC dosage was 70mg/L, stirring time was 20min, standing time was 45min, the average decolorization rate of the three parallel experiments was 74.48%. The optimum conditions for Fenton oxidation were Fe2+ 0.05g/L, H2O2 (30%) 14mL/L, pH=3, reaction time 40min. The average CODcr removal rate was 69.35% in three parallel experiments. It can be seen that in the three methods the activated carbon adsorption treatment of dyeing wastewater was the best one.

Homogeneous plate based antibody internalization assay using pH sensor fluorescent dye.

PubMed

Nath, Nidhi; Godat, Becky; Zimprich, Chad; Dwight, Stephen J; Corona, Cesear; McDougall, Mark; Urh, Marjeta

2016-04-01

Receptor-mediated antibody internalization is a key mechanism underlying several anti-cancer antibody therapeutics. Delivering highly toxic drugs to cancer cells, as in the case of antibody drug conjugates (ADCs), efficient removal of surface receptors from cancer cells and changing the pharmacokinetics profile of the antibody drugs are some of key ways that internalization impacts the therapeutic efficacy of the antibodies. Over the years, several techniques have been used to study antibody internalization including radiolabels, fluorescent microscopy, flow cytometry and cellular toxicity assays. While these methods allow analysis of internalization, they have limitations including a multistep process and limited throughput and are generally endpoint assays. Here, we present a new homogeneous method that enables time and concentration dependent measurements of antibody internalization. The method uses a new hydrophilic and bright pH sensor dye (pHAb dye), which is not fluorescent at neutral pH but becomes highly fluorescent at acidic pH. For receptor mediated antibody internalization studies, antibodies against receptors are conjugated with the pHAb dye and incubated with the cells expressing the receptors. Upon binding to the receptor, the dyes conjugated to the antibody are not fluorescent because of the neutral pH of the media, but upon internalization and trafficking into endosomal and lysosomal vesicles the pH drops and dyes become fluorescent. The enabling attributes of the pHAb dyes are the hydrophilic nature to minimize antibody aggregation and bright fluorescence at acidic pH which allows development of simple plate based assays using a fluorescent reader. Using two different therapeutic antibodies--Trastuzumab (anti-HER2) and Cetuximab (anti-EGFR)--we show labeling with pHAb dye using amine and thiol chemistries and impact of chemistry and dye to antibody ration on internalization. We finally present two new approaches using the pHAb dye, which will be beneficial for screening a large number of antibody samples during early monoclonal development phase. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Aerobic Biodegradation Characteristic of Different Water-Soluble Azo Dyes

PubMed Central

Sheng, Shixiong; Liu, Bo; Hou, Xiangyu; Wu, Bing; Yao, Fang; Ding, Xinchun; Huang, Lin

2017-01-01

This study investigated the biodegradation performance and characteristics of Sudan I and Acid Orange 7 (AO7) to improve the biological dye removal efficiency in wastewater and optimize the treatment process. The dyes with different water-solubility and similar molecular structure were biologically treated under aerobic condition in parallel continuous-flow mixed stirred reactors. The biophase analysis using microscopic examination suggested that the removal process of the two azo dyes is different. Removal of Sudan I was through biosorption, since it easily assembled and adsorbed on the surface of zoogloea due to its insolubility, while AO7 was biodegraded incompletely and bioconverted, the AO7 molecule was decomposed to benzene series and inorganic ions, since it could reach the interior area of zoogloea due to the low oxidation-reduction potential conditions and corresponding anaerobic microorganisms. The transformation of NH3-N, SO42− together with the presence of tryptophan-like components confirm that AO7 can be decomposed to non-toxic products in an aerobic bioreactor. This study provides a theoretical basis for the use of biosorption or biodegradation mechanisms for the treatment of different azo dyes in wastewater. PMID:29278390

Traveltime and dispersion in the Illinois River, Marseilles to Peoria, Illinois

USGS Publications Warehouse

Zuehls, E.E.

1987-01-01

Traveltime in 89.3 mi of the Illinois River between Marseilles Dam and Peoria Dam was measured using rhodamine-WT dye. On each of four subreaches, dye-tracer measurements were made at approximately 50- and 85% flow duration in 1978, 1979, and 1985. The dye-tracer data were used to develop a method for estimating the traveltime and peak concentration of a solute spilled into the Illinois River. The estimates can apply to spills at any point within the study reach during a period of relatively steady discharge of from low to medium streamflow. A sample problem to demonstrate the estimating method is solved for a hypothetical situation in which 100,000 pounds of contaminant is spilled at a railroad crossing between Spring Valley and Hennepin, Illinois. (USGS)

Optofluidic-Tunable Color Filters And Spectroscopy Based On Liquid-Crystal Microflows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cuennet, J. G.; Vasdekis, Andreas E.; Psaltis, D.

The integration of color filters with microfluidics has attracted substantial attention in recent years, for on-chip absorption, fluorescence, or Raman analysis. We describe such tunable filters based on the micro-flow of liquid crystals. The filter operation is based on the wavelength dependent liquid crystal birefringence that can be tuned by modifying the flow velocity field in the microchannel. The latter is possible both temporally and spatially by varying the inlet pressure and the channel geometry respectively. We explored the use of these optofluidic filters for on-chip absorption spectroscopy; by integrating the distance dependent color filter with a dye-filled micro-channel, themore » absorption spectrum of a dye could be measured. Liquid crystal microflows simplify substantially the optofluidic integration, actuation and tuning of color filters for lab-on-a-chip spectroscopic applications.« less

Rapid flow cytometry analysis of antimicrobial properties of nettle powder and cranberry powder

NASA Astrophysics Data System (ADS)

Hattuniemi, Maarit; Korhonen, Johanna; Jaakkola, Mari; Räty, Jarkko; Virtanen, Vesa

2010-11-01

Both nettle (Urtica dioica) and cranberry (Vaccinium oxycoccus) are widely known to have good influence on health. The aim of this study was to investigate antimicrobial properties of nettle powder and cranberry powder against Escherichia coli (E. coli) and monitor the growth of the bacteria by a rapid flow cytometry (FCM) method. For FCM measurements samples were stained with fluorescent dyes. The inhibitory effects of plant material on growth of E. coli were estimated by comparing the results of control sample (E. coli) to E. coli samples with plant material. FCM offers both a brilliant tool to investigate the kinetics of the growth of bacterium, since subsamples can be taken from the same liquid medium during the growing period and with fluorescent dyes a rapid method to investigate viability of the bacterium.

Functional expression of Ca²⁺ dependent mammalian transmembrane gap junction protein Cx43 in slime mold Dictyostelium discoideum.

PubMed

Kaufmann, Stefan; Weiss, Ingrid M; Eckstein, Volker; Tanaka, Motomu

2012-03-09

In this paper, we expressed murine gap junction protein Cx43 in Dictyostelium discoideum by introducing the specific vector pDXA. In the first step, the successful expression of Cx43 and Cx43-eGFP was verified by (a) Western blot (anti-Cx43, anti-GFP), (b) fluorescence microscopy (eGFP-Cx43 co-expression, Cx43 immunostaining), and (c) flow cytometry analysis (eGFP-Cx43 co-expression). Although the fluorescence signals from cells expressing Cx43-eGFP detected by fluorescence microscopy seem relatively low, analysis by flow cytometry demonstrated that more than 60% of cells expressed Cx43-eGFP. In order to evaluate the function of expressed Cx43 in D. discoideum, we examined the hemi-channel function of Cx43. In this series of experiments, the passive uptake of carboxyfluorescein was monitored using flow cytometric analysis. A significant number of the transfected cells showed a prominent dye uptake in the absence of Ca(2+). The dye uptake by transfected cells in the presence of Ca(2+) was even lower than the non-specific dye uptake by non-transformed Ax3 orf+ cells, confirming that Cx43 expressed in D. discoideum retains its Ca(2+)-dependent, specific gating function. The expression of gap junction proteins expressed in slime molds opens a possibility to the biological significance of intercellular communications in development and maintenance of multicellular organisms. Copyright © 2012 Elsevier Inc. All rights reserved.

Impacts of dyebath auxiliaries on the reductive discoloration of Acid Orange 7 dye by high-carbon iron filings.

PubMed

Kumar, Raja; Sinha, Alok

This study proposed that the physicochemical effects of common dyebath auxiliaries on the bulk dye solution as well as on the iron surface can influence the reductive discoloration of effluent containing Acid Orange 7 (AO7) dye using high-carbon iron filings. Sodium chloride increased the discoloration rate because of the pitting corrosion on the iron surface, triggered by chloride anion. 'Salting out' effect of ammonium sulfate improved the reaction rate up to a certain concentration, beyond which it could compete with dye molecules for the reactive sites, as revealed by formed sulfite and sulfide. Urea drastically reduced the discoloration rates by its chaotropic effect on the bulk solution and by wrapping around the iron surface. Organic acids, namely acetic acid and citric acid, stimulated iron corrosion to improve the discoloration rates. The discoloration reaction was biphasic with an initial fast reaction phase, where in every case more than 70% discoloration was observed within 5 min of reaction, preceding a slow reaction phase. The experimental data could be well described using biphasic kinetics equation (R(2)> 0.997 in all cases) and a biphasic equation was developed considering the individual impact of co-existing auxiliaries on AO7 discoloration.

Effect of auxiliary group for p-type organic dyes in NiO-based dye-sensitized solar cells: The first principal study

NASA Astrophysics Data System (ADS)

Li, Juan; Zhang, Shijie; Shao, Di; Yang, Zhenqing; Zhang, Wansong

2018-03-01

Auxiliary acceptor groups play a crucial role in D-A-π-A structured organic dyes. In this paper, we designed three D-A-π-A structured organic molecules based on the prototype dye QT-1, named ME18-ME20, and further investigated their electronic and optical properties with density functional theory (DFT) and time-dependent DFT (TDDFT). The calculated results indicate that the scope and intensity of dyes' absorption spectra have some outstanding changes by inserting auxiliary groups. ME20 has not only 152 nm redshifts to long wave orientation, but also 78% increased oscillator strength compared to QT-1, and its absorption spectrum broadens region even up to 1400 nm. Then, we studied the reason that the effect of the introduced different auxiliary acceptor groups in these dyes through their ground states geometries and energy levels, electron transfer and recombination rate.

Removal of Congo red dye from aqueous solutions using a halloysite-magnetite-based composite.

PubMed

Ferrarini, F; Bonetto, L R; Crespo, Janaina S; Giovanela, M

2016-01-01

Adsorption has been considered as one of the most effective methods to remove dyes from aqueous solutions due to its ease of operation, high efficiency and wide adaptability. In view of all these aspects, this study aimed to evaluate the adsorption capacity of a halloysite-magnetite-based composite in the removal of Congo red dye from aqueous solutions. The effects of stirring rate, pH, initial dye concentration and contact time were investigated. The results revealed that the adsorption kinetics followed the pseudo-second-order model, and equilibrium was well represented by the Brunauer-Emmett-Teller isotherm. The thermodynamic data showed that dye adsorption onto the composite was spontaneous and endothermic and occurred by physisorption. Finally, the composite could also be regenerated at least four times by calcination and was shown to be a promising adsorbent for the removal of this dye.

Measurement of ground water velocity using Rhodamine WT dye near Sheffield, Illinois

USGS Publications Warehouse

Garklavs, George; Toler, L.G.

1985-01-01

Ground-water flow velocity was estimated in a tract of land adjacent to a low-level radioactive-waste disposal site near Sheffield, Illinois, by measuring the time-of-travel between two wells spaced 110 feet apart. Rhodamine WT dye was the principal tracer used in the test. The leading edge and peak concentrations of Rhodamine WT were well defined. A ground-water velocity of 6.9 feet per day (2,500 feet per year) was computed from the arrival time of the leading edge of the tracer cloud. (USGS)

Water tunnel flow visualization using a laser

NASA Technical Reports Server (NTRS)

Beckner, C.; Curry, R. E.

1985-01-01

Laser systems for flow visualization in water tunnels (similar to the vapor screen technique used in wind tunnels) can provide two-dimensional cross-sectional views of complex flow fields. This parametric study documents the practical application of the laser-enhanced visualization (LEV) technique to water tunnel testing. Aspects of the study include laser power levels, flow seeding (using flourescent dyes and embedded particulates), model preparation, and photographic techniques. The results of this study are discussed to provide potential users with basic information to aid in the design and setup of an LEV system.

A solar rechargeable flow battery based on photoregeneration of two soluble redox couples.

PubMed

Liu, Ping; Cao, Yu-liang; Li, Guo-Ran; Gao, Xue-Ping; Ai, Xin-Ping; Yang, Han-Xi

2013-05-01

Storable sunshine, reusable rays: A solar rechargeable redox flow battery is proposed based on the photoregeneration of I(3)(-)/I(-) and [Fe(C(10)H(15))(2)](+)/Fe(C(10)H(15))(2) soluble redox couples, which can be regenerated by flowing from a discharged redox flow battery (RFB) into a dye-sensitized solar cell (DSSC) and then stored in tanks for subsequent RFB applications This technology enables effective solar-to-chemical energy conversion. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultralow temperature synthesis and improved adsorption performance of graphene oxide nanosheets

NASA Astrophysics Data System (ADS)

Tao, Xiaojun; Wang, Xiaodong; Li, Zhiwei; Zhou, Shaomin

2015-01-01

In this article, we first report an ultralow temperature (-60 °C) synthesis of graphene oxide nanosheets (GONs), which is achieved via the reduction reaction of tetrachloroethylene (C2Cl4) and potassium in liquid ammonia solution at atmospheric pressure. The as-obtained multilayer GONs with a high quality exhibit a low C/O atomic ratio of approximately 2:1, indicating that GONs are rich in the oxygen-containing functional groups. In order to improve their adsorption property, GONs are reduced at 500 °C for 2 h in flowing N2, which results in the successful preparation of graphene nanosheets (GNs) with a high C/O atomic ratio of approximately 32:1. GNs show high specific surface area (508 m2/g), high adsorption capacity (Qe = 148.36 mg/g, Co = 180 mg/L), and rapid adsorption rate (>96%, 10 min) of organic dye rhodamine B (RhB) from water, suggesting that GNs have potential environmental applications as alternatives to commercial materials in wastewater treatment for the removal of organic dye. Compared with the reported methods to prepare GONs, our techniques have attractive advantages, such as low reaction temperature and being friendly to environment.

Free-fall dynamics of a pair of rigidly linked disks

NASA Astrophysics Data System (ADS)

Kim, Taehyun; Chang, Jaehyeock; Kim, Daegyoum

2018-03-01

We investigate experimentally the free-fall motion of a pair of identical disks rigidly connected to each other. The three-dimensional coordinates of the pair of falling disks were constructed to quantitatively describe its trajectory, and the flow structure formed by the disk pair was identified by using dye visualization. The rigidly linked disk pair exhibits a novel falling pattern that creates a helical path with a conical configuration in which the lower disk rotates in a wider radius than the upper disk with respect to a vertical axis. The helical motion occurs consistently for the range of disk separation examined in this study. The dye visualization reveals that a strong, noticeable helical vortex core is generated from the outer tip of the lower disk during the helical motion. With an increasing length ratio, which is the ratio of the disk separation to the diameter of the disks, the nutation angle and the rate of change in the precession angle that characterize the combined helical and conical kinematics decrease linearly, whereas the pitch of the helical path increases linearly. Although all disk pairs undergo this helical motion, the horizontal-drift patterns of the disk pair depend on the length ratio.

Application potential of grapefruit peel as dye sorbent: kinetics, equilibrium and mechanism of crystal violet adsorption.

PubMed

Saeed, Asma; Sharif, Mehwish; Iqbal, Muhammad

2010-07-15

This study reports the sorption of crystal violet (CV) dye by grapefruit peel (GFP), which has application potential in the remediation of dye-contaminated wastewaters using a solid waste generated by the citrus fruit juice industry. Batch adsorption of CV was conducted to evaluate the effect of initial pH, contact time, temperature, initial dye concentration, GFP adsorbent dose, and removal of the adsorbate CV dye from aqueous solution to understand the mechanism of sorption involved. Sorption equilibrium reached rapidly with 96% CV removal in 60 min. Fit of the sorption experimental data was tested on the pseudo-first and pseudo-second-order kinetics mathematical equations, which was noted to follow the pseudo-second-order kinetics better, with coefficient of correlation > or = 0.992. The equilibrium process was well described by the Langmuir isotherm model, with maximum sorption capacity of 254.16 mg g(-1). The GFP was regenerated using 1 M NaOH, with up to 98.25% recovery of CV and could be reused as a dye sorbent in repeated cycles. GFP was also shown to be highly effective in removing CV from aqueous solution in continuous-flow fixed-bed column reactors. The study shows that GFP has the potential of application as an efficient sorbent for the removal of CV from aqueous solutions. 2010 Elsevier B.V. All rights reserved.

Photoacoustic-fluorescence in vitro flow cytometry for quantification of absorption, scattering and fluorescence properties of the cells

NASA Astrophysics Data System (ADS)

Nedosekin, D. A.; Sarimollaoglu, M.; Foster, S.; Galanzha, E. I.; Zharov, V. P.

2013-03-01

Fluorescence flow cytometry is a well-established analytical tool that provides quantification of multiple biological parameters of cells at molecular levels, including their functional states, morphology, composition, proliferation, and protein expression. However, only the fluorescence and scattering parameters of the cells or labels are available for detection. Cell pigmentation, presence of non-fluorescent dyes or nanoparticles cannot be reliably quantified. Herewith, we present a novel photoacoustic (PA) flow cytometry design for simple integration of absorbance measurements into schematics of conventional in vitro flow cytometers. The integrated system allow simultaneous measurements of light absorbance, scattering and of multicolor fluorescence from single cells in the flow at rates up to 2 m/s. We compared various combinations of excitation laser sources for multicolor detection, including simultaneous excitation of PA and fluorescence using a single 500 kHz pulsed nanosecond laser. Multichannel detection scheme allows simultaneous detection of up to 8 labels, including 4 fluorescent tags and 4 PA colors. In vitro PA-fluorescence flow cytometer was used for studies of nanoparticles uptake and for the analysis of cell line pigmentation, including genetically encoded melanin expression in breast cancer cell line. We demonstrate that this system can be used for direct nanotoxicity studies with simultaneous quantification of nanoparticles content and assessment of cell viability using a conventional fluorescent apoptosis assays.

Flow cytometric HyPer-based assay for hydrogen peroxide.

PubMed

Lyublinskaya, O G; Antonov, S A; Gorokhovtsev, S G; Pugovkina, N A; Kornienko, Ju S; Ivanova, Ju S; Shatrova, A N; Aksenov, N D; Zenin, V V; Nikolsky, N N

2018-05-30

HyPer is a genetically encoded fluorogenic sensor for hydrogen peroxide which is generally used for the ratiometric imaging of H 2 O 2 fluxes in living cells. Here, we demonstrate the advantages of HyPer-based ratiometric flow cytometry assay for H 2 O 2 , by using K562 and human mesenchymal stem cell lines expressing HyPer. We show that flow cytometry analysis is suitable to detect HyPer response to submicromolar concentrations of extracellularly added H 2 O 2 that is much lower than concentrations addressed previously in the other HyPer-based assays (such as cell imaging or fluorimetry). Suggested technique is also much more sensitive to hydrogen peroxide than the widespread flow cytometry assay exploiting H 2 O 2 -reactive dye H 2 DCFDA and, contrary to the H 2 DCFDA-based assay, can be employed for the kinetic studies of H 2 O 2 utilization by cells, including measurements of the rate constants of H 2 O 2 removal. In addition, flow cytometry multi-parameter ratiometric measurements enable rapid and high-throughput detection of endogenously generated H 2 O 2 in different subpopulations of HyPer-expressing cells. To sum up, HyPer can be used in multi-parameter flow cytometry studies as a highly sensitive indicator of intracellular H 2 O 2 . Copyright © 2018. Published by Elsevier Inc.

97% accuracy of intra-articular glenohumeral injection with a modified (Delaware) posterior bone touch technique.

PubMed

Axe, Jeremie M; Axe, Michael J

2013-10-01

Unguided approaches have not demonstrated evidence of highly accurate intra-articular glenohumeral injections. The purpose of this study was to assess the accuracy of a posterior approach bone touch technique in conscious subjects without shoulder pathology as a first step in developing an accurate, reliable technique for use in patients. Twenty-six young subjects (age 22-26) without shoulder pathology (BMI 24 +/- 3), had bilateral shoulders injected while awake and seated. A 20 gauge 3.5-inch needle was introduced 1.5 cm below the scapular spine mid-way between the posterior lateral acromial corner and the posterior axillary crease. In Trial I, 20 shoulders were injected. After touching the humerus, the arm was oscillated. The needle advanced to 4-5 cm and 10 mL of dye injected. Pop and ease of flow were recorded. Immediate room change, spot fluoroscopy, and independent experienced radiology reading followed. In Trial II, 32 shoulders were injected. The technique was modified to touching the humerus, externally rotating the arm 25 degrees, and while remaining in bone contact, delivering 10 mL of dye. The same data as Trial I was recorded. In Trial I, 14/20 (70 percent) had dye within the glenohumeral joint. Five of seven failures were too anterior showing dye around the subscapularis muscle and all were associated with a pop. In Trial II, 31/32 (97 percent) had dye within glenohumeral joint. Twenty-three of 32 (72 percent) had a "pop," including the failure. Overall, 45/52 (87 percent) had dye within glenohumeral joint. Thirty-one of 52 (71 percent) of all shoulders had a "pop." Twenty-three of 52 (44 percent) shoulders had pain, resolving within 24 hours. A modified (Delaware) posterior bone touch technique for glenohumeral joint injection is 97 percent accurate in conscious healthy young subjects. Pop and ease of flow are not always indicative of correct needle placement. This study serves as an important first step in determining an optimum approach for injecting pathologic glenohumeral joints with corticosteroids or hyaluronic acid. IV Case Series.

Phosphorus exchangeability and leaching losses from two grassland soils.

PubMed

Sinaj, S; Stamm, C; Toor, G S; Condron, L M; Hendry, T; Di, H J; Cameron, K C; Frossard, E

2002-01-01

Although phosphate phosphorus (P) is strongly sorbed in many soils, it may be quickly transported through the soil by preferential flow. Under flood irrigation, preferential flow is especially pronounced and associated solute losses may be important. Phosphorus losses induced by flood irrigation were investigated in a lysimeter study. Detailed soil chemical analyses revealed that P was very mobile in the topsoil, but the higher P-fixing capacity of the subsoil appeared to restrict P mobility. Application of a dye tracer enabled preferential flow pathways to be identified. Soil sampling according to dye staining patterns revealed that exchangeable P was significantly greater in preferential flow areas as compared with the unstained soil matrix. This could be partly attributed to the accumulation of organic carbon and P, together with enhanced leaching of Al- and Fe-oxides in the preferential flow areas, which resulted in reduced P sorption. The irrigation water caused a rapid hydrologic response by displacement of resident water from the subsoil. Despite the occurrence of preferential flow, most of the outflowing water was resident soil water and very low in P. In these soils the occurrence of preferential flow per se is not sufficient to cause large P losses even if the topsoil is rich in P. It appears that the P was retained in lower parts of the soil profile characterized by a very high P-fixing capacity. This study demonstrates the risks associated with assessing potential P losses on the basis of P mobility in the topsoil alone.

Performance of a nonlaser light source for photodynamic therapy

NASA Astrophysics Data System (ADS)

Whitehurst, Colin; Byrne, Karen T.; Morton, Colin; Moore, James V.

1995-03-01

Advances in short arc technology and optical filter coatings led to the design and construction of a table-top light source in 1989; the first viable and cost-effective alternative to a laser. The device can deliver over 3 W within a 30 nm band centered at any wavelength from 200 nm to 1200 nm at fluence rates of over 1 W cm-2. Its relative biological effectiveness (RBE) in vitro has been proven alongside an argon pumped dye laser and a copper vapor pumped dye laser. These in vitro tests showed an efficiency of hematoporphyrin derivative (HPD) induced cellular photoinactivation close to that of the argon/dye laser (RBE 100%), with a mean RBE for the lamp of 87 +/- 3% (p < 0.05). The lamp proved to be superior to that of the copper/dye laser system with an RBE of up to 150% at fluence rates above 50 mWcm-2. In vivo tests show that the extent and depth of tumor necrosis are comparable to that of an argon/dye laser. An in situ bioassay using tumor regrowth delay is currently underway. Early clinical trials show clearance of Bowen's disease and actinic keratosis using the same light fluences as costly PDT lasers.

Determination of stream reaeration coefficients by use of tracers

USGS Publications Warehouse

Kilpatrick, F.A.; Rathbun, R.E.; Yotsukura, N.; Parker, G.W.; DeLong, L.L.

1987-01-01

Stream reaeration is the physical absorption of oxygen from the atmosphere by a flowing stream. This is the primary process by which a stream replenishes the oxygen consumed in the biodegradation of organic wastes.Prior to 1965, reaeration rate coefficients could be estimated only by indirect methods. In 1965, a direct method of measuring stream reaeration coefficients was developed in which a radioactive tracer gas was injected into a stream--the tracer gas being desorbed from the stream inversely to how oxygen would be absorbed. The technique has since been modified by substituting hydrocarbon gases for the radioactive tracer gas.This manual describes the slug-injection and constant-rate injection methods of performing gas-tracer desorption measurements. Emphasis is on the use of rhodamine WT dye as a relatively conservative tracer and propane as the nonconservative gas tracer, on planning field tests, methods of injection, sampling and analysis, and computational techniques to compute desorption and reaeration coefficients.

Contact sensitizers in commercial hair dye products sold in Thailand.

PubMed

Boonchai, Waranya; Bunyavaree, Monthathip; Winayanuwattikun, Waranaree; Kasemsarn, Pranee

2016-04-01

Hair dyes are known to contain potent contact allergens for which sensitization rates have increased over the last decade. To examine the type and frequency of potent contact sensitizers labelled on hair dyes sold in metropolitan Bangkok, Thailand. During the 2013-2014 study period, labelled ingredient information from home use and professional hair dye products was collected. Two hundred and fifty-two hair dye products were evaluated. One hundred and forty-nine products from 48 brands were domestically produced in Thailand, and 103 products were from 23 multinational brands produced in countries other than Thailand. Two hundred and fourteen of 252 (84.9%) hair dye products were found to contain strong skin sensitizers, with 118 (46.8%) being found in domestically produced products, and 96 (38.1%) being found in multinational brand products. Thirty-eight hair dye products (15.1%) were free of potent skin sensitizers. The number of domestically produced products (31, 20.8%) that were free of potent skin sensitizers was significantly higher (p = 0.002) than the number of multinational brand products (7, 6.8%). p-Phenylenediamine was the most prevalent potent sensitizer found among domestically produced hair dyes available on the market. Our findings indicate regional differences in hair dye allergen exposure. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Growth and physiology of Clostridium perfringens wild-type and ΔazoC knockout: an azo dye exposure study.

PubMed

Morrison, Jessica M; John, Gilbert H

2016-02-01

Clostridium perfringens, a strictly anaerobic micro-organism and inhabitant of the human intestine, has been shown to produce the azoreductase enzyme AzoC, an NAD(P)H-dependent flavin oxidoreductase. This enzyme reduces azo dyes to aromatic amines, which are carcinogenic in nature. A significant amount of work has been completed that focuses on the activity of this enzyme; however, few studies have been completed that focus on the physiology of azo dye reduction. Dye reduction studies coupled with C. perfringens growth studies in the presence of ten different azo dyes and in media of varying complexities were completed to compare the growth rates and dye-reducing activity of C. perfringens WT cells, a C. perfringens ΔazoC knockout, and Bifidobacterium infantis, a non-azoreductase-producing control bacterium. The presence of azo dyes significantly increased the generation time of C. perfringens in rich medium, an effect that was not seen in minimal medium. In addition, azo dye reduction studies with the ΔazoC knockout suggested the presence of additional functional azoreductases in this medically important bacterium. Overall, this study addresses a major gap in the literature by providing the first look, to our knowledge, at the complex physiology of C. perfringens upon azo dye exposure and the effect that both azo dyes and the azoreductase enzyme have on growth.

Synergistic effects of liquid and gas phase discharges using pulsed high voltage for dyes degradation in the presence of oxygen.

PubMed

Yang, Bin; Zhou, Minghua; Lei, Lecheng

2005-07-01

The technology of combined liquid and gas phase discharges (LGD) using pulsed high voltage for dyes degradation was developed in this study. Apparent synergistic effects for Acid orange II (AO) degradation in the presence of oxygen were observed. The enhancement of AO degradation rate was around 302%. Furthermore, higher energy efficiency was obtained comparing with individual liquid phase discharge (LD) or gas phase discharge process (GD). The AO degradation in the presence of oxygen by LGD proceeded through the direct ozone oxidation and the ozone decomposition induced by LD. Important operating parameters such as electrode distance, applied voltage, pulse repetition rate, and types of dyes were further investigated.

Evaluation of air-liquid interface exposure systems for in vitro ...

EPA Pesticide Factsheets

Exposure of cells to airborne pollutants at the air-liquid interface (ALI) is a more realistic approach than exposures of submerged cells. The published literature, however, describes irreproducible and/or unrealistic experimental conditions using ALI systems. We have compared five ALI systems for their ability to deliver both particulate matter (PM) and gases to cells cultured on porous membrane inserts. The ALI systems use different mechanisms to deliver pollutants to the inserts: diffusion, sedimentation, electrostatic precipitation (ESP), and thermophoresis (THP). We used fluorescent polystyrene latex spheres (PSLs) as a surrogate for PM to assess the efficacy of particle deposition in each system. PM loading in each insert was determined by dissolving the PSLs in ethyl acetate and measuring the fluorescence. Results show that using ESP as an external force enhances deposition of 50-nm PSLs by 5.5-fold and 11-fold for 1-µm PSLs when compared to diffusion alone. Similarly, THP enhances deposition of 50-nm and 1-µm PSLs by 4.5-fold and 2.7-fold, respectively. The interaction of ozone with an indigo dye on the surface of the insert showed that diffusion alone permitted gas-cell interaction. For each system there were various design and operational factors, such as the flow rate, surface materials and flow path geometry that adversely affected performance. Increased flow rates correlated with increased efficacy of the systems to deliver the gas to the inserts.

Development of a traveltime prediction equation for streams in Arkansas

USGS Publications Warehouse

Funkhouser, Jaysson E.; Barks, C. Shane

2004-01-01

During 1971 and 1981 and 2001 and 2003, traveltime measurements were made at 33 sample sites on 18 streams throughout northern and western Arkansas using fluorescent dye. Most measurements were made during steady-state base-flow conditions with the exception of three measurements made during near steady-state medium-flow conditions (for the study described in this report, medium-flow is approximately 100-150 percent of the mean monthly streamflow during the month the dye trace was conducted). These traveltime data were compared to the U.S. Geological Survey?s national traveltime prediction equation and used to develop a specific traveltime prediction equation for Arkansas streams. In general, the national traveltime prediction equation yielded results that over-predicted the velocity of the streams for 29 of the 33 sites measured. The standard error for the national traveltime prediction equation was 105 percent. The coefficient of determination was 0.78. The Arkansas prediction equation developed from a regression analysis of dye-tracing results was a significant improvement over the national prediction equation. This regression analysis yielded a standard error of 46 percent and a coefficient of determination of 0.74. The predicted velocities using this equation compared better to measured velocities. Using the variables in a regression analysis, the Arkansas prediction equation derived for the peak velocity in feet per second was: (Actual Equation Shown in report) In addition to knowing when the peak concentration will arrive at a site, it is of great interest to know when the leading edge of a contaminant plume will arrive. The traveltime of the leading edge of a contaminant plume indicates when a potential problem might first develop and also defines the overall shape of the concentration response function. Previous USGS reports have shown no significant relation between any of the variables and the time from injection to the arrival of the leading edge of the dye plume. For this report, the analysis of the dye-tracing data yielded a significant correlation between traveltime of the leading edge and traveltime of the peak concentration with an R2 value of 0.99. These data indicate that the traveltime of the leading edge can be estimated from: (Actual Equation Shown in Report)

Quantitative Determination of Four Azo Dyes in Rat Plasma with Solid-Phase Extraction and UFLC-MS-MS Analysis: Application to a Pharmacokinetic Study.

PubMed

Zhu, Hao; Huang, Changshun; Chen, Yijun; Lu, Zihui; Zhou, Haidong; Chen, Chunru; Wu, Jin; Chen, Xiaohong; Jin, Micong

2016-06-05

A rapid and sensitive ultra-fast liquid chromatography tandem mass spectrometry method, followed by simple protein precipitation and solid-phase extraction, has been developed and validated for the quantitative determination of four azo dyes (Para red, Solvent yellow 2, Solvent red 1 and Sudan red 7B) in rat plasma using D 5 -Sudan I as the internal standard. The optimal separation was accomplished on an Agilent Eclipse Plus C18 column (100 × 2.1 mm, 1.8 μm) with gradient elution using the mobile phase including acetonitrile and water (containing 0.1% formic acid). The flow rate was 0.45 mL/min. The detection was conducted by means of electrospray ionization mass spectrometry in positive ion mode with multiple reaction monitoring. The calibration curves showed good linearity, with correlation coefficients >0.998 for all of the analytes within the concentration range. The lower limits of quantification (LLOQs) of Para red, Solvent yellow 2, Solvent red 1 and Sudan red 7B in rat plasma were 1.0, 0.1, 0.1 and 0.1 μg/L, respectively. The intra- and interday relative standard deviations were ≤9.6 and ≤12.4%, respectively, and the accuracy was in the range of -5.8 to -9.5%. The average recoveries were between 81.49 and 118.65%, and the matrix effects were satisfactory in the biological matrices. The fully validated method has been successfully applied in measuring levels of the four azo dyes in rat plasma following oral administration of 20.0 mg/kg of analytes in rats, which was suitable for the pharmacokinetic studies of the azo dyes. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Flow cytometric detection of micronuclei by combined staining of DNA and membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wessels, J.M.; Nuesse, M.

1995-03-01

A new staining method is presented for flow cytometric measurement of micronuclei (MN) in cell cultures and human lymphocytes using membrane-specific fluorescent dyes in addition to DNA staining. Several combinations of fluorescent membrane and DNA dyes were studied for a better discrimination of MN from debris in a suspension of nuclei and micronuclei. For staining of membranes, the lipophilic dyes 2-hydroxyethyl-7,12,17-tris(methoxyethyl)porphycene (HEPn) and 1,6-diphenyl-1,3,5-hexatriene (DPH) were used in combination with ethidium bromide (EB), proflavine (PF), and Hoechst 33258 (HO). Due to their spectral properties, HO or EB combined with HEPn were not as suitable for the discrimination of MN frommore » debris as was HEPn in combination with PF. With HEPn in combination with PF, however, additional noise was found at low fluorescence intensities, probably due to free fluorescent dye molecules in the solution. The optimal simultaneous staining of membranes and DNA was obtained using a combination of DPH and EB. The induction of MN in Chinese hamster and mouse NIH-3T3 cells by UV-B illumination was studied with this new staining technique. UV-B illumination (280-360 nm) induced MN in both cell lines. Chinese hamster cells were found to be more sensitive to these wavelengths. Illumination with wavelengths above 360 nm did not induce MN in either cell line. The results obtained from human lymphocytes using the combination of EB or DPH were comparable to the results obtained with the combination of EB and HO. 23 refs., 7 figs.« less

An investigation of anthraquinone dye biodegradation by immobilized Aspergillus flavus in fluidized bed bioreactor.

PubMed

Andleeb, Saadia; Atiq, Naima; Robson, Geoff D; Ahmed, Safia

2012-06-01

Biodegradation and biodecolorization of Drimarene blue K(2)RL (anthraquinone) dye by a fungal isolate Aspergillus flavus SA2 was studied in lab-scale immobilized fluidized bed bioreactor (FBR) system. Fungus was immobilized on 0.2-mm sand particles. The reactor operation was carried out at room temperature and pH 5.0 in continuous flow mode with increasing concentrations (50, 100, 150, 200, 300, 500 mg l(-1)) of dye in simulated textile effluent on the 1st, 2nd, 5th, 8th, 11th, and 14th days. The reactors were run on fill, react, settle, and draw mode, with hydraulic retention time (HRT) of 24-72 h. Total run time for reactor operation was 17 days. The average overall biological oxygen demand (BOD), chemical oxygen demand (COD), and color removal in the FBR system were up to 85.57%, 84.70%, and 71.3%, respectively, with 50-mg l(-1) initial dye concentration and HRT of 24 h. Reductions in BOD and COD levels along with color removal proved that the mechanism of biodecolorization and biodegradation occurred simultaneously. HPLC and LC-MS analysis identified phthalic acid, benzoic acid, 1, 4-dihydroxyanthraquinone, 2,3-dihydro-9,10-dihydroxy-1,4-anthracenedione, and catechol as degradation products of Drimarene blue K(2)RL dye. Phytotoxicity analysis of bioreactor treatments provided evidence for the production of less toxic metabolites in comparison to the parent dye. The present fluidized bed bioreactor setup with indigenously isolated fungal strain in its immobilized form is efficiently able to convert the parent toxic dye into less toxic by-products.

Effect of nuclear vibrations, temperature, and orientation on injection and recombination conditions in amino-phenyl acid dyes on TiO2

NASA Astrophysics Data System (ADS)

Manzhos, Sergei; Segawa, Hiroshi; Yamashita, Koichi

2012-06-01

Adsorption geometry, nuclear vibrations, and molecular orientation of the dye with respect to the oxide surface affect significantly the performance of dye-sensitized solar cells. We compute the influence of these factors on injection and recombination conditions in organic amino-phenyl acid dyes differing by the donor group on the anatase (101) surface of titania. Nuclear motions affect significantly and differently between the dyes the driving force to injection Δ G. A temperature increase from 300 to 350 K does not have a noticeable effect on the distribution of injection rates in all studied system. Molecular dynamics simulations predict configurations in which dyes tend to lay flat on the oxide surface. The resulting proximity of the oxidation equivalent hole to the oxide is expected to promote recombination. Temporal evolution of the driving force to injection is found to be independent of dye orientation and uncorrelated to the oscillations of the Odye Ti bonds through which the dye is attached to the surface. We conclude that the dynamics of Δ G(t) is explained by uncorrelated evolution of the energies of the dye excited state and of the conduction band minimum of the oxide due to their respective vibrations. This suggests that it must be possible to control independently conditions of recombination (e.g. by preventing the dye oxidation hole from approaching TiO2 by using co-adsorbates) and of injection (e.g. by designing dyes where non-equilibrium geometries strongly destabilize dye's LUMO to increase Δ G).

Photocatalytic studies of electrochemically synthesized polysaccharide-functionalized ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Kaur, Simranjeet; Kaur, Harpreet

2018-05-01

The present work reports the electrochemical synthesis of polysaccharide-functionalized ZnO nanoparticles using sodium hydroxide, starch, and zinc electrodes for the degradation of cationic dye (Rhodamine-B) under sunlight. Physiochemical properties of synthesized sample have been characterized by different techniques such as XRD, TEM, FESEM, EDS, IR, and UV-visible spectroscopic techniques. The influence of various factors such as effect of dye concentration, contact time, amount of photocatalyst, and pH has been studied. The results obtained from the photodegradation study showed that degradation rate of Rhodamine-B dye has been increased with increase of amount of photocatalyst and decreased with increase in initial dye concentration. Furthermore, the kinetics of the degradation has been investigated. It has been found that the photodegradation of Rhodamine-B dye follows pseudo-first-order kinetics and prepared photocatalyst can effectively degrade the cationic dye. Thus, this ecofriendly and efficient photocatalyst can be used for the treatment of dye-contaminated water. This catalyst also showed the antibacterial activity against Bacillus pumilus and Escherichia coli bacterial strains, so the synthesized nanoparticles also have the pharmaceutical properties.

A Comparative Study on the Photophysics and Photochemistry of Xanthene Dyes in the Presence of Polyamidoamine (PAMAM) Dendrimers.

PubMed

Arbeloa, Ernesto Maximiliano; Previtali, Carlos Mario; Bertolotti, Sonia Graciela

2018-04-17

The photophysical and photochemical properties of the xanthene dyes Eosin Y, Erythrosin B, and Rose Bengal are evaluated in the presence of amino-terminated polyamidoamine (PAMAM) dendrimers of relatively high generation (G3-G5) in alkaline aqueous solution. UV/Vis absorption and fluorescence spectra of the dyes show bathochromic shifts, which correlate with the size of the dendrimer. Binding constants (K bind ) are calculated from absorption data. The resulting high K bind values indicate strong interactions between both molecules. Triplet-triplet absorption spectra of the dyes are recorded by laser flash photolysis, and a decrease in the triplet lifetimes is observed in the presence of dendrimers. At the same time, an increase in the absorption of the semireduced form of the dyes is observed. Rate constants for triplet quenching ( 3 k q ) and radical quantum yields (Φ R ) are obtained. The results are explained by a very efficient electron-transfer process from PAMAM to xanthene dyes for all of the dye/dendrimer couples that are evaluated. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Water treatment: A scalable graphene-based membrane

DOE PAGES

Vlassiouk, Ivan V.

2017-08-28

We discuss how an improved industrial manufacturability has been achieved for a hybrid water-treatment membrane that exhibits high water permeance, prolonged high salt and dye rejection under cross-flow conditions and better resistance to chlorine treatment.

Water treatment: A scalable graphene-based membrane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vlassiouk, Ivan V.

We discuss how an improved industrial manufacturability has been achieved for a hybrid water-treatment membrane that exhibits high water permeance, prolonged high salt and dye rejection under cross-flow conditions and better resistance to chlorine treatment.

Fluorescent Cell Barcoding for Multiplex Flow Cytometry

PubMed Central

Krutzik, Peter O.; Clutter, Matthew R.; Trejo, Angelica; Nolan, Garry P.

2011-01-01

Fluorescent Cell Barcoding (FCB) enables high throughput, i.e. high content flow cytometry by multiplexing samples prior to staining and acquisition on the cytometer. Individual cell samples are barcoded, or labeled, with unique signatures of fluorescent dyes so that they can be mixed together, stained, and analyzed as a single sample. By mixing samples prior to staining, antibody consumption is typically reduced 10 to 100-fold. In addition, data robustness is increased through the combination of control and treated samples, which minimizes pipetting error, staining variation, and the need for normalization. Finally, speed of acquisition is enhanced, enabling large profiling experiments to be run with standard cytometer hardware. In this unit, we outline the steps necessary to apply the FCB method to cell lines as well as primary peripheral blood samples. Important technical considerations such as choice of barcoding dyes, concentrations, labeling buffers, compensation, and software analysis are discussed. PMID:21207359

In vitro interactions between splenocytes and dansylamide dye-embedded nanoparticles detected by flow cytometry

PubMed Central

Nyland, Jennifer F.; Bai, Jennifer J. K.; Katz, Howard E.; Silbergeld, Ellen K.

2009-01-01

Engineered nanoparticles (NPs) possess a range of biological activity. In vitro methods for assessing toxicity and efficacy would be enhanced by simultaneous quantitative information on the behavior of NPs in culture systems and signals of cell response. We have developed a method for visualizing NPs within cells using standard flow cytometric techniques and uniquely designed spherical siloxane NPs with an embedded (covalently bound) dansylamide dye. This method allowed NP visualization without obscuring detection of relevant biomarkers of cell subtype, activation state, and other events relevant to assessing bioactivity. We determined that NPs penetrated cells and induced a range of biological signals consistent with activation and costimulation. These results indicate that NPs may affect cell function at concentrations below those inducing cytotoxicity or apoptosis and demonstrate a novel method to image both localization of NPs and cell-level effects. PMID:19523425

Time of travel of solutes in selected reaches of the Sandusky River Basin, Ohio, 1972 and 1973

USGS Publications Warehouse

Westfall, Arthur O.

1976-01-01

A time of travel study of a 106-mile (171-kilometer) reach of the Sandusky River and a 39-mile (63-kilometer) reach of Tymochtee Creek was made to determine the time required for water released from Killdeer Reservoir on Tymochtee Creek to reach selected downstream points. In general, two dye sample runs were made through each subreach to define the time-discharge relation for approximating travel times at selected discharges within the measured range, and time-discharge graphs are presented for 38 subreaches. Graphs of dye dispersion and variation in relation to time are given for three selected sampling sites. For estimating travel time and velocities between points in the study reach, tables for selected flow durations are given. Duration curves of daily discharge for four index stations are presented to indicate the lo-flow characteristics and for use in shaping downward extensions of the time-discharge curves.

Infra-red technique for cerebral blood flow: comparison with /sup 133/Xenon clearance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colacino, J.M.; Grubb, B.; Joebsis, F.F.

A rapid infra-red optical technique has been developed for the measurement of cerebral blood flow. The method measures optical density changes across the intact skull during the passage of a bolus of the dye. Cardio-Green (CG). The clearance curves obtained for CG boluses are very short (less than 30 sec) in comparison with those obtained with tracers such as /sup 133/Xenon (10-30 min) that distribute into cerebral tissue. The volume of distribution of CG is totally intravascular, and the dye is relatively slowly cleared from the body. The important advantages of this spectrophotometric technique are its speed, versatility, and themore » avoidance of radioactive materials. The differential spectrophotometer used in this study, with trivial modifications, has been used to monitor changes in brain blood volume, oxygen saturation of hemoglobin, and cortical mitochondrial respiratory function, which illustrate the versatility of the technique for neurological assessments.« less

Determination of equilibrium and rate constants for complex formation by fluorescence correlation spectroscopy supplemented by dynamic light scattering and Taylor dispersion analysis.

PubMed

Zhang, Xuzhu; Poniewierski, Andrzej; Jelińska, Aldona; Zagożdżon, Anna; Wisniewska, Agnieszka; Hou, Sen; Hołyst, Robert

2016-10-04

The equilibrium and rate constants of molecular complex formation are of great interest both in the field of chemistry and biology. Here, we use fluorescence correlation spectroscopy (FCS), supplemented by dynamic light scattering (DLS) and Taylor dispersion analysis (TDA), to study the complex formation in model systems of dye-micelle interactions. In our case, dyes rhodamine 110 and ATTO-488 interact with three differently charged surfactant micelles: octaethylene glycol monododecyl ether C 12 E 8 (neutral), cetyltrimethylammonium chloride CTAC (positive) and sodium dodecyl sulfate SDS (negative). To determine the rate constants for the dye-micelle complex formation we fit the experimental data obtained by FCS with a new form of the autocorrelation function, derived in the accompanying paper. Our results show that the association rate constants for the model systems are roughly two orders of magnitude smaller than those in the case of the diffusion-controlled limit. Because the complex stability is determined by the dissociation rate constant, a two-step reaction mechanism, including the diffusion-controlled and reaction-controlled rates, is used to explain the dye-micelle interaction. In the limit of fast reaction, we apply FCS to determine the equilibrium constant from the effective diffusion coefficient of the fluorescent components. Depending on the value of the equilibrium constant, we distinguish three types of interaction in the studied systems: weak, intermediate and strong. The values of the equilibrium constant obtained from the FCS and TDA experiments are very close to each other, which supports the theoretical model used to interpret the FCS data.

High-speed off-axis holographic cinematography with a copper-vapor-pumped dye laser.

PubMed

Lauterborn, W; Judt, A; Schmitz, E

1993-01-01

A series of coherent light pulses is generated by pumping a dye laser with the pulsed output of a copper-vapor laser at rates of as much as 20 kHz. Holograms are recorded at this pulse rate on a rotating holographic plate. This technique of high-speed holographic cinematography is demonstrated by viewing the bubble filaments that appear in water under the action of a sound field of high intensity.

Using nonlinear ac electrokinetics vortex flow to enhance catalytic activities of sol-gel encapsulated trypsin in microfluidic devices

PubMed Central

Wang, Shau-Chun; Chen, Hsiao-Ping; Lai, Yi-Wen; Chau, Lai-Kwan; Chuang, Yu-Chun; Chen, Yi-Jie

2007-01-01

A novel microstirring strategy is applied to accelerate the digestion rate of the substrate Nα-benzoyl-L-arginine-4-nitroanilide (L-BAPA) catalyzed by sol-gel encapsulated trypsin. We use an ac nonlinear electrokinetic vortex flow to stir the solution in a microfluidic reaction chamber to reduce the diffusion length between the immobilized enzyme and substrate in the solution. High-intensity nonlinear electroosmotic microvortices, with angular speeds in excess of 1 cm∕s, are generated around a small (∼1.2 mm) conductive ion exchange granule when ac electric fields (133 V∕cm) are applied across a miniature chamber smaller than 10 μl. Coupling between these microvortices and the on-and-off electrophoretic motion of the granule in low frequency (0.1 Hz) ac fields produces chaotic stream lines to stir substrate molecules sufficiently. We demonstrate that, within a 5-min digestion period, the catalytic reaction rate of immobilized trypsin increases almost 30-fold with adequate reproducibility (15%) due to sufficient stirring action through the introduction of the nonlinear electrokinetic vortices. In contrast, low-frequency ac electroosmotic flow without the granule, provides limited stirring action and increases the reaction rate approximately ninefold with barely acceptable reproducibility (30%). Dye molecules are used to characterize the increases in solute diffusivity in the reaction reservoir in which sol-gel particles are placed, with and without the presence of granule, and compared with the static case. The solute diffusivity enhancement data show respective increases of ∼30 and ∼8 times, with and without the presence of granule. These numbers are consistent with the ratios of the enhanced reaction rate. PMID:19693360

Using nonlinear ac electrokinetics vortex flow to enhance catalytic activities of sol-gel encapsulated trypsin in microfluidic devices.

PubMed

Wang, Shau-Chun; Chen, Hsiao-Ping; Lai, Yi-Wen; Chau, Lai-Kwan; Chuang, Yu-Chun; Chen, Yi-Jie

2007-09-04

A novel microstirring strategy is applied to accelerate the digestion rate of the substrate N(alpha)-benzoyl-L-arginine-4-nitroanilide (L-BAPA) catalyzed by sol-gel encapsulated trypsin. We use an ac nonlinear electrokinetic vortex flow to stir the solution in a microfluidic reaction chamber to reduce the diffusion length between the immobilized enzyme and substrate in the solution. High-intensity nonlinear electroosmotic microvortices, with angular speeds in excess of 1 cms, are generated around a small ( approximately 1.2 mm) conductive ion exchange granule when ac electric fields (133 Vcm) are applied across a miniature chamber smaller than 10 mul. Coupling between these microvortices and the on-and-off electrophoretic motion of the granule in low frequency (0.1 Hz) ac fields produces chaotic stream lines to stir substrate molecules sufficiently. We demonstrate that, within a 5-min digestion period, the catalytic reaction rate of immobilized trypsin increases almost 30-fold with adequate reproducibility (15%) due to sufficient stirring action through the introduction of the nonlinear electrokinetic vortices. In contrast, low-frequency ac electroosmotic flow without the granule, provides limited stirring action and increases the reaction rate approximately ninefold with barely acceptable reproducibility (30%). Dye molecules are used to characterize the increases in solute diffusivity in the reaction reservoir in which sol-gel particles are placed, with and without the presence of granule, and compared with the static case. The solute diffusivity enhancement data show respective increases of approximately 30 and approximately 8 times, with and without the presence of granule. These numbers are consistent with the ratios of the enhanced reaction rate.

Near-infrared indocyanine dye permits real-time characterization of both venous and lymphatic circulation

NASA Astrophysics Data System (ADS)

Kurahashi, Toshikazu; Iwatsuki, Katsuyuki; Onishi, Tetsuro; Arai, Tetsuya; Teranishi, Katsunori; Hirata, Hitoshi

2016-08-01

We investigated the optical properties of a near-infrared (NIR) fluorochrome, di-β-cyclodextrin-binding indocyanine derivative (TK-1), and its pharmacokinetic differences with indocyanine green (ICG). TK-1 was designed to have hydrophilic cyclodextrin molecules and, thus, for higher water solubility and smaller particle sizes than the plasma protein-bound ICG. We compared optical properties such as the absorption and fluorescence spectra, quantum yield, and photostability between both dyes in vitro. In addition, we subcutaneously injected a 1 mM solution of TK-1 or ICG into the hind footpad of rats and observed real-time NIR fluorescence intensities in their femoral veins and accompanying lymphatics at the exposed groin site to analyze the dye pharmacokinetics. These optical experiments demonstrated that TK-1 has high water solubility, a low self-aggregation tendency, and high optical and chemical stabilities. Our in vivo imaging showed that TK-1 was transported via peripheral venous flow and lymphatic flow, whereas ICG was drained only through lymphatics. The results of this study showed that lymphatic and venous transport can be differentially regulated and is most likely influenced primarily by particle size, and that TK-1 can enable real-time NIR fluorescence imaging of whole fluids and solute movement via both microvessels and lymphatics, which conventional ICG cannot achieve.

Thermogravimetric analysis of co-combustion between microalgae and textile dyeing sludge.

PubMed

Peng, Xiaowei; Ma, Xiaoqian; Xu, Zhibin

2015-03-01

The synergistic interaction and kinetics of microalgae, textile dyeing sludge and their blends were investigated under combustion condition by thermogravimetric analysis. The textile dyeing sludge was blended with microalgae in the range of 10-90wt.% to investigate their co-combustion behavior. Results showed that the synergistic interaction between microalgae and textile dyeing sludge improved the char catalytic effect and alkali metals melt-induced effect on the decomposition of textile dyeing sludge residue at high temperature of 530-800°C. As the heating rate increasing, the entire combustion process was delayed but the combustion intensity was enhanced. The lowest average activation energy was obtained when the percentage of microalgae was 60%, which was 227.1kJ/mol by OFW and 227.4kJ/mol by KAS, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of time on dyeing wastewater treatment

NASA Astrophysics Data System (ADS)

Ye, Tingjin; Chen, Xin; Xu, Zizhen; Chen, Xiaogang; Shi, Liang; He, Lingfeng; Zhang, Yongli

2018-03-01

The preparation of carboxymethylchitosan wrapping fly-ash adsorbent using high temperature activated fly ash and sodium carboxymethyl chitosan (CWF), as with the iron-carbon micro-electrolysis process simulation and actual printing and dyeing wastewater. The effects of mixing time and static time on decolorization ratio, COD removing rate and turbidness removing rate were investigated. The experimental results show that the wastewater stirring times on the decolorization rate and COD removal rate and turbidity removal rate influence, with increasing of the stirring time, three showed a downward trend, and reached the peak at 10 min time; wastewater time on the decolorization ratio and COD removing efficiency and turbidness removing rate influence, along with standing time increase, three who declined and reached the maximum in 30min time.

Carbon composite lignin-based adsorbents for the adsorption of dyes.

PubMed

Wang, Xiaohong; Jiang, Chenglong; Hou, Bingxia; Wang, Yingying; Hao, Chen; Wu, Jingbo

2018-05-10

Carbon composite lignin-based adsorbent were prepared through hydrothermal method with glucose as carbon source, calcium lignosulfonate and triethylene tetramine as raw materials, respectively. The optimum synthesis conditions were determined by investigating the addition of carbon and triethylene tetramine. The adsorbent was used for the adsorption of azo dyes Congo red and Eriochrome blue black R, and the five factors affecting the adsorption were discussed, including pH of dyes, initial concentration, adsorption time, adsorption temperature and adsorbent dosage. The corresponding adsorption mechanism such as pseudo first order kinetics, pseudo second order kinetics, intraparticle diffusion, Langmuir adsorption isotherm, Freundlich isotherm, Temkin isotherm, Dubinin-Radushkevich adsorption isotherm, thermodynamics were also studied. When the dye concentration is 40 mg L -1 , Congo red and Eriochrome blue black R dye removal rates reach 99%. Moreover, the adsorption process of two kinds of dyes follow the pseudo second order kinetics and the Langmuir adsorption isotherm. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhanced optical, thermal and piezoelectric behavior in dye doped potassium acid phthalate (KAP) single crystal

NASA Astrophysics Data System (ADS)

Rao, G. Babu; Rajesh, P.; Ramasamy, P.

2017-06-01

Dye inclusion crystals have attracted researchers in the context of crystal growth for applications in solid state lasers. Pure and 0.1 mol% amaranth doped KAP single crystals, were grown from aqueous solutions by slow evaporation technique at room temperature. The grown crystals are up to the dimension of 12×10×3 mm3. Attempt is made to improve the growth rate, optical, piezoelectric and photoconductive properties of pure KAP single crystal with addition of amaranth dye as a dopant. Various characterization studies were made for both pure and dye doped KAP. Thermal stability of the crystals is tested from thermogravimetric and differential thermal analysis (TG/DTA). There is only one endothermic peak indicating decomposition point. Higher optical transparency for dye doped KAP crystal was identified from the UV-vis spectrum. Etching studies showed an improvement in the optical quality of the KAP crystal after doping with amaranth dye. The positive photoconductive nature is observed from both pure and amaranth doped KAP.

Parameters affecting the photocatalytic degradation of dyes using TiO2: a review

NASA Astrophysics Data System (ADS)

Reza, Khan Mamun; Kurny, ASW; Gulshan, Fahmida

2017-07-01

Traditional chemical, physical and biological processes for treating wastewater containing textile dye have such disadvantages as high cost, high energy requirement and generation of secondary pollution during treatment process. The advanced oxidation processes technology has been attracting growing attention for the decomposition of organic dyes. Such processes are based on the light-enhanced generation of highly reactive hydroxyl radicals, which oxidize the organic matter in solution and convert it completely into water, CO2 and inorganic compounds. In this presentation, the photocatalytic degradation of dyes in aqueous solution using TiO2 as photocatalyst under solar and UV irradiation has been reviewed. It is observed that the degradation of dyes depends on several parameters such as pH, catalyst concentration, substrate concentration and the presence of oxidants. Reaction temperature and the intensity of light also affect the degradation of dyes. Particle size, BET-surface area and different mineral forms of TiO2 also have influence on the degradation rate.

Spectral-Polarization Properties and Light Resistance of Polyvinyl-Alcohol Films Colored With Disazo Dyes

NASA Astrophysics Data System (ADS)

Fillipovich, L. N.; Ariko, N. G.; Agabekov, V. E.; Malashko, P. M.

2005-09-01

Polarizers containing disazo dyes from the group of azobenzene-azonaphthalene have been developed. It has been established that their polarizing ability is determined by the mutual disposition of the azo group and electron-donor substituents in the naphthalene ring. On diazo coupling of γ acid into the α position relative to the oxy group, the M1 and M3 dyes are formed, the polarizing ability of which in uniaxially oriented polyvinyl-alcohol films is higher than in the M2 dye produced as a result of diazo coupling into the α position relative to the amino group. On irradiation by UV light, the dyes are subjected to photodestruction, which, in the case of M2, proceeds through trans-cis-isomerization. The rate of photodestruction depends on the aggregation of the dye molecules, and it increases in the presence of a free-radical initiator. The UV absorber (substituted benzotriazole) and the uniaxial orientation of the film retard this process.

Color film preservation system: Breadboard development

NASA Technical Reports Server (NTRS)

1984-01-01

The development of an economically feasible system to prevent and/or substantially reduce the degradation of the color dyes of the retinal reflex images recorded on color slide films is discussed. Three different types of film storage systems were designed, fabricated, and tested. An extruded plastic cylindrical container was pressurized and no observable leakage occurred, indicating that long term storage is possible. An operational breadboard was fabricated. The system offers the capability to determine purging requirements to achieve various levels of oxygen concentration and precise leakage of various container configurations. The system has digitial display of oxygen content of the container, automatic control of the oxygen content as well as of the container to atmosphere pressure differential, and flow rate readout during purging.

Preparation of monodisperse PEG hydrogel composite microspheres via microfluidic chip with rounded channels

NASA Astrophysics Data System (ADS)

Yu, Bing; Cong, Hailin; Liu, Xuesong; Ren, Yumin; Wang, Jilei; Zhang, Lixin; Tang, Jianguo; Ma, Yurong; Akasaka, Takeshi

2013-09-01

An effective microfluidic method to fabricate monodisperse polyethylene glycol (PEG) hydrogel composite microspheres with tunable dimensions and properties is reported in this paper. A T-junction microfluidic chip equipped with rounded channels and online photopolymerization system is applied for the microsphere microfabrication. The shape and size of the microspheres are well controlled by the rounded channels and PEG prepolymer/silicon oil flow rate ratios. The obtained PEG/aspirin composite microspheres exhibit a sustained release of aspirin for a wide time range; the obtained PEG/Fe3O4 nanocomposite microspheres exhibit excellent magnetic properties; and the obtained binary PEG/dye composite microspheres show the ability to synchronously load two functional components in the same peanut-shaped or Janus hydrogel particles.

Retinal vein occlusion

MedlinePlus

... of one eye. Exams and Tests Tests to evaluate for vein occlusion include: Exam of the retina after dilating the pupil An eye test that uses a special dye and camera to look at blood flow in the retina and choroid. Intraocular pressure Pupil ...

High Affinity Macrocycle Threading by a Near-Infrared Croconaine Dye with Flanking Polymer Chains

PubMed Central

Liu, Wenqi; Peck, Evan M.; Smith, Bradley D.

2016-01-01

Croconaine dyes have narrow and intense absorption bands at ~800 nm, very weak fluorescence, and high photostabilities, which combine to make them very attractive chromophores for absorption-based imaging or laser heating technologies. The physical supramolecular properties of croconaine dyes have rarely been investigated, especially in water. This study focuses on a molecular threading process that encapsulates a croconaine dye inside a tetralactam macrocycle in organic or aqueous solvent. Macrocycle association and rate constant data are reported for a series of croconaine structures with different substituents attached to the ends of the dye. The association constants were highest in water (Ka ~109 M−1), and the threading rate constants (kon) increased in the solvent order H2O > MeOH > CHCl3. Systematic variation of croconaine substituents located just outside the croconaine/macrocycle complexation interface hardly changed Ka but had a strong influence on kon. A croconaine dye with N-propyl groups at each end of the structure exhibited a desirable mixture of macrocycle threading properties; that is, there was rapid and quantitative croconaine/macrocycle complexation at relatively high concentrations in water, and no dissociation of the pre-assembled complex when it was diluted into a solution of fetal bovine serum, even after laser induced photothermal heating of the solution. The combination of favorable near-infrared absorption properties and tunable mechanical stability makes threaded croconaine/macrocycle complexes very attractive as molecular probes or as supramolecular composites for various applications in absorption-based imaging or photothermal therapy. PMID:26807599

Thermographic Data Analyses for Karst Watersheds

NASA Technical Reports Server (NTRS)

Campbell, C. Warren; McCaleb, Rebecca C. (Technical Monitor)

2001-01-01

Aerial thermography is an emerging technology unsurpassed for locating groundwater discharges. Thermography can be used to locate submerged discharges that are extremely difficult to find by other means. In two large projects, thermography was used to identify almost every significant spring at sites underlain by karst aquifers. This technology effectively converts Brown's Type 5 topology to types 1 or 2 (all discharges known), which has a significant impact on dye tracing. At a north Alabama site, springs located by thermography quadrupled the known groundwater discharge in and around the site. For submerged discharges, thermographic temperatures can be measured down the center of the groundwater plume that rises to the surface in the winter. Using the Cornell Mixing (CORMIX) model, flow rate for one submerged spring was estimated. Once identified, estimates of spring recharge area were desired. The size of the area of recharge was estimated by hydrograph separation of flow data from nearby, unregulated surface streams. Monthly recharge estimates were also made and used to show that in north Alabama the mean annual recharge/discharge occurs during May and December. Spring flow measurements for the same county of north Alabama were averaged to obtain mean flows. Then measurements for May only, were averaged. The two averages usually agreed to within 20 percent. This provides evidence that hydrograph separation determinations of recharge are valid.

Transport of Brownian spheroidal nanoparticles in near-wall vascular flows for cancer therapy

NASA Astrophysics Data System (ADS)

Lin, Tiras Y.; Shah, Preyas N.; Smith, Bryan R.; Shaqfeh, Eric S. G.

2016-11-01

The microenvironment local to a tumor is characterized by a leaky vasculature induced by angiogenesis from tumor growth. Small pores form in the blood vessel walls, and these pores provide a pathway for cancer-ameliorating nanoparticle drug carriers. Using both simulations and microfluidics experiments, we investigate the extravasation of nanoparticles through pores. Using Brownian dynamics simulations, we evolve the stochastic equations for both point particles and finite-size spheroids of varying aspect ratio. We investigate the effect of wall shear flow and pore suction flow (Sampson flow) on the extravasation process. We consider pores of two types: physiologically relevant short pores with a length equal to the particle size and long pores which are relevant to diffusion through membranes. Additionally, we perform microfluidics experiments in which the extravasation rates of various nanoparticles tagged with fluorescent dye through pores are measured. In particular, using fluorometry we measure the flux of nanoparticles across a track-etched membrane, which separates two chambers. Our preliminary results indicate that the flux measured from experiment agrees reasonably with the simulations done with long pores, and we discuss the effect of pore length on extravasation. T.Y.L. is supported by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.

Photoactive dye enhanced tissue ablation for endoscopic laser prostatectomy

NASA Astrophysics Data System (ADS)

Ahn, Minwoo; Nguyen, Trung Hau; Nguyen, Van Phuc; Oh, Junghwan; Kang, Hyun Wook

2015-02-01

Laser light has been widely used as a surgical tool to treat benign prostate hyperplasia with high laser power. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue ablation with low laser power. The experiment was implemented on chicken breast due to minimal optical absorption Amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532-nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm2. Light absorbance and ablation threshold were measured with UV-VIS spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye-injection was evaluated in light of radiant exposure, dye concentration, and number of injection. Higher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with input parameter. Among the dyes, AR created the highest ablation rate of 44.2+/-0.2 μm/pulse due to higher absorbance and lower ablation threshold. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33 % reduced laser power with almost equivalent performance. In-depth comprehension on photoactive dye-enhanced tissue ablation can help accomplish efficient and safe laser treatment for BPH with low power application.

Enzyme-mediated bacterial biodegradation of an azo dye (C.I. Acid blue 113): reuse of treated dye wastewater in post-tanning operations.

PubMed

Senthilvelan, T; Kanagaraj, J; Panda, R C

2014-11-01

"Dyeing" is a common practice used to color the hides during the post-tanning operations in leather processing generating plenty of wastewater. The waste stream containing dye as pollutant is severely harmful to living beings. An azo dye (C.I. Acid Blue 113) has been biodegraded effectively by bacterial culture mediated with azoreductase enzyme to reduce the pollution load in the present investigation. The maximum rate of dye degradation was found to be 96 ± 4 and 92 ± 4 % for the initial concentrations of 100 and 200 mg/l, respectively. The enzyme activity was measured using NADH as a substrate. Fourier transform infrared spectroscopy (FT-IR) analysis was confirmed that the transformation of azo linkage could be transformed into N2 or NH3 or incorporated into complete biomass. Breaking down of dye molecules to various metabolites (such as aniline, naphthalene-1,4-diamine, 3-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid, 8-aminonaphthalene-1-sulfonic acid, 5,8-diaminonaphthalene-1-sulfonic acid) was confirmed by gas chromatography and mass spectra (GC-MS) and mass (electrospray ionization (ESI)) spectra analysis. The treated wastewater could be reused for dyeing operation in the leather processing, and the properties of produced leather were evaluated by conventional methods that revealed to have improved dye penetration into the grain layer of experimental leather sample and resulted in high levelness of dyeing, which helps to obtain the desired smoothness and soft leather properties.

An All-Solid-State High Repetiton Rate Titanium:Sapphire Laser System For Resonance Ionization Laser Ion Sources

NASA Astrophysics Data System (ADS)

Mattolat, C.; Rothe, S.; Schwellnus, F.; Gottwald, T.; Raeder, S.; Wendt, K.

2009-03-01

On-line production facilities for radioactive isotopes nowadays heavily rely on resonance ionization laser ion sources due to their demonstrated unsurpassed efficiency and elemental selectivity. Powerful high repetition rate tunable pulsed dye or Ti:sapphire lasers can be used for this purpose. To counteract limitations of short pulse pump lasers, as needed for dye laser pumping, i.e. copper vapor lasers, which include high maintenance and nevertheless often only imperfect reliability, an all-solid-state Nd:YAG pumped Ti:sapphire laser system has been constructed. This could complement or even replace dye laser systems, eliminating their disadvantages but on the other hand introduce shortcomings on the side of the available wavelength range. Pros and cons of these developments will be discussed.

Photocatalytic degradation of model textile dyes in wastewater using ZnO as semiconductor catalyst.

PubMed

Chakrabarti, Sampa; Dutta, Binay K

2004-08-30

Semiconductor photocatalysis often leads to partial or complete mineralization of organic pollutants. Upon irradiation with UV/visible light, semiconductors catalyze redox reactions in presence of air/O2 and water. Here, the potential of a common semiconductor, ZnO, has been explored as an effective catalyst for the photodegradation of two model dyes: Methylene Blue and Eosin Y. A 16 W lamp was the source of UV-radiation in a batch reactor. The effects of process parameters like, catalyst loading, initial dye concentration, airflow rate, UV-radiation intensity, and pH on the extent of photo degradation have been investigated. Substantial reduction of COD, besides removal of colour, was also achieved. A rate equation for the degradation based on Langmuir-Hinshelwood model has been proposed.

Optimization and enhancement of textile reactive Remazol black B decolorization and detoxification by environmentally isolated pH tolerant Pseudomonas aeruginosa KY284155.

PubMed

Hashem, Rasha A; Samir, Reham; Essam, Tamer M; Ali, Amal E; Amin, Magdy A

2018-05-21

Azo dyes are complex derivatives of diazene used in food and textile manufacture. They are highly recalcitrant compounds, and account for severe environmental and health problems. Different strains of Pseudomonas species were isolated from textile wastewater effluents. The bioconversion of Remazol black B (a commonly used water soluble dye) by Pseudomonas aeruginosa was observed in static conditions. The bio-decolorization process was optimized by a multi factorial Plackett-Burman experimental design. Decolorization of 200 mg L -1 reached 100% in 32 h. Interestingly, the presence of yeast extract, magnesium and iron in the culture media, highly accelerated the rate of decolorization. Moreover, one of our isolates, P. aeruginosa KY284155, was kept high degradation rates at high pH (pH = 9), which represents the pH of most textile wastewater effluents, and was able to tolerate high concentration of dye up to 500 mg L -1 . In bacteria, azo-dye degradation is often initiated by reductive azo compound cleavage catalyzed by azo-reductases. Three genes encoding azo-reductases, paazoR1, paazoR2 and paazoR3, could be identified in the genome of the isolated P. aeruginosa stain (B1). Bioinformatics analyses of the paazoR1, paazoR2 and paazoR3 genes reveal their prevalence and conservation in other P. aeruginosa strains. Chemical oxygen demand dramatically decreased and phyto-detoxification of the azo dye was accomplished by photocatalytic post treatment of the biodegradation products. We suggest applying combined biological photocatalytic post treatment for azo dyes on large scale, for effective, cheap decolorization and detoxification of azo-dyes, rendering them safe enough to be discharged in the environment.

Structure and reactivity of thiazolium azo dyes: UV-visible, resonance Raman, NMR, and computational studies of the reaction mechanism in alkaline solution.

PubMed

Abbott, Laurence C; Batchelor, Stephen N; Moore, John N

2013-03-07

UV-visible absorption, resonance Raman, and (1)H NMR spectroscopy, allied with density functional theory (DFT) calculations, have been used to study the structure, bonding, and alkaline hydrolysis mechanism of the cationic thiazloium azo dye, 2-[2-[4-(diethylamino)phenyl]diazenyl]-3-methyl-thiazolium (1a), along with a series of six related dyes with different 4-dialkylamino groups and/or other phenyl ring substituents (2a-c, 3a-c) and the related isothiazolium azo dye, 5-[2-[4-(dimethylamino)phenyl]diazenyl]-2-methyl-isothiazolium (4). These diazahemicyanine dyes are calculated to have a similar low-energy structure that is cis, trans at the (iso)thiazolium-azo group, and for which the calculated Raman spectra provide a good match with the experimental data; the calculations on these structures are used to assign and discuss the transitions giving rise to the experimental spectra, and to consider the bonding and its variation between the dyes. UV-visible, Raman, and NMR spectra recorded from minutes to several weeks after raising the pH of an aqueous solution of 1a to ca. 11.5 show that the dominant initial step in the reaction is loss of diethylamine to produce a quinonimine (ca. hours), with subsequent reactions occurring on longer time scales (ca. days to weeks); kinetic analyses give a rate constant of 2.6 × 10(-2) dm(3) mol(-1) s(-1) for reaction of 1a with OH(-). UV-visible spectra recorded on raising the pH of the other dyes in solution show similar changes that are attributed to the same general reaction mechanism, but with different rate constants for which the dependence on structure is discussed.

Decolorization of Mordant red 73 azo dye in water using H2O2/UV and photo-Fenton treatment.

PubMed

Elmorsi, Taha M; Riyad, Yasser M; Mohamed, Zeinhom H; Abd El Bary, Hassan M H

2010-02-15

Decolorization of the Mordant red 73 (MR73) azo dye in water was investigated in laboratory-scale experiments using UV/H(2)O(2) and photo-Fenton treatments. Photodegradation experiments were carried out in a stirred batch photoreactor equipped with a low-pressure mercury lamp as UV source at 254 nm. The effect of operating parameters such as pH, [H(2)O(2)](,) [dye] and the presence of inorganic salts (NaNO(3), NaCl and Na(2)CO(3)) were also investigated. The results indicated that complete dye decolorization was obtained in less than 60 min under optimum conditions. Furthermore, results showed that dye degradation was dependent upon pH, [H(2)O(2)] and initial dye concentration. The presence of chloride ion led to large decreases in the photodegradation rate of MR73 while both nitrate and carbonate ions have a slight effect. The photo-Fenton treatment, in the presence of Fe powder as a source of Fe(2+) ions, was highly efficient and resulted in 99% decolorization of the dye in 15 min. Mineralization of MR73 dye was investigated by determining chemical oxygen demand (COD). In a 3h photoperiod "65%" of the dye was mineralized by the H(2)O(2)/UV process, while the photo-Fenton treatment was more efficient producing 85% mineralization over the same 3-h period.

Modulation of π-spacer of carbazole-carbazole based organic dyes toward high efficient dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Chitpakdee, Chirawat; Jungsuttiwong, Siriporn; Sudyoadsuk, Taweesak; Promarak, Vinich; Kungwan, Nawee; Namuangruk, Supawadee

2017-03-01

The effects of type and position of π-linker in carbazole-carbazole based dyes on their performance in dye-sensitized solar cells (DSSCs) were investigated by DFT and TDDFT methods. The calculated electronic energy level, electron density composition, charge injection and charge recombination properties were compared with those of the high performance CCT3A dye synthesized recently. It is found that that mixing a benzothiadizole (B) unit with two thiophene (T) units in the π-spacer can greatly shift absorption wavelength to near infrared region and enhance the light harvesting efficiency (LHE) resulting in increasing of short-circuit current density (Jsc), whereas a thienothiophene unit does not affect those properties. However, a B should be not directly connected to the anchoring group of the dye because it brings electrolyte to the TiO2 surface which may increase charge recombination rate and consequently decrease open circuit voltage (Voc). This work shows how type and position of the π-linker affect the performance of DSSCs, and how to modulate those properties. We predicted that the designed dye derived from insertion of the B unit in between the two T units would have higher performance than CCT3A dye. The insight understanding from this study is useful for further design of higher performance dyes by molecular engineering.

Ultrasonic enhancement of the simultaneous removal of quaternary toxic organic dyes by CuO nanoparticles loaded on activated carbon: Central composite design, kinetic and isotherm study.

PubMed

Dashamiri, Somayeh; Ghaedi, Mehrorang; Dashtian, Kheibar; Rahimi, Mahmood Reza; Goudarzi, Alireza; Jannesar, Ramin

2016-07-01

Copper oxide nanoparticles loaded on activated carbon (CuO-NPs-AC) were prepared and fully analyzed and characterized with FE-SEM, XRD and FT-IR. Subsequently, this novel material was used for simultaneous ultrasound-assisted adsorption of brilliant green (BG), auramine O (AO), methylene blue (MB) and eosin yellow (EY) dyes. Problems regard to dyes spectra overlap in quaternary solution of this dyes were omitted by derivative spectrophotometric method. The best pH in quaternary system was studied by using one at a time method to achieved maximum dyes removal percentage. Subsequently, sonication time, adsorbent dosage and initial dyes concentrations influence on dyes removal was optimized by central composite design (CCD) combined with desirability function approach (DFA). Desirability score of 0.978 show optimum conditions set at sonication time (4.2 min), adsorbent mass (0.029 g), initial dyes concentration (4.5 mg L(-1)). Under this optimum condition the removal percentage for MB, AO, EY and BG dyes 97.58, 94.66, 96.22 and 94.93, respectively. The adsorption rate well fitted by pseudo second-order while adsorption capacity according to the Langmuir model as best equilibrium isotherm model for BG, MB, AO and EY was 20.48, 21.26, 22.34 and 21.29 mg g(-1), respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Tolerance to a Hair Dye Product Containing 2-Methoxymethyl-P-Phenylenediamine in an Ethnically Diverse Population of P-Phenylenediamine-Allergic Individuals.

PubMed

Zahir, Amir; Kindred, Chesahna; Blömeke, Brunhilde; Goebel, Carsten; Gaspari, Anthony A

Allergic contact dermatitis after exposure to p-phenylenediamine (PPD)-containing hair dye products is a common and important clinical problem. Because there is a high rate of cross-elicitation of allergic contact dermatitis to other important hair dye products (such as p-toluene diamine and other aminophenol hair dyes) in PPD-allergic patients, safer alternative dyes with excellent hair coloring options are needed. This study aimed to study tolerance to Me-PPD in a PPD-allergic cohort. Twenty ethnically diverse volunteers with a history of contact dermatitis to hair dyes or other PPD-containing chemicals and positive patch test results to 1% PPD in petrolatum were recruited to study their immediate and delayed skin reactivity to PPD, vehicle control, and 2-methoxy-methyl-PPD (Me-PPD) using the allergy alert test (simulating hair dyeing conditions) on volar forearm skin. This test is a short-contact open patch test. The Me-PPD may offer a safer alternative for PPD-allergic patients with an absent or reduced elicitation response in the allergy alert test simulating hair dye use conditions. The absent or reduced response to Me-PPD diagnosed using the allergy alert test has been shown to help reduce the possibility of moderate to severe cross-elicitation reactions among consumers during hair dyeing.

Comparison of thermal, salt and dye tracing to estimate shallow flow velocities: Novel triple-tracer approach

NASA Astrophysics Data System (ADS)

Abrantes, João R. C. B.; Moruzzi, Rodrigo B.; Silveira, Alexandre; de Lima, João L. M. P.

2018-02-01

The accurate measurement of shallow flow velocities is crucial to understand and model the dynamics of sediment and pollutant transport by overland flow. In this study, a novel triple-tracer approach was used to re-evaluate and compare the traditional and well established dye and salt tracer techniques with the more recent thermal tracer technique in estimating shallow flow velocities. For this purpose a triple tracer (i.e. dyed-salted-heated water) was used. Optical and infrared video cameras and an electrical conductivity sensor were used to detect the tracers in the flow. Leading edge and centroid velocities of the tracers were measured and the correction factors used to determine the actual mean flow velocities from tracer measured velocities were compared and investigated. Experiments were carried out for different flow discharges (32-1813 ml s-1) on smooth acrylic, sand, stones and synthetic grass bed surfaces with 0.8, 4.4 and 13.2% slopes. The results showed that thermal tracers can be used to estimate shallow flow velocities, since the three techniques yielded very similar results without significant differences between them. The main advantages of the thermal tracer were that the movement of the tracer along the measuring section was more easily visible than it was in the real image videos and that it was possible to measure space-averaged flow velocities instead of only one velocity value, with the salt tracer. The correction factors used to determine the actual mean velocity of overland flow varied directly with Reynolds and Froude numbers, flow velocity and slope and inversely with flow depth and bed roughness. In shallow flows, velocity estimation using tracers entails considerable uncertainty and caution must be taken with these measurements, especially in field studies where these variables vary appreciably in space and time.

Vascular functioning and the water balance of ripening kiwifruit (Actinidia chinensis) berries

PubMed Central

Clearwater, Michael J.; Luo, Zhiwei; Ong, Sam Eng Chye; Blattmann, Peter; Thorp, T. Grant

2012-01-01

Indirect evidence suggests that water supply to fleshy fruits during the final stages of development occurs through the phloem, with the xylem providing little water, or acting as a pathway for water loss back to the plant. This inference was tested by examining the water balance and vascular functioning of ripening kiwifruit berries (Actinidia chinensis var. chinensis ‘Hort16A’) exhibiting a pre-harvest ‘shrivel’ disorder in California, and normal development in New Zealand. Dye labelling and mass balance experiments indicated that the xylem and phloem were both functional and contributed approximately equally to the fruit water supply during this stage of development. The modelled fruit water balance was dominated by transpiration, with net water loss under high vapour pressure deficit (Da) conditions in California, but a net gain under cooler New Zealand conditions. Direct measurement of pedicel sap flow under controlled conditions confirmed inward flows in both the phloem and xylem under conditions of both low and high Da. Phloem flows were required for growth, with gradual recovery after a step increase in Da. Xylem flows alone were unable to support growth, but did supply transpiration and were responsive to Da-induced pressure fluctuations. The results suggest that the shrivel disorder was a consequence of a high fruit transpiration rate, and that the perception of complete loss or reversal of inward xylem flows in ripening fruits should be re-examined. PMID:22155631

Design and characterization of poly(dimethylsiloxane)-based valves for interfacing continuous-flow sampling to microchip electrophoresis.

PubMed

Li, Michelle W; Huynh, Bryan H; Hulvey, Matthew K; Lunte, Susan M; Martin, R Scott

2006-02-15

This work describes the fabrication and evaluation of a poly(dimethyl)siloxane (PDMS)-based device that enables the discrete injection of a sample plug from a continuous-flow stream into a microchannel for subsequent analysis by electrophoresis. Devices were fabricated by aligning valving and flow channel layers followed by plasma sealing the combined layers onto a glass plate that contained fittings for the introduction of liquid sample and nitrogen gas. The design incorporates a reduced-volume pneumatic valve that actuates (on the order of hundreds of milliseconds) to allow analyte from a continuously flowing sampling channel to be injected into a separation channel for electrophoresis. The injector design was optimized to include a pushback channel to flush away stagnant sample associated with the injector dead volume. The effect of the valve actuation time, the pushback voltage, and the sampling stream flow rate on the performance of the device was characterized. Using the optimized design and an injection frequency of 0.64 Hz showed that the injection process is reproducible (RSD of 1.77%, n = 15). Concentration change experiments using fluorescein as the analyte showed that the device could achieve a lag time as small as 14 s. Finally, to demonstrate the potential uses of this device, the microchip was coupled to a microdialysis probe to monitor a concentration change and sample a fluorescein dye mixture.

Hydraulic Modeling of Lock Approaches

DTIC Science & Technology

2016-08-01

transport of conservative constituents, such as dye clouds, as well as sediment transport that is coupled to bed and hydrodynamic changes. This code is...being developed at ERDC’s CHL and has been used for a wide variety of applications including flow and sediment transport in complex sections of the...Mississippi River, tidal conditions in southern California, and flow field changes caused by vessel traffic in the Houston Ship Channel . For this

Temperature measurement in a compressible flow field using laser-induced iodine fluorescence

NASA Technical Reports Server (NTRS)

Fletcher, D. G.; Mcdaniel, J. C.

1987-01-01

The thermometric capability of a two-line fluorescence technique using iodine seed molecules in air is investigated analytically and verified experimentally in a known steady compressible flow field. Temperatures ranging from 165 to 295 K were measured in the flowfield using two iodine transitions accessed with a 30-GHz dye-laser scan near 543 nm. The effect of pressure broadening on temperature measurement is evaluated.

The Effect of Break Edge Configuration on the Aerodynamics of Anti-Ice Jet Flow

NASA Astrophysics Data System (ADS)

Tatar, V.; Yildizay, H.; Aras, H.

2015-05-01

One of the components of a turboprop gas turbine engine is the Front Bearing Structure (FBS) which leads air into the compressor. FBS directly encounters with ambient air, as a consequence ice accretion may occur on its static vanes. There are several aerodynamic parameters which should be considered in the design of anti-icing system of FBS, such as diameter, position, exit angle of discharge holes, etc. This research focuses on the effects of break edge configuration over anti-ice jet flow. Break edge operation is a process which is applied to the hole in order to avoid sharp edges which cause high stress concentration. Numerical analyses and flow visualization test have been conducted. Four different break edge configurations were used for this investigation; without break edge, 0.35xD, 74xD, 0.87xD. Three mainstream flow conditions at the inlet of the channel are defined; 10m/s, 20 m/s and 40 m/s. Shear stresses are extracted from numerical analyses near the trailing edge of pressure surface where ice may occur under icing conditions. A specific flow visualization method was used for the experimental study. Vane surface near the trailing edge was dyed and thinner was injected into anti-ice jet flow in order to remove dye from the vane surface. Hence, film effect on the surface could be computed for each testing condition. Thickness of the dye removal area of each case was examined. The results show noticeable effects of break edge operation on jet flow, and the air film effectiveness decreases when mainstream inlet velocity decreases.

Structurally integrated organic light emitting device-based sensors for gas phase and dissolved oxygen.

PubMed

Shinar, Ruth; Zhou, Zhaoqun; Choudhury, Bhaskar; Shinar, Joseph

2006-05-24

A compact photoluminescence (PL)-based O2 sensor utilizing an organic light emitting device (OLED) as the light source is described. The sensor device is structurally integrated. That is, the sensing element and the light source, both typically thin films that are fabricated on separate glass substrates, are attached back-to-back. The sensing elements are based on the oxygen-sensitive dyes Pt- or Pd-octaethylporphyrin (PtOEP or PdOEP, respectively), which are embedded in a polystyrene (PS) matrix, or dissolved in solution. Their performance is compared to that of a sensing element based on tris(4,7-diphenyl-l,10-phenanthroline) Ru II (Ru(dpp)) embedded in a sol-gel film. A green OLED light source, based on tris(8-hydroxy quinoline Al (Alq3), was used to excite the porphyrin dyes; a blue OLED, based on 4,4'-bis(2,2'-diphenylviny1)-1,1'-biphenyl, was used to excite the Ru(dpp)-based sensing element. The O2 level was monitored in the gas phase and in water, ethanol, and toluene solutions by measuring changes in the PL lifetime tau of the O2-sensitive dyes. The sensor performance was evaluated in terms of the detection sensitivity, dynamic range, gas flow rate, and temperature effect, including the temperature dependence of tau in pure Ar and O2 atmospheres. The dependence of the sensitivity on the preparation procedure of the sensing film and on the PS and dye concentrations in the sensing element, whether a solid matrix or solution, were also evaluated. Typical values of the detection sensitivity in the gas phase, S(g) identical with tau(0% O2)/tau(100% O2), at 23 degrees C, were approximately 35 to approximately 50 for the [Alq3 OLED[/[PtOEP dye] pair; S(g) exceeded 200 for the Alq3/PdOEP sensor. For dissolved oxygen (DO) in water and ethanol, S(DO) (defined as the ratio of tau in de-oxygenated and oxygen-saturated solutions) was approximately 9.5 and approximately 11, respectively, using the PtOEP-based film sensor. The oxygen level in toluene was measured with PtOEP dissolved directly in the solution. That sensor exhibited a high sensitivity, but a limited dynamic range. Effects of aggregation of dye molecules, sensing film porosity, and the use of the OLED-based sensor arrays for O2 and multianalyte detection are also discussed.

Nanorod-Based Fast-Response Pressure-Sensitive Paints

NASA Technical Reports Server (NTRS)

Bencic, Timothy; VanderWal, Randall

2007-01-01

A proposed program of research and development would be devoted to exploitation of nanomaterials in pressuresensitive paints (PSPs), which are used on wind-tunnel models for mapping surface pressures associated with flow fields. Heretofore, some success has been achieved in measuring steady-state pressures by use of PSPs, but success in measuring temporally varying pressures has been elusive because of the inherent slowness of the optical responses of these materials. A PSP contains a dye that luminesces in a suitable wavelength range in response to photoexcitation in a shorter wavelength range. The luminescence is quenched by oxygen at a rate proportional to the partial pressure of oxygen and thus proportional to the pressure of air. As a result, the intensity of luminescence varies inversely with the pressure of air. The major problem in developing a PSP that could be easily applied to a wind-tunnel model and could be useful for measuring rapidly varying pressure is to provide very high gas diffusivity for rapid, easy transport of oxygen to and from active dye molecules. Most PSPs include polymer-base binders, which limit the penetration of oxygen to dye molecules, thereby reducing responses to pressure fluctuations. The proposed incorporation of nanomaterials (somewhat more specifically, nanorods) would result in paints having nanostructured surfaces that, relative to conventional PSP surfaces, would afford easier and more nearly complete access of oxygen molecules to dye molecules. One measure of greater access is effective surface area: For a typical PSP as proposed applied to a given solid surface, the nanometer-scale structural features would result in an exposed surface area more than 100 times that of a conventional PSP, and the mass of proposed PSP needed to cover the surface would be less than tenth of the mass of the conventional PSP. One aspect of the proposed development would be to synthesize nanorods of Si/SiO2, in both tangle-mat and regular- array forms, by use of chemical vapor deposition (CVD) and wet chemical processes, respectively. The rods would be coated with a PSP dye, and the resulting PSP signals would be compared with those obtained from PSP dye coats on conventional support materials. Another aspect of the proposed development would be to seek to exploit the quantum properties of nanorods of a suitable semiconductor (possibly GaN), which would be synthesized by CVD. These quantum properties of semiconductor nanorods include narrow-wavelength-band optical absorption and emission characteristics that vary with temperature. The temperature sensitivity might enable simultaneous measurement of fluctuating temperature and pressure and to provide a temperature correction for the PSP response.

Effect of indigo dye effluent on the growth, biomass production and phenotypic plasticity of Scenedesmus quadricauda (Chlorococcales).

PubMed

Chia, Mathias A; Musa, Rilwan I

2014-03-01

The effect of indigo dye effluent on the freshwater microalga Scenedesmus quadricauda ABU12 was investigated under controlled laboratory conditions. The microalga was exposed to different concentrations of the effluent obtained by diluting the dye effluent from 100 to 175 times in bold basal medium (BBM). The growth rate of the microalga decreased as indigo dye effluent concentration increased (p <0.05). The EC50 was found to be 166 dilution factor of the effluent. Chlorophyll a, cell density and dry weight production as biomarkers were negatively affected by high indigo dye effluent concentration, their levels were higher at low effluent concentrations (p <0.05). Changes in coenobia size significantly correlated with the dye effluent concentration. A shift from large to small coenobia with increasing indigo dye effluent concentration was obtained. We conclude that even at low concentrations; effluents from textile industrial processes that use indigo dye are capable of significantly reducing the growth and biomass production, in addition to altering the morphological characteristics of the freshwater microalga S. quadricauda. The systematic reduction in the number of cells per coenobium observed in this study further confirms that environmental stress affects coenobium structure in the genus Scenedesmus, which means it can be considered an important biomarker for toxicity testing.

Experimental parametric study of jet vortex generators for flow separation control

NASA Technical Reports Server (NTRS)

Selby, Gregory

1991-01-01

A parametric wind-tunnel study was performed with jet vortex generators to determine their effectiveness in controlling flow separation associated with low-speed turbulence flow over a two-dimensional rearward-facing ramp. Results indicate that flow-separation control can be accomplished, with the level of control achieved being a function of jet speed, jet orientation (with respect to the free-stream direction), and orifice pattern (double row of jets vs. single row). Compared to slot blowing, jet vortex generators can provide an equivalent level of flow control over a larger spanwise region (for constant jet flow area and speed). Dye flow visualization tests in a water tunnel indicated that the most effective jet vortex generator configurations produced streamwise co-rotating vortices.

Sentinel lymph node mapping in endometrial cancer: comparison of fluorescence dye with traditional radiocolloid and blue.

PubMed

Papadia, Andrea; Gasparri, Maria Luisa; Buda, Alessandro; Mueller, Michael D

2017-10-01

Sentinel lymph node (SLN) mapping in endometrial cancer (EMCA) is rapidly gaining acceptance in the clinical community. As compared to a full lymphadenectomy in every patient, to a selective lymphadenectomy after frozen section of uterus in selected patients with intrauterine risk factors or to a strategy in which a lymphadenectomy is always omitted, SLN mapping seems to be a reasonable and oncologically safe middle ground. Various protocols can be used when applying an SLN mapping. In this manuscript we review the characteristics, toxicity and clinical impact of technetium-99m radiocolloid (Tc-99m), of the blue dyes (methylene blue, isosulfan blue and patent blue) and of indocyanine green (ICG). ICG has an excellent toxicity profile, has higher overall and bilateral detection rates as compared to blue dyes and higher bilateral detection rates as compared to a combination of Tc-99m and blue dye. The detrimental effect of BMI on the detection rates is attenuated when ICG is used as a tracer. The ease of use of the ICG SLN mapping is perceived by the patients as a better quality of care delivered. Whenever possible, ICG should be favored over the other tracers for SLN mapping in EMCA patients.

Pore-scale supercritical CO2 dissolution and mass transfer under imbibition conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Chun; Zhou, Quanlin; Kneafsey, Timothy J.

2016-06-01

In modeling of geological carbon storage, dissolution of supercritical CO2 (scCO2) is often assumed to be instantaneous with equilibrium phase partitioning. In contrast, recent core-scale imbibition experiments have shown a prolonged depletion of residual scCO2 by dissolution, implying a non-equilibrium mechanism. In this study, eight pore-scale scCO2 dissolution experiments in a 2D heterogeneous, sandstone-analogue micromodel were conducted at supercritical conditions (9 MPa and 40 °C). The micromodel was first saturated with deionized (DI) water and drained by injecting scCO2 to establish a stable scCO2 saturation. DI water was then injected at constant flow rates after scCO2 drainage was completed. Highmore » resolution time-lapse images of scCO2 and water distributions were obtained during imbibition and dissolution, aided by a scCO2-soluble fluorescent dye introduced with scCO2 during drainage. These images were used to estimate scCO2 saturations and scCO2 depletion rates. Experimental results show that (1) a time-independent, varying number of water-flow channels are created during imbibition and later dominant dissolution by the random nature of water flow at the micromodel inlet, and (2) a time-dependent number of water-flow channels are created by coupled imbibition and dissolution following completion of dominant imbibition. The number of water-flow paths, constant or transient in nature, greatly affects the overall depletion rate of scCO2 by dissolution. The average mass fraction of dissolved CO2 (dsCO2) in water effluent varies from 0.38% to 2.72% of CO2 solubility, indicating non-equilibrium scCO2 dissolution in the millimeter-scale pore network. In general, the transient depletion rate decreases as trapped, discontinuous scCO2 bubbles and clusters within water-flow paths dissolve, then remains low with dissolution of large bypassed scCO2 clusters at their interfaces with longitudinal water flow, and finally increases with coupled transverse water flow and enhanced dissolution of large scCO2 clusters. The three stages of scCO2 depletion, common to experiments with time-independent water-flow paths, are revealed by zoom-in image analysis of individual scCO2 bubbles and clusters. The measured relative permeability of water, affected by scCO2 dissolution and bi-modal permeability, shows a non-monotonic dependence on saturation. The results for experiments with different injection rates imply that the non-equilibrium nature of scCO2 dissolution becomes less important when water flow is relatively low and the time scale for dissolution is large, and more pronounced when heterogeneity is strong.« less

Research on dispose of wastewater from printing and dyeing by CWF combined with Iron-carbon Microelectrolysis

NASA Astrophysics Data System (ADS)

Chen, Xin; Ye, Tingjin; Xu, Zizhen; Chen, Xiaogang; Shi, Liang; He, Lingfeng; Zhang, Yongli

2018-03-01

The carboxymethylchitosan cladding coal ash (CWF) was oxidized by the high temperature using coal ash and sodium carboxymethyl chitosan as raw and processed material for treatment of simulated and actual printing and dyeing wastewater over iron-carbon micro-electrolysis. The results on pH and CWF dosage for effluent dispose were evaluated by the decolorization rate, COD removal efficiency and turbidity removal rate. The experimental results indicated that the decolorization rate was first augmented and then declined with the increase of pH, and attained a peak value when pH was at 5-6. The COD removal efficiency augmented with the augmented of pH, and attained a peak value when pH was 6-7. The turbidity removal rate was first increases and afterwards decreases with the augment of pH, and attained a peak value when pH was at 5-6. Furthermore, the optimum pH for the treatment of simulated dyeing wastewater was 6 over iron-carbon micro-electrolysis, which indicated that the appropriate pH can promote the degradation of wastewater.

Traveltime and reaeration characteristics for a reach of the Rio Grande, Albuquerque, New Mexico, October 1991

USGS Publications Warehouse

Waltemeyer, S.D.

1994-01-01

Traveltime characteristics were determined using stream-velocity data and tracer-dye data for a reach of the Rio Grande. Traveltimes determined by the stream-velocity method were virtually the same as those determined by the tracer-dye and tracer-gas technique. The mean velocity of the stream was 1.12 miles per hour at a flow of about 300 cubic feet per second. Reaeration characteristics were determined using a propane tracer gas and a tracer-dye (rhodamine WT). Reaeration coefficients were adjusted for water temperature and the effects of wind movement on the water surface. The peak method-adjusted reaeration-coefficient mean value for the reach was 7.0 per day and ranged from 4.6 to 8.3 per day. The area method-adjusted reaeration- coefficient mean value for the reach was 7.7 per day and ranged from 5.5 to 10.4 per day.

Outfall siting with dye-buoy remote sensing of coastal circulation

NASA Technical Reports Server (NTRS)

Munday, J. C., Jr.; Welch, C. S.; Gordon, H. H.

1978-01-01

A dye-buoy remote sensing technique has been applied to estuarine siting problems that involve fine-scale circulation. Small hard cakes of sodium fluorescein and polyvinyl alcohol, in anchored buoys and low-windage current followers, dissolve to produce dye marks resolvable in 1:60,000 scale color and color infrared imagery. Lagrangian current vectors are determined from sequential photo coverage. Careful buoy placement reveals surface currents and submergence near fronts and convergence zones. The technique has been used in siting two sewage outfalls in Hampton Roads, Virginia: In case one, the outfall region during flood tide gathered floating materials in a convergence zone, which then acted as a secondary source during ebb; for better dispersion during ebb, the proposed outfall site was moved further offshore. In case two, flow during late flood was found to divide, with one half passing over shellfish beds; the proposed outfall site was consequently moved to keep effluent in the other half.

On a PLIF quantification methodology in a nonlinear dye response regime

NASA Astrophysics Data System (ADS)

Baj, P.; Bruce, P. J. K.; Buxton, O. R. H.

2016-06-01

A new technique of planar laser-induced fluorescence calibration is presented in this work. It accounts for a nonlinear dye response at high concentrations, an illumination light attenuation and a secondary fluorescence's influence in particular. An analytical approximation of a generic solution of the Beer-Lambert law is provided and utilized for effective concentration evaluation. These features make the technique particularly well suited for high concentration measurements, or those with a large range of concentration values, c, present (i.e. a high dynamic range of c). The method is applied to data gathered in a water flume experiment where a stream of a fluorescent dye (rhodamine 6G) was released into a grid-generated turbulent flow. Based on these results, it is shown that the illumination attenuation and the secondary fluorescence introduce a significant error into the data quantification (up to 15 and 80 %, respectively, for the case considered in this work) unless properly accounted for.

Evaluation of optimal DNA staining for triggering by scanning fluorescence microscopy (SFM)

NASA Astrophysics Data System (ADS)

Mittag, Anja; Marecka, Monika; Pierzchalski, Arkadiusz; Malkusch, Wolf; Bocsi, József; Tárnok, Attila

2009-02-01

In imaging and flow cytometry, DNA staining is a common trigger signal for cell identification. Selection of the proper DNA dye is restricted by the hardware configuration of the instrument. The Zeiss Imaging Solutions GmbH (München, Germany) introduced a new automated scanning fluorescence microscope - SFM (Axio Imager.Z1) which combines fluorescence imaging with cytometric parameters measurement. The aim of the study was to select optimal DNA dyes as trigger signal in leukocyte detection and subsequent cytometric analysis of double-labeled leukocytes by SFM. Seven DNA dyes (DAPI, Hoechst 33258, Hoechst 33342, POPO-3, PI, 7-AAD, and TOPRO-3) were tested and found to be suitable for the implemented filtersets (fs) of the SFM (fs: 49, fs: 44, fs: 20). EDTA blood was stained after erythrocyte lysis with DNA dye. Cells were transferred on microscopic slides and embedded in fluorescent mounting medium. Quality of DNA fluorescence signal as well as spillover signals were analyzed by SFM. CD45-APC and CD3-PE as well as CD4-FITC and CD8-APC were selected for immunophenotyping and used in combination with Hoechst. Within the tested DNA dyes DAPI showed relatively low spillover and the best CV value. Due to the low spillover of UV DNA dyes a triple staining of Hoechst and APC and PE (or APC and FITC, respectively) could be analyzed without difficulty. These results were confirmed by FCM measurements. DNA fluorescence is applicable for identifying and triggering leukocytes in SFM analyses. Although some DNA dyes exhibit strong spillover in other fluorescence channels, it was possible to immunophenotype leukocytes. DAPI seems to be best suitable for use in the SFM system and will be used in protocol setups as primary parameter.

Influence of dielectric barrier discharge treatment on mechanical and dyeing properties of wool

NASA Astrophysics Data System (ADS)

Rahul, NAVIK; Sameera, SHAFI; Md Miskatul, ALAM; Md Amjad, FAROOQ; Lina, LIN; Yingjie, CAI

2018-06-01

Physical and chemical properties of wool surface significantly affect the absorbency, rate of dye bath exhaustion and fixation of the industrial dyes. Hence, surface modification is a necessary operation prior to coloration process in wool wet processing industries. Plasma treatment is an effective alternative for physiochemical modification of wool surface. However, optimum processing parameters to get the expected modification are still under investigation, hence this technology is still under development in the wool wet processing industries. Therefore, in this paper, treatment parameters with the help of simple dielectric barrier discharge plasma reactor and air as a plasma gas, which could be a promising combination for treatment of wool substrate at industrial scale were schematically studied, and their influence on the water absorbency, mechanical, and dyeing properties of twill woven wool fabric samples are reported. It is expected that the results will assist to the wool coloration industries to improve the dyeing processes.

Flow Charts: Visualization of Vector Fields on Arbitrary Surfaces

PubMed Central

Li, Guo-Shi; Tricoche, Xavier; Weiskopf, Daniel; Hansen, Charles

2009-01-01

We introduce a novel flow visualization method called Flow Charts, which uses a texture atlas approach for the visualization of flows defined over curved surfaces. In this scheme, the surface and its associated flow are segmented into overlapping patches, which are then parameterized and packed in the texture domain. This scheme allows accurate particle advection across multiple charts in the texture domain, providing a flexible framework that supports various flow visualization techniques. The use of surface parameterization enables flow visualization techniques requiring the global view of the surface over long time spans, such as Unsteady Flow LIC (UFLIC), particle-based Unsteady Flow Advection Convolution (UFAC), or dye advection. It also prevents visual artifacts normally associated with view-dependent methods. Represented as textures, Flow Charts can be naturally integrated into hardware accelerated flow visualization techniques for interactive performance. PMID:18599918

Microfluidic on-chip fluorescence-activated interface control system

PubMed Central

Haiwang, Li; Nguyen, N. T.; Wong, T. N.; Ng, S. L.

2010-01-01

A microfluidic dynamic fluorescence-activated interface control system was developed for lab-on-a-chip applications. The system consists of a straight rectangular microchannel, a fluorescence excitation source, a detection sensor, a signal conversion circuit, and a high-voltage feedback system. Aqueous NaCl as conducting fluid and aqueous glycerol as nonconducting fluid were introduced to flow side by side into the straight rectangular microchannel. Fluorescent dye was added to the aqueous NaCl to work as a signal representing the interface position. Automatic control of the liquid interface was achieved by controlling the electroosmotic effect that exists only in the conducting fluid using a high-voltage feedback system. A LABVIEW program was developed to control the output of high-voltage power supply according the actual interface position, and then the interface position is modified as the output of high-voltage power supply. At last, the interface can be moved to the desired position automatically using this feedback system. The results show that the system presented in this paper can control an arbitrary interface location in real time. The effects of viscosity ratio, flow rates, and polarity of electric field were discussed. This technique can be extended to switch the sample flow and droplets automatically. PMID:21173886

Conformation and stretching of end-tethered polymers in pressure-driven flow under confinement

NASA Astrophysics Data System (ADS)

Roy, Tamal; Hardt, Steffen; InstituteNano-; Microfludics, Technische Universität Darmstadt Team

2016-11-01

Understanding of the conformation and dynamics of polymers under confinement is important for both fundamental studies and applications. We experimentally study the conformation and stretching of surface-tethered polymer chains confined between parallel surfaces and exposed to a pressure-driven flow. λ-DNA molecules are tethered to the wall of a microchannel of height smaller than the contour lengths of the molecules. The DNA molecules, stained with a fluorescent dye, are visualized by epifluorescence and laser-scanning confocal microscopy (LSCM). The effects of the channel height, flow rate and contour length on the extension of the molecules are determined from epifluorescence images. From LSCM images the complete conformation and orientation of the DNA molecules is inferred. We find that the fractional extension of the molecules is uniquely determined by the fluid shear stress at the tethering surface and the chain contour length. There is no explicit influence of the channel height in the range of contour lengths we consider. We also derive analytical scaling relationships (in the weak and strong extension limits) that explain the experimentally observed stretching characteristics. This work is supported by Deutsche Forschungsgemeinschaft (Grant No. HA 2696/33-1).

Geographical Distribution of MDR1 Expression in Leishmania Isolates, from Greece and Cyprus, Measured by the Rhodamine-123 Efflux Potential of the Isolates, Using Flow Cytometry

PubMed Central

Tsirigotakis, Nikolaos; Christodoulou, Vasiliki; Ntais, Pantelis; Mazeris, Apostolos; Koutala, Eleni; Messaritakis, Ippokratis; Antoniou, Maria

2016-01-01

Leishmaniasis, a neglected vector-borne disease caused by the protozoan parasite Leishmania, is encountered in 98 countries causing serious concerns to public health. The most alarming is the development of parasite drug resistance, a phenomenon increasingly encountered in the field rendering chemotherapy ineffective. Although resistance to drugs is a complex phenomenon, the rate of efflux of the fluorescent dye Rhodamine-123 from the parasite body, using flow cytometry, is an indication of the isolate's ability to efflux the drug, thus avoiding death. The rate of efflux measured 275 Leishmania strains, isolated from patients and dogs from Greece and Cyprus, was measured and mapped to study the geographical distribution of the multidrug resistance (MDR) gene expression as an indication of the drug resistance of the parasite. The map showed that out of the seven prefectures, where dogs presented high efflux rates, five also had patients with high efflux rates. In one, out of the 59 prefectures studied, the highest number of isolates with efflux slope α > 1, in both human and dog isolates, was found; a fact which may suggest that spread of drug resistance is taking place. The virulence of the Leishmania strains, assessed after infecting human macrophages of the THP-1 cell line, fluctuated from 1% to 59.3% with only 2.5% of the isolates showing infectivity > 50%. The most virulent strains were isolated from Attica and Crete. PMID:27001764

Silk fabric dyed with extract of sophora flower bud.

PubMed

Yan, Su; Pan, Shanshan; Ji, Junling

2018-02-01

This study analysed the use of sophora flower bud extract for dyeing and the resulting colour character and fastness of dyed silk fabric. The pigment composition on the silk fabric and recycling of this extract were also studied. The results indicated that the dyed silk fabric possessed good washing, rubbing and perspiration fastness, and the pigment composition on the silk fabric was mainly rutin and quercetin. The average recovery rate of the dye was 55.00%. These results demonstrate that the sophora flower bud extract is an effective natural dye.

40 CFR 63.4292 - What operating limits must I meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Other Textiles Emission Limitations § 63.4292 What operating limits must I meet? (a) For any web coating... material option; web coating/printing operation or dyeing/finishing operation on which you use the emission... controlled web coating/printing operation or dyeing/finishing operation on which you use the emission rate...

40 CFR 63.4292 - What operating limits must I meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Other Textiles Emission Limitations § 63.4292 What operating limits must I meet? (a) For any web coating... material option; web coating/printing operation or dyeing/finishing operation on which you use the emission... controlled web coating/printing operation or dyeing/finishing operation on which you use the emission rate...

40 CFR 63.4292 - What operating limits must I meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Other Textiles Emission Limitations § 63.4292 What operating limits must I meet? (a) For any web coating... material option; web coating/printing operation or dyeing/finishing operation on which you use the emission... controlled web coating/printing operation or dyeing/finishing operation on which you use the emission rate...

Equilibrium and kinetic adsorption study of a cationic dye by a natural adsorbent--silkworm pupa.

PubMed

Noroozi, B; Sorial, G A; Bahrami, H; Arami, M

2007-01-02

In this work the use of silkworm pupa, which is the waste of silk spinning industries has been investigated as an adsorbent for the removal of C.I. Basic Blue 41. The amino acid nature of the pupa provided a reasonable capability for dye removal. Equilibrium adsorption isotherms and kinetics were investigated. The adsorption equilibrium data were analyzed by using various adsorption isotherm models and the results have shown that adsorption behavior of the dye could be described reasonably well by either Langmuir or Freundlich models. The characteristic parameters for each isotherm have been determined. The monolayer adsorption capacity was determined to be 555 mg/g. Kinetic studies indicated that the adsorption follows pseudo-second-order kinetics with a rate constant of 0.0434 and 0.0572 g/min mg for initial dye concentration of 200 mg/l at 20 and 40 degrees C, respectively. Kinetic studies showed that film diffusion and intra-particle diffusion were simultaneously operating during the adsorption process. The rate constant for intra-particle diffusion was estimated to be 1.985 mg/g min(0.5).

Decolorization and biogas production by an anaerobic consortium: effect of different azo dyes and quinoid redox mediators.

PubMed

Alvarez, L H; Valdez-Espinoza, R; García-Reyes, R B; Olivo-Alanis, D; Garza-González, M T; Meza-Escalante, E R; Gortáres-Moroyoqui, P

2015-01-01

The inhibitory effect of azo dyes and quinoid compounds on an anaerobic consortium was evaluated during a decolorization process and biogas production. In addition, the impact of quinoid compounds such as lawsone (LAW) and anthraquinone-2,6-disulfonate (AQDS) on the rate of decolorization of Direct Blue 71 (DB71) was assessed. The anaerobic consortium was not completely inhibited under all tested dye concentrations (0.1-2 mmol l(-1)), evidenced by an active decolorization process and biogas production. The presence of quinoid compounds at different concentrations (4, 8, and 12 mmol l(-1)) also inhibited biogas production compared to the control incubated without the quinoid compounds. In summary, the anaerobic consortium was affected to a greater extent by increasing the quantity of azo dyes or quinoid compounds. Nevertheless, at a lower concentration (1 mmol l(-1)) of quinoid compounds, the anaerobic consortium effectively decolorized 2 mmol l(-1) of DB71, increasing up to 5.2- and 20.4-fold the rate of decolorization with AQDS and LAW, respectively, compared to the control lacking quinoid compounds.

Flow chemistry meets advanced functional materials.

PubMed

Myers, Rebecca M; Fitzpatrick, Daniel E; Turner, Richard M; Ley, Steven V

2014-09-22

Flow chemistry and continuous processing techniques are beginning to have a profound impact on the production of functional materials ranging from quantum dots, nanoparticles and metal organic frameworks to polymers and dyes. These techniques provide robust procedures which not only enable accurate control of the product material's properties but they are also ideally suited to conducting experiments on scale. The modular nature of flow and continuous processing equipment rapidly facilitates reaction optimisation and variation in function of the products. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Exploring Flow Procedures for Diazonium Formation.

PubMed

Hu, Te; Baxendale, Ian R; Baumann, Marcus

2016-07-14

The synthesis of diazonium salts is historically an important transformation extensively utilized in dye manufacture. However the highly reactive nature of the diazonium functionality has additionally led to the development of many new reactions including several carbon-carbon bond forming processes. It is therefore highly desirable to determine optimum conditions for the formation of diazonium compounds utilizing the latest processing tools such as flow chemistry to take advantage of the increased safety and continuous manufacturing capabilities. Herein we report a series of flow-based procedures to prepare diazonium salts for subsequent in-situ consumption.

Uptake of dyes by a promising locally available agricultural solid waste: coir pith.

PubMed

Namasivayam, C; Radhika, R; Suba, S

2001-01-01

The adsorption of rhodamine-B and acid violet by coir pith carbon was carried out by varying the parameters such as agitation time, dye concentration, adsorbent dose and pH. The adsorption followed both Langmuir and Freundlich isotherms. The adsorption capacity was found to be 2.56 mg and 8.06 mg dye per g of the adsorbent for rhodamine-B and acid violet, respectively. Adsorption of dyes followed first order rate kinetics. Acidic pH was favorable for the adsorption of acid violet and alkaline pH was favorable to rhodamine-B. Desorption studies showed that alkaline pH was favorable for the desorption of acid violet and acidic pH was favorable for the desorption of rhodamine-B.

A rapid method for measuring intracellular pH using BCECF-AM.

PubMed

Ozkan, Pinar; Mutharasan, Raj

2002-08-15

A rapid intracellular pH (pH(i)) measurement method based on initial rate of increase of fluorescence ratio of 2',7'-bis(2-carboxyethyl)-5,6-carboxyfluorescein upon dye addition to a cell suspension in growth medium is reported. A dye transport model that describes dye concentration and fluorescence values in intracellular and extracellular spaces provides the mathematical basis for the approach. Experimental results of ammonium chloride challenge response of the two suspension cells, Spodoptera frugiperda and Chinese hamster ovary (CHO) cells, successfully compared with results obtained using traditional perfusion method. Since the cell suspension does not require any preparation, measurement of pH(i) can be completed in about 1 min minimizing any potential errors due to dye leakage.

Power ultrasound-assisted cleaner leather dyeing technique: influence of process parameters.

PubMed

Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

2004-03-01

The application of power ultrasound to leather processing has a significant role in the concept of "clean technology" for leather production. The effect of power ultrasound in leather dyeing has been compared with dyeing in the absence of ultrasound and conventional drumming. The power ultrasound source used in these experiments was ultrasonic cleaner (150 W and 33 kHz). The effect of various process parameters such as amount of dye offer, temperature, and type of dye has been experimentally found out. The effect of presonication of dye solution as well as leather has been studied. Experiments at ultrasonic bath temperature were carried out to find out the combined thermal as well as stirring effects of ultrasound. Dyeing in the presence of ultrasound affords about 37.5 (1.8 times) difference as increase in % dye exhaustion or about 50% decrease in the time required for dyeing compared to dyeing in the absence of ultrasound for 4% acid red dye. About 29 (1.55 times) increase in % dye exhaustion or 30% reduction in time required for dyeing was observed using ultrasound at stationary condition compared with conventional dynamic drumming conditions. The effect of ultrasound at constant temperature conditions with a control experiment has also been studied. The dye exhaustion increases as the temperature increases (30-60 degrees C) and better results are observed at higher temperature due to the use of ultrasound. Presonication of dye solution or crust leather prior to the dyeing process has no significant improvement in dye exhaustion, suggesting ultrasound effect is realized when it is applied during the dyeing process. The results indicate that 1697 and 1416 ppm of dye can be reduced in the spent liquor due to the use of ultrasound for acid red (for 100 min) and acid black (for 3 h) dyes, respectively, thereby reducing the pollution load in the effluent stream. The color yield of the leather as inferred from the reflectance measurement indicates that dye offer can be halved when ultrasound is employed to promote dyeing. Scanning electron microscopy analysis of the cross section of the dyed leather indicates that fiber structure is not affected due to the use of ultrasound under the given process conditions. The present study clearly demonstrates that ultrasound can be used as a tool to improve the rate of exhaustion of dye, reduce pollution load in the spent effluent liquor, and improve the quality of leather produced. The study also offered provision to employ optimum levels of chemicals and increases percentage exhaustion for a given time, thereby limiting the pollution load in the tannery effluent, which is of great social concern.

Femtosecond laser pulse optimization for multiphoton cytometry and control of fluorescence

NASA Astrophysics Data System (ADS)

Tkaczyk, Eric Robert

This body of work encompasses optimization of near infrared femtosecond laser pulses both for enhancement of flow cytometry as well as adaptive pulse shaping to control fluorescence. A two-photon system for in vivo flow cytometry is demonstrated, which allows noninvasive quantification of circulating cell populations in a single live mouse. We monitor fluorescently-labeled red blood cells for more than two weeks, and are also able to noninvasively measure circulation times of two distinct populations of breast cancer cells simultaneously in a single mouse. We build a custom laser excitation source in the form of an extended cavity mode-locked oscillator, which enables superior detection in whole blood or saline of cell lines expressing fluorescent proteins including the green fluorescent protein (GFP), tdTomato and mPlum. A mathematical model explains unique features of the signals. The ability to distinguish different fluorescent species is central to simultaneous measurement of multiple molecular targets in high throughput applications including the multiphoton flow cytometer. We demonstrate that two dyes which are not distinguishable to one-photon measurements can be differentiated and in fact quantified in mixture via phase-shaped two-photon excitation pulses found by a genetic algorithm. We also selectively enhance or suppress two-photon fluorescence of numerous common dyes with tailored pulse shapes. Using a multiplicative (rather than ratiometric) fitness parameter, we are able to control the fluorescence while maintaining a strong signal. With this method, we control the two-photon fluorescence of the blue fluorescent protein (BFP), which is of particular interest in investigations of protein-protein interactions, and has frustrated previous attempts of control. Implementing an acousto-optic interferometer, we use the same experimental setup to measure two-photon excitation cross-sections of dyes and prove that photon-photon interferences are the predominant mechanism of control. This research establishes the basis for molecularly tailored pulse shaping in multiphoton flow cytometry, which will advance our ability to probe the biology of circulating cells during disease progression and response to therapy.

Synthesis and characterization of organic dyes with various electron-accepting substituents for p-type dye-sensitized solar cells.

PubMed

Weidelener, Martin; Powar, Satvasheel; Kast, Hannelore; Yu, Ze; Boix, Pablo P; Li, Chen; Müllen, Klaus; Geiger, Thomas; Kuster, Simon; Nüesch, Frank; Bach, Udo; Mishra, Amaresh; Bäuerle, Peter

2014-11-01

Four new donor-π-acceptor dyes differing in their acceptor group have been synthesized and employed as model systems to study the influence of the acceptor groups on the photophysical properties and in NiO-based p-type dye-sensitized solar cells. UV/Vis absorption spectra showed a broad range of absorption coverage with maxima between 331 and 653 nm. Redox potentials as well as HOMO and LUMO energies of the dyes were determined from cyclic voltammetry measurements and evaluated concerning their potential use as sensitizers in p-type dye-sensitized solar cells (p-DSCs). Quantum-chemical density functional theory calculations gave further insight into the frontier orbital distributions, which are relevant for the electronic processes in p-DSCs. In p-DSCs using an iodide/triiodide-based electrolyte, the polycyclic 9,10-dicyano-acenaphtho[1,2-b]quinoxaline (DCANQ) acceptor-containing dye gave the highest power conversion efficiency of 0.08%, which is comparable to that obtained with the perylenemonoimide (PMI)-containing dye. Interestingly, devices containing the DCANQ-based dye achieve a higher V(OC) of 163 mV compared to 158 mV for the PMI-containing dye. The result was further confirmed by impedance spectroscopic analysis showing higher recombination resistance and thus a lower recombination rate for devices containing the DCANQ dye than for PMI dye-based devices. However, the use of the strong electron-accepting tricyanofurane (TCF) group played a negative role in the device performance, yielding an efficiency of only 0.01% due to a low-lying LUMO energy level, thus resulting in an insufficient driving force for efficient dye regeneration. The results demonstrate that a careful molecular design with a proper choice of the acceptor unit is essential for development of sensitizers for p-DSCs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ultrafast electron and energy transfer in dye-sensitized iron oxide and oxyhydroxide nanoparticles.

PubMed

Gilbert, Benjamin; Katz, Jordan E; Huse, Nils; Zhang, Xiaoyi; Frandsen, Cathrine; Falcone, Roger W; Waychunas, Glenn A

2013-10-28

An emerging area in chemical science is the study of solid-phase redox reactions using ultrafast time-resolved spectroscopy. We have used molecules of the photoactive dye 2',7'-dichlorofluorescein (DCF) anchored to the surface of iron(III) oxide nanoparticles to create iron(II) surface atoms via photo-initiated interfacial electron transfer. This approach enables time-resolved study of the fate and mobility of electrons within the solid phase. However, complete analysis of the ultrafast processes following dye photoexcitation of the sensitized iron(III) oxide nanoparticles has not been reported. We addressed this topic by performing femtosecond transient absorption (TA) measurements of aqueous suspensions of uncoated and DCF-sensitized iron oxide and oxyhydroxide nanoparticles, and an aqueous iron(III)-dye complex. Following light absorption, excited state relaxation times of the dye of 115-310 fs were found for all samples. Comparison between TA dynamics on uncoated and dye-sensitized hematite nanoparticles revealed the dye de-excitation pathway to consist of a competition between electron and energy transfer to the nanoparticles. We analyzed the TA data for hematite nanoparticles using a four-state model of the dye-sensitized system, finding electron and energy transfer to occur on the same ultrafast timescale. The interfacial electron transfer rates for iron oxides are very close to those previously reported for DCF-sensitized titanium dioxide (for which dye-oxide energy transfer is energetically forbidden) even though the acceptor states are different. Comparison of the alignment of the excited states of the dye and the unoccupied states of these oxides showed that the dye injects into acceptor states of different symmetry (Ti t2gvs. Fe eg).

Benchtop Detection of Proteins

NASA Technical Reports Server (NTRS)

Scardelletti, Maximilian C.; Varaljay, Vanessa

2007-01-01

A process, and a benchtop-scale apparatus for implementing the process, have been developed to detect proteins associated with specific microbes in water. The process and apparatus may also be useful for detection of proteins in other, more complex liquids. There may be numerous potential applications, including monitoring lakes and streams for contamination, testing of blood and other bodily fluids in medical laboratories, and testing for microbial contamination of liquids in restaurants and industrial food-processing facilities. A sample can be prepared and analyzed by use of this process and apparatus within minutes, whereas an equivalent analysis performed by use of other processes and equipment can often take hours to days. The process begins with the conjugation of near-infrared-fluorescent dyes to antibodies that are specific to a particular protein. Initially, the research has focused on using near-infrared dyes to detect antigens or associated proteins in solution, which has proven successful vs. microbial cells, and streamlining the technique in use for surface protein detection on microbes would theoretically render similar results. However, it is noted that additional work is needed to transition protein-based techniques to microbial cell detection. Consequently, multiple such dye/antibody pairs could be prepared to enable detection of multiple selected microbial species, using a different dye for each species. When excited by near-infrared light of a suitable wavelength, each dye fluoresces at a unique longer wavelength that differs from those of the other dyes, enabling discrimination among the various species. In initial tests, the dye/antibody pairs are mixed into a solution suspected of containing the selected proteins, causing the binding of the dye/antibody pairs to such suspect proteins that may be present. The solution is then run through a microcentrifuge that includes a membrane that acts as a filter in that it retains the dye/antibody/protein complexes while allowing any remaining unbound dye/antibody pairs to flow away. The retained dye/antibody/protein complexes are transferred to a cuvette, wherein they are irradiated with light from a miniature near-infrared laser delivered via a fiber-optic cable. The resulting fluorescence from the dye(s) is measured by use of a miniature spectrometer, the output of which is digitized, then analyzed by laptop computer. The software running in the computer identifies the protein species by the wavelengths of their spectral peaks and determines the amounts of the proteins, and thus, one day, microbes of the various species from the intensities of the peaks. The abovementioned removal of the unbound dye/antibody pairs during centrifugation prevents false positive readings. The process proves successful in detecting proteins in solution and thus can now be employed for use in microbe detection.

Development and validation of ultra-high performance supercritical fluid chromatography method for determination of illegal dyes and comparison to ultra-high performance liquid chromatography method.

PubMed

Khalikova, Maria A; Šatínský, Dalibor; Solich, Petr; Nováková, Lucie

2015-05-18

A novel simple, fast and efficient ultra-high performance supercritical fluid chromatography (UHPSFC) method was developed and validated for the separation and quantitative determination of eleven illegal dyes in chili-containing spices. The method involved a simple ultrasound-assisted liquid extraction of illegal compounds with tetrahydrofuran. The separation was performed using a supercritical fluid chromatography system and CSH Fluoro-Phenyl stationary phase at 70°C. The mobile phase was carbon dioxide and the mixture of methanol:acetonitrile (1:1, v/v) with 2.5% formic acid as an additive at the flow rate 2.0 mL min(-1). The UV-vis detection was accomplished at 500 nm for seven compounds and at 420 nm for Sudan Orange G, Butter Yellow, Fast Garnet GBC and Methyl Red due to their maximum of absorbance. All eleven compounds were separated in less than 5 min. The method was successfully validated and applied using three commercial samples of chili-containing spices - Chili sauce (Indonesia), Feferony sauce (Slovakia) and Mojo sauce (Spain). The linearity range of proposed method was 0.50-9.09 mg kg(-1) (r ≥ 0.995). The detection limits were determined as signal to noise ratio of 3 and were ranged from 0.15 mg kg(-1) to 0.60 mg kg(-1) (1.80 mg kg(-1) for Fast Garnet) for standard solution and from 0.25 mg kg(-1) to 1.00 mg kg(-1) (2.50 mg kg(-1) for Fast Garnet, 1.50 mg kg(-1) for Sudan Red 7B) for chili-containing samples. The recovery values were in the range of 73.5-107.2% and relative standard deviation ranging from 0.1% to 8.2% for within-day precision and from 0.5% to 8.8% for between-day precision. The method showed potential for being used to monitor forbidden dyes in food constituents. The developed UHPSFC method was compared to the UHPLC-UV method. The orthogonality of Sudan dyes separation by these two methods was demonstrated. Benefits and drawbacks were discussed showing the reliability of both methods for monitoring of studied illegal dyes in real food constituents. Copyright © 2015 Elsevier B.V. All rights reserved.

Laser Measurements of the H Atom + Ozone Rate Constant at Atmospheric Temperatures

NASA Astrophysics Data System (ADS)

Liu, Y.; Smith, G. P.; Peng, J.; Reppert, K. J.; Callahan, S. L.

2015-12-01

The exothermic H + O3 reaction produces OH(v) Meinel band emissions, used to derive mesospheric H concentrations and chemical heating rates. We have remeasured its rate constant to reduce resulting uncertainties and the measurement extend to lower mesospheric temperatures using modern laser techniques. H atoms are produced by pulsed ultraviolet laser trace photolysis of O3, followed by reaction of O(D) with added H2. A second, delayed, frequency-mixed dye laser measures the reaction decay rate with the remaining ozone by laser induced fluorescence. We monitor either the H atom decay by 2 photon excitation at 205 nm and detection of red fluorescence, or the OH(v=9) product time evolution with excitation of the B-X (0,9) band at 237 nm and emission in blue B-A bands. By cooling the enclosed low pressure flow cell we obtained measurements from 146-305 K. Small kinetic modeling corrections are made for secondary regeneration of H atoms. The results fully confirm the current NASA JPL recommendation for this rate constant, and establish its extrapolation down to the lower temperatures of the mesosphere. This work was supported by the NSF Aeronomy Program and an NSF Physics summer REU student grant.

Flow Structure and Surface Topology on a UCAV Planform

NASA Astrophysics Data System (ADS)

Elkhoury, Michel; Yavuz, Metin; Rockwell, Donald

2003-11-01

Flow past a X-45 UCAV planform involves the complex generation and interaction of vortices, their breakdown and occurrence of surface separation and stall. A cinema technique of high-image-density particle image velocimetry, in conjunction with dye visualization, allows characterization of the time-averaged and instantaneous states of the flow, in terms of critical points of the near-surface streamlines. These features are related to patterns of surface normal vorticity and velocity fluctuation. Spectral analysis of the naturally occurring unsteadiness of the flow allows definition of the most effective frequencies for small-amplitude perturbation of the wing, which leads to substantial alterations of the aforementioned patterns of flow structure and topology adjacent to the surface.

1/48-scale model of an F-18 aircraft in Flow Visualization Facility (FVF)

NASA Technical Reports Server (NTRS)

1985-01-01

This image shows a plastic 1/48-scale model of an F-18 aircraft inside the 'Water Tunnel' more formally known as the NASA Dryden Flow Visualization Facility. Water is pumped through the tunnel in the direction of normal airflow over the aircraft; then, colored dyes are pumped through tubes with needle valves. The dyes flow back along the airframe and over the airfoils highlighting their aerodynamic characteristics. The aircraft can also be moved through its pitch axis to observe airflow disruptions while simulating actual flight at high angles of attack. The Water Tunnel at NASA's Dryden Flight Research Center, Edwards, CA, became operational in 1983 when Dryden was a Flight Research Facility under the management of the Ames Research Center in Mountain View, CA. As a medium for visualizing fluid flow, water has played a significant role. Its use dates back to Leonardo da Vinci (1452-1519), the Renaissance Italian engineer, architect, painter, and sculptor. In more recent times, water tunnels have assisted the study of complex flows and flow-field interactions on aircraft shapes that generate strong vortex flows. Flow visualization in water tunnels assists in determining the strength of vortices, their location, and possible methods of controlling them. The design of the Dryden Water Tunnel imitated that of the Northrop Corporation's tunnel in Hawthorne, CA. Called the Flow Visualization Facility, the Dryden tunnel was built to assist researchers in understanding the aerodynamics of aircraft configured in such a way that they create strong vortex flows, particularly at high angles of attack. The tunnel provides results that compare well with data from aircraft in actual flight in another fluid-air. Other uses of the tunnel have included study of how such flight hardware as antennas, probes, pylons, parachutes, and experimental fixtures affect airflow. The facility has also been helpful in finding the best locations for emitting smoke from flight vehicles for flow visualization.

1/48-scale model of an F-18 aircraft in Flow Visualization Facility (FVF)

NASA Technical Reports Server (NTRS)

1980-01-01

This short movie clip shows a plastic 1/48-scale model of an F-18 aircraft inside the 'Water Tunnel' more formally known as the NASA Dryden Flow Visualization Facility. Water is pumped through the tunnel in the direction of normal airflow over the aircraft; then, colored dyes are pumped through tubes with needle valves. The dyes flow back along the airframe and over the airfoils highlighting their aerodynamic characteristics. The aircraft can also be moved through its pitch axis to observe airflow disruptions while simulating actual flight at high angles of attack. The Water Tunnel at NASA's Dryden Flight Research Center, Edwards, CA, became operational in 1983 when Dryden was a Flight Research Facility under the management of the Ames Research Center in Mountain View, CA. As a medium for visualizing fluid flow, water has played a significant role. Its use dates back to Leonardo da Vinci (1452-1519), the Renaissance Italian engineer, architect, painter, and sculptor. In more recent times, water tunnels have assisted the study of complex flows and flow-field interactions on aircraft shapes that generate strong vortex flows. Flow visualization in water tunnels assists in determining the strength of vortices, their location, and possible methods of controlling them. The design of the Dryden Water Tunnel imitated that of the Northrop Corporation's tunnel in Hawthorne, CA. Called the Flow Visualization Facility, the Dryden tunnel was built to assist researchers in understanding the aerodynamics of aircraft configured in such a way that they create strong vortex flows, particularly at high angles of attack. The tunnel provides results that compare well with data from aircraft in actual flight in another fluid-air. Other uses of the tunnel have included study of how such flight hardware as antennas, probes, pylons, parachutes, and experimental fixtures affect airflow. The facility has also been helpful in finding the best locations for emitting smoke from flight vehicles for flow visualization.

[Biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5].

PubMed

Hu, Rong; Huang, Jian-Bo; Yang, Zhou-Ping; Cheng, Zi-Zhang; Jing, De-Jun; Huang, Qian-Ming

2011-12-01

With a shaker, this paper studied the characteristics of the biosorption of crystal violet and malachite green by Rhodotorula graminis Y-5 under different adsorption time, initial pH, and temperature, as well as the desorption and recycling use of the dyes. The biosorption of crystal violet and malachite green by R. graminis Y-5 had the peaks (93.8% and 87.7%, respectively) at pH 7.0, dye concentration 50 mg x L(-1), 150 r x min(-1), 30 degrees C, and lasting 10 hours. After desorption, the biosorption rate of crystal violet and malachite green by R. graminis was 85.5% and 78.5%, respectively, indicating that the biosorption of crystal violet and malachite green was reversible, and the recycling use of the dyes by R. graminis was quite good, i. e., the dyes were renewable and could be recycled. Biosorption could be the mechanism of the decolorization of the dyes. The dyes were mostly adsorbed on the R. graminis surface -OH. The adsorption process was fast, efficient, and reversible, suggesting that R. graminis had a high potential for waste water treatment.

Webcam-based flow cytometer using wide-field imaging for low cell number detection at high throughput.

PubMed

Balsam, Joshua; Bruck, Hugh Alan; Rasooly, Avraham

2014-09-07

Here we describe a novel low-cost flow cytometer based on a webcam capable of low cell number detection in a large volume which may overcome the limitations of current flow cytometry. Several key elements have been combined to yield both high throughput and high sensitivity. The first element is a commercially available webcam capable of 187 frames per second video capture at a resolution of 320 × 240 pixels. The second element in this design is a 1 W 450 nm laser module for area-excitation, which combined with the webcam allows for rapid interrogation of a flow field. The final element is a 2D flow-cell which overcomes the flow limitation of hydrodynamic focusing and allows for higher sample throughput in a wider flow field. This cell allows for the linear velocity of target cells to be lower than in a conventional "1D" hydrodynamic focusing flow-cells typically used in cytometry at similar volumetric flow rates. It also allows cells to be imaged at the full frame rate of the webcam. Using this webcam-based flow cytometer with wide-field imaging, it was confirmed that the detection of fluorescently tagged 5 μm polystyrene beads in "1D" hydrodynamic focusing flow-cells was not practical for low cell number detection due to streaking from the motion of the beads, which did not occur with the 2D flow-cell design. The sensitivity and throughput of this webcam-based flow cytometer was then investigated using THP-1 human monocytes stained with SYTO-9 florescent dye in the 2D flow-cell. The flow cytometer was found to be capable of detecting fluorescently tagged cells at concentrations as low as 1 cell per mL at flow rates of 500 μL min(-1) in buffer and in blood. The effectiveness of detection was concentration dependent: at 100 cells per mL 84% of the cells were detected compared to microscopy, 10 cells per mL 79% detected and 1 cell per mL 59% of the cells were detected. With the blood samples spiked to 100 cells per mL, the average concentration for all samples was 91.4 cells per mL, with a 95% confidence interval of 86-97 cells per mL. These low cell concentrations and the large volume capabilities of the system may overcome the limitations of current cytometry, and are applicable to rare cell (such as circulating tumor cell) detection The simplicity and low cost of this device suggests that it may have a potential use in developing point-of-care clinical flow cytometry for resource-poor settings associated with global health.

A high resolution Passive Flux Meter approach based on colorimetric responses

NASA Astrophysics Data System (ADS)

Chardi, K.; Dombrowski, K.; Cho, J.; Hatfield, K.; Newman, M.; Annable, M. D.

2016-12-01

Subsurface water and contaminant mass flux measurements are critical in determining risk, optimizing remediation strategies, and monitoring contaminant attenuation. The standard Passive Flux Meter, hereafter knows as a (PFM), is a well-developed device used for determining and monitoring rates of groundwater and contaminant mass flux in screened wells. The current PFM is a permeable device that contains granular activated carbon impregnated with alcohol tracers which is deployed in a flow field for a designated period of time. Once extracted, sampling requires laboratory analysis to quantify Darcy flux, which can be time consuming and have significant cost. To expedite test results, a modified PFM based on the image analysis of colorimetric responses, herein referred to as a colorimetric Passive Flux Meter (cPFM), was developed. Various dyes and sorbents were selected and evaluated to determine colorimetric response to water flow. Rhodamine, fluorescent yellow, fluorescent orange, and turmeric were the dye candidates while 100% wool and a 35% wool blend with 65% rayon were the sorbent candidates selected for use in the cPFM. Ultraviolet light image analysis was used to calculate average color intensity using ImageJ, a Java-based image processing program. These results were then used to quantify Darcy flux. Error ranges evaluated for Darcy flux using the cPFM are comparable to those with the standard, activated carbon based, PFM. The cPFM has the potential to accomplish the goal of obtaining high resolution Darcy flux data while eliminating high costs and analysis time. Implications of groundwater characteristics, such as PH and contaminant concentrations, on image analysis are to be tested through laboratory analysis followed by field testing of the cPFM.

Adsorption of a reactive dye on chemically modified activated carbons--influence of pH.

PubMed

Orfão, J J M; Silva, A I M; Pereira, J C V; Barata, S A; Fonseca, I M; Faria, P C C; Pereira, M F R

2006-04-15

The surface chemistry of a commercial activated carbon with a slightly basic nature was modified by appropriate treatments in order to obtain two additional samples, respectively with acidic and basic properties, without changing its textural parameters significantly. Different techniques (N2 adsorption at 77 K, temperature programmed desorption, and determination of acidity, basicity, and pH at the point of zero charge) were used to characterize the adsorbents. Kinetic and equilibrium adsorption data of a selected textile reactive dye (Rifafix Red 3BN, C.I. reactive red 241) on the mentioned materials were obtained at the pH values of 2, 7, and 12. The kinetic curves are fitted using the second-order model. The respective rate constants seem to diminish progressively with the initial concentration for the more diluted solutions tested, reaching a constant value at higher concentrations, which depends on the experimental system under consideration (adsorbent and pH). In general, the Langmuir model provides the best fit for the equilibrium data. The different uptakes obtained are discussed in relation to the surface chemical properties of the adsorbents. It is shown that the adsorption of the reactive (anionic) dye on the basic sample (prepared by thermal treatment under H2 flow at 700 degrees C) is favored. This conclusion is explained on the basis of the dispersive and electrostatic interactions involved. Moreover, it is also shown that the optimal adsorption condition for all the activated carbons tested corresponds to solution pH values not higher than the pH(pzc) of the adsorbents, which may be interpreted by taking into account the electrostatic forces present.

Two-Photon Absorption Based Nanoscopic Velocimeter

NASA Astrophysics Data System (ADS)

Wang, Audrey; Abdalrahman, Akrm; Deng, Jianyu; Wang, Guiren

2017-11-01

Most velocimeters in micro/nanofluidics rely on particles as flow tracers, such as micro Particle Image Velocimetry (μPIV). However, for many microflows, such as electrokinetic and near wall flow, magnetophoresis, acoustophoresis, photophoresis and thermophoresis, particles have different velocity from their surrounding fluids. Although most molecular tracer based velocimeters can use neutral dye to measure average velocity, their temporal and spatial resolution are limited. Stimulated emission depletion (STED) based laser-induced fluorescence photobleaching anemometer (LIFPA), i.e. STED-LIFPA has achieved 70 nm spatial resolution. However, STED nanoscopy is very complicated for most users. Here we developed a two-photon absorption LIFPA (TP-LIFPA), which is relatively easier to operate. TP-LIFPA can take advantage of the two-photon microscopy to increase spatial resolution. We use a femtolaser to excite a dye. A microcapillary tube is used to test the feasibility of TP-LIFPA. TP-LIFPA can successfully measure the velocity profile in the capillary. The resolution of TP-LIFPA is estimated to be about 90 nm. The work indicates TP-LIFPA is a new promising nanoscopic velocimeter for interfacial flows, especially within 100 nm at the interfacial area between two phases in the future. The work was supported by NSF under Grant No. MRI CBET-1040227.

Traveltime and dispersion in the Potomac River, Cumberland, Maryland, to Washington, D.C.

USGS Publications Warehouse

Taylor, K.R.; James, R.W.; Helinsky, B.M.

1984-01-01

Data from two traveltime and dispersion studies, using rhodamine dye, are used to develop a generalized procedure for predicting traveltime and downstream concentrations resulting from spillage of water-soluble substances at any point along the Potomac River from Cumberland, Maryland, to Washington, D.C. The procedure will allow the approximate solution to almost any spillage problem concerning traveltime and concentration during periods of relatively steady flow between 50- and 95-percent flow duration. A new procedure for calculating unit peak concentration is derived. The new procedure, based on the similarity in shape of a time-concentration curve and a scalene triangle, allows unit peak concentration to be expressed in terms of the length of the dye cloud. This approach facilitates the linking of peak-concentration attenuation curves for long reaches of rivers which are divided into subreaches for study. An example problem is solved for a hypothetical spill of 20,000 pounds of contaminant at Magnolia, West Virginia. The predicted traveltime of the leading edge, peak concentration, and trailing edge to Point of Rocks, Maryland (110 miles downstream), are 295 , 375, and 540 hours, respectively, for a flow duration of 80 percent. The predicted maximum concentration is 340 micrograms/L. (USGS)

Splitting of turbulent spot in transitional pipe flow

NASA Astrophysics Data System (ADS)

Wu, Xiaohua; Moin, Parviz; Adrian, Ronald J.

2017-11-01

Recent study (Wu et al., PNAS, 1509451112, 2015) demonstrated the feasibility and accuracy of direct computation of the Osborne Reynolds' pipe transition problem without the unphysical, axially periodic boundary condition. Here we use this approach to study the splitting of turbulent spot in transitional pipe flow, a feature first discovered by E.R. Lindgren (Arkiv Fysik 15, 1959). It has been widely believed that spot splitting is a mysterious stochastic process that has general implications on the lifetime and sustainability of wall turbulence. We address the following two questions: (1) What is the dynamics of turbulent spot splitting in pipe transition? Specifically, we look into any possible connection between the instantaneous strain rate field and the spot splitting. (2) How does the passive scalar field behave during the process of pipe spot splitting. In this study, the turbulent spot is introduced at the inlet plane through a sixty degree wide numerical wedge within which fully-developed turbulent profiles are assigned over a short time interval; and the simulation Reynolds numbers are 2400 for a 500 radii long pipe, and 2300 for a 1000 radii long pipe, respectively. Numerical dye is tagged on the imposed turbulent spot at the inlet. Splitting of the imposed turbulent spot is detected very easily. Preliminary analysis of the DNS results seems to suggest that turbulent spot slitting can be easily understood based on instantaneous strain rate field, and such spot splitting may not be relevant in external flows such as the flat-plate boundary layer.

A compact field fluorometer and its application to dye tracing in karst environments

NASA Astrophysics Data System (ADS)

Poulain, Amaël; Rochez, Gaëtan; Van Roy, Jean-Pierre; Dewaide, Lorraine; Hallet, Vincent; De Sadelaer, Geert

2017-08-01

Dye tracing is a classic technique in hydrogeology to investigate surface-water or groundwater flow characteristics, and it is useful for many applications including natural or industrial issues. The Fluo-Green field fluorometer has been successfully tested in a karst environment and is specifically suitable for in-cave karst water monitoring. Karst research often uses dyes to obtain information about groundwater flow in unexplored cave passages. The compact device, alternatively named Fluo-G, meets the requirements of cave media: small (10 × 16 × 21 cm), lightweight (0.75 kg without ballast) and simple in conception. It is easy for cavers to set up and handle compared to other sampling methods. The fluorometer records uranine, turbidity and temperature with a user-defined time-step (1 min - 1 day). Very low energy consumption allows 9,000 measurements with six AA batteries. The device was calibrated and tested in the laboratory and in field conditions in Belgian karst systems. Results are in good fit with other sampling methods: in-situ fluorometers and automatic water sampling plus laboratory analysis. Recording high quality data (breakthrough curves) in karst with in-cave monitoring is valuable to improve knowledge of karst systems. Many hydrological and hydrogeological applications can benefit from such a low-cost and compact device, and finding the best compromise between resources and quality data is essential. Several improvements are possible but preliminary field tests are very promising.

A simple chip free-flow electrophoresis for monosaccharide sensing via supermolecule interaction of boronic acid functionalized quencher and fluorescent dye.

PubMed

Yin, Xiao-Yang; Dong, Jing-Yu; Wang, Hou-Yu; Li, Si; Fan, Liu-Yin; Cao, Cheng-Xi

2013-08-01

Here, a simple micro free-flow electrophoresis (μFFE) was developed for fluorescence sensing of monosaccharide via supermolecule interaction of synthesized boronic acid functionalized benzyl viologen (ο-BBV) and fluorescent dye. The μFFE contained two open electrode cavities and an ion-exchange membrane was sandwiched between two polymethylmethacrylate plates. The experiments demonstrated the following merits of developed μFFE: (i) up to 90.5% of voltage efficiency due to high conductivity of ion-exchange membrane; (ii) a strong ability against influence of bubble produced in two electrodes due to open design of electrode cavities; and (iii) reusable and washable separation chamber (45 mm × 17 mm × 100 μm, 77 μL) avoiding the discard of μFFE due to blockage of solute precipitation in chamber. Remarkably, the μFFE was first designed for the sensing of monosaccharide via the supermolecule interaction of synthesized ο-BBV, fluorescent dye, and monosaccharide. Under the optimized conditions, the minimum concentration of monosaccharide that could be detected was 1 × 10(-11) M. Finally, the developed device was used for the detection of 0.3 mM glucose spiked in human urine. All of the results demonstrated the feasibility of monosaccharide detection via the μFFE. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pore Scale Dynamics of Microemulsion Formation.

PubMed

Unsal, Evren; Broens, Marc; Armstrong, Ryan T

2016-07-19

Experiments in various porous media have shown that multiple parameters come into play when an oleic phase is displaced by an aqueous solution of surfactant. In general, the displacement efficiency is improved when the fluids become quasi-miscible. Understanding the phase behavior oil/water/surfactant systems is important because microemulsion has the ability to generate ultralow interfacial tension (<10(-2) mN m(-1)) that is required for miscibility to occur. Many studies focus on microemulsion formation and the resulting properties under equilibrium conditions. However, the majority of applications where microemulsion is present also involve flow, which has received relatively less attention. It is commonly assumed that the characteristics of an oil/water/surfactant system under flowing conditions are identical to the one under equilibrium conditions. Here, we show that this is not necessarily the case. We studied the equilibrium phase behavior of a model system consisting of n-decane and an aqueous solution of olefin sulfonate surfactant, which has practical applications for enhanced oil recovery. The salt content of the aqueous solution was varied to provide a range of different microemulsion compositions and oil-water interfacial tensions. We then performed microfluidic flow experiments to study the dynamic in situ formation of microemulsion by coinjecting bulk fluids of n-decane and surfactant solution into a T-junction capillary geometry. A solvatochromatic fluorescent dye was used to obtain spatially resolved compositional information. In this way, we visualized the microemulsion formation and the flow of it along with the excess phases. A complex interaction between the flow patterns and the microemulsion properties was observed. The formation of microemulsion influenced the flow regimes, and the flow regimes affected the characteristics of the microemulsion formation. In particular, at low flow rates, slug flow was observed, which had profound consequences on the pore scale mixing behavior and resulting microemulsion properties.

The color removal of dye wastewater by magnesium chloride/red mud (MRM) from aqueous solution.

PubMed

Wang, Qi; Luan, Zhaokun; Wei, Ning; Li, Jin; Liu, Chengxi

2009-10-30

In this study, the MgCl2/red mud system (MRM) was used to investigate the color removal efficiency of dye solutions. Parameters such as the effect of the dosage of red mud (RM) and MgCl2 have been studied. The effect of pH on the conversion rate of Mg2+ has also been studied. The color removal efficiency of MRM was compared with that of PAC/RM and PAC/NaOH. Meanwhile, the color removal efficiency of RM was compared with that of NaOH. The results show that the MRM system can remove more than 98% of the coloring material at a dosage of 25 g RM/L dye solution and a volume of 1.5 mL MgCl2/L dye solution in the decolorization process of reactive dye, acid dye and direct dye. The color removal efficiency was better than PAC/RM and PAC/NaOH system. The adsorption data have been analyzed using Langmuir and Freundlich isotherms. The results indicated that both models provide the best correlation of the experimental data. The decolorization mechanism of MRM was discussed, too. The MRM system was a viable alternative to some of the more conventional forms of chemical treatment of dye solutions and also provided another way to make use of industrial waste red mud.

Novel durable bio-photocatalyst purifiers, a non-heterogeneous mechanism: accelerated entrapped dye degradation into structural polysiloxane-shield nano-reactors.

PubMed

Dastjerdi, Roya; Montazer, Majid; Shahsavan, Shadi; Böttcher, Horst; Moghadam, M B; Sarsour, Jamal

2013-01-01

This research has designed innovative Ag/TiO(2) polysiloxane-shield nano-reactors on the PET fabric to develop novel durable bio-photocatalyst purifiers. To create these very fine nano-reactors, oppositely surface charged multiple size nanoparticles have been applied accompanied with a crosslinkable amino-functionalized polysiloxane (XPs) emulsion. Investigation of photocatalytic dye decolorization efficiency revealed a non-heterogeneous mechanism including an accelerated degradation of entrapped dye molecules into the structural polysiloxane-shield nano-reactors. In fact, dye molecules can be adsorbed by both Ag and XPs due to their electrostatic interactions and/or even via forming a complex with them especially with silver NPs. The absorbed dye and active oxygen species generated by TiO(2) were entrapped by polysiloxane shelter and the presence of silver nanoparticles further attract the negative oxygen species closer to the adsorbed dye molecules. In this way, the dye molecules are in close contact with concentrated active oxygen species into the created nano-reactors. This provides an accelerated degradation of dye molecules. This non-heterogeneous mechanism has been detected on the sample containing all of the three components. Increasing the concentration of Ag and XPs accelerated the second step beginning with an enhanced rate. Further, the treated samples also showed an excellent antibacterial activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Adsorption of dyes using different types of clay: a review

NASA Astrophysics Data System (ADS)

Adeyemo, Aderonke Ajibola; Adeoye, Idowu Olatunbosun; Bello, Olugbenga Solomon

2017-05-01

Increasing amount of dyes in the ecosystem particularly in wastewater has propelled the search for more efficient low-cost adsorbents. The effective use of the sorption properties (high surface area and surface chemistry, lack of toxicity and potential for ion exchange) of different clays as adsorbents for the removal of different type of dyes (basic, acidic, reactive) from water and wastewater as potential alternatives to activated carbons has recently received widespread attention because of the environmental-friendly nature of clay materials. Insights into the efficiencies of raw and modified/activated clay adsorbents and ways of improving their efficiencies to obtain better results are discussed. Acid-modified clay resulted in higher rate of dye adsorption and an increased surface area and porosity (49.05 mm2 and 53.4 %). Base-modified clay has lower adsorption capacities, while ZnCl2-modified clay had the least rate of adsorption with a surface area of 44.3 mm2 and porosity of 43.4 %. This review also explores the grey areas of the adsorption properties of the raw clays and the improved performance of activated/modified clay materials with particular reference to the effects of pH, temperature, initial dye concentration and adsorbent dosage on the adsorption capacities of the clays. Various challenges encountered in using clay materials are highlighted and a number of future prospects for the adsorbents are proposed.

Plasmachemical degradation of azo dyes by humid air plasma: Yellow Supranol 4 GL, Scarlet Red Nylosan F3 GL and industrial waste.

PubMed

Abdelmalek, F; Gharbi, S; Benstaali, B; Addou, A; Brisset, J L

2004-05-01

A recent non-thermal plasma technique (i.e., a gliding arc discharge which generates reactive species at atmospheric pressure) is tested for pollution abatement of dyes dispersed in synthetic solutions and industrial effluents. Yellow Supranol 4 GL (YS) and Scarlet Red Nylosan F3 GL (SRN) are toxic synthetic dyes widely used in the Algerian textile industry and frequently present in liquid wastes of manufacture plants. Classical removal treatment processes are not efficient enough, so that the presence of dyes in liquid effluents may cause serious environmental problems, in connection with reusing waste waters for irrigation. The degradation processes achieved by the oxidising species formed in the plasma are followed by UV/VIS spectroscopy and by chemical oxygen demand measurements. They are almost complete (i.e., 92.5% for YS and 90% for dilute SRN) and rapidly follow pseudo-first-order laws, with overall estimated rate constants 3 x 10(-4) and 4 x 10(-4)s-1 for YS and SRN, respectively. The degradation rate constant for the industrial mixture (i.e., k = 1.45 x 10(-3)s-1) is a mean value for two consecutive steps (210(-3) and 6 x 10(-5)s-1) measured at the absorption peaks of the major constituent dyes, YS and SRN.

Massive radius-dependent flow slippage in carbon nanotubes.

PubMed

Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

2016-09-08

Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water-carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid-liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter.

Massive radius-dependent flow slippage in carbon nanotubes

NASA Astrophysics Data System (ADS)

Secchi, Eleonora; Marbach, Sophie; Niguès, Antoine; Stein, Derek; Siria, Alessandro; Bocquet, Lydéric

2016-09-01

Measurements and simulations have found that water moves through carbon nanotubes at exceptionally high rates owing to nearly frictionless interfaces. These observations have stimulated interest in nanotube-based membranes for applications including desalination, nano-filtration and energy harvesting, yet the exact mechanisms of water transport inside the nanotubes and at the water-carbon interface continue to be debated because existing theories do not provide a satisfactory explanation for the limited number of experimental results available so far. This lack of experimental results arises because, even though controlled and systematic studies have explored transport through individual nanotubes, none has met the considerable technical challenge of unambiguously measuring the permeability of a single nanotube. Here we show that the pressure-driven flow rate through individual nanotubes can be determined with unprecedented sensitivity and without dyes from the hydrodynamics of water jets as they emerge from single nanotubes into a surrounding fluid. Our measurements reveal unexpectedly large and radius-dependent surface slippage in carbon nanotubes, and no slippage in boron nitride nanotubes that are crystallographically similar to carbon nanotubes, but electronically different. This pronounced contrast between the two systems must originate from subtle differences in the atomic-scale details of their solid-liquid interfaces, illustrating that nanofluidics is the frontier at which the continuum picture of fluid mechanics meets the atomic nature of matter.

Microfluidics-based microbubbles in methylene blue solution for photoacoustic and ultrasound imaging

NASA Astrophysics Data System (ADS)

Das, Dhiman; Sivasubramanian, Kathyayini; Yang, Chun; Pramanik, Manojit

2018-02-01

Contrast agents which can be used for more than one bio-imaging technique has gained a lot of attention from researchers in recent years. In this work, a microfluidic device employing a flow-focusing junction, is used for the continuous generation of monodisperse nitrogen microbubbles in methylene blue, an optically absorbing organic dye, for dual-modal photoacoustic and ultrasound imaging. Using an external phase of polyoxyethylene glycol 40 stearate (PEG 40), a non-ionic surfactant, and 50% glycerol solution at a flow rate of 1 ml/hr and gas pressure at 1.75 bar, monodisperse nitrogen microbubbles of diameter 7 microns were obtained. The external phase also contained methylene blue hydrate at a concentration of 1 gm/litre. The monodisperse microbubbles produced a strong ultrasound signal as expected. It was observed that the signal-to-noise (SNR) ratio of the photoacoustic signal for the methylene blue solution in the presence of the monodisperse microbubbles was 68.6% lower than that of methylene blue solution in the absence of microbubbles. This work is of significance because using microfluidics, we can precisely control the bubbles' production rate and bubble size which increases ultrasound imaging efficiency. A uniform size distribution of the bubbles will have narrower resonance frequency bandwidth which will respond well to specific ultrasound frequencies.

Scanning wave photopolymerization enables dye-free alignment patterning of liquid crystals

PubMed Central

Hisano, Kyohei; Aizawa, Miho; Ishizu, Masaki; Kurata, Yosuke; Nakano, Wataru; Akamatsu, Norihisa; Barrett, Christopher J.; Shishido, Atsushi

2017-01-01

Hierarchical control of two-dimensional (2D) molecular alignment patterns over large areas is essential for designing high-functional organic materials and devices. However, even by the most powerful current methods, dye molecules that discolor and destabilize the materials need to be doped in, complicating the process. We present a dye-free alignment patterning technique, based on a scanning wave photopolymerization (SWaP) concept, that achieves a spatial light–triggered mass flow to direct molecular order using scanning light to propagate the wavefront. This enables one to generate macroscopic, arbitrary 2D alignment patterns in a wide variety of optically transparent polymer films from various polymerizable mesogens with sufficiently high birefringence (>0.1) merely by single-step photopolymerization, without alignment layers or polarized light sources. A set of 150,000 arrays of a radial alignment pattern with a size of 27.4 μm × 27.4 μm were successfully inscribed by SWaP, in which each individual pattern is smaller by a factor of 104 than that achievable by conventional photoalignment methods. This dye-free inscription of microscopic, complex alignment patterns over large areas provides a new pathway for designing higher-performance optical and mechanical devices. PMID:29152567

Redefining Molecular Amphipathicity in Reversing the "Coffee-Ring Effect": Implications for Single Base Mutation Detection.

PubMed

Huang, Chi; Wang, Jie; Lv, Xiaobo; Liu, Liu; Liang, Ling; Hu, Wei; Luo, Changliang; Wang, Fubing; Yuan, Quan

2018-05-21

The "coffee ring effect" is a natural phenomenon where sessile drops leave ring-shaped structures on solid surfaces upon drying. It drives non-uniform deposition of suspended compounds on substrates, which adversely affects many processes, including surface-assisted biosensing and molecular self-assembly. In this study, we describe how the coffee ring effect can be eliminated by controlling the amphipathicity of the suspended compounds, for example DNA modified with hydrophobic dye. Specifically, nuclease digestion of the hydrophilic DNA end converts the dye-labeled molecule into an amphipathic molecule (one with comparably weighted hydrophobic and hydrophilic ends) and reverses the coffee ring effect and results in uniform disc-shaped feature deposition of the dye. The amphipathic product decreases the surface tension of the sessile drops and induces Marangoni flow, which drives the uniform distribution of the amphipathic dye-labeled product in the drops. As proof-of-concept, this strategy was used in a novel enzymatic amplification method for biosensing to eliminate the coffee ring effect on a nitrocellulose membrane and increase assay reliability and sensitivity. Importantly, the reported strategy for eliminating the coffee ring effect can be extended to other sessile drop systems for potentially improving assay reliability, and sensitivity.

Balloon borne in-situ detection of OH in the stratosphere from 37 to 23 km

NASA Technical Reports Server (NTRS)

Stimpfle, R. M.; Lapson, L. B.; Wennberg, P. O.; Anderson, J. G.

1989-01-01

The OH number density in the stratosphere has been measured over the altitude interval of 37 to 23 km at midday via a balloon-borne gondola launched from Palestine, Texas on July 6, 1988. OH radicals are detected with a laser-induced fluorescence instrument employing a 17-kHz-repetition-rate copper vapor laser-pumped dye laser optically coupled to an enclosed flow, in-situ sampling chamber. OH abundances ranged from 88 + or - 3l pptv in the 36 to 35 km interval to 0.9 + or - 0.8 pptv in the 24 to 23 km interval. The stated uncertainty includes that from both measurement precision and accuracy. Simultaneous detection of ozone and water vapor densities was carried out with separate on-board instruments.

Photoinitated charge separation in a hybrid titanium dioxide metalloporphyrin peptide material

NASA Astrophysics Data System (ADS)

Fry, H. Christopher; Liu, Yuzi; Dimitrijevic, Nada M.; Rajh, Tijana

2014-08-01

In natural systems, electron flow is mediated by proteins that spatially organize donor and acceptor molecules with great precision. Achieving this guided, directional flow of information is a desirable feature in photovoltaic media. Here, we design self-assembled peptide materials that organize multiple electronic components capable of performing photoinduced charge separation. Two peptides, c16-AHL3K3-CO2H and c16-AHL3K9-CO2H, self-assemble into fibres and provide a scaffold capable of binding a metalloporphyrin via histidine axial ligation and mineralize titanium dioxide (TiO2) on the lysine-rich surface of the resulting fibrous structures. Electron paramagnetic resonance studies of this self-assembled material under continuous light excitation demonstrate charge separation induced by excitation of the metalloporphyrin and mediated by the peptide assembly structure. This approach to dye-sensitized semiconducting materials offers a means to spatially control the dye molecule with respect to the semiconducting material through careful, strategic peptide design.

Mechanistic understanding of monosaccharide-air flow battery electrochemistry

NASA Astrophysics Data System (ADS)

Scott, Daniel M.; Tsang, Tsz Ho; Chetty, Leticia; Aloi, Sekotilani; Liaw, Bor Yann

Recently, an inexpensive monosaccharide-air flow battery configuration has been demonstrated to utilize a strong base and a mediator redox dye to harness electrical power from the partial oxidation of glucose. Here the mechanistic understanding of glucose oxidation in this unique glucose-air power source is further explored by acid-base titration experiments, 13C NMR, and comparison of results from chemically different redox mediators (indigo carmine vs. methyl viologen) and sugars (fructose vs. glucose) via studies using electrochemical techniques. Titration results indicate that gluconic acid is the main product of the cell reaction, as supported by evidence in the 13C NMR spectra. Using indigo carmine as the mediator dye and fructose as the energy source, an abiotic cell configuration generates a power density of 1.66 mW cm -2, which is greater than that produced from glucose under similar conditions (ca. 1.28 mW cm -2). A faster transition from fructose into the ene-diol intermediate than from glucose likely contributed to this difference in power density.

Optimization and Standardization of Fluorescent Cell Barcoding for Multiplexed Flow Cytometric Phenotyping

PubMed Central

Giudice, Valentina; Feng, Xingmin; Kajigaya, Sachiko; Young, Neal S.; Biancotto, Angélique

2017-01-01

Fluorescent cell barcoding (FCB) is a cell-based multiplexing technique for high-throughput flow cytometry. Barcoded samples can be stained and acquired collectively, minimizing staining variability and antibody consumption, and decreasing required sample volumes. Combined with functional measurements, FCB can be used for drug screening, signaling profiling, and cytokine detection, but technical issues are present. We optimized the FCB technique for routine utilization using DyLight 350, DyLight 800, Pacific Orange, and CBD500 for barcoding six, nine, or 36 human peripheral blood specimens. Working concentrations of FCB dyes ranging from 0 to 500 μg/ml were tested, and viability dye staining was optimized to increase robustness of data. A five-color staining with surface markers for Vβ usage analysis in CD4+ and CD8+ T cells was achieved in combination with nine sample barcoding. We provide improvements of the FCB technique that should be useful for multiplex drug screening and for lymphocyte characterization and perturbations in the diagnosis and during the course of disease. PMID:28692789

Effect of SBR feeding strategy and feed composition on the stability of aerobic granular sludge in the treatment of a simulated textile wastewater.

PubMed

Franca, R D G; Ortigueira, J; Pinheiro, H M; Lourenço, N D

2017-09-01

Treatment of the highly polluting and variable textile industry wastewater using aerobic granular sludge (AGS) sequencing batch reactors (SBRs) has been recently suggested. Aiming to develop this technology application, two feeding strategies were compared regarding the capacity of anaerobic-aerobic SBRs to deal with disturbances in the composition of the simulated textile wastewater feed. Both a statically fed, anaerobic-aerobic SBR and an anaerobic plug-flow fed, anaerobic-aerobic SBR could cope with shocks of high azo dye concentration and organic load, the overall chemical oxygen demand and color removal yields being rapidly restored to 80%. Yet, subsequent azo dye metabolite bioconversion was not observed, along the 315-day run. Moreover, switching from a starch-based substrate to acetate in the feed composition deteriorated AGS stability. Overall, the plug-flow fed SBR recovered more rapidly from the imposed disturbances. Further research is needed towards guaranteeing long-term AGS stability during the treatment of textile wastewater.

Dye-sensitized MIL-101 metal organic frameworks loaded with Ni/NiOx nanoparticles for efficient visible-light-driven hydrogen generation

NASA Astrophysics Data System (ADS)

Liu, Xin-Ling; Wang, Rong; Zhang, Ming-Yi; Yuan, Yu-Peng; Xue, Can

2015-10-01

The Ni/NiOx particles were in situ photodeposited on MIL-101 metal organic frameworks as catalysts for boosting H2 generation from Erythrosin B dye sensitization under visible-light irradiation. The highest H2 production rate of 125 μmol h-1 was achieved from the system containing 5 wt. % Ni-loaded MIL-101 (20 mg) and 30 mg Erythrosin B dye. Moreover, the Ni/NiOx catalysts show excellent stability for long-term photocatalytic reaction. The enhancement on H2 generation is attributed to the efficient charge transfer from photoexcited dye to the Ni catalyst via MIL-101. Our results demonstrate that the economical Ni/NiOx particles are durable and active catalysts for photocatalytic H2 generation.

Photoinduced electron transfer of oxazine 1/TiO2 nanoparticles at single molecule level by using confocal fluorescence microscopy.

PubMed

Chen, Yi-Ju; Tzeng, Hsin-Yu; Fan, Hsiu-Fang; Chen, Ming-Shiang; Huang, Jer-Shing; Lin, King-Chuen

2010-06-01

Kinetics of photoinduced electron transfer (ET) from oxazine 1 dye to TiO(2) nanoparticles (NPs) surface is studied at a single molecule level by using confocal fluorescence microscopy. Upon irradiation with a pulsed laser at 630 nm, the fluorescence lifetimes sampled among 100 different dye molecules are determined to yield an average lifetime of 2.9 +/- 0.3 ns, which is close to the value of 3.0 +/- 0.6 ns measured on the bare coverslip. The lifetime proximity suggests that most interfacial electron transfer (IFET) processes for the current system are inefficient, probably caused by physisorption between dye and the TiO(2) film. However, there might exist some molecules which are quenched before fluorescing and fail to be detected. With the aid of autocorrelation analysis under a three-level energy system, the IFET kinetics of single dye molecules in the conduction band of TiO(2) NPs is evaluated to be (1.0 +/- 0.1) x 10(4) s(-1) averaged over 100 single molecules and the back ET rate constant is 4.7 +/- 0.9 s(-1). When a thicker TiO(2) film is substituted, the resultant kinetic data do not make a significant difference. The trend of IFET efficacy agrees with the method of fluorescence lifetime measurements. The obtained forward ET rate constants are about ten times smaller than the photovoltage response measured in an assembled dye-sensitized solar cell. The discrepancy is discussed. The inhomogeneous and fluctuation characters for the IFET process are attributed to microenvironment variation for each single molecule. The obtained ET rates are much slower than the fluorescence relaxation. Such a small ET quantum yield is yet feasibly detectable at a single molecule level.

Decolorization of acid, disperse and reactive dyes by Trametes versicolor CBR43.

PubMed

Yang, Seung-Ok; Sodaneath, Hong; Lee, Jung-In; Jung, Hyekyeng; Choi, Jin-Hee; Ryu, Hee Wook; Cho, Kyung-Suk

2017-07-29

The mycoremediation has been considered as a promising method for decolorizing dye wastewater. To explore new bioresource for mycoremediation, a new white-rot fungus that could decolorize various dyes commonly used in textile industries was isolated, and its ligninolytic enzyme activity and decolorization capacity were characterized. The isolated CBR43 was identified as Trametes versicolor based on the morphological properties of its fruit body and spores, as well as through partial 18S rDNA gene sequences. Isolated CBR43 displayed high activities of laccase and Mn-dependent peroxidase, whereas its lignin peroxidase activity was relatively low. These ligninolytic enzyme activities in potato dextrose broth (PDB) medium were enhanced by the addition of yeast extract (1-10 g L -1 ). In particular, lignin peroxidase activity was increased more than 5 times in the PDB medium amended with 10 g L -1 of yeast extract. The CBR43 decolorized more than 90% of 200 mg L -1 acid dyes (red 114, blue 62 and black 172) and reactive dyes (red 120, blue 4, orange 16 and black 5) within 6 days in the PDB medium. CBR43 decolorized 67% of 200 mg L -1 acid orange 7 within 9 days. The decolorization efficiencies for disperse dyes (red 1, orange 3 and black 1) were 51-80% within 9 days. The CBR43 could effectively decolorize high concentrations of acid blue 62 and acid black 172 (500-700 mg L -1 ). The maximum dye decolorization rate was obtained at 28°C, pH 5, and 150 rpm in the PDB medium. T. versicolor CBR43 had high laccase and Mn-dependent peroxidase activities, and could decolorize a wide variety of dyes such as acid, disperse and reactive textile dyes. This fungus had decolorizing activities of azo-type dyes as well as anthraquinone-type dyes. T. versicolor CBR43 is one of promising bioresources for the decolorization of textile wastewater including various dyes.

Development of thermosensitive chitosan/glicerophospate injectable in situ gelling solutions for potential application in intraoperative fluorescence imaging and local therapy of hepatocellular carcinoma: a preliminary study.

PubMed

Salis, Andrea; Rassu, Giovanna; Budai-Szűcs, Maria; Benzoni, Ilaria; Csányi, Erzsébet; Berkó, Szilvia; Maestri, Marcello; Dionigi, Paolo; Porcu, Elena P; Gavini, Elisabetta; Giunchedi, Paolo

2015-01-01

Thermosensitive chitosan/glycerophosphate (C/GP) solutions exhibiting sol-gel transition around body temperature were prepared to develop a class of injectable hydrogel platforms for the imaging and loco-regional treatment of hepatocellular carcinoma (HCC). Indocyanine green (ICG) was loaded in the thermosensitive solutions in order to assess their potential for the detection of tumor nodules by fluorescence. The gel formation of these formulations as well as their gelling time, injectability, compactness and resistance of gel structure, gelling temperature, storage conditions, biodegradability, and in vitro dye release behavior were investigated. Ex vivo studies were carried out for preliminary evaluation using an isolated bovine liver. Gel strengths and gelation rates increased with the cross-link density between C and GP. These behaviors are more evident for C/GP solutions, which displayed a gel-like precipitation at 4°C. Furthermore, formulations with the lowest cross-link density between C and GP exhibited the best injectability due to a lower resistance to flow. The loading of the dye did not influence the gelation rate. ICG was not released from the hydrogels because of a strong electrostatic interaction between C and ICG. Ex vivo preliminary studies revealed that these injectable formulations remain in correspondence of the injected site. The developed ICG-loaded hydrogels have the potential for intraoperative fluorescence imaging and local therapy of HCC as embolic agents. They form in situ compact gels and have a good potential for filling vessels and/or body cavities.

Tracer adsorption in sand-tank experiments of saltwater up-coning

NASA Astrophysics Data System (ADS)

Jakovovic, Danica; Post, Vincent E. A.; Werner, Adrian D.; Männicke, Oliver; Hutson, John L.; Simmons, Craig T.

2012-01-01

SummaryThis study aims to substantiate otherwise unresolved double-peaked plumes produced in recent saltwater up-coning experiments (see Jakovovic et al. (2011), Numerical modelling of saltwater up-coning: Comparison with experimental laboratory observations, Journal of Hydrology 402, 261-273) through additional laboratory testing and numerical modelling. Laboratory experimentation successfully reproduced the double-peaked plume demonstrating that this phenomenon was not an experimental nuance in previous experiments. Numerical modelling by Jakovovic et al. (2011) was extended by considering adsorption effects, which were needed to explain the observed up-coning double peaks of both previous and current laboratory experiments. A linear adsorption isotherm was applied in predicting dye tracer (Rhodamine WT) behaviour in the sand-tank experiments using adsorption parameters obtained experimentally. The same adsorption parameters were tested on all laboratory experiments and it was found that adsorption had insignificant effect on experiments with high pumping rates. However, low pumping rates produced pronounced spatial velocity variations within the dense salt plume beneath the pumping well, with velocities within the plume increasing from the centre of the plume towards the interface. The dye tracer was retarded relative to the salt and was transported preferentially along the higher-velocity paths (i.e. along the edges of the salt plume) towards the well forming double-peaked up-coning patterns. This illustrates the sensitive adsorptive nature of Rhodamine WT and that care should be taken when it is used in similar sand-tank experiments. Observations from this study offer insight into the separation of chemicals in natural systems due to different adsorption characteristics and under conditions of density-dependent flow.

Pulse infusion thrombolysis (PIT) for large intracoronary thrombus: preventive effect against the 'no flow' phenomenon in revascularization therapy for acute myocardial infarction.

PubMed

Saito, T; Hokimoto, S; Ishibashi, F; Noda, K; Oshima, S

2001-02-01

Because large thrombus is a limitation for revascularization in acute myocardial infarction (AMI), the present study evaluated the effectiveness of pulse infusion thrombolysis (PIT) in patients with an AMI with a large (>15 mm) coronary thrombus, focusing on the occurrence of the 'no flow' phenomenon. The retrospective study compared patients treated before (1988-95; Group A, n=74) and after (1996-99; Group B, n=40) the use of PIT, using the following parameters: lesion success (<50% stenosis during 30-min observation), procedural success (lesion success plus TIMI grade 3 flow), procedural no flow (TIMI grade 0 flow during the procedure with 'back and forth movement' of contrast dye after lesion success), persistent no flow (consistent no flow without any flow improvement at the final visualization despite intensive treatment), reocclusion rate and in-hospital death. Group B was significantly better than Group A in procedural success (90% vs 66%; p=0.005), procedural 'no flow' (51% vs 15%; p<0.001), and persistent 'no flow' (34% vs 10%; p<0.05). Subgroup comparison was performed among the following groups: Direct-BA group (n=44): treated with mechanical angioplasty alone; ICT-BA group (n=40): treated with prior intracoronary thrombolysis and angioplasty; and PIT-BA group (n=30): treated with PIT and angioplasty. There were no differences in thrombus length and lesion success among these 3 groups. Procedural success was best achieved in PIT-BA: 97% vs 52% for Direct-BA (p=0.003) and 68% for ICT-BA (p=0.009). Procedural 'no flow' was least in PIT-BA: 50% vs 3.3% for Direct-BA (p=0.003) and 25% vs 3.3% for ICT-BA (p=0.042). Persistent 'no flow' was less frequent in PIT-BA than Direct-BA: 32% vs 3.3% (p=0.009). However, the difference between ICT-BA and Direct-BA was insignificant: 13% vs 3.3% (p=0.53). There were no differences in reocclusion rate and in-hospital death among the 3 subgroups. And there were no differences between Direct-BA and ICT-BA in any parameters. PIT was effective in preventing 'no flow' in the mechanical revasculalization for AMI especially those cases with a large thrombus.

Photoactive dye-enhanced tissue ablation for endoscopic laser prostatectomy.

PubMed

Ahn, Minwoo; Hau, Nguyen Trung; Van Phuc, Nguyen; Oh, Junghwan; Kang, Hyun Wook

2014-11-01

Laser light has been widely used as a surgical tool to treat benign prostate hyperplasia (BPH) over 20 years. Recently, application of high laser power up to 200 W was often reported to swiftly remove a large amount of prostatic tissue. The purpose of this study was to validate the feasibility of photoactive dye injection to enhance light absorption and eventually to facilitate tissue vaporization with low laser power. Chicken breast tissue was selected as a target tissue due to minimal optical absorption at the visible wavelength. Four biocompatible photoactive dyes, including amaranth (AR), black dye (BD), hemoglobin powder (HP), and endoscopic marker (EM), were selected and tested in vitro with a customized 532 nm laser system with radiant exposure ranging from 0.9 to 3.9 J/cm(2) . Light absorbance and ablation threshold were measured with UV-Vis spectrometer and Probit analysis, respectively, and compared to feature the function of the injected dyes. Ablation performance with dye-injection was evaluated in light of radiant exposure, dye concentration, and number of injection. Higher light absorption by injected dyes led to lower ablation threshold as well as more efficient tissue removal in the order of AR, BD, HP, and EM. Regardless of the injected dyes, ablation efficiency principally increased with radiant exposure, dye concentration, and number of injection. Among the dyes, AR created the highest ablation rate of 44.2 ± 0.2 µm/pulse due to higher absorbance and lower ablation threshold. High aspect ratios up to 7.1 ± 0.4 entailed saturation behavior in the tissue ablation injected with AR and BD, possibly resulting from plume shielding and increased scattering due to coagulation. Preliminary tests on canine prostate with a hydraulic injection system demonstrated that 80 W with dye injection yielded comparable ablation efficiency to 120 W with no injection, indicating 33% reduced laser power with almost equivalent performance. Due to efficient coupling of optical energy, pre-injection of photoactive dyes promoted the degree of tissue removal during laser irradiation. Further studies will investigate spatial distribution of dyes and optimal injecting pressure to govern the extent of dye-assisted ablation in a predictable manner. In-depth comprehension on photoactive dye-enhanced tissue ablation can help accomplish efficient and safe laser vaporization for BPH with low power application. © 2014 Wiley Periodicals, Inc.

ECN-33298-03

NASA Image and Video Library

1985-12-19

This image shows a plastic 1/48-scale model of an F-18 aircraft inside the "Water Tunnel" more formally known as the NASA Dryden Flow Visualization Facility. Water is pumped through the tunnel in the direction of normal airflow over the aircraft; then, colored dyes are pumped through tubes with needle valves. The dyes flow back along the airframe and over the airfoils highlighting their aerodynamic characteristics. The aircraft can also be moved through its pitch axis to observe airflow disruptions while simulating actual flight at high angles of attack. The Water Tunnel at NASA's Dryden Flight Research Center, Edwards, CA, became operational in 1983 when Dryden was a Flight Research Facility under the management of the Ames Research Center in Mountain View, CA. As a medium for visualizing fluid flow, water has played a significant role. Its use dates back to Leonardo da Vinci (1452-1519), the Renaissance Italian engineer, architect, painter, and sculptor. In more recent times, water tunnels have assisted the study of complex flows and flow-field interactions on aircraft shapes that generate strong vortex flows. Flow visualization in water tunnels assists in determining the strength of vortices, their location, and possible methods of controlling them. The design of the Dryden Water Tunnel imitated that of the Northrop Corporation's tunnel in Hawthorne, CA. Called the Flow Visualization Facility, the Dryden tunnel was built to assist researchers in understanding the aerodynamics of aircraft configured in such a way that they create strong vortex flows, particularly at high angles of attack. The tunnel provides results that compare well with data from aircraft in actual flight in another fluid-air. Other uses of the tunnel have included study of how such flight hardware as antennas, probes, pylons, parachutes, and experimental fixtures affect airflow. The facility has also been helpful in finding the best locations for emitting smoke from flight vehicles for flow vi

[Contents mensuration of total alkaloid in Uncaria rhynchophylla by acid dye colorimetry].

PubMed

Zeng, Chang-qing; Luo, Bei-liang

2007-08-01

To investigate the method of determination of total alkaloids Uncaria rhynchophylla. The Contents of total Alkaloid were determined by Acid dye Colorimetry. Acid dye color conditions: pH3.6 buffer 5.0 ml, bromocresol green liquid 5.0 ml; chloroform extraction three times, each time was exeracted for 2 minutes, put it aside for at least 5 minutes for the determination of the best method. Rhynchophylline 6.018 microg - 108.324 microg in the linear range, Recoveriys rate was 97.19%, RSD was 1.34% (n = 6). The method is simple, highly sensitive and reproducible.

An eco-friendly dyeing of woolen yarn by Terminalia chebula extract with evaluations of kinetic and adsorption characteristics.

PubMed

Shabbir, Mohd; Rather, Luqman Jameel; Shahid-Ul-Islam; Bukhari, Mohd Nadeem; Shahid, Mohd; Ali Khan, Mohd; Mohammad, Faqeer

2016-05-01

In the present study Terminalia chebula was used as an eco-friendly natural colorant for sustainable textile coloration of woolen yarn with primary emphasis on thermodynamic and kinetic adsorption aspects of dyeing processes. Polyphenols and ellagitannins are the main coloring components of the dye extract. Assessment of the effect of pH on dye adsorption showed an increase in adsorption capacity with decreasing pH. Effect of temperature on dye adsorption showed 80 °C as optimum temperature for wool dyeing with T. chebula dye extract. Two kinetic equations, namely pseudo first-order and pseudo second-order equations, were employed to investigate the adsorption rates. Pseudo second-order model provided the best fit (R (2) = 0.9908) to the experimental data. The equilibrium adsorption data were fitted by Freundlich and Langmuir isotherm models. The adsorption behavior accorded well (R (2) = 0.9937) with Langmuir isotherm model. Variety of eco-friendly and sustainable shades were developed in combination with small amount of metallic mordants and assessed in terms of colorimetric (CIEL(∗) a (∗) b (∗) and K/S) properties measured using spectrophotometer under D65 illuminant (10° standard observer). The fastness properties of dyed woolen yarn against light, washing, dry and wet rubbing were also evaluated.

An eco-friendly dyeing of woolen yarn by Terminalia chebula extract with evaluations of kinetic and adsorption characteristics

PubMed Central

Shabbir, Mohd; Rather, Luqman Jameel; Shahid-ul-Islam; Bukhari, Mohd Nadeem; Shahid, Mohd; Ali Khan, Mohd; Mohammad, Faqeer

2016-01-01

In the present study Terminalia chebula was used as an eco-friendly natural colorant for sustainable textile coloration of woolen yarn with primary emphasis on thermodynamic and kinetic adsorption aspects of dyeing processes. Polyphenols and ellagitannins are the main coloring components of the dye extract. Assessment of the effect of pH on dye adsorption showed an increase in adsorption capacity with decreasing pH. Effect of temperature on dye adsorption showed 80 °C as optimum temperature for wool dyeing with T. chebula dye extract. Two kinetic equations, namely pseudo first-order and pseudo second-order equations, were employed to investigate the adsorption rates. Pseudo second-order model provided the best fit (R2 = 0.9908) to the experimental data. The equilibrium adsorption data were fitted by Freundlich and Langmuir isotherm models. The adsorption behavior accorded well (R2 = 0.9937) with Langmuir isotherm model. Variety of eco-friendly and sustainable shades were developed in combination with small amount of metallic mordants and assessed in terms of colorimetric (CIEL∗a∗b∗ and K/S) properties measured using spectrophotometer under D65 illuminant (10° standard observer). The fastness properties of dyed woolen yarn against light, washing, dry and wet rubbing were also evaluated. PMID:27222752

Extractive biodecolorization of triphenylmethane dyes in cloud point system by Aeromonas hydrophila DN322p.

PubMed

Pan, Tao; Ren, Suizhou; Xu, Meiying; Sun, Guoping; Guo, Jun

2013-07-01

The biological treatment of triphenylmethane dyes is an important issue. Most microbes have limited practical application because they cannot completely detoxicate these dyes. In this study, the extractive biodecolorization of triphenylmethane dyes by Aeromonas hydrophila DN322p was carried out by introducing the cloud point system. The cloud point system is composed of a mixture of nonionic surfactants (20 g/L) Brij 30 and Tergitol TMN-3 in equal proportions. After the decolorization of crystal violet, a higher wet cell weight was obtained in the cloud point system than that of the control system. Based on the results of thin-layer chromatography, the residual crystal violet and its decolorized product, leuco crystal violet, preferred to partition into the coacervate phase. Therefore, the detoxification of the dilute phase was achieved, which indicated that the dilute phase could be discharged without causing dye pollution. The extractive biodecolorization of three other triphenylmethane dyes was also examined in this system. The decolorization of malachite green and brilliant green was similar to that of crystal violet. Only ethyl violet achieved a poor decolorization rate because DN322p decolorized it via adsorption but did not convert it into its leuco form. This study provides potential application of biological treatment in triphenylmethane dye wastewater.

Decolorization of industrial synthetic dyes using engineered Pseudomonas putida cells with surface-immobilized bacterial laccase

PubMed Central

2012-01-01

Background Microbial laccases are highly useful in textile effluent dye biodegradation. However, the bioavailability of cellularly expressed or purified laccases in continuous operations is usually limited by mass transfer impediment or enzyme regeneration difficulty. Therefore, this study develops a regenerable bacterial surface-displaying system for industrial synthetic dye decolorization, and evaluates its effects on independent and continuous operations. Results A bacterial laccase (WlacD) was engineered onto the cell surface of the solvent-tolerant bacterium Pseudomonas putida to construct a whole-cell biocatalyst. Ice nucleation protein (InaQ) anchor was employed, and the ability of 1 to 3 tandemly aligned N-terminal repeats to direct WlacD display were compared. Immobilized WlacD was determined to be surface-displayed in functional form using Western blot analysis, immunofluorescence microscopy, flow cytometry, and whole-cell enzymatic activity assay. Engineered P. putida cells were then applied to decolorize the anthraquinone dye Acid Green (AG) 25 and diazo-dye Acid Red (AR) 18. The results showed that decolorization of both dyes is Cu2+- and mediator-independent, with an optimum temperature of 35°C and pH of 3.0, and can be stably performed across a temperature range of 15°C to 45°C. A high activity toward AG25 (1 g/l) with relative decolorization values of 91.2% (3 h) and 97.1% (18 h), as well as high activity to AR18 (1 g/l) by 80.5% (3 h) and 89.0% (18 h), was recorded. The engineered system exhibited a comparably high activity compared with those of separate dyes in a continuous three-round shake-flask decolorization of AG25/AR18 mixed dye (each 1 g/l). No significant decline in decolorization efficacy was noted during first two-rounds but reaction equilibriums were elongated, and the residual laccase activity eventually decreased to low levels. However, the decolorizing capacity of the system was easily retrieved via a subsequent 4-h cell culturing. Conclusions This study demonstrates, for the first time, the methodology by which the engineered P. putida with surface-immobilized laccase was successfully used as regenerable biocatalyst for biodegrading synthetic dyes, thereby opening new perspectives in the use of biocatalysis in industrial dye biotreatment. PMID:22686507

Dual-tracer method to estimate coral reef response to a plume of chemically modified seawater

NASA Astrophysics Data System (ADS)

Maclaren, J. K.; Caldeira, K.

2013-12-01

We present a new method, based on measurement of seawater samples, to estimate the response of a reef ecosystem to a plume of an additive (for example, a nutrient or other chemical). In the natural environment, where there may be natural variability in concentrations, it can be difficult to distinguish between changes in concentrations that would occur naturally and changes in concentrations that result from a chemical addition. Furthermore, in the unconfined natural environment, chemically modified water can mix with waters that have not been modified, making it difficult to distinguish between effects of dilution and effects of chemical fluxes or transformations. We present a dual-tracer method that extracts signals from observations that may be affected by both natural variability and dilution. In this dual-tracer method, a substance (in our example case, alkalinity) is added to the water in known proportion to a passive conservative tracer (in our example case, Rhodamine WT dye). The resulting plume of seawater is allowed to flow over the study site. Two transects are drawn across the plume at the front and back of the study site. If, in our example, alkalinity is plotted as a function of dye concentration for the front transect, the slope of the resulting mixing line is the ratio of alkalinity to dye in the added fluid. If a similar mixing line is measured and calculated for the back transect, the slope of this mixing line will indicate the amount of added alkalinity that remains in the water flowing out of the study site per unit of added dye. The ratio of the front and back slopes indicates the fraction of added alkalinity that was taken up by the reef. The method is demonstrated in an experiment performed on One Tree Reef (Queensland, Australia) aimed at showing that ocean acidification is already affecting coral reef growth. In an effort to chemically reverse some of the changes to seawater chemistry that have occurred over the past 200 years, we added sodium hydroxide to increase alkalinity in the plume and controlled for dilution with Rhodamine WT dye. Preliminary data will be presented and analyzed using the approach described above.

Sonocatalytic degradation of malachite green oxalate by a semiconductor metal oxide nanocatalyst.

PubMed

Bhavani, R; Sivasamy, A

2016-12-01

Advanced Oxidation Process (AOP) technologies are considered to be better technique for the degradation or mineralization of many recalcitrant compounds and pollutants. In the present study heterogeneous sonocatalytic degradation of a model organic compound such as Malachite green oxalate (MGO) was carried out in the aqueous phase. Zinc oxide nanorods were prepared by precipitation method employing zinc acetates as precursors and were characterized by FT-IR, XRD, FE-SEM and EDAX analysis. Degradation of MGO in the aqueous phase was studied in detail under the sonocatalytic process. Effects of pH, dye concentration, oxidant concentration, kinetics and effect of electrolytes on dye degradation were carried out to check the efficiency of the sonocatalyst. Effect of energy input on the degradation processes was also investigated. The degradation of dye molecules were monitored by UV-visible spectrophotometer and Chemical Oxygen demand (COD). The dye molecules were readily degraded at above 90% in the pH range 5.0-7.0 under ultrasound with zinc oxide nanorods. The interference of electrolytes like NaCl, KCl, Na 2 CO 3 , NaHCO 3 and MgSO 4 on the degradation of dye molecules were also studied on the sonocatalytic degradation of MGO. From the kinetic studies it was observed that at lower initial concentration of dye molecules the degradation efficiency was above 90%. The rate of the reaction decreased on increasing the initial dye concentrations of the dye molecules. It was observed that the complete mineralization of dye molecules was achieved without the formation of toxic by-products. The reusability of the catalyst also showed the effective degradation of the dye molecules up to five cycles without loss of the catalytic activities. Copyright © 2015 Elsevier Inc. All rights reserved.

Three-dimensional structure of the curved mixing layer using image reconstruction and volume rendering

NASA Astrophysics Data System (ADS)

Karasso, P. S.; Mungal, M. G.

1991-05-01

This study investigates the structure and mixing of the two-dimensional turbulent mixing layer when subjected to longitudinal streamwise curvature. The straight layer is now well known to be dominated by the primary Kelvin-Helmholtz (KH) instability as well as the secondary Taylor-Goertler (TG) instability. For equal density fluids, placing the high-speed fluid on the inside of a streamwise bend causes the TG instability to be enhanced (unstable case), while placing the low-speed fluid on the inside of the same bend leads to the suppression of the TG instability (stable case). The location of the mixing transition is correspondingly altered. Our goal is to study the changes to the mixing field and growth rate resulting from the competition between instabilities. Our studies are performed in a newly constructed blow-down water facility capable of high Reynolds numbers and excellent optical access. Maximum flow speeds are 2 and 0.25 m/sec for the high- and low-speed sides, respectively, leading to maximum Reynolds numbers of 80 000 based on velocity difference and the width of the layer. We are able to dye one stream with a fluorescent dye, thus providing several planar views of the flow under laser sheet illumination. These views are superior to conventional approaches as they are free of wall effects and are not spatially integrating. However, our most useful diagnostic of the structure of the flow is the ability to record high-speed images of the end view of the flow that are then reconstructed by computer using the volume rendering technique of Jiménez et al.1 This approach is especially useful as it allows us to compare the structural changes to the flow resulting from the competition between the KH and TG instabilities. Another advantage is the fact that several hundred frames, covering many characteristic times, are incorporated into the rendered image and thus capture considerably more flow physics than do still images. We currently have our rendering techniques fully operational,2 and are presently acquiring high quality high-speed movies of the various flow cases. Our findings to date, based on planar time-averaged and instantaneous views, show the following: (1) a 50% increase in growth rate from the stable to the unstable case resulting from mild curvature; (2) an enhancement of the TG vortices in the unstable case, but without major disruption of the KH instability which remains relatively intact; and (3) the occurrence of the KH instability at angles tilted with respect to the splitter plate tip, in agreement with the predictions of linear stability theory. This final observation has not been reported to date, primarily because sheet techniques have not been used at Reynolds numbers as high as the present study. The presentation will provide detailed views of the changes between the stable, straight, and unstable cases using our volume rendering approach, and will provide statistical measures such as changes to vortex spacing and size, to quantify such changes.

Determination of stream reaeration coefficients by use of tracers

USGS Publications Warehouse

Kilpatrick, F.A.; Rathbun, R.E.; Yotsukura, Nobuhiro; Parker, G.W.; DeLong, L.L.

1989-01-01

Stream reaeration is the physical absorption of oxygen from the atmosphere by a flowing stream. This is the primary process by which a stream replenishes the oxygen consumed in the biodegradation of organic wastes. Prior to 1965, reaeration rate coefficients could be estimated only by indirect methods. In 1965, a direct method of measuring stream reaeration coefficients was developed whereby a radioactive tracer gas was injected into a stream-the principle being that the tracer gas would be desorbed from the stream inversely to how oxygen would be absorbed. The technique has since been modified by substituting hydrocarbon gases for the radioactive tracer gas. This manual describes the slug-injection and constant-rate-injection methods of measuring gas-tracer desorption. Emphasis is on the use of rhodamine WT dye as a relatively conservative tracer and propane as the nonconservative gas tracer, on planning field tests, on methods of injection, sampling, and analysis, and on techniques for computing desorption and reaeration coefficients.

Branched nanostructured anodes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Alayashi, Wissal

The high relative efficiency demonstrated in dye-sensitized solar cells (DSSCs) arises from a combination of light scattering within, and photo-generated electron transport through, the porous structure of a TiO2 anodes. However, the convoluted conduction path for extracting photo-generated electrons through the sponge-like structure of conventional DSSC anodes has limited further improvement. This thesis is an investigation of thin film deposited TiO2 anodes with branched tree-like structures that mimic the highly-efficient natural flow structures of trees, rivers, and the human vascular system, which can providing uninterrupted paths for photo-generated electron transport through the hierarchical branches. The main goal has been the development of a robust fabrication process for the study of DSSCs with anodes deposited with glancing angle deposition (GLAD) as it is a new area of research and the first DSSCs produced in our lab. The anodes are deposited as thin films using electron-beam evaporation with two different source of material: metallic Ti and TiO2. Ti films are shown to exhibit highly branched characteristics, with distinct branches when deposited at rate of 15 A/s versus 5 A/s (i.e. rate dependence). A thermal oxidation study for these films is performed using H2/ O2 at 450°C-520°C. For TiO2 films, post deposition annealing is performed in O2 at 450°C. Two methods are explored to create defined active areas of the films: dilute hydrofluoric acid (HF) wet etching, and lift-off lithography. DSSCs are constructed using standard components (N719 dye, I-/I3- electrolyte, and Pt cathode) paired with the photoanodes. The films are characterized by scanning electron microscopy (SEM) and x-ray diffraction (XRD). The properties of DSSCs are investigated with current density-voltage measurements (J-V). Annealed TiO2 films with thickness ranging from 1 microm-3.3 microm exhibit power conversion efficiency of DSSC of 0.5% -3.7%, respectively, which are high efficiency than GLAD DSSCs reported in the literature for coatings of this thickness. The high fill factors (0.82) indicate good shunt and series resistances for the cells, which are also higher than DSSCs reported in the literature. The enhancement in efficiency and thus in short-circuit current is attributed to good cell performance (i.e. uniform active area), increase in the specific surface area for dye adsorption, and continuous electron transport in the interconnectivity structures.

How mobile are dye adsorbates and acetonitrile molecules on the surface of TiO2 nanoparticles? A quasi-elastic neutron scattering study

PubMed Central

Vaissier, Valerie; Sakai, Victoria Garcia; Li, Xiaoe; Cabral, João T.; Nelson, Jenny; Barnes, Piers R. F.

2016-01-01

Motions of molecules adsorbed to surfaces may control the rate of charge transport within monolayers in systems such as dye sensitized solar cells. We used quasi-elastic neutron scattering (QENS) to evaluate the possible dynamics of two small dye moieties, isonicotinic acid (INA) and bis-isonicotinic acid (BINA), attached to TiO2 nanoparticles via carboxylate groups. The scattering data indicate that moieties are immobile and do not rotate around the anchoring groups on timescales between around 10 ps and a few ns (corresponding to the instrumental range). This gives an upper limit for the rate at which conformational fluctuations can assist charge transport between anchored molecules. Our observations suggest that if the conformation of larger dye molecules varies with time, it does so on longer timescales and/or in parts of the molecule which are not directly connected to the anchoring group. The QENS measurements also indicate that several layers of acetonitrile solvent molecules are immobilized at the interface with the TiO2 on the measurement time scale, in reasonable agreement with recent classical molecular dynamics results. PMID:27991538

Detecting Aspiration and Penetration Using FEES With and Without Food Dye.

PubMed

Marvin, Stevie; Gustafson, Sara; Thibeault, Susan

2016-08-01

The objective of this investigation was to determine if there were differences in identifying airway invasion (penetration or aspiration) during fiberoptic endoscopic evaluations of swallowing (FEES) for green-dyed versus non-dyed liquids. Forty adult inpatients in an acute care hospital underwent FEES, with both green-dyed liquids and naturally white liquids. Three speech-language pathologists rated aspiration and penetration for trials of nectar-thick milk and thin milk, both with and without green food dye. A subset of participants having excess pharyngeal/laryngeal secretions, as measured by the Secretions Severity Scale, were also analyzed for a difference in the detection of airway invasion and pharyngeal residue. No significant differences were found between dyes in airway invasion across all bolus types within participants. Significant differences were found in penetration ratings for large volumes of thin liquids (90 ml), between participants. When examining only discrepant airway invasion judgments for green-white swallow pairs, statistically significantly deeper airway invasion was measured for green-dyed boluses versus white for three of the five bolus types. Repeat rater reliability was better for dyed versus undyed liquids. Findings suggest that the use of green dye may allow for improved judgment of airway invasion.

How mobile are dye adsorbates and acetonitrile molecules on the surface of TiO2 nanoparticles? A quasi-elastic neutron scattering study

NASA Astrophysics Data System (ADS)

Vaissier, Valerie; Sakai, Victoria Garcia; Li, Xiaoe; Cabral, João T.; Nelson, Jenny; Barnes, Piers R. F.

2016-12-01

Motions of molecules adsorbed to surfaces may control the rate of charge transport within monolayers in systems such as dye sensitized solar cells. We used quasi-elastic neutron scattering (QENS) to evaluate the possible dynamics of two small dye moieties, isonicotinic acid (INA) and bis-isonicotinic acid (BINA), attached to TiO2 nanoparticles via carboxylate groups. The scattering data indicate that moieties are immobile and do not rotate around the anchoring groups on timescales between around 10 ps and a few ns (corresponding to the instrumental range). This gives an upper limit for the rate at which conformational fluctuations can assist charge transport between anchored molecules. Our observations suggest that if the conformation of larger dye molecules varies with time, it does so on longer timescales and/or in parts of the molecule which are not directly connected to the anchoring group. The QENS measurements also indicate that several layers of acetonitrile solvent molecules are immobilized at the interface with the TiO2 on the measurement time scale, in reasonable agreement with recent classical molecular dynamics results.

Laboratory analog and numerical study of groundwater flow and solute transport in a karst aquifer with conduit and matrix domains.

PubMed

Faulkner, Jonathan; Hu, Bill X; Kish, Stephen; Hua, Fei

2009-11-03

New mathematical and laboratory methods have been developed for simulating groundwater flow and solute transport in karst aquifers having conduits imbedded in a porous medium, such as limestone. The Stokes equations are used to model the flow in the conduits and the Darcy equation is used for the flow in the matrix. The Beavers-Joseph interface boundary conditions are adopted to describe the flow exchange at the interface boundary between the two domains. A laboratory analog is used to simulate the conduit and matrix domains of a karst aquifer. The conduit domain is located at the bottom of the transparent plexiglas laboratory analog and glass beads occupy the remaining space to represent the matrix domain. Water flows into and out of the two domains separately and each has its own supply and outflow reservoirs. Water and solute are exchanged through an interface between the two domains. Pressure transducers located within the matrix and conduit domains of the analog provide data that is processed and stored in digital format. Dye tracing experiments are recorded using time-lapse imaging. The data and images produced are analyzed by a spatial analysis program. The experiments provide not only hydraulic head distribution but also capture solute front images and mass exchange measurements between the conduit and matrix domains. In the experiment, we measure and record pressures, and quantify flow rates and solute transport. The results present a plausible argument that laboratory analogs can characterize groundwater water flow, solute transport, and mass exchange between the conduit and matrix domains in a karst aquifer. The analog validates the predictions of a numerical model and demonstrates the need of laboratory analogs to provide verification of proposed theories and the calibration of mathematical models.

Resonance Energy Transfer Studies from Derivatives of Thiophene Substituted 1,3,4-Oxadiazoles to Coumarin-334 Dye in Liquid and Dye-Doped Polymer Media

NASA Astrophysics Data System (ADS)

Naik, Lohit; Deshapande, Narahari; Khazi, Imtiyaz Ahamed M.; Malimath, G. H.

2018-02-01

In the present work, we have carried out energy transfer studies using newly synthesised derivatives of thiophene substituted 1,3,4-oxadiazoles namely, 2-(-4-(thiophene-3-yl)phenyl)-5-(5-(thiophene-3-yl)thiophene-2-yl)-1,3,4-oxadiazole [TTO], 2-(-4-(benzo[b]thiophene-2-yl)phenyl)-5-(5-(benzo[b]thiophene-2-yl)-1,3,4-oxadiozole [TBO] and 2-(4-(4-(trifluoromethyl)phenyl)phenyl)-5-(5-(4-(trifluoromethyl)phenyl)thiophen-2-yl)-1,3,4-oxadiazole [TMO] as donors and laser dye coumarin-334 as acceptor in ethanol and dye-doped polymer (poly(methyl methacrylate) (PMMA)) media following steady-state and time-resolved fluorescence methods. Bimolecular quenching constant ( k q), translation diffusion rate parameter ( k d), diffusion length ( D l), critical transfer distance ( R 0), donor- acceptor distance ( r) and energy transfer efficiency ( E T) are calculated. It is observed that, critical transfer distance is more than the diffusion length for all the pairs. Further, bimolecular quenching constant is also more than the translation diffusion rate parameter. Hence, our experimental findings suggest that overall energy transfer is due to Förster resonance energy transfer (FRET) between donor and acceptor in both the media and for all the pairs. In addition, considerable increase in fluorescence intensity and energy transfer efficiency is observed in dye-doped polymer matrix systems as compared to liquid media. This suggests that, these donor-acceptor pairs doped in PMMA matrix may be used for applications such as energy transfer dye lasers (ETDL) to improve the efficiency and photostability, to enhance tunability and for plastic scintillation detectors.

Combination of forward osmosis (FO) process with coagulation/flocculation (CF) for potential treatment of textile wastewater.

PubMed

Han, Gang; Liang, Can-Zeng; Chung, Tai-Shung; Weber, Martin; Staudt, Claudia; Maletzko, Christian

2016-03-15

A novel combination of forward osmosis (FO) process with coagulation/flocculation (CF) (FO-CF) has been experimentally conceived for the treatment and reuse of textile wastewater. FO is employed to spontaneously recover water from the wastewater via osmosis and thus effectively reduces its volume with a dramatically enhanced dye concentration. CF is then applied to precipitate and remove dyes from the FO concentrated stream with much improved efficiency and reduced chemical dosage. The FO-CF hybrid system exhibits unique advantages of high water flux and recovery rate, well controlled membrane fouling, high efficiency, and minimal environmental impact. Using a lab-made thin-film composite (TFC) FO membrane, an initial water flux (Jw) of 36.0 L m(-2) h(-1) with a dye rejection of 99.9% has been demonstrated by using 2 M NaCl as the draw solution and synthetic textile wastewater containing multiple textile dyes, inorganic salts and organic additives as the feed under the FO mode. The Jw could be maintained at a high value of 12.0 L m(-2) h(-1) even when the recovery rate of the wastewater reaches 90%. Remarkable reverse fouling behavior has also been observed where the Jw of the fouled membrane can be almost fully restored to the initial value by physical flushing without using any chemicals. Due to the great dye concentration in the FO concentrated wastewater stream, the CF process could achieve more than 95% dye removal with a small dosage of coagulants and flocculants at 500-1000 ppm. The newly developed FO-CF hybrid process may open up new exploration of alternative technologies for the effective treatment and reuse of textile effluents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows

NASA Technical Reports Server (NTRS)

Allen, M. G.; Davis, S. J.; Kessler, W. J.; Sonnenfroh, D. M.

1992-01-01

The application of Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows is analyzed. Focussing on fluorescence of the OH molecule in typical H2-air Scramjet flows, the effects of uncharacterized variations in temperature, pressure, and collisional partner composition across the measurement plane are examined. Detailed measurements of the (1,0) band OH lineshape variations in H2-air combustions are used, along with single-pulse and time-averaged measurements of an excimer-pumped dye laser, to predict the performance of a model velocimeter with typical Scramjet flow properties. The analysis demonstrates the need for modification and control of the laser bandshape in order to permit accurate velocity measurements in the presence of multivariant flow properties.

The use of vitamins as tracer dyes for laser-induced fluorescence in liquid flow applications

NASA Astrophysics Data System (ADS)

Zähringer, Katharina

2014-04-01

Tracers commonly used in experimental flow studies are mostly nocuous to the environment and human health. Particularly, in large flow installations, this can become a problem. In this study, a solution of this problem is presented, based on using water-soluble vitamins. Five of them are examined here for their applicability in flow studies. Vitamins B2 and B6 turned out to be the most promising candidates, and the dependency of their fluorescence intensity on parameters like concentration, laser energy, temperature, and pH are determined for two commonly used laser excitation wavelengths (532, 355 nm). Two examples of application in a static mixer and a spray flow are shown and demonstrate the applicability of the vitamin tracers.

Investigation of the rates of surface and bulk ROS-generating reactions using indigo dye as an indicator

NASA Astrophysics Data System (ADS)

Anderson, Carly; Clark, Douglas; Graves, David

2014-10-01

We present evidence for the existence of two distinct processes that contribute to the generation of reactive oxygen and nitrogen species (RONS) in liquids exposed to cold atmospheric plasma (CAP) in air. At the plasma-liquid interface, there exists a fast surface reaction zone where RONS from the gas phase interact with species in the liquid. RONS can also be produced by ``slow'' chemical reactions in the bulk liquid, even long after plasma exposure. To separate the effects of these processes, we used indigo dye as an indicator of ROS production; specifically generation of hydroxyl radical. The rate of indigo decolorization while in direct contact with CAP is compared with the expected rate of hydroxyl radical generation at the liquid surface. When added to aqueous solutions after CAP exposure, indigo dye reacts on a time scale consistent with the production of peroxynitrous acid, ONOOH, which is known to decompose to hydroxyl radical below a pH of 6.8. In this study, the CAP used was a air corona discharge plasma run in a positive streamer mode.

Enhanced sonochemical degradation of azure B dye by the electroFenton process.

PubMed

Martínez, Susana Silva; Uribe, Edgar Velasco

2012-01-01

The degradation of azure B dye (C15H16ClN3S; AB) has been studied by Fenton, sonolysis and sono-electroFenton processes employing ultrasound at 23 kHz and the electrogeneration of H2O2 at the reticulated vitreous carbon electrode. It was found that the dye degradation followed apparent first-order kinetics in all the degradation processes tested. The rate constant was affected by both the pH of the solution and initial concentration of Fe2+, with the highest degradation obtained at pH between 2.6 and 3. The first-order rate constant decreased in the following order: sono-electroFenton>Fenton>sonolysis. The rate constant for AB degradation by sono-electroFenton is ∼10-fold that of sonolysis and ∼2-fold the one obtained by Fenton under silent conditions. The chemical oxygen demand was abated ∼68% and ∼85% by Fenton and sono-electroFenton respectively, achieving AB concentration removal over 90% with both processes. Copyright © 2011 Elsevier B.V. All rights reserved.

Extrapolation of systemic bioavailability assessing skin absorption and epidermal and hepatic metabolism of aromatic amine hair dyes in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Manwaring, John, E-mail: manwaring.jd@pg.com; Rothe, Helga; Obringer, Cindy

Approaches to assess the role of absorption, metabolism and excretion of cosmetic ingredients that are based on the integration of different in vitro data are important for their safety assessment, specifically as it offers an opportunity to refine that safety assessment. In order to estimate systemic exposure (AUC) to aromatic amine hair dyes following typical product application conditions, skin penetration and epidermal and systemic metabolic conversion of the parent compound was assessed in human skin explants and human keratinocyte (HaCaT) and hepatocyte cultures. To estimate the amount of the aromatic amine that can reach the general circulation unchanged after passagemore » through the skin the following toxicokinetically relevant parameters were applied: a) Michaelis–Menten kinetics to quantify the epidermal metabolism; b) the estimated keratinocyte cell abundance in the viable epidermis; c) the skin penetration rate; d) the calculated Mean Residence Time in the viable epidermis; e) the viable epidermis thickness and f) the skin permeability coefficient. In a next step, in vitro hepatocyte K{sub m} and V{sub max} values and whole liver mass and cell abundance were used to calculate the scaled intrinsic clearance, which was combined with liver blood flow and fraction of compound unbound in the blood to give hepatic clearance. The systemic exposure in the general circulation (AUC) was extrapolated using internal dose and hepatic clearance, and C{sub max} was extrapolated (conservative overestimation) using internal dose and volume of distribution, indicating that appropriate toxicokinetic information can be generated based solely on in vitro data. For the hair dye, p-phenylenediamine, these data were found to be in the same order of magnitude as those published for human volunteers. - Highlights: • An entirely in silico/in vitro approach to predict in vivo exposure to dermally applied hair dyes • Skin penetration and epidermal conversion assessed in human skin explants and HaCaT • Systemic metabolism was modeled using hepatocyte cultures. • Toxicokinetically relevant parameters were applied to estimate systemic exposure. • There was a good agreement between in vitro and in vivo data.« less

Remote and In Situ Observations of Surfzone and Inner-Shelf Tracer Dispersion

NASA Astrophysics Data System (ADS)

Hally-Rosendahl, K.; Feddersen, F.; Clark, D.; Guza, R. T.

2014-12-01

Surfzone and inner-shelf tracer dispersion was observed at the approximately alongshore-uniform Imperial Beach, California during the IB09 experiment. Rhodamine dye tracer, released continuously near the shoreline for several hours, was advected alongshore by breaking wave- and wind-driven currents, and ejected offshore from the surfzone to the inner-shelf by transient rips. Aerial multispectral imaging of inner-shelf dye concentration complemented in situ surfzone and inner-shelf measurements of dye, temperature, waves, and currents, providing tracer transport and dispersion observations spanning approximately 400 m cross-shore and 3 km alongshore. Combined in situ and aerial measurements approximately close a surfzone and inner-shelf dye budget. Mean alongshore dye dilution follows a power-law relationship, and both spatial and temporal dye variability decrease with distance from the release. Aerial images reveal coherent inner-shelf dye plume structures extending over 300 m offshore with alongshore length scales up to 400 m. Plume tracking among successive images yields inner-shelf alongshore advection rates consistent with in situ observations. Alongshore advection is faster within the surfzone than on the inner-shelf, and the leading alongshore edge of inner-shelf dye is due to local transient rip ejections from the surfzone. A combination of in situ and aerial surfzone and inner-shelf measurements are used to quantify cross- and alongshore dye tracer transports. This work is funded by NSF (including a Graduate Research Fellowship, Grant No. DGE1144086), ONR, and California Sea Grant. Figure: Aerial multispectral image of surface dye concentration (parts per billion, see colorbar) versus cross-shore coordinate x and alongshore coordinate y, approximately 5 hours after the start of a continuous dye release (green star). The mean shoreline is at x=0 m. Dark gray indicates the beach and a pier, and light gray indicates regions outside the imaged area. Black indicates unresolved regions due to foam from wave breaking. Vertical dashed line delimits the surfzone (SZ) and inner-shelf (IS). Yellow diamonds indicate locations of in situ measurements of dye, temperature, waves, and currents. Yellow circles indicate locations of in situ dye and temperature measurements.

Removal of unwanted fluid

NASA Astrophysics Data System (ADS)

Subudhi, Sudhakar; Sreenivas, K. R.; Arakeri, Jaywant H.

2013-01-01

This work is concerned with the removal of unwanted fluid through the source-sink pair. The source consists of fluid issuing out of a nozzle in the form of a jet and the sink is a pipe that is kept some distance from the source pipe. Of concern is the percentage of source fluid sucked through the sink. The experiments have been carried in a large glass water tank. The source nozzle diameter is 6 mm and the sink pipe diameter is either 10 or 20 mm. The horizontal and vertical separations and angles between these source and sink pipes are adjustable. The flow was visualized using KMnO4 dye, planer laser induced fluorescence and particle streak photographs. To obtain the effectiveness (that is percentage of source fluid entering the sink pipe), titration method is used. The velocity profiles with and without the sink were obtained using particle image velocimetry. The sink flow rate to obtain a certain effectiveness increase dramatically with lateral separation. The sink diameter and the angle between source and the sink axes don't influence effectiveness as much as the lateral separation.

Physiological analysis of yeast cells by flow cytometry during serial-repitching of low-malt beer fermentation.

PubMed

Kobayashi, Michiko; Shimizu, Hiroshi; Shioya, Suteaki

2007-05-01

At the end of beer brewing fermentation, yeast cells are collected and repitched for economical reasons. Although it is generally accepted that the physiological state of inoculated yeast cells affects their subsequent fermentation performance, the effect of serial-repitching on the physiological state of such yeast cells has not been well clarified. In this study, the fermentation performance of yeast cells during serial-repitching was investigated. After multiple repitchings, the specific growth rate and maximum optical density (OD(660)) decreased, and increases in isoamyl alcohol, which causes an undesirable flavor, and residual free amino acid nitrogen (FAN) concentrations were observed. The physiological state of individual cells before inoculation was characterized by flow cytometry using the fluorescent dyes dehydrorhodamine 123 (DHR) and bis-(1,3-dibutylbarbituric acid) trimethine oxonol (OXN). The fluorescence intensities of DHR, an indicator of reactive oxygen species (ROSs), and OXN, which indicates membrane potential, gradually increased as the number of serial-repitching cycles increased. Fluorescence intensity correlated strongly with cell growth. The subsequent fermentation performance can be predicted from this correlation.

Measurement of Submerged Oil/Gas Leaks using ROV Video

NASA Astrophysics Data System (ADS)

Shaffer, Franklin; de Vera, Giorgio; Lee, Kenneth; Savas, Ömer

2013-11-01

Drilling for oil or gas in the Gulf of Mexico is increasing rapidly at depths up to three miles. The National Commission on the Deepwater Horizon Oil Leak concluded that inaccurate estimates of the leak rate from the Deepwater Horizon caused an inadequate response and attempts to cap the leak to fail. The first response to a submerged oil/gas leak will be to send a Remotely Operated Vehicle (ROV) down to view the leak. During the response to the Deepwater Horizon crisis, the authors Savas and Shaffer were members of the Flow Rate Technical Group's Plume Team who used ROV video to develop the FRTG's first official estimates of the oil leak rate. Savas and Shaffer developed an approach using the larger, faster jet features (e.g., turbulent eddies, vortices, entrained particles) in the near-field developing zone to measure discharge rates. The authors have since used the Berkeley Tow Tank to test this approach on submerged dye-colored water jets and compressed air jets. Image Correlation Velocimetry has been applied to measure the velocity of visible features. Results from tests in the Berkeley Tow Tank and submerged oil jets in the OHMSETT facility will be presented.

Cosensitization of D-A-π-A quinoxaline organic dye: efficiently filling the absorption valley with high photovoltaic efficiency.

PubMed

Pei, Kai; Wu, Yongzhen; Li, Hui; Geng, Zhiyuan; Tian, He; Zhu, Wei-Hong

2015-03-11

In the efficient cosensitization, the pure organic sensitizers with high molecular extinction coefficients and long wavelength response are highly preferable since the dye loading amount for each dye in cosensitization is decreased with respect to single dye sensitization. A D-A-π-A featured quinoxaline organic sensitizer IQ21 is specifically designed. The high conjugation building block of 4H-cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) is introduced as the π bridge, instead of the traditional thiophene unit, especially in realizing high molecular extinction coefficients (up to 66 600 M(-1) cm(-1)) and extending the light response wavelength. With respect to the reference dye IQ4, the slightly lower efficiency of IQ21 (9.03%) arises from the decrease of VOC, which offsets the gain in JSC. While cosensitized with a smaller D-π-A dye S2, the efficiency in IQ21 is further improved to 10.41% (JSC = 19.8 mA cm(-2), VOC = 731 mV, FF = 0.72). The large improvement in efficiency is attributed to the well-matched molecular structures and loading amounts of both dyes in the cosensitization system. We also demonstrated that coabsorbent dye S2 can distinctly compensate the inherent drawbacks of IQ21, not only enhancing the response intensity of IPCE, making up the absorption defects around low wavelength region of IPCE, but also repressing the charge recombination rate to some extent.

High-repetition-rate, narrow-band dye lasers with water as a solvent for dyes

NASA Astrophysics Data System (ADS)

Ray, Alok K.; Sinha, Sucharita; Kundu, Soumitra; Kumar, Sasi; Nair, Sivagiriyal Karunakaran Sreenivasan; Pal, Tamal; Dasgupta, Kamalesh

2002-03-01

The performance of a copper vapor laser-pumped narrow-band dye laser in oscillator-amplifier configuration with water-based binary mixture solvents is described. Although oscillator efficiency in water-surfactant (sodium lauryl sulfate) solvent was comparable with that that employed pure ethanolic solvent, amplifier efficiency was found to be lower. Experiments that were carried out with vertically polarized pump beams and either horizontally or vertically polarized signal beams show that, in case of both the pump and signal having orthogonal polarization (horizontal) and same polarization (vertical), the extraction efficiency for both ethanolic and water-micelle media increased substantially from 15.7% to 18.5% and from 10% to 12.5%, respectively. However, the relative difference remained nearly the same, indicating that a slower orientational diffusion of excited dye molecules in a micellar medium is not responsible for a decrease in amplifier efficiency. Amplifier efficiency comparable with that containing ethanolic dye solutions could be obtained with a binary solvent that comprises a mixture of water and about 30% n-propanol. The performances of two efficient dyes, Rhodamine-6G and Kiton Red S, using water-based solvents were studied.

Laccase/mediator assisted degradation of triarylmethane dyes in a continuous membrane reactor.

PubMed

Chhabra, Meenu; Mishra, Saroj; Sreekrishnan, Trichur Ramaswamy

2009-08-10

Laccase/mediator systems are important bioremediation agents as the rates of reactions can be enhanced in the presence of the mediators. The decolorization mechanism of two triarylmethane dyes, namely, Basic Green 4 and Acid Violet 17 is reported using Cyathus bulleri laccase. Basic Green 4 was decolorized through N-demethylation by laccase alone, while in mediator assisted reactions, dye breakdown was initiated from oxidation of carbinol form of the dye. Benzaldehyde and N,N-dimethyl aniline were the major end products. With Acid Violet 17, laccase carried out N-deethylation and in mediator assisted reactions, oxidation of the carbinol form of the dye occurred resulting in formation of formyl benzene sulfonic acid, carboxy benzene sulfonic acid and benzene sulfonic acid. Toxicity analysis revealed that Basic Green 4 was toxic and treatment with laccase/mediators resulted in 80-100% detoxification. The treatment of the textile dye solution using laccase and 2,2'-azino-di-(-ethylbenzothiazoline-6-sulfonic acid) (ABTS) was demonstrated in an enzyme membrane reactor. At a hydraulic retention time of 6h, the process was operated for a period of 15 days with nearly 95% decolorization, 10% reduction in flux and 70% recovery of active ABTS.

Synthesis, Characterization and Reactivity of Nanostructured Zero-Valent Iron Particles for Degradation of Azo Dyes

NASA Astrophysics Data System (ADS)

Mikhailov, Ivan; Levina, Vera; Leybo, Denis; Masov, Vsevolod; Tagirov, Marat; Kuznetsov, Denis

Nanostructured zero-valent iron (NSZVI) particles were synthesized by the method of ferric ion reduction with sodium borohydride with subsequent drying and passivation at room temperature in technical grade nitrogen. The obtained sample was characterized by means of X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and dynamic light scattering studies. The prepared NSZVI particles represent 100-200nm aggregates, which consist of 20-30nm iron nanoparticles in zero-valent oxidation state covered by thin oxide shell. The reactivity of the NSZVI sample, as the removal efficiency of refractory azo dyes, was investigated in this study. Two azo dye compounds, namely, orange G and methyl orange, are commonly detected in waste water of textile production. Experimental variables such as NSZVI dosage, initial dye concentration and solution pH were investigated. The kinetic rates of degradation of both dyes by NSZVI increased with the decrease of solution pH from 10 to 3 and with the increase of NSZVI dosage, but decreased with the increase of initial dye concentration. The removal efficiencies achieved for both orange G and methyl orange were higher than 90% after 80min of treatment.

Ultrafast adsorption and selective desorption of aqueous aromatic dyes by graphene sheets modified by graphene quantum dots

NASA Astrophysics Data System (ADS)

Ying, Yulong; He, Peng; Ding, Guqiao; Peng, Xinsheng

2016-06-01

Graphene modified by graphene quantum dots (GQDs) has been employed to remove toxic organic dyes. An excellent removal capacity (497 mg g-1) and record-breaking adsorption rate (475 mg g-1 min-1 at 20 °C) were demonstrated for Rhodamine B. The enhancement in performance by nearly a factor of three compared to that of graphene was ascribed to the greatly increased accessible surface area of graphene in aqueous solution as well as the increase in surface charges with the modification with GQDs. Besides, this unique adsorption behavior of the modified graphene was expanded to other typical toxic aqueous aromatic dyes such as Evans Blue, Methyl Orange, Malachite Green and Rose Bengal. What is more, a unique desorption behavior of dyes was first observed when employing different solvents, which enabled the GQD-modified graphene to be exploited for selective extraction of dyes and recycling of the adsorbent. The adsorption and desorption mechanism were further investigated. Combining high removal capacity, rapid adsorption kinetics, good recyclability and unique selective desorption, GQD-modified graphene has potential applications in both water purification and separation of aromatic dyes.

Dye-Enhanced Self-Electrophoretic Propulsion of Light-Driven TiO2-Au Janus Micromotors

NASA Astrophysics Data System (ADS)

Wu, Yefei; Dong, Renfeng; Zhang, Qilu; Ren, Biye

2017-07-01

Light-driven synthetic micro-/nanomotors have attracted considerable attention in recent years due to their unique performances and potential applications. We herein demonstrate the dye-enhanced self-electrophoretic propulsion of light-driven TiO2-Au Janus micromotors in aqueous dye solutions. Compared to the velocities of these micromotors in pure water, 1.7, 1.5, and 1.4 times accelerated motions were observed for them in aqueous solutions of methyl blue (10-5 g L-1), cresol red (10-4 g L-1), and methyl orange (10-4 g L-1), respectively. We determined that the micromotor speed changes depending on the type of dyes, due to variations in their photodegradation rates. In addition, following the deposition of a paramagnetic Ni layer between the Au and TiO2 layers, the micromotor can be precisely navigated under an external magnetic field. Such magnetic micromotors not only facilitate the recycling of micromotors, but also allow reusability in the context of dye detection and degradation. In general, such photocatalytic micro-/nanomotors provide considerable potential for the rapid detection and "on-the-fly" degradation of dye pollutants in aqueous environments.

The false-negative rate of sentinel node biopsy in patients with breast cancer: a meta-analysis

PubMed Central

Pesek, Sarah; Ashikaga, Taka; Krag, Lars Erik; Krag, David

2012-01-01

Background/Purpose In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate. Methods We found 3588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published. Results There was significant variation in the false-negative rate over time with a trend to higher rates over time. There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant. This meta-analysis also indicates a significant change over time in the false-negative rate. Discussion/Conclusions The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control. PMID:22569745

On the possible long-term fate of oil released in the deepwater horizon incident: estimated by ensembles of dye release simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maltrud, Mathew E.; Peacock, Synte L.; Visbeck, Martin

2010-08-01

We have conducted an ensemble of 20 simulations using a high-resolution global ocean model in which dye was continuously injected at the site of the Deepwater Horizon drilling rig for two months. We then extended these simulations for another four months to track the dispersal of the dye in the model. We have also performed five simulations in which dye was continuously injected at the site of the spill for four months and then run out to one year from the initial spill date. The experiments can elucidate the time and space scales of dispersal of polluted waters and alsomore » give a quantitative estimate of dilution rate, ignoring any sink terms such as chemical or biological degradation.« less

Dissolved oxygen sensing using organometallic dyes deposited within a microfluidic environment

NASA Astrophysics Data System (ADS)

Chen, Q. L.; Ho, H. P.; Jin, L.; Chu, B. W.-K.; Li, M. J.; Yam, V. W.-W.

2008-02-01

This work primarily aims to integrate dissolved oxygen sensing capability with a microfluidic platform containing arrays of micro bio-reactors or bio-activity indicators. The measurement of oxygen concentration is of significance for a variety of bio-related applications such as cell culture and gene expression. Optical oxygen sensors based on luminescence quenching are gaining much interest in light of their low power consumption, quick response and high analyte sensitivity in comparison to similar oxygen sensing devices. In our microfluidic oxygen sensor device, a thin layer of oxygen-sensitive luminescent organometallic dye is covalently bonded to a glass slide. Micro flow channels are formed on the glass slide using patterned PDMS (Polydimethylsiloxane). Dissolved oxygen sensing is then performed by directing an optical excitation probe beam to the area of interest within the microfluidic channel. The covalent bonding approach for sensor layer formation offers many distinct advantages over the physical entrapment method including minimizing dye leaching, ensuring good stability and fabrication simplicity. Experimental results confirm the feasibility of the device.

Determination of reaeration-rate coefficients of the Wabash River, Indiana, by the modified tracer technique

USGS Publications Warehouse

Crawford, Charles G.

1985-01-01

The modified tracer technique was used to determine reaeration-rate coefficients in the Wabash River in reaches near Lafayette and Terre Haute, Indiana, at streamflows ranging from 2,310 to 7,400 cu ft/sec. Chemically pure (CP grade) ethylene was used as the tracer gas, and rhodamine-WT dye was used as the dispersion-dilution tracer. Reaeration coefficients determined for a 13.5-mi reach near Terre Haute, Indiana, at streamflows of 3,360 and 7,400 cu ft/sec (71% and 43% flow duration) were 1.4/day and 1.1/day at 20 C, respectively. Reaeration-rate coefficients determined for a 18.4-mile reach near Lafayette, Indiana, at streamflows of 2,310 and 3,420 cu ft/sec (70% and 53 % flow duration), were 1.2/day and 0.8/day at 20 C, respectively. None of the commonly used equations found in the literature predicted reaeration-rate coefficients similar to those measured for reaches of the Wabash River near Lafayette and Terre Haute. The average absolute prediction error for 10 commonly used reaeration equations ranged from 22% to 154%. Prediction error was much smaller in the reach near Terre Haute than in the reach near Lafayette. The overall average of the absolute prediction error for all 10 equations was 22% for the reach near Terre Haute and 128% for the reach near Lafayette. Confidence limits of results obtained from the modified tracer technique were smaller than those obtained from the equations in the literature.